Ternary liquid-liquid equilibria for systems containing (dimethyl carbonate or methyl acetate + methanol + 1-methylmidazole hydrogen sulfate) at 298.15 K and 318.15 K

The separation of methanol from its azeotropes is very important for the production process of vinyl alcohol and dimethyl carbonate. This work describes the feasibility of separating (methanol + methyl acetate) and (methanol + dimethyl carbonate) azeotropes by liquid-liquid extraction using ionic liquid as solvent. The ternary liquid-liquid equilibria (LLE) data for the systems of {methyl acetate + methanol + 1-methylmidazole hydrogen sulfate ([MIM]HSO4]}, {dimethyl carbonate + methanol + [MIM][HSO4]} were measured at 298.15 K and 318.15 K under atmospheric pressure. The separation factor and distribution coefficient were calculated from the experimental LLE results to evaluate the separation performance. The influence of temperature on the LLE was investigated and discussed. The experimental LLE data were satisfactorily correlated by NRTL and UNIQUAC models, the binary interaction parameters were obtained and the calculated LLE data were compared with the experimental results.