full report - IEA Bioenergy Task 32

International Energy Agency Bioenergy Agreement Task 32 Biomass Combustion and Cofiring

Working Group Meeting Arranged by: Sjaak van Loo and Jaap Koppejan TNO-MEP, the Netherlands

Content: Minutes of the 2nd Task Meeting, Working Group Meeting-Biomass Combustion and Cofiring

June 19-20, 2002 RAI Conference Centre Amsterdam, Netherlands

IEA Working Group Meeting Task 32 Biomass Combustion and Cofiring June 19-20, 2002, Amsterdam, Netherlands

Table of contents Programme Attendance list Summary of the meeting Wednesday June 19, meeting part 1 Opening, news from IEA ExCo Report of last meeting Distribution and follow-up of Handbook Need for a separate task on cofiring New or revised task proposals Combustion and co-firing network of excellence (Sjaak van Loo) Status of CHP overview (Ingwald Obernberger) Internet site and database on biomass fuel, ash and condensate (Jaap Koppejan/Ingwald Obernberger) Thursday June 20: Task meeting Part 2 Country presentations Next meetings and workshops (Sjaak van Loo) Cofiring seminar (part of main conference) Future actions

2

Annexes Annex 1. Waste wood combustion (task proposal, Claes Tullin) Annex 2. Inventory of cofiring experiences word-wide (task proposal, Jaap Koppejan / Sjaak van Loo) Annex 3. Comparison, validation and assessment of methods for the determination of the annual efficiency of biomass-fired district heating plants (Task proposal, Thomas Nussbaumer) Annex 4. Stoichiometry Effects on Corrosion during Cofiring (Task proposal, Larry Baxter) Annex 5. Formation of Striated Flows During Biomass-coal Cofiring (Task proposal, Larry Baxter) Annex 6. Biomass Impacts on SCR Catalyst Performance (Task proposal, Larry Baxter) Annex 7. Combustion and co-firing network of excellence Annex 8. Decentralised CHP technologies based on Biomass Combustion (Task activity), Ingwald Obernberger Annex 9. Internet site (Jaap Koppejan) Annex 10. Country report – Austria, Ingwald Obernberger Annex 11. Country report – Netherlands, by Ad van Dongen (Reliant Energy, NL) Annex 12. Country report – USA, by Larry Baxter Annex 13. Country report - Norway, by Øyvind Skreiberg Annex 14. Country report – Switzerland, by Thomas Nussbaumer Annex 15. Aerosols from Biomass Combustion –Overview on Activities in IEA Bioenergy Task 32 T. Nussbaumer and S. van Loo Annex 16. Nanoparticle Emissions of Novel Wood Combustion Processes C. Gaegauf, U. Wieser, R. Hermansson, V.-P. Heiskanen Annex 17. Fuel Staging for NOx Reduction in Biomass Combustion: Experiments and Modeling Roger Salzmann, Thomas Nussbaumer Annex 18. Quality Assurance for Planning and Construction of Biomass District Heating Plants R. Bühler, H.R. Gabathuler, J. Good, A. Jenni

3

Programme Wednesday June 19: Task meeting Part 1 9:00

Opening, news from IEA (Sjaak van Loo)

9:15

Report of last meeting (Sjaak van Loo)

9:30

Distribution and follow-up of Handbook (Sjaak van Loo)

10:00

Need for a separate task on cofiring (Sjaak van Loo)

10:20

Coffee break

10:45

New or revised task proposals: - Activities on waste wood combustion (Claes Tullin) - Overview of cofiring experiences (Jaap Koppejan) - Methods for determination of annual efficiency (Thomas Nussbaumer) - 3 proposals related to biomass cofiring (Larry Baxter)

12:45

Lunch

13:30

Combustion and co-firing network of excellence (Sjaak van Loo)

14:15

Status of CHP overview (Ingwald Obernberger)

14:45

Internet site and database on biomass fuel, ash and condensate (Jaap Koppejan/Ingwald Obernberger)

15:15

End of day 1

19:00

Conference dinner

Thursday June 20: Task meeting Part 2 9:00

Country presentations (All)

10:20

Coffee break

10:45

Country presentations (All)

11:10

Next meetings and workshops (Sjaak van Loo)

14:30

Cofiring seminar (part of main conference)

4

Attendance list Representatives Ms. Garbine Guiu (Task member) European Commission DG for Science Research and Development Rue de la Loi, 200 B-1049 BRUSSELS Belgium tel +32 2 2990538 fax +32 2 2993694 [email protected]

Richard Logie (Task member) Department of Natural Resources Renewable Energy Technology Group Energy Technology Branch 580 Booth Street 7th floor Ottawa, Ontario K1A OE4 Canada tel. +1 613 9950283 Fax +1 613 9969416 email [email protected]

Peter Costelloe (Alternate Task member) Technical Services Manager C.S. Energy Swanbank Power Station MS 460 Qld 4306 Ipswich Australia tel +61 7 3810 8802 fax +61 7 3810 8777 [email protected]

Jesper Werling (alternate Task member) dk-TEKNIK Gladsaxe Mollevej 15 DK-2860 SOBORG Denmark tel +45 39 555999 fax +45 39 696002 [email protected] Sjaak van Loo (Task leader) TNO-MEP P.O. Box 342 7300 AH APELDOORN Netherlands tel +31 55 5493745 fax +31 55 5493740 [email protected]

Ingwald Obernberger (Task member) Institute of Chemical Engineering Fundamentals and Plant Engineering Technical University of Graz Inffeldgasse 25 A - 8010 GRAZ Austria tel +43 316 481300 fax +43 316 4813004 [email protected]

Øyvind Skreiberg, Ph.D. (Task member) Research Scientist Department of Energy and Process Engineering Faculty of Engineering Science and Technology NTNU, N-7491 Trondheim Norway tel +47 73 592970 fax +47 73 598390 [email protected]

Jerome Delcarte (Alternate task member) Département de Génie Rural Centre de Recherche Agronomiques Chaussée de Namur, 146 B 5030 Gembloux tel. +32 81 61 2501 fax +32 81 61 5847 [email protected]

5

William R. Livingston (Task member) Group leader - fuel technology Mitsui Babcock Energy Limited Technology Centre High Street Renfrew PA4 8UW Scotland, UK tel +44 141 8862201 fax +44 141 8853370 [email protected]

Claes Tullin (Task member) Swedish National Testing and Research Institute Box 857 S-501 15 BORAS Sweden tel +46 33 16 5555 fax +46 33 131979 [email protected] Thomas Nussbaumer (Task member) VERENUM Langmauerstrasse 109 CH-8006 ZÜRICH Switzerland tel +41 1 3641412 fax +41 1 3641421 [email protected]

Larry Baxter (Task member) Brigham Young University Professor, Chemical Engineering JJ Christensen Professorship of Thermochemical Science 350 Clyde Building Provo, UT 84602 tel: +1 (801) 422-8616 fax: +1 (801) 422-7799 email: [email protected]

Observers: Jaap Koppejan (Secretary) TNO-MEP P.O. Box 342 7300 AH APELDOORN Netherlands tel +31 55 5493167 fax +31 55 5493740 [email protected]

Søren Houmøller dk-TEKNIK Gladsaxe Mollevej 15 DK-2860 SOBORG Denmark tel +45 39 555999 fax +45 39 696002 [email protected]

Ad van Dongen senior stafmedewerker Reliant Energy Power Generation Benelux BV Postbus 8475 3503 RL Utrecht Netherlands tel +31 30 - 247 2853 fax +31 30 247 22 55 [email protected]

6

Absent: Peter Coombes (Task member, substituted by Peter Costelloe) Business Development Analyst Delta Electricity Level 12, Darling Park 201 Sussex Street Sydney 2000 Australia tel: +61 2 9285 2789 fax: +61 2 9285 2780 [email protected]

Heikki Oravainen, (Task member) senior research scientist VTT Energy, Fuels and Combustion P.O. Box 1603 FIN-40101 Jyväskylä Finland tel +358 14 672532 fax +358 14 672596 [email protected] Kees Kwant (Operating Agent) NOVEM P.O. Box 8242 3503 RE UTRECHT Netherlands tel +31 30 2393458 fax +31 30 2316491 [email protected]

Yves Schenkel (Task member, substituted by Jerome Delcarte) Département de Génie Rural Centre de Recherche Agronomiques Chaussée de Namur, 146 B 5030 Gembloux tel. +32 81 61 2501 fax +32 81 61 5847 [email protected]

John Gifford (Task member) Forest Research Institute Private Bag 3020 ROTORUA New Zealand tel +64-7-343-5899 fax +64-7-343-5507 [email protected]

Henrik Houmann Jakobsen (Task member, substituted by Jesper Werling) dk-TEKNIK Gladsaxe Mollevej 15 DK-2860 SOBORG Denmark tel +45 39 555999 fax +45 39 696002 [email protected]

7

Summary of the meeting Wednesday June 19, meeting part 1 Opening, news from IEA ExCo The second meeting of Task 32 was held June 19-20 in the RAI Conference centre and coincided with the 12th European Conferences & Technology Exhibition on Biomass for Energy, Industry and Climate Protection. The meeting was chaired by Sjaak van Loo (Task leader). Due to national funding constraints for participation in IEA Bioenergy activities, a number of Task members were represented by colleagues at the meeting. Twelve out of fourteen member countries were represented at the meeting. Sjaak van Loo opened the meeting welcoming all participants to Amsterdam. An earlier Task meeting scheduled for November 19-21 in Jyväskylä, Finland organised by Heikki Oravainnen (VTT) regretfully had to be cancelled a week in advance due to a lack of interest. It was concluded that this was partly due to the situation after September 11, 2001. It is a general observation from both IEA Headquarters and the ExCo of IEA Bioenergy that measurable deliverables of the individual Tasks are often lacking. This is needed to keep going with declining national budgets. It was argued by Task 32 that also the in future we should continue to provide tangible results, such as the Handbook on Biomass Combustion, a database on fuel and ash composition on the internet, workshops, etc.

Report of last meeting The report of the first Task meeting was approved by the task members without further comments. Comments on the draft version were already incorporated before.

Distribution and follow-up of Handbook The Handbook on Biomass Combustion and Cofiring was finally presented at the 12th European Conferences & Technology Exhibition on Biomass for Energy, Industry and Climate Protection. Promotion materials (leaflets, posters) were prepared to attract attention during the Conference and an introductory offer was made (39 €, normal price 44€). While the first draft of the manuscript was prepared in 2000, based on a State of the Art Overview on Biomass Combustion (a document translated from Dutch to English), the final version of the book was significantly upgraded using the contributions of all task members and contains an in-depth overview of all relevant issues, varying from domestic woodstoves to the latest co-firing experiments. All task members will receive a box with 15 copies for free for internal distribution, additional copies can be ordered through the task internet site.

Need for a separate task on cofiring An important question put forward by the ExCo to the members of Task 32 is whether or not it would make sense to split Task 32 into two separate tasks on Combustion and Cofiring.

8

After a brief discussion it was argued by the members on Task 32 that separating the current task would not be preferable for a number of reasons: - Not all countries would participate in both tasks, therefore less members would provide input to either activities. At least Canada, Sweden and Switzerland would not be able to participate in a separate task on cofiring. - There are no scientific or technical differences between combustion and cofiring. With biomass combustion applications varying from woodstoves to industrial boilers and coal power plants, the main difference is the size range. - If member countries would feel that one of both topics would need more attention, it could be considered to appoint other representatives in the task. Further it is considered important that we continue to identify options for cooperation with other tasks, such as the Amsterdam cofiring seminar (together with Task 33), another cofiring seminar at the next task meeting in Clearwater, USA and a seminar with Tasks 33 and 36 on waste wood combustion (Japan, Autumn 2003).

New or revised task proposals Six new proposals were presented on task-funded activities. Detailed descriptions of the above proposals are enclosed in Annex 1 to Annex 3. These are: - Activities on waste wood combustion (Claes Tullin, see Annex 1) In this proposal it is suggested to either compile a report with results of different R&D projects on waste wood combustion, or organise an international workshop on experiences with combustion of waste wood. It was agreed to organise such a workshop in conjunction with the final meeting of Task 32 in Japan, autumn 2003 with support from Task 32. Topics to be covered in the workshop could include o Utilization of contaminated wood o Technologies o Waste wood classification o Emission guidelines (EU Waste Incineration Directive and EU Large Combustion Plants) o Experiences with wastewood combustion plants o Aerosols - Overview of cofiring experiences (Jaap Koppejan, see Annex 2) This proposal was made after a strong suggestion from the ExCo 48 that it would be very valuable if Task 32 could prepare an overview of cofiring experiences world-wide, similar to the currently prepared overview of experiences with biomass fired CHP plants (Task activity by Obernberger). It was agreed to perform this activity. As a start, a data format will be first agreed upon, after which all will be asked to come up with reports, data etc. that can be used to fill in the formats. As the budget does not allow an in-depth study on each initiative, the overview will be a plain description of the initiatives, without a critical review of every initiative. - Comparison, validation and assessment of methods for the determination of the annual efficiency of biomass-fired district heating plants and Assessment of methods for boiler efficiency and measures for efficiency improvement (Thomas Nussbaumer, see Annex 3). During the task meeting no general agreement was reached on the need for implementing this study. However, as two countries not present at the meeting showed a positive

9

-

response afterwards, execution of this proposal was later suggested to Thomas Nussbaumer by Sjaak van Loo. Three proposals from Larry Baxter: Stoichiometry Effects on Corrosion during Cofiring (see Annex 4). Formation of Striated Flows During Biomass-coal Cofiring (see Annex 5) Biomass Impacts on SCR Catalyst Performance (see Annex 6) Task members are asked to consider participation in either of these proposals individually by contacting suitable coal fired power plants.

Combustion and co-firing network of excellence (Sjaak van Loo) 14 Dec 2001 a proposal was submitted by TNO to the European Commission for the establishment of an EU-wide forum for exchange of knowledge on biomass combustion and co-firing. This forum, with 17 partners containing all European participants in Task 32 and others, should provide manufacturing industry, end-users, governmental authorities, EU and national RTD Programme leaders and R&D organisations and universities with ideas, knowledge, tools, latest research results and experiences on this topic. Regretfully, the proposal was not accepted. June 7, 2002 an expression of interest has been submitted to the Commission by approx. the same consortium on the formation of a Network of Excellence on the same topic. It would be desired to prepare a proposal together with Pyne and Gasnet. See Annex 7 for the overhead sheets presented at the task meeting.

Status of CHP overview (Ingwald Obernberger) This task activity was accepted at the start of Task 32 (dec 2000) and consists of the production of a technological overview of innovative decentralised biomass CHP technologies and demonstration projects. Factsheets will be produced for biomass CHP plants with a description of the concept, costs and performance. The documentation produced is based on data from national demonstration activities, such as: - New steam turbine systems for small-scale applications (if available), - the new steam engine with oil-free operation, - the steam screw-type engine, - ORC systems, - Stirling engine systems, - new technological approaches regarding gas turbine processes. In his presentation (see Annex 8), Ingwald Obernberger showed an analysis of three demonstration projects that have already been evaluated in the framework of this activity: - EU demonstration project wit ORC (1000 kWe, Lienz, Austria) - Stirling engine demonstration projects (Joanneum Research Graz, TU Copenhagen) - New gas turbine technology with innovative recuperative heat exchanger (Pebble Heater) A detailed technological description of the above initiatives was done in the country presentation on Thursday June 20, see also Annex 10. Additional data is asked from all task members on new biomass fired CHP plants up to 5 MWe. For this purpose, Ingwald Obernberger will distribute a format with the type of information wanted.

10

Internet site and database on biomass fuel, ash and condensate (Jaap Koppejan/Ingwald Obernberger) Jaap Koppejan showed the progress made on the internet site (see Annex 9). Since the previous meeting, the following topics have been added: - The modelling spreadsheet Fuelsim Average (by Øyvind Skreiberg) - Databases on composition of biomass fuels, ashes and condensates (supplied in Excel by Ingwald Obernberger, converted into HTML by TNO) - An overview of issues related to biomass combustion and cofiring (the Task 32 brochure) - Information on the Handbook The number of visitors to the internet site steadily increases, in June 2002 it amounted to approximately 50 visits per day. Visitors show a main interest in the following documents (in order of number of downloads): - The fuel, ash and condensate composition databases - The Task 32 brochure - The Fuelsim Average model - The report on barriers for cocombustion - Reports from previous task meetings In order to maintain a growing number of visitors, it is essential that the internet site remains up to date and new information is added continuously. Further, all task members are asked to check if their personal information displayed is correct and complete. The internet database currently contains approx. 1000 biomass samples, 560 ash samples and 30 condensate samples. Larry Baxter analysed the data and came to the conclusion that a few records seem to contain incomplete or partly erroneous data. Good quality, additional composition data can be sent to Ingwald Obernberger.

Thursday June 20: Task meeting Part 2 Country presentations Austria Ingwald Obernberger presented three recently implemented demostration projects in Austria: - EU demonstration project wit ORC This refers to a biomass fired CHP plant of 1000 kWe in Lienz, Austria, based on an ORCprocess. Net electrical efficiency is approx. 14-15%, thermal 75%. The process is controlled using fuzzy logic equipment. Flue gas cleaning consists of a multicyclone, economiser, wet electrostatic filter combined with a flue gas condensation unit. The investment costs of the CHP plant alone were 7,7 M€. Details are provided in Annex 10. - Stirling engine demonstration projects (Joanneum Research Graz and TU Copenhagen) Joanneum Research (JR) is performing research and development of small scale biomass fried stirling engines. Basic versions of 3 and 30 kWe have been produced and are currently being tested for small scale CHP operation. Details are provided in Annex 10. - New gas turbine technology with innovative recuperative heat exchanger (Pebble Heater) The „Pebble Heater“ is a regenerative heat exchanger which was originally developed for applications in the steel industry. A new application for the Pebble Heater is the biomass power plant. A license agreement between ATZ EVUS and SIEMENS has been closed in

11

2000, which includes the joint development and the marketing of the SiPeb technology. BIOS, Graz, is a research partner investigating the ash related problems. In 2001 a pilot plant has been built in Sulzbach-Rosenberg; the tests are running until August 2002; next step is a full scale reference plant. Biomass combustion is used to heat a batch of material with large heat capacity (e.g. alumina oxides), after which the hot pebbles are used to produce hot air and drive a hot air turbine. The system would be suitable to produce nominal electrical power of 2-5 MW with electrical efficiencies exceeding 30%. Details are provided in Annex 10. Netherlands Ad van Dongen (Reliant Energy Power Generation Benelux, Netherlands) presented some of the major issues with regard to the plans for cofiring biomass in coal power plants in the Netherlands. Details of the situation are provided in the overheads, enclosed in Annex 11. Of the central installed power generation capacity of 14.000 MWe, 4.000 MWe is coal-fired and 14.000 gas fired. Of this capacity, Reliant has approximately 4,650 MWe installed generation capacity. The Netherlands’ Kyoto targets are 6% reduction in 2010 as compared to 1990. Regarding renewable energy, there is a policy target of 10% in 2020. On April 24, 2000, the Netherlands government has signed an agreement with the electricity producers on the reduction of CO2 emission. In this coal agreement, it is stated that the coal power plants should reach the same CO2 emission per kWhe generated as the gas fired plants. This implies a reduction of 5.8 Mtons of CO2 for the coal power sector. Of this target, 3,2 Mtons should be reached by replacing coal by biomass, this is equivalent to an average 12% on energy basis. Significant modifications will have to be carried out at the power plants to allow this high percentage of cofiring. In the agreement however, the government promises to provide financial support and instruments up to a level that an internal rate of return of 12% is reached on investments needed. The domestic availability of biomass in the Netherlands is by far not enough to fulfil the obligations of the coal agreement. Approximately 2,5 Mtons of biomass is needed for the coal power plants, in addition to the existing claim of about 1,6 Mtons from existing and other new initiatives already in the pipeline. It is therefore expected that the Netherlands will import biomass on a large scale. USA Larry Baxter presented some important recent developments with regard to biomass combustion in the USA (see Annex 12). The government support structure for biomass projects in general has been transformed significantly. As observed in other countries, government support for pure research on cofiring and combustion is reducing, as it is considered commercially viable. However, an increased attention on gasification and pyrolysis can be observed. The biofuels program is essentially eliminated. Further, Larry Baxter showed some results of recent work on modelling combustion and corrosion mechanisms in grates and PC boilers. New models developed are able to predict particle trajectories inside the boiler and vapour deposition and corrosion, based on local gas composition. An interesting observation is that striated flows may occur in some boilers,

12

resulting in locally reducing conditions while the average conditions may be oxidising. Under such reducing circumstances, the prevention mechanism of chloride corrosion on superheaters through sulphur from coal does not work. Other research has focussed on the impact of cofiring different types of biomass on the mechanical properties of cement. Preliminary results indicate that one should add more aerating agent to achieve good properties. The set time is also longer. However, the fluxural and compressive strength are not very much affected. Finally, BYU has nearly completed a review of over 40 US-based cofiring demonstrations, which will be useful for the new Task activity that will overview past cofiring demonstration trials world-wide (see p. 9). Denmark November 2001, the new Danish government has dramatically cut the budget for renewable energy from over 300 MDkr to approx. 40 MDkr. Government support on bioenergy is also suffering from this. The Danish Kyoto targets for CO2 reduction are –20% in 2010, currently approx 12-14% is achieved. The new government has allowed flexible instruments (JI, CDM) to be used for the remaining part. Part of the reduction is currently achieved through the biomass agreement between the government and the electricity producers of 1992, in which the electricity sector promised to use 1,4 Mtons of biomass. Currently, some 900 ktons of straw are used in addition to 500 ktons of woodfuels. In 2000 a large joint project was initiated by a consortium consisting of consultants (Dk-teknik also participated), euiqpment suppliers (Babcock and FLS), power producers and the University of Aalborg. Important results of this so-called Joint Project are CFD models and dynamic models that can be used for process optimisation and design of new grate boilers. A second phase is currently initiated in which these models will be validated. Finally, it is mentioned that the Danish Energy Agency’s Follow-up Programme for Decentralised CHP on Solid Biofuels has produced interesting reports on the performance of Biomass CHP plants. These reports can be downloaded from the below links: http://www.ens.dk/graphics/Publikationer/Forsyning_UK/CHP_Status_Report_1999.pdf http://www.ens.dk/graphics/Publikationer/Forsyning_UK/CHP_plants_Status_2000.pdf Australia It was mentioned in an earlier task meeting that Australia accepted the mandate on 2% additional Renewable Energy in 2010, which should result in 9500 GWh of additional renewable energy. An important contribution to this target is expected from bagasse, burned in upgraded sugar mills. The price difference between producing green electricity as compared to electricity from coal is currently approximately 30 Aus$/MWhe. If the power producers do not meet the above target, they are forced to pay a penalty charge of 40 Aus$/MWhe. The current price of green certificates is 35 Aus$/MWhe.

13

Norway A country report from Norway is attached in Annex 13.

Switzerland Overhead sheets from the Swiss country report from are enclosed in Annex 14. Recently, a number of R&D projects have been carried out in Switzerland on optimisation of combustion processes (process control and NOx reduction, see Annex 17 for a paper on fuel staging), aerosol formation, optimisation of pellet production and gasification. Recently a Swiss quality standard has been introduced for wood pellets that guarantees limited abrasion, low contents of heavy metals and forbids the use of additives during production. The Swiss norm is therefore more stringent than the Austrian ÖNORM M1735 and the German DIN 51731. With regard to stimulating market implementation, significant progress has been made in the field of Quality Assurance and System Optimisation of automatic biomass furnaces (see Annex 18), standardisation as well as education/training of engineers on application of biomass furnaces. Results of recent Swiss R&D projects can be downloaded from the publications site of ENET (see www.energieforschung.ch , click on ENET → publications → wood). Further, Thomas Nussbaumer refers to two papers on aerosols from biomass combustion, which were presented at the 12th European Conferences & Technology Exhibition on Biomass for Energy, Industry and Climate Protection in Amsterdam. Annex 15: Aerosols from Biomass Combustion –Overview on Activities in IEA Bioenergy Task 32, T. Nussbaumer and S. van Loo Annex 16: Nanoparticle Emissions of Novel Wood Combustion Processes, C. Gaegauf, U. Wieser, R. Hermansson, and V-P. Heiskanen Another paper enclosed in the annexes are: Annex 17: Fuel Staging for NOx Reduction in Biomass Combustion: Experiments and Modeling. Roger Salzmann and Thomas Nussbaumer, Energy & Fuels 2001, 15, 575-582 Annex 18: Quality Assurance for Planning and Construction of Biomass District Heating Plants, R. Bühler, H.R. Gabathuler, J. Good, A. Jenni

Canada In Canada, bioenergy contributes about 6% or 6 PJ to the primary energy mix (mainly in pulp and paper and lumber industries). There is an increased interest in landfill gas and pyrolysis. Recently, the Canadian government policy for funding renewable energy has dropped from approx. 40 to 15 million Canadian $. In addition, bioenergy has to compete with other RE options on a basis on cost effectiveness for CO2 abatement. Small dust particles have recently been declared as toxic material and has therefore become a federal issue. In particular the residential woodstoves cause relatively high emissions. Research on bioenergy is therefore focussing on emission reduction, with hardly any work on

14

CHP or cofiring (electricity production is mainly done using hydro power, with limited use of coal and nuclear power).

UK Under the Renewables Obligation, the UK regional electricity companies are forced to generate 10% renewable energy by 2010, with a non-compliance penalty of 30 £/MWh e. As a result, the pull price has dropped from 20-25 £/MWh e to 15 £/MWh e. As in other European countries, a trade in Renewable Energy Certificates has started. The British government is considering to set a policy target of 20% renewable energy in 2020, which can only be achieved if offshore wind and (especially in Wales/England) biomass cofiring are used on a large scale.

European Commission The budget for renewable energy under FP5 was approx. 150 M€/y with 35 M€/y on biomass. Under FP6 as a whole (duration of 4 years), this will amount to approx. 700 M€ with 100..150 M€ for biomass. There will be a preference for large projects covering the full conversion chain, that can be implemented on a short or medium term. With regard to the type of topics to be covered, the Commission has received approx. 15.000 Expressions of Interest from the market on various topics. It will take significant effort to prioritise different topics based on this response.

Sweden Various developments related to bioenergy take place in Sweden. The use of wood pellets has increased substantially. The pellet production capacity is about 1 million tons/y, the actual production has reached approx. 800 ktons/y. With about 30.000 pellet burners and stoves in households, the demand has reached a level where scarcity and price increases can now be sensed. However, still most of the pellets are used in smaller district heating plants as such or crushed in pulverised burners. A ban on landfilling combustible waste is expected to result in a doubling of incineration capacity, this may result in 4 TWh additional generation. Until 2005, a framework programme on waste wood combustion is executed. This topic comprises many issues including fuel quality, fouling and corrosion, emissions, etc. For an overview of ongoing activities see Annex 1. Part of the results will be made available through Task 32 (a.o. a workshop in Japan, see page 9).

Next meetings and workshops (Sjaak van Loo) At the first meeting of Task 32 it was agreed to have our next meeting in New Zealand. However, a significant cut in the financial budget of John Gifford has forced him to cancel his involvement in this action. Instead, after a lengthy discussion task members agreed to try to organise our next meeting during the 28th International Technical Conference on Coal Utilization & Fuel Systems in Clearwater, USA, March 10-13, 2003. Efforts will be made to (co)organise a cofiring seminar at this meeting.

15

The final meeting of Task 32 will be held autumn 2003 in Japan. At this meeting, Task 32 will organise a seminar on waste wood combustion (see also page 9).

Cofiring seminar (part of main conference) With inputs from Task 33 (biomass gasification) and the European Bioenergy Networks (EUBIONET), Task 32 organised conference seminar WS5 cofiring biomass in coal power plants. A summary of the contents of the presentations is provided below, the full report with overhead sheets can be downloaded from the Task 32 internet site. Bill Livingston (Mitsui Babcock) has presented an overview of cofiring issues. Cofiring biomass with coal is becoming increasingly popular around the globe for various reasons. It is often found to be a relatively low-cost measure for large-scale renewable energy generation. Depending on the specifications of biofuels to be cofired, various configurations exist, varying from directly mixing biofuel with coal and joint firing, pre-gasification and parallel firing. However, there are several barriers that hinder actual implementation, such as uncertainty about the legal and political environment, liberalization of the energy sector, as well as uncertainties about long term fuel supplies at low costs. Another issue is the utilization of flyashes, which is often not allowed if the ash is partly from biomass origin. One of the companies that has practical experience with cofiring biomass fuels is Fortum. Kati Savolainen (Fortum) presented the results of test trials in the Naantali Power plant. This showed that up to 2,5% of pine sawdust could be cofired with coal, without investment. For higher percentages, problems occurred with unburned carbon in the ashes, mill drying capacity and mill clogging. In the Suomenoja power plant (Finland), a demonstration project has been initiated aiming at replacement of coal by various types of biomass up to 20%. For this purpose, other biomass pretreatment equipment is necessary. In the USA, a lot of fundamental research work has recently been performed on the causes and effects on emission reduction when cofiring biomass with coal. Larry Felix (Southern Research Institute) highlighted some of the major results. Regarding NOx reduction, recent R&D has indicated that there one should generally not expect any NOx reduction beyond that of displaced fuel nitrogen (this was mentioned in the US National Energy Policy as important argument for cofiring). The effects of boiler geometry, fuel specifications etc. on NOx emission reduction, flame stability, slagging and fouling and other effects are further examined in various R&D projects. In 2000, US DOE has funded 11 new R&D projects, which all aim at better understanding such relations. One major barrier for many cofiring initiatives worldwide is the marketability of the power plant residues, if biomass is used as a secondary fuel next to coal. In the case of the Netherlands, the EN450 norm for utilization of fly ash in cement is currently being revised, based on maximum percentages of alternative fuels and the technical and environmental performance of the resulting fly-ash. In the presentation and enclosed paper by Frans Lamers, the impacts on quality of fly-ash are described in more detail. Larry Baxter (Brigham Young University) also showed the results of recent research projects in the USA on the characteristics of concrete produced with biomass derived fly-ash (concrete strength, set time, etc.). It generally shows that for biomass fly ash, more aerating agent is required and the set time increases. However, the compressive and flexural strength seem to

16

be hardly affected. Other major technical issues being examined are fuel handling and preparation, NOx formation, deposition, ash deposition, corrosion, SCR deactivation, carbon conversion and striated flows. Advanced models have already been developed that can be used to predict these effects for various fuels, operating conditions and boiler designs, however further research on such relations are necessary. Martti Aho (VTT) showed interested results from coal/biomass cofiring tests in practical-size fluidized bed boilers, with focus on emissions, superheat corrosion, ash composition and fouling. For different flue gas components, results from measurements and calculated catchment efficiencies have been analyzed. With regard to superheater corrosion from alkali chlorides, Martti Aho showed that sulphur dioxide and aluminia silicates derived from coal constituents can have a protective effect. Through a reaction with alkali chlorides under oxidizing conditions, alkali silicates and sulphates are formed, which prevent chlorides from condensing on the superheater tubes or leaving the boiler as fine fly ash. This mechanism was also mentioned in the presentation of Larry Baxter. Esa Kurkela (VTT) shared experiences with the Lahti CFB gasifier demonstration plant and the Corenso gasifier for plastic wastes. In the Lahti plant, a 60 MW biomass/waste fired CFB gasifier supplies gas to a 360 MW coal/natural gas fired steam generation boiler. The gasifier fuel consists of a mixture of plastics, REF, and (glue containing) wood. It has been commercially operating since 1998 with an availability of 86.6%. The effect of the gasifier on the emissions of the main boiler was that most of the emission components (such as NOx, SOx and particulates) decreased, except for HCl and some heavy metals. Investment costs of this type of gasifier are approximately 600 €/kWe. Another gasifier successfully operating since 2001 is the 40 MW Corenso installation. This gasifier is fed with plastic waste, consisting of a PE/Al mixture. The aluminum can be recovered at the gasification stage after, while the remaining product gas is burned together with oil to generate steam. In addition to the experiences shared by Esa Kurkela, Mark Paisley (FERCO) explained some more details on biomass gasification in combination with firing the producer gas in a coal furnace. One major advantage of pre-gasification is the fact that the biomass ash does not enter the coal furnace and mix up with the coal fly ash, causing marketing problems. Also, the volume of producer gas is much smaller than that of flue gas, therefore removal of unwanted components is simpler. Producer gas can often be fired in existing natural gas burners without modification. If producer gas can be used as a reburn fuel instead of natural gas, NOx emissions of an existing boiler could be reduced up to 60%. Experiences gained with the Vermont gasifier and other installations make that there is a growing confidence and familiarity with the concept of biomass gasification, not only in combination with utility owned coal fired boilers but also in other sectors, such as the pulp and paper industries.

17

Future actions • The task leader will find out whether we can host our next meeting at the 28th International Technical Conference on Coal Utilization & Fuel Systems in Clearwater, USA, March 1013, 2003. It may be an option to (co)organise a cofiring seminar at this conference. • The final meeting of Task 32 will be held in Japan, autumn 2003. A seminar on wastewood combustion will be organised at this meeting. • All task members will be provided with information brochures on the Handbook. It is encouraged that task members distribute this information in their respective countries. • A data format for initiatives on cofiring will be prepared, after which everyone will be asked to come up with information. • Task members are asked to indicate interest in participation in either of the proposals on cofiring, submitted by Larry Baxter. • Task members are invited to submit data on recently built biomass CHP plants to Austria for the preparation of a technological overview. • The description of individual task members on the internet site is incomplete. Please email a brief description + photograph to Jaap Koppejan. • Task members are invited to submit data on biomass fuel ash composition to Austria.

18

Annex 1.

Waste wood combustion (task proposal, Claes Tullin)

Background Significant quantities of waste wood are produced annually from various sources. Waste wood is a biomass fuel and therefore interesting to use in order to decrease the fossil CO2 emissions. Certain waste streams contain material with a very low content of contaminants, whereas other waste streams are heavily contaminated due to the use of wood preservatives, paints etc. (cf fig. 1). Consequently, there are possibilities to sort and classify waste wood in (at least) two streams where one stream containing most of the contaminants can be directed to incineration plants and the other stream containing the “clean” fraction of the waste wood can be used in conventional plants. In Sweden, the combustion of waste wood being a cheap fuel has increased rapidly in recent years. However, problems not least with increased rates of deposition and corrosion have been noticed. This is believed to be an effect of higher contents of metals such as zinc and lead. The waste wood is burned in fludised beds or grate combustors usually burning only waste wood or a mixture of waste wood and forest residues or in some cases also sorted waste fractions (RDF). In Sweden, the practical experience in using waste wood is considerable and several studies regarding waste wood is in progress (enclosure 1). Also in other IEA countries, the interest of using waste wood as a renewable energy source is increasing and many projects has been carried out over the years. Since both the quality of waste wood differs from market to market depending on different uses for instance of wood preservatives and since the combustion strategy also varies, it should be useful to exchange information.

Proposal The objective is to exchange and report information on the status in waste wood combustion among the IEA countries. Issues such as fuel quality classification, upgrading processes, sources of contaminants, handling and combustion experiences, formation of deposits, corrosion and emissions should be covered. This can be achieved either by • compiling a report or • by arranging a seminar with invited speakers.

Organisation Project leader: Claes Tullin Participating Countries Sweden, others inteested

Time plan and costs To be determined

Production of timber, boards etc.

Treatments: - Preservatives - Paints etc.

Use

Upgrading & Material Recycling

Demolition, Waste

Contaminated Waste Wood

“Clean” Waste Wood

Metals, glass, plastics, …

CCA, painted, …

Incineration

Extraneous Waste

Co-combustion with biomass, coal etc.

Waste Wood- ongoing activities in Sweden The use of wood in the society is extensive and significant amounts of waste wood are generated anually for instance from demolition of buildings and from industrial products. In recent years, a large interest for the use of waste wood in heat and power plants can be noted and in Sweden the annual use of waste wood for heat and power production corresponds to more than 1.5 TWh (Andersson and Tullin, 1999). The potential annual use has been estimated to be 4 TWh in 2005 (SoU, 1995) and at present a number of boilers for waste wood combustion are planned and under construction. However, the combustion of waste wood is not straight forward as it may contain contaminants due to wood preservatives, paints etc. as well as extraneous materials such as plastics, glass, metals due to inadequate sorting. Also problems with high dust concentrations during storing and handling have been reported (Andersson and Tullin, 1999). Analyses of the ash from the combustion of sorted waste wood compared to forest residues (virgin wood material) reveal that the waste wood in general contains higher concentrations of arsenic, lead, zinc, copper and chromium (Andersson and Tullin, 1999). The presence of arsenic together with higher values of chromium and copper reveals the presence of CCA1-treated wood. In Sweden, the use of CCA as a wood preservative has been extensive and about 5% of the waste wood streams has been estimated to consist of treated wood (Tullin and Jermer, 1998) and special efforts have been maid to identify and remove arsenic containing wood. Due to the complexity of the problems a research programme administrated by the Swedish Thermal Engineering Research Institute has been initiated. The objectives are (1) to in detail define the problems encountered when using waste wood, (2) explain the underlying mechanisms and (3) to provide solutions for these problems. In the first phase, reported in 2001 (Jermer et al., 2001; Andersson and Högberg, 2001; Sjöblom, 2001; Harnevie and Olvstam, 2001), the focus was on the two first questions. It was stated that the problem when using chips from waste wood can be divided into different categories; operational problems, environmental problems as well as restrictions related to new EC-regulations. The environmental problems when burning wood waste are related to the chemical composition of the fuel. In some fuel deliveries, sorted waste wood has a content of heavy metals in the same range as for ordinary biofuels. In other cases, the degree of contamination is unacceptable. Fouling of heating surfaces is one of the most significant combustion problems for chips from waste wood. The rate of fouling and deposition on the heating surfaces will increase three to five times compared to ordinary biomass combustion in the same boiler and under the same conditions. Fouling has been shown to occur regardless of the furnace used, whereas the dimensions and design of the heating surfaces have a more significant influence. The deposits formed are more corrosive over a broader temperature range compared to deposits formed during combustion of ordinary wood chips. This expands the corrosion problems to surfaces constructed of lower alloyed steels such as furnace walls and primary superheaters. In addition to the typical components of wood ash (such as calcium, potassium and sulphur), zinc, lead and sometimes titanium are enriched in the deposits. Most fuel fractions of sorted waste wood will be affected by the new EC-restrictions for combustion of waste. This is due to the fact that analysis of these fuels show higher content of halogens and most heavy metals than for example analysis of clean wood chips. The EC-restriction will mean more stringent rules for emissions compared to the present levels for these plants.

1

CCA- Copper, Chromium, Arsenic

Annex 2.

Inventory of cofiring experiences word-wide (task proposal, Jaap Koppejan / Sjaak van Loo)

Coordinated by: Participating countries: Duration: Budget:

Jaap Koppejan and Sjaak van Loo, TNO All with cofiring experience June 2002 - June 2003 35.000 Euro

Cofiring of biomass in large thermal (power) plants is gaining popularity world-wide as an alternative to dedicated biomass fired power plants based on relatively small-size steam cycles. Reasons are the lower capital and operating costs, higher electrical efficiencies and increased fuel flexibility and the avoidance of additional generation capacity. Besides the CO2 benefits that take place when fossil fuels are substituted by biomass, both NOx and SO2 emissions can often be reduced. The technique of co-firing biomass as a supplementary energy source in existing high efficiency boilers has been practiced, tested or evaluated for a variety of biomass types and cofiring shares in combination with different combustion technologies and processes, including grate firing, fluidised bed combustion and pulverised combustion. Cofiring usually refers to bringing biomass into a pulverised coal furnace. In Scandinavian countries however, the interest is growing for cofiring different forms of biomass with waste. In the pulverised coal fired installations such as operating in central Europe, the percentage of biomass that is cofired is relatively small as compared to the fluid bed installations operating in Scandinavia. One of the aims of Task 32 is to accelerate market introduction of biomass cofiring systems by exchanging experiences in the area of biomass cofiring. Supported by large power producers, the Executive Committee of IEA Bioenergy has recently mentioned that it would be highly desirably if Task 32 would prepare an overview of experiences with cofiring world-wide, which also provides an overview of the key technical issues and ways to tackle these. As mentioned before in earlier publications of Task 32, the main technical problems that may arise in cofiring systems are related to the fuel feeding system, the combustion system, flue gas cleaning system as well as the usability of the by-products. It is therefore suggested to execute a task-funded project with the following components: − Overview of installations in the EU, the US and other IEA member states that cofire different types of biomass, including the type of fuel, power plant, capacity, plant configuration, etc. − Overview of technical problems faced in cofiring systems and ways to overcome these. − Discussion and evaluation of the results achieved − Compilation of the results in a report (title equal with the project title). In the execution of this project, use will be made of recently prepared national and European overviews as well as other information available to individual task members. The activity will be co-ordinated by the Sjaak van Loo (Task leader) and Jaap Koppejan with support of interested task members. Financial support will be made available to Task members willing to contribute to this project with relevant information on experiences, etc. (the amount depends on the type of contribution). Coordination costs are covered by the task leader.

Annex 3.

Comparison, validation and assessment of methods for the determination of the annual efficiency of biomass-fired district heating plants (Task proposal, Thomas Nussbaumer)

IEA Bioenergy Task 32

Project Proposal Proposal 1) Comparison, validation and assessment of methods for the determination of the annual efficiency of biomass-fired district heating plants Proposal 2) as an alternative to 1: Assessment of methods for boiler efficiency and measures for efficiency improvement Thomas Nussbaumer Verenum

Background: Part load operation

Leistung [%]

100

Load

80

momentan erzeugte Combustion Feuerungsleistung heat output (Abgas)

Boiler abgegebene momentan Wärmeleistung (Wasser) heat output

Sollwert Heat demand Wärmeleistung

60

40

20

0

Minimum cont. heat output kontinuierlicher Betrieb

intermittierende Glutbettunterhalt Teillast diskontinuierlicher Betrieb = Schwachlastbetrieb

intermitt. Teillast

Zeit

kontinuierlicher Betrieb

Verenum

Automatic ignition and load control +

Leistungsregelung

TK

Soll

-

λ Soll

-

TK

+

λ

Verbrennungsregelung

4

M

Verenum

Accounting of delivery of biomass To enable economic operation of district heating plants, the accounting for delivered fuel should be done in a re liable and easy way. There are several possibilities to charge the delivery of biomass to combustion plant which can in principal be d istinguished in three categories (if there are further relevant methods, please let me know): - M easurement of mass and humidity. Example: 30 MWe power plant for wood in Cujik, NL that we visited recently during an IEA meeting, straw fired power plants in Denmark. Disadvantages: An accurate measurement of the humidity is difficult as it can vary within one delivery. Further, also the content of ash and non-combustible parts should be measured. This method is well suited for large plants. For small plants, the infrastructure for a balance for trucks is too expensive and hence the opportunity of weighing does not exist. - M easurement of volume and humidity. Example: Delivery in district heating plants in Switzerland from 0.5 MW to 5 MW. Disadvantages: Humidity and ash (see 1). Further, the bulk density of dry biomass can vary in wide ranges and hence should be measured or well known for the specific fuel, which is usually not the case. - M easurement of produced heat and calculation of annual efficiency of the plant. Example of application: District heating plants in Switzerland from 0.5 MW to 5 MW (as an option to method 2). Advantage: Simple, fast, and cheap.Disadvantage: Uncertainty in the determination of the annual efficiency, limitation to one single fuel supplier or a consortium of suppliers.

1

2

3

Verenum

Aim of the activity A cheap accounting of delivery of biomass fuels with different water content, density, and ash content is proposed using a m easurement of the heat production and an estimation of the annual efficiency. Since the annual efficiency is crucial for this method, a comparison, validation and assessment of existing methods for the determination of t he annual efficiency of biomass-fired district heating plants is carried out. The proposed formula and assumptions are evaluated. If n ecessary, a new formula will be proposed. Work plan and time schedule No

Activity

1

4

Collecting and comparative description of methods applied for determination of annual efficiency Collecting and comparative evaluation of measurements of annual efficiencies mainly in heating plants and if available power plants If measurements of the necessary data are available from different plants and countries, the measurements can be used for an evaluation of the accuracy of the (one or more if available) empiric formula Presentation and discussion of the findings in an IEA meeting

5

Report with results, findings, and recommendations

2 3

Months after start 2 6 8

8...10* 12

*depending on schedule of IEA meetings

Verenum

Interested countries Switzerland: Verenum, Swiss Federal Office of Energy, QA (R. Bühler) Denmark: dk-Teknik: Expression of interest by H.H. Jakobsen (correspondence before meeting) Belgium: CRA Gembloux: Expression of interest by J. Delcarte (correspondence after meeting) Further countries: If interested, please contact T. Nussbaumer and TNO Verenum

Option To enable a broader application of the results and as an option to the above described target „annual efficiency for accounting of biomass“, the project can also be formulated with the following aims and topics: • Comparison of methods for the determination of boiler efficiency, • Influence of part load operation, automatic ignition, and heat management on average boiler efficieny, and • Assessment for measures for efficiency improvement. Verenum

Annex 4.

Stoichiometry Effects on Corrosion during Cofiring (Task proposal, Larry Baxter)

Coordinated by: Larry Baxter, BYU Participating countries: All with cofiring experience Duration: 12 months Budget: 20.000-22.500 Euro _______________________________________________________________________

Objective The objective of this project is to measure the effects of overall stoichiometry on tube corrosion potential during cofiring of biomass and coal.

Background Under oxidizing biomass-coal cofiring conditions, SO2 contributed largely by coal reacts with alkali chlorides contributed largely by biomass to form alkali sulfates on tube surfaces, greatly reducing the corrosion rates of metals compared to those observed when alkali chlorides do not remain on the surface without reacting with sulfates. However, many modern boilers have low NOx burners or other features that create locally reducing conditions even if the overall stoichiometry is oxidizing. Theoretical calculations indicate that such locally reducing conditions, if present at metal surfaces, prevent chlorides from sulfating, thus greatly increasing the potential for corrosion reactions. These theoretical calculations are relatively recently completed and are based on equilibrium, ideal solution theory assumptions that are rational but not proven. Experimental verification of these predictions is required to develop more definitive evidence of corrosion mechanisms and rates.

Work statement Four blends will be formulated from two biomass fuels (one herbaceous and one woody fuel) mixed with two coals (subbituminous and bituminous) and will be used to generate deposits in a pilot-scale facility under conditions of burnout, tube temperature, gas temperature, and particle loading similar to those found in superheater regions of commercial, pc boilers (>98% burnout, 550 ºC tube temperature, 1200 ºC gas temperature, etc.). Local stoichiometry will be varied from reducing conditions to oxidizing conditions (total of 12 combustion tests). Deposits will be mounted in epoxy, cross sectioned, and examined under a microprobe to determine the extent to which chlorine layers form at the deposit surface interface. Local concentrations of CO2, CO, O2, SO2, and NOx will be monitored to verify conditions set by metered fuel and air feed rates.

Budget and Schedule This task requires $20 000US and will be completed in 12 months providing existing fuels are used (which we are happy to donate). If new fuels must be used, two additional months for fuel procurement and preparation and an additional $2 500 dollars will be required.

Annex 5.

Formation of Striated Flows During Biomass-coal Cofiring (Task proposal, Larry Baxter)

Coordinated by: Larry Baxter, BYU Participating countries: All with cofiring experience Duration: 10 months Budget: 10.000 Euro _______________________________________________________________________

Objective The objective of this project is to use state-of-the-art CFD models specifically adapted to biomass-coal cofiring conditions to predict the extent to which cofiring biomass with coal leads to the formation of striated flows in the convection passes or elsewhere in commercial boilers. Striated flows exist when local concentrations of biomass or coal and its combustion products are much higher or lower than the overall average concentration of the fuel and have the effect of producing conditions in a boiler that represent cofiring percentages in the combustor that differ markedly from the cofiring percentage inferred from total overall feed rates.

Background Ash deposition, corrosion, NOx formation and other fire-side issues often influence maximum cofiring percentages in commercial boilers. In other cases, fuel preparation, storage, and handling limit the amount of cofiring. Such maximum cofiring percentages are almost always based on total coal vs. biomass feed rates. Many issues of substantial importance to short- and long-term viability of cofiring depend strongly on the amounts of coal and biomass in the boiler. However, biomass cofired at more than trivial amounts is most commonly fired through dedicated burners, in which case the cofiring percentage in that burner is 100%. Many (probably most) boilers poorly mix the flows, to the extent that individual burner performance is often inferred from grid-based oxygen measurements near the precipitators of boilers. In such boilers, the effective percentage of biomass at one region in the convection pass is often much higher than is suggested by the overall feed rate. Such boilers have the potential to experience failures from tube bank plugging, tube corrosion, etc. that might seen avoidable based on overall cofiring percentages. This project attempts to quantify the risks of such behavior using the best available predictive technologies.

Work statement Simulations of two principal pc boiler designs, tangential firing and wall firing, will be completed using existing CFD capabilities for describing such flows at Brigham Young University. Each simulation will assume and overall biomass contribution of 10-20% based on energy input (gross calorific values). The specific cofiring percentage will be determined by the total number and the number of biomass-based burners. The boiler will be assumed to be in overall balance (stoichiometric ratio of each burner identical). Biomass will be assumed to be fed from dedicated burners located in the middle of the burner levels of the boiler, as is typical in commercial cofiring. The extents of mixing of biomass particles and their combustion products will be predicted as a function of position in the boiler, with local calculations of the mixing extent. If possible, simulations of actual cofiring demonstrations will be made, although this will require the cooperation and exchange of proprietary information by the

utilities and possibly the boiler manufacturers. In the absence of such cooperation, typical cofiring configurations will be used. This project involves no field work to collect data supporting the predictions, although such data would be a valuable (and expensive) addition to the work.

Budget and Schedule This task requires $10000US and will be completed in 10 months.

Annex 6.

Biomass Impacts on SCR Catalyst Performance (Task proposal, Larry Baxter)

Coordinated by: Larry Baxter, BYU Participating countries: All with cofiring experience Duration: 24 months Budget: 25.000 Euro _______________________________________________________________________

Objective The objective of this project is to develop data from a variety of combustion systems on the impact of biomass and biomass cofiring on SCR catalyst performance.

Background SCR control systems for NOx control are being installed in most OECD countries. This technology represents the only commercially demonstrated option for NOx reductions beyond 70%, which are required by many new or pending environmental standards. However, biomass fuels appear to affect SCR catalysts deleteriously. Specifically, catalyst activation rapidly decreases when biomass flue gases pass through catalysts. Anecdotal evidence indicates this effect is more severe when biomass is fired under high-intensity conditions.

Work statement Under this task, samples of initial and exposed catalyst materials from biomass or biomass cofired systems will be examined in BYU's catalysis characterization laboratory. In addition, a technical report on the commercial and laboratory experiences from the member countries will be compiled in a single review document. A critical evaluation of these experiences will be conducted in the context of the laboratory analyses. This work will be done in collaboration with an existing project on a similar subject but limited to US experiences and focused on slip stream measurements in which BYU is involved.

Budget and Schedule This task requires $25.000US and will be completed in 24 months.

Annex 7.

Combustion and co-firing network of excellence

European network on biomass combustion and cofiring

COMBINET

TNO Environment, Energy and Process Innovation

t

Sjaak van Loo, Task leader

Aim: • To establish • an EUforum for exchange of knowledge on biomass combustion and co-firing

• to provide: • manufacturing industry • end-users • governmental authorities • EU and national RTD Programme leaders • R&D organisations and universities

• with: • ideas, knowledge, tools, latest research results and experiences

t

COMBINET

IEA Bioenergy Task 32, 19 June 2002

2

t 1

Aim (2): • Through • Internet-based networking, newsletters, workshops & conferences, status and progress reports, etc.

• To: • promote and accelerate the development and demonstration of innovative, cost-effective technologies and related installations for environmentally sound energy generation from biomass by combustion and co-firing • stimulate and direct research • inform EU and Member State RTD Programme planners of research needs and priorities, and to improve the synergy and effectiveness of research projects in these EU and national RTD programmes.

t

COMBINET


3

Target subjects / problems Economy

• Cost-effective biomass/-waste supply and pre-treatment • Cost-effective (co-)combustion technologies competitive to coal-firing

Biomass/-waste

• Biomass/-waste characterisation • Biomass/-waste resource assessment, including security of supply • Preparation and handling

Ash related problems

• During combustion/co-firing: Agglomeration, Deposit formation, Corrosion, Aerosol formation • Ash handling and disposal: Characterisation, Legislation, treatment/reuse

Emissions

Reduction of: • Greenhouse gases • Aerosols

Modelling

• Compatiblity of models; guidelines for linking • Classification of models

Market/Implementation

• EU internal market for energy; technology take up and diffusion • Centralised, large scale plants versus decentralized installations • Opportunities for SME’s

CHP

• Opportunities with biomass/-waste • General experiences

t

COMBINET


4

t 2

COMBINET • First proposal submitted 14 dec 2001 – Priority area: Biomass (including waste) conversion systems (EESD-1999-5.2.1), Target Action B: Bio-electricity – 17 partners, 750 k€ – Scored 26 points, not accepted

• Expression of Interest for European Network of Excellence submitted June 7 – Aim: biomass (co)firing is priority on the European research Agenda – Possibly later NoE with at least 18 partners – Other countries are welcome to participate

t

COMBINET


5

Proposal 1 (rejected): 17 Partners 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17.

t

TNO Energy, Environment and Process innovation Technical university Graz (TU Graz) Mitsui Babcock Europe Agricultural Research Centre (CRA) Dk-TEKNIK Energy and Environment Technical Research Centre of Finland (VTT) University of Stuttgart Aston university; Bio-Energy Research Group Laboratory of Steam Boilers and Thermal Plants (NTUA) Neth. Agency for Energy and Environment (Novem) Norwegian University of Science and Technology (NTNU) Ansaldo Ricerche (ARI) Institute for Chemical Processing of Coal (IChPW) Instituto Superior Técnico (IST) Swedish National Testing and Research Institute (SP) Biomass Technology Group (BTG) Forschungszentrum Karlsruhe (FZK) COMBINET


6

t 3

At least 18 Partners in proposed NoE Type of organisation

Country

1 2 3 4 5 6 7

TNO Energy, Environment and Process innovation Technical University Graz (TU Graz) Mitsui Babcock Europe Agricultural Research Centre (CRA) Dk-TEKNIK Energy and Environment Technical Research Centre of Finland (VTT) Norwegian University of Science and Technology

Initiators and initial partners

R&D organisation University Industrial development R&D organization R&D organization R&D organization University

NL A UK B DK SF N

8 9 10 11

Swedish National Testing and Research Institute (SP) Verenum Research University of Stuttgart Laboratory of Steam Boilers and Thermal Plants

R&D organization R&D organization University University

S CH D G

12

Neth. Agency for Energy and Environment (Novem)

R&D Program Mgt.

NL

13 14 15 16 17 18

Ansaldo Ricerche (ARI) Institute for Chemical Processing of Coal (IChPW) Instituto Superior Técnico (IST) KEMA Centre for Renewable Energy Sources SINTEF

Industrial development R&D organization University R&D organization R&D organization R&D organization

I PL P NL G N

t

COMBINET


7

Project structure Secretariat (WP 4)

Network Co-ordination (WP 1)

Management Team Theme Working Group (WP 2) •Network co-ordinator (NC) •Theme Leader: Combustion •Theme Leader: Co-firing

European Commission

Other networks •ThermoNet (EU) - PyNe (pyrolisys) - GasNet (gasification) •IEA (combustion and co-firing)

(WP 2)

Tasks Working Group (WP 3)

Target groups (participants to ComBiNet) R&D •Universities •R&D organisations

t

Manufacturing industry •Engineering •Equipment •Control equipment

End-users Industry •Energy suppliers

COMBINET

Authorities & Decision makers •Governmental •City


8

t 4

Annex 8.

Decentralised CHP technologies based on Biomass Combustion (Task activity), Ingwald Obernberger

Decentralised CHP Technologies Based on Biomass Combustion - State of Development, Demonstration Activities, Economic Performance

T S U

AIN AB

ERGY EN

P

Ca Mg

EC

L

MA BIO S S

E

S

Ingwald Obernberger

K

ASH

ON OMY

Institute of Chemical Engineering Fundamentals and Plant Engineering, Graz University of Technology, Austria

S

Y

EN

BI

P

Ca Mg

EC

S

K

ASH

ON OMY

E

TAINAB L U SE R G OM AS

Research Group “Thermal Biomass Utilisation”

Institute of Chemical Engineering Fundamentals and Plant Engineering Graz University of Technology

Objectives (1)

The main objectives of the project are: !

Overview of technological developments and demonstration activities regarding small-scale biomass CHP systems in the EU, the US and other IEA member states.

!

Documentation as well as technological and economic evaluation of innovative small-scale biomass CHP technologies based on the information supplied from the project participants (data from national demonstration activities): " New steam turbine systems for small-scale applications (if available), " the new steam engine with oil-free operation, " the steam screw-type engine, " ORC systems, " Stirling engine systems, " new technological approaches regarding gas turbine processes.

S

BI

Y

EN

P

Ca Mg

EC

S

K

ASH

ON OMY

E




Objectives (2)

!

Collection of the economic and legal side constraints for decentralised biomass CHP plants in the countries of the project participants.

!

Discussion and evaluation of the results achieved (identification of weak points, of interesting fields of application for the different technologies addressed as well as of key parameters relevant for a successful realisation of such systems).

!

Compilation of the results in a report.

S

Y

EN

BI

P

Ca Mg

EC

S

K

ASH

ON OMY

E




Description of Demonstration Projects Already Considered

! EU demonstration project Lienz (1.000 kWel ORC) ! Stirling engine demonstration projects (Joanneum Research Graz, TU Copenhagen) ! New gas turbine technology with innovative recuperative heat exchanger (Pebble-Heater)

S

Y

EN

BI

P

Ca Mg

EC

S

K

ASH

ON OMY

E




Technological Evaluation of Decentralised Biomass CHP Plants

Relevant parameters to be evaluated ! ! ! ! ! ! ! ! ! ! !

Basic technology description Interface power process / combustion plant Operating mode / parameters Operating behaviour Control system Maintenance Ecological aspects State of development Weak-point analysis Cost analysis Benefit analysis

S

Y

EN

BI

P

Ca Mg

EC

S

K

ASH

ON OMY

E




Economic Evaluation of Decentralised Biomass CHP Plants I

! VDI guideline 2067 as basis for the cost calculations Distinction of four types of costs " capital costs (depreciation, interest costs) " consumption based costs (fuel, materials) " operation based costs (personnel, maintenance) " other costs (administration, insurance) ! Separate calculations of the heat production costs and the power production costs ! Data for the comparison with other CHP-technologies are available " biomass CHP applications in Austria, Denmark and Germany. Data from other partner countries are welcome and needed.

S

Y

EN

BI

P

Ca Mg

EC

S

K

ASH

ON OMY

E




Economic Evaluation of Decentralised Biomass CHP Plants

Distinction between: Electricity only production ! Total annual costs (capital, consumption, operation and other costs) must be considered for the calculation of the electricity production costs Combined heat and power production ! Split of heat and power production (calculation of additional annual costs in comparison to a heat-only plant with the same thermal power output) " capital costs (additional investments for power production) " consumption based costs (e.g. additional fuel costs) " operation based costs (e.g. additional personnel costs) " other costs (additional insurance, administration costs,…)

S

Y

EN

BI

P

Ca Mg

EC

S

K

ASH

ON OMY

E




Example: Economics – ORC Process / Technical Data

Technical data Net electricity power

P el

[kW el ]

500

Electric efficiency (CHP)

ν el

[%]

14

ν total

[%]

80

ν th

[%]

85

σ

-

Annual net electricity production

Q el

[kWh/a]

2,500,000

Annual heat production

Q th

[kWh/a]

11,785,714

Overall annual fuel demand (CHP)

Q fuel

[kWh/a]

17,857,143

Additional fuel demand for electricity production (in comparison to a heat-only unit)

Q CHP

[kWh/a]

3,991,597

Total efficiency (CHP) Thermal efficiency (heat-only plant) Electrical flow index

0.21

S

Y

EN

BI

P

Ca Mg

EC

S

K

ASH

ON OMY

E



Example: Economics - ORC Process Additional Investment Costs


Additional investment costs in comparison to a heat-only plant with the same thermal power output Thermal oil boiler, thermal oil cycle, economiser

[€]

145,400

Hydraulic installations

[€]

40,700

ORC plant

[€]

814,200

Generator

[€]

inclusive

Process control and electric cabling

[€]

36,350

Grid connection and transformer

[€]

109,000

Engineering

[€]

123,289

Other additional costs (building, transport, installation)

[€]

87,240

Total additional costs

I

[€]

1,356,179

I spez

[€/kW el ]

Specific investment costs without subsidies

2,712

S

Y

EN

BI

P

Ca Mg

EC

S

K

ASH

ON OMY

E



Example: Economics - ORC Process Full Costing Method (VDI 2067) I


Additional annual costs in comparison to a heat-only plant with the same thermal power output Interest rate

ir

[%/a]

6

Life time of CHP installation

n

[a]

15

Kk

[€/a]

Capital costs Specific capital costs Fuel costs Amount of other operating equipment

Consumption costs Specific consumption costs

[€/kWhel ]

0.056

[€/a]

43,508

[(% of I)/a]

Other operating costs Kv

139,636

0.3

[€/a]

4,069

[€/a]

47,577

[€/kWhel ]

0.019

S

Y

EN

BI

P

Ca Mg

EC

S

K

ASH

ON OMY

E



Example: Economics - ORC Process Full Costing Method (VDI 2067) II


Personnel hourly rate

[€/h]

Annual working hours

200

Personnel costs

[€/a]

Amount of maintainance costs

[(% of I)/a]

Maintainance costs Operating costs

Kb

Specific operating costs Amount of insurance and administration costs Insurance and administration costs Other costs

Ks

Specific other costs Total annual costs

Specific electricity production costs

22

K total

4,400 1.5

[€/a]

20,343

[€/a]

24,743

[€/kWhel ]

0.010

[(% of I)/a]

0.5

[€/a]

6,781

[€/a]

6,781

[€/kWhel ]

0.003

[€/a]

218,736

[€/kWhel]

0.087

BI

P Mg

EC

S

Ca K

ASH

ON OMY

Specific electricity production costs [€/kWhel ]

S

Y

EN

E




Example: Composition of Electricity Production Costs – ORC process

0,10

Full load operating hours = 5,000 h/a Fuel price = 1.1 €/MWh (NCV) No investment subsidies

0,09 0,08 0,07

specific other costs

0,06 0,05

specific operating costs

0,04 0,03

specific consumption costs

0,02 0,01

specific capital costs

0,00 ORC 500kWel

ORC 1.000kWel

Y

EN

BI

P



Ca Mg

K

ASH

ON OMY

Economic Comparison (1)

Economic performance of different CHP technologies other costs

160

production costs for electricity [€/MWh(el)]

EC

S

E

S


140

full load operating hours = 4,000 h/a fuel price = 10€/MWh (NCV) no investment subsidies

operation based costs

120 consumption based costs

100 80

capital costs 60 40

range for electricity production costs from large-scale nuclear power, coal or natural gas power plants

20 0

ST

SPE

SCE

ORC

STE

DGP

HGP


Ca K

ASH

ON OMY

100

Economic Comparison (2) other costs

full load operating hours = 3,000 h/a (*...4,000 h/a) fuel price = 10 €/MWh NCV investment subsidies = 0% operation based costs

80 consumption based costs

60

capital costs

40

20

ORC process*

Steam turbine*

Zeltweg (pilot plant)

St.Andrä (pilot plant)

0 Biomass gasification

electricity production costs [€/MWh(el)]

120

Separate biomass boiler

Mg

EC


Co-firing CFB

P

S

Co-firing in PCC plant

BI

Biomass grate

Y

EN

E

S



S

BI

Y

EN

P

Ca Mg

EC

S

E


K

ASH

ON OMY



Economic Comparison (3) ST

production costs for electricity [€/MWh(el)]

400 fuel price = 10€/MWh (NCV) no investment subsidies

350

SPE

300

SCE

250 ORC

200 STE

150 DGP

100

HGP

50 0 1,000

2,000

3,000

4,000

5,000

6,000

full load operating hours [h p.a.]

7,000

8,000


BI

P Mg

EC

S

Ca K

ASH

ON OMY




4000

Specific investment costs for electricity production [€/kW el ]

S

Y

EN

E


Stirling engine

3500

ORC process

3000

Steam turbine

2500 2000 1500 1000 500 0 0

1.000

2.000

3.000

4.000

nominal electric power [kW]

5.000

6.000

Ca Mg

EC

K

ASH

ON OMY




DGT high

P

S

STE SCE HGT ORC SPE ST

low

BI

potential for further development

S

Y

EN

E


low

high state of development

S

Y

EN

BI

P

Ca Mg

EC

S

K

ASH

ON OMY

E




Conclusions and Recommendations for Biomass CHP Plants (1)

Relevant technical side constraints for decentralised biomass CHP systems: ! Highly robust technology (high availability) ! High degree of process control and automatisation ! Low operation and maintenance costs ! Good partial load behaviour

S

Y

EN

BI

P

Ca Mg

EC

S

K

ASH

ON OMY

E




Conclusions and Recommendations for Biomass CHP Plants (2)

Relevant economic side constraints for decentralised biomass CHP systems: ! High number of full load operation hours (> 4,000 h/a) ! High overall efficiency (heat controlled operation) ! Low operation costs ! Utilisation of „economy of scale“ and „learning curve“ effects regarding a reduction of investment costs

Annex 9.

Internet site (Jaap Koppejan)

Internet site of Task 32

Www.ieabioenergy-task32.com

TNO Environment, Energy and Process Innovation

t

Jaap Koppejan

Internet site • • • •

t

Operational since July 2001 Growing number of visitors Growing amount of information Maintenance is necessary



2

t 1

Average visits per day 600 500 400

Hits Files

300

Pages

200

Visits

100 0 jul- aug- sep- okt- nov- dec- jan- feb- mrt- apr- mei- jun01 01 01 01 01 01 02 02 02 02 02 02

t



3

t



4

t 2

Visitors have main interest in: • Publications: • Reports on barriers for co-combustion • Workshop reports on co-combustion and aerosols • Information brochure

• The combustion emission model AVERAGE FUELSIM • The databases on biomass fuel and ash composition

t



5

t



6

t 3

To be added: • New data for biomass fuel and ash database, supplied by task members • Short description of task members + photograph

t



7

t 4

Annex 10. -

Country report – Austria, Ingwald Obernberger

EU demonstration project with ORC (1000 kWe, in Lienz, Austria) Stirling engine demonstration projects (Joanneum Research Graz, TU Copenhagen) New gas turbine technology with innovative recuperative heat exchanger (Pebble Heater)

T S U

AIN AB

ERGY EN

P

Ca Mg

EC

L

MA BIO S S

E

S

Biomass Combined Heat and Power Plant Based on ORC Technology „ EU Demonstration Project Lienz“

K

ASH

ON OMY

BIOS BIOENERGIESYSTEME GmbH Sandgasse 47, A-8010 Graz, Austria TEL.: +43 (316) 481300; FAX: +43 (316) 4813004 E-MAIL: [email protected] HOMEPAGE: http://www.bios-bioenergy.at

BIOENERGIESYSTEME GmbH Sandgasse 47, A-8010 Graz

EU Demonstration Project Lienz EU-Project Consortium

Project Title:

Fuzzy logic controlled CHP plant for biomass fuels based on a highly efficient ORC-process

Project Number:

NNE5-2000-00475

Project Co-ordinator:

Stadtwärme Lienz Vertriebs und Produktions GmbH, Austria

Project Partners:

TURBODEN SRL, Italy BIOS BIOENERGIESYSTEME GmbH, Austria Technische Universität Bergakademie Freiberg, Germany


EU Demonstration Project Lienz Main Data

Technical data ! Net electric power ORC:

1,000 kW

! Nominal power thermal oil boiler and ECO:

6,500 kW

! Nominal power hot water boiler:

7,000 kW

! Nominal power warm water economiser:

1,500 kW

! Start of CHP operation:

01/2002

! Site: Lienz, Tyrol / Austria

EU Demonstration Project Lienz Annual Energy Production


25.000 Solar thermal collector Peak load boiler

Power at CHP plant [kW]

20.000

Heat recovery Hot water boiler CHP-unit Electricity production

15.000

10.000

5.000

0 0

1.200

2.400

3.600

4.800

6.000

operating hours per year [h]

7.200

8.400


EU Demonstration Project Lienz Scetch CHP Plant


EU Demonstration Project Lienz Acts & Facts I

Biomass CHP Plant Lienz Roofed storage capacity

5,000 Srm

Open storage capacity

10,000 Srm

Solar thermal collector

630 m²

Nominal power thermal oil boiler

6,000 kW

Nominal power thermal oil ECO

500 kW

Nominal power hot water boiler

7,000 kW

Nominal power hot water ECO

1,500 kW

Nominal power oil boiler (peak load coverage) Maximum thermal power solar thermal collector Net electric power ORC Production of heat from biomass Production of heat from solar energy Production of electricity from biomass

11,000 kW 350 kW 1,000 kW 60,000 MWh/a 250 MWh/a 7,200 MWh/a


EU Demonstration Project Lienz Acts & Facts II

Primary Energy Bark, saw dust, wood chips from local saw mills

90,000 Srm/a

Rural wood chips

10,000 Srm/a

Investment Costs CHP plant District heating grid

7.7 Mio € 15.4 Mio €

Technological Innovations • First 1,000 kWel biomass combined heat and power plant based on the ORCprocess worldwide • First use of a heat recovering system in combination with a thermal oil boiler to increase the electric efficiency • Use of a Fuzzy Logic control for process optimisation • Efficient, multi-stage flue gas cleaning system consisting of multicyclone, economiser, wet electrostatic filter combined with a flue gas condensation unit

EU Demonstration Project Lienz Thermal Oil Boiler


flue gas recirculation

thermal oil boiler

flue gas fan

thermal oil outlet

thermal oil inlet multicyclone

secondary-air inlets thermal oil ECO

combustion air pre-heater

II

I primary combustion zone II secondary combustion zone

primary-air inlets

I

grate

bottom ash


dust precipitation Stage I

EU Demonstration Project Lienz Flue Gas Cleaning System

heat- recovery, flue gas condensation unit & wet ESP

external air

flue gas devapourisation air

cleaned flue gas flue gas

coarse fly-ash

multi-cyclone

sludge & condensate

economiser & wet electrostatic filter

condensate

flue gas devapourisation unit

stack


EU Demonstration Project Lienz

EU Demonstration Project Lienz ORC-Process I


turbine thermal oil cycle G

generator

thermal oil ECO thermal oil boiler

ORCprocess

biomass

regenerator evaporator Silicon oil pump

furnace

combustion air pre-heater

heat consumer

flue gas economiser combustion air

condenser


EU Demonstration Project Lienz ORC-Process II

9

11 10

1 Regenerator 2 Condenser 3 Turbine 4 Electric Generator

5 Circulation pump 6 Pre-heater 7 Evaporator 8 Hot water inlet

9 Hot water outlet 10 Thermal oil inlet 11 Thermal oil outlet


EU Demonstration Project Lienz ORC-Process III


Thermal power input (thermal oil) Heating medium

EU Demonstration Project Lienz ORC-Process IV 5,800 kW Thermal oil

Inlet temperature (at nominal load)

300°C

Outlet temperature (at nominal load)

250°C

Working medium

Silicon oil

Thermal output (condenser)

4,650 kW

Cooling medium

Water

Inlet temperature (at nominal load)

60°C

Outlet temperature (at nominal load)

80°C

Net electric power (at nominal load)

1,050 kW

Electric efficiency (at nominal load)

18.1%


EU Demonstration Project Lienz Energy Flow Sheet

Thermal oil boiler - ORC-process - heat recovery radiation and heat losses 8% thermal oil ECO

hot water ECO combustion air pre-heater

biomass input (NCV) = 100%

thermal output 75%

electricity output 14 - 15%

thermal oil boiler ORC-process

heat and electricity losses ORC 2- 3 %

Institute of Energy Research

Decentralised CHP Technologies Based on Biomass Combustion in the Micro-Scale Range – Stirling Engine Development

Joanneum Research-activities


Stirling Engine Activities at JR Kamin

Heizungsverteiler RL Saugzug Ventilator

Zyklon

VL

FEUERUNG/KESSEL 3MWth LADEPUMPE

Sekundärluft Biomasse

STIRLINGMOTOR Fernwärme netz

3x400V, 50 Hz, 30 kW GENERATOR Primärtluft

Kühlwasserpumpe Kühlwasser des Stirlingmotors

55...70° Netzpumpe

Entaschung

Application 1

3 kWel Biomass Test Stirling Engine Basic engine concept

Application 2

1 MWth Biomass District Heating Plant with CHPP (30 kWel Biomass Stirling Engine)

Grid Independent Electricity Production with Biomass Stirling Engine


Biomass CHP Plant with a Stirling Engine Kamin

Heizungsverteiler RL Saugzug Ventilator

Zyklon

VL

FEUERUNG/KESSEL 3MWth LADEPUMPE

Sekundärluft Biomasse

STIRLINGMOTOR Fernwärme netz

3x400V, 50 Hz, 30 kW GENERATOR Primärtluft

Kühlwasserpumpe Kühlwasser des Stirlingmotors

55...70° Netzpumpe

Entaschung


3 kW-Biomass Stirling Engine


30 (50, 100) kWel - Biomass Stirling Engine

Amsterdam, June 17-21, 2002

SiemensIndustrialServices

SiPeb®- New Innovative Approach to Biomass Power Plants

Your Success is Our Goal


SiPeb® Biomass Power Plants Research & Development ! The „Pebble Heater“ is a regenerative heat exchanger which has been developed for applications in the steel industry ! Various applications for the Pebble Heater have been developed by ATZ EVUS, a research institute. One of these applications is the Biomass Power Plant ! A license agreement between ATZ EVUS and SIEMENS has been closed in 2000. This includes the joint development and the marketing of the SiPeb technology. ! BIOS, Graz, is a research partner investigating the ash related problems. ! In 2001 a test plant has been built in Sulzbach-Rosenberg; the tests are running until August 2002; ! Next step is a full scale reference plant SiPeb Biomass Power Plants



SiPeb®- the Process

Exhaust Gas

Changeover

Biomass

G Air Steam / ORC turbine and/or heat consumer

Steam / ORC

SiPeb Biomass Power Plants



Basic Technical Data

! Nominal Electric Power 2 – 5 MW ! Electric Efficiency > 30% ! CHP applications on various temperature levels ! Maximum temperature in the Pebble Heater: 860°C ! Temperature at turbine inlet: 830°C




Pebble Heater Innovative Heat Exchanger

ATZ EVUS How does a Pebble - Heater work?

Exhaust

! A Pebble Heater is a regenerator which uses a pebble bed to store thermal energy

Cold Air

External Shell

! Small pebble diameters allow a great specific surface in relation to the volume and thus an intensive heat transfer. The temperature gradient is 1500-2000 K/m. The pebble bed is relatively thin in radial direction to minimise the pressure loss.

Cold Grate Hot Grate

Pebble Bed Valve Hot Gas from Combustion

Heating Phase SiPeb Biomass Power Plants

Hot Air to Turbine

Cooling Phase Your Success is Our Goal


Hot Air Turbine

How does the turbine work? ! In the compressor the inlet air is compressed to a level of 4 bar ! No combustion chamber, the thermal energy of the pebble bed heats the air up to 830°C ! After the expansion in the turbine the hot air can be used as a heat source for another process (i.e. steam production) and as pre-heated combustion air

Hot Air Turbine




Pilot Plant



Annex 11.

Country report – Netherlands, by Ad van Dongen (Reliant Energy, NL)

20-6-2002

ISSUES FOR LARGE SCALE CO-FIRING IN THE NETHERLANDS.

Ir. A.C. van Dongen. REPGB Reliant Energy Power Generation Benelux

[email protected] Tel : (31) 30-2472853 Fax : (31) 30-2472255 Date; 20-6-2002

Large scale co-firing in NL

1/13

20-6-2002

1. INTRODUCTION E-producers in the Netherlands.

2. POWER GENERATION IN THE NETHERLANDS 3. DUTCH POLICY FOR GREEN ENERGY. 4. COAL AGREEMENT 5. FUELS, FUEL ANALYSES AND CLASSIFICATION 6. INTEGRATION WITH A COAL FIRED POWER PLANT. 7. TECHNICAL CONTRAINTS FOR LARGE SCALE APPLICATION. 8. NON TECHNICAL CONTRAINTS. 9. CONCLUSION


2/13

20-6-2002

INTRODUCTION OF RELIANT ENERGY. ♦

♦

UNA WAS FORMED IN 1988. − −

Due to the law to separate the E-generation and E-distribution sector in the Netherlands. Combination U(Utrecht), N(North Holland) and A(Amsterdam) was formed

UNA WAS SOLD TO RELIANT ENERGY IN 1999. −

−

Due to the privatisation (liberalisation) of energy market. First company who was sold in the Netherlands.

♦ RELIANT ENERGY ORGANISATION/BUSINESS IN EUROPE 1 Power Generation. UNA renamed in REPGB (Reliant Energy Power Generation Benelux). 2

Power trading. – sell own and buy energy from the market. – optimise own plant dispatch.

3

Fuels trading. – buy fuels (gas, oil and coal) – sells fuels

♦ LOCATIONS of Reliant Energy. − −

−

Main office in Houston. European offices in Amsterdam, Frankfurt and London. Power plant locations in the Netherlands. * Utrecht (with district heating) * Amsterdam (Hemweg site) * Diemen (with district heating) * Purmerend (with district heating) * Velsen (with firing Blast Furnace gas, 36 and 480 MWe plants and one combined cycle plant of 145 MWe with heat delivery to Corus)


3/13

20-6-2002

POWER GENERATION IN THE NETHERLANDS. Installed capacity Central - Gas fired - Coal fired Decentral

14.000 MWe 10.000 MWe 4.000 Mwe 5.000 Mwe

Import capacity

3.350 MWe

Data of the year 2000 - Total E-production (Centr. and decentr.) 104.700 GWh - E-production companies delivered 88.700 GWh - Import 22.950 GWh - Export 4.030 GWh

Change as a consequence of the liberalisation. Original UNA

At this moment à Reliant Energy

Installed (in MWe) 3476

EPON

à Electrabel

4647

EZH

à E.ON

1770

EPZ(1)

à Essent à EPZ (2)

5345 (Note x)

Demkolec

à NUON (PWC)

253

(coal gasification)

- Z (1) to (2) Z changed from Zuid-Nederland to Zeeland (50% Essent/50% Delta) - Note x: This is total for Essent and EPZ including the many small combined cycle units in the distribution networks.

Remarks: - original E-producers owners were provinces and cities; now private companies. - SEP (Dutch electricity generating board) acted as co-ordinator for the E-producers.


4/13

20-6-2002

DUTCH POLICY FOR CLEAN ENERGY. ♦

Government is very ambitious for cleaner energy generation and application.

♦ Many fiscal instruments available for project stimulation; such as for - Investment -> Dutch CO2 reduction fund, EU subsidy etc. – Exploitation -> Ecotax, greencertificates, EIA, Vamil ♦ Much research and many feasibility studies have been executed. à now time to harvest what has been done. ♦ Target is 10% green energy in 2020; in 1999 only 1,2%. −

In 2020 expected 26% from biomass and 16% from waste; total 42%

− For split up of green sources see attached sheet. ♦

Government proposed to fire natural gas instead of coal. à Not accepted by the producers.

♦

Alternative à coal agreementà replace ca 15% coal by biomass.

♦

Signing of the agreement took a long time - problems financial support and emissions limits - E-producers wanted a level playing field in Europe.

♦

Target of coal agreement based on Kyoto protocol (10-12-1997).

− − − − −

6% reduction with respect to 1990 for 6 greenhouse gases in period 2008-2010. Reduction in Holland 25 Mt CO2 eq in 2010 For E-producers 5,8 Mt per year. For all coal fired plants 3,2 Mt per year. For consequences of the coal fired plant see attached sheet..

♦ Ecotax in 2002 for green E-power generation depending on consumption. Zone 0 – 10 MWh 10 – 50 MWh > 50 MWh

€cent/kWh 6,01 2,00 0,60


5/13

20-6-2002

Coal agreement (1). CO2 reduction • Coal substitution in power plants • Bench mark agreement (6-7-99)

3,2 Mton/y 2

(coal and gas plants >0,5PJ)

• Extra on voluntary basis • Extra in Coal gasifier Total

0,5 0,1 5,8 Mton/y

No national fuel import tax anymore to control the choice of the fuel A special notification (so called Circulaire), based on the LCP and WID directives, has been prepared to specify the emission limits. A distinction has been made between dirty and clean fuel. They different emission limits are indicated in the attachment.

The white (clean) and yellow (dirty) list is still in preparation and subject of final approval. à designation in clean and dirty fuel is in principle based on originà not on chemical composition because they contain in general less heavy metals and halogens.

From dirty to clean fuel is possible (clean should meet natural gas quality)

Alternatives for coal substitution by biomass •

Closing of the coal fired power plant

•

Change to natural gas firing

-à expemsive

• Alternative -à eg SRF fuels.


6/13

20-6-2002

Coal agreement aspects (2). Signed on april 24 by Ministers of EZ (econ.affairs), VROM (housing, physical planning and environment), the E-producers and EnergieNed Duration from 4 month after signing up to the end of 2012. Discussion about continuation shall be timely before 1-1-2011 At this moment, the attachments are worked out and a request letter is in preparation for approval by the EU Commission. The government will stimulate the routing of alternative fuels (SRF) to the coal fired plants to meet the agreement. à in the LAP (national waste routing plan) fuel >11,5 MJ/kg should be converted in a plant with a efficiency > 30%. à biogenic part in alternative fuels to be measured (see next page)

A QA document is in preparation to certify the biogenic part in the fuel. -> document still to be approved by the government.

Imported fuel shall be certified (must come from sustainable forestry) Target is level playing field-à what to do when requirements and circumstances change (negatively) in the future. Financial support and instruments are described for the case the income from co-firing projects is to low. The method to assess this is well described in a attached protocol


7/13

20-6-2002

Coal agreement aspects (3) Monitoring, reporting and evaluation. - progress each year by each partner in the yearly environment report - collectively what has been reached by EnergieNed - verification by the minister - evaluation of progress in 2003/5/8/12. The parties should have a positive intention for the unwanted suituation that basic aspects are changing. Aspects which may be discussion points; ♦ No normal exploitation results. ♦ No fuel ♦ No satisfactorily technology ♦ Problems with discharge/disposal of the residues due to a to high percentage co-firing ♦ Change of government policy Biogenic portion in the alternative (not 100% biomass) fuel

♦ Various determination methods have been investigated and assessed by doing an actual case ♦ A preferred method has been selected for using in the first years. ♦ Alternative determination methods are in discussion and also still welcome ♦ A certification system is being set up to convince the quality of determination ♦ CO2 credits count as 100% for the biogenic portion and partly for the non biogenic portion. ♦ The non biogenic portion is based on the efficiency difference between firing the waste in the dedicated waste incinerator and the power plant. ♦ Efficiency for the waste incineration is 22 %


8/13

20-6-2002

FUELS AND FUEL ANALYSES. ♦ Clean/fresh wood (pellets and chips) ♦ Thinnings, tree loppings ♦ Demolition wood ♦ Charcoal (import) ♦ Road side grass ♦ Sewage and paper sludges ♦ Chicken manure; poultry litter ♦ Olive industry residues ♦ Rice husk; citrus pellets ♦ Cacao shells ♦ Palm stone expellers ♦ Fullers earth (bleekaarde) ♦ SRF (solid recovered fuels;

former RDF)

♦ MBM (meat and bone meal; low and high risk) Which elements to analyse in the fuel will be standardised. -> see attached list in which the need for analysing is summarised Classification system for fuel trading is in preparation. -> see attached for the set up of the work to be done. -> the results will be evaluated in a sounding board of the standardisation commission


9/13

20-6-2002

INTEGRATION WITH COAL FIRED POWER PLANTS. ♦ Integration options and emission limits à see attached sheet . − − −

−

Biomass feed direct on coal conveyor before and after the coal mills. Pre-gasification followed by firing of the gas in the coal fired plant Parallel combustion with steam/water side integration Pyrolysis oil firing by a separate oil burner

♦ Hemweg 8 power plant data. − − − − − − − −

−

in operation since 1995 capacity 630 MWe efficiency 42,3 % (max 44%) Benson type boiler 36 burners (40 MWth) is 6 rows of 6 and located in opposite position low NOx burners and low NOx firing technology. Plant is provided with DeSOx installation DeNOx (SCR type) in discussion; depends on NOx trading. Operation experience is excellent

Large scale co-firing in NL 10/13

20-6-2002

TECHNICAL CONTSTRAINTS FOR LARGE SCALE APPLICATION. 1 When is a technology proven for a client. à what is needed to convince a client. à studies are often much to optimistic. à what is the worth of the knowledge besides the supplier and client? . 2 Which guarantees can/will be given and by whom?. 3 Reliable mass and energy balances incl. element distribution model − For coal plant in NL are semi-emperical correlations (within certain range) available based on many measurements in power plants. − Are good distribution models available far gasifiers/incinerators. 4 Operating window of the unit should not be small. à design should be flexible for different feedstock’s. à process should operate relative stable à fluctuations in feed should be possible à unit shall follow the coal fired plant load change of the connected

5 Storage, handling and transport of large quantities. −

Needs much design attention

6 Effect on the construction material behaviour of the power plant. - selection to minimise corrosion . 7 Behaviour of the fuel in and wear of the coal mill. 8 Slagging, agglomeration, fouling, corrosion and erosion in the boiler. – prelimenary data are available but more info is needed to determine the risks 9 DeNox catalyst deactivation (high priority for investigation) 10 Effect on and operation costs of the DeSOx installation. 11 Influence of the bottom and fly ash and gypsum. -> selling to the cement/concrete industry shall be maintained

12 Acceptance criteria for and QA for the fuel. – depends also on the coal quantity – a good set of criteria shall be set up (bases should be operating experience) Large scale co-firing in NL 11/13

20-6-2002

NON TECHNICAL CONSTRAINTS. 1 Fuel prices uncertain in a growing market (long term fuel supply contracts are not possible or can only be made with a higher than usual fuel price)

2 Open market/ liberalisation −

more competitors, cost cuttings and staff reduction

− à problem with introduction of new technology.

3 Construction costs (may be higher than based on first information). −

Who will subsidy and make a bid with guarantees.

4 E producers try to buy units as black boxes −

with extreme guarantees and

− only from companies which can take the risks in case of malfunction.

5 Long term government support should be sustainable. −

how sustainable are the temporary government financial instruments

− there is a great need for a European level playing field by implementing uniform policies

6 Marketability of the residues −

Selling of the ashes from the power plant to use for cement or as a concrete additive should not become problematic (or be contaminated by the burning of the oil and charcoal)

7 Emission limits. − local authorities may put stringent requirements − Dutch rules are going to be more stringent than elsewhere in Europe − à level playing field 8 Permitting issues − − −

Logistic problem (large transport volumes) many items cannot be described at this moment info from demo plant operation required.


20-6-2002

9 Public acceptance and perception 10 Financing and insurance 11 Risk assessment needed for investors

CONCLUSIONS. 1.

Tendency for using biomass is towards direct co-firing instead of pregasification and parallel combustion.

2.

Import of biomass is a must to meet the coal agreement.

3.

Much knowledge available but there is not a combined effort to realise a plant which can be used as a reference.

4.

Financial support should be concentrated by making choices (by whom??)

5.

Government should remain active now and in the future. − −

6.

To support the investment and share in the costs in case of malfunction. .. investment willingness is low because potential clients are now driven in a competitive market

Cost estimation at the start of a project shall not be to optimistic (who do you serve with a to optimistic price??)

Data from a B-IGCC (32 MWe) study phase 2150 EURO/kWe official bid 2800 including infra 3300 plant 12 MWe 4550 (original) actual 5000

7.

Coal agreement may speed up the use of biomass.


DoA 20-6-2002

DUTCH RENEWABLE ENERGY POLICY (Data in PJth as reduced fossil fuel use)

Source

Basis Status 1990 1999

Wind Solar (PV) Solar (thermal) Waste Biomass Heat pumps Hydro(intern) Hydro(Norway) Thermal storage Geothermal

5,3 0,1 0,4 12,1 16,0 0,2 0,7 0,5 0,0 35,3

Targets (PJth) 2000

2007

16 1 2 30 24 7 0 0 3 0 83

33 2 5 40 45 50 3 18 8 0 204

2010

2020 total in % 45 16 10 3 10 3 45 16 75 26 65 23 3 1 18 6 15 5 2 1 288

Share of Renewable Energy Sources In the Netherlands

In EU countries CO2 reduction Kyoto

1,20%

target

6%

target

10%

12% Period 2008-2010

In the Netherlands

From

In EU countries

From

6% 8%

From 1995

18%

White paper (impr.energy efficiency)

Green paper

Maintaining security of supply

reduction reduction

DoA 20-6-2002

Dutch pulverised coal fired power plants with targets to meet the Coal agreement Power plant

Owner

Gelderland 13

Electrabel

Amer 8 Amer 9 Borssele 12

Essent Essent EPZ

Maasvlakte 1 Maasvlakte 2 Hemweg 8

E.ON E.ON Reliant Energy

Totaal Buggenum Coal gasifier Total

NUON

MWe/ MWth

Eff. Operation CO2 reduction Biomass % since Kt CO2 MWe Kton/y 602 38,0 1983 466 74 335

645/250 600/350 403

40,0 41,3 40,0

1981 1994 1988

931

147

665

310

49

225

518 518 630

40,6 40,6 42,3

1989 1988 1995

805

128

575

488

77

350

3.000 200

475 28

2.150 360

3.200

503

2.510

3875 253

1994

4028

Assumptions - Based on 7500 operating hours/year (otherwise correction) - Average LHV(ar) of the biomass = 15 GJ/ton - Coal substitution = 94 kgCO2/GJth

Additional plans taken from the EIR's (environmental impact reports) Eemshaven Amer Borsele Maasvlakte

Electrabel Essent EPZ EON

Gasification of sewage sludge and gas in GT's

Vathorst

Remu

Biomass Combined cycle with motor

Existing Cuijk Existing Lelystad

Essent NUON

CFB combustion of real biomass Combined cycle

Total Biomass total required in kton/y.

Biomass (+SRF?) Biomass (+SRF?) SRF + Biomass

120 600 400 300 30 200 20 1.670 4.180

20-6-2002

INTEGRATION OPTIONS WITH A COAL FIRED POWER PLANT Stack

Stack

Coal fired Power Plant Coal

Coal mills

Burners Existing

Grinding Optional

Direct feed

Burners New

Fuelgas cooling and clean-up

CFB Combustion

Bottom ash

Steamturbine generator cycle

Fluegas treatment semi-dry system

Fly ash

Waste water treatment

Bottom ash

Existing BLA

Description

Notes

1 2 3 4 5 6 7 8 9 10 11 N0 N1 N2 N3 N4

Desulpherisation plant

Boiler

Pyrolyses oil CFB Gasifier

Elektrofilters

Unit

Fly ash

Electricity

Gypsum

Notification as part of the agreement Co-firing Stand-alone >20MWth Clean Dirty Clean Dirty 6%O2 6% O2(N0) 6% O2 11% O2 20 5 20 5 200(N4) (N4) (N4) (N4) 200 40 200 40 10 10 1 1 50 50 0,015 0,05 (N3) 0,05 10 10 0,15(N2) 0,5 0,1 0,1

11% O2 mg/nm3 Dust 5 mg/nm 3 NO(asNO2) 70 mg/nm3 SO2 40 mg/nm3 HCl 10 mg/nm3 HF 1 mg/nm3 CO 50 mg/nm3 CD + Tl mg/nm3 Hg (asHg) 0,05 mg/nm3 CxHy(volatiles) 10 Heavy metals(N1) mg/nm3 1(N1) PCDD/PCDF ngTEQ 0,1 In case of mixing application 11% O2 Heavy metals As. Cd, Co, Cr, Cu, Mn, Ni, Pb, Sb, Se, Sn, Te, V Heavy metals As, Co, Cr, Cu, Mn, Ni, Pb, Sb, V Input req't at 10% different. Gasunit 0,01 mg/nm3 at 11%O2 No limit in case of NOx trading. However limits are in discussion Emissions from power plant to be calculated with mixing rule Limits derived from LCP 2000/76/EG and WID 2001/80/EG

Set-up for the classification work Limits as set by the notification (separate for clean and dirty fuels) No corrosion and agglomeration

DeNOx catalyst degradation ??? Limits as set by the notification DeSOx

Fuel suppliers Various methods

Parties cooperation to set up of a system. (iterative)

ESP Boiler Gasifier.

Combustion installation

Gascleaning

Bottom ash Fly ash Eural req't

Bottomash Fly ash

Bottom and fly ash

Gypsum

flow shall remarkeble

AfvalwaterLozingseisen Red == requirements from the operation of the power plant Blue == requirements from the emission limits DoA 20-6-2002

RELIANT ENERGY Nr.

1 2 3 4 5

6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66

Element/ Unit Description C wt% dry H wt% dry O wt% dry N wt% dry S wt% dry Cl wt% dry F wt% dry Ash wt% dry Total Moisture wt% ar Ash wt% dry Volatile matter wt% dry Fixed carbon wt% dry Total LHV MJ/kg ar LHV MJ/kg dry Macro elements Al wt% dry Ca wt% dry Fe wt% dry K wt% dry Mg wt% dry Na wt% dry P wt% dry Si wt% dry Ti wt% dry Micro elements Ag mg/kg dry As mg/kg dry B mg/kg dry Ba mg/kg dry Be mg/kg dry Br mg/kg dry Cd mg/kg dry Ce mg/kg dry Co mg/kg dry Cr mg/kg dry Cs mg/kg dry Cu mg/kg dry Eu mg/kg dry Ge mg/kg dry Hf mg/kg dry Hg mg/kg dry I mg/kg dry La mg/kg dry Mn mg/kg dry Mo mg/kg dry Ni mg/kg dry Pb mg/kg dry Rb mg/kg dry Sb mg/kg dry Sc mg/kg dry Se mg/kg dry Sm mg/kg dry Sn mg/kg dry Sr mg/kg dry Te mg/kg dry Tl mg/kg dry Th mg/kg dry U mg/kg dry V mg/kg dry W mg/kg dry Zn mg/kg dry Sulphates Cyanides PAHS (total) --> Needed for

Needed to know for; A B C D E F G H I

x x ? x

x

DoA 20-6-2002 Max limit for conversion in

Analysis J K

Analysis method

Detection limit Cost

Priority

Direct in boiler

x x x x x x

x x x x

x

x x x x x x x x x x x x x

?

x

x x x x x x x

x x x x x x x x x x x1) x x x x x x x x x x x x

?

x x x x x x x x x x x x x x x x x x

?

? ? ? ?

? x x x x x x x x x x

x

x x

x x

?

x

x x x x x x x x x x x x x x x x x A B C E D F G H I

J K Why this?

Corrosion Lifetime SCR catalyst Critical for bottom/flyash EURAL

Automatically deleverd with INAA method. Carcinogenic + ARBO (=V) Besluit Stortverbod Afvalstoffen (27 juni 1995). BVA = Besluit Luchtemissie Afvalverbranding. Bouwstoffenbesluit gebonden spoorelementen

Gasification

Incineration

Nr.

67 68 69 70 71 72

Element/ Description Al/Si ratio Al2O3 CaO Fe2O3 K2O MgO Na2O P2O5 SiO2 TiO2 SO3 CO2 Cl Pb Cd Cu Hg Cr

Unit

Needed to know for; A B C D E F G H I

J K

Analysis

wt %(ash) wt %(ash) wt %(ash) wt %(ash) wt %(ash) wt %(ash) wt %(ash) wt %(ash) wt %(ash) wt %(ash) wt %(ash) wt %(ash) wt %(ash) wt %(ash) wt %(ash) wt %(ash) wt %(ash) wt %(ash) wt %(ash) Ash deformation temperature Initial deform. °C Softening °C Hemispherical °C Fluid °C Morphology Shape kg(ar)/m3 Bulk density A B C E D F G H I

J K

Analysis method

Max limit for conversion in Detection limit Cost

Priority

INAA = instrumental neutron activation analysis (no dissolution required > low cost, high accuracy)

Direct in boiler

Gasification

Incineration

Annex 12.

Country report – USA, by Larry Baxter

Country Report: USA Larry Baxter, Søren Kær, Matt Hall Brigham Young University Provo, UT 84602 June 20, 2002

Outline • Overall trends in US • Cofiring moving toward commercial rather than research support • Gasification and pyrolysis increased research attention • Significant reorganization of DOE and other major support organizations

• Modeling • Grates, pcs, etc. • Deposition

• Corrosion • Ash Utilization

1

Previous DOE Structure Biomass was here

New DOE Structure Biomass is now here

2

Consequences for Biomass • Includes OPT/ Biopower, OTT/ Biofuels, OIT/ Black liquor gasification, OIT Agriculture and black liquor from OIT / Forestry. • Biofuels program essentially eliminated. • Large reduction in combustion & cofiring efforts (deemed as commercially viable). • Increased attention on gasification and pyrolysis.

Other US Developments • Broad (Denise Swink) and specific (Ray Costello) reviews of DOE biomass programs presented earlier in this meeting. • Modular systems review presented by NREL (Rich Bain). • DOE support for EPRI and NETL cofiring programs completed/terminated. • BYU has nearly completed review of over 40 US-based cofiring demonstrations, which will be available (possibly through this task) shortly. • A few technical developments follow.

3

US Energy Policy • Realistic path to CO2 reductions with achievable goals. • Taxpayer vs. ratepayer. • Impacts of other policy and economic decisions (nuclear power, natural gas). • Energy crops vs. residues.

Fuel Characterization Scheme

Hydrogen/Carbon

2 1.5 1 Selected Biomass Softwood Lignin Hemi-/cellulose

0.5

Hardwood Lignin Grass Lignin Lipids

0 0

0.2

0.4 0.6 Oxygen/Carbon

0.8

1

4

Biomass Chemical Characterization 1.0 0.9 Mass Fraction

0.8 Other (Lipid?) Protien Lignin HemiCellulose Cellulose

0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 Oak

Spruce

Straw

Temperature / C

Droplet inner temperature @ 30 Hz 1500 1400 1300 1200 1100 1000 900 800 700 600 500 400 300 200 100 0 0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

Time / s

5

Required Aerating Agent 2.5

Pure Cement Class C Fly Ash (25%)

oz/100 lbs cement

2

Class F Fly Ash (25%) Co-fired Fly Ash (25%) (10% switchgrass) Co-fired Fly Ash (25%) (20% switchgrass)

1.5

1

0.5

0

Set Time Delayed by Fly Ash 3500

Pure Cement

Resistance (psi)

3000

Class C Fly Ash (25%)

2500

Co-fired Fly Ash (25%) (20% switchgrass) Co-fired Fly Ash (25%) (10% switchgrass)

2000 1500 1000 500 0 1

2

3

4

5

6

7

8

Elapsed Time (hrs)

6

Fluxural Strength Unaffected 10.00 9.00

Flexural Strength (kips)

8.00 7.00 6.00

Pure Cement

5.00

25% Class C Fly Ash 4.00

25% co-fired biomass (10% switchgrass) 25% co-fired biomass (20% switchgrass)

3.00 2.00 1.00 0.00

Compressive Strength Variations 8000

100% Cement

7000

75% Cement 25% Class C Fly Ash

6000

psi

5000 4000

75% Cement 25% Class F Fly Ash 75% Cement 25% co-fired biomass (10% switchgrass) 75% Cement 25% co-fired biomass (20% switchgrass)

3000 2000 1000 0 1 day

3 day

7 day

28 day

56 day

91 day

7

Oxygen Isosurfaces

BL mechanisms Inertial deposition flux [g/m2/h]

BL deposition flux [g/m2/h]

8

Vapor deposition Vapor deposition flux [g/m2/h]

Fuel Properties Predict Corrosion

Increasing Time

9

Stoichiometry Affects 2

0.1

Mole Fraction

8 6 4

2

0.01

T = 450 °C Gas Phase H2 O CO2 H2 O2 CH4 CO

8 6 4

2

0.001 0.6

0.8

1.0

1.2

1.4

Stoichiometric Ratio

Oxidizing Conditions Favor Sulfates -3

25x10

12

Mole Fraction

8 15

NaCl Na2SO 4 Na2SO 4(l)

6

10

Mole Fraction x 10

10

20

4 5

2

0

0 0.6

0.8

1.0

1.2

1.4


10

Reducing Conditions Favor Chlorides 600

0.25

500 400 NaCl FeCl2 CaCl2

Moles

0.15

0.10

300

Moles x 10

0.20

200 0.05

100

0.00

0 0.6

0.8

1.0

1.2

1.4


11

Annex 13.

Country report - Norway, by Øyvind Skreiberg

The total annual theoretical biomass production in Norway amounts to about 400 TWh in gross energy units. Of this, 30 TWh is regarded as technically possible for energy utilisation, whereof about half of this is utilised today. Utilisation of the other half (mainly low quality biomass fractions such as forest residues, crop residues, straw, landfill gas, manure) is mainly an economical question. In this respect one should keep in mind that the net Norwegian annual electricity production by hydropower is about 120 TWh (equivalent to about 33000 MW) and that the electricity price in Norway is rather low compared to other European countries. About 30 TWh of the electricity produced is used for direct heating! The official goal in Norway is an increase in the heat production from biomass, heat pumps and waste heat of 4 TWh within 2010 compared to 2000. This is a moderate goal, especially compared to the EU goal for the same period. See our Handbook for further information about the Biomass Energy situation in Norway.

The Norwegian Government plans to ratify the Kyoto protocol in August, and the Kyoto protocol is a driving force for the increase of Biomass for energy use in Norway. To meet our Kyoto obligations with respect to reduction of CO2 equivalents emitted to the atmosphere several actions are recently planned/suggested by the government: • • • • • • • • • •

Extended CO2 taxation Onshore electrification of offshore installations Reduced use of mineral oil Import taxes on HFK/PFK Reduced CH4 emissions from landfills Increased landfill tax Increased combustion of combustible MSW fractions Biodiesel mix with diesel Bioethanol Water based heating

More information can be found at these www-addresses (unfortunately mainly in Norwegian): http://www.stortinget.no/inns/inns-200102-240.html http://www.enoknorge.no/ http://www.enova.no/ An evaluation of implementation projects financially supported by the government has recently been made and shows that 2.5 TWh increased heating capacity has been built during the last 5 years based on both MSW, biomass, waste heat, heat pumps and other minors. Of a total of 808 applications 262 projects was granted financial support. 49 of these projects were stopped for various reasons. A total of 425 millions NOK (about 50 millions EUR) was given in financial support to these projects. The average heat production in each project was about 10 GWh. From an economical point of view, 36% of the overall heat production in all supported projects was in the MSW projects, while these received only 22% of the overall financial support. For the biomass projects the numbers are 26% and 40% respectively. Hence, in

general the need for financial support to biomass projects is larger compared to MSW projects. Activities in Norway on biomass combustion/gasification/pyrolysis are mainly located at the Norwegian University of Science and Technology. Several Ph.D. studies on aspects connected to biomass use for energy purposes have been performed or are in progress. Recently, two Ph.D. studies were finished: • •

Maria Barrio (2002). Experimental investigation of small-scale gasification of woody biomass. Morten Fossum (2002). Biomass gasification – Combustion of gas mixtures.

Information on these theses is enclosed below. Other ongoing Ph.D. studies in the biomass area are connected to: • Hot gas cleaning • Evolution of primary N-species from MSW fractions • Catalytic upgrading of pyrolysis oil • Gasification in combination with Solid Oxide Fuel Cells (SOFC) Our laboratory at the Institute of Thermal Energy and Hydropower (http://www.tev.ntnu.no/) is quite unique in Norway and the experimental equipment has recently been upgraded with a new FTIR and RAMAN laser system, and an advanced fixed bed reactor for well controlled experimental studies is now being built. SINTEF Energy Research (http://www.energy.sintef.no/uk_index.asp) takes care of the more applied/commercial research in the biomass area and is involved in projects with major companies within the MSW/biomass area in Norway. Much of the focus both at SINTEF and NTNU is now at CO2-free power production and the “Hydrogen Society”. Hence, rather long term focus ranging from overall system studies to very fundamental studies. The Nordic Energy Research Programme, which have been active for many years, also with a separate group on biomass combustion, will continue also for a new four year period (20032006). However, major changes are in progress. Even though, the biomass group will continue its work also within the new program structure. Nordic Energy Research Programme link: http://www.nordisk.energiforskning.org/

BIOMASS GASIFICATION COMBUSTION OF GAS MIXTURES

by Morten E. N. Fossum A thesis submitted to The Norwegian University of Science and Technology for the degree of Doktor Ingeniør

The Norwegian University of Science and Technology Faculty of Engineering Science and Technology Department of Thermal Energy and Hydropower May 2002

Report no: NTNU: 2002:42 ITEV: 2002:06 Classification Open

The Norwegian University of Science and Technology POSTADRESSE NTNU INSTITUTT FOR TERMISK ENERGI OG VANNKRAFT Kolbjørn Hejes vei 1A N-7491 Trondheim - NTNU

TELEFONER Sentralbord NTNU: Instituttkontor: Vannkraftlaboratoriet:

TELEFAX 73 59 40 00 73 59 27 00 73 59 38 57

Title of report GASIFICATION OF BIOMASS – COMBUSTION OF GAS MIXTURES

Instituttkontor: Vannkraftlaboratoriet:

73 59 83 90 73 59 38 54

Date 10.04.2002 No. of pages/appendixes 173

Author Morten E. N. Fossum

Project manager Johan E. Hustad

Division Faculty of Mechanical Engineering Department of Thermal Energy and Hydropower ISBN no. 82-471-5437-4

Project no. Price group

Abstract The work presented in this study is primarily experimental and covers the following two main areas; gasification of biomass and combustion of gas mixtures. The work on biomass gasification includes the design of a laboratory scale gasification unit and integration with a gas engine with the necessary equipment for gas cooling and filtration. The performance of both the gasifier and the integrated system is documented in three enclosed papers. The work on gas combustion covers mainly experimental studies of jet diffusion flames with respect to NOx formation and emission, flame geometry and thermal radiation, flame stability and laminar burning velocities. The gas mixtures investigated are low calorific value (LCV) gases, typically from biomass gasification, and mixtures of natural gas and LCV gas. From the experimental data found in this study new correlations for prediction of NOx emission, flame geometry, thermal radiation and laminar burning velocity are suggested. The novelty of this work is mainly related to the investigation of combustion characteristics of gas mixtures. Few data has previously been published on combustion characteristics of gas mixtures similar as found from biomass gasification. For mixtures of LCV gases and natural gas no previous publications have been found which covers the topics presented in this study. The mixed-fuel operation of a gas engine presented in this thesis also represents a novelty compared to documented operation of engines with product gas from biomass gasification.

Group 1 Group 2 Selected by author

Indexing Terms: English Bioenergy

Indexing Terms: Norwegian Bioenergi

Gasification

Gassifisering

Gas mixtures

Gassblandinger

Combustion

Forbrenning

TABLE OF CONTENT PREFACE

1

INTRODUCTION

2

BIOMASS GASIFICATION

7 11

2.1 Gasification processes 2.1.1 Fixed bed gasification. 2.1.1.1 Fixed bed, updraft gasification 2.1.1.2 Fixed bed, downdraft gasification 2.1.1.3 Fixed bed, crossdraft gasification 2.1.2 Fluidised bed gasification 2.1.3 Other gasification processes. 2.1.4 Characteristics of gasification processes

12 13 13 14 15 16 16 17

2.2

19

3 3.1

Design of a laboratory scale gasifier integrated with a gas engine

COMBUSTION OF GAS MIXTURES Low calorific value gases

22 22

3.2 Combustion characteristics and problems 3.2.1 Lower heating value and flame temperatures 3.2.2 Flame geometry and thermal radiation 3.2.3 Laminar burning velocity and flame stability 3.2.4 Pollutant emission

23 23 24 25 26

3.3 Improvement of the combustion characteristics 3.3.1 Co –combustion applications

27 31

3.4 The use of natural gas and low calorific fuel gas mixtures – discussion and recommendations

34

4 A SMALL-SCALE STRATIFIED DOWNDRAFT GASIFIER COUPLED TO A GAS ENGINE FOR COMBINED HEAT AND POWER PRODUCTION 44 5 OPERATIONAL CHARACTERISTICS OF A SMALL-SCALE STRATIFIED DOWNDRAFT GASIFIER

60

6 EMISSIONS AND OPERATIONAL EXPERIENCES FROM A GAS ENGINE FIRED WITH LOW CALORIFIC VALUE GAS AND NATURAL GAS MIXTURES 69 7 NITRIC OXIDE EMSISSION FROM DILUTED CH4/CO/H2 JET DIFFUSION FLAMES 8 NITRIC OXIDE FORMATION IN JET DIFFUSION FLAMES OF CH4/H2/CO MIXTURES

77 103

9 EFFECTS OF METHANE ENRICHMENT OF LOW CALORIFIC VALUE GASES ON FLAME GEOMETRY AND THERMAL RADIATION FROM DIFFUSION FLAMES 110 10 STABILITY AND DYNAMIC DEVELOPMENT OF METHANE ENRICHED LOW CALORIFIC VALUE GAS FLAMES

144

11 LAMINAR BURNING VELOCITIES OF INERT DILUTED MIXTURES OF METHANE, HYDROGEN AND CARBON MONOXIDE 152 12 OVERALL CONCLUSIONS AND SUGGESTIONS FOR FURTHER WORK 171

EXPERIMENTAL INVESTIGATION OF SMALL-SCALE GASIFICATION OF WOODY BIOMASS

by Maria Barrio

A thesis submitted to The Norwegian University of Science and Technology for the degree of Doktor Ingeniør

May 2002 The Norwegian University of Science and Technology Faculty of Mechanical Engineering Department of Thermal Energy and Hydropower 7491 Trondheim, Norway

Report no: 2002:05 Classification Open

The Norwegian University of Science and Technology POSTADRESSE NTNU INSTITUTT FOR TERMISK ENERGI OG VANNKRAFT Kolbjørn Hejes vei 1A N-7491 Trondheim - NTNU

TELEFONER Sentralbord NTNU: Instituttkontor: Vannkraftlaboratoriet:

TELEFAX 73 59 40 00 73 59 27 00 73 59 38 57

Title of report

Instituttkontor: Vannkraftlaboratoriet:

73 59 83 90 73 59 38 54

Date May 2002 No. of pages/appendixes

EXPERIMENTAL INVESTIGATION OF SMALL-SCALE GASIFICATION OF WOODY BIOMASS Author s)

204/32 Project manager (sign.)

Maria Barrio Division

Johan E. Hustad Project no.

Faculty of Engineering Science and Technology Department of Thermal Energy and Hydropower ISBN no.

Price group

82-471-5435-8 Abstract A small-scale stratified downdraft gasifier has been built and operated under stable conditions using wood pellets as fuel and air as gasification agent. The problems observed during the preliminary experiments have been described and explained; they are mainly related to the stability of the process. The stable operation of the gasifier has been characterised by the gas composition and the product gas tar and particle content. The biomass feeding rate has varied between 4,5 and 6,5 kg/h. The CO content of the product gas (23-26 % vol.) is higher than in similar gasifiers and the H2 content has been found to vary 3 between 14 and 16 % vol. The tar content in the product gas (ca. 3 g/Nm ) is rather high compared with similar gasifiers. The temperature profile, together with other relevant parameters like the air-excess ratio, the air to fuel ratio and gas to fuel ratio have been calculated. The experiments show that the air excess ratio is rather constant, varying between 0,25 and 0,3. Experiments have been conducted with a gas engine using mixtures of CH4, CO, H2, CO2 and N2 as a fuel. NOx and CO emissions are analysed. The char gasification process has been studied in detail by means of Thermogravimetric Analysis. The study comprises the chemical kinetics of the gasification reactions of wood char in CO2 and H2O, including the inhibition effect of CO and H2. A kinetic model based on Langmuir-Hinshelwood kinetics has been found which relates the mass loss rate to the temperature, gas composition and degree of conversion for each reaction. The ratio CO/CO2 has been found to be a relevant parameter for reactivity. The gasification experiments in mixtures of CO2 and H2O give reasons to believe that the rate of desorption for the complex C(O) varies depending on the gas mixture surrounding the char. It has been found that if the experimental data are obtained from separate H2O/N2 and CO2/N2 experiments, the reactivity of the char in mixtures of CO2 and H2O can be fairly predicted.

Group 1 Group 2 Selected by author

Indexing Terms English Heat Engineering

Indexing Terms Norwegian Varmeteknikk

Solid Fuels

Faste brensler

Biomass

Biomasse

Gasification

Gassifisering

Reactivity

Reaktivitet

TABLE OF CONTENTS ACKNOWLEDGMENTS………………………………………………………………………………………………………… i TABLE OF CONTENTS………………………………………………………………………………………………………… iii LIST OF FIGURES……………………………………………………………………………………………………………… v LIST OF TABLES………………………………………………………………………………………………………………… vii SUMMARY…………………………………………………………………………………………………………………………… ix 1. INTRODUCTION AND BACKGROUND…………………………………………………………………………… 1 1.1 Objectives of the work…………………………………………………………………………………………… 1 1.2 Thesis overview……………………………………………………………………………………………………… 1 1.3 Biomass as an energy source………………………………………………………………………………… 2 1.3.1 Biomass composition and types…………………………………………………………………… 2 1.3.2 Comparison with other fuels………………………………………………………………………… 5 1.3.3 Biomass production and costs……………………………………………………………………… 9 1.4 Thermochemical conversion processes………………………………………………………………… 13 1.4.1 Pyrolysis or devolatilization…………………………………………………………………………… 15 1.4.2 Gasification…………………………………………………………………………………………………… 17 1.4.3 Combustion…………………………………………………………………………………………………… 19 1.4.4 Liquefaction…………………………………………………………………………………………………… 20 1.4.5 Comparison and interaction between the different conversion processes… 20 1.5 Biomass gasification……………………………………………………………………………………………… 21 1.5.1 Gasification reactions…………………………………………………………………………………… 21 1.5.2 Gasification processes…………………………………………………………………………………… 22 1.5.3 The water-gas shift reaction………………………………………………………………………… 31 1.5.4 Types of reactor…………………………………………………………………………………………… 32 1.5.5 Gas conditioning…………………………………………………………………………………………… 35 1.5.6 Pressurized gasification………………………………………………………………………………… 39 1.6 Power generation from biomass gasification………………………………………………………… 41 1.6.1 Introduction…………………………………………………………………………………………………… 41 1.6.2 Types of cycle………………………………………………………………………………………………… 41 1.6.3 Gas turbines for product gas………………………………………………………………………… 42 1.6.4 Gas engines for product gas………………………………………………………………………… 48 1.6.5 Emissions……………………………………………………………………………………………………… 49 1.7 Challenges and prospects for biomass gasification……………………………………………… 50 1.8 References……………………………………………………………………………………………………………… 50 2. THE SMALL-SCALE DOWNDRAFT GASIFIER………………………………………………………………… 57 2.1 Introduction and background………………………………………………………………………………… 57 2.2 Gasification agent…………………………………………………………………………………………………… 59 2.3 Biomass feeding system………………………………………………………………………………………… 59 2.4 Reactor size and design………………………………………………………………………………………… 60 2.5 Operation pressure………………………………………………………………………………………………… 61 2.6 The CHP plant………………………………………………………………………………………………………… 61 2.7 Work progress………………………………………………………………………………………………………… 62 2.8 Filtration and other upgrading processes……………………………………………………………… 62 2.9 Safety considerations……………………………………………………………………………………………… 64 2.10 Gasifier calculations……………………………………………………………………………………………… 65 2.10.1 Mass and energy balances………………………………………………………………………… 65 2.10.2 Evaluation of stable operation…………………………………………………………………… 68 2.10.3 Gas chromatography…………………………………………………………………………………… 70 2.11 Summary of papers I, II and III………………………………………………………………………… 73 2.12 References…………………………………………………………………………………………………………… 74 Paper I…………………………………………………………………………………………………………………………… 75 Paper II………………………………………………………………………………………………………………………… 93 Paper III…………………………………………………………………………………………………………………………103

iii

3. REACTIVITY STUDIES ……………………………………………………………………………………………………111 3.1 Introduction…………………………………………………………………………………………………………… 111 3.1.1 Objectives………………………………………………………………………………………………………112 3.2 Experimental information……………………………………………………………………………………… 112 3.2.1 Experimental apparatus…………………………………………………………………………………112 3.2.2 Calibration procedures……………………………………………………………………………………115 3.3 Relevant reactivity aspects…………………………………………………………………………………… 121 3.3.1 Pyrolysis conditions……………………………………………………………………………………… 121 3.3.2 The effect of the degree of conversion…………………………………………………………121 3.3.3 Influence of ash components…………………………………………………………………………122 3.3.4 The presence of O2 ……………………………………………………………………………………… 130 3.3.5 Heat of reaction for gasification reactions……………………………………………………131 3.3.6 The influence of the experimental apparatus………………………………………………132 3.4 Summary of papers IV, V and VI……………………………………………………………………………134 3.5 References……………………………………………………………………………………………………………… 136 Paper IV………………………………………………………………………………………………………………………… 137 Paper V……………………………………………………………………………………………………………………………155 Paper VI………………………………………………………………………………………………………………………… 171 4. CONCLUSIONS AND RECOMMENDATIONS FOR FURTHER WORK……………………………… 185 4.1 The small scale downdraft gasifier…………………………………………………………………………185 4.2 Reactivity studies……………………………………………………………………………………………………186 4.3 Connection between the experimental work with the gasifier and the reactivity studies…………………………………………………………………………………………………… 188 APPENDIX APPENDIX APPENDIX APPENDIX

A: PICTURES…………………………………………………………………………………………………… 191 B: PROCEDURES……………………………………………………………………………………………… 201 C: TECHNICAL DATA…………………………………………………………………………………………209 D: EXPERIMENTAL RECORD…………………………………………………………………………… 215

iv

Annex 14.

Country report – Switzerland, by Thomas Nussbaumer

Biomass Combustion Activites in Switzerland 2002 Thomas Nussbaumer Verenum, Zürich

Swiss Delegate in IEA Bioenergy Task 32 on behalf of the Swiss Federal Office of Energy Verenum

1 Research & Development • • • • •

NOx Reduction, Air & Fuel Staging Process Control Aerosol Formation Pellet Production (Gasifer + IC engine, Tar Conversion, GC)

2 Implementation • • • •

Quality Assurance (QA) System Optimisation (SO) Investigations on Ash Utilisation from native Wood Implementation of Type Test for Boilers

3 IEA Activity •

Seminar on Aerosols, here: Poster V2.162 Verenum

1 Research and Development (1) Influence on particulate emissions

dN/dlog dp [1/Ncm3] (13% O2)

Project: Verenum, Müller AG, EMPA Project Manager: M. Oser (Verenum) –> Formation mechanisms, influences, and primary measures –> Particle reduction can be achieved with specific operation (see Paper V 2.140)

[Oser et al. 2000]

3E+8

Lambda = 3.0 Lambda = 1.8 Lambda = 1.4 2E+8

1E+8

0E+0 10

100

1000

Elektrischer Mobilitätsdurchmesser dp [nm]

Further information: Poster V2.140 at this conference Verenum

1 Research and Development (2) Particulate emissions from different furnace types Project: Ökozentrum Langenbruck (CH), Lulea (S), VTT (F) Project Manager CH: Ch. Gaegauf –> Comparison of particulate emissions from different furnace types –> Influence of pulsating combustion and load

[Gaegauf et al. 2002]


1 Research and Development (3) Wood heating for low energy buildings Project: Ökozentrum Langenbruck and HTA Luzern Project Manager: Ch. Gaegauf –> Optimisation of heat distribution and storage for low energy houses

[Gaegauf et al. 2002]


1 Research and Development (4) Pellet production Project: Verenum, Bürli AG Project Manager: T. Nussbaumer (Verenum) Aim –> optimization of pellet production (energy demand, cost) –> influence of natural additives on production, composition, and emissions

Motivation: Potential for pellets in Switzerland 180 000 t/a saw dust and similar wood res. = 3,2 PJ/a = 0,37% of total tnergy consumption = 45‘000 households with 4 t/a (2000 l Öl/a)

Further information: Download: www.energieforschung.ch Verenum

Pellet standards Ordinance on Air Pollution Control (OAPC) (corresponds to TA Luft (GER)): No additives

DIN / SN Abrasion unlimited Additives prohibited Heavy metals limited

ÖNORM Abrasion limited Additives allowed no limits

Verenum

Pellet production Abluft Gewebefilter Siebanlage Pellets

Abgas Zyklon

Luft Öl

Förderschnecke

Trockner Zyklon

Presse

Sägemehl

Schlagmühle

Bettkühler

Absackanlage

Big bagStation

Silo

Hygroskopy .... and influence of storage Detailed results in report [Hasler & Nussbaumer 2001]: Download: www.energieforschung.ch Verenum

Results on abrasion of dust from pellets Base

Bürli Pellets ohne Presshilfsmittel (V1; Standard) Bürli Pellets ohne Presshilfsmittel (Standard)

Bark

Bürli Pellets ohne Presshilfsmittel (mehr Rinde; V8) Bürli Pellets mit Presshilfsmittel 1 (V2) Bürli Pellets mit Presshilfsmittel 1 (V7) Bürli Pellets mit Presshilfsmittel 1 (mehr Rinde) Bürli Pellets mit Presshilfsmittel 2 (V3) Bürli Pellets mit Presshilfsmittel 3 (V4) Bürli Pellets mit Presshilfsmittel 4 (V5) Bürli Pellets mit Presshilfsmittel 4 (V9) Bürli Pellets mit Presshilfsmittel 5 (V6) 0.0

1.0

2.0

3.0

4.0

5.0

6.0

Abriebfestigkeit (60 s) [Gew.-%]

Verenum

Combustion behaviour Emissions including particle size distribution Efficiency Ash slagging Bürli Pellets ohne Presshilfsmittel (V1), Vollast, Partikel-Anzahlvert Datum: 9.8.01

Anlage: Std

Code:

1 hi

Power: 14.6

1.2E+08

S F S G R

NC = dN/dlog(dp) [Ncm^-3, @ 13% O2 ]

1.0E+08

M 1

8.0E+07

L 6.0E+07

4.0E+07

2.0E+07

0.0E+00 10

15

100

550

1000

Partikeldurchmesser [nm]

Verenum

LCA

[BUWAL 315, 2000; Hasler und Nussbaumer 2001] Ecological Scarcity Method Base case of greenhouse effect(Oil, effect Gas)

Pellet (