Development of Flowsheet of Separation of a Phenol Production Mixture Based on the Analysis of Phase Equilibrium Diagrams

In the large-scale production of phenol by the cumene method, an important constituent is the separation of multicomponent mixtures containing the target products and various impurities. The potential of distillation processes of a specific composition is determined by the structure of the vapor–liquid equilibrium diagram structure. The paper analyzes the phase diagram of a six-component system and its constituents of a smaller dimension. Thermodynamic restrictions on the distillation process associated with the presence of separatric manifolds are established, and ways to overcome them through the use of special techniques are shown. The structures of mixture separation flowsheets are proposed and the columns operation parameters are determined. The use of the re-extractive distillation process is a viable alternative for phenol purification, since it allows the second product of the cumene method, acetone, to be involved in the technological cycle.