Steam co-gasification of Japanese cedarwood and its commercial biochar for hydrogen-rich gas production

Abstract

In this study, steam gasification and co-gasification of Japanese cedarwood and its commercial biochar were performed in a lab-scale fixed-bed reactor to investigate the feasibility for producing H2-rich syngas. Ultimate analysis, proximate analysis, Brunauer-Emmett-Teller (BET) surface area analysis, and scanning electron microscopy (SEM) were conducted to understand the changes caused by the carbonization process. The effects of gasification temperature and steam flow rate on gas production yield from the steam gasification of the individual samples were investigated at first, which showed larger gas production yield and less tar yield for the steam gasification of the commercial biochar than that of raw cedarwood, indicating that the commercial biochar obtained from the carbonization process was more beneficial for the gasification. The co-gasification of raw Japanese cedarwood and its commercial biochar with different mixing ratios was conducted at different reaction temperatures. The synergistic effect was obviously observed. Especially, the commercial biochar with the highly porous structure and high content of alkali and alkaline earth metal (AAEM) species might provide the catalytic effect on cracking and reforming of tar derived from the raw cedarwood, resulting in a larger H2 yield. However, the catalytic effect and gasification reactivity of biochar would decrease by increasing the amount of raw-cedarwood in the blends due to the coke deposition on the surface of biochar.