Membrane-supported catalyst removal in the epoxidation of cyclic unsaturated C12 compounds, for example cyclododecene (CDEN)

A method to prepare an epoxidized cyclic unsaturated compound comprising twelve carbon atoms, comprising:

• epoxidizing a cyclic unsaturated compound comprising 12 carbon atoms with hydrogen peroxide in a two phase organic aqueous system in the presence of a homogeneous catalyst and phase transfer reagent;
• separating and removing the aqueous phase to obtain an organic phase containing the epoxidized cyclic unsaturated compound comprising twelve carbon atoms, the homogeneous catalyst and the phase transfer reagent;
• contacting the organic phase with a membrane under a transmembrane pressure of 5 to 80 bar to obtain a permeate comprising the epoxidized cyclic unsaturated compound comprising twelve carbon atoms and a retentate comprising the homogeneous catalyst and phase transfer reagent;
• wherein the membrane is a composite membrane comprising a support material and a membrane separation-active layer comprising a crosslinked silicone acrylate and
• the homogeneous catalyst comprises an oxide, a mixed oxide, an oxoacid, a salt of an oxoacid, a carbonyl derivative, a sulphide, a chloride, an oxychloride or a stearate of an element selected from the group consisting of tungsten, molybdenum and vanadium.