Hydrogen generator

• US 20010000380A1
• Filed: 12/05/2000
• Published: 04/26/2001
• Est. Priority Date: 11/06/1995
• Status: Active Grant

• Current Assignee: Robert E. Buxbaum
• Original Assignee: Robert E. Buxbaum
• Inventors: Buxbaum, Robert E.
• Granted Patent: US 6,461,408 B2
• Time in Patent Office: Days
• US Class Current: 95/55
• CPC Class Codes: B01D 2257/108 Hydrogen
• CPC Class Codes: B01D 2313/16 Specific vents
• CPC Class Codes: B01D 2313/22 Cooling or heating elements
• CPC Class Codes: B01D 2313/221 Heat exchangers
• CPC Class Codes: B01D 2313/42 Catalysts within the flow path
• CPC Class Codes: B01D 2321/2016 Static mixers; Turbulence generators
• CPC Class Codes: B01D 2325/10 Catalysts being present on the surface of the membrane or in the pores
• CPC Class Codes: B01D 2325/22 Thermal or heat-resistance properties
• CPC Class Codes: B01D 53/22 by diffusion manufacturing semi-permeable membranes B01D67/00; form, structure or properties of semi-permeable membranes B01D69/00; material for semi-permeable membranes B01D71/00
• CPC Class Codes: B01D 53/228 characterised by specific membranes
• CPC Class Codes: B01D 53/326 in electrochemical cells
• CPC Class Codes: B01D 63/024 with a single potted end
• CPC Class Codes: B01D 63/063 on the inner surface thereof
• CPC Class Codes: B01D 63/065 on the outer surface thereof
• CPC Class Codes: B01D 65/08 Prevention of membrane fouling or of concentration polarisation
• CPC Class Codes: B01D 67/0069 by deposition from the liquid phase, e.g. electrochemical deposition B01D67/0046 takes precedence
• CPC Class Codes: B01D 69/00 Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
• CPC Class Codes: B01D 71/022 Metals
• CPC Class Codes: B01D 71/02231 Palladium
• CPC Class Codes: B01J 19/2475 Membrane reactors
• CPC Class Codes: B01J 2208/00176 : outside the reactor
• CPC Class Codes: B01J 2208/00203 : Coils
• CPC Class Codes: B01J 2219/00063 : of the reactants
• CPC Class Codes: B01J 2219/00065 : Pressure measurement
• CPC Class Codes: B01J 2219/00078 : Fingers
• CPC Class Codes: B01J 2219/00081 : Tubes
• CPC Class Codes: B01J 2219/00083 : Coils
• CPC Class Codes: B01J 2219/0009 : Coils
• CPC Class Codes: B01J 2219/00094 : Jackets
• CPC Class Codes: B01J 2219/00132 : using electric heating or cooling elements
• CPC Class Codes: B01J 2219/00153 : Vacuum spaces
• CPC Class Codes: B01J 2219/00155 : using insulating materials or refractories
• CPC Class Codes: B01J 2219/00159 : controlling multiple zones along the direction of flow, e.g. pre-heating and after-cooling
• CPC Class Codes: B01J 8/009 : Membranes, e.g. feeding or removing reactants or products to or from the catalyst bed through a membrane
• CPC Class Codes: B01J 8/0285 : Heating or cooling the reactor for tubular reactors in furnaces B01J8/062
• CPC Class Codes: C01B 2203/041 : In-situ membrane purification during hydrogen production
• CPC Class Codes: C01B 2203/047 : the impurity being carbon monoxide
• CPC Class Codes: C01B 2203/0475 : the impurity being carbon dioxide
• CPC Class Codes: C01B 2203/048 : the impurity being an organic compound
• CPC Class Codes: C01B 2203/0495 : the impurity being water
• CPC Class Codes: C01B 3/323 : Catalytic reaction of gaseous or liquid organic compounds other than hydrocarbons with gasifying agents
• CPC Class Codes: C01B 3/501 : by diffusion
• CPC Class Codes: C01B 3/503 : characterised by the membrane
• CPC Class Codes: C01B 3/505 : Membranes containing palladium

Abstract

An apparatus for extracting a gas, in particular hydrogen, from a fluid stream utilizing a plate membrane flattened with a wave spring on the low pressure side of the membrane and a turbulence generator on the high pressure side. Alternately, the membrane is folded and wrapped against a central conduit within the membrane fold. Extraction membranes have a substrate layer of Ta—W, V—Co, V—Pd, V—Au, V—Cu, V—Al, Nb—Ag, Nb—Au, Nb—Pt, Nb—Pd, V—Ni—Co, V—Ni—Pd, V—Nb—Pt or V—Pd—Au alloy or combination thereof and a first layer affixed to the outer surface of the substrate towards a mixed gas flow which is composed of palladium, platinum, rhodium, or palladium alloys.

Claims

1. A membrane reactor comprising:

a chamber;

an inlet for introducing a mixed gas stream into said chamber;

a gas separator membrane having a surface in fluid communication with the mixed gas stream and an opposing surface in contact with a constituent gas of the mixed gas stream that has passed through said membrane, said membrane disposed within the dimensions of said chamber;

a catalyst disposed within said chamber that facilitates an exothermic chemical reaction of the mixed gas stream;

a flowing coolant in thermal contact with said chamber withdrawing thermal energy from said chamber;

a first outlet in fluid communication with the opposing surface of said membrane for removing said constituent gas that has passed through said membrane; and

a second outlet for removing a waste gas stream from said chamber.

2. The membrane reactor of

claim 1

further comprising an intercooler in fluid communication with said inlet for precooling the mixed gas stream prior to entering said chamber.

3. The membrane reactor of

claim 2

wherein said intercooler reduces the mixed gas stream to an exiting temperature of between 450°

C. and 130°

C.

4. The membrane reactor of

claim 1

wherein said membrane defines a wall of said chamber.

5. The membrane reactor of

claim 1

wherein the chemical reaction is a water-gas shift reaction.

6. The membrane reactor of

claim 1

wherein said catalyst is selected from the group consisting of oxides and sulfides of cobalt, nickel, copper, zinc, molybdenum, tungsten or combinations thereof or of the reduced metals themselves alone or in combination.

7. The membrane reactor of

claim 1

wherein said catalyst is pelletized.

8. The membrane reactor of

claim 1

wherein said catalyst is in physical contact with said chamber and in thermal contact with said coolant therethrough.

9. The membrane reactor of

claim 1

wherein said catalyst is in direct contact with said membrane.

10. The membrane reactor of

claim 1

wherein said membrane is of a shape selected from the group consisting of:

a cylinder, a plate, and a cylindrical coil.

11. The membrane reactor of

claim 1

wherein said membrane comprises a plurality of membranes.

12. The membrane reactor of

claim 1

wherein said membrane is a palladium alloy or a palladium-coated base metal.

13. The membrane reactor of

claim 12

wherein the palladium alloy is selected from the group consisting of palladium-copper and palladium-silver.

14. The membrane reactor of

claim 1

further comprising a structural membrane support bracing said membrane.

15. The membrane reactor of

claim 1

wherein said coolant is a gaseous fluid.

16. The membrane reactor of

claim 1

wherein said coolant is air.

17. The membrane reactor of

claim 1

further comprising a coolant outlet through which said coolant flows from said chamber.

18. The membrane reactor of

claim 17

wherein said coolant outlet is in fluid communication with a burner and said coolant is a combustible gaseous fluid.

19. The membrane reactor of

claim 18

wherein said burner is of a type selected from the group consisting of:

open flame and catalytic.

20. The membrane reactor of

claim 1

wherein said coolant flows concurrent with the mixed gas stream.

21. The membrane reactor of

claim 1

wherein said outlet for removing the remainder or raffinate stream is in fluid communication with a burner.

22. The membrane reactor of

claim 1

wherein said membrane is disposed generally vertically during operation.

23. The membrane reactor of

claim 1

further comprising a header in fluid communication with the opposing surface of said membrane and said outlet for removing said constituent gas.

24. A process for separating a gas component from a mixed gas stream comprising the steps of:

reacting a mixed gas stream exothermically with a catalyst in the presence of a membrane selective for passing the gas component; and

flowing coolant in thermal communication with the mixed gas stream.

25. The process of

claim 24

wherein said membrane has a pressure differential thereacross of between 1 and 500 psia and a mixed gas stream pressure of between 1 and 1000 psia.

26. The process of

claim 24

wherein reaction occurs at a steady state temperature of between 5°

C. and 650°

C.

27. The process of

claim 24

wherein the mixed gas stream comprises carbon monoxide and water vapor.

28. The process of

claim 24

wherein said catalyst is a water-gas shift catalyst.

29. The process of

claim 28

wherein said catalyst is pelletized.

30. The process of

claim 28

wherein said catalyst is in physical contact with said membrane.

31. A method of operating a water-gas shift membrane reactor comprising flowing a coolant in thermal communication with said reactor to withdraw heat generated by a water-gas shift reaction.

32. The method of

claim 31

further comprising driving said reaction by selectively removing a reaction product of said reaction.

33. The method of

claim 32

wherein the reaction product is hydrogen gas.