Improving hydrogen-rich gas production from biomass catalytic steam gasification over metal-doping porous biochar.

Biomass to green H is a new route to produce sustainable energy. This study aimed to boost H-enriched gas production via gasification-catalytic steam reforming (GCSR) process of wheat straw (WS) over Ni, Fe, or Zn-doped carbon materials (MDCMs). Initially, steam injection rate (1 g/min) and residence time (15 min) was optimized based on the tradeoff between energy consumption and H-rich gas generation. The largest gas yield (90.77 mmol/g) and the lowest H production efficiency (ƞ: 7.89 g CO/g H) were observed for WS-derived biochar. Clearly, it was found MDCMs were favorable for reducing CO production due to the strengthened CO reforming reactions catalyzed by metal active sites. A higher ƞ (6.72 g CO/g H) was achieved for Ni-doping biochar (Ni/C). Importantly, Ni/C showed the ultrahigh carbon conversion efficiency (99.47%) and great tar elimination performance. Overall, GCSR process over MDCMs is a newly promising way to valorize biomass into H-rich gas.