Affiliation: | 1. State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
Contribution: Data curation (lead), Investigation (lead), Writing - original draft (lead);2. State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China |
Abstract: | The gas–liquid two-phase flow pattern, absorption rate and pressure drop of CO2 absorbed into the aqueous solution of the task-specific ionic liquids (1-aminopropyl-3-methylimidazole tetrafluoroborate Apmim]BF4] and 1-hydroxyethyl-3-methylimidazole tetrafluoroborate OHemim]BF4]) and halide-free ionic liquid 1-butyl-3-methylimidazolium methylsulfate Bmim]CH3SO4] were investigated in a microreactor. The absorption mechanism of the three ionic liquids was analyzed employing the 13C NMR spectroscopy. The Apmim]BF4] was found to have the best ability of CO2 capture compared with the other two ionic liquids, as chemical absorption occurred between Apmim]BF4] and CO2, while only physical absorption took place between OHemim]BF4]/Bmim]CH3SO4] and CO2. The sequence of CO2 absorption rate in three ionic liquids aqueous solutions is: Apmim]BF4] > Bmim]CH3SO4] > OHemim]BF4]. Furthermore, the effects of gas–liquid flow rate and ionic liquids concentration on CO2 absorption rate and pressure drop were studied, the pressure drop models based on various flow patterns were proposed. |