Experimental Study of Carbon Dioxide Solubility in Aqueous N-Methyldiethanolamine Solution with 1-Butylpyridinium Tetrafluoroborate Ionic Liquid

Abstract

New experimental data for CO2 solubility in the aqueous solutions of N-methyldiethanolamine (MDEA) and 1-butylpyridinium tetrafluoroborate ([Bpy]­[BF4]) ionic liquid (IL) are reported. The experiments were conducted in a static high pressure equilibrium cell. Solubility measurement of CO2 was performed in various solution compositions of IL and MDEA in a wide temperature range of 298.15–343.15 K and pressures up to 4 MPa. The experimental results revealed that, by increasing the weight percent of IL, the absorption capacity of aqueous mixtures diminishes. It was also observed that the main capacity of CO2 loading in the absorbent solutions belonged to MDEA through chemical absorption, whereas its concentration was more effective than IL in gas solubility. The experimental results are correlated using a semiempirical model with good accuracy.

Green solvents for CO2 capture

“…[31,32], evaluated the use of water as a co-solvent. [14,26,27,33,34] As stated by the authors, the IL-amine hybrid solvents have shown to be, through the manipulation of the IL concentration, an energy-saving system for CO 2 capture with reduced heat of absorption and manageable diffusivities and kinetics. [14] Gómez-Coma et al [13] aiming at enhancing the CO 2 chemisorption, through the optimization of acetate-based ILs, proposed the use of aqueous solutions of 1-ethyl-3methylimidazolium acetate in nondispersive absorption in a polyvinylidene fluoride hollow fiber membrane contactor.…”

“…[9] At present, the research on ILs mixed solvents for CO 2 capture focus mainly on ILwater solutions, IL-alkanolamine blends, IL-organic solvents and IL-IL mixtures. [13,14,[25][26][27] Although not a trivial task, due to the strong dependence on the nature of the constituents ions/compounds, several authors evaluated mixtures of ILs as a mechanism to increase the sorption capacity by manipulating specific interactions, excess volume and viscosity. As reported by Moya et al.…”