Chemical looping gasification and sorption enhanced gasification of biomass: A perspective

Chemical looping gasification (CLG) and sorption enhanced gasification (SEG) of biomass are promising technologies to improve the energy efficiency and simplify the processes for producing renewable hydrogen, synthetic fuels, and chemicals. In terms of process intensification, CLG achieves inherent air separation through the use of oxygen carriers, eliminating the need of air separation units. With inherent CO2 separation enabled by CO2 sorbents, SEG can directly generate hydrogen-rich syngas (> 70 vol.% H-2) without individual water-gas shift and CO2 separation units. The state-of-the-art of the reactors, functional materials, and modeling works for CLG and SEG is reviewed in this paper. The impact of essential process parameters, including temperature, solid circulation rate, and steam-to-biomass ratio, is summarized. The research needs and outlook of CLG and SEG are discussed. Combining the perspectives of both basic research and practical application, this paper is expected to serve as a valuable guide for academic research groups, industry stakeholders, and policy makers seeking to research, invest in, or evaluate biomass CLG and SEG.