Experimental study of CO2 absorption and solvent regeneration using aqueous monoethanolamine blended with ammonium based ionic liquids

Abstract

The rapid increase of CO2 concentration in the atmosphere leads to global warming and other climatic changes in the environment. Carbon Capture, Utilization and Storage (CCUS) is a promising technique to mitigate the CO2 emissions in order to provide a cleaner environment. Solvent-Based Post-Combustion CO2Capture process is performed by chemical absorption using Monoethanolamine (MEA) as commercial solvent. This solvent demands higher energy consumption during regeneration. To overcome this, Ionic Liquids (ILs) have been recently used as alternative solvents for CO2 capture process, because of its attractive properties such as negligible vapor loss, high thermal and chemical stability. Thus, the selection of suitable solvent is important and this can be identified by solvent screening for efficient removal of CO2 by absorption process. newlineThe solvent screening was performed experimentally by investigating the various physical properties such as density, dynamic viscosity, surface tension of pure ILs, aqueous ILs and aqueous blends of MEA with ILs. The ionic liquids considered for present work are Tetra Butyl Ammonium Acetate [TBA][OAC], Tetra Butyl Ammonium Bromide [TBA][Br] and Tetra Butyl Ammonium Hydroxide [TBA][OH]. These properties were examined by varying temperature (283.4 to 333.4K) at an interval of 10K and concentration of aqueous ILs (10 - 50 wt%) at an interval of 10 wt%. The total concentration of aqueous MEA blended with ILs was kept as 30wt% and the blends were prepared accordingly (MEA concentration as 28wt%, 25wt%, 20wt% and IL concentration as 2wt%, 5wt%, 10wt%). The experimental results revealed that density, surface tension and dynamic viscosity of pure ILs decreased as the temperature increased. newline newline