Carbon dioxide-cofeeding pyrolysis of pine sawdust over nickle-based catalyst for hydrogen production

This study aimed to determine the synergistic effects of CO2 on the catalytic pyrolysis of pine sawdust over a Ni-based catalyst (Ni/SiO2) to establish a sustainable platform for H-2 production. To elucidate the reaction mechanism, the CO2-cofeeding pyrolysis of pine sawdust was performed. The CO2-cofeeding pyrolysis of pine sawdust proved that the gas-phase reaction between CO2 and pyrolysates led to the increase in the amount of generated CO. The CO2 enhanced thermal cracking and dehydrogenation. These mechanistic features of CO2 were catalytically enhanced when Ni/SiO2 was employed as heterogeneous catalyst, which led to an increase in the amounts of generated H-2 and CO. Hence, the CO that was additionally generated during the gas-phase reaction of CO2 and pyrolysates could be further converted into H-2. In addition, CO2 could be looped in the CO2-cofeeding pyrolysis of pine sawdust. Furthermore, exploiting CO2 as raw material or reactive gas medium in the catalytic pyrolysis process also offered a strategic means for preventing coke formation.