[Objective

]

The amine aerosols formed during the amine-based CO

2

capture process are a critical issue leading to solvent loss and environmental risks. This work aims to elucidate the amine aerosols' formation mechanism and the influence of key operational parameters. [Methods

]

The formation mechanism and emission characteristics(mass concentration and size distribution) of amine aerosols were systematically investigated on a 20 m

3

/h pilot-scale chemical absorption platform using monoethanolamine(MEA) as the solvent. The effects of five key parameters were examined

such as number concentration of condensation nuclei(from none to 1.03×10

6

cm

–3

)

CO

2

volume fraction in inlet flue gas(0 to 15%)

flue gas t

emperature(40～70 ℃)

lean liquid temperature(35～55 ℃)

and CO

2

loading in lean liquid(0.02 to 0.48 mol CO

2

/mol MEA). An electrical lowpressure impactor(ELPI

+

) was used for real-time aerosol measurement. [Results

]

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 aerosols' emission peaked at an inlet CO

2

volume fraction 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. CO

2

loading in lean liquid was identified as the most influential parameter. Increasing the CO

2

loading in lean liquid from 0.02 mol CO

2

/mol MEA to 0.48 mol CO

2

/mol MEA resulted in a drastic 94.6% reduction in aerosols' emission mass concentration

which is primarily attributed to the decreased concentration and volatility of free MEA in the liquid phase. [Conclusion

]

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 CO

2

loading in lean liquid. The findings provide crucial experimental data and theoretical support for predicting

mitigating

and optimizing amine aerosol emissions in industrial amine-based carbon capture systems.