Thermodynamic Performance Analysis of Membrane Absorption CO₂ Capture System for Coal-fired Power Plants

To achieve energy conservation and consumption reduction in CO₂ capture systems, membrane absorption technology was employed to treat desulfurized flue gas in coal-fired power plant, enabling the simultaneous capture of CO₂, recovery of flue gas waste heat, and reduction of absorbent losses. Based on the multi-porous membrane heat and mass transfer model, a simulation model coupling the membrane absorption CO₂ capture system with the thermal system of the coal-fired power plant was developed. The CO₂ capture performance and its main influencing factors were analyzed, and the potentials for energy and water savings were evaluated. The results indicate that, compared with a conventional column CO₂ capture system, the membrane absorption system reduces the regeneration energy consumption from 3.69 MJ/kg to 3.66 MJ/kg through waste heat recovery. Furthermore, by decoupling the CO₂ capture process from the flue gas flow, absorbent losses are minimized, achieving water savings of 130 800~143 290 kg/h and reducing the mass flow rate of the CO₂ absorbent monoethanolamine (MEA) solution by 702~901 kg/h.