Desorption of carbon dioxide from aqueous MDEA solution in a microchannel reactor

Abstract

CO2 desorption from N-methyldiethanolamine (MDEA) rich solutions was investigated experimentally in a highly efficient microchannel reactor. The effects of various parameters including MDEA concentration, desorption temperature, solution flow rate and CO2 loading on the CO2 desorption rate were studied. It was found that the CO2 desorption rate was most sensitive to the desorption temperature. The CO2 desorption almost reached equilibrium when the solution residence time was about 7s, indicating the advantages of using microchannel reactors for rapid CO2 desorption. The value of kLa was in the range of 0.36–2.68s−1 in the experiments, which is comparable to that of absorption in microchannels and much larger than in conventional equipment. For the design of micro-desorbers, empirical correlations were proposed to predict the mass transfer coefficient with good prediction performance.