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 saltwater and metal halide;   contacting an oxygen depolarizing cathode with a cathode electrolyte in the electrochemical cell;   applying a voltage to the anode and the oxygen depolarizing cathode and oxidizing the metal halide from a lower oxidation state to a higher oxidation state at the anode; and   halogenating an unsaturated hydrocarbon or a saturated hydrocarbon with the anode electrolyte comprising the metal halide in the higher oxidation state in an aqueous medium to result in a halohydrocarbon and the metal halide in the lower oxidation state.   
     
     
         30 . The method of claim  1 , further comprising forming an alkali or water at the oxygen depolarizing cathode. 
     
     
         31 . The method of claim  1 , wherein the cathode electrolyte comprises water and the oxygen depolarizing cathode reduces oxygen and water to hydroxide ions; or the cathode electrolyte comprises hydrochloric acid and the oxygen depolarizing cathode reacts hydrochloric acid and oxygen gas to form water. 
     
     
         32 . The method of claim  1 , wherein metal ion in the metal halide 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. 
     
     
         33 . The method of claim  1 , wherein metal ion in the metal halide is selected from the group consisting of iron, chromium, copper, and tin. 
     
     
         34 . The method of claim  1 , wherein metal ion in the metal halide is copper. 
     
     
         35 . The method of claim  1 , wherein the lower oxidation state of metal ion in the metal halide is 1+, 2+, 3+, 4+, or 5+ and the higher oxidation state of metal ion in the metal halide is 2+, 3+, 4+, 5+, or 6+. 
     
     
         36 . The method of claim  1 , wherein metal ion in the metal halide is copper that is converted from Cu +  to Cu 2+ , metal ion in the metal halide is iron that is converted from Fe 2+  to Fe 3+ , metal ion in the metal halide is tin that is converted from Sn 2+  to Sn 4+ , metal ion in the metal halide is chromium that is converted from Cr 2+  to Cr 3+ , metal ion in the metal halide is platinum that is converted from Pt 2+  to Pt 4+ , or combination thereof. 
     
     
         37 . The method of claim  1 , wherein no gas is used or formed at the anode. 
     
     
         38 . The method of claim  1 , further comprising adding a ligand to the anode electrolyte. 
     
     
         39 . The method of claim  1 , wherein the metal halide in the lower oxidation state is re-circulated back to the anode electrolyte. 
     
     
         40 . The method of claim  1 , wherein the anode electrolyte comprising the metal halide in the higher oxidation state further comprises the metal halide in the lower oxidation state. 
     
     
         41 . The method of claim  1 , wherein the unsaturated hydrocarbon is a C2-C10 alkene or the saturated hydrocarbon is C2-C10 alkane. 
     
     
         42 . The method of claim  1 , wherein the unsaturated hydrocarbon is ethylene, propylene, or butylene which reacts with the anode electrolyte comprising the metal halide in the higher oxidation state to form ethylene dichloride, propylene dichloride or 1,4-dichlorobutane, respectively. 
     
     
         43 . The method of  claim 42 , further comprising forming vinyl chloride monomer from the ethylene dichloride and forming poly(vinyl chloride) from the vinyl chloride monomer. 
     
     
         44 . The method of claim  1 , wherein the saturated hydrocarbon is methane, ethane, or propane. 
     
     
         45 . The method of claim  1 , wherein the saltwater comprises water comprising more than 1% chloride content. 
     
     
         46 . The method of claim  1 , wherein the saltwater comprises sodium chloride. 
     
     
         47 . 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 an oxygen depolarizing cathode in contact with a 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.   
     
     
         48 . The system of  claim 47 , wherein the cathode electrolyte comprises water and the oxygen depolarizing cathode is configured to reduce oxygen and water to hydroxide ions; or the cathode electrolyte comprises hydrochloric acid and the oxygen depolarizing cathode is configured to react hydrochloric acid and oxygen gas to form water.