Comparison of Extractive and Pressure-Swing Distillation for Separation of Tetrahydrofuran-Water Mixture

Tetrahydrofuran (THF) is widely used in many processes as solvent or chemical intermediate. It is necessary to separate mixture of THF-water, because in most commercial production processes, THF is produced from its water mixture. However, the above mixture cannot be separated with ordinary distillation, since THF and water can form azeotrope. Instead, extractive distillation (ED) and pressure-swing distillation (PSD) have been widely applied for commercial separation of mixture of THF-water. In this paper, Aspen Plus simulator is used to simulate extractive distillation and pressure-swing distillation process for separation of mixture of THF-water. Economic analysis is carried out by Aspen Process Economic Analyzer (APEA) for the two processes. The conclusion obtained based on the above process simulation and analysis is that the total annualized cost of the extractive distillation is slightly lower than that of pressure-swing distillation. The results obtained provide useful references for commercial separation of mixture of THF and water.