Electrolytic process for the production of alkene oxides

Abstract

Alkene oxide can be made in a simple, closed process that uses electrolysis to make bromine and hydroxide from bromide and water. The alkene reacts with bromine and then water to form an alkene bromohydrin, which is dehydrobrominated by hydroxide, regenerating bromide, to give alkene oxide. The main by-product in propylene oxide production is 1,2-dibromopropane, made by propylene reacting with bromine and then bromide. Since formation of 1,2-dibromopropane consumes propylene, electrical power, and bromide, which must be recovered, it is desirable to minimize its formation. It has been discovered that adding carbonate and/or bicarbonate to the bromide electrolyte reduces the formation of 1,2-dibromopropane independently of any pH effect. Carbonate/bicarbonate can be used to reduce formation of dibromo-compounds produced in epoxidation of other alkenes using the electrobromohydrin process. Other carboxylic group and/or carboxylategroup containing materials, which are functionally similar to bicarbonate, can also reduce formation of dibromo-compounds, as demonstrated using ethylene diamine tetraacetic acid disodium salt to reduce formation of 1,2-dibromopropane in propylene oxide production.

Dependencies are inferred from the claim text.