Alkaline production using a gas diffusion anode with a hydrostatic pressure

Abstract

An electrochemical system comprising a first cation exchange membrane in contact with a gas diffusion anode and configured to separate the gas diffusion anode from an anode electrolyte; a cathode in contact with a cathode electrolyte; and a second cation ion exchange membrane configured to separate the cathode electrolyte from the anode electrolyte. In the system, an external pressure system is configured to apply a pressure against the first cation exchange membrane through the anode electrolyte, and an alkaline solution is produced in the cathode electrolyte by applying a voltage across the anode and cathode; in some embodiments, carbon dioxide is requested by reaction with the cathode electrolyte.

1 . An electrochemical system comprising:
 a first cation exchange membrane in contact with a gas diffusion anode and configured to separate the gas diffusion anode from an anode electrolyte;   a cathode in contact with a cathode electrolyte; and   a second cation ion exchange membrane configured to separate the cathode electrolyte from the anode electrolyte.   
     
     
         2 . The electrochemical system of  claim 1 , comprising an external pressure system configured to apply a pressure on the anode electrolyte and the first cation exchange membrane. 
     
     
         3 . (canceled) 
     
     
         4 . (canceled) 
     
     
         5 . The electrochemical system of  claim 2 , wherein the cathode electrolyte comprises added carbon dioxide. 
     
     
         6 . (canceled) 
     
     
         7 . The electrochemical system of  claim 5 , wherein the gas diffusion anode comprises a substrate comprising a catalyst configured to catalyze oxidization of hydrogen gas to protons. 
     
     
         8 . The electrochemical system of  claim 7 , wherein the substrate comprises a first side in contact with the hydrogen and an opposed second side in contact with the first cation exchange membrane. 
     
     
         9 . (canceled) 
     
     
         10 . (canceled) 
     
     
         11 . (canceled) 
     
     
         12 . (canceled) 
     
     
         13 . (canceled) 
     
     
         14 . (canceled) 
     
     
         15 . (canceled) 
     
     
         16 . The electrochemical system of  claim 8 , wherein first cation exchange membrane is configured to migrate protons from the substrate into the anode electrolyte on application of a voltage across the substrate and the cathode. 
     
     
         17 . The electrochemical system of  claim 16 , wherein the system is configured to produce hydrogen gas and hydroxyl ions at the cathode on applying a voltage across the substrate and cathode. 
     
     
         18 . The electrochemical system of  claim 17 , wherein the system is configured to migrate cations from the anode electrolyte into the cathode electrolyte through the second cation exchange membrane. 
     
     
         19 . (canceled) 
     
     
         20 . The electrochemical system of  claim 18 , wherein the system is configured to migrate hydroxide ions from the cathode into the cathode electrolyte. 
     
     
         21 . The electrochemical system of  claim 20 , wherein the cathode electrolyte comprises carbonate ions and/or bicarbonate ions. 
     
     
         22 . (canceled) 
     
     
         23 . (canceled) 
     
     
         24 . The electrochemical system of  claim 21 , further comprising a hydrogen delivery system configured to direct hydrogen gas to the anode from the cathode. 
     
     
         25 . (canceled) 
     
     
         26 . The electrochemical system of  claim 24 , operatively connected to a waste gas system and configured to dissolve carbon dioxide from the waste gas and into the cathode electrolyte. 
     
     
         27 . The electrochemical system of  claim 26 , configured to produce a carbonate or bicarbonate by mixing the cathode electrolyte with a divalent cation solution comprising calcium or magnesium ions. 
     
     
         28 . (canceled) 
     
     
         29 . The electrochemical system of  claim 27 , configured to dissolve a mineral with the anode electrolyte to produce the divalent cation solution. 
     
     
         30 . An electrochemical method comprising:
 separating a gas diffusion anode from an anode electrolyte using a first cation exchange membrane in contact with the gas diffusion anode;   separating the anode electrolyte from a cathode electrolyte contacting a cathode using a second cation exchange membrane;   applying an external hydrostatic pressure on the anode electrolyte;   producing an alkaline solution in the cathode electrolyte without producing a gas at the anode by applying a voltage across the gas diffusion anode and cathode.   
     
     
         31 . (canceled) 
     
     
         32 . The electrochemical method of  claim 30 , comprising adding carbon dioxide to the cathode electrolyte. 
     
     
         33 . The electrochemical method of  claim 32 , comprising oxidizing hydrogen gas to protons at the gas diffusion anode and migrating protons from the gas diffusion anode through the first cation exchange membrane into the anode electrolyte. 
     
     
         34 . (canceled) 
     
     
         35 . (canceled) 
     
     
         36 . The electrochemical method of  claim 33 , comprising migrating sodium or potassium ions from the anode electrolyte into the cathode electrolyte through the second cation exchange membrane. 
     
     
         37 . (canceled) 
     
     
         38 . The electrochemical method of  claim 36 , comprising producing hydroxyl ions and hydrogen gas at the cathode, migrating hydroxyl ions from the cathode into the cathode electrolyte and directing hydrogen gas from the cathode to the gas diffusion anode. 
     
     
         39 . (canceled) 
     
     
         40 . (canceled) 
     
     
         41 . (canceled) 
     
     
         42 . The electrochemical method of  claim 38 , comprising contacting the substrate at a first side with hydrogen and contacting the substrate at an opposed second side with the first cation exchange membrane. 
     
     
         43 . (canceled) 
     
     
         44 . (canceled) 
     
     
         45 . (canceled) 
     
     
         46 . (canceled) 
     
     
         47 . (canceled) 
     
     
         48 . (canceled) 
     
     
         49 . (canceled) 
     
     
         50 . The electrochemical method of  claim 42 , wherein the system is configured to migrate cations from the anode electrolyte into the cathode electrolyte through the second cation exchange membrane. 
     
     
         51 . (canceled) 
     
     
         52 . The electrochemical method of  claim 50 , wherein the cathode electrolyte comprises carbonate ions and/or bicarbonate ions. 
     
     
         53 . (canceled) 
     
     
         54 . (canceled) 
     
     
         55 . (canceled) 
     
     
         56 . The electrochemical method of  claim 52 , wherein carbon dioxide in ambient air is excluded from the cathode electrolyte. 
     
     
         57 . (canceled) 
     
     
         58 . The electrochemical method of  claim 56 , comprising contacting the cathode electrolyte with a divalent cation solution comprising magnesium ions or calcium ions to produce a carbonate or bicarbonate. 
     
     
         59 . (canceled) 
     
     
         60 . The electrochemical method of  claim 58 , comprising dissolving a mineral with the anode electrolyte to produce the divalent cation solution.