Gasification technologies for heat and power from biomass

A critical review is presented of biomass gasifier systems presently commercially available or under development. Advantages and possible problem areas are discussed in relation to particular applications. Both large and small scale technologies are reviewed. Catalysed by the EC JOULE and AIR programmes, a rather spectacular increase in interest in small scale fixed bed gasification technology, particularly for combined heat and power generation, is noted. Also, co-gasification of biomass and coal attracts interest. Several initiatives are undertaken to raise power from co-combusting producer gas from biomass in conventional power stations. Also combusting producer gas for indirectly heating-up the automotive air for a gas turbine asks for attention. Both counter current fixed bed and fluidized bed gasification for heat applications appear to be commercially available. Gas turbine driven combined heat and power units based on (circulating) fluid bed technology are under development under the EC THERMIE programme at a scale of 10 Mwe. Rapid progress is made in improved gas cleaning technology, particularly also under the JOULE and ATR Programmes of the European Commission. An increasing number of pilot plant test facilities is available for testing the gasification of difficult fuels in various integrated systems.