Electrolytic System And Reduction Method For Electrochemical Carbon Dioxide Utilization, Alkali Carbonate Preparation And Alkali Hydrogen Carbonate Preparation

Patent metadata

Field	Value
Publication number	US-2018195184-A1
Application number	US-201615739736-A
Country	US
Kind code	A1
Filing date	Jul 30, 2016
Priority date	Jul 3, 2015
Publication date	Jul 12, 2018
Grant date	—

Abstract

The present disclosure relates to electrolysis. The teachings thereof may be embodied in a reduction process and/or an electrolysis system for electrochemical carbon dioxide utilization wherein carbon dioxide is introduced into an electrolysis cell and reduced at a cathode. For example, an electrolysis system for carbon dioxide utilization may comprise: an electrolyzer including an anode in an anode space and a cathode in a cathode space. The cathode space has an entrance for carbon dioxide. The cathode space comprises a catholyte including alkali metal cations. The anode space has an entrance for an anolyte. The anode space comprises an anolyte comprising chlorine anions.

First claim

What is claimed is:

1 . An electrolysis system for carbon dioxide utilization, the system comprising:
an electrolyzer including an anode in an anode space and a cathode in a cathode space; the cathode space has an entrance for carbon dioxide; the cathode space comprises a catholyte including alkali metal cations; the anode space has an entrance for an anolyte; the anode space comprises an anolyte comprising chlorine anions.

2 . The electrolysis system as claimed in claim 1 , further comprising a deposition tank configured for crystallization of an alkali metal hydrogencarbonate and/or alkali metal carbonate out of the catholyte;
wherein the deposition tank includes a product outlet.

3 . The electrolysis system as claimed in claim 2 , further comprising a cooling apparatus for the deposition tank.

4 . The electrolysis system as claimed in claim 2 , further comprising a reservoir connected to the cathode space or the deposition tank to buffer the catholyte.

5 . The electrolysis system as claimed in claim 1 , wherein the catholyte comprises a solvent.

6 . The electrolysis system as claimed in claim 1 , wherein the anolyte includes at least one water-soluble alkali metal salt.

7 . The electrolysis system as claimed in claim 1 , further comprising the anode space connected to a gas separation unit for separation of chlorine gas from the anolyte.

8 . The electrolysis system as claimed in claim 1 , further comprising a cation-conducting membrane separating the anode space and cathode space from one another.

9 . A reduction process for carbon dioxide utilization, the process comprising:
introducing a catholyte and carbon dioxide into a cathode space with a cathode; reducing carbon dioxide at the cathode; introducing an anolyte including chloride anions into an anode space and brought into contact with an anode; wherein the anolyte includes alkali metal cations that migrate into the catholyte; oxidizing chloride anions at the anode to chlorine; separating chlorine from the anolyte as chlorine gas using a gas separation unit; and introducing at least a portion of the catholyte volume into a deposition tank, where an alkali metal hydrogencarbonate and/or alkali metal carbonate crystallizes out.

10 . The reduction process as claimed in claim 9 , further including reducing, at the cathode, carbon dioxide (CO 2 ) to carbon monoxide (CO), ethylene (C 2 H 4 ), methane (CH 4 ), ethanol (C 2 H 5 OH), and/or monoethylene glycol (OHC 2 H 4 OH).

11 . The reduction process as claimed in claim 10 , further comprising converting the hydroxide ions (OH − ) formed in the carbon dioxide reduction to hydrogencarbonate ions (HCO 3 − ) with carbon dioxide (CO 2 ) present in excess.

12 . The reduction process as claimed in claim 9 , further including introducing at least a portion of the catholyte into a deposition tank, where it is cooled down by at least 15 kelvin.

13 . The reduction process as claimed in claim 9 , further comprising introducing at least a portion of the catholyte volume into a deposition tank, where the pH thereof is lowered from above 8 to a pH of 6 or less by blowing in carbon dioxide (CO 2 ).

14 . The reduction process as claimed in claim 9 , further comprising introducing at least a portion of the catholyte volume into a deposition tank, where an alkali metal hydrogencarbonate is crystallized and is subsequently converted to an alkali metal carbonate by heating.

Assignees

• Siemens Ag

Inventors

• Fleischer Maximilian
• Jeanty Philippe
• Krause Ralf
• Magori Erhard
• Maltenberger Anna
• Neubauer Sebastian
• Reller Christian
• Schmid Bernhard
• Schmid Günter
• Volkova Elena
• Wiesner-Fleischer Kerstin

Classifications

• C25B1/01

  Products · CPC title

• C25B3/07

  Oxygen containing compounds · CPC title

• C25B3/03

  Acyclic or carbocyclic hydrocarbons · CPC title

• C25B15/083

  Separating products · CPC title

• C25B3/26

  of carbon dioxide · CPC title