Efficient Single-Column Extractive Distillation Process Achieved through Vapor–Liquid Separation of Feed

The composition of azeotropic mixtures has the probability to deviate significantly from their azeotropic point. This study proposes a single-column side-stream extractive distillation (ED) combined with a front-side reboiler process to address the separation challenges posed by such azeotropic mixtures. The proposed process integrates the functions of preconcentration, ED, and entrainer recovery within a single distillation column. This integrated process improves economic performance and reduces energy consumption in ED. The universality of the proposed method was validated through three case studies: acetone/n-heptane, dichloromethane/ethanol, and methanol/toluene. Notably, our process exhibits a significantly higher potential for heat integration compared with the conventional single-column side-stream ED scheme. It reduces the compression ratio and power of the compressor during the vapor recompression process. Moreover, the process is simple, avoiding unnecessary complexity.