Analysis of heat integration, intermediate reboiler and vapor recompression for the extractive distillation of ternary mixture with two binary azeotropes

Abstract

Few works focus on the process intensification of extractive distillation (ED) for the separation of ternary mixture with two binary azeotropes due to its complexity. In this work, double-effect heat integration (DEHI), intermediate reboiler (IR) and vapor recompression (VRC) heat pump ED intensification processes for separating tetrahydrofuran-methanol-water mixture are proposed and optimized via multi-objective genetic algorithm to reduce the CO2 emissions and the total annual cost. Furthermore, each of the ED intensification process is combined with the full use of the sensible heat in entrainer recycling stream. The results showed that all the proposed ED intensification processes are energy-saving than the conventional one. The combined DEHI process is the most economic since its TAC (3 years payback period) is reduced by 25.1% while the combined VRC is the most eco-friendly as its CO2 emissions are saved by 30.4% compared with the conventional ED process.