Alkylene oxide separation systems, methods, and apparatuses

摘要

A propylene oxide separation system that comprises a distillation column, a decanter, and water wash system. The distillation column is configured to receive a crude propylene oxide stream, discharge an impurity stream that comprises methanol and water, and discharge a bottoms stream that comprises a majority of the propylene oxide entering in the crude propylene oxide stream. The decanter is 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 and an aqueous phase. The organic phase comprises propylene oxide and hydrocarbon solvent, and is sent to the distillation column. The aqueous phase comprises a majority weight percent of the methanol and the water entering in the impurity stream. The water wash system is configured to receive and purge the aqueous phase from the propylene oxide separation system.

主权项

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.