Chemical Engineering & Technology, Vol.33, No.1, 74-81, 2010
Carbon Dioxide Desorption from Saturated Organic Solvents
Carbon dioxide removal from various gaseous streams and its subsequent recovery are of considerable industrial importance. The absorption technologies represent the most important operation to separate CO2. In this work, the mass transfer rates during CO2 absorption and desorption from propylene carbonate dimethyl ether of polyethylene glycol, and N-methyl-2-pyrrolidone solutions were measured over the temperature range of 293.15-323.15 K in a baffled agitated reactor with a flat gas-liquid interface operated in a batchwise manner. Two distinct mechanisms of desorption were observed: bubbling and diffusive desorption. The volumetric gas-liquid mass transfer coefficients for the bubbling desorption were determined from the measured overall and diffusive desorption rates, and were correlated by the semi-empirical equation. The proposed correlation is a power relationship of supersaturation, Reynolds and Weber numbers, and was found to quantitatively explain the observed phenomena with satisfactory agreement.