Poly(ethylene terephthalate) (PET) waste accumulation poses significant environmental challenges due to its persistent nature and current management limitations. This study explores the effectiveness of imidazolium-based neoteric solvents [Emim][OAc] and [Bmim][OAc] as catalytic co-solvents in the glycolysis of PET with ethylene glycol (EG). Reaction thermal kinetics showed that both ionic liquids (ILs) significantly enhanced the depolymerization rate of PET compared to traditional methods. The use of [Emim][OAc] offered a lower activation energy of 88.69 kJ·mol⁻¹, thus making the process more energy-efficient. The contribution of key process parameters, including temperature (T), plastic-to-ionic liquid (P/IL) mass ratio, and plastic-to-solvent (P/S) mass ratio, were evaluated by means of a factorial analysis and optimized to achieve the maximum PET conversion for both neoteric solvents. The relevance sequence for both ionic liquids involved the linear factors T and P/S, followed by the interaction factors T×P/S and T×P/IL, with P/IL being the less significant parameter. The optimal conditions, with a predicted conversion of 100%, involved a temperature of 190 °C, with a P/IL of 1:1 and a P/S of 1:2.5, regardless of the IL used as the catalytic co-solvent.

Following the successful utilization of various 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquids (ILs) as effective solvents in the extraction of ethanol, 1-propanol, and 2-propanol from water, we conducted experiments to determine the liquid–liquid equilibria data for the ternary mixture comprising water, ethanol, and 1-decyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([dmim][Tf2N]) at temperatures of 283.2 K, 303.2 K, and 323.2 K under atmospheric pressure. The thermodynamic parameters for both ternary mixtures were calculated using the non-random two-liquid (NRTL) and universal quasichemical (UNIQUAC) models, yielding favorable results across all investigated conditions (rmsd < 0.65%). Subsequently, we explored the efficiency of [dmim][Tf2N] in separating azeotropic mixtures by analyzing the distribution coefficient and selectivity (K₂ and S greater than 1 in all cases, with maximum values of 3.551 and 10.878, respectively). Comparative assessments were made against the performance of various 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ILs and alcohols. The findings underscore the promising capabilities of [dmim][Tf2N] in achieving effective separation, providing valuable insights for potential applications in liquid–liquid extraction processes.