Arrangement for the Electrolysis of Carbon Dioxide

Abstract

Various embodiments may include a system for carbon dioxide electrolysis comprising: an anode; a cathode including a gas diffusion electrode adjoined by a gas space and a cathode space; an electrolyte circuit; a gas supply delivering carbon dioxide-containing gas to the gas space, wherein the gas space includes an outlet for an electrolyte, carbon dioxide, and product gases resulting from the electrolysis; and a throttle connecting the outlet to the electrolyte circuit, wherein the throttle creates a predefined pressure differential between the gas space and the cathode space when a mixture of product gases and liquid electrolyte flows through the throttle.

What is claimed is: 
     
         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;   a gas supply delivering carbon dioxide-containing gas to the gas space;   wherein the gas space includes an outlet for an electrolyte, carbon dioxide, and product gases resulting from the electrolysis; and   a throttle connecting the outlet to the electrolyte circuit, wherein the throttle creates a predefined pressure differential between the gas space and the cathode space when a mixture of product gases and liquid electrolyte flows through the throttle.   
     
     
         2 . A system as claimed in  claim 1 , wherein the throttle comprises a pipe arranged at an angle of between 0° and 80° to the vertical. 
     
     
         3 . A system as claimed in  claim 2 , wherein the angle of the pipe is essentially vertical. 
     
     
         4 . A system as claimed in  claim 2 , wherein the angle of the pipe is adjustable by rotation. 
     
     
         5 . A system as claimed in  claim 2 , wherein an internal diameter of the pipe is at least twice a diameter of a remainder of the connection between the gas space and the electrolyte circuit. 
     
     
         6 . A system as claimed in  claim 1 , further comprising a return connection joining the outlet to the gas supply. 
     
     
         7 . A system as claimed in  claim 6 , further comprising a pump for circulation of carbon dioxide and product gas in the gas space and the return connection. 
     
     
         8 . A system as claimed in  claim 7 , wherein the pump is disposed in the return connection. 
     
     
         9 . A system as claimed in  claim 7 , wherein the pump is disposed in the gas space. 
     
     
         10 . A system as claimed in  claim 1 , wherein the pressure differential between the gas space and the cathode space is kept between 10 and 100 hPa. 
     
     
         11 . A system as claimed in  claim 1 , wherein the outlet in the gas space is disposed at the bottom end. 
     
     
         12 . A system as claimed in  claim 1 , wherein the outlet is connected to an overflow vessel. 
     
     
         13 . A system as claimed in  claim 1 , further comprising turbulence promoters disposed in the gas space. 
     
     
         14 . A system as claimed in  claim 10 , wherein the turbulence promoters define an air gap of at least 0.1 mm between the turbulence promoters and a surface of the cathode.