Vapor-Liquid Equilibria of Water plus Alkylimidazolium-Based Ionic Liquids: Measurements and Perturbed-Chain Statistical Associating Fluid Theory Modeling

• Type: Article in International Scientific Journal
• Date: 2014

Authors

Helena Passos (Author) FEUP; Imran Khan (Author) Other; Fabrice Mutelet (Author) Other; Mariana B Oliveira (Author) Other; Pedro J Carvalho (Author) Other; Luis M N B F Santos (Author) FCUP; Christoph Held (Author) Other; Gabriele Sadowski (Author) Other; Mara G Freire (Author) Other; Joao A P Coutinho (Author) Other

Journal

Title: Industrial & Engineering Chemistry Research

Vol. 53

Pages: 3737-3748

ISSN: 0888-5885

Publisher: American Chemical Society

Indexing

ISI Web of Knowledge - 75 Citations

Scopus - 79 Citations

Scientific classification

FOS: Engineering and technology > Chemical engineering

Other information

Authenticus ID: P-009-DRC

DOI: 10.1021/ie4041093

Abstract (EN): The industrial application of ionic liquids (ILs) requires the knowledge of their physical properties and phase behavior. This work addresses the experimental determination of the vapor-liquid equilibria (VLE) of binary systems composed of water + imidazolium-based ILs. The ILs under consideration are 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium thiocyanate, 1-butyl-3-methylimidazolium tosylate, 1-butyl-3-methylimidazolium trifluoroacetate, 1-butyl-3-methylimidazolium bromide, 1-butyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium methanesulfonate, and 1-butyl-3-methylimidazolium acetate, which allows the evaluation of the influence of the IL anion through the phase behavior. Isobaric VLE data were measured at 0.05, 0.07, and 0.1 MPa for IL mole fractions ranging between 0 and 0.7. The observed increase in the boiling temperatures of the mixtures is related with the strength of the interaction between the IL anion and water. The Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) was further used to describe the obtained experimental data. The ILs were treated as molecular associating species with two association sites per IL. The model parameters for the pure fluids and the binary interaction parameter k(ij) between water and ILs were determined by a simultaneous fitting to pure-IL densities, water activity coefficients at 298.15 K and VLE data at 0.1 MPa. Pure-IL densities, water activity coefficients, and VLE data were well described by PC-SAFT in broad temperature, pressure, and composition ranges. The PC-SAFT parameters were applied to predict the water activity coefficients at infinite dilution in ILs, and a satisfactory prediction of experimental data was observed.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 12