Electrolysis System and Method for Electrochemical Ethylene Oxide Production

Patent metadata

Field	Value
Publication number	US-2019032228-A1
Application number	US-201716071780-A
Country	US
Kind code	A1
Filing date	Jan 19, 2017
Priority date	Jan 21, 2016
Publication date	Jan 31, 2019
Grant date	—

Abstract

An example electrolysis system for the electrochemical production of ethylene oxide includes an electrolysis cell having an anode in an anode space and a cathode in a cathode space and a gas separation element. The cathode space has a first inlet for carbon monoxide and/or carbon dioxide. The anode space is integrated into an anolyte circuit and the cathode space is integrated into a catholyte circuit. The catholyte circuit has a first product outlet for a reduction product joined to a first connecting conduit connected to the anolyte circuit. The anode space is configured for bringing a reduction product introduced via the first connecting conduit into contact with an oxidation product.

First claim

What is claimed is:

1 . An electrolysis system for the electrochemical production of ethylene oxide, the system comprising:
an electrolysis cell having an anode in an anode space and, a cathode in a cathode space; a gas separation element; wherein the cathode space has a first inlet for carbon monoxide and/or carbon dioxide and is configured for bringing the introduced carbon monoxide and/or carbon dioxide into contact with the cathode; the anode space is integrated into an anolyte circuit and the cathode space is integrated into a catholyte circuit; the catholyte circuit has a first product outlet for a reduction product joined to a first connecting conduit connected to the anolyte circuit; and the anode space is configured for bringing a reduction product introduced via the first connecting conduit into contact with an oxidation product.

2 . The electrolysis system as claimed in claim 1 , further comprising a mixing unit hydrodynamically connected to the anolyte circuit and the catholyte circuit.

3 . The electrolysis system as claimed in claim 1 , wherein the anode space contains bromide ions and is configured for oxidizing bromide to bromine and for taking up a reduction product transferred into the anolyte circuit and bringing it into contact with the bromine.

4 . The electrolysis system as claimed in claim 1 , wherein the gas separation element comprises a diaphragm.

5 . The electrolysis system as claimed in claim 1 , wherein the gas separation element (M) comprises a sulfonated polytetrafluoroethylene.

6 . The electrolysis system as claimed in claim 1 , further comprising:
a second product outlet configured for taking bromine off from an electrolyte mixture conveyed in the anolyte circuit and/or catholyte circuit; and a separate reaction chamber for chemical conversion back into a bromide; wherein the reaction chamber is connected hydrodynamically via a further connecting conduit to the anode space.

7 . A method for the electrochemical production of ethylene oxide by means of an electrolysis system, the method comprising:
introducing carbon monoxide (C) and/or carbon dioxide into a cathode space; reducing at least part of the carbon dioxide to ethylene at a cathode; and transferring at least part of the ethylene from the catholyte circuit via a first product outlet and a subsequent first connecting conduit into an anolyte circuit.

8 . The method as claimed in claim 7 , further comprising:
providing bromine in the anode space; combining the bromine with the ethylene transferred into the anolyte circuit for a reaction to form bromohydrin; and subsequently introducing at least part of the bromohydrin formed into a basic environment and dehydrohalogenating the bromohydrin therein to form ethylene oxide.

9 . The method as claimed in claim 8 , further comprising:
introducing at least part of the bromohydrin formed in the anode space into the catholyte circuit; and dehydrohalogenating the bromohydrin therein to form ethylene oxide.

10 . The method as claimed in claim 7 , further comprising setting the anode space to a pH below 7.

11 . The method as claimed in claim 7 , further comprising setting a pH above 7 in the cathode space or in at least part of the mixing unit.

12 . The method as claimed in claim 7 , further comprising:
taking off at least part of the unutilized and/or reliberated bromine from the electrolyte mixture; converting the bromine outside the electrolysis cell back into a bromide; and adding the bromide to the electrolyte mixture again.

Assignees

• Siemens Ag

Inventors

• Krause Ralf
• Reller Christian
• Schmid Bernhard
• Schmid Günter

Classifications

• C25B13/08

  based on organic materials · CPC title

• C25B1/24

  Halogens or compounds thereof · CPC title

• C07D301/26 Primary

  Y being hydrogen · CPC title

• C07D303/04

  containing only hydrogen and carbon atoms in addition to the ring oxygen atoms · CPC title

• C25B15/08

  Supplying or removing reactants or electrolytes; Regeneration of electrolytes · CPC title