Experimental study and modeling of CO2 absorption into diethanolamine solutions using stirrer bubble column

In this work, solubility and chemical absorption rate of carbon dioxide into aqueous solutions of diethanolamine (DEA) were studied in a stirred bubble column. In the experiments the effects of stirrer speed, amine concentration, CO2 partial pressure and CO2 loading on absorption rate and solubility were investigated. The experimental conditions are, amine concentration in range of 0.2-2.0 M, CO2 partial pressures in range of 2.4-3.6 kPa, stirrer speed in range of 0-600 rpm, CO2 loading in range of 0.1-0.7 mole of CO2 per mole of amine. The results showed that mass transfer flux and absorption percent of CO2 were varied in range of 34-59% and 0.35-4.32 kmol m−2 s−1, respectively. A thermodynamic model, based on Deshmukh and Mather model is proposed for the equilibrium solubility of CO2 in DEA solutions. It has been found that this model is able to estimate results which are close to the experimental data in terms of the total CO2 loadings of the solution. Predicted partial pressures of the CO2 over diethanolamine solution were also observed good deal with experimental data.