Electrochemical cell for aluminum production using carbon monoxide

Abstract

The present technology discloses a method for producing aluminum from alumina in an electrolytic cell through the use of carbon monoxide as a partial or total reactant with aluminum oxide. The present technology also discloses the structure of an electrolytic cell configured to house this reaction.

We claim: 
     
         1 . An electrolytic cell for producing aluminum from alumina, the cell having an interior and an exterior, the cell comprising:
 an electrolyte solution contained within the interior of the cell;   an anode immersed in the electrolyte solution of the cell;   a gas inlet spanning from the exterior of the cell to the interior of the cell, the gas inlet having a first opening on the exterior of the cell and a second opening in the electrolyte solution on the interior of the cell;   a gas outlet spanning from the interior of the cell to the exterior of the cell, the gas outlet having a first opening in the electrolyte solution on the interior of the cell and a second opening on the exterior of the cell; and   a metal outlet spanning the interior of the cell to the exterior of the cell, the metal outlet having a first opening in the electrolyte solution on the interior of the cell and a second opening on the exterior of the cell.   
     
     
         2 . The electrolytic cell of  claim 1 , wherein the gas inlet is attached to an external supply of carbon monoxide. 
     
     
         3 . The electrolytic cell of  claim 1 , wherein the carbon monoxide exhausts into the cell near the anode. 
     
     
         4 . The electrolytic cell of  claim 1 , wherein the gas outlet is attached to a collection container configured to receive carbon dioxide exhausted from the cell. 
     
     
         5 . The electrolytic cell of  claim 1 , wherein the gas outlet is attached to a conduit configured to recycle the carbon dioxide to the external supply of carbon monoxide for the gas inlet. 
     
     
         6 . The electrolytic cell of  claim 1 , wherein the gas outlet is pressurized to exhaust the carbon dioxide from the cell. 
     
     
         7 . The electrolytic cell of  claim 1 , wherein the anode comprises carbon, graphite, coke, silicon carbide, boron carbide, niobium carbide, tungsten carbide, hafnium carbide, niobium carbide, tantalum carbide, zirconium carbide, molybdenum carbide, titanium carbide, silicon nitride, boron nitride, titanium diboride, or a combination of two or more thereof. 
     
     
         8 . The electrolytic cell of  claim 7 , wherein the anode comprises porous carbon, porous graphite, porous coke, porous silicon carbide, porous boron carbide, porous niobium carbide, porous tungsten carbide, porous hafnium carbide, porous niobium carbide, porous tantalum carbide, porous zirconium carbide, porous molybdenum carbide, porous titanium carbide, porous silicon nitride, porous boron nitride, porous titanium diboride, or a combination of two or more thereof, with an open porosity configured to allow gas to penetrate the anode. 
     
     
         9 . The electrolytic cell of  claim 1 , further comprising a cathode, the cathode comprising: carbon, graphite, coke, silicon carbide, boron carbide, niobium carbide, tungsten carbide, hafnium carbide, niobium carbide, tantalum carbide, zirconium carbide, molybdenum carbide, titanium carbide, silicon nitride, boron nitride, titanium diboride, or a combination of two or more thereof. 
     
     
         10 . The electrolytic cell of  claim 1 , wherein the gas inlet and the gas outlet comprise: carbon, graphite, coke, silicon carbide, boron carbide, niobium carbide, tungsten carbide, hafnium carbide, niobium carbide, tantalum carbide, zirconium carbide, molybdenum carbide, titanium carbide, silicon nitride, boron nitride, titanium diboride, or a combination of two or more thereof. 
     
     
         11 . The electrolytic cell of  claim 1 , wherein the metal outlet comprises: graphite, silicon carbide, boron carbide, niobium carbide, tungsten carbide, hafnium carbide, niobium carbide, tantalum carbide, zirconium carbide, molybdenum carbide, titanium carbide, silicon nitride, boron nitride, titanium diboride, or a combination of two or more thereof. 
     
     
         12 . A method for producing aluminum from alumina, comprising the steps of:
 (a) providing:
 an electrolytic cell having an interior and an exterior, the cell comprising:
 an electrolyte solution contained within the interior of the cell; 
 an anode immersed in the electrolyte solution of the cell; 
 a gas inlet spanning from the exterior of the cell to the interior of the cell, the gas inlet having a first opening on the exterior of the cell and a second opening in the electrolyte solution on the interior of the cell; 
 a gas outlet spanning from the interior of the cell to the exterior of the cell, the gas outlet having a first opening in the electrolyte solution on the interior of the cell and a second opening on the exterior of the cell; and 
 a metal outlet spanning the interior of the cell to the exterior of the cell, the metal outlet having a first opening in the electrolyte solution on the interior of the cell and a second opening on the exterior of the cell; 
 
   (b) providing carbon monoxide to the interior of the cell through the gas inlet;   (c) completing a reaction in the cell according to the following reaction:
   2Al 2 O 3  (in electrolyte)+6CO( g )=>4Al(1)+6CO 2 ( g ) 
   (d) plating liquid aluminum metal and exhausting the aluminum metal from the cell through the metal outlet;   (e) exhausting carbon dioxide through the cell through the gas outlet.   
     
     
         13 . The method of  claim 12 , wherein the anode comprises carbon. 
     
     
         14 . The method of  claim 13 , wherein said reaction results in a ratio of carbon anode material consumed to aluminum metal produced of less than 0.8. 
     
     
         15 . The method of  claim 14 , wherein said reaction results in a ratio of carbon anode material consumed to aluminum metal produced of less than 0.3. 
     
     
         16 . The method of  claim 12 , wherein the anode comprises porous carbon, porous graphite, porous coke, porous silicon carbide, porous boron carbide, porous niobium carbide, porous tungsten carbide, porous hafnium carbide, porous niobium carbide, porous tantalum carbide, porous zirconium carbide, porous molybdenum carbide, porous titanium carbide, porous silicon nitride, porous boron nitride, porous titanium diboride, or a combination of two or more thereof, with an open porosity configured to allow gas to penetrate the anode. 
     
     
         17 . The method of  claim 12 , the gas outlet is pressurized to exhaust the carbon dioxide from the cell. 
     
     
         18 . The method of  claim 12 , wherein the carbon dioxide exhausted from the cell is recycled to the gas inlet. 
     
     
         19 . The method of  claim 12 , wherein the reaction is completed at a temperature of at least 800° C. 
     
     
         20 . A process for manufacturing an electrolytic cell, the cell having an interior and an exterior, the cell comprising:
 an electrolyte solution contained within the interior of the cell;   an anode immersed in the electrolyte solution of the cell;   a gas inlet spanning from the exterior of the cell to the interior of the cell, the gas inlet having a first opening on the exterior of the cell and a second opening in the electrolyte solution on the interior of the cell;   a gas outlet spanning from the interior of the cell to the exterior of the cell, the gas outlet having a first opening in the electrolyte solution on the interior of the cell and a second opening on the exterior of the cell; and   a metal outlet spanning the interior of the cell to the exterior of the cell, the metal outlet having a first opening in the electrolyte solution on the interior of the cell and a second opening on the exterior of the cell.