Two-stripper/decanter flowsheet for methanol recovery in the tame reactive-distillation process

The process to produce TAME via reactive distillation requires a methanol-recovery section because the presence of C5/methanol azeotropes means that a significant amount of methanol is present in the distillate from the reactive column. The use of pressure-swing azeotropic distillation and extractive distillation were studied in a previous paper in which both the steady-state design and the plantwide control of the entire process were developed. This paper considers a third alternative flowsheet for the separation of the C5/methanol azeotropes that takes advantage of the heterogeneity of the azeotrope. Two stripping columns and a decanter are used. The total annual cost of this flowsheet is a factor of 4 less than that of the pressureswing system. The system is demonstrated to be easy to control by controlling a tray temperature in each stripping column.