Patent ID: 9586881
Date: 2017-03-07
CPC Classifications: C07C

Claim:
1. A process for producing propylene glycol monoalkyl ether comprising: contacting propylene oxide and an alcohol in the presence of an alkali or alkaline earth metal alkoxide catalyst to produce an alkoxylation mixture comprising propylene glycol monoalkyl ether; distilling the alkoxylation mixture at a temperature of from about 50° C. to about 200° C. and a pressure of from about 1 psig to about 150 psig to produce a first overhead stream comprising propylene oxide and the alcohol and a first bottoms stream comprising propylene glycol monoalkyl ether; distilling the first bottoms stream to produce a second overhead stream comprising purified propylene glycol monoalkyl ether and a second bottoms stream comprising heavier byproducts; further distilling the second bottoms stream to form a resulting bottoms stream comprising caustic and heavier byproducts; introducing an alkali metal borohydride into at least a portion of the resulting bottoms stream to form an alkali metal borohydride containing stream; and introducing the alkali metal borohydride containing stream into one or more distillations upstream of recovery of the second overhead stream.