Advances in biomass chemical looping combustion technology: Process control and comprehensive evaluation

Biomass chemical looping combustion (bio-CLC) technology represents a highly cost-effective method for carbon capture, offering significant prospects for practical applications. This paper reviews the critical process control factors of bio-CLC, including the type of biomass feedstock, operating conditions such as temperature and pressure, circulation rate, and the oxygen carrier-to-fuel ratio. Among oxygen carriers, mineral-based options like Fe-, Cu-, and Mn-based carriers, are identified as optimal for biomass processing. Ilmenite is particularly effective among these options. Biomass ash plays a pivotal role in the reaction process by interacting with the oxygen carrier. Sodium (Na) typically inhibits the reactivity of iron-based carriers, while potassium (K) is not significant. The alkaline ash content emitted by the fuel reactor (FR) is over seven times greater than that from the air reactor (AR), however ilmenite can absorb more than 95 % of this alkali. Techno-economic analyses reveal that biomass CLC for power generation can achieve CO₂ capture efficiencies exceeding 90 %, with net electrical efficiencies over 40 %. Despite an approximate 10 % increase in costs, biomass CLC remains one of the most economically viable carbon capture technologies. Life Cycle Assessment (LCA) further confirms that bio-CLC offers substantial environmental benefits, bio-CLC can reduce GWP by over 90 % in some cases, which significantly influenced by OC processing. Current research remains insufficient in integrating pretreatment processes. Ilmenite, manganese ores, and industrial metallic wastes are the most practical oxygen carriers for industrial use. To move forward, pilot-scale experiments and systematic scaling tests are urgently needed.