Screening of ionic liquids as sustainable catalyst for production of n-butyl acetate using COSMO-RS model

Context

A total of 42 cations and 32 anions resulting in 1344 possible combinations were screened for green esterification process via the conductor-like screening model for real solvents (COSMO-RS model). The esterification reactants and products; n-butanol (n-BuOH), acetic acid (HAc), and n-butyl acetate (n-BuAc) in different combination of cation and anions were used to predict the activity coefficient at infinite dilution (IDAC) with the help of screening charge density. From the predicted IDAC values, the selectivity (S), capacity (C), and performance index (PI) were calculated to screen potential ionic liquids (ILs) for the green esterification process. Further, the σ-profile, and σ-potential of ILs, reactants, and products were generated and analysed.

Methods

Molden Visualization Software, Gaussian 03 software, COSMOthermX (Version:19.0.5) were used to predict IDAC, sigma profile, and sigma potential. Hartree–Fock level and basis set 6-31G*. Density functional theory (DFT) with PBVP86 in combination with the basis set SVP (split valence polarised) and the density fitting basis set DGA1 (density gradient approximation)—#P BVP86/SVP/DGA1.