Kinetic performance of ionic liquid – diethanolamine system for CO2 absorption

Ionic liquid 1-Butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([bmim][Tf2N]) and diethanolamine (DEA) blend in hexanol was examined experimentally to provide a dual solvent with high absorption capacity and low regeneration energy for post combustion CO2 absorption. For this purpose, kinetic parameters of the system with respect to termolecular reaction mechanism were determined by stopped-flow experiments. Activation energy of the reaction between the solvent and CO2 was found to be 58.89 kJ/mol. In addition, experiments were carried out in a gas-liquid reactor and the loading capacity and the initial absorption rate of 10 wt % [bmim][Tf2N]-15 wt % DEA system were found to be 0.43:1 mol ratio of CO2: DEA and 1.66 × 10−5 kmol/m2s, respectively. Cyclic absorption-desorption behavior of the solvent and its desorption achievement were also investigated briefly.