Effect of Carbonaceous Deposit on Bed Particles During Rapid Pyrolysis on Gasification Rate of Biomass Char in Fluidized Bed

Gasification characteristics were evaluated for various biomass samples such as softwoods and hardwoods. The authors were pyrolyzed at 1000 degree C in a small scale fluidized bed under rapid heating condition with N2 flow. After keeping 10 min at the temperature, the produced char was gasified with 25% CO2 at 1000 degree C. Char gasification characteristic was investigated by monitoring CO producing rate and the effects of woody biomass species on gasification rate and its time variation were examined. The alumina particles became black which suggests existence of some carbonaceous materials. Then each sample was introduced into the fluidized bed and separately gasified in the same bed. The gasified gas analyses showed that gasification rapidly proceeded for alumina particles only at the first stage of its gasification which explained the peak of gas evolution at low conversion of the continuous in situ pyrolysis/gasification experiments.