Catalytic biomass gasification: Simultaneous hydrocarbons steam reforming and CO2 capture in a fluidised bed reactor

Tars and CH4 generated from biomass gasification processes contribute significantly to the energy content of the producer gas: catalytic tar and CH4 steam reforming allows to clean the gaseous fuel and improve the H2 yield; in addition, the use of a CO2 sorbent minimises carbon oxides. As a result of the whole process, a H2 rich fuel gas may be obtained. This experimental work is addressed to study the practical feasibility of such concepts, choosing CH4, toluene and 1-methyl naphthalene (1-MN) as biomass gasification key primary products. Ni is used as a catalyst for steam reforming, and dolomite as a sorbent for CO2 capture. Two kinds of catalytic systems are tested as bed material: a mixture of dolomite and commercial nickel catalyst, and a new Ni/dolomite combined catalyst and sorbent. The experimental investigations have been carried out in a fixed bed microreactor and a bench scale fluidised bed reactor rig. Both combinations of catalyst and sorbent are found to be very effective in tar removing, with conversion values near to 100% for the compounds tested; simultaneous CO2 sorption reveals itself as the key process step, improving significantly the performance of the catalytic system that may then decrease considerably after sorbent saturation.