Ultra-low carbon dioxide emissions for biomass gasification using air with nearly 100% CO2 capture and conversion

Abstract

Addressing the high CO 2 emissions from biomass gasification is crucial for enhancing the sustainability and environmental profile of this technology. This work proposes a novel approach by integrating the biomass gasification process with carbon capture and utilisation (IGCCU), to tackle the substantial challenge of traditional biomass gasification, which leads to high CO 2 emissions. Specifically, during the biomass gasification stage, this novel approach successfully captured 14.39 mmol g -1 lignin of CO 2 , based on benchmark conditions. The captured CO 2 is subsequently converted into CO during the hydrogenation stage, achieving a peak CO concentration of 1.58 %. The results reveal that maintaining a marble feeding mass of 6 g and setting the reaction temperatures for gasification, carbon capture, and hydrogenation at 500 C, 400 C, and 550 C, respectively, consistently ensures ultra-low CO 2 emissions throughout the entire process. "Ultra-low CO 2 emissions" specifically refers to the absence of CO 2 signals throughout the entirety of the IGCCU process, encompassing stages such as biomass gasification, CO 2 capture, and CO 2 conversion. Notably, CO 2 conversion and CO selectivity remain at a stable 100 % level over 8 cycles as only CO was generated during the hydrogenation stage, underscoring the excellent stability of this novel technology. Furthermore, the utilisation of low-cost sorbent material (waste marble powder) and the readily available biomass gasification agent (air) enhance the economic feasibility of this new technology while demonstrating robust resistance to carbon deposition.