Controlled continuous purification of propylene oxide by extractive distillation

摘要

In the continuous purification of a propylene oxide feedstock contaminated with water, methanol and acetone, wherein an acetone buffer is established in the column, normal distillation conditions are maintained or restored during or after an upset by continuously monitoring predetermined distillation conditions in the acetone buffer, and adding additional acetone to the extractive distillation column when the monitored distillation condition deviates from a predetermined value by a predetermined amount.