Effect of microwave pretreatment on catalytic gasification of spirit-based distillers' grains to hydrogen-rich syngas.

Steam gasification of spirit-based distillers' grains (SDGs) was performed in a fixed-bed reactor under different microwave pretreatment (MWP) approaches with or without addition of red mud (RM). The effects of MWP on the gasification rate, total gas yield, H/CO, and gasification mechanism of action were investigated. The results showed that RM could enhance the effect of MWP. The gasification rate, total gas yield and H/CO increased by 21.29%, 8.23% and 16.08%, respectively. In addition, RM and MWP had a synergistic effect on the catalytic gasification reaction. This was because MWP disrupted the complete ordered surface structure of the SDGs, allowing a large number of inherent alkali and alkaline earth metal ions to dissolve onto the surface and combine with the catalytically active material in RM to form a uniformly dispersed bimetallic catalyst. The catalytic mechanism consisted of an active-site catalytic mechanism and a bimetallic synergistic catalytic mechanism. Therefore, the combination of MWP and SDGs steam gasification is a promising, clean, efficient hydrogen-rich synthesis gas technology.