Method and system for low voltage electrochemical gas to liquids production

Abstract

A method for producing methanol from methane in which methane is provided to an anode electrode having a metal oxide catalyst disposed on an anode side of an electrolyte membrane, thereby producing methanol and electrons on the anode side. The electrons are conducted to a cathode electrode such as having an oxygen reduction catalyst disposed on a cathode side of the electrolyte membrane, thereby transforming oxygen and water provided to the cathode side to hydroxide ions.

What is claimed is: 
     
         1 . A method for converting methane to methanol, the method comprising:
 providing a reactor including an anode, a cathode, and a membrane between the anode and the cathode;   feeding methane to the anode, and converting the methane to form methanol and electrons;   passing the electrons to the cathode and feeding water and oxygen to the cathode, reducing the oxygen and producing hydroxide ions;   transporting the hydroxide ions through the membrane to the anode; and   recovering the methanol from the reactor.   
     
     
         2 . The method of  claim 1  wherein reaction at the cathode is an oxygen reduction reaction via an oxygen reduction catalyst. 
     
     
         3 . The method of  claim 2  wherein said oxygen reduction catalyst is selected from the group consisting of cobalt polypyrrole, silver on carbon, Pt, and MnO 2 . 
     
     
         4 . The method of  claim 1  wherein said feeding of water and oxygen to the cathode comprises at least one of bubbling an oxygen-containing gas through water to the cathode and feeding a humidified oxygen-containing gas to the cathode. 
     
     
         5 . The method of  claim 4  wherein said feeding of water and oxygen to the cathode comprises bubbling an oxygen-containing gas through water to the cathode. 
     
     
         6 . The method of  claim 5  wherein the oxygen-containing gas comprises air. 
     
     
         7 . The method of  claim 5  wherein the oxygen-containing gas comprises O 2 . 
     
     
         8 . The method of  claim 4  wherein said feeding of water and oxygen to the cathode comprises feeding a humidified oxygen-containing gas to the cathode. 
     
     
         9 . The method of  claim 8  wherein the oxygen-containing gas comprises air. 
     
     
         10 . The method of  claim 8  wherein the oxygen-containing gas comprises O 2 . 
     
     
         11 . The method of  claim 1  comprising performing the following net chemical reaction at the cathode:
   ½O 2 +H 2 O+2 e   − →2OH − .
 
 
     
     
         12 . The method of  claim 1  comprising performing the following overall reactor reaction:
   2CH 4 +O 2 →2CH 3 OH.
 
 
     
     
         13 . A system for converting methane to methanol said system comprising:
 a reactor having an anode, a cathode, and a membrane between the anode and the cathode; the membrane being at least one being porous or having ionic conducting sites, the membrane allowing transport of hydroxide ions from the cathode to the anode;   a source of methane interconnected to the anode to permit the feed of methane to the anode; and   a source of oxygen and a source of water interconnected to the cathode to permit the feed of water and oxygen to the cathode.   
     
     
         14 . The system of  claim 13  wherein the cathode includes an oxygen reduction catalyst. 
     
     
         15 . The system of  claim 14  wherein the oxygen reduction catalyst is selected from the group consisting of cobalt polypyrrole, silver on carbon, Pt, and MnO 2 . 
     
     
         16 . The system of  claim 13  wherein the source of oxygen and the source of water interconnected to the cathode comprises one of bubbling air through water to the cathode and feeding humidified air to the cathode. 
     
     
         17 . The system of  claim 16  wherein the source of oxygen and the source of water interconnected to the cathode comprises bubbling air to the cathode. 
     
     
         18 . The system of  claim 16  wherein the source of oxygen and the source of water interconnected to the cathode comprises feeding humidified air to the cathode.