In the method for the epoxidation of an olefin, the olefin is continuously reacted with hydrogen peroxide in a mixed reactor in the presence of a water soluble epoxidation catalyst, comprising a manganese complex, the reaction is carried out in a reaction mixture comprising an aqueous liquid phase and an organic liquid phase with mixing of the liquid phases, reaction mixture is continuously withdrawn from the mixed reactor and separated into a separated aqueous phase and a separated organic phase, and part of the separated aqueous phase is continuously recycled into the mixed reactor, with the combined hold-up time of aqueous phase in withdrawing, separating phases and recycling aqueous phase being kept at less than 15 minutes.

In the method for the epoxidation of an olefin, the olefin is continuously reacted with hydrogen peroxide in a mixed reactor in the presence of a water soluble epoxidation catalyst, comprising a manganese complex, the reaction is carried out in a reaction mixture comprising an aqueous liquid phase and an organic liquid phase with mixing of the liquid phases, reaction mixture is continuously withdrawn from the mixed reactor and separated into a separated aqueous phase and a separated organic phase, and part of the separated aqueous phase is continuously recycled into the mixed reactor, with the combined hold-up time of aqueous phase in withdrawing, separating phases and recycling aqueous phase being kept at less than 15 minutes.

In the method for the epoxidation of an olefin, the olefin is continuously reacted with hydrogen peroxide in a mixed reactor in the presence of a water soluble epoxidation catalyst, comprising a manganese complex, the reaction is carried out in a reaction mixture comprising an aqueous liquid phase and an organic liquid phase with mixing of the liquid phases, reaction mixture is continuously withdrawn from the mixed reactor and separated into a separated aqueous phase and a separated organic phase, and part of the separated aqueous phase is continuously recycled into the mixed reactor, with the combined hold-up time of aqueous phase in withdrawing, separating phases and recycling aqueous phase being kept at less than 15 minutes.

Provided is a composition containing an unsaturated compound and an organic halide, wherein a content of the organic halide in terms of halogen element, based on a content of the unsaturated compound, is 1 ppm by mass or more and 10,000 ppm by mass or less.

Provided is a composition containing an unsaturated compound and an organic halide, wherein a content of the organic halide in terms of halogen element, based on a content of the unsaturated compound, is 1 ppm by mass or more and 10,000 ppm by mass or less.