Dividing wall column–salting-out–pervaporation intensified process for low-carbon alcohols separation

Separating low-carbon alcohols (C₁-C₄) produced from coal-based synthesis gas is highly energy-intensive due to the presence of C₂-C₄/water azeotrope. To address this challenge, this study proposed a Dividing wall column–Salting-out–Pervaporation (DWC–SO–PV) process to save energy. In this process, DWC reduced the number of distillation columns in the preliminary separation and C₂-C₄ product separation processes, and SO broke the C₂-C₄/water azeotrope and removed a large amount of water. Furthermore, PV achieved complete dehydration of the C₂-C₄/water azeotrope. Optimal operating parameters of DWC were determined using the response surface methodology coupled particle swarm optimization (RSM-PSO), and dehydration conditions of C₂-C₄ were simulated through experimental data. The DWC–SO–PV process confers major benefits over conventional distillation: up to 48.74% reduced total annual costs and up to 50.01% energy savings. This study offered significant advancements in the dehydration of low-carbon alcohols, contributing to reduce energy consumption of coal products.