In the production of poly(vinyl alcohol),
the raw materials methyl
acetate (MeOAc) and methanol (MeOH) exist as a homogeneous azeotropic
mixture. Twenty-five kinds of ionic liquids, composed of five types
of cations and five types of anions, were studied using the COSMO-SAC
method. The σ-profile data for each component and the selectivity
at infinite dilution (<i>S</i><sup>∞</sup>) were
calculated and analyzed, respectively. 1-Hexyl-3-methylimidazolium
chloride ([HMIM][Cl]) and 1-butyl-3-methylimidazolium chloride ([BMIM][Cl])
were selected as suitable entrainers based on the COSMO-SAC method.
The binary interaction parameters of the NRTL model of the MeOAc/ionic
liquid and MeOH/ionic liquid systems were regressed. The conceptual
design for the separation of MeOAc and MeOH using ionic liquids as
entrainers was investigated. The comparison of two processes using
two entrainers was carried out from an economic perspective. The total
annual cost (TAC) of the process using [HMIM][Cl] as an entrainer
can be reduced by 16.5% compared with that of the process using [BMIM][Cl].
The results indicated that the COSMO-SAC method is feasible for screening
ionic liquids as optimal entrainers. This work could provide theoretical
instruction for further industrial applications using ionic liquids
as solvents via COSMO-SAC computer-aided screening
