Fluidized bed gasification of biomass
The influence of individual parameters on biomass gasification in a bubbling fluidized bed was studied in the frame of a number of both basic and applied research projects. One of the investigated problems was the influence of catalytically active calcium oxide and inert quartz sand in the fluidized bed of the gasifier during an autothermal gasification of biomass with the use of a mixture of CO2+O2 as a gasifying agent. The influence of calcium oxide in the fluidized bed for the gasification of biomass with this gasifying agent was compared with a commonly used gasifying agent H2O+O2. While the sufficient concentration of catalytic calcium oxide in the fluidized bed was only 50 % when H2O+O2 was used, in the case of CO2+O2, the optimal results were achieved with pure CaO in the fluidized bed. The catalytic effect of CaO in the fluidized bed resulted, in this case, in an 8.7 times lower tar yield in the producer gas and a decrease of the tar dew-point by 124 °C to 71 °C.