Chemical Looping for Combustion of Solid Biomass: A Review

Chemical looping combustion of solid biomass has the unique potential to generate energy with negative carbon emissions, while entailing an energy penalty compared to traditional combustion that is lower than that of the competing carbon capture technologies. In spite of these attractive features, research is still needed to bring the technology to a fully commercial level. The reason relies on a number of technological challenges mostly related to the oxygen carrier performance, its possible detrimental interaction with the biomass ash components, and the efficiency of the gas-solid contact with the biomass volatiles. This review is focused on these specific challenges which are particularly relevant when firing biomass rather than coal in a solid-based chemical looping combustion process. Special attention will be given to the most recent findings published on these aspects. Related performance evaluation by modeling, system integration, and techno-economic analysis will also be briefly reviewed.