Development of biomass gasification technology based on a 3-stage flexible gasifier (FLETGAS)

Summary: The aim of the project consists of developing a gasification system to produce electricity from biomass and wastes, allowing to overcome the two main barriers which fluidized-bed biomass gasifiers currently present: the low conversion of carbon (due to the incomplete conversion of char) and the high tar content of the gas. The new gasification process is based on a reaction system in three main stages: (1) devolatilization and mild partial oxidation in a first fluidized bed, (2) non-catalytic reforming of the gas and (3) filtration of the gas in a moving bed where heterogeneous gasification of the char coming from the first stage is virtually converted. During the char conversion is this third stage the bed material reform the gas providing effective catalyst surface for tar reaction. This system generates a fuel gas fitting the required specifications of a combustion engine with minimum downstream gas cleaning (simple water scrubbing). The proposal consists of the design and construction of a biomass/waste gasification pilot plant of 15 kg/h. With experience acquired in the operation of the plant, a simulation model will be developed enabling to scale up and optimize the process for other biomasses and wastes.