MSWI Fly Ash Mineralizes CO ₂ for MEA‐Rich Solution Regeneration: Performance and Mechanism

ABSTRACT An integrated CO 2 absorption and mineralization process using monoethanolamine (MEA) as an absorbent and fly ash from municipal solid waste incineration (MSWI) as a mineralizer was studied. The effects of temperature, stirring speed, reaction time, and solid–liquid ratio on the CO 2 carbonation reaction were investigated. At the optimal conditions the carbon sequestration efficiency reached 25.2%. Analysis revealed significant pore structure changes and surface carbon enrichment on the fly ash post‐carbonation, indicative of a composite coating layer predominantly composed of calcite (CaCO 3 ) with minor magnesium‐carbonate phases. CO 2 in an MEA‐rich solution was permanently sequestrated in the form of CaCO 3 and MgCO 3 . The MEA solution maintained high CO 2 separation efficiency and loading capacity over four absorption–regeneration cycles, demonstrating potential low‐energy regeneration. The mechanism of CO 2 mineralization by MSWI fly ash was also explored.