Utilizing steel slag in sorption-enhanced biomass gasification: A pathway to syngas production with integrated CO2 capture

Developing economical catalysts is of significant importance for the advancement of the sorption-enhanced gasification technology. In this study, through fixed-bed experiments and Aspen Plus simulations, the potential of steel slag as a catalyst in the biomass sorption-enhanced gasification process was comprehensively explored. The sorption-enhanced gasification experimental results indicated that steel slag could facilitate the sorption-enhanced gasification reaction, with the gas yield increasing from 250.3 ml/gbiomass in the absence of catalysts to 389.8 ml/gbiomass, representing an increment of 55.73 %. The typical components of steel slag, Fe2O3 and CaO, could enhance the yield of gas in the sorption-enhanced gasification, while SiO2 exhibited a relatively minor promoting effect. Furthermore, after five cycles of tests, the steel slag demonstrated a gas yield of 341.4 ml/gbiomass, exhibiting good cyclic stability. However, the low selectivity of gas products limited the application of steel slag in the sorption-enhanced gasification. Enhancing the specific surface area and oxygen reactivity of steel slag was potential directions for improving its sorption-catalytic properties. The Aspen results indicated that the introduction of steel slag led to a 41.64 % increase in the annual production income of methanol. This study provided valuable insights into the high-value utilization of steel slag.