Abstract: Various embodiments may include an electrolyzer for electrochemical utilization of carbon dioxide comprising: electrolysis cell defining an anode space and a cathode space; an anode in the anode space; a cathode in the cathode space; a first cation-permeable membrane disposed between the anode space and the cathode space; and a second anion-selective membrane disposed between the first cation-permeable membrane and the cathode. The anode directly adjoins the first cation-permeable membrane. The second anion-selective membrane directly adjoins the first cation-permeable membrane and the second anion-selective membrane directly adjoins the cathode.

Abstract: Various embodiments include a method for electrochemical utilization of carbon dioxide comprising: reducing carbon dioxide to a product gas in an electrolysis cell of an electrolyzer; delivering the product gas comprising carbon dioxide into a gas scrubbing apparatus; scrubbing the product gas to remove carbon dioxide using an absorbent in the gas scrubbing apparatus; regenerating the absorbent in an electrodialysis cell of an electrodialysis unit; at least partly recycling the regenerated absorbent into the gas scrubbing apparatus; and at least partly recycling the carbon dioxide released during the regenerating as reactant gas into the electrolyzer.

Abstract: Various embodiments may include an electrolyzer for electrochemical utilization of carbon dioxide comprising: electrolysis cell defining an anode space and a cathode space; an anode in the anode space; a cathode in the cathode space; a first cation-permeable membrane disposed between the anode space and the cathode space; and a second anion-selective membrane disposed between the first cation-permeable membrane and the cathode. The anode directly adjoins the first cation-permeable membrane. The second anion-selective membrane directly adjoins the first cation-permeable membrane and the second anion-selective membrane directly adjoins the cathode.

Abstract: Various embodiments may include an electrolyzer for electrochemical utilization of carbon dioxide comprising: an electrolysis cell defining an anode space and a cathode space; an anode; a cathode; a first cation-permeable membrane disposed between the anode space and the cathode space; and a layer comprising an anion-selective polymer disposed between the first membrane and the cathode. The anode directly adjoins the first cation-permeable membrane and the layer covers at least part of the cathode but not all of the cathode.

Abstract: Various embodiments include a CO2 electrolyzer comprising: a gas space adjoining a cathode comprising a gas diffusion electrode adjoining a cathode space; an anode in an anode space; a membrane separating the cathode space from the anode space; a feed apparatus feeding reactant gas into the gas space; a mixing vessel for at least partial joint accommodation of the anolyte and the catholyte; and a connection line between the gas separating region and the gas space. The mixing vessel includes a gas separating region closed off with respect to a surrounding atmosphere. The cathode space accommodates a catholyte and the anode space accommodates an anolyte.

Abstract: Various embodiments include a method for producing hydrocarbons, the method comprising: producing carbon monoxide and carbon dioxide with addition of oxygen in a first reaction unit; fermenting the carbon monoxide, the carbon dioxide, and hydrogen in a second reaction unit; adding biogas provided from a biogas system and oxygen from an electrolyzer as reactants to the first reaction unit; and adding hydrogen from the electrolyzer as a reactant to the second reaction unit.