Experimental research on model compound reforming of biomass tar to produce H₂-rich gas

The tar model compound (benzene) reforming to produce hydrogen-rich gas was investigated in a fluidized bed, where the steam acts as the gasification medium. The influences of operating parameters on producing hydrogen-rich gas were fully investigated by changing the reactor temperature, the ratio of steam mass to tars mass(S/T) and the bed height; in addition, the effects of various bed materials(catalysts) on the reforming reaction are also focused on in this paper. The reactor temperature was varied from 780℃ to 900℃, S/T from 3.0 to 6.0, and the bed height from 5.0cm to 20.0cm. The experimental results demonstrate that the optimum operating parameters for producing hydrogen-rich gas are the reactor temperature of 860℃~900℃, S/T of 5.0 and the bed height of 15.0cm~20.0cm. Under the condition of optimum operation, the synthesized alkaline earth metal-based catalyst (20CaAl) displays a better catalysis than natural ores(dolomite and limestone). And the modified catalyst SCaFeNiAl based on 20CaAl exhibits a higher catalytic activity with the activation energy of 58.87kJ/mol and pre-exponential factor of 1.36×10⁷h^-1. With SCaFeNiAl, the H₂ content of 67.28%, the H₂ yield of 303.50(g/kg-tar), the tar conversion ratio of 95.93% and the total gas yield of 5.05(m³/kg-tar) are obtained.