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.