Solid multi-component membranes, electrochemical reactor components, electrochemical reactors and use of membranes, reactor components, and reactor for oxidation reactions

Abstract

Solid membranes comprising an intimate, gas-impervious, multi-phase mixture of an electronically-conductive material and an oxygen ion-conductive material and/or a mixed metal oxide of a perovskite structure are described. Electrochemical reactor components, such as reactor cells, and electrochemical reactors are also described for transporting oxygen from any oxygen-containing gas to any gas or mixture of gases that consume oxygen. The reactor cells generally comprise first and second zones separated by an element having a first surface capable of reducing oxygen to oxygen ions, a second surface capable of reacting oxygen ions with an oxygen-consuming gas, an electron-conductive path between the first and second surfaces and an oxygen ion-conductive path between the first and second surfaces. The element may further comprise (1) a porous substrate, (2) an electron-conductive metal, metal oxide or mixture thereof and/or (3) a catalyst. The reactor cell may further comprise a catalyst in the zone which comprises a passageway from an entrance end to an exit end of the element. Processes described which may be conducted with the disclosed reactor cells and reactors include, for example, the partial oxidation of methane to produce unsaturated compounds or synthesis gas, the partial oxidation of ethane, substitution of aromatic compounds, extraction of oxygen from oxygen-containing gases including oxidized gases, ammoxidation of methane, etc. The extraction of oxygen from oxidized gases may be used for flue or exhaust gas cleanup.

1 - 28 . (canceled)  
     
     
         29 . An electrochemical process for producing products which are liquid at ambient conditions from methane, natural gas or other light hydrocarbons which comprises: 
 (A) providing an electrochemical cell which comprises first and second zones separated by a solid gas-impervious membrane comprising a mixed metal oxide material of a perovskite structure having electron conductivity and oxygen ion conductivity,    (B) heating the electrochemical cell to a temperature of from about 1000° C. to about 1400° C.,    (C) passing an oxygen-containing gas in contact with the membrane in the first zone,    (D) passing methane or natural gas in contact with the membrane in the second-zone,    (E) recovering a substantially nitrogen-free synthesis gas comprising a mixture of hydrogen and carbon monoxide, from the second zone, and    (F) converting the recovered synthesis gas to products which are liquid at ambient conditions.    
     
     
         30 . The process of  claim 29  wherein (D) comprises passing a methane-steam mixture in contact with the membrane in the second zone.  
     
     
         31 . The process of  claim 29  where in the membrane comprises an electron-conductive mixed metal oxide of a perovskite structure which exhibits electron-conductivity and oxygen ion-conductivity.  
     
     
         32 . The process of  claim 29  wherein air is passed in contact with the membrane in the first zone.  
     
     
         33 . An electrochemical process for producing hydrogen cyanide from methane and ammonia which comprises: 
 (A) providing an electrochemical cell comprising first and second zones separated by a solid multi-component membrane comprising an intimate, gas-impervious, multi-phase mixture of an electronically-conductive phase and an oxygen ion-conductive phase,    (B) heating the electrochemical cell to a temperature of from about 100° C. to about 1400° C.,    (C) passing an oxygen-containing gas in contact with the membrane in the first zone, and    (D) passing methane and ammonia in contact with the membrane in the second zone.    
     
     
         34 . The electrochemical process of  claim 33  which further comprises: 
 (E) recovering hydrogen cyanide from the second zone.    
     
     
         35 . The electrochemical process of  claim 33  wherein the electronically-conductive phase comprises nickel, cobalt, copper, silver, gold, platinum, palladium, rhodium, ruthenium, bismuth oxides, tin-indium oxide mixtures, praseodymium-indium oxide mixtures, cerium-lanthanum oxide mixtures, niobium-titanium oxide mixtures, or electron-conductive mixed metal oxides of a perovskite structure, or mixtures thereof.  
     
     
         36 . The electrochemical process of  claim 33  wherein the electronically-conductive phase comprises a platinum or palladium metal.  
     
     
         37 . The electrochemical process of  claim 33  wherein the electronically-conductive phase comprises a praseodymium-doped indium oxide.  
     
     
         38 . An electrochemical process for producing hydrogen cyanide from methane and ammonia which comprises: 
 (A) providing an electrochemical cell which comprises first and second zones separated by a solid multi-component membrane comprising gas-impervious mixed oxide material of a perovskite structure having electron conductivity and oxygen ion conductivity,    (B) heating the electrochemical cell to a temperature of from about 1000° C. to about 1400° C.,    (C) passing air or oxygen in contact with the membrane in the first zone, and    (D) passing methane and ammonia in contact with the membrane in the second zone.    
     
     
         39 . The process of  claim 38  further comprising 
 (E) recovering hydrogen cyanide from the second zone.    
     
     
         40 . The process of  claim 38  wherein the mixed metal oxide material of a perovskite structure comprises a combination of elements selected from the group consisting of lanthanides, alkaline earth metals, Y, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, and Nb, oxides thereof, and mixtures of these metals and metal oxides.  
     
     
         41 . The process of  claim 38  wherein air is passed in contact with the membrane in the first zone.