Extractive distillation of propylene oxide containing halohydrocarbon impurities

Claim 1

A PROCESS FOR THE PURIFICATION OF PROPYLENE OXIDE FROM MIXTURE THEREOF WITH A LIGHT HALOHYDROCARBON IMPURITY OBTAINED IN THE PREPARATION OF THE PROPYLENE OXIDE BY DEHYDROHALOGENATION OF PROPYLENE CHLOROHYDRIN, WHICH COMPRISES SUBJECTING SAID MIXTURE TO A FITRST DISTILLATION STEP IN WHICH THE INPURE PROPYLENE OXIDE IS DISTILLED BY AN EXTRACTIVE DISTILLATION IN A COLUMN INTO WHICH WATER AN EXTRACTIVE DISTILLATION IN A COLUMN INTO WHICH WATER AS ANN EXTRACTANT IS ADMITTED AT AN UPPER FEED POINT, AND THE IMPURE MIXTURE IS ADMITTED AT A LOWER FEED FROM THE MOVING AN AQUEOUS SOLUTION SUBSTANTIALLY FREE FROM THE LIGHT HALOHYDROCARBON IMPURITY AS A BOTTOM PRODUCT, DISTILLONG THE BOTTOM PRODUCT IN A SECOND DISTILLATION COLUMN AND REMOVING THE PROPYLENE OXIDE SUBSTANTIALLY WATER FREE AS THE TOP PRODUCT.