Monoethanolamine and ionic liquid aqueous solutions as effective systems for CO₂ capture

Abstract

BACKGROUND: Ionic liquids are regarded as future effective absorbents of CO 2 , however high viscosity of this medium limits its use in industry. To resolve the problem a mixture of alkanolamine, ionic liquids and water was proposed as a CO 2 absorbent and the influence of solution composition on the volume of CO 2 absorbed was determined. RESULTS:In most binary mixtures of ionic liquids and water tasted the presence of water does not affect the overall capacity of absorption mixture except for the 1-butyl-3-methylimidazolium acetate where each mol of water added to the mixture reduces the volume of CO 2 that could be absorbed by more than one mole. The capture of CO 2 using three-component systems of water/ionic liquid/monoethanolamine (MEA) was systematically investigated with two selected ionic liquids: 1-butyl-3-methylimidazolium acetate and 1-ethyl-3-methylimidazolium octylsulfate. It was shown that the volume of CO 2 absorbed is linearly dependent on the mass fraction of components for 1-ethyl-3-methylimidazolium octylsulfate over the entire experimental domain whereas in 1-butyl-3-methylimidazolium acetate the interaction between ionic liquid and water substantially decreases the volume of CO 2 absorbed. CONCLUSIONS: The best results for CO 2 absorption were obtained using the three component system 1-butyl-3methylimidazolium acetate/monoethanolamine/water. Optimization of the composition of an IL-MEA-water mixture allows tuning of the properties of the medium. The CO 2 absorption capacity of the mixture is mainly a function of MEA concentration and, to a lesser degree, of the concentration of IL possessing chemisorption abilities. The presence of water decreases the viscosity of the mixture and therefore facilitates the application of IL-based media in industrial applications.

Ionic liquids tailored amine aqueous solution for pre-combustion CO2 capture: Role of imidazolium-based ionic liquids

“…It was observed that DEA-carbamate is easy regeneration because of low regenerating temperature ($55°C) and volume [26,27] [15]. In addition, ILs + amine + H 2 O for CO 2 capture with low energy consumption has been reported on many literatures [13,14,16,22,25]. Although water effects the CO 2 solubility, it will facilitate the industrial application of the mixture because of decreasing viscosity [22].…”

“…In addition, ILs + amine + H 2 O for CO 2 capture with low energy consumption has been reported on many literatures [13,14,16,22,25]. Although water effects the CO 2 solubility, it will facilitate the industrial application of the mixture because of decreasing viscosity [22]. To capture CO 2 4 ] can save about 15% sensible and latent heat compared to the conventional MEA process [13].…”

Tailoring amine functionalized hybrid ceramics to control CO2 adsorption

“…As an example, 2.2 mmol g -1 were for found at atmospheric pressure and 30 °C for the ionic liquid 3-aminoethyl-2-methyl-1-methylimidazolium dicyanamide and the value decreased to 1.5 mmol g -1 at 50 °C [56]. Mixtures of ionic liquids with monoethanolamine resulted in CO 2 sorption capacities of about 2.5 to 3.5 mmol g -1 [57]. Since many amine modified ionic liquids exhibit increased viscosities they are often applied on a supporting material to overcome these problems [58].…”

Sustainable improvement of the tetrabromoethylcyclohexane synthesis using Amino ILs as Catalysts in Water. A facile and environmentally-friendly procedure

“…ILs have been used to provide environmentally‐friendly approaches for specific processes (i.e. CO 2 capture, transesterification processes and the removal of anionic azo‐dyes).…”