Water Effect on Acid-Gas Capture Using Choline Lactate: A DFT Insight beyond Molecule-Molecule Pair Simulations

Design of quaternary ammonium type-ionic liquids as desiccants for an air-conditioning system

The liquid desiccant air-conditioning system allows reducing energy consumption compared to the conventional compressor-type air conditioners. In order to develop desiccant materials for air conditioners, we have investigated the dehumidification capability of quaternary ammonium Ionic Liquids (ILs) and the equilibrium water vapor pressure of aqueous solutions of these ammonium salts. Among the seven tested types of ILs, 2-hydroxy-N ,N ,N -trimethylethan-1-aminium dimethylphosphate ([Ch][DMPO4]) displayed the best dehumidification capability and the lowest equilibrium water vapor pressure. Furthermore, the 80% aqueous solution of [Ch][DMPO4] exhibited a less corrosive effect on four types of metals, i.e., steel (hot dip zinc-aluminum alloy plated steel), copper (C1100P), aluminum (A5052), and stainless steel (SUS: SUS304). It should be noted that this [Ch][DMPO4] is not only non-toxic but also exhibits a stable nature; the aqueous solution produced no odor after storing for over 1 year under ambient conditions.

Permeabilities of CO2, H2S and CH4 through Choline-Based Ionic Liquids: Atomistic-Scale Simulations

Molecular dynamics simulations are used to study the transport of CO2, H2S and CH4 molecules across environmentally friendly choline-benzoate and choline-lactate ionic liquids (ILs). The permeability coefficients of the considered molecules are calculated using the free energy and diffusion rate profiles. Both systems show the largest resistance to CH4, whereas more than 5 orders of magnitude larger permeability coefficients are obtained for the other two gas molecules. The CO2/CH4 and H2S/CH4 selectivity was estimated to be more than 104 and 105, respectively. These results indicate the great potential of the considered ILs for greenhouse gas control.

Simultaneous CO2 and SO2 capture by using ionic liquids: a theoretical approach

Density functional theory (DFT) methods were used to analyze the mechanism of interaction between acidic gases and ionic liquids based on the 1-ethyl-3-methylimidazolium cation coupled with five different anions.