Extractive distillation separation of isopropanol - isopropyl acetate azeotrope: Vapor-liquid equilibrium measurement and process optimization

In industrial production, isopropanol (IPA) and isopropyl acetate (IPAC) serve as raw materials and products for each other. Due to the inability to achieve a 100 % conversion rate of the products, they usually exist as a mixture. However, IPA and IPAC can form a binary azeotropic mixture, making it difficult to separate them through conventional separation methods. In the current work, extractive distillation is being considered for the separation of IPA and IPAC using entrainers such as 4-methyl-2-pentanone (MIBK), chlorobenzene and butyl acetate. The vapor-liquid equilibrium (VLE) data of the binary systems (IPAC + MIBK / chlorobenzene / butyl acetate) at 101.3 kPa were determined, and the results passed the thermodynamic consistency tests (van Ness and pure component). Using three commonly used activity coefficient models (NRTL, UNIQUAC and Wilson) to correlate and regress the data, the results indicate that the vapor phase and temperature deviations are respectively less than 0.0037 and 0.1847 K. Afterwards, suitable entrainer was screened using the binary interaction parameters of regression, and an extractive distillation (ED) process was designed. The products purity reached 99.6 wt%, and the parameters were optimized with the goal of minimizing the bottom heat duty.