Study on energy consumption optimization of membrane-based carbon capture process for coal-fired power plant flue gas and its coupling mechanism with Carbon cycle in surrounding terrestrial ecosystems

Abstract To address the core contradiction between “carbon emission reduction” and “energy efficiency loss” in the coal-fired power industry, while enhancing the synergistic carbon sink benefits of the entire carbon capture, utilization, and storage (CCUS) chain, this study focuses on the energy consumption optimization of the membrane-based carbon capture process for coal-fired power plant flue gas and explores its coupling mechanism with the carbon cycle in surrounding terrestrial ecosystems. By constructing a mass transfer-energy consumption coupling model for membrane modules and optimizing operating parameters as well as membrane material performance, the unit energy consumption of the membrane-based carbon capture system is reduced from the industry average of 3.2 GJ/t CO 2 to 2.1 GJ/t CO 2 , with the CO 2 capture rate stably maintained above 90%. Based on the improved CENTURY model, this study quantitatively analyzes the impact of geological storage/vegetation carbon sequestration of captured CO 2 on the carbon cycle in surrounding forest and grassland ecosystems, and finds that the optimized carbon capture system can increase the annual carbon sink increment of terrestrial ecosystems within a 5 km radius by 18.3%. Finally, a coupling evaluation model of “energy consumption optimization - carbon flow regulation - ecological carbon sink” is established, providing theoretical support and technical pathways for low-cost carbon emission reduction in the coal-fired power industry and the synergistic improvement of regional ecological carbon cycles.