A green approach to CO2 capture using fly ash-based catalysts: Performance and mechanistic insights

作者：Rui Zhang, Liangfu Zhou, Ting Li, Yingjie Niu, Haonan Liu, Ruqi Xiao, Chao’en Li, Francesco Barzagli · 发表于：Fuel · 年份：2025 · DOI：10.1016/j.fuel.2025.135098 · 被引用次数：23 · 研究领域：Carbon Dioxide Capture Technologies、Chemical Looping and Thermochemical Processes、Membrane Separation and Gas Transport

• Fly ash functionalized with Fe 2 O 3 and Al 2 O 3 to catalyze CCUS desorption process. • Functionalized fly ash reduced energy consumption by 43.6% in desorption. • Machine learning analyzed key catalyst features and their SHAP values. • Experiments confirmed the catalyst features highlighted by machine learning. • Acid and basic sites on functionalized fly ash synergistically enhance CO 2 release. Fly ash (FA), an abundant industrial by-product, has emerged as a promising catalyst for regenerating liquid sorbents used in CO 2 capture, significantly reducing the overall energy consumption of the process. Considering that the primary metal oxides in FA − Fe 2 O 3 and Al 2 O 3 − provide Brønsted and Lewis acid sites critical for enhancing CO 2 release, this study explores the development of modified catalysts by loading additional amounts of these metal oxides onto FA (resulting in Fe 2 O 3 -FA and Al 2 O 3 -FA), aiming to further improve FA-catalyzed CO 2 desorption. The performance of these catalysts was examined in desorption of a CO 2 -loaded MEA solution, focusing on key metrics such as CO 2 desorption rate, cyclic capacity and heat duty. Our findings indicate that modifying FA with metal oxides increases its surface acidity (both Brønsted and Lewis) and optimizes acid/alkali strength. Among the catalysts tested, Al 2 O 3 -FA exhibited superior performance, achieving a higher CO 2 desorption rate, greater cyclic capacity, and lower heat duty compared to Fe 2 O 3 -FA, unm...