Abstract:

Heat-integrated pressure swing distillation for separation of ethyl acetate and ethanol was investigated based on the pressure-sensitivity of the azeotropic composition, and the separation sequence was formed by two columns operating at different pressures. The simulation of separation process was carried out satisfactorily by means of a package of commercial software Aspen Plus and using the thermodynamic model NRTL (non random two liquids) with binary parameters between ethyl acetate and ethanol obtained by experimental data of vapor liquid equilibrium (VLE). The factors affecting the separation efficiency and energy consumption including the number of theoretical plates, feed location and reflux ratio of two columns were analyzed. The results showed that ethyl acetate and ethanol could be efficiently separated by heat-integrated pressure swing distillation, and the optimal conditions were obtained. The heat-integrated pressure swing distillation could save heating steam by 34.7％ compared with conventional pressure swing distillation, which could provide an effective method for the design and energy-saving of azeotropic system separation.

Key words: heat integration, pressure swing distillation, Aspen Plus software, ethyl acetate, ethanol, energy-saving