Hydrogen Production via Catalytic Steam Reforming of Bio-oil Model Compound in a Two-stage Reaction System

A mixture of several typical model compounds was chosen as the bio-oil model. Hydrogen production via catalytic steam reforming of model bio-oil in a two-stage reaction system was studied in this article. Quartz sand was used in the first-stage fluidized bed reactor for primary steam reforming, and Ni/modified dolomite was chosen as the catalyst in the second-stage fixed bed reactor for deep steam reforming. The main influential parameters, such as temperature, steam to carbon ratio, and weight hourly space velocity, were tested in this work. The optimum conditions on hydrogen production were obtained at 800°C; steam and carbon mole ratio, 12; and weight hourly space velocity, 1 h⁻¹. In addition, there was a comparison between a two-stage reaction system and one-stage fixed bed reactor on the optimum condition. It was concluded that H₂ yield decreased 5.6% in the two-stage reaction system and 9.9% in the one-stage fixed bed reactor after 3 h reaction time; the maximum carbon deposition ratio was 1 and 0.44%, gaseous carbon selectivity dropped from 93.6 and 90.1% to 83.4 and 78.4%. The fresh catalyst as well as used catalyst were analyzed by scanning electron microscopy, which showed that the carbon deposition in the two-stage reaction system is less than that of the one-stage fixed bed reactor.