Steam Gasification of Bio-Oil and Bio-Oil/Char Slurry in a Fluidized Bed Reactor

Abstract

Bio-oil/char mixtures and whole bio-oil from rapid pyrolysis of woody biomass are potential feeds for synthesis gas production via steam gasification. A 7.8 cm diameter, atmospheric pressure, fluid bed gasifier was constructed and operated with either a nickel-containing steam reforming catalyst or silica sand as bed material. Both bio-oil and a slurry of 80 wt % bio-oil and 20 wt % char were tested as feedstocks. Effects of bed temperature, steam to carbon molar ratio, and space velocity on gaseous component yields and carbon conversion are reported for both feedstocks using catalytic and noncatalytic bed material. At the moderate temperatures (<840 °C) of the experiments, carbon conversion is incomplete, and some mixed hydrocarbons are present in the produced gases. Yields of the main gas constituents are compared with an equilibrium model which was modified to correct for these two factors. Observations are made on stability and attrition issues with the catalyst.