Amine aerosol emission during the CO 2 capture process is a critical issue leading to solvent loss and environmental risks. This work aims to elucidate its formation mech anism and the influence of key operational parameters. The emission characteristics (mass concentration and size distribution) of amine aerosols were systematically investigated on a 20 m3/h pilot-scale chemical absorption platform using monoethanolamine (MEA) as the solvent. The effects of five key parameters were examined: condensation nuclei concentration (from none to 1.03×106 cm-3), inlet CO2 concentration (0 % to 15 % by volume), flue gas temperature (40 to 70 ℃), lean liquid temperature (35 to 55 ℃), and lean CO 2 loading (0.02 to 0.48 mol CO 2/mol MEA). An Electrical Low -Pressure Impactor (ELPI +) was used for real -time aerosol measurement. The results demonstrate that the presence of condensation nuclei is a prerequisite for significant aerosol formation, with heterogeneous condensation on nuclei surfaces being the dominant mechanism, capable of increasing the aerosol mass concentration by an order of magnitude. The aerosol emission peaked at an inlet CO 2 concentration of approximately 10 %. Increases in both flue gas temperature and lean liquid temperature were found to exacerbate aerosol emissions due to enhanced amine volatility and reaction kinetics. Lean CO 2 loading was identified as the most influential parameter. Increasing the loading from 0.02 to 0.48 mol CO2/mol MEA resulted in a drastic reduction of aerosol mass concentration by 94.6 %, 2 http ://rlfd.cbpt.cnki.net which is primarily attributed to the decreased concentration and volatility of free MEA in the liquid phase. This study elucidates the growth mechanism of amine aerosols dominated by heterogeneous reactions and interfacial chemistry. It clearly indicates that effective emission control can be achieved through a dual strategy: removing condensation nuclei from the inlet flue gas at the source and optimizing operational parameters, notably operating at a moderately high lean CO 2 loading. The findings provide crucial experimental data and theoretical support for predicting, mitigating, and optimizing amine aerosol emissions in industrial amine-based carbon capture systems.