Simulation and optimization of separation of butanol-butyl acetate system

In the process of producing penicillin, pharmaceutical factories will produce a lot of butanol-butyl acetate waste liquid. Therefore, Aspen Plus was used to take NRTL as the physical property method. With the mass fractions of the products, butanol, and butyl acetate, as constraint variables and the minimum heat load of the bottom reboiler as the objective function, the extractive distillation process for separating the butanol - butyl acetate azeotrope was simulated and analyzed. The impacts of parameters such as the feed position and the reflux-to-feed ratio on the separation efficiency were investigated. The results show that the optimal conditions are as follows: for the butanol tower T0101, the feed stage is 6 and the reflux ratio is 2.25; for the butyl acetate tower T0102, the feed stage is 12 and the reflux ratio is 6.5. Under these conditions, the mass fraction of butanol reaches 99.99 % and that of butyl acetate reaches 99.98 %, both of which meet the national superior-grade product standards for industrial use in China. Meanwhile, the total energy consumption cost and environmental pollution emissions were reduced. A preliminary design was carried out for the butyl acetate tower T0102.