May 31, 2017 - WP4: Development of a Novel Wastewater Treatment Facility . ...... If storage is unavailable onsite, excess manures can be transported to offsite ...
D6.2 Biomass Supply Chain Evaluation
Deliverable 6.2 DISCLAIMER The opinion stated in this report reflects the opinion of the authors and not the opinion of the European Commission. All intellectual property rights are owned by AgroCycle consortium members and are protected by the applicable laws. Reproduction is not authorised without prior written agreement. The commercial use of any information contained in this document may require a license from the owner of that information. ACKNOWLEDGEMENT This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement Nº 690142. 2
Deliverable 6.2 Deliverable Document Sheet Project Acronym AgroCycle Project Title Sustainable techno-economic solutions for the agricultural value chain Grant Agreement number 690142 Call identifier H2020-WASTE-2015-two-stage Topic identifier WASTE-7-2015 Ensuring sustainable use of agricultural waste, co-products and by-products Funding Scheme Research and Innovation Action Project duration 36 months (June 2016 – May 2019) Coordinator NUID UCD – Professor Shane Ward Website www.AgroCycle.eu Deliverable No. D6.2 Deliverable title Biomass supply chain evaluation Description Full characterisation of the available AWCB and their current treatment methods or uses, and related systems WP No. WP6 Related task WP6.5 Lead Beneficiary NNFCC Author(s) Sophie Mason and Dr Caitlin Burns, NNFCC Contributor(s) Prof. Karabelas Anastasios, Dr. Nick Holden, Tom Oldfield, Dr. Fionnuala Murphy, Dr Sotiris Patsios, Dr Cristina Righetti, Andreas Stäbler, Matthias Reinelt, Dr Trisha Troop, Dr Michael Theodorou, Dr Dimitris Katsantonis, Boris Cosic Type Report Dissemination Level Public Language English – GB Due Date 31.5.17 Submission Date 26.7.2017 Date:
Action:
Version:
Ownership:
Written
V.1
25.07.217
Reviewed/amended/approved V.2 Submitted via Online Portal to V.2 Funding Agency Reviewed/amended/approved V.3
Sophie Mason and Dr Caitlin Burns Dr Caitlin Burns Ger Hanley
27.07.2017 27.09.2017
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Sophie Mason
Deliverable 6.2
Table of Contents 1. Introduction .................................................................................................. 11 2. Current Uses of AWCB in Europe ................................................................... 12 AWCB supply chains in Europe .................................................................... 12 Production and utilisation of AWCB in the EU overview .................................. 12 Livestock AWCB ........................................................................................... 14 Manure production .......................................................................................... 15 Typical manure management and use ............................................................ 16 Cereal and oil seed AWCB ............................................................................ 17 Production of straw ......................................................................................... 18 Typical straw management and use ................................................................ 19 Fruit AWCB .................................................................................................. 20 Fruit production and processing ...................................................................... 21 Typical fruit pomace management and use .................................................... 23 Vegetable AWCB .......................................................................................... 24 Production of vegetable AWCBs ...................................................................... 25 Typical vegetable AWCB management and uses............................................. 26
3. AgroCycle Pathways Overview ...................................................................... 28 4. WP2: Small Scale AD Facility Processing Mixed AWCB ................................... 30 Novel Pathway Description .......................................................................... 30 Summary of Pathway ...................................................................................... 30 AD Pathway Feedstocks ................................................................................... 31 AD Pathway Logistics ....................................................................................... 33 AD Pathway Products ...................................................................................... 35 Current Supply Chains of AD Pathway Feedstocks: Manure ....................... 38 Fertiliser Applications of FYM .......................................................................... 38 Bioenergy Applications of FYM ........................................................................ 40 Potential Markets for Novel AgroCycle Products ........................................ 43 UK AD Market Size ........................................................................................... 43 Market Potential of AD Outputs ...................................................................... 45 AD Market Incentives ...................................................................................... 58 Market Displacement .................................................................................. 60 Possible Markets Displaced by Biogas ............................................................. 60 Possible Markets Displaced by Digestate ........................................................ 62 WP2: Closing Remarks ................................................................................. 62
5. WP3: Developing Novel Biofertilisers from Rice Bran ..................................... 64 Novel Pathway Description .......................................................................... 65 Summary of Pathway ...................................................................................... 65 Rice Bran Pathway Feedstocks ........................................................................ 66 Rice Bran Logistics ........................................................................................... 68 Rice Bran Valorisation and Products ............................................................... 69 Current Supply Chains of Pathway Feedstocks: Rice Bran ........................... 71 Animal Consumption of Rice Bran ................................................................... 71 Human Consumption/Application of Rice Bran ............................................... 72 Potential Markets for Novel AgroCycle Products ........................................ 73 Greek Rice Market ........................................................................................... 73
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Deliverable 6.2 Greek Fertiliser Market .................................................................................... 76 Greek Compost Market .................................................................................... 78 Potential Markets Displaced by AgroCycle Products ................................... 79 Displacement of Existing Fertiliser Markets .................................................... 79 Displacement by Animal Feed Markets ........................................................... 82 Displacement of Rice Markets ......................................................................... 83 WP3: Closing Remarks ................................................................................. 83
6. WP4: Development of a Novel Wastewater Treatment Facility ...................... 86 Novel Pathway Description .......................................................................... 86 Summary ......................................................................................................... 86 Fruit Wastewater Production .......................................................................... 91 Wastewater Logistics ...................................................................................... 93 Wastewater Valorisation and Products ........................................................... 94 Current Wastewater Supply Chain .............................................................. 95 Primary Wastewater Treatment ...................................................................... 96 Secondary Wastewater Treatment .................................................................. 97 Tertiary Wastewater Treatment ...................................................................... 98 Potential Markets for Novel AgroCycle Products ........................................ 98 Greek Fruit Processing Markets ....................................................................... 98 Novel System Outputs ................................................................................... 103 Potential Markets Displaced by the Novel AgroCycle System ................... 120 Displacement of Existing Protein Products .................................................... 121 Displacement of Existing Clean Water Processes .......................................... 122 Displacement of Fossil Derived Energy .......................................................... 122 Closing Remarks ......................................................................................... 124
7. WP5 Developing Novel Biocomposites from Potato Pulp ............................. 126 Novel Pathway Description ........................................................................ 126 Summary of Pathway .................................................................................... 126 Biocomposite Pathway Feedstocks: Fibrous Potato Pulp .............................. 128 Potato Pulp Logistics ..................................................................................... 129 Potato Fibre Valorisation and Products ......................................................... 130 Current Potato Pulp Supply Chains ............................................................ 131 Animal Consumption of Potato Pulp .............................................................. 131 Other Uses of Potato Pulp ............................................................................. 132 Wasted Potato Pulp ....................................................................................... 132 Markets of novel Products ......................................................................... 133 Italian Plant and Flower Markets .................................................................. 133 Italian Plant Pot Markets ............................................................................... 134 Italian Plant Pot Costs .................................................................................... 136 Italian Plant Pot Market Incentives ............................................................... 136 Italian Biocomposite Market ......................................................................... 137 Italian Potato Markets ................................................................................... 139 Starch production in the EU ........................................................................... 140 Markets Displaced ..................................................................................... 141 Displacement of Plastic Plant Pots ................................................................ 141 WP5: Closing Remarks ............................................................................... 144
8. References .................................................................................................. 145
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Deliverable 6.2
List of Tables Table 1: Typical biogas yields available from different types of biomass (NNFCC, Feedstocks, 2017). ................................................................................................................................ 33 Table 2: Dry matter content of typical AD feedstocks (NNFCC, 2017). ................................... 34 Table 3: Typical nutrient values contained within AD digestates (NNFCC, 2017). .................. 35 Table 4: Nitrate limits for various compounds within NVZs in the UK (2017) (DEFRA, 2017). 39 Table 5: Typical amounts of nitrogen, phosphate, potash, sulphur and magnesium contained in fresh weights of manures (DEFRA, 2010). ..................................................................... 40 Table 6: Electricity generated from bioenergy in the UK (2010-2015) (BEIS, 2017) ............... 49 Table 7: AD feed in tariffs (NNFCC, 2017) ............................................................................... 59 Table 8: UK wide RHI tariff table (Ofgem, 2017) ..................................................................... 59 Table 9. Quantities of each compound typically required for the fertilisation of Greek soils (D.Ntanos, 2017). .............................................................................................................. 66 Table 10: Nutritional composition of stabilised full fat rice bran (Rao, 2000) ........................ 70 Table 11: Highlights land area dedicated to the two main varieties of rice, Japonica and Indica, in each rice producing country within Europe (EuropeanCommision, 2015). .................. 76 Table 12: Potential revenue obtainable from selling composts in Greece (ΣΕΚ, 2012). ......... 79 Table 13: Overview of the costs related to a traditional 100,000 m3/d wastewater treatment facility (CostWater, 2017). .............................................................................................. 103 Table 14. Full breakdown of energy mix consumed in Greece in 2015 (Eurostat) ................ 123
List of Figures Figure 1. Grazing cattle ........................................................................................................... 12 Figure 2. Average annual quantities across the EU-28 of all the selected AWCB analysed in this report (2010-2013). ........................................................................................................... 13 Figure 3. Sugar beet ................................................................................................................ 14 Figure 4. Typical cattle AWCB production ............................................................................... 15 Figure 5. Examples of farm yard manure and slurry ............................................................... 15 Figure 6. Total quantities of manure analysed across the EU-28 ............................................ 16 Figure 7. Typical current value chain of manure ..................................................................... 17 Figure 8. Typical rice AWCB production .................................................................................. 18 Figure 9. Straw bale in field ..................................................................................................... 18 Figure 10. Annual average quantities of straw analysed across the EU-28 (2010-2013) ........ 19 Figure 11. System map of typical straw value chains .............................................................. 20 Figure 12. Typical fruit processing schematic ......................................................................... 21 Figure 13. Average tonnes of fruit harvested across the EU annually (2010-2015) ................ 22 Figure 14. Average tonnes of fruit processed across the EU annually (2010-2013) ............... 23 Figure 15. Apple pomace ......................................................................................................... 23 Figure 16. System map of typical fruit pomace value chains .................................................. 24 Figure 17. Typical potato skin AWCB production .................................................................... 25 Figure 18. Average annual quantities of analysed sugar beet pulp across the EU-28 (20102013) ................................................................................................................................. 25 6
Deliverable 6.2 Figure 19. Average annual quantities of analysed vegetable peels and leaves across the EU-28 (2010-2013) ....................................................................................................................... 26 Figure 20. System map of typical vegetable AWCB value chains ........................................... 27 Figure 21. Schematic of typical anaerobic digestion value chains .......................................... 31 Figure 22: Growth of AD feedstocks used throughout the UK* .............................................. 32 Figure 23: Pressure swing adsorption facility schematic highlighting how CH4 can be produced after treatment with the AD facility. Figure adapted from (Zafar, 2016). ........................ 36 Figure 24: Overview of the products and processes occurring within a general anaerobic digestion system (PlanET, 2017). ...................................................................................... 37 Figure 25: Average annual UK animal AWCB production for poultry, pigs, cattle and dairy cows. .......................................................................................................................................... 38 Figure 26: Pathways overview for existing animal manures/slurry supply chains in the UK. Components outlined in red highlight the primary outputs of the existing systems. ....... 42 Figure 27: Map of all AD projects within the UK (2017) (NNFCC, 2017). ................................ 43 Figure 28. Number of AD plants (diamonds) and installed capacity (bars) by size of plant* .. 44 Figure 29. Deployment of biomethane facilities in the UK and installed capacity .................. 45 Figure 30: UK trends in the use of renewable energy across heat, electricity and transport sectors (DECC, 2016) ......................................................................................................... 46 Figure 31. Renewable energy use 2015 (BEIS, 2016). ............................................................. 47 Figure 32: Total energy mix for electricity production in the UK for Q1-4, 2013-2016 (BEIS, Energy Trends, 2017). ....................................................................................................... 48 Figure 33: Total renewable electricity capacity since 2000 (BEIS, 2016) ................................ 48 Figure 34: The share of GHG emissions produced by the domestic, industrial and commercial sectors. .............................................................................................................................. 50 Figure 35. Heat paid for under the domestic and non-domestic Renewable Heat Incentive schemes, cumulative since November 2012 up to March 2016. ...................................... 50 Figure 36: UK demand for natural gas from 2013-2016 (BEIS, 2017). ..................................... 51 Figure 37. Import and export of gas by the UK ....................................................................... 52 Figure 38: Proportion of feedstocks used by biomethane projects around the UK by the end of 2016 (Baldwin, 2016). ....................................................................................................... 53 Figure 39. Demand for key transport fuels (BEIS, 2017) ......................................................... 53 Figure 40: Final consumption of oil from 2013 to 2016 (BEIS, 2017). ..................................... 54 Figure 41. Bio-Bus in Bristol, powered by sewage and household food waste anaerobic digestion ............................................................................................................................ 54 Figure 42. Volumes of renewable fuels, by fuel type (DFT, 2017). .......................................... 55 Figure 43. PAS110 certified digestate, by nation (tonnes) time series (NNFCC, 2017b) ......... 56 Figure 44: Potential uses and resultant markets that digestates materials can enter (WRAP, 2012). ................................................................................................................................ 57 Figure 45: UK indigenous primary fuel production 2015 vs 2016 (BEIS, 2017). ...................... 61 Figure 46: Illustration of the proposed AgroCycle value chain for the novel application of rice bran/husk. ......................................................................................................................... 65 Figure 47: Distribution of rice production across Europe in 2014 (FAOSTAT, Crops, 2017) .... 66 Figure 48. Development of rice across the three primary stages of crop development (RiceKnowledgeBank, 2017) .............................................................................................. 67 Figure 49 Key components of a rice grain ............................................................................... 68 7
Deliverable 6.2 Figure 50: Typical composition of a standard rice grain .......................................................... 68 Figure 51: The three stages of thermophilic composting (Cornell, 2017). .............................. 69 Figure 52: An existing supply chain for the use of rice bran in Greece. .................................. 72 Figure 53: Top rice paddy producing nations within the EU 28 in 2014 (FAOSTAT, Crops, 2017). .......................................................................................................................................... 73 Figure 54: Rice production and consumption in Greece from (1980-2014) (FAOSTAT, Crops, 2017) (Ricepedia, 2017). ................................................................................................... 74 Figure 55: Import and export quantities of rice in Greece from 1980-2014 (FAOSTAT, Crops, 2017). ................................................................................................................................ 75 Figure 56: Import and export values of rice in Greece from 1980-2014 (FAOSTAT, Crops, 2017). .......................................................................................................................................... 75 Figure 57: Annual quantities of NPK fertilisers used in rice paddy production in Greece (Ricepedia, 2017). ............................................................................................................. 77 Figure 58: Import and export values associated with NPK fertilisers in Greece (FAOSTAT, Crops, 2017). ................................................................................................................................ 77 Figure 59: Greek recycling of municipal solid wastes (MSW) (I. Bakas, 2013) ........................ 78 Figure 60: European nations with the best composting performances compared with that of Greece (ΣΕΚ, 2012) ............................................................................................................ 78 Figure 61: A typical potassium cycle used for the fertilization of crops (IPNI, 2010). ............. 80 Figure 62: Traditional salt water brine, where salt accumulates from waters and acts as a source for mineral recovery (IPNI, 2010). ......................................................................... 81 Figure 63: Market sector breakdown of the EU chemical industry (Cefic, 2015). ................... 82 Figure 64: Proposed pathway for a novel fruit processed wastewater facility. ...................... 89 Figure 65: EU28 waste generation, excluding major mineral wastes, for the period 2004-2014 in million tonnes (EuroStat, 2016). ................................................................................... 91 Figure 66: A proposed value chain for the general production of fruit waste waters during processing. ........................................................................................................................ 92 Figure 67: Flotation chamber for cleaning apples (OnApples, 2015) ...................................... 92 Figure 68: A typical drainage system fitted within a food processing facility (ACO, 2016) ..... 93 Figure 69: Representation of typical membrane bioreactor used in the treatment of wastewaters (MembraneSolutions, 2017). ....................................................................... 95 Figure 70: Current supply chain for processing wastewaters in Greece. ................................ 95 Figure 71: Visual representation of the stable and unstable colloidal mixtures possible in fruit processing wastewaters. ................................................................................................... 96 Figure 72: General representation of a typical activated sludge process (Grassroots, 2010). 97 Figure 73: Peach, kiwi, apple and pear production in Greece (1960-2016) (FAOSTAT, Crops, 2017). ................................................................................................................................ 99 Figure 74: Top 10 crops produced in Greece in 2014 (FAOSTAT, Crops, 2017). ...................... 99 Figure 75: Top 10 global peach producers in 2014 (FAOSTAT, Crops, 2017). ....................... 100 Figure 76: Highlights the average annual rainfall in Greece in the period from 1900 to 2014 (World-Bank, 2017). ........................................................................................................ 101 Figure 77: Kiwi production in Greece from 1980-2014 (FAOSTAT, Crops, 2017). ................. 102 Figure 78: Top 10 global kiwi producing nations (FAOSTAT, Crops, 2017). ........................... 102 Figure 79: Visual breakdown of the costs associated with the conventional treatment of wastewaters (CostWater, 2017). .................................................................................... 103 8
Deliverable 6.2 Figure 80: Calories from major commodities in developing countries (FAO, 2017) ............. 104 Figure 81: Protein supply quantity in both Greece and the World (g/capita/day) (FAO, 2017) ........................................................................................................................................ 105 Figure 82: Global demand for meat in 2005 vs projected 2050 (tonnes) (Gates, 2013). ...... 105 Figure 83: Consumer price indices for food and general commodities in Greece from 20142016 (FAOSTAT, 2017). ................................................................................................... 106 Figure 84: Annual price indices for both meat and dairy products from 2005-2017* (FAOSTAT, 2017) ............................................................................................................................... 107 Figure 85: Global growth in demand for animal feed (Speedy, 2000) .................................. 108 Figure 86. Livestock sourcing tonnes of feed in the EU-27 (472 mio. T in 2012) (FEFAC, 2012) ........................................................................................................................................ 108 Figure 87. Development of feed material consumption by the EU compound feed industry in the EU-15 (FEFAC, 2012) ................................................................................................. 109 Figure 88. Feed material consumption by the compound feed industry in 2012 in the EU-27 (FEFAC, 2012) .................................................................................................................. 109 Figure 89. EU-27 dependency in feed proteins (FEFAC, 2012) .............................................. 109 Figure 90: Global soybean production (1961-2014) (FAOSTAT, 2017). ................................. 110 Figure 91: Global share of animal feed production, 2014-2016 (C. Zulauf, 2017). ............... 110 Figure 92: European soybean production 1961-2014 ( (FAOSTAT, 2017). ............................ 111 Figure 93: European soybean imports and exports 1961-2014 (FAOSTAT, 2017). ............... 111 Figure 94: Soybean cake imports and exports 1961-2014 (FAOSTAT, 2017). ....................... 112 Figure 95: European soybean producers 2014 (FAOSTAT, 2017). ......................................... 112 Figure 96: Greek soybean imports and exports 1961-2014 (FAOSTAT, 2017). ..................... 113 Figure 97: Greek soybean meal imports and exports 1961-2014 (FAOSTAT, 2017). ............ 113 Figure 98: Global price of soybean (FRED, 2017). ................................................................. 114 Figure 99 Gross Inland Consumption of primary energy in the EU-28 in 2014 1.605.9 Mtoe (EC, 2016). .............................................................................................................................. 115 Figure 100: Greek energy mix, total consumed 2006-2015 including both domestic and imported sources of energy (Eurostat) ........................................................................... 116 Figure 101: Greek renewable energies consumed in 2006-2015 including both domestic and imported sources of energy (Eurostat) ........................................................................... 116 Figure 102. The three Greek islands connected to mainland electricity grids are highlighted as Samothraki (North-East), Euboea (East of Athens) and Andros (South-East of Euboea). ........................................................................................................................................ 117 Figure 103: Heating degree days of Greece vs EU-28 in 2016 (EuroStat, 2016). .................. 118 Figure 104: Resource share contributing to heating applications in Greece (2010) (Dasyra, 2015). .............................................................................................................................. 118 Figure 105. Total annual average waterfall in Greece (Mimikou, 2003). .............................. 120 Figure 106. Usage of cereals in the EU-27 in 2012-2013 (FEFAC, 2012) ............................... 121 Figure 107. Overview of energy mix consumed in Greece in 2015 (EuroStat) ...................... 123 Figure 108: The proposed pathway for the production of novel biodegradable plant pots. 127 Figure 109: A general scheme for the recovery of potato pulp from a starch manufacturing process. ........................................................................................................................... 128 Figure 110: Example of a conventional plastic plant pot intended for replacement by novel AgroCycle products. ........................................................................................................ 130 9
Deliverable 6.2 Figure 111: Dehydrated potato pulp can be manufactured into pellets for applications in animal feed (Feedipedia, 2016) ...................................................................................... 131 Figure 112: A potential supply chain for the current processing of potato pulp. ................. 132 Figure 113. Market share of EU flower and plant producing nations (EC, 2016). ................. 133 Figure 114: EU 28 and Italian flower and plant production in the period between 2006-2015 (EC, 2016). ....................................................................................................................... 133 Figure 115: Italian import and export trends of potted plants from 2006-2015 (EC, EuropeanCommision, 2016). ........................................................................................... 134 Figure 116: Key European potted plant export markets in 2015 (tonnes, % = share) (EC, EuropeanCommision, 2016). ........................................................................................... 134 Figure 117. Production of ceramic garden pots in the EU (€million) .................................... 135 Figure 118. Consumption of ceramic garden pots in the EU (€million). ............................... 135 Figure 119. Suppliers of ceramic garden pots to the EU (€million) ....................................... 135 Figure 120 Destinations of EU exports of ceramic garden pots (€million) ............................ 135 Figure 121: Buyer requirements for plant pots (CBI, 2014). ................................................. 136 Figure 122: European natural fibre composites market revenue by application (GrandViewResearch, 2016) ........................................................................................... 138 Figure 123: Key regional players in the production of bioplastics in 2015 (IfBB, 2016) ........ 138 Figure 124: Bioplastics production capacities by material type (IfBB, 2016). ....................... 139 Figure 125: Top European potato producers in 2014 (FAOSTAT, Crops, 2017) .................... 139 Figure 126: Trends in Italian potato production from 1960-2014 (FAOSTAT, Crops, 2017). 140 Figure 127: Trends in Italian potato imports and exports (FAOSTAT, 2017). ........................ 140 Figure 128. Percentage of plastic packaging recycled in Italy between 2005-2014 (EuroStat, 2017b). ............................................................................................................................ 142 Figure 129: Total global polyethylene and polypropylene consumption 2015 ..................... 142 Figure 130: Projected average demand annual growth rate for polypropylene (PP) (2015-2020) (ICIS, 2016). ..................................................................................................................... 143 10
Deliverable 6.2
1. Introduction The scope of this report is to characterise the major value chains of Agricultural Wastes, Coproducts and By-products (AWCB), and describe four novel AgroCycle pathways being developed within the project. The report aims to assist the production of full life cycle assessments for these four AgroCycle pathways. It does this by providing descriptions of the technologies under development, potential value chains and markets for novel products, and the effect of displacing systems currently in place. Furthermore, the study evaluates the economic, environmental and social sustainability of the potential novel AgroCycle pathways. This report first quantifies the production of the most abundant AWCBs in Europe and describes their current treatment methods and uses, as a reference scenario for AgroCycle systems to be compared against. The report then focuses on complete value chain descriptions of the four novel AgroCycle pathways, including feedstocks, technology, market opportunities and products displaced. The four pathways have been selected from technologies being developed in AgroCycle Work Packages 2, 3, 4 and 5. Throughout the analyses, sustainability of the novel pathways are considered by describing the impacts of substituting conventional products with novel AgroCycle pathways. Sustainable value chains can have major impacts on society and deliver policy goals through enhancing: economic sustainability by creating added value to grow the economy; social sustainability by creating jobs and facilitating distribution of value; and environmental sustainability by reducing ecological footprints (FAO, 2014). These three pillars of sustainability, that are described throughout, correspond with the life-cycle-assessments that will be carried out in WP6 for each of the four pathways, namely evaluating; economic, environmental and social sustainability. Realising truly sustainable value chains, will help ensure the longevity and robustness of agri-food production systems and supply chains for future generations (read more about sustainable agricultural production systems and value chains in Deliverables 1.3 and 8.5). This study constitutes Deliverable 6.2 of the Work-package 6: Life Cycle Assessment and Life Cycle Costing of the European Union’s Horizon 2020 research and innovation “AGROCYCLE” programme, under grant agreement Nº 690142.
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Deliverable 6.2
2. Current Uses of AWCB in Europe AWCB supply chains in Europe This chapter fully characterises the major Agricultural Wastes, Co-products and By-Products (AWCB) production in Europe and their current most typical treatment methods and uses. This analysis aims to give an overview of the current AWCB value chains, to help the life cycle assessment researchers in WP6 to analyse effects of diverting resources to novel AgroCycle technology pathways described in later chapters. The major agricultural sectors have been grouped due to their similarity of production systems and subsequent uses of AWCB. The sectors have been grouped into livestock, cereals & oil seeds, fruit, and vegetable production, and their corresponding AWCB are described. The major AWCB from these systems were found in AgroCycle WP1 to be livestock manure, cereal straw, fruit pomace and vegetable; pomace, leaves and peels. The current production systems of these AWCBs have been fully characterised in Deliverable 8.2, and the current value chains of these AWCBs were fully characterised in Deliverable 8.3. This chapter gives an overview of the findings from WP1 and WP8, including the typical production, management, products, markets, and value chains of the major AWCB in Europe. For more details please refer to Deliverables: D1.1, D1.2, D8.2, and D8.3.
Production and utilisation of AWCB in the EU overview Over 2.23 billion tonnes of annual EU AWCBs (average/y 2010-2013) have been analysed in AgroCycle, estimated from the major agri-food production sectors. That is an estimated 1.56 billion tonnes of livestock manure, 0.58 billion tonnes of straw, 57 million tonnes of sugar beet pulp, 16.9 million tonnes of fruit pomace, 9.1 million tonnes of vegetable leaves, 4.4 million tonnes of vegetable peel and (Figure 2). However, these were only one selected AWCB from each sector selected, so there is likely to be a lot more AWCBs produced in reality, if considering products not in the project scope. However, the AWCB analysed represent the major AWCB from the biggest crops in the EU. Generally, AWCBs are used for animal feed, energy recovery or as a bio-fertiliser. Otherwise when there is no local demand or drying is not economical, AWCBs are often disposed which causes environmental problems such as leaching of nutrients, emissions and bad smell. Figure 1. Grazing cattle The livestock sector (Figure 1) produces the most AWCB (manure) of those analysed by far, particularly in France and Germany, the biggest producers of livestock in EU28 community (Figure 2). Manures are typically used as biofertilisers or increasingly for energy production. After livestock manure, straw is the next largest resource, produced at significant levels, particularly by France, and also Germany, Poland, Romania, Italy, Spain and the UK. Straw is typically used for animal bedding, fodder, horticulture, as a soil conditioner and increasingly for energy production. 12
Deliverable 6.2 In comparison to straw and manure, fruit and vegetable wastes are produced in much smaller volumes. Significant quantities of fruit are produced and processed in: Spain, France, Italy and Greece, particularly olives and grapes (mainly to olive oil and wine). These countries have good climate conditions for production of fruit and developed technology for fruit processing. Fruit pomace is normally utilised as animal fodder where there is demand, for energy recovery or composted, or otherwise disposed of. Figure 2. Average annual quantities across the EU-28 of all the selected AWCB analysed in this report (20102013).
AWCB analysed: Sugar beet pulp, Vegetable Leaves (cauliflower and cabbage), Vegetable Peel (carrot, potato, onion), Fruit Pomace (grape, tomato, apple, orange, tangerine, peach, olive), Straw (from wheat, barley, oats, triticale, rye, rapeseed, rice, sunflower, stalks, maize), and Manure (from pigs, chicken, cattle, dairy). Data source: AgroCycle Deliverable 1.1, graph source D8.2.
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Deliverable 6.2 Figure 3. Sugar beet The greatest quantities of analysed vegetable AWCBs were by far from sugar beet pulp (Figure 3) (mainly in France, Germany), followed by brassica outer leaves, potato peel, onion and carrot peel. Outer leaves of brassica vegetables (cabbage and cauliflower) are highly produced in Poland and Romania, also Germany and Greece. Vegetable AWCBs have varied uses, but generally are either used for animal feed where available and there is demand, integrated back into the land where uneconomical to collect in field (mostly surplus leaves and crop residues), or disposed of (particular after processing in factories where there is no demand). However, increasing amounts of vegetable AWCBs are being treated via energy recovery technologies such as anaerobic digestion. Overall, the largest producers of analysed AWCB in the EU28 community (annual average production 2010-2014) were the largest EU countries: France (413 million tonnes), followed by Germany (352 million tonnes), Poland (189 million tonnes), the UK (176 million tonnes) and Spain (168 million tonnes) (Figure 2). These countries have large populations and developed agricultural industries. Less populated countries like Malta, Cyprus, Luxembourg, etc. have almost no appearance on figures compared to top producers, but more specific graphs follow in this report and all the data can be found in AgroCycle Deliverable 1.1.
Livestock AWCB During meat production, a wide variety of AWCBs are produced, which range in value and use. There are three stages of AWCB production common for most livestock production systems, as exemplified by the cattle AWCB production map in Figure 4. First during the animal’s life manure is produced daily, this is typically the most abundant waste produced during the value chain, described more in the next section. Next, AWCBs are produced during the slaughtering stage, whereby co-products are separated (Figure 4). Many of the animal co-products, such as leather, bones, and feet are typically sold to markets such as for food, fertiliser, and clothing. Where there is no current market, AWCB such as slaughter house wastewater is treated to comply with waste regulations. However, an increasing amount of animal wastes and by-products are now being used as a feedstock for anaerobic digestion. Finally, AWCB can be produced further down the value chain as rotten meat, which is typically disposed of by retailers or consumers. 14
Deliverable 6.2 Figure 4. Typical cattle AWCB production
Manure production Manure is the most abundant AWCB produced by livestock production, and also the most abundant of all the AWCBs studied in Europe for AgroCycle. Therefore, AgroCycle has focused evaluation of livestock AWCB value chains on the valorisation of manure (Figure 5). Figure 5. Examples of farm yard manure and slurry
Between 2010-2014 Europe produced an estimate 1.56 billion tonnes of manure annually (AgroCycle Deliverable 1.1). France and Germany produced the most manures overall, with 272 million and 255 million tonnes (annual average between 2010-2014) respectively (Figure 6). The other largest producers were the UK (134 million tonnes), Poland (125 million tonnes), Spain (120 million tonnes), Italy (114 million tonnes). Of the livestock sectors anaylsed, beef cattle produced the largest amount of manure in the EU (727 million tonnes), followed by dairy cows (520 million tonnes), and pigs (283 million tonnes) and chickens produced the smallest amount of the analysed manures (31 million tonnes) (Figure 6). 15
Deliverable 6.2 Figure 6. Total quantities of manure analysed across the EU-28
Data source: AgroCycle Deliverable 8.2 and 1.1.
Typical manure management and use Manure is a by-product of all animal growth and is produced daily; including by beef cattle, dairy cattle, pigs, and poultry. Manure is produced year-round, but is stored and used seasonally, unlike crop residues, which are generally only available seasonally. The most common and traditional use of manures and slurries are to spread them back on to land as a bio-fertiliser. The spreading of manures as biofertiliser is constrained due to season, weather conditions, pollution legislation, and biosecurity reasons (to avoid spreading of disease), and must be stored suitably until use. Therefore, the vast majority of livestock farms with indoor livestock already have storage facilities in place for manure, ready for use. Whereas, in less intensive systems, at stages when livestock are outdoors, manure is normally left in field to decompose and act as a biofertilser. 16
Deliverable 6.2 Manure is also increasingly being used for energy and fuel production via anaerobic digestion (AD) and biomass boiler systems. Figure 7 shows a simplified system map of the typical value chains of manure. More detailed manure system maps and value chain descriptions are available in AgroCycle Deliverable 8.2 (manure production) and 8.3 (current manure value chains). Figure 7. Typical current value chain of manure
Later in this report, the full value chain of the micro-scale modular AD facility being developed in work package 2 has been characterized. The aim of developing this advanced AD technology is to increase the exploitation of a mix of AWCBs as feedstocks, particularly the abundant manure resource across Europe.
Cereal and oil seed AWCB Cereals and oil seeds are mainly grown for their grain, to sell into food, feed, and fuel markets. After grain, the primary product, is harvested the stalk and leaves (straw) that remain in the field are the major by-product, representing between 40-400 % of the weight of harvested grain depending on the cereal and yield (Figure 8). In the case of cereals if the grain is then processed into white grain, such as for white rice, bran is removed representing about 10-20% of the grain (Figure 8). The value chains of rice bran are fully characterised in this report, in section 5. WP3: Developing Novel Biofertilisers from Rice Bran. Whereas, for oil seeds, such as oilseed rape and sunflower, straw is still the major by-product, but during processing into oil, there is a cake meal by-product after crushing the seeds representing around 60-74% of the grain.
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Deliverable 6.2 Figure 8. Typical rice AWCB production
Figure 9. Straw bale in field
Production of straw
The major AWCB of cereal and oil seed production is straw, and straw is also the second most abundant of all the AWCBs studied in Europe after manure. Therefore, AgroCycle has focused full characterisation of cereal and oilseed AWCB value chains on the valorisation of straw in WP8 (Figure 9). Of the cereal and oilseed crops analysed for AgroCycle, an estimated 583 million tonnes of straw were produced annually on average between 2010-2013 (Eurostat and D1.1). Wheat and maize straw were the most abundant straw resource, followed by oilseed rape, barley, triticale, sunflower, oat, rice and rye straw. The presence of these cereals across Europe was quite varied. All EU-28 countries grew oilseed rape and twenty-seven countries in the EU grew wheat and oat and barley (except Malta), whereas only eight countries grew rice and fifteen grew sunflowers mainly due to climate. The top producer of rice in Europe was Italy, followed by Spain, Greece, Portugal, France, Romania, Bulgaria, and Hungary (Figure 10). France was the top producer of straw, particularly of wheat and maize. Germany are the next biggest producers of straw, mainly wheat and barley. Poland’s production of straw is largely oilseed rape, wheat and triticale, and Romania is dominated by maize and wheat. The UK also have a large production of straw, mainly wheat and oilseed rape. All EU 28 countries can be seen in Figure 10. For a further breakdown of straw production see AgroCycle D1.1. or D6.2. 18
Deliverable 6.2 Figure 10. Annual average quantities of straw analysed across the EU-28 (2010-2013)
Data source: AgroCycle Deliverable 8.2 and 1.1.
Typical straw management and use Depending on the management system, straw can be harvested after drying in the field, baled and then used on farm or sold to livestock and other agricultural markets. Otherwise if there is no on-farm use or local market, straw is often left in the field and incorporated back into the land, typically after being chopped into smaller pieces to aid break down in the soil. Straw consists mainly of dry, lingo-cellulosic biomass and nutrients. 19
Deliverable 6.2 Straw is currently used for many applications, but it is mainly used for animal and crop production systems, requiring little or no processing. The majority of utilized straw goes to animal bedding, particularly for horses and cattle. Other typical uses of straw include as a fodder for livestock, soil conditioner to improve soil carbon, protection for arable and fruit crops over winter and mushroom compost. However, there is an increasing amount of straw being used as feedstock for energy production via incineration or anaerobic digestion across Europe, including in Denmark and the UK. shows a simplified system map of the typical value chains of straw. More detailed straw system maps and value chain descriptions are available in AgroCycle Deliverable 8.2 (production) and 8.3 (current value chains). Straw can also be seen as potential feedstock for the technology developed in WP2, the micro modular-AD system. Figure 11. System map of typical straw value chains
Fruit AWCB During the production of fruit, there are many stages where AWCB are generated. First, during cultivation and harvesting, the main AWCBs are pruning residues and leaves from the trees or stalks the fruit grows on. Fruit is then either sold as food or processed into many products, including fruit juices and sauces (Figure 12). In the value chain of fruit to be consumed as solid fruit, a large proportion is thrown away by agriculture, retail and consumers, due to reasons such as rotting or cosmetic features. Wastewater is a major by-product of cleaning fruit before sale or processing. The wastewater value chain from fruit processing are fully characterized in this report in section 6. WP4: 20
Deliverable 6.2 Development of a Novel Wastewater Treatment Facility. In the next step in the value chain of processing fruit into juice, the major AWCB stream generated is fruit pomace. Fruit pomace is a by-product of pressing raw fruits Figure 12, after removing its juice or oil content. Fruit pomace contains the skin, pulp, seeds and stems of the fruit, which comprises around 25%35% of the mass of the fresh fruit (Kruczek, 2016). Figure 12. Typical fruit processing schematic
The remainder of this section will describe fruit processing and production of pomace, as the major by-product of fruit production described in AgroCycle WP8 (see Deliverable 8.2 and 8.3), and indication of countries and fruit processing sectors to target AgroCycle wastewater technology.
Fruit production and processing As estimated in WP1, over 74 million tonnes of fruit analysed (apples, grapes, oranges, tangerines, peaches, tomatoes and olives) are produced every year in the EU (average 20102015). The most harvested fruits in the EU are grapes (over 24 million tonnes annually) and tomatoes (16 million tonnes), followed by apples (12 million tonnes), olives (10 million tonnes), oranges (6 million tonnes), tangerines (3 million tonnes), and peaches (3 million tonnes). The country harvesting most fruit is Spain (23 million tonnes), followed by Italy (21 million tonnes), France (9 million tonnes), Greece (5 million tonnes), Poland and Romania (both over 3 million tonnes) (Figure 13). 21
Deliverable 6.2 Figure 13. Average tonnes of fruit harvested across the EU annually (2010-2015)
Data source: AgroCycle Deliverable 8.2 and 1.1.
Of these fruits, almost 57 million tonnes are processed every year in the EU into products like juice, wine, olive oil and sauces, where ultimately AWCB are generated. The most prevalent AWCB is fruit pomace (left over solid). Of the fruits analysed by AgroCycle, an estimated 17 million tonnes of fruit pomace are produced every year in the EU. Olives and grapes were the most processed fruits in the EU, with 6.4 million and 4.8 million tonnes of pomace produced annually respectively (2010-2013), mainly concentrated around the southern European states of Spain, Italy and Greece. Citrus is next biggest resource of pomace (1.6 million tonnes of orange solids and 856 thousand tonnes tangerine pomace), followed by tomato (1.9 million tonnes), apple (over 1 million tonnes annually), and peach (290 thousand tonnes).
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Deliverable 6.2 Figure 14. Average tonnes of fruit processed across the EU annually (2010-2013)
Data source: AgroCycle Deliverable 8.2 and 1.1.
Typical fruit pomace management and use
Figure 15. Apple pomace
Due to the high content of moisture and biodegradable compounds, fruit pomace can be spoiled unless it is quickly utilised, ensiled, or dried prior to its storage. Dried pomaces can be transported all over the world (Figure 15). However, unless sun drying is available, drying can be an energy intensive and expensive procedure. Fruit pomaces are mainly used wet in various applications, particularly as animal feed near to the factory. Niche applications of fruit pomaces gain higher value, such as extracts for nutraceutical markets, specialty alcohols and essential oils, and biocomposites. Low value fruit pomace with no local market, is increasingly 23
Deliverable 6.2 being fed into AD or composted into bio-fertiliser, otherwise it is sometimes discarded in open areas potentially causing environmental problems due to soil and groundwater pollution. For a summary of current uses see Figure 16, and for more detail see AgroCycle Deliverable 8.3. Figure 16. System map of typical fruit pomace value chains
Vegetable AWCB A diverse range of vegetables are grown, processed and supplied across Europe, and due to the varied nature of their production cycles, appearance, harvesting techniques and seasonality waste and residues arising from their production are equally varied. AgroCycle have identified the main AWCBs produced from vegetables in Europe, are from sugar beet, excess outer leaves from cabbage and cauliflower, and peel and pulp (carrot, potato, and onion). Vegetable AWCBs also arise during harvesting, supply chains and in homes, due to damage, rotting and over production. In addition, other residues arise during processing, such as wastewater (described more later in this report), and suspended solids. For example, see the typical AWCBs produced during potato production and processing in Figure 17. 24
Deliverable 6.2 Figure 17. Typical potato skin AWCB production
Production of vegetable AWCBs The greatest quantities of analysed vegetable AWCBs in the EU-28 (average annual production 2010-2013), were by far from sugar beet pulp (Figure 18). Around 57 million tonnes are produced every year, mainly in France, Germany, Poland, UK, and the Netherlands. This could increase soon as quotas for sugar beet, limiting the amount grown in the EU, are to be lifted. Brassica outer leaves were the next largest AWCB resource analysed. Annually there are around 7.2 million tonnes of cabbage outer leaves, predominately in Poland and Romania, and 1.9 million tonnes of cauliflower and brocili outer leaves (2010-2013 annual average). Potato peel is next largest vegetable AWCB resource (over 3 million tonnes), and there was almost 1 million tonnes of onion peel, and 370 thousand tonnes of carrot peel (annual averages 2010-2013) (Figure 19). Large quantities of potato and carrot peel can be found in Poland, Germany, Belgium and the UK. Onion peel is less widely generated, but significant quantities appeared in Netherlands, Spain and Poland. Figure 18. Average annual quantities of analysed sugar beet pulp across the EU-28 (2010-2013)
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Deliverable 6.2 Data source: AgroCycle Deliverable 8.2 and 1.1. Figure 19. Average annual quantities of analysed vegetable peels and leaves across the EU-28 (2010-2013)
Data source: AgroCycle Deliverable 8.2 and 1.1.
Typical vegetable AWCB management and uses The use of peel depends on the vegetable it comes from, as their properties are quite distinct. For instance, brassica leaves and sugar beet pulp are commonly used as animal feed, and carrot and potato peel can also be fed to animals. However, potato peel can only be fed to ruminant animals, due to the extra digestion required to break down fiber. Brassica leaves are also fed to animals with caution, as too much can cause bloating and problems health. Whereas onion skins are not suitable for fodder due to their aroma. Peelings and sugar beet pulp can also be valorised as food ingredients, dried nutraceutical extracts and powders. Alternatively, vegetable leaves, peels, and sugar beet pulp are composted or processed using anaerobic digestion (AD). However, even though there are technologies, patents and applications available or under development (detailed in Deliverables 1.2 and 8.3), large volumes of peelings are discarded in many cases. 26
Deliverable 6.2 An overview of the typical current management of analysed vegetable AWCBs are presented in the system map below (Figure 20). These value chains are described in more detail in Deliverable 8.2 and 8.3. Figure 20. System map of typical vegetable AWCB value chains
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Deliverable 6.2
3. AgroCycle Pathways Overview The following chapters will give an overview of the selected AgroCycle pathways for case study. These case studies are fully characterised, to showcase the novel technologies and novel pathways, to assist life cycle analyses to be conducted in WP6. They describe the novel pathway, including feedstocks required, logistics, valorisation and products, followed by the current uses of the feedstocks required, potential markets for products and markets displaced by the novel pathway. Brief overviews of each case study are summarised below. WP2 Case Study: Small Scale Anaerobic Digestion (AD) Facility Processing Mixed AWCB The case study representing work package 2 is about small-scale AD to treat mixed farm AWCB. The majority of AD capacity in the UK comes from large scale AD facilities, where developers can benefit from economies of scale, to invest in all the equipment and logistics required. However, smaller scale AD has not developed as fast, as it is harder to justify investing large amounts of capital on new equipment. Being without AD disproportionately impacts small and medium farms economically, socially and environmentally, as AWCB do not get used to their full potential, generate power or create the extra jobs in rural communities. Experimental work within AgroCycle will test a variety of AWCBs to be treated using AD, to help producers understand the potential use of mixed AWCB feedstocks at different scales. The corresponding life cycle analysis will investigate economic, social and environmental impacts of operating at different scales of AD, to understand the potential impact of rolling out AD to more small and medium farms across the UK. This case study focuses on AD in the UK to allow for a more in-depth analysis of any system change. WP3 Case Study: Developing Novel Biofertilisers from Rice Bran The second case study will address the aims set out in work package 3 to develop novel biofertilizers from AWCB materials as investigated by researchers at the Demeter Cereal Institute (Thessaloniki, Greece). In particular, this case study involves the valorization of cereal AWCB, primarily brans obtained from rice production. The proposed pathway competes with the use of synthetic fertilizers by generating rice bran composts for future crop enrichment. The ultimate goal is to promote a circular rice cultivating process whereby dependence on chemical fertilizers is reduced to create a more sustainable production system, and the higher quality rice product can be marketed as organic and gain higher value compared to cheap imports. WP4 Case Study: The case study from work package 4 addresses the treatment and valorization of wastewater generated during fruit washing and processing, being development at the Centre for Research and Technology-Hellas (CERTH) (Thessaloniki, Greece). Peach, apple, kiwi and pear wastewaters will be valorized in this three-stage modular process. The first treatment stage will be to valorise the fruit AWCB biomass to generate single cell proteins to enter food and feed protein markets. An anaerobic digestion stage will follow, aiming to reduce pathogen content and to valorize residual organic matter within water to produce a valuable biogas coproduct to power the fruit processing operations. Finally, an advanced filtration step will be employed for upgrading the end quality of effluents, ensuring waters are safe to reuse in a number of applications. The key aim of this system is to demonstrate that better value can be
28
Deliverable 6.2 obtained and that further waste reduction is achievable compared with current wastewater treatment techniques. WP5 Case Study: Developing Novel Biocomposites from Potato Pulp The final case study from work package 5 aims to valorise potato pulp fibers for the development of novel biocomposites. It is intended that their end application will be in the production of biodegradable plant pots. Conventional plastic pots raise a number of waste related concerns as they are not biodegradable, can cause plastic pollution in agriculture and gardens, and are typically disposed of after use, with the majority resulting in landfill. It is hoped that the novel products introduced here will address such problems in addition to valorising AWCBs from the starch manufacturing industry. The development of this AgroCycle technology is being carried out at CNR-IPCF (Italy) and Fraunhofer (Germany). 29
Deliverable 6.2
4. WP2: Small Scale AD Facility Processing Mixed AWCB The primary objective of work package 2 is to demonstrate the technical feasibility of the production of biofuels from AWCB. As the selected technology from WP2 for the WP6 sustainability analysis, the following section of this report will focus on wet anaerobic digestion (AD), fed on mixed AWCB. The majority of AD capacity in the UK comes from large scale AD facilities, where developers can benefit from economies of scale, to invest in all the equipment and logistics required. However, smaller scale AD has not developed as fast, as it is harder to justify investing large amounts of capital on new equipment. Being without AD disproportionately impacts small and medium farms economically, socially and environmentally, as AWCB do not get used to their full potential, generate power or create the extra jobs in rural communities. Experimental work within AgroCycle will test a variety of AWCBs to be treated using AD, to help producers understand the potential use of mixed AWCB feedstocks at different scales. The corresponding life cycle analysis will investigate economic, social and environmental impacts of operating at different scales of AD, to understand the potential impact of rolling out AD to more small and medium farms across the UK. Experimental work is being carried out in the UK and so this case study will focus research on the UK only, to allow for a thorough and focused LCA to be conducted later in the project. This case study describes the feedstocks, supply chains, markets and policies which need to be considered for the expansion of mixed AWCB wet-AD. This will help provide information for a comprehensive sustainability analysis and discussion to draw conclusions on whether the valorisation pathway outlined is beneficial from the perspective of the three pillars of sustainability (environment; social; economic), when compared against business-as-usual scenarios.
Novel Pathway Description Summary of Pathway Anaerobic Digestion (AD) is the biological treatment of plant or animal derived biomass, in sealed containers, in the absence of oxygen. ‘Wet’ AD systems typically process materials with DM content between 5-15% (e.g. cattle slurry and pig manure and food waste) and are increasingly being deployed across the UK (NNFCC, 2017). A variety of AWCB such as manure and crop residues will be mixed and fed through wet-AD systems by AgroCycle researchers. The products of AD are biogas and digestate. Biogas is a mix of typically 60% methane and 40% carbon dioxide which can be burned to generate heat and/or power, or cleaned to produce pure biomethane for injection into the national gas network or use as vehicle fuel. Digestate is a nutrient rich organic fertiliser, with valuable properties for agriculture,
30
Deliverable 6.2 horticulture or amenity use. The typical value chain is shown in the schematic below, from inputting feedstocks to energy outputs and digestate fertiliser (Figure 21). Figure 21. Schematic of typical anaerobic digestion value chains
AD Pathway Feedstocks AgroCycle experiments will test a range of AWCBs (e.g. manures and crop residues) will to be valorised using wet AD technology (NNFCC, AD, 2017). Wet feedstocks may be pumped and stirred during AD processing, unlike drier feedstocks which are typically stacked and stirred with greater difficulty. The treatment of feedstocks will also incorporate a mixing/chopping stage prior to dry AD to eliminate the formation of layers caused by varying particle sizes and to ensure that biogas yields are enhanced. Currently in the UK, the majority of AD feedstocks originate from AWCBs in the agri-food supply chain; from field to post-consumer food waste. According to NNFCC’s annual “AD Deployment in the UK report 2017”, at the start of 2017 there were 401 operational AD plants in the United Kingdom. Of these, 277 were mostly farm-fed (over 50% manure; slurry; energy crops; crop AWCBs) with a total installed capacity of 160.1MWe, and 124 of which were mostly waste-fed (over 50% municipal, commercial and industrial food wastes) with a total installed capacity of 203.1MWe (NNFCC, 2017). These operational AD plants cumulatively required 10,167,272 tonnes of feedstock, consisting of (Figure 22); • • • •
•
3,181,000 million tonnes per annum (tpa) of food waste (waste food from municipal solid waste, commercial and industrial waste). 2,025,000tpa of ‘other’ (mainly green AWCBs, industrial AWCBs (e.g. brewery effluent) and processing residues). 425,000tpa of crop AWCBs (residues (e.g. apple pomace, straw) and wastes (e.g. vegetable outgrades) 3,370,000tpa of dedicated energy crops (including maize, grass silage, whole crop cereals and sugar beet). The estimated cropping area required by operational AD plants in the United Kingdom is 75,000 hectares. 1,487,000 tpa of farm yard manures (FYM) and slurries.
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Deliverable 6.2 Figure 22: Growth of AD feedstocks used throughout the UK*
*Estimated values of feedstocks actually deployed up to 2016 (solid line), and future projections past 2017 (dotted line) based on the assumption that 100% of projects that currently have planning permission will go through to completion. In reality, around 50% of future projects are predicted to go through to completion; success very much depends on developers securing finance and feedstocks, and the policy environment. Data source (NNFCC, 2017).
The volume of FYM processed by AD doubled between 2015-2016, but grew more slowly over the past year (from 1.2 to 1.5 million tpa; an increase of just 300,000 tpa in 2016-2017) (NNFCC, 2017). However, there is an estimated 90 million tonnes of manure produced annually in the UK. This represents a huge opportunity for the novel AgroCycle system as there is a clear surplus of AD feedstocks available which are not yet being valorised to their full potential. There is likely to be sufficient manure feedstocks despite competition for these materials predicted to rise over the next year. There are 420 additional AD facilities in the development pipeline in the UK, 390 of which are expected to be farm-fed. AD projects under development in the United Kingdom are anticipated to cumulatively require 1,800,000tpa of manure or slurry, 2,757,000tpa of crops, 2,610,000tpa of food waste, 258,000tpa of crop AWCBs and 1,631,000tpa of other AWCB feedstocks. This growth in feedstock use is illustrated in Figure 22. The further expansion of AD systems across farms in the UK could increase the treatment of a wider range of AWCBs generated. AWCBs i.e. manures, slurries and crop AWCBs, will have the opportunity to be more suitably valorised, in addition to other organic materials recoverable on industrial and farm sites. From farms rearing animals for food production, the main waste material is the generation of manure (see section 2 ‘Current uses of AWCB’, for more information on animal waste generation) which is typically collected and stored in indoor rearing systems. Manure is therefore a highly available feedstock for use in novel AD systems. For example, it is estimated that manure represents around 88% of the total AWCB generated by poultry birds and 99% of cattle AWCB (AgroCycle Deliverable 1.1).
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Deliverable 6.2 However, manures currently have relatively low biogas yield (15-100 m3/t), when compared with other feedstocks such as crops, grass and food waste (200-700 m3/t) (Table 1). Potential reasons are that materials are already partly digested in animal digestive systems, and straw mixed with manures can slow down the reaction and cause problems in the AD systems. Currently AD facilities often mix feedstocks, adding crops to manures, to obtain higher biogas yields. However technological advancements could help increase these yields without necessarily demanding that feedstocks are mixed (NNFCC, 2017). Table 1: Typical biogas yields available from different types of biomass (NNFCC, Feedstocks, 2017).
FEEDSTOCK
BIOGAS YIELD (m3/t)
FEEDSTOCK
BIOGAS YIELD (m3/t)
Cattle slurry
15-25
Potatoes
276-400
Pig slurry
15-25
Rye grain
283-492
Poultry
30-100
Clover grass
290-390
Grass silage
160-200
Sorghum
295-372
Whole wheat crop
185
Grass
298-467
Maize silage Maize grain
200-220 560
Red clover Jerusalem artichoke
300-350 300-370
Crude glycerine
580-1000
Turnip
314
Wheat grain
610
Rhubarb
320-490
Rape meal
620
Triticale
337-555
Fats
up to 1200
Oilseed rape
340-340
Nettle
120-420
Canary grass
340-430
Sunflower
154-400
Alfalfa
340-500
Miscanthus
179-218
Clover
345-350
Flax
212
Barley
353-658
Sudan grass
213-303
Hemp
355-409
Sugar beet
236-381
Wheat grain
384-426
Kale
240-334
Peas
390
Straw
242-324
Ryegrass
390-410
Oats grain
250-295
Leaves
417-453
Chaff
270-316
Fodder beet
160-180
Farms cultivating food crops also generate notable quantities of spoiled/unused edible wastes and inedible plant fractions i.e. stalks, leaves, protective husks etc. (see section 2 ‘Current uses of AWCB’, for feedstock availability), which are suitable feedstocks for an AD plant. Production of these feedstocks are confined primarily to times of harvest, compared to animal manures that are generated daily and typically all year-round. Hence, FYMs are more consistent feedstocks, but as mentioned previously, mixing feedstocks can often result in better gas yields, and so these seasonal feedstocks could be included when available to boost system outputs.
AD Pathway Logistics When describing the pathway of a novel technology, it is important to consider the logistical requirements of the system. In this case, the logistics will address feedstock collection, feedstock storage and transportation of the materials.
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Deliverable 6.2 4.1.3.1 Farm Waste Collection Ease of FYM collection will ultimately depend on where the manure is produced. If contained within a livestock/poultry shed or shelter, the distribution of manure will be limited and is typically collected already, minimising additional efforts to collect the feedstock. If, however, manure is deposited in open fields, typically it will not be collected, and is therefore not easily available for valorisation. Instead, these waste materials will act as valuable soil enhancers at the locations they are deposited (E. White, Report on the holistic analysis of AWCB chains and logistics of AWCB valorisation systems, 2016). Crop residues left in the field are also typically more difficult to gather. Due to the widespread adoption of combine harvesters throughout the UK, straw residues generated after harvest are often spread across fields. Manual collection is therefore an unfeasible option, indicating that heavy machinery (e.g. straw baler) is essential for the collection of these AWCBs as feedstocks for AD (H. Nguyen, 2016). Crop residues can be collected and made available as feed for animals and are therefore deposited as farm yard manures. Furthermore, crop AWCBs generated in factories, (i.e. potato skins and excess leaves), are already collected and often require payment to dispose of. These factory wastes and AWCBs used for other purposes (e.g. animal feed), are much more available than crop residues left in fields after harvest (read more in AgroCycle Deliverable 8.2 about production and availability of AWCBs). Dry matter (DM) content of AWCBs is another factor influencing the collection of AD feedstocks. Table 2 highlights the dry matter content of key feedstocks available for AD. A simple method for collecting more liquid FYM (e.g. pig/beef cattle slurry) is to arrange a slotted/perforated floor, that animals can stand on, over a collection vessel. Excreted manure will fall through openings in the floor and accumulate in the tank below. Minimal labour is required making it a highly favourable collection method. However, for manures containing considerably more solids (e.g. poultry litter), this method is less effective as the likelihood of blockages increases. Scraping is another common collection technique, used to gather FYM deposited in alleys/gutters. Waste is then moved to a pit or tank with help from a tractor mounted scraper or by using a fully automated system (C. Fulhage, 2017). Read more about the collection and availability of AWCBs in AgroCycle Deliverable 8.2. Table 2: Dry matter content of typical AD feedstocks (NNFCC, 2017). Feedstock Dry matter
Pig slurry 8%
Cattle slurry
Poultry manure
Grass silage
10%
20%
28%
Whole wheat
Maize silage
Maize grain
Crude glycerine
Wheat grain
Rape meal
33%
33%
80%
80%
85%
90%
4.1.3.2 Farm Waste Storage The storage of agricultural wastes is often an unavoidable stage in the logistical process. For animal manures, where production is constant and application as a fertiliser is seasonal, waste accumulation is inevitable and often required until it is safe to use. Therefore, FYM must either be moved to an intermediate storage facility or directly to the site of end use (E. White, Report on the holistic analysis of AWCB chains and logistics of AWCB valorisation systems, 2016). AD technology is capable of processing manure wastes soon after they are generated, consequently minimising storage requirements. However, depending on farm size and quantity of feedstocks produced, AD facilities may be unable to process all FYM immediately. Hence, manure storage may still be necessary in these cases. Solid animal manures can be stored in containers or stacked under a roofed building, on a waterproof base or temporarily in a field, as long as liquids are not leaked to the surrounding environment (DEFRA, 2017). Slurries however, are generally collected and stored in special anti-corrosive tanks or 34
Deliverable 6.2 reception pits, typically fitted with drainage pipes to transfer mixtures elsewhere (DEFRA E. A., 2017). If storage is unavailable onsite, excess manures can be transported to offsite holding facilities or otherwise traded for biofertiliser applications. For similar reasons, the storage of crop AWCBs may also be necessary. Since straw baling is a common collection method for this type of feedstock, storage in bale form is an easy and convenient solution to this problem. Bales can be stored indoors or outdoors, with a level area of hard-standing and easy access being the only essential requirements. Alternatively, ensiling; the anaerobic storage of materials in silos or clamps, is another popular method of storing AWCBs of this nature as feedstocks for AD. 4.1.3.3 Farm Waste Transport Traditionally, feedstock transport is considered the most expensive and energy intensive aspect of AWCB treatment; particularly for wetter feedstocks. Therefore, it is essential to centrally collate feedstocks from the point of collection to the AD facility itself. Vacuum collection can be used to draw a variety of feedstocks from the point of production directly to the AD system. Alternatively, pumps, specially designed to handle thick fluids (e.g. animal manures), can be employed to transfer material from collection tanks to the on-site digester. If pumping thicker, more solid feedstocks (e.g. various crop AWCBs) proves ineffective, manual deposition using farm loading equipment can instead be used (C. Fulhage, 2017).
AD Pathway Products 4.1.4.1 Digestate Digestates produced in AD processes can be either spread on land immediately or stored/composted prior to land application. Digestate accounts for around 90-95% of all AD input material, consisting primarily of leftover, indigestible material and dead microorganisms. Due to the biological breakdown of biomass during AD, essential nitrogen, phosphorous and potassium containing compounds within feedstocks become more readily available to plants and soils. Fertilising capacity is therefore significantly improved in comparison with undigested manures/slurries and composts. Digestates however, can only be spread as fertilisers at specific times of the year, due to land-spreading restrictions in place to minimise environmental risk, thus their storage or trading is encouraged to avoid the spoiling and potential waste of these materials (NNFCC, 2017). Typical digestates are composed of solid and liquid fractions, both of which display favourable fertiliser properties. However, since the transportation of solids is more efficient than liquids, the separation of phases is often preferable. Separated fibres are better soil conditioners but liquors (DM 97% can be recovered, due to removal of CO2 from the biogas (Zafar, 2016). Biomethane exhibits an energy density almost twice that of biogas and therefore represents a highly-coveted output of the novel AD system. Figure 24 illustrates a general overview of the processes responsible for conventional AD system outputs (PlanET, 2017). Figure 23: Pressure swing adsorption facility schematic highlighting how CH4 can be produced after treatment with the AD facility. Figure adapted from (Zafar, 2016).
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Deliverable 6.2
Figure 24: Overview of the products and processes occurring within a general anaerobic digestion system (PlanET, 2017).
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Deliverable 6.2
Current Supply Chains of AD Pathway Feedstocks: Manure The expansion of mixed-AWCB AD may have positive or unintended consequences by displacing feedstocks from their current management regimes and value chains. These alternative uses of AWCBs will be analysed here. Although the proposed AD technology intends to valorise a wide mix of AWCBs, the primary feedstocks under investigation in this specific AgroCycle case study are manures generated extensively across working farms in the UK, as these are produced most frequently and in the highest quantities compared with all other AWCB. For more information on other feedstock value chains, of straw, vegetable leaves and peel and fruit pomace, see Deliverable 8.3. Figure 25 outlines the average annual quantities of the main animal AWCB generated from poultry, pigs, cattle and dairy cows throughout the UK (AgroCycle Deliverable 1.1). Existing supply chains for other crop AWCBs will be discussed in later points of this report. Figure 25: Average annual UK animal AWCB production for poultry, pigs, cattle and dairy cows. Data source: (AgroCycle Deliverable 1.1)
90 80 70 (Million tonnes)
60 50
Manure Slaughter Waste Food Production Waste
40 30 20 10 0 Chickens
Pigs
Cattle
Dairy Cow
Fertiliser Applications of FYM At present, the vast majority of animal manure is spread on land as a valuable source of organic matter and plant nutrients. Manures provide a slow release fertilisation of the soil and addition of much needed organic matter (Table 5). Although utilisation of FYM as a fertiliser is widely encouraged to reduce dependence on synthetic alternatives and to minimise FYM accumulation, the careful management of these materials is essential. Excess nutrients, greenhouse gas emissions, and harmful microbial levels from manures can be damaging to the environment and counterproductive to crop growth. Of particular concern are forms of nitrogen, which are lost most readily to their surroundings compared with other plant nutrients due to weaker binding capacity with soils. For example, nitrogen is the most commonly lost through the emission of gaseous compounds (e.g. NH3, NO2 and N2) to the atmosphere and by the leaching of dissolved nitrates in the ground 38
Deliverable 6.2 (Nielsen, 2006). In 1991, the European Commission introduced the EU’s Nitrates Directive, setting nitrate spreading limits at 170-250 kg/ha and restricting spreading to certain periods of the year, in an attempt to protect water quality across the region (EuropeanCommision, Nitrates Directive, 1991). Nitrate pollution can lead to algal bloom in waterways thus making drinking water, fisheries and recreational areas unsuitable for use. Nitrate Vulnerable Zones (NVZ) were later implemented throughout the UK following pressure from Europe, imposing further limits on areas at risk of agricultural pollution. The regulations outline specific nitrate limits set by the UK government in 2017 for different crop types within NVZs. It is estimated that around 58% of land in England falls within these designated areas (DEFRA, 2015). Table 4: Nitrate limits for various compounds within NVZs in the UK (2017) (DEFRA, 2017).
CROP N-MAX LIMIT (KG/HA OF N) Autumn/Early Winter-Sown Wheat 220 Spring-Sown Wheat 180 Winter Barley 180 Spring Barley 150 Winter Oilseed Rape 250 Sugar Beet 120 Potatoes 270 Forage Maize 150 Field Beans 0 Peas 0 Grass 300 Asparagus/Carrots/Radishes/Swedes 180 However, digestates from AD also have a high concentration of available nitrogen, and farmers must also be careful with when and where they can spread. Responsible spreading practices of digestate and manures are outlined in guidelines in AHDB’s Nutrient Management Guide RB209. AHDB recommendations to reduce nutrient run-off include applying organic manures in spring, avoiding times when rain is forecast and avoiding spreading near water courses and on steep slopes (AHDB, 2017). To comply with EU and UK government regulation, it is useful to be aware of the nutrient content within specific manures and slurries before land spreading. Table 5 highlights the standard nutrient values different manure/slurries can expect to contain. This table should be used as a reference, so FYM can be applied to crops accordingly, ensuring maximum limits are not exceeded.
39
Deliverable 6.2 Table 5: Typical amounts of nitrogen, phosphate, potash, sulphur and magnesium contained in fresh weights of manures (DEFRA, 2010).
Furthermore, livestock producers must take responsibility in limiting pathogen spread from FYM to the natural environment, food crops, humans and other animals. Good management practices (i.e. animal vaccinations, temperature and ventilation regulation, on-farm sanitation and careful control of runoff liquids) will help to minimise the spread of disease. However, perhaps the cheapest and most widely used method of preparing manures for fertiliser applications is through pre-storage for a given length of time. In the UK, government guidance suggests that solid manures should be stacked for a period of 2 months (3 months for slurry storage) before these materials are deemed safe for use as biofertilisers (DEFRA, 2017). Storage not only helps to reduce pathogen content, but due to regulations which limit the quantity and time of year manures can be spread, it also ensures that manures are not wasted or disposed of when not needed. Manure storage facilities in the UK are currently either anaerobic or aerobic systems. In the former, manure is not exposed to oxygen, creating conditions whereby a large portion of pathogens are unable to survive. Significant pathogen reduction can occur within 30 days with remaining bacteria subsequently destroyed by UV exposure and natural drying during eventual land spreading. Alternatively, aerobic storage methods (i.e. composting) work by treating manures in the presence of oxygen and microorganisms to generate CO2, H2O and heat, at temperatures (65°C) sufficient enough for significant pathogen reduction. If the right conditions are met (e.g. ideal C:N content), an organically rich, safe to use compost is produced with high soil amendment qualities (DEFRA, 2014).
Bioenergy Applications of FYM More recently, livestock manures have shown growing potential for the generation of energy. It is becoming more common to use manures for combustion to generate energy in the form of heat and/or electricity in incinerators or power plants. Combustion is more effective for materials with high dry matter (DM) content as energy requirements are reduced when removing water from the biomass. Chicken litter is therefore more favourably combusted compared with pig slurry, when generating heat for energy applications (E. White, Report on the holistic analysis of AWCB chains and logistics of AWCB valorisation systems, 2016).
40
Deliverable 6.2 There are also more advanced technologies being developed and deployed to extract energy from manures. For example, technologies such as pyrolysis and gasification, although limited at present, show promise in generating energy dense biogases, chemically rich bio-oils and biochar residues with favourable fertiliser properties. A diagram reviewing the pathways of current FYM supply chains is summarized in Figure 26. This is a useful reference point to consider potentially competing systems during the introduction of AD facilities across farms in the UK.
41
Deliverable 6.2
Figure 26: Pathways overview for existing animal manures/slurry supply chains in the UK. Components outlined in red highlight the primary outputs of the existing systems.
42
Deliverable 6.2
Potential Markets for Novel AgroCycle Products A key goal of this report is to highlight the potential of AgroCycle products entering commodity markets. The following analysis describes the commercialisation potential of the novel AD system currently being developed.
UK AD Market Size The anaerobic digestion industry has experienced rapid growth in recent years. In January 2017, there were 401 operational AD facilities in the UK (Figure 27), an increase of 85 facilities in the last year, indicating steady progress in this sector. AD plants can be categorised primarily as agricultural, using predominantly farm derived feedstocks (e.g. manures, slurries, crops and crop residues) or waste fed (e.g. municipal, commercial and industrial residues). Of the 401 AD facilities throughout the UK in 2017, 277 were farm fed (installed capacity of 160.1MWe) and 124 were waste fed (installed capacity of 203.1MWe) (NNFCC, 2017). Despite over double the number of farm fed AD systems online, the operational capacity of waste fed plants was in fact higher, indicating that agricultural systems were in general, used on a smaller scale. Figure 27: Map of all AD projects within the UK (2017) (NNFCC, 2017).
43
Deliverable 6.2 The deployment of all scales of AD facility are projected to continue to rise in the coming years, with 420 plants in the development pipeline; 119 of these are small scale (installed capacity of 20.2MWe), 142 are medium scale plants (installed capacity of 69MWe) and 110 are large scale plants (installed capacity of 202.4MWe) (Figure 28). However, the completion of these projects very much depends on developers securing finance and feedstocks, and a favourable policy environment providing incentives for biogas producers. It is common for about 50% of project to fail before completion. Figure 28. Number of AD plants (diamonds) and installed capacity (bars) by size of plant*
*Actual deployment up to 2016 (solid bars/diamonds), and future projections past 2017 (faint bars/diamonds) based on the assumption that 100% of projects will go through to completion that currently have planning permission. In reality, around 50% of future projects are predicted not to go through to completion; depending on finance, feedstock security, and the policy environment. Data source (NNFCC, 2017).
Of the two main practices to valorise biogas. CHP facilities at present are most abundant on biogas plants throughout the UK with 324 currently under operation and a total installed capacity of 243.1MWe. These plants work by combusting biogas onsite to generate energy (either heat, power or both) which can be fed back to the AD facility to create a self-sustaining process or distributed to nearby buildings or power stations. Of these CHP facilities, 89 were operational on a small-scale (14MWe generating capacity), 118 on a medium-scale (57.3MWe generating capacity) and a further 11 on a larger-scale (220.1MWe generating capacity). The majority of all CHP classified plants were used to produce both heat and power for bioenergy applications, with only 6 in total around the country used to generate heat or cooking gas exclusively (NNFCC, 2017). The second and currently less widespread option is biomethane to grid (BtG) plants that work by upgrading recovered biogas to high purity methane (as discussed in section 4.1.4), offering the potential for gas injection into national grid networks, or the conversion to liquid fuels. Of the 401 AD plants currently in the UK in 2017, 77 were recorded as BtG with an installed electrical capacity of 71.7MWe and a biomethane installed capacity of 45,000 Nm3/hr. The lower number of biomethane facilities compared to CHP can be attributed to the relative immaturity and resultant added expense of biogas upgrading, thus limiting BtG deployment 44
Deliverable 6.2 nationwide. However, recent policy changes have made biomethane projects more economically viable, and CHP less so, with the aim of increasing the deployment of biomethane for the heat (via the gas grid) or fuels. Indeed, biomethane deployment has been expanding rapidly in the past 4 years, and is set to continue. A further 43 biomethane facilities are in development, with a cumulative installed electrical capacity of 29.5MWe and a biomethane installed capacity of 22,000 Nm3/hr. Figure 29 demonstrates the growth in deployment of BtG facilities across the country (NNFCC, 2017). Figure 29. Deployment of biomethane facilities in the UK and installed capacity
*Actual deployment up to 2016 (solid bars/diamonds), and future projections past 2017 (faint bars/diamonds) based on the assumption that 100% of projects will go through to completion that currently have planning permission; depending on finance, feedstock security, and the policy environment. Data source (NNFCC, 2017).
Of the additional 420 projects under development between 2017-2020, 309 (73%) of these will be farm-fed plants (installed capacity of 159.9MWe) and 111 (27%) will be waste-fed (installed capacity of 166MWe). This adds further justification for the development of an AD facility, specifically for use within the agricultural sector, as popularity and familiarity of AD is growing across the farming industry. Furthermore, based on the development pipeline, in the year 2017 to 2018 it is estimated that the use of manure feedstocks in AD could increase by 21%, from 1,487,000tpa to 1,800,00tpa assuming all plants go ahead as planned. However, given recent policy changes and a resultant relative decline in support for small-scale systems this rate of growth is not expected to transpire using current technologies (NNFCC, 2017).
Market Potential of AD Outputs Market research of both primary outputs from AD, biogas and digestate, and their possible applications are outlined in the following sections.
45
Deliverable 6.2 4.3.2.1 Biogas In recent years, interest in the production and consumption of biogas for bioenergy applications has increased significantly around Europe, driven in large part by implementation of the Renewable Energy Directive (RED) by the European Union. RED targets state that the EU must fulfil at least 20% of its total energy needs with renewables by 2020 through the attainment of individual national targets to encourage cooperation by member states (Commission, 2009). UK specific targets aim to generate at least 15% (234TWh) of total energy from renewable sources by 2020 including 30% (32-50TWh from biomass) in electricity, 12% in heat (36-50TWh from biomass) and 10% in transport fuels (up to 48TWh from biomass) (EU, 2009). The UK are over three-quarters of the way towards the 30% electricity sub-target (expected to exceed this by 2020) but not yet halfway towards the 12% heat target and renewable energy in transport has actually fallen in recent years (Figure 31). The UK have also set in law the Climate Change Act (2008); a legally binding target to reduce greenhouse gas emissions by at least 80% of 1990 levels by 2050, with requirements to meet carbon budgets every 5 years. As it stands, without significant intervention, the UK is set to miss agreed EU targets (UKGov, 2016) and is not on track to meet 2027 targets from the Climate Change Act. Therefore, the incorporation of new renewable technologies to the energy mix is of major importance in the current climate, particularly deployment of systems to provide renewable heat and fuels. Figure 30: UK trends in the use of renewable energy across heat, electricity and transport sectors (DECC, 2016)
Thousand tonnes of oil equivalent
In 2015, all bioenergy represented 70.7% of total renewable energy generation (including fuels, heats and electricity), with anaerobic digestion making up 3.4 % of total renewable energy generation (Figure 31), representing a small but growing capacity. In early 2017, the UK’s biogas capacity was 363.2MWe from 401 AD plants across the country and the widespread deployment of additional AD facilities could significantly increase this total (NNFCC, 2017). 46
Deliverable 6.2 Figure 31. Renewable energy use 2015 (BEIS, 2016).
An increase in biogas production with novel AgroCycle systems would improve the currently failing UK renewable energy targets. A closer look at the market activity of individual biogas outputs are described below. 4.3.2.1.1 Biogas to Electricity Electricity is one of the major outputs from the combustion of biogas derived from AD. UK electricity generation in 2016 totaled 338.6TWh, a 0.2% decrease on the year before. Figure 32 illustrates the total energy mix for electricity production in the UK for each quarter from 2013 to 2016. On average, gas’ share in electricity generation was 42.4% (143.5TWh). Coal’s contribution to UK electricity was 9.1%, a record low generation of 30.7TWh. Renewable energy contributed 82.8TWh the second highest year ever with a share of 24.4% and the percentage of nuclear energy in the mix was 21.2% with 71.7TWh. Finally, only 2.9% (9.8TWh) of UK electricity generation in 2016 was derived from oil or other sources (BEIS, 2017).
47
Deliverable 6.2 Figure 32: Total energy mix for electricity production in the UK for Q1-4, 2013-2016 (BEIS, Energy Trends, 2017).
Renewable electricity in these statistics refers to the production of electricity, primarily from wind, bioenergy, solar and hydro power sources. Figure 33 highlights the breakdown of renewable electricity between 2000 and 2015 and the rapid scale of development in this sector in recent years (BEIS, 2016). In 2016, wind energy was the largest contributor with a 45% share (consisting of 25% onshore wind and 20% offshore wind) followed by bioenergy which boasted 36% of the total share. Only 6.5% came from hydro power and 12.5% from solar photovoltaics (PV) (BEIS, 2017). Figure 33: Total renewable electricity capacity since 2000 (BEIS, 2016)
All waste combustion plant is included because both biodegradable and non-biodegradable wastes are burned together at the same plane. Hydro includes both large scale and shoreline and tidal (8.9 MW in 2015).
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Deliverable 6.2 The amount of electricity produced from bioenergy totals 29.8TWh. Table 6 demonstrates the production of bioelectricity from various biomass treatment methods from 2010 to 2016 (BEIS, 2017). In 2016, the majority of bioelectricity was generated from the combustion of plant biomass and this has been the case since 2013. The primary reason for this observation is that the UK’s largest power station, Drax, has converted three of its six coal fired boilers to run exclusively on wood pellets with estimated carbon savings of 80% compared to coal combustion1. The combustion of plant biomass has the potential to increase, as many of the UK’s coal facilities are closing and more dedicated biomass facilities are appearing, but the government is not keen to expand support for biomass combustion much further, due to sustainability concerns raised by NGOs and other forms of renewable electricity available. Anaerobic digestion contributed 1,874GWh to electricity generation, representing a 6.3% share of power produced from bioenergy. At present this fraction remains relatively small compared with other bioenergy sources, highlighting that there is huge potential for the AD sector to expand (BEIS, 2017). However, government incentives are now more favourable to biomethane production than AD electricity, as technology and deployment has developed, discussed later in 4.3.3 Market Incentives. Table 6: Electricity generated from bioenergy in the UK (2010-2015) (BEIS, 2017)
GWH
2010
2011
2012
2013
2014
2015
2016
Landfill gas Sewage sludge digestion Energy from waste* Co-firing with fossil fuels Animal Biomass** Anaerobic digestion Plant Biomass*** Total electricity generated from Bioenergy Total electricity generated from all sources
5,031
5,085
5,145
5,160
5,045
4,872
4,617
697
764
719
761
846
888
953
1,530
1,503
1,774
1,649
1,923
2,782
2,559
2,332
2,964
1,783
309
133
188
119
627
615
643
628
614
648
652
111
273
501
722
1,019
1,429
1,874
1,593
1,749
4,083
8,929
13,105
18,587
18,817
11,921
12,953
14,648
18,158
22,685
29,394
29,808
347,896
332,461
328,270
324,725
300,823
318,712
338,600
*biodegradable part only **including use of poultry litter, meat and bone ***including use of straw combustion and short rotation coppice energy crops
4.3.2.1.2 Biogas to Heat Heat is the second major output from biogas combustion and is used primarily in space and water heating, either domestically, commercially or across industry. It is estimated that approximately 50% of heat related GHG emissions come from domestic use at present, with 20% from the commercial sector and 30% from industry (Figure 34).
1
https://www.pellet.org/wpac-news/drax-fires-up-biomass-power
49
Deliverable 6.2 Figure 34: The share of GHG emissions produced by the domestic, industrial and commercial sectors.
Domestic Industrial Commercial
Heat generated from bioenergy is vital to meet renewable heat targets from 2% in 2014 to 12% in 2020. At present, heat is fuelled in large part by fossil fuels and in 2015 fossil-fuelled (mainly gas and oil) boilers generated 88% of heat, electric heaters provided 7%, bioenergy boilers (mainly wood chip combustion) generated 5% plus smaller amounts from emerging technologies (UKParliament, 2016). In addition, as biomethane enters the gas grid (described later), gas boilers are using more renewable fuels. However, in comparison with electricity generation, the amount of heat generated from renewable sources in general is minor and improvements must be made if the UK is to reach 2020 targets (Figure 30) (DECC, 2016). The opportunity for AD installations around the country is therefore huge as heat derived from renewables is now a fundamental goal, if suitable uses can be found nearby. Bioenergy has generated around 95% of renewable heat in the UK paid for under the Renewable Heat Incentive, totaling a cumulative 7,653GWh out of 8,077GWh generated between November 2012 and March 2016 (Figure 35). Figure 35. Heat paid for under the domestic and non-domestic Renewable Heat Incentive schemes, cumulative since November 2012 up to March 2016.
At present, most AD facilities generate heat, for parasitic purposes as well as external use. The use of biogas to generate heat exclusively is quite rare; in 2017 only 6 AD plants around the UK were used for this purpose, with the vast majority producing combined heat and power 50
Deliverable 6.2 (CHP) and/or biomethane. However, heat is generated in CHP engines as a by-product of electricity production, and this process heat is often used on farm for agricultural production, aquaculture systems or drying biomass. In addition, biomethane generated by AD is most commonly converted into heat, distributed as gas via the gas grid to homes and commercial properties. Therefore, the biogas generated in additional AD systems could enter both heat and electricity markets (NNFCC, 2017). 4.3.2.1.3 Biomethane markets Biomethane is the final major output derivable from AD biogas production and is utilised for multiple applications. The upgrading of biogas is used to remove impurities to obtain high purity methane, comparable to natural gas. Biomethane can be injected into the national gas grid to directly replace natural gas or be converted into liquid fuels for transport. These markets are discussed below. 4.3.2.1.3.1 Biomethane to Gas Grid Biomethane’s ability to be injected directly into the national gas grid allows the UK to make an easy transition to renewable technology without losing the key benefits of gas or having to build completely new infrastructure. Biomethane market potential is therefore assumed to be closely linked to methane markets as the applications of both resources are analogous. Figure 36 highlights UK demand for natural gas from 2013 to 2016. Note that the major use for gas in homes is currently for heating, and correspondingly there is more demand in the winter to heat homes, seen in Figure 36. A large amount of gas is currently imported into the UK, which could be replaced by domestic biomethane (Figure 37). The demand for methane is likely to increase further as electricity production from coal decreases, it is projected that gas electricity generation could fill the market gap (BEIS, 2017). Figure 36: UK demand for natural gas from 2013-2016 (BEIS, 2017).
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Deliverable 6.2 Figure 37. Import and export of gas by the UK
Traditionally, biomethane production is more expensive and complicated than the simple combustion of biogas for energy applications. High costs are not only related to the upgrading of biogas to biomethane, but to the charges applied to connect to the gas grid; sometimes costing hundreds of thousands of pounds depending on the location of the site and grid, and the requirement for biomethane’s energy density to be near equivalent to natural gas; requiring addition of propane in many cases (DECC, 2009). Hence, this is why at present there are significantly more CHP plants than BtG located around the country, particularly for small scale facilities. An alternative to local biogas upgrading generated from the AD plants, could be to send biogas to large scale centralised processing facilities via biogas networks (NNFCC, 2013). From here, biomethane could be injected directly into the grid, or upgraded to fuels or chemicals. A detailed analysis of the feasibility of the establishment of biogas networks in the UK is available from WRAP and NNFCC (WRAP, Biogas networks, 2013). It is more economical for larger AD projects to process their biogas onsite and the rewards from biomethane compared with biogas are superior. Additionally, thanks to government incentives which favour biomethane generation over CHP and the intention to phase out natural gas by 2030, the amount of BtG projects around the UK have increased significantly. At the beginning of 2016, around 47 projects had injected biomethane into the national gas grid. By the start of 2017, this figure increased to 77 (NNFCC, 2017) with an installed capacity of 45,000 Nm3/hr. Figure 38 demonstrates the main feedstock sources used to generate biomethane at the end of 2016 (Baldwin, 2016). Biomethane production is largely visible within agriculture therefore indicating market awareness and success, which are positive signs for the further deployment of AD to biomethane and commercialisation of the AgroCycle AD systems around the UK.
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Deliverable 6.2 Figure 38: Proportion of feedstocks used by biomethane projects around the UK by the end of 2016 (Baldwin, 2016).
Agriculture Food Waste Sewage Sludge Biodegradable
4.3.2.1.3.2 Biomethane to Liquid Fuel The conversion of biomethane to liquid fuels for use in transport is a rapidly emerging technology. Liquefied biomethane can be transported relatively easily compared with gaseous methane. Biomethane liquid fuel markets could enter some traditional transport fuel markets. Figure 39 displays the demand for different types of transport fuels, including diesel, petrol and aviation fuels in the UK. By far the most widely used liquid fuels across the UK are those derived from fossil oil. Figure 40 shows UK oil consumption trends in the UK and highlights the overwhelming amount of oil required by transport. Figure 39. Demand for key transport fuels (BEIS, 2017)
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Deliverable 6.2 Figure 40: Final consumption of oil from 2013 to 2016 (BEIS, 2017).
2
Figure 41. Bio-Bus in Bristol, powered by sewage and household food waste anaerobic digestion
However, vehicles need to be compatible with biomethane liquid fuels, and many cars on the road are not currently. Liquified biomethane can be dispensed to conventional LNG, or compressed natural gas (CNG), vehicles. Therefore, it is more likely biomethane fuels will displace liquid natural gas (LNG) markets (within ‘other’ uses of natural gas Figure 36), replace the imports of LNG represented in Figure 37, and make deals to convert fleets of buses and heavy goods vehicles to LNG. For example, in Bristol the local buses have converted to biomethane liquid fuels, which are called ‘Bio- buses’ (Figure 41). In 2016, 31 million litres of biomethane liquid fuels were supplied in the UK. However, this only makes up 2% of total renewable fuels in the UK, and renewable fuels only represent 3 % of total transport fuel consumption (DFT, 2017). Therefore, there is a huge market for biomethane fuels to expand into, if they can partner up with bus and heavy vehicle fleets.
2 http://new.geneco.uk.com/news/PooBusFleetBristol.aspx Photograph: Ben Birchall/PA
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Deliverable 6.2 Figure 42. Volumes of renewable fuels, by fuel type (DFT, 2017).
Note: Figures may not add up to 100% due to rounding.
In other countries, biomethane fuels are more widespread and successful. In many other countries unlike the UK, water and waste management is owned by the Government, allowing policy makers to direct the investment of biomethane facilities. For example, in Sweden biomethane fuels have been in production for decades. In Sweden, there are centralised biogas upgrading facilities which also act as filling stations for buses and other forms of transport (BiogasÖst, 2008). The revenue for centralised upgrading facility investment is estimated to turn a profit after 7 years of operation, with very worthwhile investment return after 20 years of operation (NNFCC, 2013). Other business models for upgrading and selling biomethane fuels include; small scale biomethane fueling stations on farms for rural transport, large scale centralised AD facilities combining AWCBs from multiple farms and organic waste, wastewater treatment to biomethane vehicles, and co-operation between gas companies, petrol stations and gas fueling stations (to sell the liquified gas) (BiogasÖst, 2008). 4.3.2.2 Digestate Unlike the biogas produced in AD, digestates are generally of low value and are not typically sold in commodity markets. Digestates are therefore commonly recycled by AD operators and dispersed on land as biofertilisers, minimising the requirement of synthetic alternatives. The amount of digestate expected to be produced in 2017 is estimated over 8.8 million tonnes in the UK, with a feedstock: digestate production coefficient of 0.87 (NNFCC, 2017b). Although this proportion may vary depending on feedstock and technology configuration, the average is expected to be relatively stable. A huge amount of digestate is produced, but the value depends on the initial feedstocks for AD, location and local demand. Digestate can even cost to be disposed of if not fully utilised by the operator. The potential value obtained for digestate is difficult to find out, except through industry survey. WRAPs latest figures suggest digestate market value between -£13 to £3 per tonne (NNFCC, 2017b). Schemes such as the Biofertiliser Certification Scheme (BCS) in the UK have recently been introduced to help operators get better value for safe, high quality digestate like the ones that will be produced with the proposed AD facilities. Thanks 55
Deliverable 6.2 to the BCS, certified digestate are on the rise nearing almost 2 million tonnes in 2015 (NNFCC, 2017b). Figure 43. PAS110 certified digestate, by nation (tonnes) time series (NNFCC, 2017b)
In comparison, synthetic fertilizers have higher market values compared with digestate manures because their nutrient contents are much easier to control and balance for each crop. As a result, there is a lot of research and development taking place into the separation and purification of nutrients from digestate, to gain higher market values for these materials in the future. These include: • Struvite Precipitation – the precipitation of magnesium ammonium phosphate (struvite) which can be used as an inorganic fertiliser. Does not fully remove all N, as P concentration is lower than N in digestate. • Ammonia Recovery – ammonium recovered for fertiliser or chemical feedstock, using waste heat (from a CHP) improves the efficiency of technique. • Acidification – acid addition to digestate decreases pH and increase ammonium, reducing N loss in field. Technique acceptability depends on soil type. • Alkaline Stabilisation – raises pH to kill pathogens and neutralise odours (mainly lime for sewage treatment). • Composting – pasteurisation at 70OC, and aerobic breakdown, increasing conversion of ammonia to nitrate which is more available to plants and stable. • Reed beds - to dewater, sanitise and mineralise digestate. • Biological oxidation – to reduce biological oxygen demand and ammonia (more common for sewage treatment). • Biofuel production – including using digestate liquor to feed algae (pilot scale), dewatered liquor to produce bio-ethanol, or hydrolysis and fermentation of digestate fibre (lab scale). • Microbial fuel cell – more novel technique to produce bioelectricity from biological oxidation of organic matter by microbes transferring electrons to an anode during respiration (lab and pilot scale). Figure 44 gives an overview of the markets that digestate currently and potentially could expand into, mainly as a fertiliser, fuels or energy recovery. In addition, there are also some more recent applications of digestate fibre, such as animal bedding and plastics.
56
Deliverable 6.2
Figure 44: Potential uses and resultant markets that digestates materials can enter (WRAP, 2012).
57
Deliverable 6.2
AD Market Incentives In recent years, several support mechanisms have been implemented by the UK government to incentivise the uptake of renewable energy technologies. Of specific relevance to anaerobic digestion are Feed-In Tariffs (FITs), Renewables Obligation (RO), Contracts for Difference (CfDs) Renewable Heat Incentives (RHIs) and the Renewable Transport Fuel Obligation (RTFO). Driving these financial incentives are the UK’s commitments to a number of green targets including an 80% reduction of carbon emissions compared with 1990 levels by 2050 (The Climate Change Act 2008), 15% of energy must be sourced by renewable sources by 2020 (EU Renewable Energy Directive), and the volume of biodegradable municipal wastes sent to landfill must be 35% of that produced in 1995 also by 2020 (EU Landfill Directive). AD is seen as a valuable technology in meeting these targets. Recently, UK government incentives have been more biased towards biomethane generation supported by RHIs compared with bio-electricity supported by FITs. This is because the UK is struggling to meet renewable heat supply targets and there are other forms of renewable electricity (wind, solar etc.) which can instead be used to meet electricity targets. Renewable fuels have stagnated over the past few years, while the Government decides whether to legislate the increase of renewable fuels in the total mix from 4.75% towards 10 %. The hiatus has been caused by effective lobbying by NGO’s on sustainability and land use issues of producing biofuels from crops. However, waste based biofuels are favourably seen by the government and the public, who are tightening up the sustainability of bioenergy. So much so, that sustainability criteria in all bioenergy incentive schemes now demand that feedstocks are from sustainable sources that emit less than 60% of fossil equivalents. In addition, policy will soon come into force that will allow no more than 50% of feedstocks in bioenergy to be from dedicated energy crops. This will provide an excellent boost for using wastes in bioenergy. 4.3.3.1 Feed-In Tariffs The Feed-In Tariff (FIT) scheme was introduced in April 2010, endorsing payments for smallscale (5MWe) (NNFCC, 2017). However, the RO scheme is now closed to new applicants, as of 31st March 2017. The RO has now been replaced by the Contracts for Difference. 4.3.3.3 Contracts for Difference From summer 2014, a Contracts for Difference (CfD) mechanism has been available to large scale renewable energy generators in the UK, adopted by the Government as part of the Electricity Market Reform (EMR). CfDs are only available for technologies at scales where no other support is available. As FITs are available for AD capacity up to 5MWe, this restricts eligibility for CfDs to AD plants with a total installed capacity greater than 5MWe. 4.3.3.4 Renewable Heat Incentives The Renewable Heat Incentive (RHI) scheme, is a means of rewarding the consumption of heat from renewable sources, including biomethane going into the gas grid and heat from CHP engines or biogas boilers. RHI payments are made to the owner of the heat installation over a 20-year period and tariff levels have been calculated to bridge the financial gap between the cost of conventional and renewable heat systems. A degression mechanism was also introduced (to non-domestic RHI) in April 2013 in order to control budgets. Table 8 demonstrates UK-wide non-domestic UK wide RHI tariffs from 2015-2017. Table 8: UK wide RHI tariff table (Ofgem, 2017)
Tariffs Before: Tier 1 (Up to 40,000 MWh Tier 2 (40,00080,000 MWh) Tier 3 (80,000MWh) Below 200 kWth 200-599kWth 600kWth and above
Apr 2015
Jul 2015
TARIFF (P/KWH) Oct Jan Apr Jul 2015 2016 2016 2016 Biomethane Injection
7.90
7.90
7.51
6.77
6.09
5.44
4.62
4.39
3.95
4.63
4.63
4.41
3.98
3.58
3.19
2.71
2.58
2.33
3.58
3.58
3.40
3.06
2.76
2.46
2.09
1.99
1.79
Jan 2017
Apr 2017
Biogas Combustion 7.90
7.90
7.90
7.09
7.90
7.05
5.99
4.50
3.37
6.21
6.21
6.21
6.22
6.21
5.54
4.70
3.53
2.64
2.33
2.33
2.33
2.33
2.33
20.7
1.76
1.32
1.00
59
Oct 2016
Deliverable 6.2 4.3.3.5 Renewable Transport Fuel Obligation The Renewable Transport Fuel Obligation (RTFO) supports the UK government’s policy on reducing greenhouse gas emissions from vehicles by encouraging the production of more sustainable renewable biofuels that don’t harm the environment. Under the RTFO, fuel suppliers in the UK must demonstrate that a certain percentage of their fuels come from renewable and sustainable resources. This only affects suppliers who supply at least 450,000 litres of fuel a year, but will have a wider effect on making all forms of bioenergy more commercially attractive, including liquefied biomethane derived from AD (DFT, 2012). Renewable Transport Fuel Certificates (RTFCs) are awarded for renewable fuels, which act as the incentive scheme as they increase the value of the fuel. If suppliers do not present the required RTFCs to represent the obligated renewable share of the fuel, they will be fined, and so will pay higher rates for renewable fuel than fossil fuels to ensure they meet the obligation. If selling to a large fuel supplier, the renewable fuel producer will get the price of the fuel, plus the deemed value of the RTFC, which changes over time depending on supply and demand. Otherwise, the renewable fuel producer can sell the fuel directly, and potentially make more profit by avoiding the ‘middle man’. This may be the preferred option, as a LNG and CNG are specialty fuels, and there is currently not a wide distribution of availability at filling stations across the county.
Market Displacement After outlining the market potential of AD’s products, it is important to acknowledge current markets that may be effected by expansion of AD. Indeed, the deployment of AD systems across the UK, and more widely across Europe, promises to increase AWCB valorisation, generating biogas and digestate. However, what effects will the introduction of these products have on existing markets? Biogas for use in energy applications will compete with traditional energy sources, namely fossil derived fuels and other renewable energy technologies. Digestate on the other hand will seek to displace the use of other soil/crop enriching species, primarily synthetic fertilisers produced by the chemical industry or even natural fertilisers such as manure. The remaining analysis for this case study will investigate the potential impacts of displacing these current markets with novel AgroCycle products.
Possible Markets Displaced by Biogas Biogas produced with novel AD systems will compete with traditional sources of energy. At present, the UK’s energy mix remains heavily reliant on fossil fuels, nuclear and various renewable technologies, as do many other EU member states. In 2016, the total production of energy in the UK was 126 million tonnes of oil equivalent (mtoe), including 17mtoe of renewable generation. Over 50mtoe was produced from oil, 40mtoe from natural gas, 15mtoe from nuclear, 10mtoe from bioenergy & waste (Figure 45). A further breakdown of renewable energy fuel use was presented previously in Figure 31. In 2016 total UK energy production increased, due to growth in oil, gas, bioenergy and nuclear outputs which offset the decline in UK coal production and reduced output from wind, solar and hydro (Figure 45). UK coal production decreased by 51% to a new record low due to the closure of all deep mines and remaining mines coming to the end of their operational lives. This is a pre-existing trend and so further decreases are likely to happen regardless of market displacement by biogas (BEIS, 2017).
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Deliverable 6.2 Figure 45: UK indigenous primary fuel production 2015 vs 2016 (BEIS, 2017).
Biogas use has the potential to contribute to and displace other sources of natural gas, electricity, fuels and heat as described previously. Based on their intended application, the deployment of AD facilities across the UK will particularly impact on previously existing energy mixes used in the agricultural industry. Although each system alone will have a very small impact on national statistics, if all farms in the country used AD systems to process their AWCBs then the cumulative impact would be huge. As many farms are in rural areas and typically off-gas grid in the UK, self-generation through AD could help many farms become self-sustainable and offer a potential to sell excess energy to local communities as a means of boosting the rural economy and supporting highly sensitive farm revenues. Due to government incentives, fossil fuels (oil, gas, and coal) would take the biggest hit as policies are in place to support renewables over fossil fuels to meet targets, with other forms of energy working alongside biogas from AD to displace fossil fuels to create a greener, more sustainable energy outlook. However, despite the environmental benefits of potentially displacing a fraction of fossil fuels in the UK, there could be social impacts of this change. In the UK, around 637,000 people are directly or indirectly employed by the current energy industry, representing 1 in 50 people in employment. The displacement of other energy sources could potentially lead to job losses in the fossil fuel sector, an unfavourable aspect of this proposed technology. However, there is also the possibility of jobs arising from AD expansion: in the design, manufacture, sale, installation, feedstock trade, operation/maintenance and feeding AWCBs into the new AD systems. Read more about job creation in the AD sector in NNFCC’s report “UK jobs in the bioenergy sectors by 2020” (NNFCC, 2012). This would be equally applicable in other EU member states, where a focus on domestic manufacture could enhance skills and employment at local, regional or national level. Overall, any setbacks of biogas production from this system can be compensated for by the huge positive environmental impacts that result from a deviation away from fossil fuels.
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Deliverable 6.2
Possible Markets Displaced by Digestate Digestate produced by AD systems competes with more traditional fertilisers, namely synthetic alternatives derived from the chemical industry or raw manure and slurry. Despite traditional fertilisers having more control over the nutrient content within, research and industry schemes (e.g. biofertiliser certification schemes) have been encouraging the development of the digestate market. Ultimately replacement of synthetics will not only have an impact on the chemical industry but, again, the fossil fuel industry and notably the environment. A huge portion of essential everyday chemicals are derived from petroleum building blocks, including fertilisers. Therefore, if AgroCycle AD plants were deployed across the UK, Europe and internationally, a decrease in demand for synthetic fertilisers due to digestate utilisation could be significant. This could benefit the environment, by reducing runoff of synthetic fertilisers into rivers which causes eutrophication, and reduce our dependence on limited mineral resources and the energy intensive production of fertilisers.
WP2: Closing Remarks The first case study outlined in this report (deliverable 6.2) has focused primarily on use of mixed AWCB in AD systems at different scales. AD technology is already deployed across the UK and the EU, but there is potential to continue the expansion and utilise a wider variety of AWCBs from farms across the UK, particularly small and medium farms. A variety of AWCB will be tested by AgroCycle researchers, namely manures, slurries and crop residues; the most common AWCBs available on working farms in the UK. More specifically, farm yard manures (FYM) were considered the primary feedstocks of interest throughout this case study as they are generated consistently throughout the year, unlike crop residues which are typically available nearer times of harvest. More importantly, these feedstocks are widely abundant across the UK and it is estimated that over 90 million tonnes are produced annually. However, at present, the full potential of these materials are not harnessed as the vast majority of FYM are spread on land as biofertilisers, with no energy recovery step. Due to the biological breakdown of manure during anaerobic digestion, essential nutrients within digestate become more readily available for uptake by soils and crops. Digestates are therefore widely recognised as useful biofertilisers for the enrichment of agricultural land. It is estimated that almost 9 million tonnes of digestate are produced in the UK already, which could increase in the coming years. Co-products could have huge potential in displacing conventional synthetic fertilisers throughout agriculture. Fertilisers manufactured by the chemical industry, although popular, are unsustainable. They are typically derived from non-renewable resources and require significant amounts of energy upon production. What’s more, once applied to land, they can be leached to surrounding areas and cause eutrophication, with no opportunity for nutrient recovery back to agricultural production. Digestates generated from the novel AgroCycle technology on the other hand, are much more sustainable, derived from highly abundant and renewable AWCBs. Nevertheless, synthetic fertilisers remain more successful in UK and global commodity markets for the primary reason that nutrient content is more easily controlled when manufactured by industry. As a result, conventional fertilisers attract much higher prices on the market place as more reliable and higher quality products are generally guaranteed. This highlights one of the main obstacles for AgroCycle digestates as it is unlikely that AD plant owners will receive any revenue from digestate supplies remaining after land application. Surplus biofertilisers 62
Deliverable 6.2 are anticipated, as fertiliser spreading in the UK must conform to limits set by the government, highlighting that it may not be feasible to utilise all digestate onsite. An opportunity to therefore trade excess digestate would add significant value to the system, providing additional incentive for the deployment of AD facilities to farms across the UK. Schemes such as the Biofertiliser Certification Scheme (BCS) in the UK have recently been introduced to help operators get better value for safe, high quality digestate like the ones produced by the proposed novel technology. This will therefore encourage the market development of biofertiliser digestates and thus the adoption of anaerobic digestion on farms. The second of the major co-products generated by the proposed AgroCycle technology is a carbon rich biogas. Biogas is a highly versatile product with primary applications in the bioenergy sector. For example, biogas can be combusted to generate heat, electricity, CHP (combined heat and power) or further upgraded to biomethane where it can be transformed in to transportation fuel or injected into the national gas grid. The UK is currently committed to a number of green targets including an 80% reduction of carbon emissions compared with 1990 levels by 2050 (The Climate Change Act 2008) and 15% of energy must be sourced by renewable sources by 2020 (EU Renewable Energy Directive). Biogas production from additional AD systems could help ensure these targets are met. To drive the uptake of renewable energy technologies the UK government has since implemented several support mechanisms. Of specific relevance to this case study are feed-in tariffs (FITs), renewable heat incentives (RHIs) and the renewable transport fuel obligation (RTFO). More specific UK targets state that 30% of all UK electricity must originate from renewable sources, 12% of heat and 10% of transport fuels. While there are other forms of renewable electricity (wind, solar etc.) and fuel, which can be employed to meet electricity and transport fuel targets, there are less efficient ways of generating heat renewably compared to bioenergy. At present, the majority of biogas is used in CHP; for heat and power applications. Despite the increased expense of upgrading and connecting to the national grid, biomethane production is expected to expand further in the following years as the government intends to phase out natural gas by 2030. By increasing tariffs on biomethane to gas (BtG) plants opposed to CHP facilities, the government can manipulate the generation of more biomethane for the displacement of natural gas from the UK’s energy mix. The production of biogas and biomethane from AD plants will not only compete with natural gas markets but also a range of other resources used for the production of energy, mainly oil, coal, wind, solar and nuclear. Alone, each system will have small impacts on national statistics. However, if all farms in the country used AD to process their AWCBs, then the cumulative impact would be huge. This represents a significant opportunity to replace unsustainable and environmentally damaging fossil fuels from the UK energy mix. Around 637,000 people are directly or indirectly employed by the energy industry in the UK, representing 1 in 50 people in employment. Therefore, if fossil fuel production decreases, then potential job losses may result. However, AD deployment also promises job creation through the design, manufacture, installation and operation and feedstock trading and handling of AD facilities, which could potentially offset fossil fuel sector job losses around the UK. In recent years, the AD industry in the UK has experienced rapid growth and the majority of all plants use predominantly farm derived feedstocks (e.g. manures, slurries, crops and crop residues). This outlines that there is already a steady and reliable market in this area. In addition, processing the AWCB from more small and medium farms could greatly expand the AD capacity in the UK. 63
Deliverable 6.2
5. WP3: Developing Novel Biofertilisers from Rice Bran The principal aim of work package 3 (WP3) is to assess the valorisation potential of a range of AWCBs (e.g. crop residues and livestock effluents) for the fertilisation of soils and crops. The following section of this report, will focus on the application of rice bran as a biofertiliser, as investigated by researchers at the Demeter Cereal Institute (Thessaloniki, Greece). Deviation away from the use of conventional synthetic fertilisers is a highly favourable objective within agriculture. Once applied to land, these synthetic fertilisers, often derived from non-renewable energy intensive sources, are quickly leached into the environment, causing water pollution and ecological damage. They represent a traditionally linear economy, whereby resources are completely used up within the system and then disposed of, making no opportunity for recovery or eventual recyclability. In the valorisation of waste residues however, a solution presents itself. A more sustainable, circular economy emerges when externally sourced fertilisers are avoided in favour of AWCBs produced within the agricultural supply chain. The application of a nutrient rich, bio-derived rice bran compost for the biofertilisation of future rice crops addresses these precise concerns, thus creating a truly cyclic system. Furthermore, subsequent rice paddy grown using such biofertilisers will give produce access to higher value organic rice markets. Figure 46 illustrates the key differences between a conventional linear supply chain vs a more sustainable circular economy. Figure 46: Representation of a traditional linear supply chain vs a more sustainable circular economy (Desso, 2017).
This technology is currently being developed in Greece, therefore this case study will aim to focus on potential feedstocks, supply chains, markets and policies specific to this country. This will help provide a more focussed discussion when determining whether the valorisation pathway outlined is beneficial from the perspective of the three pillars of sustainability (environment; social; economic), when compared to the business-as-usual scenario.
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Deliverable 6.2
Novel Pathway Description Summary of Pathway A pathway for the proposed application of rice bran as a biofertiliser is highlighted in Figure 47 as a novel cyclic system. An externally sourced fertiliser (synthetic or otherwise) is initially required to commence rice crop development in the first instance, after which point, rice processing will continue as standard. For example, following harvest, grains will be dried, cleaned and hulled to remove any recalcitrant elements of the paddy rice, to yield an edible brown grain. Additional processes can be employed (e.g. milling and polishing of the brown rice) to obtain a highly coveted white rice, alongside a valuable rice bran by-product. In Greece, where this novel research is being carried out, the current application of rice bran lies predominantly in animal feed. However, its favourable nutrient rich properties also give rise to promising applications in the enrichment of soils and crops throughout agriculture. The composting of rice brans and subsequent spreading on to future rice crops, reduces dependence on non-renewable substances, minimises waste production and above all could promote a more stable circular economy (Figure 47). Figure 46: Illustration of the proposed AgroCycle value chain for the novel application of rice bran/husk.
Green oval boxes highlight the key products generated within this system. Blue rectangles represent the processing methods required to produce said products. Grey ovals/rectangles demonstrate the products processes occurring outside of the novel circular supply chain, hence these follow more linear pathways.
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Deliverable 6.2
Rice Bran Pathway Feedstocks
Figure 47: Distribution of rice production across Europe in 2014 (FAOSTAT, Crops, 2017)
5.1.2.1 Rice Bran Feedstock Production European paddy rice production reached over 3.5 million tonnes in 2014, despite being neither a staple food or major crop in the region. The distribution of rice production across the EU28 in 2014 is shown in Figure 47, with the contribution from Greece a moderate 230,000 tonnes (6.4% of the EU28 total) (FAOSTAT, Crops, 2017). Locations surrounding the Greek city of Thessaloniki are the primary rice cultivating areas in the country (Ricepedia, Greece, 2017). The production of a rice bran feedstock for biofertilising applications can be effectively described by two succeeding pathways: rice plant cultivation followed by paddy rice processing. 5.1.2.2 Rice Plant Cultivation Rice plants initially need to be grown and successful rice cultivation relies largely on the servicing of fields before seeds can be planted, requiring farmers in Greece to begin preparations throughout March. Fields need to be carefully levelled using GPS or laser-guided equipment, ensuring that once flooded (to a depth of around 5 inches), water will remain, thus facilitating rice growth (Calrice, 2017). Rice in Greece is sowed directly into the water, which prior to 1982, was predominantly achieved by hand. Now however, sowing is fully mechanised (e.g. scattering using planes) and typically takes place during the months of April and May (D.Ntanos, 2017). Subsequent crop growth progresses through three key stages of development (vegetation, reproduction and ripening), as outlined by Figure 48. In the first 60-100 days, crops experience seeding and tillering in the vegetation stage, followed by panicle formation and flowering in the reproduction phase. At this point, rice plants will have reached peak height (typically 3ft (Calrice, 2017)) and an additional 30 days is required to allow crops to mature in the ripening period, before harvest. This harvesting typically occurs in October (Ricepedia, 2017). Table 9. Quantities of each compound typically required for the fertilisation of Greek soils (D.Ntanos, 2017).
Fertiliser N P 2O 5 K2O
kg/ha 140-160 40-60 60-80
Fertilisers are essential additives in the promotion of healthy and reliable crop growth to facilitate increased yields. In Greece, conventional NPK fertilisers are used and applied at three different intervals. The required quantities of each fertilising compound, for typical Greek soils, are highlighted in Table 9. Before seed sowing as basic fertilisation, around 40-45% of total nitrogen units are applied alongside all required phosphorous and potassium fertiliser compounds. 30-35% of the remaining N units are applied during the tillering stage and the rest during panicle initiation stage (at booting) (D.Ntanos, 2017).
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Deliverable 6.2 Figure 48. Development of rice across the three primary stages of crop development (RiceKnowledgeBank, 2017)
5.1.2.3 Paddy Rice Processing Flooded paddy fields must be drained and dried prior to harvest, to facilitate the mechanical collection (e.g. by combine harvester) of ripe grains. Harvested paddy in Greece can be expected to contain up to 18-22% moisture which, in order to prevent degradation, discoloration, mould growth or invasion of pests (e.g. birds, bacteria, parasites etc.), must be reduced rapidly (D.Ntanos, 2017). Grain drying can be achieved by blowing heated air across harvested paddy or by more traditional methods, utilising the sun to dehydrate grains on mats or pavements for example (i.e. in Spain) (RiceKnowledgeBank, 2017). However, in Greece drying is achieved only at air drying facilities. Storage of dried paddy is an almost inevitable stage in the processing of rice. It is preferred that rice is stored in paddy form as the husk protects the valuable grain within. Therefore, processing can continue after storage, once it is required. Paddy grains are generally stored in vacuum packed bags or in bulk in large refrigerated containers (FAO, 2017). Once rice is needed, the inedible protective coating surrounding the grains need to be removed. An initial milling stage is used which acts by rolling grains between two rollers to loosen the hull and remove it from the grain. This will be done in a continuous process, grains will be sieved, allowing smaller dehulled grains to be removed, unhulled grains will be captured and remilled to remove all existing husk. This stage also acts to clean the hulls, as any larger unwanted particles can be removed using this method. Rice husks can be combusted for heat and subsequent steam production used in the parboiling of rice. The resulting brown rice (botanical term: caryopsis) is edible. However, in these cases, the rice needs to be treated via a heat stabilising step as the residual bran layer is prone to rapid degradation. This bran can be further removed in an additional milling stage (polishing) and white rice is produced. An ideal milling process will result in the following fractions (Figure 50 and Figure 49) (RiceKnowledgeBank, 2017): • • •
20% husk 8-12% bran (depending on milling degree) 68-72% milled rice (depending on variety), consists of whole and broken rice 67
Deliverable 6.2 Figure 50: Typical composition of a standard rice grain
white rice
husk
Figure 49 Key components of a rice grain
rice bran
Rice Bran Logistics It is important, when describing the pathway of a novel technology, to consider the logistical requirements of the system. In this case, the logistics will address feedstock collection, feedstock storage and transportation of the materials. 5.1.3.1 Rice Bran Collection Collection of rice bran from source will depend primarily on the milling technique used. In the most common cases where milling machinery is used, ground up husks and brans will be collected directly in vessels as they are removed from the grain (D.Ntanos, 2017). 5.1.3.2 Rice Bran Storage Prior to storage, an important stage in extending the longevity of rice bran is via heat treatment. Rice bran contains endogenous lipases; a group of enzymes which rapidly catalyse the hydrolysis of rice bran oil to free fatty acids, leading to hydrolytic rancidity. Thus, making the material inedible to humans. Lipases can be deactivated by heating bran using various techniques. For example, one such method requires heating rice brans to 125◦C-135◦C for 1-3 seconds at 11-15% moisture and then holding at elevated temperatures between 97◦C -99◦C for 3 mins. Subsequent cooling, dry-heating or freeze-drying will ensue, followed by dryheating, microwave heating (MH)or autoclaving etc. (Kahlon, 2009), (Kim S.M., 2014). Stabilised rice bran has a shelf life of around 6 months (FAO, 2017). This stage is particularly important to avoid the degradation of rice bran when used in animal feed. It could be argued however, that in the novel valorisation pathway of rice bran, this somewhat energy intensive stage is not necessary as materials will degrade in composts regardless. Furthermore, storage requirements will be minimised in the novel pathway as brans can be composted immediately after collection. Since rice bran degradation is initiated within a matter of hours, it is more favourable to allow this degradation to occur within compost heaps opposed to additional storage containers to minimise the chance of nutrient losses to the environment. 68
Deliverable 6.2 5.1.3.3 Rice Bran Transport In a production line after the final rice product is generated, rice will be weighed and bagged before being loaded into trucks and transported to end destinations. In cases where rice bran is required for use in animal feeds for example, similar transportation methods will be employed. However, for the novel pathway described, it is possible to compost rice brans and husk onsite, thus minimising transport requirements. Furthermore, baggage requirements will also be reduced with an onsite composting facility as brans can be loaded into container waggons from the site of collection and unloaded directly onto compost heaps.
Rice Bran Valorisation and Products Due to the nutritional benefits of rice bran, this material at present is almost exclusively used as feed for animals and, to a lesser extent, humans. Therefore, the proposed composting pathway to generate biofertilising materials from rice bran is a highly novel concept not only in Greece but in all the rice growing EU countries. Once bran is produced, collected, transported and deposited at the site of valorisation the composting process will begin. Figure 51 highlights the three key stages that rice bran composts will proceed through. The general recipe for successful composting is: High C and N Content + Water + Air + Aerobic Bacteria + Fungi + Time Figure 51: The three stages of thermophilic composting (Cornell, 2017).
In the first three days, initial decomposition will take place by mesophilic microorganisms (those that survive at moderate temperatures i.e. 10-40°C). These microbes rapidly break down the soluble, readily degradable compounds e.g. sugars and starches and the heat produced in this biological process causes temperatures in the compost to rapidly rise. Once temperatures exceed 40°C, the mesophilic microorganisms that initiated the process become less competitive and are replaced by thermophilic (heat-loving) microbes (Cornell, 2017).
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Deliverable 6.2 During the thermophilic stage, elevated temperatures accelerate the breakdown of proteins, fats and complex carbohydrates like cellulose and hemicelluloses (the primary structural components in plants). As these compounds are broken down, their supplies diminish and biological degradation processes slow. Hence, less heat is generated over time and eventually temperatures begin to decrease. Mesophilic microorganisms again take over in a final maturation stage. Here, chemical reactions will continue within the compost to ensure that resulting material is stable and suitable for fertiliser applications (Cornell, 2017). A general overview of this process is that as micro-organisms breakdown the organic matter, carbon content reduces, but other nutrients become more concentrated, hence why they are ideal soil enhancing materials. Table 10: Nutritional composition of stabilised full fat rice bran (Rao, 2000)
NUTRIENT
CONTENT PER 100G
Proximate Principles
Protein Fat Minerals (Ash) Crude Fibre Carbohydrates Dietary Fibre Soluble Fibre Starch Free Sugar Energy Calcium Phosphorous Potassium Sodium Magnesium Silica Bulk Density
16.5 g 21.3 g 8.3 g 11.4 g 49.4 g 25.3 g 2.1 g 24.1 g 5.0 g 359 kcal 80 mg 2.1 g 1.9 g 20.3 mg 0.9 g 643 mg 0.39 g/ml
Micronutrients
Thiamine (B1) Riboflavin (B2) Niacin Pyridoxine (B) Pantothenic Acid Biotin Choline Folic Acid Inositol Iron Zinc Manganese Copper Iodine
3.0 mg 0.4 mg 43 mg 0.49 mg 7 mg 5.5. mg 226mg 83 µg 982mg 11.0 mg 6.4 mg 28.6 mg 0.6 mg 67 µg
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If the carbon content of a feedstock is too high, there will be more organic matter in the compost for microbes to digest, therefore temperatures will continue to rise until supply runs out. Combustion can occur if temperatures within composts are too high, therefore human intervention by mixing or turning is often required to lower core temperatures. Nutritional information is therefore useful to determine any potential issues surrounding feedstock composition during composting. Table 10 outlines standard nutrient values per 100g of stabilised rice bran (Rao, 2000). Collected rice bran feedstocks will often contain residual paddy husks with higher carbon content compared with the brans themselves. These can be considered favourable additives as they promote higher temperatures in composts, further aiding the breakdown of materials. In the final stage of rice bran valorisation, the composted products are spread across rice paddy fields to aid the cultivation of future rice crops, thus completing the circular pathway of the rice growing process.
Deliverable 6.2
Current Supply Chains of Pathway Feedstocks: Rice Bran Rice bran by-products are used for a variety of applications around the world, mostly for livestock or human consumption, but bran also has applications in combustion for energy, as dish washing detergents and for pickling foods for example. The WP3 case study considered throughout this report is based on the development of a novel rice bran value chain in Greece, aiming to generate biofertilisers via composting. The following section of this report will address existing rice bran supply chains to evaluate potential competition with the proposed technology.
Animal Consumption of Rice Bran It is estimated that rice bran contains roughly 80% of the nutritional value contained within rice. It is therefore a reliable source of nutrition for a range of animals and the addition of rice brans to animal feed represents a major use of these materials in Greece. Table 10 highlights a more detailed breakdown of rice bran composition, but in general, rice bran can be characterised as 15-18% protein, 14-18% bran oil and 30-40% digestible carbohydrates (Ruiz, 2016). As discussed previously, rice bran is high in fats which lead to rapid degradation of the material. Within two days, rice brans will be fully oxidised, turning rancid and exhibiting unpleasant tastes and smells as a result. It is not uncommon for animals to refuse spoilt brans in feed, therefore the heat stabilisation of these materials is essential. Ruminants and poultry are the most common animals to benefit from rice bran feed additives (RiceKnowledgeBank, 2017). Rice bran oil is a common product further obtained from stabilised rice brans. Oils are particularly favourable additives to equine feed since elite performance horses demand higher calorie diets than other farm animals. Bran oils contain 2.5 times more energy than conventional feeds and are digested more efficiently. Furthermore, horses can only consume certain volumes of food per day, therefore the addition of rice bran oil to diets reduces the amount of feed needed to meet daily energy requirements (Cubitt, 2014). Although rice bran is high in fats, it also contains relatively high levels of starch which can cause a number of health problems in horses. It is well documented that horses are ineffective at utilising starch and if fed in excess can lead to gastric ulcers, insulin resistance, laminitis and muscle myopathies (Allen&Page, 2013). Rice bran oils are therefore favoured as horse feed additives as these contain the same quantities of desired fats, without high levels of starch (Cubitt, 2014). In the interest of promoting a circular economy, it is important to point out that rice bran addition to animal feed will lead to the production of animal manures which, as discussed previously in this report, have huge potential in biofertiliser applications. These manures are commonly spread across rice fields two or more weeks before the preparation of soils for rice cultivation, thus limiting the need for synthetic fertilisers (RiceKnowledgeBank, 2012). This raises questions on the viability of the novel rice bran pathway as this existing supply chain has the potential to meet requirements for a circular economy without denying valuable food additives from animals in the process. Figure 52 highlights a typical pathway for the production and use of rice bran in animal feed.
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Deliverable 6.2 Figure 52: An existing supply chain for the use of rice bran in Greece.
Human Consumption/Application of Rice Bran Currently only a small fraction of rice bran produced worldwide is stabilised and used as human food, except in the consumption of brown rice where the bran remains on the rice. The majority is used as described above, in animal feed. However, human use of rice bran and their extracted oils is increasing globally due to the recognised health benefits of these materials. It is therefore useful to mention this growing market as a potential competitor of the novel pathway (GlobalMarketInsights, 2016). Rice brans are an excellent source of dietary fibre, aiding the maintenance of healthy weight by keeping stomachs fuller for longer after meals to prevent over eating. It is also claimed that rice bran can help to control blood sugar levels and cholesterol, offering longer term benefits i.e. lower risk of heart disease. Furthermore, rice brans are rich in essential minerals e.g. phosphorous for maintaining healthy bones, manganese for improved brain function and iron to aid production of red blood cells, essential for oxygen transport (RiceKnowledgeBank, 2017). However, despite notable health advantages, rice bran is currently underutilised as an additive in human foods throughout Greece. Unlike animals which are likely to consume higher quantities of bran to benefit from the nutritional properties of these materials, humans are unlikely to notice significant differences unless diets are drastically changed. Therefore, rice bran is not yet considered a major player in health supplement markets. Alternatively, rice bran oil can be used instead of conventional cooking oils and waxes derived from oils can be used in cosmetics applications. Again, these uses of rice bran are only minor compared with their applications in animal feed and thus pose no major competition upon implementation of the novel AgroCycle pathway. Another way to valorise rice bran in food and reduce the creation of AWCB, would be to promote the consumption of brown rice over white rice. Brown rice requires less processing steps than the valorisation of bran products as the bran is never separated from the grain. As a high value market, the consumption of brown rice could improve health and nutrition in society, as well as improving environmental and economical sustainability of the product. However, this highly depends on the value attainable for brown rice compared with rice bran products, and the palatability and demand for brown rice over white rice.
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Deliverable 6.2
Potential Markets for Novel AgroCycle Products A key goal of this report is to highlight the potential of AgroCycle products entering commodity markets. The following analysis will outline factors influencing the commercial viability of the novel rice bran pathway currently being investigated.
Greek Rice Market In 2014, Greek rice production totaled 229,900 tonnes, representing a total harvested area of approximately 30,720 ha. This makes Greece the 3rd largest rice paddy producing country in the EU 28 after Italy and Spain (Figure 53) (FAOSTAT, Crops, 2017). The majority of rice produced by the EU is consumed within Europe as rice markets outside of this region are dominated largely by Asian nations, where rice is a staple food and an essential commodity. Despite such major competition globally, the EU produces roughly two-thirds of its total rice consumption with only a third imported from outside the region (Mintec, 2012). Figure 53: Top rice paddy producing nations within the EU 28 in 2014 (FAOSTAT, Crops, 2017).
Since 1980, rice production within Greece has almost trebled (Figure 54). Despite suffering heavily as a nation from the effects of the global financial crisis, rice production within Greece has continued to rise whilst other areas of agriculture have taken a huge hit (FAOSTAT, Crops, 2017). Furthermore, in recent years, adverse weather conditions have seen certain commodities decline significantly (see Greek peach, apple and pear market data in WP4: Development of a Novel Wastewater Facility). Where the quality of many crops in Greece are ruined by increased precipitation, rice paddy crops are less effected. Providing night time temperatures stay above 15°C for at least 3 months of the year, rice crops can be considered relatively safe from increased rain fall in Greece compared with other crops (Bose, 2013).
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Deliverable 6.2 Figure 54: Rice production and consumption in Greece from (1980-2014) (FAOSTAT, Crops, 2017) (Ricepedia, 2017).
These positive trends in Greek rice production are also an indicator of the potential availability of rice bran in the country. In theory, the more rice paddy produced, the more bran that will become available as a feedstock for the novel AgroCycle pathway. The total milled rice shown in Figure 54 (red) is more representative of the amount of rice bran that will be available in Greece as this is the amount that is actually processed within the country. Milled rice production within the country has grown steadily over the past three decades with no signs of slowing. It is therefore reasonable to assume that rice bran will be produced proportionately. It has already been discussed that the majority of rice bran at present is used in animal feed. However, as rice production increases, this could present an opening in the market for additional uses of rice bran. Furthermore, due to the typically low market price of bran, and as increasing supply often devalues commodities, the surplus bran is unlikely to gain high value on the open market. Therefore, the valorisation of materials in this situation could be more beneficial, whereby value is made from upgrading otherwise unwanted wastes. For example, in the proposed AgroCycle pathway, rice brans are composted with minimal effort to generate a higher value biofertilising material, reducing the need for purchasing additional crop fertilisers. Figure 54 highlights that the quantities of milled rice and rice consumed are comparable, indicating that the majority of rice consumed in Greece is that of the white variety. However, the quantity of total paddy rice produced is notably higher than the levels consumed within Greece. This difference can be attributed to the export of native rice and in 2014, of the 229,900 tonnes of rice produced in Greece, 42.5% (97,753 tonnes) was exported to neighbouring EU countries to satisfy foreign demand (Figure 55).
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Deliverable 6.2 Figure 55: Import and export quantities of rice in Greece from 1980-2014 (FAOSTAT, Crops, 2017).
Figure 56 further outlines the value of Greek rice import/exports in the same period and data indicates that substantial value can be gained from exporting to foreign markets. In 2014, Greek rice exports alone gained a value of over $60.5 million (FAOSTAT, Crops, 2017). Figure 56: Import and export values of rice in Greece from 1980-2014 (FAOSTAT, Crops, 2017).
Most rice varieties grown around Europe belong to the Japonica grain whereas demand for the less common Indica variety is growing at a rate of around 6% per year (Ricepedia, 2017). Unlike all other European countries, Greece produces Indica in higher quantities than Japonica thus establishing itself as a key producer in this emerging market, perhaps explaining why export trends have increased so significantly in recent years (Figure 56) (EuropeanCommision, 2015).
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Deliverable 6.2 Table 11: Highlights land area dedicated to the two main varieties of rice, Japonica and Indica, in each rice producing country within Europe (EuropeanCommision, 2015).
LAND AREA (HA)
2010/2011
2011/2012
2012/2013
2013/2014
2014/2015
Japonica
Indica
Japonica
Indica
Japonica
Indica
Japonica
Indica
Japonica
Indica
IT
174,159
73,494
181,063
65,478
174,974
60 078
144 573
71 446
164 234
55 298
ES
63 718
58 747
62 936
58 810
72 452
52 687
65 583
43 037
58 235
43 003
PT
22 903
5 027
22 905
6 745
24 936
6 500
25 000
6 174
16 243
12 425
GR
10 520
23 200
10 835
21 743
8 584
21 832
9 690
17 690
15 433
10 573
FR
16 000
2 800
18 481
3 000
18 805
3 175
14 500
3 500
13 743
1 207
BG
11 059
70
10 983
70
8 711
509
9 595
130
9 839
31
RO
5 300
8 000
10 748
1 912
10 000
1 000
7 750
3 806
9 528
1 733
HU
2 500
0
2 500
0
2 463
0
3 000
0
2 191
0
EU
306 000
171 000
320 000
158 000
321 000
146 000
280 000
146 000
290 000
124 000
However, as paddy rice production continues to rise within Greece, it is worth considering that bran trends may not follow in the future due to increased exports of Greek rice. If exported, the processing of rice paddy will occur outside of Greece thus generating bran feedstocks elsewhere. This is potentially problematic for the novel AgroCycle process as less rice brans may be available in the country.
Greek Fertiliser Market The main product generated in the proposed AgroCycle system is a novel biofertiliser derived from the composting of rice brans. Although the intention is to use said biofertilisers primarily in future paddy rice production, there is clear potential for their application elsewhere in agriculture. This next section will briefly outline current trends in Greek fertiliser use, to assess the potential of novel AgroCycle biofertilisers within this industry. There are three primary macronutrients used across agriculture for the fertilisation of soils and crops. These are nitrogen (N) for aiding leaf growth, phosphorous (P) for the development of roots, flowers, seeds and fruits and finally potassium (K) for strong stem growth, improving water transport and promoting flowering and fruiting. Additional macro and micronutrients are also available, but their significance is dwarfed by the importance of the three main NPK nutrients described above. In rice paddy production, NPK fertilisers play an important role in the enrichment of soils and crops. Figure 57 highlights the annual quantities of synthetic NPK fertilisers used in Greece, specifically in the rice growing industry. From 1960 to 1990 there was a notable increase in NPK usage whereas trends steadily declined after this point. It is likely that EU intervention via the Nitrates Directive in 1991 influenced these trends by limiting nitrate application on land throughout Europe (EuropeanCommision, 1991).
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Deliverable 6.2 Figure 57: Annual quantities of NPK fertilisers used in rice paddy production in Greece (Ricepedia, 2017).
Furthermore, these primarily inorganic (lack of carbon) fertilisers are traditionally manufactured from synthetic chemical processes meaning they rely heavily on the Greek chemical industry, while the environmental pollution during these industrial processes is a concern. However, since 2010, the beginning of the financial crisis in Greece, the chemical industry has suffered from instability. Smaller companies are fighting to survive while larger companies are having to adjust under the circumstances. The chemical industry has experienced a decline in output as a result, with related downstream sectors (i.e. fertiliser manufacture) also effected (ICIS, Greek chemical industry to decline in 2015-2016, 2015). As the Greek chemical industry continues to battle political and economic challenges, reliance on imports has become more pronounced. The value of fertiliser imports (and exports) is shown in Figure 58 with the purchase of foreign N compounds in particular, demonstrating a rapid increase. Figure 58: Import and export values associated with NPK fertilisers in Greece (FAOSTAT, Crops, 2017).
A demand for inexpensive, home grown biofertilisers e.g. those from rice bran, is therefore high. Proposed AgroCycle biofertilisers offer the chance to deviate away from importing
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Deliverable 6.2 chemical goods, reducing the dependence on foreign industry as well as the instabilities surrounding Greek chemical manufacture.
Greek Compost Market The AgroCycle system under question will more specifically generate biofertilisers from composted materials. Within Greece, sustaining soil productivity is of primary concern to farmers as soils in the region typically display low organic matter content. Therefore, compost is a useful commodity and an ideal waste treatment method for many AWCBs. Traditionally, Greece would not be considered at the forefront of the commercial composting sector. For example, Figure 60 demonstrates the nature of municipal solid waste recycling (MSW) in Greece, with data in green highlighting the amount recycled by composting or other biological treatment methods. Prior to 2010, no more than 2% of MSW was composted in Greece. In fact, no commercial composting at all was reported in 2003 or 2004 (I. Bakas, 2013). Figure 59: Greek recycling of municipal solid wastes (MSW) (I. Bakas, 2013)
Figure 60 further demonstrates how commercial composting in Greece compares with some of the best composting nations around Europe (ΣΕΚ, 2012). However, there is little information available about other feedstocks being composted, such as residues from gardening, industry, forestry and agriculture for example. Figure 60: European nations with the best composting performances compared with that of Greece (ΣΕΚ, 2012)
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Deliverable 6.2 A number of mechanical biological treatment plants (MBT) which combine a sorting facility with a form of biological treatment (i.e. composting or AD), have since been established, aiming to promote better waste recycling in Greece (I. Bakas, 2013). For example, the Athens Biowaste project was an EU funded initiative running from 2011 to 2014, aimed at implementing better biowaste separation at source to produce high quality composts. For the first time, compost quality analysis took place in Greece allowing for better planning and design of novel composting facilities to be developed. Furthermore, the project raised public awareness of the importance of biowaste recycling and the benefits of composting in particular (BioWaste, 2014). A number of targets have been set at a national level to raise recycling rates as part of transferring EU Waste Framework Directive into Greek legislation, including increasing the rate of total MSW recycling to 50% and bio-waste recycling to 10% by 2020. Greek compost markets are therefore set to increase as a result of increased recycling efforts and the 4% of MSW composted in 2014 is expected to rise significantly in the coming years (EuroStat, 2016). The positive sign for AgroCycle composts is that they could fill a market supply gap in an otherwise small composting sector. However, with supply increasing from the composting of MSW, the value of Greek composts ranging from inexpensive conventional to expensive organic ones (€6 to 20 per 100L) may decrease further (Skroutz, 2017) Table 12 further demonstrates the potential revenue Greek composts could expect to make depending on their selected application. These figures are based on data gathered from alternative compost markets around Europe (ΣΕΚ, 2012). Table 12: Potential revenue obtainable from selling composts in Greece (ΣΕΚ, 2012). APPLICATION
MARKET SIZE
PRICE (€/T)
Agriculture Soil Redevelopment Gardening
45-78% 2-10% 6-7%
0-28 1-2 5-320
Potential Markets Displaced by AgroCycle Products It is important when considering novel supply chain pathways to also think about the existing markets that could be effected by the adoption of AgroCycle products. Of course, encouraging the composting of rice bran will help to promote a truly sustainable, circular system. However, the novel process will not be preferable if problems surrounding the displacement of current markets outweigh the potential benefits. The remaining analysis for this case study will therefore investigate the potential impacts of displacing these markets.
Displacement of Existing Fertiliser Markets Existing fertilisers used in the cultivation of rice crops are primarily derived from the chemical industry. In particular, those containing NPK nutrients are the most widely used in Greece and therefore occupy the largest share of fertiliser markets. As a result, it is these fertilisers that will most likely be effected by the introduction of rice bran biofertilisers into the market place.
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Deliverable 6.2 5.4.1.1 Nitrogen Fertilisers To be able to assess whether the displacement of synthetic fertilisers will have positive or negative effects on sustainability, it is useful to first gain an understanding of how they are manufactured within industry. Nitrogen fertilisers mainly contain N in the form of ammonia (NH3) or compounds derived from ammonia I.e. ammonium (NH4+) or urea (NH2CONH2) for example. On an industrial scale, ammonia is generated by the Haber-Bosch process, reacting elemental nitrogen from the atmosphere with hydrogen derived from natural gas: N2(g) + 3H2(g) à 2NH3(g) Furthermore, this reaction proceeds via the addition of metal catalysts under elevated temperature and pressure, indicating that large inputs of energy are required. The HaberBosch process strongly relies on the use of fossil fuels for energy generation and in providing hydrogen gas as a feedstock. The Haber-Bosch process generates over 100 million tonnes of nitrogen based fertiliser annually, consuming in the process a full 1% of the world’s energy supply in the form of natural gas. Through manufacture of fertilisers and subsequent food production, the Haber-Bosch process is directly responsible for sustaining approximately 40% of the Earth’s population (Bloch, 2009). However, dependence on such a process, using finite and environmentally damaging fossil fuels, is unsustainable in the long term and the opportunity to instead use more renewable, greener fertilisers is therefore highly favourable. What’s more, the ammonia generated in this process is an extremely hazardous substance with a strong pungent odour and great care must be taken when handling to avoid losses to the environment. This provides an even greater incentive to replace the use of nitrogen fertilisers within agriculture with sustainable, safe to use rice bran composts as biofertilisers. 5.4.1.2 Phosphorous Fertilisers Figure 61: A typical potassium cycle used for the The majority of all phosphorous used in fertiliser fertilization of crops (IPNI, 2010). production is derived from the mining of minerals from rocks and more than 85% of rock phosphates mined across the world are used to make fertilisers (Jasinski, 2013). Demand for rock phosphates therefore relies heavily on trends in global food production which continues to rise year on year. These minerals are however, finite and as demand increases, supplies will become depleted, promising a significant rise in wholesale prices in the future. It is predicted that if current production levels continue, then the world will exhaust rock phosphorous reserves in less than 80 years (MIT, 2016). What’s more, mining typically requires the use of heavy machinery and high energy inputs, most likely depending on the combustion of fossil fuels. The displacement of phosphorous fertilisers with rice bran composts will therefore minimise the depletion of natural rock phosphorus resources by recycling nutrients stored within biomass. Furthermore, energy input will be reduced, thus limiting the combustion of finite fossil fuels. 5.4.1.3 Potassium Fertilisers Potassium fertilisers also depend on the mining of nutrients. Common K compounds required for crop fertilisation are potassium chloride (KCl), potassium sulphate (K2SO4), potassium carbonate 80
Deliverable 6.2 (K2CO3) and potassium nitrate (KNO3). Collectively, these minerals are known as potash. Figure 61 illustrates a typical potassium cycle whereby minerals are mined from salts and used as fertilisers. After the consumption and excretion of fertilised crops, minerals may leach into rivers and seas where they can accumulate again as salts (Figure 62) (IPNI, 2010). This process represents a cyclic system similar to that of rice bran fertiliser production. Figure 62: Traditional salt water brine, where salt accumulates from waters and acts as a source for However, in comparison, the mining of mineral recovery (IPNI, 2010). nutrients from salt beds requires significantly more energy due to the requirement of heavy machinery. The production of rice bran biofertilisers will instead require the simple pile up of brans after their collection to form composts. The spreading of composts will require the same energy inputs as would have been previously used for conventional fertiliser spreading. The displacement of potassium fertilisers with rice bran composts therefore offers the opportunity to reduce energy consumption and therefore reduce carbon emissions from the use of fossil fuels. 5.4.1.4 Greek Chemical Industry The Greek chemical industry accounts for roughly 5% of manufacturing within Greece, employing over 17,000 people around the country, demonstrating a total turnover of €2bn (ICIS, Greek chemical industry to decline in 2015-2016, 2015). Due to the low price of the imported fertilisers and the situation after the 2010 financial crisis in Greece, the industry is already struggling. By displacing the use of synthetic fertilisers from the chemical industry, this could put even more Greek jobs at risk, putting significant strain on the Greek economy. Rice bran composts will be contained within paddy rice farms, minimal labour will be required, thus creating no extra jobs. However, fertiliser production accounts for only a fraction of the total chemical industry (approximately 6% in Europe), and of these fertilisers displaced, only those in rice paddy cultivation will be effected initially (Figure 63) (Cefic, 2015). Therefore, the overall impact of displacing synthetic fertilisers on the chemical industry should be insignificant, with job losses minimal.
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Deliverable 6.2 Figure 63: Market sector breakdown of the EU chemical industry (Cefic, 2015).
5.4.1.5 Biofertilisers Finally, it is important to address the impact that implementation of novel AgroCycle composts may have on other environmentally friendly and sustainable biofertilisers e.g. other composts, digestates and animal manures. It is unlikely commercial markets of composts will be affected by the rice bran composts, as compost application to rice paddy fields is not common. Livestock manures on the other hand are more widely used as biofertilisers, and they can be collected from nearby farms to enrich local soils at a reduced cost. Nutrients in manures are more readily available to plants compared to composts and undigested rice bran, making their effectiveness as a biofertiliser better for crop yields in comparison. The traditional use of rice bran at present is in animal feed applications. Once consumed, feed will then be deposited as manure which can then be applied to land as a fertiliser (Figure 52). This value chain achieves essentially the same end goal as the proposed AgroCycle system, except in the existing pathway, animal feed is not displaced and required from an alternative source. This therefore raises ethical questions on sustainability of the novel value chain.
Displacement by Animal Feed Markets The consumption of rice bran by farm yard animals presents a pathway whereby biofertilisers are already generated from the production of inevitable manures. Fundamental concerns therefore arise when feeding animals is omitted from rice bran valorisation, raising questions about sustainability and general viability of the proposed system. However, there is an abundance of alternative feed manufacturers around Greece producing fodder from other crops such as alfalfa, soybean, corn and silage for example (AnimalFeed1, 2017). The withdrawal of rice bran from animal feed will instead see an increase in the consumption of these feed varieties. If rice farmers are to sell rice brans to nearby farms as feed for animals, little monetary value would be offered and there may even be a small charge when later acquiring associated manures as fertilisers. The production of rice bran composts however, will create a very effective fertilising material, safer to use than manure, which will ensure that synthetic
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Deliverable 6.2 derivatives are not needed. If composts are generated in excess of crop demand, these materials can then be sold in the market place.
Displacement of Rice Markets One of the major problems in conventional Greek rice production is that the inputs required for cultivation are high, leading to high production costs (energy, fertilisation, pesticides and water etc.), even though yields are among the highest in the world. The impact of this is that conventional rice production is unsustainable and production is expensive. Over recent years, as production costs have continued to increase, rice prices in Greece have declined, making it particularly difficult for growers in the country to compete with international production. High costs and low prices in Greece are caused in large part by Asian imports who, in 2016, reduced prices by more than 30% (€220 to 250 per tonne). As a result, many Greek rice farmers sold their rice in 2016 at prices lower than the cost of production. However, one way of making Greek rice more competitive, is to improve the quality of the produce by producing either organic rice or more sustainable agricultural products, certified by approved stamps recognising small environmental footprints. For example, the production of organic rice by minimising the use of agrochemicals such as synthetic fertilisers during cultivation, will not only reduce production costs (from minimising inputs), but will also attract a higher value rice compared with conventional products. Many consumers from Greece and Europe are ready to pay a higher price for better quality produce, while most organic rice products in Greece are imported. This therefore presents an opening in the market for domestic organic rice production. Rice can only be classed as organic when alternative certified agrochemicals such as fertilisers are used. Therefore, adopting greener, more sustainable fertilisers, such as composts, will promote the production of a more valuable rice product. This highlights that the rice bran composts discussed throughout this case study have the potential to produce a more competitive organic rice product, therefore threatening to displace organic rice production within Greece. Changing conventional rice production systems into organic ones will also have the effect of reducing the supply of local conventional rice. However, the international market for rice is so large that it is likely imports of rice can fill this market gap for cheap rice.
WP3: Closing Remarks
The second case study outlined in this report (deliverable 6.2) has focused on the application of rice bran as a biofertiliser, as investigated by researchers at the Demeter Cereal Institute (Thessaloniki, Greece). The proposed technology aims to deviate away from the use of conventional synthetic fertilisers by promoting a more sustainable, circular rice cultivating economy in Greece. By exploiting by-products of the rice manufacturing process (i.e. rice brans/husks) for the production of novel biofertiliser composts, dependence on chemical fertilisers will reduce and more valuable organic rice will be grown as a result. Conventional synthetic fertilisers are often derived from non-renewable energy intensive sources and once applied to land they are easily leached to surrounding areas causing water pollution and ecological damage. They represent a traditionally linear economy, whereby resources are completely used up within the system and then disposed of, making no opportunity for recovery or eventual recyclability. Furthermore, these materials rely heavily on the chemical industry, which since the Greek financial crisis in 2010, has suffered from severe instability nationwide. Consequently, Greek chemical output has experienced a steady 83
Deliverable 6.2 decline, which has had knock on effects on downstream sectors, including fertiliser manufacturing (ICIS, Greek chemical industry to decline in 2015-2016, 2015). Imports of foreign fertilisers have therefore increased, indicating that there is market demand for inexpensive home-grown biofertilisers. AgroCycle composts therefore offer the opportunity to deviate away from dependence on foreign industry and instable Greek chemical manufacturing. However, at present, the composting sector is not well established in Greece. For example, in 2014, only 4% of all MSW was composted around the country (I. Bakas, 2013). To improve the current situation, a number of targets have been set at a national level to improve recycling rates as part of the EU Waste Framework Directive (e.g. total MSW recycled raised to 50% and bio-waste recycling to 10% by 2020). Greek compost markets are therefore projected to increase indicating that AgroCycle products could fill a market supply gap in an otherwise small composting sector. The novel pathway proposed will initially utilise externally sourced fertilisers (synthetic or organic) to commence rice paddy production. Paddy rice will grow and undergo processing as standard and the major by-products (rice bran and rice husk) will be recovered for composting. During composting, microorganisms break down organic matter in the biomass. As carbon content reduces, other nutrients become more concentrated and more available for soil or crop uptake. These ideal soil enhancing materials can then be spread across paddy rice fields to aid the cultivation of future rice crops. This final stage completes the circular pathway of the novel rice growing process. It is estimated that rice bran contains roughly 80% of the nutritional value contained within rice therefore these materials are traditionally used as feed for animals. However, for these applications, a heat stabilisation stage is essential to extend the longevity of rice brans. Within two days rice brans will be fully oxidised, turning rancid and exhibiting unpleasant tastes and smells as a result. It is not uncommon for animals to refuse spoilt brans as feed. For use as biofertilisers however, rice brans can potentially omit this somewhat energy intensive heat treatment stage as materials will degrade in composts regardless. Furthermore, since rice bran degradation is initiated within a matter of hours, it is favourable to allow biomass breakdown to occur within compost heaps rather than alternative storage units to minimise nutrient losses to the environment. This therefore reduces storage requirements compared with rice bran for animal feed, and when compost heaps are located at the site of rice bran production, transport is also minimised. However, in the interest of promoting a more circular economy, it is important to point out that utilising rice brans as animal feed will lead to the production of animal manures which are also common biofertilisers throughout agriculture. These manures also offer the opportunity to limit synthetic fertiliser use, raising questions on the viability of the novel rice bran pathway. This existing supply chain has the potential to meet the requirements of a circular economy without denying valuable food additives from animals in the process. The proposed AgroCycle pathway however, aims to promote more than just a sustainable circular rice growing economy. One of the primary problems surrounding traditional Greek rice production at present is that cultivation inputs (e.g. energy, water and fertilisation) are typically very high. Growing rice is therefore becoming increasingly expensive and unsustainable. As production costs have continued to rise over recent years, rice prices have steadily declined, making it sufficiently more difficult for rice growers in Greece to compete with international production. One way of making Greek rice more competitive, is to therefore improve the quality of produce. The production of organic rice, by minimising the use of 84
Deliverable 6.2 chemical fertilisers, will not only reduce production costs (from minimising inputs), but will also attract a higher market value compared with existing inorganic rice produce. AgroCycle composts produced from rice production by-products will therefore promote higher quality, higher value rice, thus making Greek produce more competitive in both domestic and international markets.
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Deliverable 6.2
6. WP4: Development of a Novel Wastewater Treatment Facility The key objective of work package 4 is to investigate the treatment and potential exploitation of agricultural wastewaters generated from agro-industrial sources (e.g. fruit juice processing, wineries and olive oil production), and livestock wastes (e.g. wastewater slurry streams). The following section of this report will focus on one of the novel pathways being developed in WP4; a novel wastewater treatment facility currently under development at the Centre for Research and Technology-Hellas (CERTH) in Thessaloniki, Greece. The proposed system will be modular in design, demonstrating multiple treatment stages for the valorisation and eventual clean-up of fruit processing wastewaters. This novel treatment facility will aim to promote the initial recovery of value-added compounds from waste streams followed by biogas production from AD. Finally, waters will be made recyclable through advanced tertiary treatment (Membrane Bioreactor technology). Traditionally, wastewater treatment techniques omit such advanced valorisation steps in favour of promptly cleaning waste streams to meet regulatory standards for either discharge to nearby water bodies or applications such as irrigation for example (FAO, 2017). The proposed AgroCycle system however, will aim to promote the treatment of wastewaters whilst at the same time recovering value from the system.
Novel Pathway Description Summary A proposed pathway for the novel treatment of fruit processing wastewaters is outlined in
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Deliverable 6.2 Figure 64. The system will consist of three subsequent treatment techniques, defined as: 1. Recovery of value-added compounds 2. Anaerobic digestion (AD) of resulting liquids 3. Advanced filtration of final effluents Incorporation of steps 1 and 2 promotes the exploitation of valuable products from wastewaters, with step 3 essential for the eventual recycling of water. Recoverable outputs are shown in green, with their potential applications emphasized in orange (
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Deliverable 6.2 Figure 64). Recovery of bioactive compounds (e.g. polyphenols) will be pursued for specific fruit processing wastewater streams that contain bioactive compounds, i.e. winery wastewater streams, through membrane separation processes. In other wastewater streams that do not contain significant quantity of bioactive compounds, Single-Cell Protein (SCP), will be produced, exploiting the ability of specific yeast strains to grow on sugar-containing wastewater streams, such as juice processing and fruit canning. Their cultivation and recovery will be achieved using novel processes, under development specifically for this project.
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Deliverable 6.2
Figure 64: Proposed pathway for a novel fruit processed wastewater facility.
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Deliverable 6.2 A biogas co-product will also be recovered via the anaerobic digestion (AD) of subsequent wastewaters. Unlike the novel AD system proposed in WP2 however, the use of AD here will yield significantly less biogas as organic matter will be present in waters in much lower quantities. Nevertheless, compared to current aerobic treatment of fruit processing wastewater, AD requires much less energy, whereas at the same time biogas can be used for steam production in the fruit processing facility, substituting part of the energy needs, which is currently covered by fossil-fuels. Advanced filtration via membrane bioreactor (MBR) technology can then finally be applied in stage three, to yield a high-quality effluent, available for reuse in many applications. The separated solids from each stage, will be collected in the form of a sludge and further valorised via composting or AD (DairyFarmGuide, n.d.).
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Deliverable 6.2
Fruit Wastewater Production Since the introduction of the EU Urban Wastewater Treatment Directive in 1991, efforts around Europe have been boosted to minimize the environmental damage caused by wastewater discharge (EuropeanCommission, 1991). In general, the response has been positive. However, progress in recent years has regressed and Figure 65 demonstrates that in the period between 2004-2014 wastewater production almost doubled, whereas the production of all other wastes either declined or remained constant (EuroStat, 2016). These trends are concerning and highlight the importance of research and development into improving wastewater treatment across the continent.
Waste Generation (million tonnes)
Figure 65: EU28 waste generation, excluding major mineral wastes, for the period 2004-2014 in million tonnes (EuroStat, 2016).
To gain a holistic overview of the case study under investigation, the production of wastewater feedstocks for the proposed treatment facility should be fully understood. The specific wastewaters intended for this project will be derived from the processing of peaches, kiwis, apples and pears. The production of these four fruits represents over 9% of all crop based commodities in Greece, where this novel research is being carried out, demonstrating that a significant volume of associated wastewater will also be generated during processing (FAOSTAT, 2017). In general, all four wastewaters will be generated by similar means. An outline of their production is presented below, with stages producing potential wastewaters highlighted in orange (Figure 66).
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Deliverable 6.2 Figure 66: A proposed value chain for the general production of fruit waste waters during processing.
Whenever food, in any form, is handled, processed, packaged and stored there will always be an inherent generation of water. Therefore, Figure 66 commences at the beginning of the food processing chain with the cultivation and harvest of crops. Fruits are separated from unwanted, inedible fractions (i.e. stems and leaves) before being transported to appropriate processing facilities. No wastewaters are generated in this stage (Carawan, 1979). Upon arrival at the processing plant, fruits will be Figure 67: Flotation chamber for cleaning apples (OnApples, 2015) washed and rinsed by means of flumes, soak tanks, water sprays or flotation chambers (Figure 67). Significant quantities of water are used here. Fruits are then graded and sorted based on quality. In the cases of mechanical or manual handling, no additional water will be produced. Density graders however require liquids of known density to separate over-ripe produce from those of ideal maturity, thus generating extra wastewater. Cleaned and sorted fruit is then stemmed, clipped and trimmed, primarily by mechanical means (Carawan, 1979). Further processing will ensue, depending on the intended application of the fruit and there are various means of transporting fruits to their desired locations. For example, elevating, vibrating, screw conveying, air propulsion, fluming and hydraulic flows are such methods that can be used within processing facilities to transport fruit. Water has traditionally been used as an in-house method of transport due to its ability to simultaneously cool and further wash fruit. However, these methods generate substantial amounts of unnecessary wastewaters on top of the possibility of losing valuable soluble compounds from the materials (i.e. sugars and acids) (Carawan, 1979). The subsequent peeling of fruits serves the purpose of removing residual soils, pesticides or inedible skins by mechanical, thermal or chemical techniques. Hot water can be applied in thermal methods and liquid chemicals also present the possibility of being lost in wastewater streams. Pitting, coring, slicing and dicing are also common processing methods in fruit 92
Deliverable 6.2 preparation. Although these techniques primarily require mechanical technology and the external inputs of water are minimal, the generation and potential loss of juices can accumulate in wastewater streams. The same can be said for pureeing and juicing. After the initial preparation of fruit, produce will then be packaged in bags, pots or cans, which may be cleaned prior to filling to uphold hygiene standards, ultimately adding to wastewater streams (Carawan, 1979). To complete the value chain of processed fruits, packaged material will be transported to retail locations and sold to customers for consumption. These processes will not further contribute to wastewater streams. However, the end of production clean-up of process plants will add significantly to waste. Clean-up will begin with the collection of dry waste followed by a wash-down with water/detergent mixtures. In most food processing facilities, clean water is used to flush out entire systems to remove residues which may harbour bacterial growth (Carawan, 1979).
Wastewater Logistics It is important, when describing the pathway of a novel technology, to consider the logistical requirements of the system. In this case, the logistics will primarily involve the collection of wastewaters and their transportation to the novel AgroCycle treatment facility. The fruit processing industry generates large volumes of effluent, containing typically high organic loads, salts, suspended solids i.e. fibres and soil particles, cleansing agents, pesticide residues and other process chemicals (WorldBankGroup). A key requirement of the EU Urban Waste Water Directive is the “pre-authorisation of discharges from the food processing industry” i.e. food wastewaters need to meet specific requirements before they are disposed of (EuropeanCommission, 1991). Since fruit effluents contain high volumes of contaminants, it is therefore expected that commercial fruit processing facilities around Greece will have some form of wastewater treatment system integrated onsite. This will be the case for the novel AgroCycle treatment facility as the proposed pilot plant will be installed in a local fruit processing factory. Figure 68: A typical drainage system fitted within a food processing facility (ACO, 2016)
The associated fruit processing plant will use a combination of pumps and drainage for the effective diversion of waters from their point of source to the pilot plant. Figure 68 illustrates a typical drainage system used for collecting process waters and, via connected pipelines, effluents can then be transferred to the desired treatment location (ACO, 2016), which is normally located inside the property of the fruit processing facility.
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Deliverable 6.2
Wastewater Valorisation and Products The proposed AgroCycle technology aims to improve upon conventional methods of wastewater treatment by not only cleaning, but recovering useful materials from effluent. After the transfer of wastewater to the onsite pilot plant, the valorisation of wastes will begin. The novel AgroCycle treatment process will proceed via three main modular processes. However, since the primary objective of this project is to lower the economic and environmental footprints related to the processing of specifically liquid wastes, care will be taken to first separate the majority of the suspended matter (sludgy material) from the wastewater stream. Suspended solids management will therefore take place before the three treatment stages and will employ conventional primary wastewater treatment techniques (i.e. sedimentation, filtration or centrifugation), to remove suspended solids from the coveted liquid stream. The sludge obtained will display relatively high concentrations of solids, but water content is also high. Sludge will therefore require thickening to a solid concentration of around 20% so they can then be handled as solids. Thickened sludge can then be treated through conventional waste sludge management processes such as anaerobic digestion and composting for example (UNEP, 2017), together with the excess sludge originating from AD and MBR wastewater treatment. Once sludge is removed, the treatment of wastewaters will proceed. The wastewater streams generated in the processing of fruits are ideal substrates for the growth of unicellular yeast species, due to characteristically high concentrations of dissolved natural sugars. Furthermore, this will be an aerobic system as the addition of oxygen will further aid yeast cultivation in the wastewater. The initial treatment stage in the novel AgroCycle process aims to optimise conditions for the growth of these micro-organisms which are known for their ability in producing single-cell protein (SCP). SCP may be used primarily as protein replacements in both human and animal nutrition. However, the specific yeast variety exploited in this process, the Yarrowia lipolytica species, is also recognized for its capacity in generating other value-added compounds such as biolipids that further enhance its properties as a fodder supplement. Membranes, will be tested to recover such compounds, thus allowing significant value to be gained from wastewaters of otherwise little worth. Anaerobic digestion (AD) will be employed in the second stage to further treat wastewaters. The generation of biogas in this stage is considered a useful by-product of the process. However, due to only small volumes of organic matter in the wastewater, much smaller quantities of biogas will be recovered when compared to the digestion of AD feedstocks with higher solids content. Nevertheless, it is worth remembering that the primary goal of the overall process is to improve the economic and environmental footprint of conventional wastewater treatment. The use of AD at this stage therefore aims to primarily reduce organic matter and pathogen content in water, the generation of biogas is an added benefit. As a result, the biogas quantities obtained here are not of concern as the production of clean water, with reduced energetic and environmental footprint, is the main objective.
Anaerobic digestion wastewaters will then be directed to a final treatment stage, using membrane bioreactor (MBR) technology to clean-up effluents. Error! Not a valid bookmark self-reference. demonstrates how this technique works. Like the first stage outlined in the overall AgroCycle process, this final stage is also aerobic, meaning that oxygen is required to sustain biological activity in the system. Waters will first flow into the bioreactor where microorganisms act to break down residual organic matter in the water. Membranes, displaying pore sizes
