Emission characteristics of ethanolamine and ammonia in CO2 capture process by chemical absorption based on ethanolamine solution

BACKGROUND The massive emission of greenhouse gases represented by CO 2 has led to many environmental and climate problems. Chemical absorption after combustion has become an effective method for CO 2 capture. Meanwhile, this method also leads to potential emission of pollutants, consisting mainly of ethanolamine (MEA) and ammonia (NH 3 ). However, few studies focus on the emission characteristics of pollutants in chemical absorption systems and the factors influencing the emissions. RESULTS In this experiment, MEA and NH 3 emissions during the CO 2 capture process by the chemical absorption method under different conditions, such as flue gas and absorbent solution temperature, liquid-to-gas ratio, CO 2 concentration in the flue gas, and absorbent CO 2 loading, were investigated. The results indicate that the MEA and NH 3 are released during the CO 2 capture process, and the amount of release varies with many parameters. Under typical conditions, the emissions of MEA and NH 3 were stabilized at 85.8 and 21.5 mg Nm −3 , respectively. The emissions of MEA and NH 3 increased steadily with the temperature of the flue gas and increasing absorbent solution. Higher liquid-to-gas ratio led to more MEA and NH 3 emissions, and higher absorbent CO 2 loading could inhibit the MEA and NH 3 emissions. Calculation of the maximum reduction rate also showed that CO 2 loading has the greatest impact on pollutant emissions, and optimizing it reduces pollutant emissions by at least 40%. CONCLUSION It was found that pollution emissions can be controlled by optimizing operating parameters, which can provide a reference for reducing pollutant emissions in the industry. © 2025 Society of Chemical Industry (SCI).