Partial oxidation reformer-reforming exchanger arrangement for hydrogen production

• US 7,138,001 B2
• Filed: 03/15/2004
• Issued: 11/21/2006
• Est. Priority Date: 03/16/2003
• Status: Active Grant

• Current Assignee: Kellogg Brown & Root LLC (KBR Incorporated)
• Original Assignee: Kellogg Brown & Root LLC (KBR Incorporated)
• Inventors: Van Sickels, Martin J., Malhotra, Avinash, Mann, David P., Knez, Stanislaus A.
• Primary Examiner(s): Caldarola, Glenn
• Assistant Examiner(s): Patel, Vinit H.
• Application Number:
  US10/708,606
• Publication Number:
  US 20040177555A1
• Time in Patent Office: 981 Days
• Field of Search: 252/376, 165/158, 518/706, 518/703
• US Class Current: 48/198.3
• 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 2208/0053 Controlling multiple zones along the direction of flow, e.g. pre-heating and after-cooling
• CPC Class Codes: B01J 2219/00024 Revamping, retrofitting or modernisation of existing plants
• 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 2203/025 containing a partial oxidation step
• CPC Class Codes: C01B 2203/0283 containing a CO-shift step, i.e. a water gas shift step
• 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 2203/1241 Natural gas or methane
• 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 3/36 using oxygen or mixtures containing oxygen as gasifying agents
• 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: Y02P 20/10 Process efficiency

Abstract

Low-energy hydrogen production is disclosed. A reforming exchanger is placed in parallel with a partial oxidation reactor in a new hydrogen plant with improved efficiency and reduced steam export, or in an existing hydrogen plant where the hydrogen capacity can be increased by as much as 20–30 percent with reduced export of steam from the hydrogen plant.

Claims

1. A process for preparing syngas, comprising:

partially oxidizing a first hydrocarbon portion with oxygen in a partial oxidation reactor to produce a first reactor effluent;

cooling the first reactor effluent to a temperature from 650°

to 1000°

C., said cooling including direct heat exchange with water introduced into the first reactor effluent as a quench fluid;

supplying the cooled first reactor effluent to a reforming exchanger;

passing a second hydrocarbon portion with steam through a catalyst zone in the reforming exchanger to form a second reactor effluent, wherein the first and second hydrocarbon portions are supplied in a weight ratio of from 40;

60 to 60;

40;

discharging the second reactor effluent from the catalyst zone to form an admixture with the first reactor effluent;

passing the admixture across the catalyst zone in indirect heat exchange therewith to cool the admixture and heat the catalyst zone; and

collecting the cooled admixture from the reforming exchanger.

2. The process of claim 1, wherein the first reactor effluent cooling further comprises indirect heat exchange downstream from the direct heat exchange and upstream from the reforming exchanger.

3. The process of claim 2, wherein the first reactor effluent cooling by indirect heat exchange comprises heating the second hydrocarbon portion upstream from the catalyst zone in a cross exchange.

4. The process of claim 1, wherein the catalyst zone comprises catalyst tubes.

5. The process of claim 3, wherein the second hydrocarbon portion is supplied to a tube side of the reforming exchanger and passed through the catalyst tubes.

6. The process of claim 5, wherein the cooled first reactor effluent is supplied to a shell side inlet of the reforming exchanger.

7. The process of claim 6, wherein the shell side inlet is adjacent an outlet end of the catalyst tubes.

9. The process of claim 1 wherein the partial oxidation reactor is a non-catalytic reactor.

10. The process of claim 1 wherein the partial oxidation reactor is a free flow, unpacked, non-catalytic reactor.

11. The process of claim 1 wherein a temperature of the first reactor effluent is greater than 1000°

C.

17. The process of claim 1, wherein the partial oxidation reactor, catalytic reactor and the cooling of the first reactor effluent are operated to favor hydrogen production over carbon monoxide production.

18. The process of claim 1, further comprising shift converting the collected admixture to increase hydrogen content.

19. The process of claim 1, wherein the cooled first reactor effluent supplied to the reforming exchanger has a water content in excess of stoichiometric for shift conversion of CO.

8. An apparatus for producing syngas, comprising:

partial oxidation reactor means for partially oxidizing a first hydrocarbon portion with oxygen to produce a first reactor effluent;

means for cooling the first reactor effluent to a temperature from 650°

to 1000°

C., said cooling means including means for introducing water into the first reactor effluent as a quench fluid for direct heat exchange;

means for supplying the cooled first reactor effluent to a reforming exchanger;

means for passing a second hydrocarbon portion with steam through a catalyst zone in the reforming exchanger to form a second reactor effluent, wherein the first and second hydrocarbon portions are supplied in a weight ratio of from 40;

60 to 60;

40;

means for discharging the second reactor effluent from the catalyst zone to form an admixture with the first reactor effluent;

means for passing the admixture across the catalyst zone in indirect heat exchange therewith to cool the admixture and heat the catalyst zone;

means for collecting the cooled admixture from the reforming exchanger; and

means for shift converting the collected admixture to increase hydrogen content.

12. A process for preparing a hydrogen-rich syngas, comprising:

partially oxidizing a first hydrocarbon portion with oxygen in a non-catalytic partial oxidation reactor to produce a first reactor effluent having a temperature greater than 1000°

C.;

cooling the first reactor effluent to a temperature from 650°

to 1000°

C.;

said cooling including;

direct heat exchange with water introduced into the first reactor effluent as a quench fluid; and

indirect heat exchange in a cross exchange downstream from the direct heat exchange and upstream from the reforming exchanger comprising heating the second hydrocarbon portion upstream from the catalyst zone;

supplying the cooled first reactor effluent to a reforming exchanger;

passing a second hydrocarbon portion with steam through a catalyst zone in the reforming exchanger to form a second reactor effluent, wherein the first and second hydrocarbon portions are supplied in a weight ratio of from 40;

60 to 60;

40;

discharging the second reactor effluent from the catalyst zone to form an admixture with the first reactor effluent;

passing the admixture across the catalyst zone in indirect heat exchange therewith to cool the admixture and heat the catalyst zone; and

collecting the cooled admixture from the reforming exchanger.

13. The process of claim 12, wherein the catalyst zone comprises catalyst tubes.

14. The process of claim 13, wherein the second hydrocarbon portion is supplied to a tube side of the reforming exchanger and passed through the catalyst tubes.

15. The process of claim 14, wherein the cooled first reactor effluent is supplied to a shell side inlet of the reforming exchanger.

16. The process of claim 15, wherein the shell side inlet is adjacent an outlet end of the catalyst tubes.