Energy-Efficient Vacuum-Distillation Process for Separating Diluted Acetonitrile-Water Mixture: Rigorous Design with Experimental Verification from Ternary Liquid-Liquid Equilibrium Data

According to the feature that composition of the Azeotrop could be changed with the change of pressure, the method of pressure-swing distillation was applied to separate the azeotrope of acetonitrile-water and obtain high purity acetonitrile. A simulation model of pressure-swing distillation system was established by chemical engineering software Aspen Plus to get initial results. Meanwhile, the influence of process parameters such as reflux ratio, feed stage, tower pressure and distillate flow rate on the rectification effect was analyzed by the model analysis tools. Ultimately, the optimization model of minimum energy consumption of distillation process was established under the premise assuring the quality of products to obtain energy- efficient optimizing operation parameters. The results showed that the simulation met technology requirements, saved energy 25% and laid the foundation for design and implementation of real-time optimization control system.