Reactor and apparatus for hydrogen generation

• US 20050229490A1
• Filed: 04/19/2004
• Published: 10/20/2005
• Est. Priority Date: 04/19/2004
• Status: Abandoned Application

• Current Assignee: Texaco Development Corporation (Chevron Corp.), Texaco Incorporated (Chevron Corp.)
• Original Assignee: Texaco Development Corporation (Chevron Corp.), Texaco Incorporated (Chevron Corp.)
• Inventors: Stevens, James F., Rovner, Jerry M.
• Application Number:
  US10/827,580
• Publication Number:
  US 20050229490A1
• Time in Patent Office: Days
• US Class Current: 48/198.700
• CPC Class Codes: B01J 2208/00132 Tubes
• CPC Class Codes: B01J 2208/00141 Coils
• CPC Class Codes: B01J 2208/00309 with two or more reactions in heat exchange with each other, such as an endothermic reaction in heat exchange with an exothermic reaction
• CPC Class Codes: B01J 2208/00371 gaseous
• CPC Class Codes: B01J 2208/00398 inside the reactor bed
• CPC Class Codes: B01J 2208/00415 electric resistance heaters
• CPC Class Codes: B01J 2208/00495 using insulating materials or refractories
• CPC Class Codes: B01J 2208/00504 by means of a burner
• CPC Class Codes: B01J 2208/0053 Controlling multiple zones along the direction of flow, e.g. pre-heating and after-cooling
• CPC Class Codes: B01J 2208/00884 Means for supporting the bed of particles, e.g. grids, bars, perforated plates
• CPC Class Codes: B01J 2208/025 Two or more types of catalyst
• CPC Class Codes: B01J 2219/00006 Large-scale industrial plants
• CPC Class Codes: B01J 35/19 Catalysts containing parts with different compositions
• CPC Class Codes: B01J 8/025 in a cylindrical shaped bed
• CPC Class Codes: C01B 2203/0244 the reforming step being an autothermal reforming step, e.g. secondary reforming processes
• CPC Class Codes: C01B 2203/0283 containing a CO-shift step, i.e. a water gas shift step
• CPC Class Codes: C01B 2203/04 containing a purification step for the hydrogen or the synthesis gas
• CPC Class Codes: C01B 2203/041 In-situ membrane purification during hydrogen production
• CPC Class Codes: C01B 2203/0475 the impurity being carbon dioxide
• CPC Class Codes: C01B 2203/0844 the non-combustive exothermic reaction being another reforming reaction as defined in groups C01B2203/02 - C01B2203/0294
• CPC Class Codes: C01B 2203/127 : Catalytic desulfurisation
• CPC Class Codes: C01B 2203/142 : At least two reforming, decomposition or partial oxidation steps in series
• CPC Class Codes: C01B 2203/82 : Several process steps of C01B2203/02 - C01B2203/08 integrated into a single apparatus
• CPC Class Codes: C01B 2203/86 : Carbon dioxide sequestration
• CPC Class Codes: C01B 3/382 : Multi-step processes
• CPC Class Codes: Y02P 20/52 : using catalysts, e.g. selective catalysts
• CPC Class Codes: Y02P 30/00 : Technologies relating to oil refining and petrochemical industry

Abstract

Apparatus and methods for converting hydrocarbon fuels to hydrogen-rich reformate that incorporate a carbon dioxide fixing mechanism into the initial hydrocarbon conversion process. The mechanism utilizes a carbon dioxide fixing material within the reforming catalyst bed to remove carbon dioxide from the reformate product. The removal of carbon dioxide from the product stream shifts the reforming reaction equilibrium toward higher hydrocarbon conversion with only small amounts of carbon oxides produced. Fixed carbon dioxide may be released by heating the catalyst bed to a calcination temperature. Heat for releasing fixed carbon dioxide from the catalyst bed is generated internally within the reactor through oxidation. A non-uniform distribution of catalysts and carbon dioxide fixing material across catalyst bed can be utilized to achieve higher conversion rates of hydrocarbon to hydrogen-rich reformate.

Claims

1. A reforming reactor for producing a hydrogen reformate, the reactor comprising

a reactor vessel having an inlet for receiving a hydrocarbon fuel and an outlet for delivering a hydrogen-rich reformate;

a catalyst bed disposed within the reactor vessel, wherein the catalyst bed comprises a reforming catalyst and a carbon dioxide fixing material;

an oxidation zone disposed within the reactor vessel proximate the catalyst bed, the oxidation zone in fluid communication with the catalyst bed; and

a moderator inlet for introducing a temperature moderator into the oxidation zone.

2. The reactor of claim 1, wherein the catalyst bed further comprises a water gas shift catalyst.

3. The reactor of claim 1, further comprising an oxidant inlet for directing an oxidant into the oxidation zone.

4. The reactor of claim 1, further comprising catalyst bed support means for supporting the catalyst bed within the reactor vessel.

5. The reactor of claim 1, wherein the reactor vessel comprises a side wall comprising a refractory material.

6. The reactor of claim 1, wherein the catalyst bed has a non-uniform distribution of the reforming catalyst and carbon dioxide fixing material.

7. An apparatus for generating a hydrogen-rich reformate comprising:

a desulfurization unit for removing sulfur-containing compounds from a hydrocarbon fuel;

a reactor in fluid communication with the desulfurization unit for receiving the desulfurized hydrocarbon fuel and producing a hydrogen-rich reformate, the reactor comprising a reactor vessel having an inlet for receiving a hydrocarbon fuel and an outlet for delivering a hydrogen-rich reformate, a fixed catalyst bed disposed within the reactor vessel, wherein the catalyst bed comprises a reforming catalyst and a carbon dioxide fixing material, an oxidation zone disposed within the reactor vessel proximate the catalyst bed, the oxidation zone in fluid communication with the catalyst bed, and a moderator inlet for introducing a temperature moderator into the oxidation zone; and

a polishing unit in fluid communication with the reactor vessel, the polishing unit disposed downstream from the reactor vessel for removing one or more impurities from the hydrogen-rich reformate.

8. The apparatus of claim 7, wherein the polishing unit is selected from the group consisting of drying units, methanation reactors, selective oxidation reactors, pressure swing absorption units, temperature swing absorption units, membrane separators and combinations of thereof.

9. A reforming reactor for producing a hydrogen reformate, the reactor comprising

a reactor vessel having an inlet for receiving a hydrocarbon fuel and an outlet for delivering a hydrogen-rich reformate;

a fixed catalyst bed disposed within the reactor vessel, wherein the catalyst bed comprises a reforming catalyst and a carbon dioxide fixing material; and

an oxidation zone disposed within the reactor vessel downstream of the catalyst bed, the oxidation zone in fluid communication with the catalyst bed.

10. The reactor of claim 9, wherein the catalyst bed further comprises a water gas shift catalyst.

11. The reactor of claim 9, further comprising an oxidant inlet for directing an oxidant into the oxidation zone.

12. The reactor of claim 9, further comprising a moderator inlet for introducing a temperature moderator into the oxidation zone.

13. The reactor of claim 9, further comprising catalyst bed support means for supporting the catalyst bed within the reactor vessel.

14. The reactor of claim 9, wherein the reactor vessel comprises a side wall comprising a refractory material.

15. The reactor of claim 9, wherein the catalyst bed has a non-uniform distribution of the reforming catalyst and carbon dioxide fixing material.

16. The reactor of claim 9, further comprising heat exchanging means disposed within the reactor for exchanging heat between the catalyst bed and the oxidation zone.

17. An apparatus for generating a hydrogen-rich reformate comprising:

a desulfurization unit for removing sulfur-containing compounds from a hydrocarbon fuel;

a reactor in fluid communication with the desulfurization unit for receiving the desulfurized hydrocarbon fuel and producing a hydrogen-rich reformate, the reactor comprising a reactor vessel having an inlet for receiving a hydrocarbon fuel and an outlet for delivering a hydrogen-rich reformate, a fixed catalyst bed disposed within the reactor vessel, wherein the catalyst bed comprises a reforming catalyst and a carbon dioxide fixing material, and an oxidation zone disposed within the reactor vessel downstream of the catalyst bed, the oxidation zone in fluid communication with the catalyst bed; and

a polishing unit in fluid communication with the reactor vessel, the polishing unit disposed downstream from the reactor vessel for removing one or more impurities from the hydrogen-rich reformate.

18. The apparatus of claim 17, wherein the polishing unit is selected from the group consisting of drying units, methanation reactors, selective oxidation reactors, pressure swing absorption units, temperature swing absorption units, membrane separators and combinations thereof.

19. A method for producing a hydrogen-rich reformate in a reactor having a catalyst bed comprising a reforming catalyst and carbon dioxide fixing material, the method comprising the steps of:

converting a hydrocarbon fuel over the catalyst bed to a reformate comprising hydrogen and carbon dioxide, the carbon dioxide fixing material fixing at least a portion of the carbon dioxide in the reformate to provide a hydrogen-rich reformate and fixed carbon dioxide;

removing hydrogen-rich reformate from the catalyst bed;

oxidizing a hydrocarbon fuel with an oxidant within the reactor to produce heated oxidation products;

adjusting the temperature of the heated oxidation products with a flow of a temperature moderator; and

heating the carbon dioxide fixing material with the heated oxidation products to a temperature at which at least a portion of the fixed carbon dioxide is released to provide a carbon dioxide-laden gas and heated carbon dioxide fixing material.

20. The method of claim 19, further comprising the step of removing sulfur from the hydrocarbon fuel prior to converting the hydrocarbon fuel to a reformate.

21. The method of claim 19, wherein the hydrocarbon fuel is converted with steam over the catalyst bed to reformate.

22. The method of claim 19, wherein the hydrocarbon fuel is converted to a hydrogen-rich reformate at a steam reforming temperature between about 400°

C. and about 800°

C.

23. The method of claim 19, wherein the catalyst bed is purged with steam after removing the hydrogen-rich reformate from the catalyst bed.

24. The method of claim 19, wherein the temperature moderator is a fluid selected from the group consisting of steam, water, air, carbon dioxide, nitrogen and mixtures of thereof.

25. The method of claim 19, wherein the carbon dioxide fixing material is heated to a temperature between about 500°

C. and about 900°

C.

26. The method of claim 25, further comprising the step of interrupting the oxidation of the oxidant.

27. The method of claim 19, wherein the oxidant and the hydrocarbon fuel are oxidized non-catalytically.

28. The method of claim 19, further comprising the step of removing carbon dioxide-laden gas from the reactor vessel.

29. The method of claim 28, further comprising the step of purging the catalyst bed with steam after removing the carbon dioxide laden gas from the catalyst bed.

30. The method of claim 28, further comprising the step of resuming the conversion of the hydrocarbon fuel to reformate.

31. The method of claim 19, further comprising the step of hydrating the heated carbon dioxide fixing material with steam.

32. The method of claim 28, wherein the steam comprises a low temperature steam having a temperature below about 500°

C.

33. The method of claim 19, further comprising the step of directing the hydrogen-rich reformate to a polishing unit selected from the group consisting of drying units, methanation reactors, selective oxidation reactors, pressure swing absorption units, temperature swing absorption units, membrane separators and combinations thereof.