Patent ID: 8093412
Filing Date: 2012-01-10
Classification: C07D

Abstract:
1. A method of purifying propylene oxide, which comprises the following steps: (1) subjecting propylene oxide containing methyl formate as an impurity to extractive distillation using a hydrocarbon of 7 to 10 carbon atoms as an extractant with an extractive distillation column, (2) adding water to the distillate from the overhead of the extractive distillation column followed by separating into an oil layer and an aqueous layer, (3) recycling the oil layer to the extractive distillation column, (4) removing the aqueous layer outside the system, contacting the aqueous layer with the same extractant used in the extractive distillation, subsequently separating into an oil layer and an aqueous layer, and supplying the oil layer to an extractive distillation column, and (5) obtaining propylene oxide in which a methyl formate concentration is reduced, as a bottom liquid of the extractive distillation column.