Effects of gasifying conditions and bed materials on fluidized bed steam gasification of wood biomass

The effect of steam gasification conditions on products properties was investigated in a bubbling fluidized bed reactor, using larch wood as the starting material. For bed material effect, calcined limestone and calcined waste concrete gave high content of H2 and CO2, while silica sand provided the high content of CO. At 650 °C, calcined limestone proved to be most effective for tar adsorption and showed high ability to adsorb CO2 in bed. At 750 °C it could not capture CO2 but still gave the highest cold gas efficiency (% LHV) of 79.61%. Steam gasification gave higher amount of gas product and higher H2/CO ratio than those obtained with N2 pyrolysis. The combined use of calcined limestone and calcined waste concrete with equal proportion contributed relatively the same gas composition, gas yield and cold gas efficiency as those of calcined limestone, but showed less attrition, sintering, and agglomeration propensities similar to the use of calcined waste concrete alone.