AUTOTHERMAL REFORMER-REFORMING EXCHANGER ARRANGEMENT FOR HYDROGEN PRODUCTION

• US 20070217989A1
• Filed: 05/21/2007
• Published: 09/20/2007
• Est. Priority Date: 03/18/2003
• Status: Active Grant

• Current Assignee: Avinash Malhotra, James Gosnell
• Original Assignee: Avinash Malhotra, James Gosnell
• Inventors: MALHOTRA, AVINASH, Gosnell, James
• Granted Patent: US 7,550,215 B2
• Time in Patent Office: Days
• US Class Current: 423/437.100
• 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 2208/00504 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 2219/00006 Large-scale industrial plants
• CPC Class Codes: B01J 8/0488 the beds being placed in separate reactors
• CPC Class Codes: B01J 8/0496 Heating or cooling the reactor
• CPC Class Codes: B01J 8/065 Feeding reactive fluids
• CPC Class Codes: B01J 8/067 Heating or cooling the reactor B01J8/062 takes precedence
• CPC Class Codes: C01B 2203/0233 the reforming step being a steam reforming step
• 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 2203/0405 Purification by membrane separation
• CPC Class Codes: C01B 2203/042 Purification by adsorption on solids
• 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 2203/141 At least two reforming, decomposition or partial oxidation steps in parallel
• 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 3/382 Multi-step processes
• CPC Class Codes: C01B 3/384 the catalyst being continuously externally heated
• CPC Class Codes: C01B 3/48 followed by reaction of water vapour with carbon monoxide
• CPC Class Codes: H01M 8/0618 : Reforming processes, e.g. autothermal, partial oxidation or steam reforming
• CPC Class Codes: H01M 8/0668 : Removal of carbon monoxide or carbon dioxide
• CPC Class Codes: Y02E 60/50 : Fuel cells
• CPC Class Codes: Y02P 20/129 : Energy recovery, e.g. by cogeneration, H2recovery or pressure recovery turbines

Abstract

Low-energy, low-capital hydrogen production is disclosed. A reforming exchanger 14 is placed in parallel with an autothermal reformer (ATR) 10 to which are supplied a preheated steam-hydrocarbon mixture. An air-steam mixture is supplied to the burner/mixer of the ATR 10 to obtain a syngas effluent at 650°-1050° C. The effluent from the ATR is used to heat the reforming exchanger, and combined reformer effluent is shift converted and separated into a mixed gas stream and a hydrogen-rich product stream. High capital cost equipment such as steam-methane reformer and air separation plant are not required.

Claims

1. ) A process for reforming a hydrocarbon, comprising:

catalytically reforming a first portion of a hydrocarbon feed in the presence of steam and excess air in a first catalyst zone to produce a first effluent;

thermally reforming a second portion of the hydrocarbon feed in the presence of steam in a second catalyst zone to form a second effluent;

combining the first effluent and second effluent to form a mixed effluent;

indirectly exchanging heat from the mixed effluent to the second catalyst zone; and

shift converting the mixed effluent to obtain a carbon dioxide-rich gas.

2. ) The process of claim 1, further comprising separating the carbon dioxide-rich gas to provide a hydrogen-lean, mixed gas, and a hydrogen rich gas, wherein the hydrogen-lean mixed gas comprises nitrogen and carbon dioxide.

3. ) The process of claim 1, wherein the first effluent comprises at least 35 mole percent, dry basis, hydrogen;

and the second effluent comprises at least 70 mole percent, dry basis, hydrogen.

4. ) The process of claim 1, wherein the second catalyst zone comprises a plurality of tubes each containing a catalyst.

5. ) The process of claim 1, wherein thermally reforming the second portion of the hydrocarbon feed comprises passing the second portion of the hydrocarbon feed across or through the second catalyst zone, wherein the second catalyst zone is contained within a plurality of tubes.

6. ) The process of claim 1, wherein thermally reforming the second portion of the hydrocarbon feed comprises passing the second portion of the hydrocarbon feed across or through the second catalyst zone, wherein the second catalyst zone is disposed about a plurality of tubes.

7. ) The process of claim 1 wherein carbon dioxide-rich gas from the shift conversion comprises a molar ratio of hydrogen to nitrogen less than 3.

8. ) The process of claim 1 wherein the first portion of the hydrocarbon feed is about 55 to about 85 percent of the total hydrocarbon feed.

9. ) The process of claim 1 wherein the first portion of the hydrocarbon feed is about 60 to about 80 percent of the total hydrocarbon feed.

10. ) A process for generating an electrical current comprising the process of claim 1 and supplying the hydrogen-rich product gas to a fuel cell.

11. ) A hydrotreating process comprising the process of claim 1 and supplying the hydrogen-rich product gas to a hydrotreater.

25. ) The process of claim 1, further comprising supplying compressed air from a gas turbine to the first catalyst zone, and recovering heat from an exhaust gas from the turbine.

12. ) A system for reforming a hydrocarbon, comprising:

a first reactor comprising a burner section and a catalyst zone disposed beneath the burner section;

a second reactor comprising a plurality of tubes disposed therein, wherein a catalyst for reforming an hydrocarbon is located either in the tubes or outside the tubes; and

a shift converter.

13. ) The system of claim 12, further comprising a mixed gas separation unit.

14. ) The system of claim 12, wherein the shift converter operates at high temperature, medium temperature, low temperature, or any combination thereof.

15. ) The system of claim 13, wherein the mixed gas separation unit comprises a pressure swing adsorption unit.

16. ) A system for reforming a hydrocarbon, comprising:

means for catalytically reforming a first portion of a hydrocarbon feed in the presence of steam and excess air in a first catalyst zone to produce a first effluent;

means for thermally reforming a second portion of the hydrocarbon feed in the presence of steam in a second catalyst zone to form a second effluent, wherein the first effluent and second effluent are combined to provide a mixed effluent;

means for indirectly exchanging heat from the mixed effluent to the second catalyst zone; and

means for shift converting the mixed effluent to obtain a carbon dioxide-rich gas.

17. ) The system of claim 16, further comprising:

means for separating the carbon dioxide-rich gas to provide a hydrogen-lean, mixed gas, and a hydrogen rich gas, wherein the hydrogen-lean mixed gas comprises nitrogen and carbon dioxide.

18. ) A process for reforming a hydrocarbon, comprising:

catalytically reforming a first portion of a hydrocarbon feed in the presence of steam and excess air in a first catalyst zone to produce a first effluent;

thermally reforming a second portion of the hydrocarbon feed in the presence of steam in a second catalyst zone to form a second effluent;

combining the first effluent and second effluent to form a mixed effluent;

indirectly exchanging heat from the mixed effluent to the second catalyst zone;

shift converting the mixed effluent to obtain a carbon dioxide-rich gas;

separating the carbon dioxide-rich gas to provide a hydrogen-lean, mixed gas and a hydrogen rich gas, wherein the hydrogen-lean mixed gas comprises nitrogen and carbon dioxide; and

hydrotreating a hydrocarbon using the hydrogen rich gas.

19. ) The process of claim 18, wherein the first effluent comprises at least 35 mole percent, dry basis, hydrogen;

and the second effluent comprises at least 70 mole percent, dry basis, hydrogen.

20. ) The process of claim 18, wherein the second catalyst zone comprises a plurality of tubes each containing a catalyst.

21. ) The process of claim 18, wherein thermally reforming the second portion of the hydrocarbon feed comprises passing the second portion of the hydrocarbon feed across or through the second catalyst zone, wherein the second catalyst zone is contained within a plurality of tubes.

22. ) The process of claim 18, wherein thermally reforming the second portion of the hydrocarbon feed comprises passing the second portion of the hydrocarbon feed across or through the second catalyst zone, wherein the second catalyst zone is disposed about a plurality of tubes.

23. ) The process of claim 18, wherein the first portion of the hydrocarbon feed is about 55 to about 85 percent of the total hydrocarbon feed.

24. ) The process of claim 18, further comprising supplying compressed air from a gas turbine to the first catalyst zone, and recovering heat from an exhaust gas from the turbine.