System and method for the electrolysis of carbon dioxide
Various embodiments include a system for carbon dioxide electrolysis comprising: an anode and a cathode both connected to a voltage supply, wherein the cathode comprises a gas diffusion electrode adjoined by a gas space and a cathode space; an electrolyte circuit; a gas supply delivering carbon dioxide to the gas space; wherein the gas space has an outlet for an electrolyte, carbon dioxide, and product gases produced by electrolysis; a return connection connecting the outlet to the gas supply; and a pump for circulation of carbon dioxide and product gas in the gas space and the return connection.
1. A system for carbon dioxide electrolysis, the system comprising:
an electrolysis cell having an anode and a cathode both connected to a voltage supply, wherein the cathode comprises a gas diffusion electrode adjoined on a first side by a gas space and on a second side by a cathode space;
an electrolyte circuit adjoining the electrolysis cell, the electrolyte circuit supplying an electrolyte to an anode space and to the cathode space and receiving a least a portion of the electrolyte from the anode space and from the cathode space;
a gas supply delivering carbon dioxide-containing gas to the gas space; wherein the gas space has an outlet for the electrolyte passing through the gas diffusion electrode from the cathode space, carbon dioxide, and product gases produced by the electrolysis cell;
a return connection connecting the outlet to the gas supply;
a pump for circulation of carbon dioxide and product gas in the gas space and the return connection; and
a throttle disposed in a line between the cathode space and the gas space, the throttle limiting a pressure differential between the gas space and the cathode space.
2. The system as claimed in claim 1 , wherein the pump is disposed in the return connection.
3. The system as claimed in claim 1 , wherein the pump is disposed in the gas space.
4. The system as claimed in claim 1 , wherein the throttle maintains the pressure differential between the gas space and the cathode space between 10 and 100 hPa.
5. The system as claimed in claim 1 , wherein the outlet is disposed at a bottom end of the gas space.
6. The system as claimed in claim 1 , wherein the outlet connects to an overflow vessel.
7. The system as claimed in claim 1 , wherein the throttle comprises a pipe arranged at an angle of between 0° and 80° to the vertical.
8. The system as claimed in claim 7 , wherein the pipe is rotatable to set the angle to the vertical.
9. The system as claimed in claim 1 , further comprising turbulence promoters disposed in the gas space.
10. The system as claimed in claim 9 , wherein the turbulence promoters define an air gap of at least 0.1 mm between the turbulence promoters and a surface of the cathode.