FROM ROOT TO SOOT – RESEARCH ON WHOLE BIOMASS PRODUCTION CHAIN

Focus on solid biofuel procurement

technologies

VTT PROSESSIT

VTT

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Versatile research on bioenergy technologies The bioenergy research at VTT covers the whole biomass production and utilisation chain from fuel production and handling to combustion, gasification and liquefaction of biomass fuels including environmental and techno-economic studies. Main research areas are biomass fuel production and handling technologies, fluidised bed combustion, gasification, fast pyrolysis of biomass into liquid biofuel and research on small-scale wood burning appliances. VTT also carries out field measurements at district heating stations and power plants. We are participating in a number of national and other cooperation projects.

More efficient wood, agrobiomass and peat production technologies under development The research area of wood, agrobiomass and peat production at VTT is concentrating on fuel procurement. Our activity focuses on research on indigenous, solid biofuels, such as wood, peat and agro-biomasses. R&D work is carried out in cooperation with peat and wood fuel producers, equipment manufacturers, power plants and research organisations. Research covers both fundamental research and applied studies. We participate in a variety of international research and demonstration projects. Our task is also to create technological solutions and ideas for private companies as well as for public sector. The goal of our research and development work is to develop new efficient machines and methods as well as to decrease harvesting costs of biomass for energy, improve quality of bioenergy, develop pellet production and handling technology and develop methods for fuel ash utilisation as forest fertiliser.

Crushing of logging residue bundles.

Research covers a wide range of biomass fuels The research and development on production and handling technologies include the following biomass fuels: • forest fuels - wood chips, hog fuel and firewood • industrial by-products and residues like bark

sawdust and ash • peat • agrobiomass - reed canary grass and straw The research and development includes: • Fuel production - harvesting technologies and

drying, logistics, storage, transport and transport control

• Refining of biomass into pellets and briquettes • Fuel handling at the plant - crushing and screening • Environmental effects - environmental effects of

biomass fuel production and ash recycling

Train transport of stumps and timber.

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Technology development aims to decrease production costs of wood fuels In Finland the target is to increase the use of forest residues for fuel up to 10 TWh (5 million m3 solid) by the year 2010. Finland has especially large potential for using forest residues for energy production, 25.8–31.6 TWh. The forest fuel potential consists of logging residues and stumps from final felling and small-size wood from thinning and young stands. The use of forest chips for fuel has increased rapidly in Finland. In 1995 the use of forest chips was only 1 TWh. In 2003 the use of forest residues was 4.2 TWh. During the last few years VTT has coordinated Wood Energy Technology Programme in which new technologies for forest chip procurement have been developed to meet market demand and price competitiveness. VTT is developing technology for logging residues and small-size wood harvesting and stump extraction. This work is carried out in cooperation with forest chip producers and manufacturers. VTT has evaluated forest residue chips availability, developed machines and methods. Research work also includes drying and storage of forest residues and small-size wood. We have developed e.g. compacting technology for truck transport of forest residues from forest to power plant. By using the VTT’s compacting technology it is possible to increase the net load of the truck by 50%.

Compacting of logging residues in a truck trailer.

Logging residue pile.

Storage of small-size whole trees. VTT´s main activities in 2004–2006 will concentrate on wood fuels in order to develop more competitive production technologies of small-size wood from thinnings and also to develop extraction of stumps from final felling stands in order to improve the quality of chips made from stumps.

Forest haulage of stumps.

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Firewood quality will be improved In Finland firewood production and use is annually about 6 million m3 (solid). One of VTT’s research and development areas is firewood production. The main target on this field has been to improve firewood quality, to develop the cutting and handling of firewood and to develop packing for delivery to consumers. To improve the quality of firewood, we have made laboratory research on firewood drying. Based on these results a model for firewood drying in open air has been developed. VTT has also carried out research work on firewood drying in different packages in the saw timber dryer. The results have been promising and VTT has started to develop a firewood dryer together with firewood producers. Finnish companies are manufacturing a lot of different firewood chopping and splitting machines from small-scale machines up to very big automatic machines. VTT has measured the capacity and functioning of these machines, and also made a research to find out the best possible package form and size for firewood delivery to consumers.

Drying of firewood in the climate chamber at VTT.

Firewood packages in a saw timber dryer for drying research.

New peat production method meets environmental targets cost-efficiently Finland is the most important producer of fuel peat in the world. Most of the peat is mixed with wood and used in district heat and CHP plants for generating electricity and heat. During the last years the use of fuel peat has been about 25 TWh/a, which is about 6% of the total energy consumption and about 20% of the district heat and CHP production. VTT is the world leading peat research institute with long experience in peat research since 1940. From 1988 to 2003 VTT has coordinated three national research programmes of peat production technology development. The target has been to intensify the capacity of peat production machines and to develop methods in order to decrease harvesting costs. The work has been very successful and the price of peat has remained on the same level for the last twenty years. The peat production technology developed in Finland is even world-wide in a class of its own. One of the results achieved in the programmes is a new pneumatic harvester, which is very efficient and environmentally sound. In the harvester the dust emissions have been eliminated by secondary cyclones.

Peat is dried on asphalt heated by solar panels. In 2003 VTT started a new large peat production development project together with Vapo Oy. Target is to develop a totally new peat production method in order to decrease environmental effects like dust, noise and water emissions in peat production. The new peat production method is estimated to be commercially available in five years.

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Agrobiomass production technology The target is to increase the use of agrobiomass in energy in Finland up to 0.2 TWh by 2005, 0.6 TWh by the year 2010 and 1.4 TWh by 2025. The main agrobiomass raw material sources are reed canary grass (RCG) (Phalaris arundinacea L.) and straw. Cultivation of reed canary grass can take place on fields or on cut-over peat production areas where surface areas are large and harvest can be blended with peat. The techno-economical production potential of reed canary grass and straw is at the most 9.4 TWh/a. This would require cultivation of reed canary grass on 170,000 hectares, of which 15,000 hectares would locate on cut-over peat production areas, and the straw utilisation from 200,000 hectares. Our activity is focused on harvesting technologies, but also the whole production chain including logistics is studied and developed. VTT has especially developed harvesting technology based on loose material for RCG and straw. In this method RCG and straw are chopped on the field and transported to power plant without baling. We are utilising experience of peat production technologies in developing loose harvesting method. This method is economical with short transport distances. RCG plantations benefit also peat production, because reed canary grass can be cultivated for treatment of run-off waters. This has broadened our expertise, not just from harvesting technology, but also on developing water treatment structures.

Baled reed canary grass.

Collecting of reed canary grass to be harvested as loose material for power production. Blending of biomass fuels – challenge for handling technology at power plant The new biomass mixture fuels have created a need for the development of fuel quality control and handling systems on power and heating plants. Research work has concentrated on quality systems and cofiring of different solid biofuels. The work has included development and automation of unit operations of fuel handling and feeding, like receiving stations, sampling, on-line measurements, screening, crushing, fuel silos, conveyor and feeding systems. Also fire safety, as well as occupational healthy and dust problems, have been studied. A pilot scale fuel handling facilities have been constructed, including screening, crushing and feeding equipment. An example of utilisation of the pilot line is the study of two-stage crushing of variety wood fuels. The low costs, efficient feeding, high capacity, tolerance against impurities and low power demand are the main advantages of this crushing method. Both crushing stages can be utilised separately depending on the combustion process.

Two-stage crusher is used for research on variety of wood fuels. Crushing is carried out in two stages. The first phase is preliminary crushing and the secondary phase is the final fine crushing.

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Pellet production and handling technology improves fuel quality About 20 pellet factories are in operation in Finland with annual capacities of from 5,000 to 60,000 tons. Pellet production was almost 200,000 tons in 2003, of which 80% was exported to e.g. Sweden, Denmark and the Netherlands. Domestic consumption was about 25,000 tons and it is growing fast especially in large buildings.

High quality pellets made from pine bark. VTT started several projects on pellet production from wood, straw and peat already in the late 1970s, but while the price of oil was falling and hence the competitiveness of pellets was poor, the projects were stopped. At the moment, VTT is developing pellet production, combustion and handling technology for pellets. Research of pellet production is concentrated on pressing pellets from different materials, especially from “wet” raw materials like forest residues and bark. In the pilot tests raw material has been crushed after drying by utilising VTT’s two-stage crusher’s secondary fine crusher. Crushed material is proved to be suitable for pellet production.

Pellets are lifted to the height of 2,6 m with a spiral-screw.

Handling technology R&D work covers e.g. the conveying of pellets from storage to boiler silo. Research has been carried out on screw - and spiral conveyors and pneumatic conveying system. Spiral conveyor has several advantages: its price is low, it is efficient, flexible and simple in construction. However, its capacity of moving pellets vertically is limited. Ash recycling – wood biomass back to forests Usage and recycling of ashes from power plants fired with peat and wood are becoming more and more actual. Especially wood ash, which contains valuable nutrients, is worth of recycling back to forests as a compensation fertiliser after harvesting of energy wood. Wood ash is especially suitable to nitrogen-rich peatlands. If biosludge from pulp and paper industry is added to wood ash, the use of wood ash can be expanded to mineral soils, where exists lack of nitrogen. We are developing a simple granulation method for co-granulation of ash and biosludge.

Granulating of wood fuel ash. We are also participating in an EU project - RecAsh, which aims to promote the use of wood ashes as a forest fertiliser. It will demonstrate the recycling of ash to forests in Sweden and Finland. Our activity in Finland is focused especially on mixed ashes and the properties of ash in order to clarify when ashes are suitable for spreading into forests, co-utilisation of ash and biosludge together, and developing efficient logistics and enhancing cooperation in ash treatment between different ash stakeholders.

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Selected list of publications in English: Alakangas, E. & Paju, P. Wood pellet in Finland - technology, economy and market. OPET Report 5. Jyväskylä. VTT Energy, 2001. 64 p. + app. 21 p. Bialystok case-study. Climbus project "EU's wood fuuel resources, energy technology market and international bioenergy trade mechanism." Bialystok, Poland. November 2005. 28 p. Biomass fuel production potential in Ukraine. Project report. Tacis project "Support and Development of Renewable Sources of Energy (Biomass) - Ukraine", Task 3 "Assessment of Biomass Market and New Opportunities". Kyiv, June 2006. 87 p. Hakkila, P. Developing technology for large-scale production of forest chips. Wood Energy Technology Programme 1999–2003. Technology Programme Report 6/2004. Final report. Tekes. Helsinki 2004. 99 p. Harvesting technology of logging residues, straw, as well as corn & sunflower residues, for fuel in Ukraine. Project report. Tacis project "Support and Development of Renewable Sources of Energy (Biomass) - Ukraine", Task 3 "Assessment of Biomass Market and New Opportunities". Kyiv, January 2006. 107 p. Leinonen, A. Harvesting Technology of forest residues for fuel in the USA and Finland. Espoo 2004. VTT Research Notes 2229. 132 p. + app. 10 p. Järvinen, T. The influence of increased wood energy utilisation on handling and feeding systems in Finland, Bioenergy 2003, Proc. of the Conference, Jyväskylä, Finland 2.–5.9.2003. p. 268-270. Leinonen, A., Lindh, T., Paappanen, T., Kallio, E. & Flyktman, M. and Hakkarainen, J., Käyhkö, V., Peronius, P., Puuronen, M. & Mikkonen, T. 1998. Cultivation and production of reed canary grass for mixed fuel as a method for reclamation of peat production area. An International Symposium: Peatland Restoration and Reclamation, 14–18 July. Duluth, Minnesota, USA. p. 120–124. Leinonen, A. & Paappanen, T. Fuel peat employs up to 16,000 people in the European Union. Peatlands International 2/2006. pp. 53-57. Lindh, T., Isännäinen, S., Mursunen, H., Rantala, P-R., Ollila, S. & Kaunisto, S. 2003. Processing of wood ash and biosludge from pulp and paper industry for forest fertiliser. Bioenergy 2003, International Nordic Bioenergy Conference 2.–5.9.2003. Proceedings. p. 201–203.

Lindh, T., Kallio, E., Selin, P., Marja-aho, J., Huovinen, J. & Käyhkö, V. 2002. The use of reed canary grass of plantations on cut-over bogs for run-off water purification of peat production. Proceedings of the international peat symposium: Peat in horticulture. Pärnu, Estonia, 3–6 September. p. 37–41. Orjala, M. & Leinonen, A. Renewable bioenergy in Namibia - NamBio. Confidential report. VTT, Espoo, 2006. 23 p. + app. 3 p. Paappanen, T., Leinonen, A., Flyktman, M. & Hillebrand, K. Fuel peat industry in Finland. VTT, Espoo, 2006. 20 p. Ranta, T., Halonen, P. & Alakangas, E. Production of forest chips in Finland. OPET Report 6. VTT Energy, 2001. 58 p. Contacts of Wood and Peat Production Research Mr Arvo Leinonen, D.Sc. (Tech) Peat and wood production technology, Team Leader Mr Ari Erkkilä, Lic.Sc. (Tech.) Small-scale peat and firewood production Mr Kari Hillebrand, Ph.Lic. Drying, storage and handling of biofuels Mr Risto Impola, M.Sc. (Tech.) Harvesting of stumps; Handling technologies Mr Timo Järvinen, M.Sc. (Tech.) Handling technology Mr Markku Kallio, M.Sc. (Tech.) Pellet production and handling technology Ms Tuulikki Lindh, M.Sc. (Tech.) Production of agrobiomasses and ash handling technology Mr Teuvo Paappanen, M.Sc. Feasibility studies, numerical calculations and simulation Mr Matti Virkkunen, M.Sc. (Agr. & For.) Production of forest fuels Mr Jyrki Raitila, M.Sc. (Agr. & For.) Production of forest fuels Other contacts: Ms Satu Helynen, Technology Manager, Energy Technologies Mr Jouni Hämäläinen, Technology Manager, Bioenergy Mr Markku Orjala, Customer Manager, Energy Ms Eija Alakangas, Senior Research Scientist, Technology transfer and bioenergy networks, Solid biofuel standardisation

VTT January 2007

VTT is one of the largest and best-known European research and development units also in the field of bioenergy, especially in forest biomass-based expertise, and developing also distributed energy concepts. VTT´s activities cover the whole bioenergy chain from harvesting and handling of biomass-based fuels to energy production technologies and end-use. VTT with its expertise on bioenergy is in a key position in the development of new technology needed to achieve this goal in co-operation with industry and other stakeholders. Finnish bioenergy technology is well-known globally especially for recovery and utility boilers utilised in forest industry. Advanced combined heat and power production and residential heating are areas of extensive growth.

VTT P.O. Box 1603

(Koivurannantie 1) FI-40101 Jyväskylä, Finland

Tel. + 358 20 722 111 Fax + 358 20 722 2749

http://www.vtt.fi/