Patent ID: 9593090
Date: 2017-03-14
CPC Classifications: B01D,C07D

Claim:
1. A propylene oxide separation system comprising: a distillation column configured to receive a crude propylene oxide stream, discharge an impurity stream comprising methanol and water, and discharge a bottoms stream comprising a majority of the propylene oxide; a decanter configured to receive at least a portion of the impurity stream and a hydrocarbon solvent to provide for formation in the decanter of an organic phase comprising propylene oxide and hydrocarbon solvent, and an aqueous phase comprising a majority weight percent of the methanol and the water entering in the at least a portion of the impurity stream; a water wash system configured to receive and purge the aqueous phase from the propylene oxide separation system, wherein the organic phase in the decanter is sent to the distillation column, wherein the decanter is a side decanter to the distillation column, and is configured to receive at least a portion of the impurity stream from a liquid side draw of the distillation column; a solvent stripper configured to receive the bottoms stream from the distillation column, wherein the solvent stripper is configured to discharge a solvent-stripper overhead stream comprising a majority of the propylene oxide and; an extraction column configured to subject the solvent-stripper overhead stream from the solvent stripper to a hydrocarbon solvent extraction to remove impurities, wherein the removed impurities comprising one or more of formaldehyde, methyl formate, acetaldehyde and methanol are transferred to the water wash system.