Intensification for CO 2  alkaline absorption in H 2 -rich stream purification with T-type microchanne

The limited conversion of CO2 hydrogenation would generate a large amount of H2-rich stream, and microchannel presents considerable potential for the impurities removal to these H2-rich stream purification. A three-dimensional absorption model is established and supposed to demonstrate the characteristics of chemical absorption and mass transfer in T-type microchannel with concave or convex structure. The Taylor bubble flow in microchannel would enhance the interface mass transfer rate even in the length of 5 mm within second. The reduction of diameter and gas-liquid ratio (RGL) will enhance the interface mass transfer efficiency to significantly improve H2-rich purification. Both concave and convex structure would change the length and residence time for the single bubble and cause violent fluctuation for the gas-liquid flow, resulting in higher CO₂ absorption rate of 53% and 72.5% than the 51.48% for cylindrical microchannel at 5 mm length at RGL = 8:3. Specially, the CO₂ absorption rate for convex microchannel can reaches 88.7% within 5 mm length at RGL = 1, while it is 87.42 % within 15 mm length at RGL = 8:3 to realize the H2 purity of 99.41%.