Conductor‐like‐screening model for real solvents (COSMO‐RS) method was used to analyze the solute‐solvent interactions and to screen Henry's law constant of toluene over 272 ionic liquids (ILs), to select high‐capacity absorbents. Thermogravimetric experiments were carried out to evaluate the toluene absorption by selected ILs at different temperatures and atmospheric pressure. Experimental equilibrium data were found in good agreement with COSMO‐RS predictions. Complete desorption of toluene by N2 stripping was achieved, indicating an easy regeneration. The kinetic curves were described by a phenomenological diffusion model, obtaining effective diffusivities in reasonable concordance with those calculated by Wilke–Chang correlation. The separation process with selected ILs was modeled by Aspen Plus and a comparison with organic absorbents was carried out. Equilibrium‐ and rate‐based simulations were used to analyze the importance of thermodynamics and kinetics in toluene absorption by ILs. Current computational‐experimental research allowed selecting a set of suitable ILs for toluene absorption. © 2012 American Institute of Chemical Engineers AIChE J, 59: 1648–1656, 2013

No abstract

No abstract

No abstract

The interactions between ionic liquids (ILs) and acetone have been studied to obtain a further understanding of the behavior of their mixtures, which generally give place to an exothermic process, mutual miscibility, and negative deviation of Raoult's law. COSMO-RS was used as a suitable computational method to systematically analyze the excess enthalpy of IL-acetone systems (>300), in terms of the intermolecular interactions contributing to the mixture behavior. Spectroscopic and COSMO-RS results indicated that acetone, as a polar compound with strong hydrogen bond acceptor character, in most cases, establishes favorable hydrogen bonding with ILs. This interaction is strengthened by the presence of an acidic cation and an anion with dispersed charge and non-HB acceptor character in the IL. COSMO-RS predictions indicated that gas-liquid and vapor-liquid equilibrium data for IL-acetone systems can be finely tuned by the IL selection, that is, acting on the intermolecular interactions between the molecular and ionic species in the liquid phase. NMR measurements for IL-acetone mixtures at different concentrations were also carried out. Quantum-chemical calculations by using molecular clusters of acetone and IL species were finally performed. These results provided additional evidence of the main role played by hydrogen bonding in the behavior of systems containing ILs and HB acceptor compounds, such as acetone.