Carbon dioxide capture via aqueous N-methyldiethanolamine (MDEA)-1-butyl-3-methylimidazolium acetate ([bmim][Ac]) hybrid solvent

In this study, aqueous hybrid solvents from a mixture of aqueous N-methyldiethanolamine (MDEA) and 1-butyl-3-methylimidazolium acetate, [bmim][Ac] as ionic liquids (ILs) were formulated at different mass ratio. In each aqueous hybrid solvents, the concentrations of MDEA were kept constant at 30 wt%. In the hybrid solvents, the solubility of CO₂ was investigated at [bmim][Ac] concentration of 10 wt% and 20 wt%, respectively and results were compared with pure aqueous MDEA solvent. It was observed that the solubility of CO₂ is significantly improved in the hybrid solvent as compared to the solubility of CO₂ in pure aqueous MDEA solvent. However, increasing the concentration of [bmim][Ac] from 10 wt% to 20 wt% has a negative effect on the solubility of CO₂ due to viscosity effect. It was also observed that hybrid solvents with 10 wt% [bmim][Ac] has better CO₂ loading capacity. Increasing pressure from 10 bar to 20 bar has demonstrated an increase in CO₂ absorption capacity as well as CO₂ absorption rate. Hybrid solvents prepared from amine and imidazolium ILs will be a promising solvent in the capturing of CO₂.