Fuel cell system for transportation applications

• US 5,248,566 A
• Filed: 11/25/1991
• Issued: 09/28/1993
• Est. Priority Date: 11/25/1991
• Status: Expired due to Fees

• Current Assignee: United States Of America As Represented By The Department Of Energy
• Original Assignee: United States Department of Energy (Government of the United States of America)
• Inventors: Ahmed, Shabbir, Kumar, Romesh, Krumpelt, Michael, Myles, Kevin M.
• Primary Examiner(s): Willis, Jr., Prince
• Assistant Examiner(s): NUZZOLILLO, MARIA
• Application Number:
  US07/796,973
• Time in Patent Office: 673 Days
• Field of Search: 429/17, 429/19, 429/20, 180/65.3
• US Class Current: 429/424
• CPC Class Codes: H01M 8/0612 from carbon-containing material
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A propulsion system for a vehicle having pairs of front and rear wheels and a fuel tank. An electrically driven motor having an output shaft operatively connected to at least one of said pair of wheels is connected to a fuel cell having a positive electrode and a negative electrode separated by an electrolyte for producing dc power to operate the motor. A partial oxidation reformer is connected both to the fuel tank and to the fuel cell receives hydrogen-containing fuel from the fuel tank and water and air and for partially oxidizing and reforming the fuel with water and air in the presence of an oxidizing catalyst and a reforming catalyst to produce a hydrogen-containing gas. The hydrogen-containing gas is sent from the partial oxidation reformer to the fuel cell negative electrode while air is transported to the fuel cell positive electrode to produce dc power for operating the electric motor.

Claims

1. A propulsion system for a vehicle comprising a fuel cell having a positive electrode and a negative electrode separated by an electrolyte, means for delivering a source of oxygen to the positive electrode of said fuel cell, means for partially oxidizing and reforming hydrogen-containing fuel with water and air in an overall exothermic reaction to provide sufficient energy from the exothermic partial reaction to initiate and sustain the endothermic reformation reaction to produce a hydrogen-containing gas without an external thermal energy input, and means for delivering the hydrogen-containing gas to said negative electrode of said fuel cell, whereby delivery of said hydrogen-containing gas to said negative electrode and oxygen to said positive electrode of said fuel cell produces dc power for operating an electric motor in a vehicle.

2. The propulsion system of claim 1, wherein said fuel cell is a proton exchange membrane fuel cell or a phosphoric acid fuel cell.

3. The propulsion system of claim 1, wherein said means for partially oxidizing and reforming the fuel includes successive oxidation and reforming catalysts.

4. The propulsion system of claim 3, wherein the oxidation catalyst is one or more of NiO-ZrO₂, NiO-Al₂ O₃ -CaO and Cu-Pd-SiO₂.

5. The propulsion system of claim 3, wherein the reforming catalyst is one or more of CuO-ZnO-Al₂ O₃, NiO-Al₂ O₃ -MgO and Cu-SiO₂.

6. The propulsion system of claim 1, wherein the fuel is a gas or liquid hydrocarbon, alcohol, or alcohols, natural gas, or propane.

7. The propulsion system of claim 6, wherein the fuel is an alcohol or mixtures thereof, natural gas or propane.

8. The propulsion system of claim 7 wherein the fuel is methanol, ethanol or mixtures thereof, or natural gas.

9. The propulsion system of claim 1, and further comprising an afterburner unit for oxidizing any unreacted hydrogen leaving said negative electrode of said fuel cell.

10. The propulsion system of claim 3, and further including means for introducing a mixture of water and air and fuel to an oxidation catalyst and means for introducing a mixture of water and air and fuel to a reforming catalyst.

11. The propulsion system of claim 10, wherein the mixture introduced to the oxidation catalyst is different than the mixture introduced to the reforming catalyst.

12. A vehicle having pairs of front and rear wheels and a fuel tank, an electrically driven motor having an output shaft operatively connected to at least one of said pair of wheels, a fuel cell operatively connected to said motor and having a positive electrode and a negative electrode separated by an electrolyte for producing dc power to operate said electrically driven motor, a partial oxidation reformer operatively connected to said fuel tank and to said fuel cell and having means for receiving hydrogen-containing fuel from said fuel tank and water and air and for partially oxidizing and reforming the fuel with water and air in the presence of an oxidizing catalyst and a reforming catalyst in an overall exothermic reaction to provide sufficient energy from the exothermic partial oxidation reaction to initiate and sustain the endothermic reformation reaction to produce a hydrogen-containing gas without an external thermal energy input, means for transporting the hydrogen-containing gas from said partial oxidation reformer to said fuel cell negative electrode while air is transported to said fuel cell positive electrode to produce dc power for operating said electric motor and the pair of wheels operatively connected thereto.

13. The vehicle of claim 12, wherein said partial oxidation reformer has a longitudinal flow path and a mixture of water and air and fuel is introduced into said partial oxidation reformer at longitudinally spaced apart points of the flow path.

14. The vehicle of claim 13, wherein the oxidizing catalyst is one or more of NiO-ZrO₂ or NiO-Al₂ O₃ CaO or Cu-Pd-SiO₂.

15. The vehicle of claim 14, wherein the reforming catalyst is one or more of CuO-ZnO-Al₂ O₃, NiO-Al₂ O₃ -MgO and Cu-SiO₂.

16. The vehicle of claim 13, wherein the fuel cell is a proton exchange membrane cell or a phosphoric acid cell.

17. The vehicle of 13, wherein gas containing some hydrogen exits from said fuel cell negative electrode during production of dc power and further including a unit for oxidizing the hydrogen in the exit gas from said negative electrode to produce heat which may be used to heat or cool the vehicle.

18. A partial oxidation reformer comprising a longitudinally extending container having an inlet at one end thereof and an outlet at the other end thereof, a first zone holding an oxidation catalyst and a second zone longitudinally spaced from said first zone holding a reforming catalyst, a second inlet near said second zone, means for introducing a first mixture of water and air and fuel into said first zone, means for introducing a second mixture of water and air and fuel into said second zone, said first zone oxidation catalyst in contact with said first zone oxidation catalyst in contact with said first mixture producing a first product gas with some hydrogen and sufficient heat to initiate and maintain an endothermic reaction in said second zone to produce a product gas richer in hydrogen than said product from said first zone, whereby to provide oxidation and steam reforming reactions capable of being sustained without outside thermal energy.

19. The partial oxidation reformer of claim 18, wherein said first zone contains one or more of NiO-ZrO₂, NiO-Al₂ O₃ -CaO and Cu-Pd-SiO₂.

20. The partial oxidation reformer of claim 18, wherein said second zone contains one or more of CuO-ZnO-Al₂ O₃, NiO-Al₂ O₃ -MgO and Cu-SiO₂.

21. The partial oxidation reformer of claim 18 and further comprising a third zone holding an oxidation catalyst or a methanation catalyst.

22. The partial oxidation reformer of claim 21, wherein said oxidation catalyst in said third zone converts carbon monoxide present to carbon dioxide.

23. The partial oxidation reformer of claim 21, wherein said methanation catalyst in said third zone converts carbon monoxide present to methane.