Potassium catalytic hydrogen production in sorption enhanced gasification of biomass with steam

摘要

Sorption enhanced gasification (SEG) of biomass with steam was investigated in a fixed-bed reactor to elucidate the effects of temperature, catalyst type and loading on hydrogen production. K_2CO_3, CH_3COOK and KCl were chosen as potassium catalyst precursors to improve carbon conversion efficiency in gasification process. It was indicated that from 600 ℃ to 700 ℃, the addition of K_2CO_3 or CH_3COOK catalyzed the gasification for hydrogen production, and hydrogen yield and carbon conversion increased with increasing catalyst loadings of K_2CO_3 or CH_3COOK. However, the hydrogen yield and carbon conversion decreased as the amount of KCl was increased due to inhibition of KCl on gasification. The maximum carbon conversion efficiency (88.0%) was obtained at 700 ℃ corresponding to hydrogen yield of 73.0 vol.% when K_2CO_3 of 20 wt.% K loading was used. In particular, discrepant catalytic performance was observed between K_2CO_3 and CH_3COOK at different temperatures and the corresponding mechanism was also discussed.