SOLID WASTE MANAGEMENT ALTERNATIVE SCENARIOS IN WESTERN MACEDONIA (KOZANI), GREECE K. Kechagia1, A. Tselepi, E. Darakas, A. Zafirakou, S. Bayouk Division of Hydraulics and Environmental Engineering, Dept. of Civil Engineering, Aristotle University of Thessaloniki, GR- 54124 Thessaloniki, Macedonia, Greece 1 E-mail:
[email protected] ABSTRACT In the present study the Integrated Waste Management System (IWMS) in the Region of Western Macedonia, and particularly in the Municipality of Kozani, is being examined. The current situation is herein portrayed with regards to the solid waste collection, transfer, transhipment and disposal to the landfill of Western Macedonia in the period 2006-2010. In addition to this, the Regional Recycling System, whose implementation methodology is based on a sorting system in source, has been evaluated. It has been revealed that, from the total quantity of mixed and recyclable municipal solid waste, only 6.0% is recycled. Given that the current legislation in Greece proposes the pre-treatment of the total solid waste load produced before entering the landfill, in order to reduce the volume of solid waste as well as recover materials and energy from waste, four possible options of treatment methods have been presented and compared. The four treatment methods under investigation are: production and incineration of RDF (Refuse Derived Fuel), production and incineration of SRF (Solid Recovered Fuel), anaerobic digestion and biogas production, and incineration. The option of anaerobic digestion and biogas production was finally selected and cost-estimated, in regards to lower environmental and financial burdens for the recipients. Conclusively, the total management cost of the municipal solid waste for the area with the implementation of the proposed scenario is quite high, but the suggested treatment method prolongs the life of the landfill by the year 2024. Keywords Solid waste management; recycling; energy recovery; incineration; anaerobic digestion;
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1. INTRODUCTION 1.1 Description of the current situation in the study area The Integrated Waste Management System (IWMS) in the Region of Western Macedonia, Greece, serves approximately 300.000 inhabitants which are distributed at sixty one (61) municipalities in the prefectures of Kozani, Grevena, Kastoria and Florina. The system includes the landfill site and the network of the local waste management units, in which the Waste Transfer Station (WTS) have already been constructed. The system is based on the operation of ten WTS, which are divided into three main (Kozani, Kastoria and Ptolemaida) and seven sub-main stations which are characterized as satellite WTS (Map 1). The total amount of Municipal Solid Waste (MSW) produced per year which requires management approaches 120.000 tons. A percentage of 55% is generated in the five largest municipalities, which are Kozani, Ptolemaida, Kastoria, Grevena and Florina and the remaining 45%, which do not exceed 900 tons per year is paid to the other municipalities (DIADYMA SA, 2010).
MAP 1. The study area (Western Macedonia, Greece), (DIADYMA SA, 2010) The IWMS includes the collection, transportation, transfer, recovery of useful materials through recycling and the landfilling of the residue solid waste. It also includes the management of specific solid waste, taking into account the mechanical treatment and the recovery and utilization of materials included in the MSW. The operators’ administrators for the whole system are the municipalities and the company “DIADYMA SA”, which is the Association of the sixty one local authorities dealing with the management of MSW in the area of Western Macedonia. Specifically, the municipality of Kozani is responsible for the collection and the transportation of MSW to the WTS of Kozani, which is a supra WTS, while “DIADYMA SA” implements the transshipment and the final disposal (landfilling) of the MSW. The operators in the city of Kozani are collecting MSW in temporary storage bins. They have about 1000 storage bins of 1100 lt capacity, which are used only for the mixed solid waste, not for the recyclable materials. A preliminary separation of the MSW is taking place depending on their properties. In the surrounding districts of the city, about 850 storage bins with different capacities, i.e. 360, 660 and 1100 lt, are 2
used. Regarding the recyclable materials such as paper, glass and aluminum, the municipality of Kozani disposes 53 bins for paper, 53 bins for glass and 48 bins for aluminum, while the surrounding districts of the city disposes 29 bins for paper, 3 bins for glass and 6 bins for aluminum (Municipality of Kozani, 2009). The recycling is done by sorting at source. The transportation of the mixed MSW is done by garbage-type mill and press trucks, while the transportation of the recyclable materials is done by open trucks which are specially modified i.e. equipped with different body compartments. From the WTS the MSW of Kozani are transported to the Central Installation of Integrated Management. This central installation is located in the area of the Western Macedonia landfill site, very close to the Regional Recycling Center (RRC) (Map 1). The landfill site covers an area of 327.000 m2. Its capacity is ca 120.000 tons/year. Landfilling is done in two rectangular basins with a capacity of 600.000 m3. The infrastructure includes the sealed cells with a capacity of about 1.300.000 m3 (cell A and cell B in total), facilities for the biological treatment of the leachates, a system for the controlled combustion of the landfill-gas, the stormwater management works, the fire zone, building infrastructure at the entrance of the complex and the internal road network. At the Regional Recycling Center the final sorting, the baling and the collection of the recyclables from the relevant companies dealing with this issue, are taking place. 1.2 A scientific approach to MSW management scenarios The Joint Ministerial Decision (JMD) 114218/1997 establishes a framework of technical specifications and of general plans of Solid Waste Management (SWM). It determines the technical specifications regarding the appropriate systems, means and procedures for each of the available waste treatment methods, like temporary storage, collection and disposal, collection at source, recycling e.t.c. It also specifies the criteria for the selection of landfills, as well as for the planning, design and function of sanitary legal waste disposal sites, mechanical sorting plants and composting facilities. Specifications on compost products are also included. Through the JMD 29407/3508/2002, which deals with measures and terms for landfilling of waste, the Directive 99/31/EC on the landfill of waste, was applied to the Greek legislative framework. The legislation requires the recovery of waste materials and the restoration of the productive cycle. The legislation imposes the minimization of the impact of the landfilling and provides guidelines for reducing the wastes to be landfilled. It requires that the landfills will gradually be turned into residue landfills. The main elements introduced with the JMD are: Waste must be treated before landfilling (mass and volume reduce) Stricter operational rules must be taken for sanitary landfills Changes regarding gate fee for landfilling were introduced Requirements for the landfill operating authorities were established Planning and permitting procedure were changed. Those requirements aim to promote the construction of high standard landfills which will gradually be turned into residue landfills. Regarding gate fee, costs of financial security, final closure and after-care have to be included. Moreover, article 12 of JMD 29407 requires that the costs for operation and extension works of landfills will be covered by the price charged by the waste management authorities (via Municipalities) for the disposal of waste. The design of alternative scenarios for integrated management of MSW must be based on the following: Preference to energy recovery; energy is a readily marketable "product" leading to profit Configuration scripts to the lowest investment - operating costs 3
Consideration of commercial units dealing with the management of mixed MSW without any serious environmental impact. For this reason, pyrolysis and gasification are not considered, as their application to mixed MSW is not highly developed in our country Preference to scenarios aiming at significant reduction of the total volume of MSW to be handled. The scenarios considered are the following: Production and combustion of Refused Derived Fuel (RDF); a method based on mechanical sorting of MSW, production of compost and RDF, which can be utilized in the energy unit. RDF consists largely of organic components of MSW such as plastics and biodegradable waste. RDF processing facilities are normally located near a source of MSW and, while an optional combustion facility is normally close to the processing facility, it may also be located at a remote location. RDF can be used in a variety of ways to produce electricity. It can be used in conjunction with traditional sources of fuel in coal power plants. Production and combustion of Solid Recovered Fuel (SRF); a method based on drying, producing and burning a stabilized product. SRF can be distinguished from RDF by the fact that it is produced to reach a standard. Construction and operation of waste to energy plants are expected to enhance demand and thus selling price significantly. Production and combustion of biogas (Anaerobic Digestion); a method based on mechanical processing (extended hand-sorting and mechanical sorting), anaerobic treatment of the organic fraction for biogas production and use thereof in a power plant, as well as further maturing of the residue of the anaerobic digestion to produce a coating material. Incineration of the total mixed MSW including the type mass-fired, leading to energy recovery. A few years ago the waste management authorities in the region of Attica issued a market study in order to find a way to utilize the RDF produced in the Athens treatment unit. The study included two big cement industries and other types of industry where big amounts of energy are required but there was no correspondence. The industries put some special requirements and specifications such as moisture and chlorine content, low bulk density, and high calorific value, regarding the characteristics of the RDF in order to accept it as a fuel. Some of the issues brought to the table by the industry like low facility performance, odor emissions while handling RDF which might affect personnel, need of storage capacity, RDF production rate, modification of the facility’s environmental permission terms, should be examined closely and solutions should be provided. Assuming that the RDF qualitative requirements are met, the acceptance of RDF will be highly expected, since the interest in using alternative fuels is constantly increasing. Between a cement industry and the waste management authorities a contract has been signed, which states that initially 35.000 tn/year will be co-incinerated in the cement industry and that amount will increase to 75.000 tn/year. According to the contract, the cement industry will receive 10 €/tn of RDF co-incinerated. A total of 750.000 €/year will be required, while for less amount the price could reach 20 €/tn. The contract was signed in February 2007 and has a five-year duration. Nevertheless the total amount of RDF is still being landfilled (Euroconsultants, EPTA, 2010). Considering that the anaerobic digestion with biogas production is an environmentally and economically advantageous method, we made some efforts to estimate the cost of such an investment as a part of the IWMS, compared with the current situation. 2. RESULTS AND DISCUSSION 2.1 Facts and data concerning the management of MSW in Kozani 4
Based on the existing treatment technologies for MSW and the information provided by the relevant authorities in the municipality of Kozani and DIADYMA SA, we examined different possible scenarios of treatment for the total MSW generated in the study area of Western Macedonia. We collected and processed the quantitative and the qualitative data of MSW generated in the city of Kozani in the period 2006 - 2010. The average annual and daily production of MSW per capita was calculated. Moreover, we processed and calculated the amount of the recyclable materials and their proportion to the total amount of MSW. The results are shown in figures 2.1.1 and 2.1.2.
FIGURE 2.1.1. Quantities (%) MSW per Waste Transfer Station
FIGURE 2.1.2. Generation of MSW in the city of Kozani Figure 2.1.2 shows that the annual average generation of MSW for the period 2006 – 2010 is 24.396 tons (DIADYMA SA, 2010). The annual output per person is 514 kg while the daily output per capita is 1,4 Kg/person/day. The composition of the MSW from a sample of 120.000 tn/year, i.e. the total amount of the MSW ending to the landfill, is presented in table 2.1.1. 5
TABLE 2.1.1. Composition of the MSW at the landfill (DIADYMA SA, 2010) Main categories Organics Paper
Plastic
Metals
Glass
% 53,90 14,20
Sub-categories
%
Cardboard Newspapers, Printed paper Books White paper Tetrapack Other paper
6,07 3,35 1,00 0,36 0,71 2,71
Plastic bottles (ΡΕΤ) Plastic bottles (ΡΕ) Plastic film Other plastic
3,16 1,91 1,91 6,32
Aluminum Tinplate metals Other metals
0,65 1,36 2,01
Glass packaging Other glass
1,24 0,41
13,30
4,02
1,65
Leather, Wood, Textile material, Rubber 4,31 Inert materials 4,31 Others 4,31 TOTAL 100,00 Regarding the recyclable materials we found that the annual generation of paper is 1.384 tn, the generation of glass is 21,5 tn and the generation of aluminum is 2,2 tn. The percentage of recyclable materials is just 6,0%, compared to the total quantity of MSW generated. Given the (qualitative) composition and the total amount of the MSW generated per year, we estimated the energy recovered by applying the alternative scenarios discussed above. The high calorific values are based on the literature (Juniper, 2005). The results are presented in table 2.1.2. Furthermore, based on the relatively low cost, the minor environmental impact and the experience in the construction of anaerobic digesters since 2002, we focused on the scenario of the anaerobic digestion - production and combustion of biogas, making some efforts to estimate its cost. According to this scenario, the residue to be driven to the landfill will be 71.445 tn/year, making the following assumptions: - the plant will be in operation in year 2013 - the usable volume of the landfill (for the residues) will be equal to 380.000 m3 in January 2013 - the compression rate will be 0,85 ton/m3 - the amount of the daily covering material will be 15,0% v/v in relation to the residues.
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TABLE 2.1.2. Alternative scenarios for the IWMS and energy recovery Treatment method
Composition (Material)
Percentage (%) in the mass of the MSW (DIADYMA SA, 2010)
Fuel (Tn/year) (Energy for exploitation)
High calorific value (MJ/kg) (Juniper, 2005) 15
Energy recovery MW
Production and combustion of RDF
Paper, Plastic, Leather, Wood, Textile material, Rubber
14,2% + 13,3% + 4,3% = 31,8%
31,8% x 120.000 = 38.160 tn RDF / year
Production and combustion of SRF
Organics, Paper, Plastic, Wood, Textile material, Rubber
60% (53,9%+ 14,2% + 13,3% + 4,31%) = 51,43%
51,4% x 120.000 = 61.711 tn SRF / year
18
35,22 MW 6,64 MW for internal use 28,58MW to sell
Incineration of the MSW
Total mass of MSW
100%
120.000 tn/year
10
38,05 MW 7,90 MW for internal use 30,14 MW to sell
Production and combustion of biogas
Organics
53,9% x 120.000 = 64.680 tn/year
6.468.000 m3
6.468.000 m3 x 5,5 KWh/ m3=4,94 MW
4,94 MW 1,98 MW for internal use 2,92 MW to sell
18,15MW 3,43 MW for internal use 14,72 MW to sell
TABLE 2.1.3. Alternative scenarios and costs (investment and operation) Aggregate Financial Data Investment (million €) Operation (million €)*
Production and combustion of RDF
Production and combustion of SRF
Production and combustion of biogas
Incineration of the MSW
59
59
36
77
37
41
23
7,5
*The operation cost is a net cost. The profit from the sale of energy generated for each technology has already been removed. 7
Furthermore, we estimated that the landfill site for the residues will extend its life for four years. Given that an expansion to 640.000 m3 of the landfill site is planned and the total available volume for the residues will rise to 1.063.270 m3, we estimated a sufficient extension of its life for seven years (Table 2.1.4). TABLE 2.1.4. Waste to be landfilled after treatment (Starting year 2013) Year
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
tn/year
71.445
Compression Annual (tn/m3) volume of the residues (m3)
0,85
84.053
Cover material (m3)
12.608
Total volume (m3)
96.661
Total landfill volume (m3) 96.661 193.322 289.983 386.644 483.305 579.965 676.626 773.287 869.948 966.609 1.063.270 1.159.931 1.256.592 1.353.252 1.449.913
2.2 Calculations of the cost management based on the analyzed scenario Table 2.2.1 shows the MSW Management cost for the municipality of Kozani based on year 2010. During this year 26.060 tons of MSW were generated in the municipally. The amount of 703.000 € refers to the integrated management of solid waste which is currently being implemented. Accordingly, this amount should be deducted in case of the proposed scenario. So the final cost for the collection and the transportation of the MSW to the plant will be specified to 3.111.000 €/year or 119,4 €/tn. TABLE 2.2.1. MSW Management cost for the municipality of Kozani (year 2010) MSW Management costs € % Payroll staff 2.758.000 72,3 Fuels / Lubricants 130.000 3,4 Services / Insurance 130.000 3,4 Overheads (Different expenses) 50.000 1,3 Leasing of equipment 43.000 1,1 Transshipment / Landfilling 703.000 18,5 TOTAL 3.814.000 100,0 8
Then we estimated the cost for transshipment of the MSW. This cost, which amounts to 8,5 €/tn, is analyzed and presented in Table 2.2.2. TABLE 2.2.2. Estimation of the transshipment cost Net truck load 20 tn Routs (26.060 tn / 20) x 2 = 2.606 routs Distance between WTS station and landfill 20 km Total kilometers traveled by trucks per year 2.606 x 20 = 52.120 km Fuels / Lubricants / Services 1,3 €/km Annual expenditure on fuel and services 1,3 €/km x 52.120 km/year = 67.756 €/year Drivers cost 30.000 €/year Guards (4 persons) 4 x 23.000 €/person/year = 92.000 €/year Other operational cost 30.000 €/year Annual cost for transshipment 219.756 €/year Expense for transshipment per ton MSW (219.756 €/year)/(26.060 tn /year) = 8,5 €/tn The treatment cost includes investment and operating costs, which accounts for 9.500.000 € for civil engineering projects, 22.000.000 € for electrical engineering projects, 500.000 € for other equipment / infrastructure and 4.800.000 € for general expenses / overheads. The total investment for the treatment amounts to 36.800.000 €. Assuming that the damping of the investment fund will take 10 years, we lead to the conclusion that the final cost will be 3.680.000 €/year or 31 €/tn, based on a total amount of 120.000 tons MSW/year. Concerning the operation cost we accounted for the personnel required 297.000 €/year, 907.200 €/year for the maintenance and the service and 1.536.000 €/year for the hand-sorting of MSW, the total operation cost amounts to 2.740.200 €/year or 22,84 €/tn. Finally the total treatment cost including investment and operating amounts to 54,0 €/tn. We took into account the benefits from the exploitation of the energy produced from the biogas and the recyclables produced in both the unit and the system of sorting at source. Subtracting the cost of transshipment from the total cost for the transshipment and disposal in the landfill raises the final cost of disposal. This amounts to 23 €/ton. Finally, adding the collection (119,4 €/tn), the transshipment (8,5 €/tn), the treatment (54,0 €/tn) and the final disposal (23,0 €/tn) cost, we can anticipate that the total cost for the analyzed scenario amounts to 205 €/tn MSW or 112 €/capita/year. 3. CONCLUSIONS It was found that there is adequate equipment, experience and desire to achieve the objectives for an Integrated Waste Management System in the region of Western Macedonia. All stages including the collection, the temporary storage, the transshipment and the disposal run smoothly. The time and the transportation cost have been reduced while the productivity of the staff is remarkable during the last years. After processing the data, we realized that the recyclables recovered cannot be more than 6,0 %. This percentage is very low compared with the targets set by the legislation. However, we should not underestimate the efforts that are made for recycling, which even they represent a very low percentage of the total MSW they contribute to huge environmental benefits. The total cost of the MSW current management amounts to 151 €/tn or 83 €/capita/year. By applying the scenario of anaerobic digestion and biogas production, which is presented above, the total cost of MSW management will reach 205 €/tn or 112 €/capita/year. This cost is too high; 9
however, it is resulting in a reduction of the quantities of MSW and extends the life of the landfill, specifically after the planned expansion, until year 2024. A significant increase in the efficiency of the analyzed scenario can be achieved in the future, through the implementation of a program aiming to a better sorting of MSW at source, including the organics generated at home. Co-digestion of sewage sludge from the Wastewater Treatment Plants in the area along with livestock waste could increase biogas production and energy recovery. REFERENCES 1. DIADYMA SA, (2010), Integrated Solid Waste Management in Western Macedonia, (Operation years 2009 – 2010), Final report, Kozani 2. Municipality of Kozani, (2009), Report on Municipal Solid Waste Management, Division for Waste Management, Kozani 3. European Topic Center on Waste, Biodegradable municipal waste management in Europe, European Environmental Agency, http://scp.eionet.europa.eu/, (accessed March, 2011) 4. Official Journal of the European Communities, (1999), Landfill Directive 1999/31/EC, L182, 16.7.1999 5. Hellenic Solid Waste Management Association, The Legislative Framework for the Management of MSW in Greece, http://www.eedsa.gr, (accessed March, 2011) 6. Juniper Consultancy Services Ltd., (2005). Mechanical-Biological-Treatment: A Guide for Decision Makers Processes, Policies and Markets, http://www.juniper.co.uk/publications, (accessed March, 2011) 7. Euroconsultants, EPTA, (March 2010), Joint European Support for Sustainable Investment in City Areas “JESSICA”, Instruments for Solid Waste Management in Greece, Final report – Part 1 8. Tchobanoglous, G., Theisen, H. & Vigil, S., (1993), Integrated Solid Waste Management, Mc Graw - Hill. Inc., USA 9. United States Environmental Protection Agency, Wastes, http://www.epa.gov/epawaste/index.htm, (accessed Feb, 2011) 10. Ministry of the Environment, Legislation, http://www.minenv.gr/4/g401.htm, (accessed Feb, 2011).
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