Purification of propylene oxide by cosolvent extractive distillation

摘要

An extractive distillation agent consisting essentially of a mixture of triethylene glycol with a lower boiling cosolvent selected from the group consisting of 2-methyl-2,4-pentanediol, tertiary butyl alcohol and ethylene glycol is fed to an extractive distillation column used for the distillation of propylene oxide contaminated with water, acetone and methanol to obtain an overhead distillate fraction consisting of essentially anhydrous propylene oxide contaminated with reduced quantities of acetone and methanol, and a heavier bottoms distillation fraction containing substantially all of the extractive distillation agent, water and acetone and some of the methanol introduced into the distillation column.