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US 5,470,669 AGranted
Thermoelectrochemical system and method
AssigneeHughes Aircraft Company
InventorsFrank A. Ludwig, Carl W. Townsend, Bruce M. Eliash
Life of this patent
Estimating the term…
Abstract
A thermal electrochemical system in which an electrical current is generated between a cathode immersed in a concentrated aqueous solution of phosphoric acid and an anode immersed in a molten salt solution of ammonium phosphate and monohydric ammonium phosphate. Reactants consumed at the electrodes during the electrochemical reaction are thermochemically regenerated and recycled to the electrodes to provide continuous operation of the system.
Claims22
A thermoelectrochemical system for generating an electrical current comprising:
- a) an electrochemical cell having a cathode compartment and an anode compartment, said compartments having a common ion-permeable separation wall;
- b) a cathode and an anode located within their respective compartments, said cathode and anode being connectable externally of said cell for generation of said electrical current;
- c) a cathode solution comprising a concentrated aqueous solution of a chosen strong Bronsted acid located in said cathode compartment and in contact with said cathode wherein hydrogen ions are consumed at said cathode during generation of said electrical current and hydrogen gas and a first cell reaction product are generated;
- d) an anode solution comprising a chosen relatively low melting molten salt solution located in said anode compartment and in contact with said anode wherein the anion of said salt reacts with hydrogen gas to thereby reduce the hydrogen ion concentration in said anode compartment and to form a second cell reaction product, and wherein the cation of said salt is capable of being decomposed by heat to produce hydrogen ions;
- e) thermochemical regenerator means for thermally converting said first cell reaction product to said chosen acid and an intermediate regeneration product;
- f) means for transferring said cathode solution containing said first cell reaction product from said cathode compartment to said thermochemical regenerator means;
- g) cathode recycle means for transferring said chosen acid formed in said thermochemical regenerator means to said cathode compartment to replenish said chosen acid consumed during generation of said electrical current;
- h) means for combining said second cell reaction product from said anode compartment with said intermediate regeneration product from said thermochemical regenerator means to thereby form said molten salt solution;
- i) means for removing heat resulting from said combining in step "h";
- j) means for transferring said intermediate regeneration product produced in said thermochemical regenerator means to said means for combining;
- k) means for transferring anode solution containing said second cell reaction product to said means for combining;
- and
- l) anode recycle means for transferring said molten salt formed in said means for combining to said anode compartment to replenish said molten salt consumed during generation of said electrical current.
10 more elements
A thermoelectrochemical system for generating an electrical current comprising:
- a) an electrochemical cell having a cathode compartment and an anode compartment, said compartments having a common ion permeable separation wall;
- b) a cathode and an anode located within their respective compartments, said cathode and anode being connectable externally of said cell for generation of said electrical current;
- c) a cathode solution comprising a concentrated aqueous solution of phosphoric acid located in said cathode compartment and in contact with said cathode wherein hydrogen gas and dihydric ammonium phosphate are generated and phosphoric acid is consumed at said cathode during generation of said electrical current
- d) an anode solution comprising a molten salt solution of ammonium phosphate and monohydric ammonium phosphate or monohydric and dihydric ammonium phosphates located in said anode compartment and in contact with said anode wherein ammonium phosphate and hydrogen gas are consumed and monohydric ammonium phosphate or monohydric and dihydric ammonium phosphates are generated at said anode during generation of said electrical current;
- e) thermochemical regenerator means for thermally converting dihydric ammonium phosphate produced in said cathode compartment to phosphoric acid and ammonia;
- f) means for transferring cathode solution containing said dihydric ammonium phosphate from said cathode compartment to said thermochemical regenerator means;
- g) cathode recycle means for transferring phosphoric acid formed in said thermochemical regenerator means to said cathode compartment to replenish the phosphoric acid consumed during generation of said electrical current;
- h) means for removing heat from said phosphoric acid formed in said thermochemical regenerator means and transferring said heat to said transferred cathode solution;
- i) ammonium phosphate regenerator means for combining ammonia and monohydric ammonium phosphate to form ammonium phosphate and for condensing water vapor;
- j) means for removing heat resulting from said combining in step "i;"
- k) means for transferring ammonia and water produced in said thermochemical regenerator means to said ammonium phosphate regenerator means for combination and reaction with monohydric ammonium phosphate;
- l) means for transferring anode solution containing monohydric ammonium phosphate to said ammonium phosphate regenerator means for combination and reaction with ammonia to form said ammonium phosphate;
- m) anode recycle means for transferring the ammonium phosphate formed in said regenerator means to said anode compartment to replenish the ammonium phosphate consumed during generation of said electrical current.
10 more elements
A method for generating an electrical current between an anode and a cathode comprising the steps of:
- a) contacting a cathode with a cathode solution comprising a concentrated aqueous solution of phosphoric acid, said cathode and cathode solution being located in a cathode compartment, said cathode compartment having an ion permeable separation wall in common with an anode compartment;
- b) contacting an anode with an anode solution in said anode compartment, said anode solution comprising a molten salt solution of ammonium phosphate and monohydric ammonium phosphate or monohydric and dihydric ammonium phosphates, said anode and cathode being connectable for generation of said electrical current therebetween, and wherein hydrogen gas and dihydric ammonium phosphate are generated and phosphoric acid is consumed at said cathode during generation of said electrical current and wherein ammonium phosphate and hydrogen gas are consumed and monohydric ammonium phosphate or monohydric and dihydric ammonium phosphates are generated at said anode during generation of said electrical current;
- c) introducing hydrogen gas into said anode compartment;
- d) removing cathode solution containing dihydric ammonium phosphate from said cathode compartment;
- e) thermally converting the dihydric ammonium phosphate in the removed cathode solution to phosphoric acid, ammonia, and water;
- f) transferring heat from said thermally generated phosphoric acid to said removed cathode solution containing dihydric ammonium phosphate;
- g) transferring the thermally generated phosphoric acid to said cathode solution to replenish phosphoric acid consumed during generation of said electrical current;
- h) removing anode solution containing monohydric ammonium phosphate from said anode compartment;
- i) reacting the monohydric phosphate in the removed anode solution with the ammonia formed in step "e" to form ammonium phosphate;
- j) condensing and reacting the water formed in step "e" with monohydric ammonium phosphate in the removed anode solution to form ammonium phosphate solution;
- k) removing the heat resulting from the reacting of steps "i" and "j;"
- l) transferring the ammonium phosphate produced from the reaction of monohydric ammonium phosphate with ammonia to said anode compartment to replenish the ammonium phosphate consumed during generation of said electrical current.
9 more elements
Dependencies are inferred from the claim text.