Membrane catalytic heater

• US 20040209206A1
• Filed: 04/08/2004
• Published: 10/21/2004
• Est. Priority Date: 10/09/2001
• Status: Active Grant

• Current Assignee: Global Heating Technologies Gmbh
• Original Assignee: Vacca, Inc
• Inventors: Vaz, Heatcliff L., Hockaday, Robert G., Bradford, Zachary R., DeJohn, Marc D., Navas, Carlos J., Turner, Patrick S.
• Granted Patent: US 7,708,553 B2
• Time in Patent Office: Days
• US Class Current: 431/2
• CPC Class Codes: F23C 13/00 Apparatus in which combustion takes place in the presence of catalytic material in a fluidised bed of catalytic particles F23C10/01; radiant gas burners using catalysis for flameless combustion F23D14/18
• CPC Class Codes: F23C 13/02 characterised by arrangements for starting the operation, e.g. for heating the catalytic material to operating temperature
• CPC Class Codes: F23C 13/08 characterised by the catalytic material
• CPC Class Codes: F23C 2900/99001 Cold flame combustion or flameless oxidation processes
• CPC Class Codes: F23C 2900/9901 Combustion process using hydrogen, hydrogen peroxide water or brown gas as fuel
• CPC Class Codes: F23D 17/002 gaseous or liquid fuel
• CPC Class Codes: F23D 2900/03081 Catalytic wick burners
• CPC Class Codes: F23D 3/02 Wick burners
• CPC Class Codes: F23D 91/02 for use in particular heating operations
• CPC Class Codes: F23N 2237/12 catalytic burners
• CPC Class Codes: F23N 2237/14 burners with gasification or vaporizer elements
• CPC Class Codes: Y02E 20/34 Indirect CO2mitigation, i.e. by acting on non CO2directly related matters of the process, e.g. pre-heating or heat recovery

Abstract

This invention discloses a portable catalytic combustion heater. Fuel vapor and air are supplied to a catalyst which promotes the flameless combustion of the fuel, releasing heat. The fuel is supplied as a liquid, passes through a selectively permeable membrane such that fuel vapor exits the membrane and is fed to the catalyst. Additional features such as porous supports and means of enhancing and diminishing the catalytic rate of combustion and controlling the heat output are also shown. This invention can be used to heat apparel, blankets, food, dwellings, containers, machinery, insect attractants, humidifiers, and perfume generators.

Claims

1. A heat-generating device comprising a fuel source, a fuel delivery connected to the fuel source, a catalyst dispersed over a porous substrate, the catalyst being in diffusive contact with an oxidizing gas, and a selectively permeable membrane for selectively delivering fuel to the catalyst.

2. The device of claim 1, wherein the catalyst comprises a coating of a material, wherein the material permits fuel and oxidant to reach the catalyst and allows products to leave.

3. The device of claim 1, wherein the catalyst comprises a coating of a selectively permeable material.

4. The device of claim 3, wherein the selectively permeable material is selectively permeable to the fuel and the oxidizing gas.

5. The device of claim 1, wherein the catalyst comprises a coating of a selectively permeable material selected from the group consisting of rubbers, silicone rubbers, polymers, ionic polymers, Nafion, sulfonated butyl rubber, polystyrene, and combinations thereof.

6. The device of claim 1, wherein the porous substrate is selected from the group of materials consisting of polybenzoxazoles (PBOs), polybenzimidazoles (PBIs), para-aramids, polyimides, silicon carbide, alumina, carbon, fiber glass, zirconia, quartz and combinations thereof.

7. The device of claim 1, wherein the catalysts enable catalytic combustion of fuels.

8. The device of claim 7, wherein the catalysts are selected from the group consisting of highly dispersed platinum, palladium, nickel, ruthenium, iron, molybdenum, tungsten, tin, and combinations thereof.

9. The device of claim 1, wherein the fuel is a compound comprising hydrogen.

10. The device of claim 1, wherein the fuel is selected from the group consisting of methanol, formaldehyde, formic acid, 1,3,5-trioxane, di-methyl-ether, and combinations thereof.

11. The device of claim 2, further comprising enhancement of a performance of the catalyst with the catalyst coating.

12. The device of claim 11, wherein the enhancement of the performance comprises enhancing properties selected from the group consisting of surface protection, adhesion, filtration of external contaminates, varying affinity for fuel, varying affinity for oxidizing gas, diffusion rate limits of reactants to a surface of the catalyst, temperature dependency, regulation of diffusion rates of reactants to the surface of the catalyst, acidifying the surface, alkalizing the surface, and combinations thereof.

13. The device of claim 1, further comprising an upper temperature limit setting on a thermal output caused by boiling the fuel.

14. The device of claim 13, wherein the fuel is a liquid fuel, and wherein the fuel is removed from a catalytic reaction area by boiling.

15. The device of claim 14, further comprising valves, flow restrictions, or pressure reliefs for regulating a boiling temperature of the fuel.

16. The device of claim 1, further comprising optimal conditions in the device for catalytic combustion of vented gases from the selective membrane container.

17. The device of claim 1, further comprising regulation of fuel delivery rate with self pressurization of the fuel.

18. The device of claim 1, further comprising electrical temperature responsive devices for controlling fuel flow.

19. The device of claim 1, further comprising heat exchangers for transferring heat from the device to the fuel.

20. The device of claim 1, further comprising heat exchangers for heating air going to the catalyst.

21. The device of claim 1, further comprising heat pipes for transferring heat from the device, regulating temperatures in the device, and transferring heat to fluids and solids.

22. The device of claim 1, further comprising fuel additives for regulating temperatures and heat production rates.

23. The device of claim 1, further comprising mixtures of fuels for regulating temperatures and heat production rates.

24. The device of claim 1, further comprising thermoelectric devices for extracting electrical energy.

25. The device of claim 24, further comprising a delivery system for delivering electrical energy to batteries, motors, and electronic devices.

26. The device of claim 1, further comprising water produced from fuel combustion.

27. The device of claim 26, wherein the device is adapted for condensation of the water and comprising an exhaust for collecting the water after condensation.

28. The device of claim 1, wherein the selectively permeable membrane regulates delivery of oxidant to the catalyst.

29. The device of claim 1, further comprising a wick for distributing liquid fuel over a surface of selectively permeable membrane.

30. The device of claim 1, wherein the selectively permeable membrane is selectively permeable to gases and fuel boiling in the device and wherein the membrane uses the selective permeability to aspirate, circulate, or prevent motion of the fuel.

31. The device of claim 1, wherein the selectively permeable membranes are capable of changing diffusion rates with changes in temperature.

32. The device of claim 1, wherein the selectively permeable membranes change diffusion rates with temperature changes for regulating temperature of the device.

33. The device of claim 1, wherein the selectively permeable membranes change diffusion rates with temperature changes for regulating heat output.

34. The device of claim 1, wherein the selectively permeable membrane uses pressurization and subsequent effect on fuel containment at elevated temperatures for limiting delivery of the fuel or oxidizer to catalytic reaction sites in the device.

35. The device of claim 1, further comprising fans or pumps for regulating delivery of fuel or oxidant to an area of the catalyst.

36. The device of claim 1, further comprising fans or pumps for regulating heat exchange in an area of the catalyst.

37. The device of claim 1, further comprising an electric heater for initiating optimal conditions to operate the device.

38. The device of claim 1, further comprising an ignition system for igniting fuels and air and for heating the catalyst.

39. The device of claim 1, further comprising a proton-conducting material for supporting the catalyst, at least two electrodes on either side of the proton-conducting material, and a power source connected to the electrodes for providing a voltage.

40. The device of claim 39, further comprising influencing catalytic combustion rates by applying the voltage across the proton-conducting material.

41. The device of claim 1, further comprising a receiver for receiving the device.

42. The device of claim 41, wherein the receiver is selected from the group consisting of apparel, blankets, machinery, dwellings, shipping containers, storage containers, odorants, humidifiers, insect attractants, and combinations thereof.

43. The device of claim 1, further comprising means for pumping fuel towards an area of the catalyst.

44. The device of claim 1, further comprising a fuel ampoule having fuel-permeable walls for holding and releasing the fuel.

45. The device of claim 44, further comprising an impermeable material for holding the ampoule for preventing leakage of the fuel prior to use.

46. A heat generating apparatus comprising a heat generating device, fuel from a fuel supply, a selectively permeable membrane for selectively delivering the fuel, a catalyst and a means to deliver an oxidant or air.

47. The apparatus of claim 46, wherein the device is a portable catalytic combustion heater.

48. The apparatus of claim 47, further comprising a fuel and air delivery for supplying the fuel and the oxidant or air to the catalyst and for flameless combustion of the fuel for releasing heat.

49. The apparatus of claim 48, wherein the fuel is a liquid fuel passing through the selectively permeable membrane such that fuel vapor exits the membrane and is fed to the catalyst.

50. The apparatus of claim 46, further comprising porous supports for supporting the membrane.

51. The apparatus of claim 50, further comprising means for enhancing and diminishing a catalytic rate of combustion and for controlling a heat output.

52. The apparatus of claim 46, further comprising a receiver for receiving the device.

53. The apparatus of claim 52, wherein the receiver is selected from the group consisting of heat apparel, blankets, food, dwellings, containers, machinery, insect attractants, humidifiers, perfume generators, and combinations thereof.

54. The apparatus of claim 46, wherein the fuel is delivered through the selectively permeable membrane.

55. The apparatus of claim 54, wherein the selectively permeable membrane allows fuel to be delivered therethrough and prevents back dilution with byproducts of combustion.

56. The apparatus of claim 55, wherein the byproducts comprise water.

57. The apparatus of claim 54,.wherein the selectively permeable membrane allows oxygen therethrough and comprises reduced permeability to retain the fuel.

58. The apparatus of claim 54, wherein carbon dioxide and other gasses diffuse into the selectively permeable membrane and vent and circulate through the fuel with the fuel boiling in the device.

59. The apparatus of claim 46, further comprising a porous material substrate, wherein the catalyst is dispersed over the porous material substrate.

60. The apparatus of claim 59, wherein the selectively permeable membrane is a fuel and oxidizer permeable protective coating over the catalyst.

61. The apparatus of claim 59, wherein the selectively permeable membrane is a selectively permeable coating over the catalyst.

62. The apparatus of claim 59, further comprising a fuel retaining coating over the catalyst.

63. The apparatus of claim 59, further comprising a coating over the catalyst for enhancing a performance of the catalyst.

64. The apparatus of claim 59, further comprising a coating over the catalyst, wherein the coating is selected from the group consisting of electrolytic, acidic, basic substances, and combinations thereof.

65. The apparatus of claim 59, wherein vapors of the fuel depart from the selectively permeable membrane to reaction areas of the catalyst and form a thermostat providing an upper temperature limit for catalytic reactions.

66. The apparatus of claim 65, further comprising valves or flow restrictors for regulating boiling of the fuel and filling of the fuel and for regulating temperature and/or heating rates.

67. The apparatus of claim 59, further comprising fuel additives for adjusting catalytic burning temperatures.

68. The apparatus of claim 59, further comprising fuel additives.

69. The apparatus of claim 68, wherein the fuel additives include hydrocarbons with different boiling points.

70. The apparatus of claim 68, wherein the fuel additives include water.

71. The apparatus of claim 46, further comprising a heat exchanger formed by vaporization and condensation of the fuel.

72. The apparatus of claim 71, wherein the heat exchanger is a heat pipe.

73. The apparatus of claim 46, further comprising a temperature elevation formed by a boiling of the fuel for maintaining a reaction area temperature elevated.

74. The apparatus of claim 46, further comprising thermopiles for extracting electrical energy from the heating device and for transferring heat in the heating device.

75. The apparatus of claim 71, wherein the heat exchangers warm up air going to the heating device and exchange heat in the heating device.

76. The apparatus of claim 46, further comprising an exhaust and an extractor for extracting water formed from a condensation of the exhaust from the heating device.

77. The apparatus of claim 46, wherein the selectively permeable membrane regulates flow of air or oxidant to a catalytic reaction area.

78. The apparatus of claim 77, further comprising stoma for thermally regulating the air or oxidant to the reaction area.

79. The apparatus of claim 78, further comprising fans or pumps for regulating delivery of the fuel and/or air or oxidant to the reaction area.

80. The apparatus of claim 78, further comprising fans or pumps for regulating heat exchange in the reaction area.

81. The apparatus of claim 78, wherein the catalyst causes electrochemical catalysis for enhancing a performance of the catalyst.

82. The apparatus of claim 46, further comprising a power source for electrical heating to turn on the heating device.

83. The apparatus of claim 46, further comprising controls for pressurization of the fuel to control heat output.

84. The apparatus of claim 83, wherein the controls are passive mechanical controls.

85. The apparatus of claim 46, further comprising a wick for distributing fuel over the selectively permeable membrane.

86. The apparatus of claim 85, further comprising a receiver for holding the heating device.

87. The apparatus of claim 86, wherein the receiver is selected from the group consisting of apparel, blankets, machinery, dwellings, shipping containers, storage containers insect attractants, humidifiers, perfume generators, and combinations thereof.