Mass Transfer Characteristics of CO2 and Blended Aqueous Solutions of [C2OHmim][Lys]/MDEA in a Microchannel

Inthis paper, the two-phase flow and mass transfer process ofCO(2) and [C(2)OHmim]-[Lys]/MDEA mixed aqueous solutionin a T-shaped microchannel were investigated systematically. By usinga high-speed camera connected to a computer, the two-phase flow patternswere recorded online, including the Taylor flow and a small amountof Taylor-bubbly flow. And the effects of ionic liquid concentrationand two-phase flow ratio (Q (G)/Q (L)) on bubble length, specific surface area, gas holdup,and mass transfer coefficient were studied experimentally. The resultsindicate that the blended solution of [C(2)OHmim]-[Lys]/MDEAcould significantly enhance two-phase mass transfer compared to single N-methyldiethanolamine aqueous solution. The reaction mechanismbetween CO2 and ionic liquid/amine mixed aqueous solutionwas also analyzed. On the basis of experimental data, some new correlationsfor predicting the bubble initial length and the volumetric mass transfercoefficient were proposed, which matched well with the experimentaldata. This work is helpful to provide new ideas for the design ofCO(2) absorbents and further improve the data of gas-liquidmass transfer in microchannels.

Automated summary

This paper systematically investigates the two-phase flow and mass transfer process of CO2 and [C2OHmim]-[Lys]/MDEA mixed aqueous solution in a T-shaped microchannel. The effects of ionic liquid concentration and two-phase flow ratio on bubble length, specific surface area, gas holdup, and mass transfer coefficient are experimentally studied. The results show that the mixed solution of [C2OHmim]-[Lys]/MDEA significantly enhances two-phase mass transfer compared to a single N-methyldiethanolamine aqueous solution. New correlations for predicting the bubble initial length and the volumetric mass transfer coefficient are proposed based on the experimental data.