Mass transfer characteristics of H2S absorption from gaseous mixture into methyldiethanolamine solution in a T-junction microchannel

In this work, the mass transfer characteristics of absorption of H2S (1200 ppmv) into 40 wt% methyldiethanolamine (MDEA) solution have been investigated experimentally in a horizontal cross-flow T-junction microchannel with a diameter of 1.00 mm. The interfacial area was determined by the absorption of CO2 into NaOH solution. It was found that the high removal efficiency of H2S (up to 99.5%) was achieved in the microchannel. Mass transfer resistance existed mainly on the gas side in this absorption process. It was shown that the gas side volumetric mass transfer coefficient and interfacial area were as high as 31,746 mol/(m3 s atm) and 11,100 m2/m3, respectively. In addition, a comparison of mass transfer performance among different gas–liquid contactors was performed. It was revealed that the T-junction microchannel in this study could provide at least one or two orders of magnitude higher gas side volumetric mass transfer coefficient than others. However, the intensification of mass transfer process was mainly ascribed to the enhancement of interfacial area rather than the gas side mass transfer coefficient. Empirical correlations based on the experimental data were developed to predict gas side mass transfer coefficient and interfacial area.