Hydrodynamic and mass transfer analysis of CO2 absorption into caustic solution at different normality

Enhancement factor for the process of CO2 absorption into caustic solution at three different concentrations of 0.1, 0.3 and 0.5 normal were measured and correlated against liquid rates and pressure drop in the column. The column employed in the experiments was a glassy Pyrex column with a height of 1.9 meter and an inner diameter of 0.08 meter which was packed to the height of 1.1meter by 8 mm glassy rashig rings. The gas and liquid arrangements to the column was counter-current and CO2 from air was being absorbed by the caustic solution. It was found that by increasing the caustic normality it was possible to enhance the absorption process but increasing of the liquid rates and pressure drop gradients in the column on the other hand had a diverse effect on the enhancement factor at a constant caustic normality. This observation dictated that this process was reaction control and sensitive to the residence time of the liquid phase in the column.

Keywords:

Absorption , Carbon dioxide , enhancement factor , Mass transfer , packed bed