Method for producing oxirane

A process for manufacturing oxirane by reacting of an olefin with a peroxide compound in the presence of a catalyst and a solvent in at least two reactors arranged in series, each of which contains a portion of the catalyst, according to which a first portion of the olefin, the solvent and the peroxide compound are introduced into a first reactor, an epoxidation of the first portion of the olefin is carried out therein in order to form a first portion of the oxirane, a medium comprising the first portion of oxirane formed, the solvent, the unconverted olefin and, where appropriate, the unconsumed peroxide compound is removed from this reactor and introduced into a distillation column, the majority of the oxirane formed and of the unconverted olefin is collected at the top of the column, the medium depleted in oxirane and containing, where appropriate, the unconsumed peroxide compound is collected at the bottom of the column, the medium depleted in oxirane and another portion of the olefin and optionally another portion of the peroxide compound are introduced into a subsequent reactor, an epoxidation of the other portion of the olefin is carried out therein in order to form another portion of the oxirane, and the other portion of the oxirane thus formed is collected.