Abstract: A simulation study was conducted on the separation process of n-hexane/acetone azeotrope using a coupled method of liquid-liquid extraction and conventional distillation, with water as the extractant and Aspen Plus V11 as the simulation software. First, the operating parameters of the extraction process, such as the number of theoretical plates, solvent ratio, extraction temperature, and residual extractant, were investigated. Further optimization was performed on the feed plate location, total number of plates, and overhead operating pressure of the distillation column. Finally, the temperature of the circulating extractant and the recovery rate of n-hexane at the top of the extraction column were optimized to minimize the operating energy consumption of the coupled separation process for n-hexane/acetone. The simulation results showed that the operating energy consumption of the coupled system was minimized when the extraction column had 3 theoretical plates, a solvent ratio of 2.31 and a circulating extractant temperature of 15°C, and the distillation column had 35 theoretical plates and 33 feed plates, a reflux ratio of 2.66 and an overhead operating pressure of 0.01 MPag. Compared to using ethylene glycol monomethyl ether for extractive distillation to separate the azeotrope, this method can reduce the energy consumption by 19.5%, making it an environmentally friendly and more energy-efficient separation method.

Key words: n-hexane/acetone azeotrope, liquid-liquid extraction, distillation, operation optmization