Solubility of N2O, equilibrium solubility, mass transfer study and modeling of CO2 absorption into aqueous monoethanolamine (MEA)/1-dimethylamino-2-propanol (1DMA2P) solution for post-combustion CO2 capture

Abstract

In order to establish an integrative mass transfer coefficient (KGaV) model for CO2 absorption into blended monoethanolamine (MEA)/1-dimethylamino-2-propanol (1DMA2P) solution in packed column, the models of CO2 Henry’s law constants (HeCO₂-MEA/1DMA2P) and the equilibrium CO2 solubility (αeq) were constructed. The experimental produced data can be reasonably analyzed. In this work, the Arrhenius equation was employed to fit the values of HeCO₂-MEA/1DMA2P at different temperature with AARD of 4.06%; the Kent-Eisenberg prediction model and empirical polynomial prediction model were used to predict the data of αeq under different CO2 partial pressures and temperatures with AARDs of 2.64% and 0.83%, respectively; the empirical KGaV model proposed by Li, the empirical KGaV model proposed by Aroonwilas and new KGaV model were used to correlate the average values of KGaV with AARDs of 14.36%, 12.44% and 9.03%, respectively; the model for outlet CO2 concentration (yCO₂,out) in packed column was developed with AARD of 15.97%. Moreover, the heat of CO2 absorption in 6 kmol/m3 MEA/1DMA2P solution was estimated by Gibbs-Helmholtz equation which gave a value of −39.8 kJ/mol. The results show that the blended MEA/1DMA2P solution has advantages that make it a potential absorbent for CO2 capture.