Liquid anode electrochemical cell

Abstract

An electrochemical cell is provided which has a liquid anode. Preferably the liquid anode comprises molten salt and a fuel, which preferably has a significant elemental carbon content. The supply of fuel is preferably continuously replenished in the anode. Where the fuel contains or pyrolizes to elemental carbon, the reaction C+2O 2− →CO 2 +4e − may occur at the anode. The electrochemical cell preferably has a solid electrolyte, which may be yttrium stabilized zirconia (YSZ). The electrolyte is connected to a solid or liquid cathode, which is given a supply of an oxidizer such as air. An ion such as O 2− passes through the electrolyte. If O 2− passes through the electrolyte from the anode to the cathode, a possible reaction at the cathode may be O 2 +4e − →2O 2− . The electrochemical cell of the invention is preferably operated as a fuel cell, consuming fuel and producing electrical current.

1 . A fuel cell comprising 
 (a) a conductor serving as an anode current collector,    (b) a liquid anode,    (c) fuel distributed in the liquid anode,    (d) a solid oxygen ion-conductive electrolyte,    (e) a solid gas diffusion cathode,    (f) a first inlet for gaseous oxidizer,    (g) an outlet for gas evolved during the operation of the fuel cell.    
     
     
         2 . The fuel cell of  claim 1 , further comprising an anode recirculation system for recirculating the liquid anode.  
     
     
         3 . The fuel cell of  claim 1 , further comprising a fuel replenishment system for replenishing the supply of fuel in the liquid anode.  
     
     
         4 . The fuel cell of  claim 1 , further comprising a liquid anode cleanup system for removing from the liquid anode fuel oxidation products and impurities accumulated during cell operation.  
     
     
         5 . The fuel cell of  claim 1 , wherein the anode current collector forms a channel for the passage of the liquid anode.  
     
     
         6 . The fuel cell of  claim 1 , wherein the fuel is selected from one of carbon-containing materials, a metal, or hydrocarbons.  
     
     
         7 . The fuel cell of  claim 6 , wherein the fuel comprises tar, elemental carbon, coal, coke, biomass, carbon-containing waste, or aluminum.  
     
     
         8 . The fuel cell of  claim 1 , wherein the fuel is solid.  
     
     
         9 . The fuel cell of  claim 8 , wherein the fuel is in the form of solid particles.  
     
     
         10 . The fuel cell of  claim 1 , wherein the fuel is a liquid or molten hydrocarbon.  
     
     
         11 . The fuel cell of  claim 1 , further comprising a system for confining some or all of the gases evolved during the operation of the fuel cell so as to avoid their dispersal into the atmosphere.  
     
     
         12 . The fuel cell of  claim 1 , comprising a liquid anode outlet which is connected to a heat exchanger for utilizing the heat in liquid anode and gaseous fuel oxidation products leaving the fuel cell.  
     
     
         13 . The fuel cell of  claim 1 , further comprising a second outlet for used oxidizer gases, wherein the second outlet is connected to a heat exchanger for utilizing the heat in the used oxidizer gases leaving the fuel cell.  
     
     
         14 . The fuel cell of  claim 1 , wherein a power density of at least 50 mW/cm 2  can be obtained using coal and coke as a fuel.  
     
     
         15 . The fuel cell of  claim 1 , wherein a power density of at least 35 mW/cm 2  can be obtained using biomass, tar, carbon-containing waste, or a metal as a fuel.  
     
     
         16 . The fuel cell of  claim 1 , wherein a power density of at least 50 mW/cm 2  can be obtained using acetylene black as a fuel.  
     
     
         17 . The fuel cell of  claim 1 , wherein the liquid anode comprises molten salts, molten oxides, or mixtures thereof.  
     
     
         18 . The fuel cell of  claim 17 , wherein the liquid anode comprises alkali salts.  
     
     
         19 . The fuel cell of  claim 1 , wherein the liquid anode mixed with fuel is electronically conductive.  
     
     
         20 . The fuel cell of  claim 1 , wherein the liquid anode is oxygen ion conductive.  
     
     
         21 . A process for supplying electric current to a load having terminals, comprising the steps of: 
 (a) mixing fuel with a liquid anode,    (b) causing the liquid anode to contact a solid oxygen ion-conductive electrolyte,    (c) causing the fuel to react with oxygen ions entering the liquid anode from the electrolyte, releasing electrons,    (d) collecting released electrons via an anode current collector,    (e) supplying an oxidizer to a cathode connected to the solid electrolyte,    (f) causing a reduction reaction to occur at the cathode by supplying electrons via cathode current collector, thus producing oxygen ions which move through the electrolyte,    (g) electrically connecting the cathode and liquid anode current collectors to terminals of the load,    wherein the current supplied is sufficient to transfer energy to the load at a cell power density of 50 mW/cm 2 .