Since 2008, the provision of electricity and heat from biomass by thermo-chemical gasification has increased significantly throughout Germany from a few plants to more than 100 decentralized plants in operation [Bräkow10]. The power of these plants, which are mostly heat-controlled and run with wood chips, is mainly between 70-500 Kilowatts. As a result of their size, the nominal power as well as time expenditure for the plant operation, the application of these plants is mainly limited to the industry with an according heat demand technically trained staff. Due to the increasing energetic utilization of biomass, the energy wood market has enormously grown over the last few years in Germany. As a result, rising subscription prices for biogenic energy sources can be observed so that operators of plants running with wood chips are forced to look out for a wider range. On the other hand, there exist large amounts of biogenic residues, waste material and by-products, which have remained widely unused up to now but contain a considerable energetic potential.
The aim of the „Mini Bio-KWK”-Project is to bring a prototype for decentralized gasification wood-residue-pellets for the provision of electricity and heat with a power of 30 Kilowatts thermic/15 Kilowatts electric to series-production readiness. Because of its low power, this fully automatized biomass gasifier is suited for the application in residential buildings and small business. The basis of this enterprise is pilot plant from the Spanner Re2 GmbH Company for the gasification of wood-residue-pellets with an electrical efficiency of 25 %. The concept of this pilot plant was deduced from the wood chip fixed-bed gasifier produced and distributed according to the Joos-procedure since 2008. Due to the field of application, the power of the wood-residue-pellet gasifier is significantly lower than the power of the underlying wood-chip gasifyer.
The scientific and technical aims of the „Mini-Bio-CHP”-Porject are
- the transfer of operation experiences with the gasification of wood chips made so far by the applicant to the prototype running with wood-residue-pellets,
- process-technical adaption and optimization of Spanner Re²’s prototype regarding the different requirements of wood-residue-pellets compared to wood chips for the process as well as
- the conversion of biogenic like residues, waste material and byproducts for the pelletizing according to the guidelines of the conversion process.
The measures for the implementation of the mentioned aims are compiled and implemented by the Spanner Re² Copmpany under scientific attendance of the Unit of Technology of Fuels of the RWTH Aachen University.