Mass Transfer Modeling of CO2 Absorption into Blended MDEA-MEA Solution

In this research, the thermodynamics and mass transfer of CO2 absorption has been studied in a mixture of MDEA-MEA amines. A relation is presented for mass transfer flux in the reactive-absorption process. For this purpose, the effective parameters on the mass transfer flux were investigated in both liquid and gas phases. Then, using dimensional analysis with the Pi-Buckingham theorem, the effective variables were extracted as the dimensionless parameters. Also, the absorption process with MEA-MDEA is modeled according to four laws of chemical equilibrium, phase equilibrium, mass, and charge balance (considering the appropriate thermodynamic model for solvent). The experimental data of the previous research was used to calculate the dimensionless parameters. The constants of the mass flux equation are calculated with the fitting method. Also, the effects of operating parameters such as CO2 partial pressure, temperature, and dimensionless parameters such as the film parameter, enhancement factor, and loading have been investigated. The results showed that by increasing the loading and film parameter, the mass flux decreased, and the mean absolute error obtained from the proposed relationship was about 4.3%, which indicates the high accuracy of the predicted equation.