ELECTROCHEMICAL CELL FOR THE PRODUCTION OF SYNTHESIS GAS USING ATMOSPHERIC AIR AND WATER
A method is provided for synthesizing synthesis gas from carbon dioxide obtained from atmospheric air or other available carbon dioxide source and water using a sodium-conducting electrochemical cell. Synthesis gas is also produced by the coelectrolysis of carbon dioxide and steam in a solid oxide fuel cell or solid oxide electrolytic cell. The synthesis gas produced may then be further processed and eventually converted into a liquid fuel suitable for transportation or other applications.
1 . An electrochemical cell for producing synthesis gas comprising:
an anode chamber comprising an electrochemically active anode and a source of water in which the water is decomposed according to the following reaction: ½H2O→¼O2+H++e−, wherein O2 is collected and removed from the anode chamber and wherein the anode chamber has a source of entry for Na2CO3 at a sufficient distance away from the anode such that the Na2CO3 reacts with H+ in solution according to the reaction: H++½Na2CO3→½CO2+½H2O+Na+, and wherein CO2 is collected and removed at a location spaced apart from the anode where O2 is collected and removed;
a cathode chamber comprising an electrochemically active cathode separated from the anode chamber by a membrane which permits transport of Na+ ions, wherein the cathode chamber has a source of water and Na+ ions, in which the water is decomposed according to the following reaction: Na++H2O+e−→NaOH+½H2, wherein H2 is collected and removed from the cathode chamber and wherein NaOH is collected and removed from the cathode chamber; and
means for facilitating the reaction of CO2 and H2 to form synthesis gas comprising CO and H2.
2 . The electrochemical cell according to claim 1 , wherein the source of Na2CO3 comprises Na2CO3 obtained by reacting the NaOH removed from the cathode with a source of CO2.
3 . The electrochemical cell according to claim 2 , wherein the source of CO2 is atmospheric air.
4 . The electrochemical cell according to claim 2 , wherein the source of CO2 is combustion gases.
5 . The electrochemical cell according to claim 2 , wherein the source of CO2 is aerobic decomposition gases.
6 . The electrochemical cell according to claim 1 , wherein the means for facilitating the reaction of CO2 and H2 to form synthesis gas comprises a catalyst exposed to the mixture of CO2 and H2.
7 . The electrochemical cell according to claim 6 , wherein the catalyst comprises a watergas shift catalyst.
8 . The electrochemical cell according to claim 6 , wherein the catalyst comprises a Fischer-Tropsch catalyst.
9 . The electrochemical cell according to claim 6 , wherein the mixture of CO2 and H2 is heated to enable a homogenous gas phase equilibrium reaction.
10 . The electrochemical cell according to claim 6 , the means for facilitating the reaction of CO2 and H2 to form synthesis gas further comprises an oxygen ion conducting electrolysis cell to cause electrolysis of CO2 to form CO, which is mixed with H2 to produce synthesis gas.
11 . The electrochemical cell according to claim 1 , wherein the electrochemical cell is embodied within a plurality of stacked electrochemical cells separated by bipolar plates.
12 . The electrochemical cell according to claim 1 , wherein the membrane which permits transport of Na+ ions comprises a sodium super ionic conductor ceramic material.