Isobaric Vapor-Liquid Equilibrium Data for Four Binary Systems of n-Hexane+1,2-Dichloroethane, tert-Butyl Acetate, sec-Butyl Acetate, and n-Propyl Acetate at 101.3 kPa

During the production of ethylene sulfate (DTD) which is a novel electrolyte additive in lithium-ion batteries, a lot of waste liquid containing n-hexane, 1,2-dichloroethane, and DTD was generated. DTD is separated from the mixture through a distillation column and is poured into a crystallizer where the high purity product is obtained by cooling and filtering, while the minimum boiling azeotrope formed by n-hexane and 1,2-dichloroethane cannot be separated by ordinary distillation methods. tert-Butyl acetate, sec-butyl acetate, and n-propyl acetate were selected as entrainers to separate the azeotrope of n-hexane + 1,2-dichloroethane by extractive distillation (ED). The binary interaction parameters (BIPs) of the thermodynamic model are the key parameters used for the conceptual design. The BIPs for the binary systems of 1,2-dichloroethane + sec-butyl acetate/npropyl acetate/tert-butyl acetate have been reported in a previous work. In this work, the vapor-liquid equilibrium (VLE) data for four binary systems (n-hexane + 1,2-dichloroethane/tert-butyl acetate/sec-butyl acetate/n-propyl acetate) were determined at 101.3 kPa using an Ellis vapor-liquid equilibrium device, and the thermodynamic consistency of experimental data was tested by the Fredenslund test and Van Ness test. The VLE data were used for regression of the BIPs of the nonrandom two-liquid (NRTL), universal quasi-chemical (UNIQUAC), and Wilson activity coefficient models.