Gasification of wheat straw and kenaf lignocellulosic biomass by continuous aqueous-phase reforming process

Among the various processes for the conversion of biomass into hydrogen-rich gas mixture, aqueous-phase reforming (APR) process was found to be an environmentally benign and efficient method. In the present study, wheat straw, sorghum and kenaf biomass materials were converted into water soluble products by catalytical thermal treatment in subcritical water conditions and then subjected to continuous-flow APR for converting the solubilized carbohydrates and others into hydrogen rich gas mixture. The experiments in these system were designed to examine effect of flow rate of biomass hydrolysate into system, gasification temperature, types of biomass and catalysts for active conversions and concentration of biomass feed. The lower flow rates were observed to be better since biomass hydrolysate and catalyst contact time was increased. Gasification at higher temperatures gave better gas yield and hydrogen selectivity. The results showed that wheat straw biomass produced higher hydrogen yield than sorghum and kenaf. The raney nickel catalyst exhibited better activity compared to Pt/C catalyst for hydrogen production in continuous-flow APR system.