Electrochemical hydroxide systems and methods using metal oxidation

Abstract

There are provided methods and systems for an electrochemical cell including an anode and a cathode where the anode is contacted with a metal ion that converts the metal ion from a lower oxidation state to a higher oxidation state. The metal ion in the higher oxidation state is reacted with hydrogen gas, an unsaturated hydrocarbon, and/or a saturated hydrocarbon to form products.

1 - 28 . (canceled) 
     
     
         29 . A method, comprising:
 contacting an anode with an anode electrolyte in an electrochemical cell wherein the anode electrolyte comprises metal ions;   contacting a cathode with a cathode electrolyte in the electrochemical cell;   contacting the cathode electrolyte with gaseous carbon dioxide and/or solution of carbon dioxide;   applying a voltage at the anode and the cathode and oxidizing the metal ions from a lower oxidation state to a higher oxidation state at the anode; and   reacting an unsaturated or a saturated hydrocarbon with the anode electrolyte comprising the metal ions in the higher oxidation state.   
     
     
         30 . The method of  claim 29 , wherein the anode electrolyte further comprises saltwater. 
     
     
         31 . The method of  claim 30 , wherein the saltwater comprises water comprising more than 1% chloride content. 
     
     
         32 . The method of  claim 31 , wherein saltwater comprises sodium chloride. 
     
     
         33 . The method of  claim 29 , wherein the metal ion is a metal halide or a metal sulfate that reacts with the unsaturated or the saturated hydrocarbon to form halohydrocarbon or sulfohydrocarbon and the metal halide or the metal sulfate in the lower oxidation state. 
     
     
         34 . The method of  claim 29 , wherein the cathode electrolyte comprises hydroxide, bicarbonate and/or carbonate ions. 
     
     
         35 . The method of  claim 29 , wherein pH of the cathode electrolyte is less than 12. 
     
     
         36 . The method of  claim 29 , wherein the voltage applied across the anode and the cathode is less than 2.9. 
     
     
         37 . The method of  claim 29 , wherein total amount of the metal ions in the anode electrolyte is between 6-12M. 
     
     
         38 . The method of  claim 29 , wherein the anode electrolyte comprises the metal ions in the higher oxidation state in range of 4-7M, the metal ions in the lower oxidation state in range of 0.1-2M, and sodium chloride in range of 1-3M. 
     
     
         39 . The method of  claim 29 , wherein the carbon dioxide is from a gaseous waste stream from an industrial plant. 
     
     
         40 . The method of  claim 29 , wherein the cathode electrolyte comprises water and the cathode is an oxygen depolarizing cathode that reduces oxygen and water to hydroxide ions or the cathode is a hydrogen gas producing cathode that reduces water to hydrogen gas and hydroxide ions. 
     
     
         41 . The method of  claim 29 , wherein the cathode is oxygen depolarized cathode (ODC). 
     
     
         42 . The method of  claim 29 , wherein the metal ion is selected from the group consisting of iron, chromium, copper, tin, silver, cobalt, uranium, lead, mercury, vanadium, bismuth, titanium, ruthenium, osmium, europium, zinc, cadmium, gold, nickel, palladium, platinum, rhodium, iridium, manganese, technetium, rhenium, molybdenum, tungsten, niobium, tantalum, zirconium, hafnium, and combination thereof. 
     
     
         43 . The method of  claim 29 , wherein the metal ion is selected from the group consisting of iron, chromium, copper, and tin. 
     
     
         44 . The method of  claim 29 , wherein the metal ion is copper. 
     
     
         45 . The method of  claim 29 , wherein the metal ion is selected from the group consisting of copper that is converted from Cu +  to Cu 2+ , iron that is converted from Fe 2+  to Fe 3+ , tin that is converted from Sn 2+  to Sn 4+ , chromium that is converted from Cr 2+  to Cr 3+ , and platinum that is converted from Pt 2+  to Pt 4 ′. 
     
     
         46 . A system, comprising:
 an anode chamber comprising an anode in contact with an anode electrolyte wherein the anode electrolyte comprises metal ions wherein the anode is configured to oxidize the metal ions from a lower oxidation state to a higher oxidation state;   a cathode chamber comprising a cathode in contact with a cathode electrolyte wherein the cathode electrolyte comprises alkali;   a gas/liquid contactor operably connected to the cathode chamber and configured to contact carbon dioxide gas or a solution of carbon dioxide with the alkali in the cathode electrolyte;   a power source configured to apply a voltage at the anode and the cathode; and   a reactor operably connected to the anode chamber configured to react an unsaturated or a saturated hydrocarbon with the anode electrolyte comprising the metal ions in the higher oxidation state.   
     
     
         47 . The system of  claim 46 , wherein the solution of carbon dioxide comprises carbonic acid, bicarbonate, carbonate, or combinations thereof. 
     
     
         48 . The system of  claim 46 , wherein the voltage applied across the anode and the cathode is less than 2.9