METHOD OF ELECTROCHEMICALLY PRODUCING EPOXIDES

摘要

Described is a method of electrochemically converting α-halohydrins, e.g., 1-chloro-2-hydroxypropane and 1,3-dichloro-2-hydroxypropane, to epoxides, e.g., propylene oxide and epichlorohydrin. A three compartment electrolytic cell (2) is provided having (1) a catholyte compartment (13) containing a cathode assembly comprising a cathode (28) and an anion exchange membrane (31), (2) an anode compartment containing an anode assembly comprising either (a) a hydrogen consuming gas diffusion anode (22) and a current collecting electrode (19) or (b) a hydrogen consuming gas diffusion anode which is fixedly held between a hydraulic barrier and a current collecting electrode, and (3) an intermediate compartment (16) separated from the catholyte and anode compartments by the anion exchange membrane and either (i) the hydrogen consuming gas diffusion anode or (ii) the hydraulic barrier respectively. An aqueous solution of α-halohydrin is charged to the catholyte compartment, while hydrogen gas is charged to the anode compartment and an aqueous electrolyte solution is charged to the intermediate compartment. Direct current is passed through the electrolytic cell and an aqueous solution comprising epoxide is removed from the catholyte compartment.