CO2 Absorption by Aqueous NaOH Solution in Packed Column: Mass Transfer Coefficient and Absorption Rate

Gas absorption process with chemical reaction by liquid solvents is widely used in the treatment of acid gases and gas purification. In this study, CO2 chemically absorption experiments by aqueous solution of sodium hydroxide (NaOH) have been done in a packed column with Raschig Ring packings. Results are used for determination of CO2 absorption rate and volumetric overall mass transfer coefficient (KGa). Generally, the volumetric overall mass transfer coefficient (KGa) for CO2-NaOH system is function of the process main operating parameters such as liquid volumetric flux, input gas phase mole fraction of CO2. Also, these experiments indicated that the overall mass transfer coefficient is enhanced by doubling of liquid volumetric flux and solvent concentration in average of 90% and 70%, respectively. Although, CO2 absorption rate is raised by increasing of liquid flow rate and solvent concentration (doubling of each of them), up to 67% and 65, respectively.