Carbon Dioxide Absorption by Amines: System Performance Predictions and Regeneration of Exhausted Amine Solution

Carbon dioxide (CO2) absorption by alkanolamines in a packed column was investigated experimentally and theoretically. The alkanolamines used in the present study were the primary monoethanolamine (MEA) and tertiary N-methyldiethanolamine (MDEA), two popular amines widely used in the chemical and petrochemical industries for gas purification. The CO2 absorption characteristics by these two alkamolamines were examined experimentally under various operating conditions. A theoretical model was developed for describing the CO2 absorption behavior. Test data indicated that the predictions using the proposed model and the observed CO2 absorption breakthrough data agree very well. Preliminary studies of regeneration of exhausted alkanolamine solution were also conducted to determine the optimum regeneration conditions. The test results revealed that the tertiary amine is easier to regenerate with less loss of absorption capacity than the primary one.