Functional Biochar Synergistic Solid/Liquid-Phase CO<sub>2</sub> Capture: A Review
Yu Zhang, Shizhang Wang, Dongdong Feng, Jianmin Gao, Linhan Dong, Yijun Zhao, Shaozeng Sun, Yudong Huang, Yukun Qin
Abstract
Nowadays, global warming is becoming more and more serious, while CO2 capture technologies have emerged endlessly, with methods of solid-phase CO2 capture for physical adsorption and liquid-phase CO2 capture for chemical absorption. Biochar has been widely used to achieve CO2 sequestration and emission reduction as a result of its wide range of precursor sources, strong adsorption, and rich surface functional groups. It reviews the existing post-combustion CO2 capture solutions, focusing on the analysis of CO2 capture technologies based on liquid-phase ammonia/monoethanolamine and solid-phase carbon-based materials. The former (liquid phase) is with limitation of capture efficiency as a result of strong volatility and thermal degradation, while the latter (solid phase) is accompanied by limited CO2/N2 selectivity. The realization of synergy between the two would “learn from each other’s strengths” to improve the CO2 adsorption ability. The review puts forward the concept of “biochar-functionalized cross-linking synergistic ammonia CO2 capture technology”, which not only broadens the idea of multi-level utilization of biochar, significantly improving the liquid-phase (ammonia) CO2 capture efficiency, but also has practical significance for the utilization of biomass waste and reduction of CO2 emissions.