Review of Biomass Chemical Looping Gasification in China

Biomass chemical looping gasification (BCLG) is a novel and promising technology for syngas production, in which lattice oxygen in oxygen carriers (OCs) reacts with biomass. OCs can continuously supply oxygen for biomass gasification using a redox cycle between different reactors, and the reduced OC can serve as a good catalyst for biomass tar and char cracking, improving the gasification efficiency. The notable advantages of BCLG have attracted attention around the world, particularly in China. Chinese researchers have become the major drivers of the development of BCLG technologies. The experience gained from the experimental tests of BCLG in China is valuable for the further development of BCLG. In this review, we mainly focus on the biomass feedstock, the OC, the tar yield, the reactor, and the results of the BCLG tests in Chinese studies. On the basis of those findings, we summarize the criteria for biomass and the OCs in BCLG, and potential directions for reactor development are briefly discussed. In general, the mechanism of BCLG has been investigated in many studies, and the effects of the operating conditions are relatively well-understood. However, there are still few reports on BCLG units that have potential for industrial application. The controllable composition of syngas is worthy of further investigation, and this is required for downstream utilization. Additionally, as a result of the low pollutant emission, chemical looping gasification of solid wastes might be available in the future.