Comparison of mass transfer coefficients and desorption rates of CO2 absorption into aqueous MEAÂ +Â ionic liquids solution

- The KGav values of CO2 absorption into MEA + ionic liquids solution were determined.
- The influence factors of KGav value were discussed in a packed column.
- The catalytic action of ionic liquids on CO2 absorption was checked at first time.
- The effect of ionic liquids on CO2 desorption was studied in a packed column.

The mixed solvent of ionic liquids and ethanolamine (MEA) was used to absorb CO2 from mixed gases using a packed column. The density and viscosity of aqueous MEA + ionic liquids solution were determined at temperatures ranging from 303.15 to 323.15 K and ionic liquids mass concentrations from 20% to 30%, respectively. A comparison among the mass transfer of CO2 absorption into MEA + ionic liquids ([Bmim][Br], [Emim][Br]) and MEA was performed at 303.15-323.15 K. Meanwhile, the effects of the temperature, liquid flow rate and gas flow rate on the KGav value were discussed in this paper, respectively. At last, the desorption rates of rich solution were calculated by determining the volume of CO2 released from rich solution. The result showed that aqueous MEA + 20% [Emim][Br] solution had superior performance for CO2 capture. Moreover, as CO2 was absorbed by the mixture of MEA and ionic liquids, the catalytic action of ionic liquids was not obvious.

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