Mass transfer and thermodynamic modeling of carbon dioxide absorption into MEA aqueous solution

In this research, thermodynamic and absorption rate of carbon dioxide in monoethanolamine (MEA) solution was investigated. A correlation based on both liquid and a gas phase variable for carbon dioxide absorption rate was presented using the π-Buckingham theorem. The correlation was constructed based on dimensionless numbers, including carbon dioxide loading, carbon dioxide partial pressure, film parameter and the ratio of liquid phase film thickness and gas phase film thickness. The film parameter is used to apply the effect of chemical reactions on absorption rate. A thermodynamic model based on the extended-UNIQUAC equations for the activity coefficients coupled with the Virial equation of state for representing the non-ideality of the vapor phase was used to predict the CO₂ solubility in the CO₂-MEA-H₂O system. The average absolute error of the results for the correlation was 6.4%, which indicates the accuracy of the proposed correlation.