Process and apparatus for the production of synthesis gas

• US 20060128818A1
• Filed: 02/24/2003
• Published: 06/15/2006
• Est. Priority Date: 02/25/2002
• Status: Active Grant

• Current Assignee: NiQuan Energy LLC
• Original Assignee: National Institute for Strategic Technology Acquisition and Commercialization
• Inventors: Peng, Xiang-Dong, Repasky, John, Nataraj, Shankar, Wang, Shoou-I
• Granted Patent: US 7,670,586 B2
• Time in Patent Office: Days
• US Class Current: 518/702
• CPC Class Codes: B01J 2208/00256 in a heat exchanger for the heat exchange medium separate from the reactor
• 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 8/0285 Heating or cooling the reactor for tubular reactors in furnaces B01J8/062
• CPC Class Codes: B01J 8/0488 the beds being placed in separate reactors
• 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 2203/0255 containing a non-catalytic partial oxidation step
• CPC Class Codes: C01B 2203/0261 containing a catalytic partial oxidation step [CPO]
• CPC Class Codes: C01B 2203/0283 containing a CO-shift step, i.e. a water gas shift step
• CPC Class Codes: C01B 2203/06 Integration with other chemical processes
• CPC Class Codes: C01B 2203/061 Methanol production
• CPC Class Codes: C01B 2203/062 Hydrocarbon production, e.g. Fischer-Tropsch process
• CPC Class Codes: C01B 2203/0838 by heat exchange with exothermic reactions, other than by combustion of fuel
• 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 2203/0877 by direct injection of fluid
• CPC Class Codes: C01B 2203/1241 Natural gas or methane
• CPC Class Codes: C01B 2203/127 Catalytic desulfurisation
• CPC Class Codes: C01B 2203/141 : At least two reforming, decomposition or partial oxidation steps in parallel
• CPC Class Codes: C01B 2203/143 : Three or more reforming, decomposition or partial oxidation steps in series
• CPC Class Codes: C01B 3/26 : using catalysts
• 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 3/386 : Catalytic partial combustion
• CPC Class Codes: C10J 2300/094 : Char
• CPC Class Codes: C10J 2300/0976 : as steam
• CPC Class Codes: C10J 2300/0986 : Catalysts
• CPC Class Codes: C10J 3/02 : Fixed-bed gasification of lump fuel
• CPC Class Codes: C10J 3/20 : Apparatus; Plants
• CPC Class Codes: C10K 3/026 : Increasing the carbon monoxide content, e.g. reverse water-gas shift [RWGS]
• CPC Class Codes: Y02E 60/32 : Hydrogen storage
• CPC Class Codes: Y02P 20/129 : Energy recovery, e.g. by cogeneration, H2recovery or pressure recovery turbines
• CPC Class Codes: Y02P 20/52 : using catalysts, e.g. selective catalysts

Abstract

Reactive diluent fluid (22) is introduced into a stream of synthesis gas (or “syngas”) produced in a heat-generating unit such as a partial oxidation (“POX”) reactor (12) to cool the syngas and form a mixture of cooled syngas and reactive diluent fluid. Carbon dioxide and/or carbon components and/or hydrogen in the mixture of cooled syngas and reactive diluent fluid is reacted (26) with at least a portion of the reactive diluent fluid in the mixture to produce carbon monoxide-enriched and/or solid carbon depleted syngas which is fed into a secondary reformer unit (30) such as an enhanced heat transfer reformer in a heat exchange reformer process. An advantage of the invention is that problems with the mechanical integrity of the secondary unit arising from the high temperature of the syngas from the heat-generating unit are avoided.

Claims

1. A process for the production of synthesis gas (“

syngas”

) comprising carbon monoxide and molecular hydrogen, said process comprising;

exothermically reacting hydrocarbon-containing fuel with an oxidant gas comprising molecular oxygen in a first reactor to produce an exothermically-generated syngas product;

combining a stream of reactive diluent fluid with a stream of said exothermically-generated syngas product to produce a reactive mixture;

reacting said reactive mixture in a second reactor to produce a reacted syngas product; and

endothermically reforming hydrocarbon-containing fuel gas with steam over a catalyst in a heat exchange reformer to produce a heat exchange-reformed syngas product,

wherein at least a portion of the heat required in the generation of said heat exchange-reformed syngas product is obtained by recovering heat from said reacted syngas product thereby cooling said reacted syngas.

2. The process as claimed in claim 1 wherein said heat exchange-reformed syngas product is combined with said reacted syngas product prior to heat recovery.

3. The process as claimed in claim 1 wherein the reactive diluent fluid controls the temperature of the exothermically-generated syngas product.

4. The process as claimed in claim 1, wherein the oxidant gas consists of molecular oxygen.

5. The process as claimed in claim 1, wherein the hydrocarbon fuel is reacted with the oxidant gas in the presence of water.

6. The process as claimed in claim 1, wherein the reactive mixture comprises carbon dioxide, at least a portion of which is reacted together with at least a portion of the molecular hydrogen in said reactive mixture over a catalyst in a reverse water gas shift reaction zone in the second reactor to produce a carbon monoxide-enriched syngas product.

7. The process as claimed in claim 1, wherein the reactive mixture comprises solid carbon particles, at least a portion of which is gasified by reaction with at least one other component of the reactive mixture in a gasification zone in the second reactor to produce a solid carbon-depleted syngas product.

8. The process as claimed in claim 1, wherein the reactive diluent fluid is a gas thereby cooling the exothermically-generated syngas product via sensible heat exchange.

9. The process as claimed in claim 1, wherein the reactive diluent fluid is a liquid thereby cooling the exothermically-generated syngas product via vaporisation and sensible heat exchange.

10. The process as claimed in claim 1, wherein the reactive diluent fluid is recovered and recycled from downstream processing of syngas.

11. The process as claimed in claim 1, wherein the reactive diluent fluid comprises carbon dioxide.

12. The process as claimed in claim 11 wherein the reactive diluent fluid comprises carbon dioxide separated and recycled from downstream syngas.

13. The process as claimed in claim 11 wherein the reactive diluent fluid comprises the products of a combustion process.

14. The process as claimed in claim 13 wherein the combustion products are selected from the group consisting of combustion furnace flue gases and gas turbine exhaust gas.

15. The process as claimed in claim 11 wherein the reactive diluent fluid comprises carbon dioxide imported from an external source.

16. The process as claimed in claim 1, wherein the reactive diluent fluid further comprises a component selected from the group consisting of methane and other hydrocarbon (s).

17. The process as claimed in claim 1, wherein the reactive diluent fluid comprises molecular hydrogen.

18. The process as claimed in claim 1, wherein the reactive diluent fluid comprises water.

19. The process as claimed in claim 18 wherein the water is in the form of liquid water.

20. The process as claimed in claim 18 wherein at least a portion of the water is in the form of steam.

21. The process as claimed in claim 1 wherein the heat exchange-reformed syngas product or a syngas mixture derived therefrom is used in a downstream conversion process to produce conversion products selected from the group consisting of hydrocarbon liquid fuels, methanol, DME and oxo-alcohols.

22. The process as claimed claim 1 further comprising combining a second diluent fluid with a syngas stream between the point at which the reactive diluent fluid is combined with said

exothermically-generated syngas product and the point at which heat is recovered from the reacted syngas product to adjust the temperature and/or change the composition of relevant syngas stream.

23. The process as claimed in claim 22 wherein the second diluent fluid is combined with the reactive mixture in any section of the second reactor.

24. The process as claimed in claim 22 wherein the second diluent fluid is combined with the reacted syngas product at any point between the second reactor and the heat exchange reformer or, where the heat exchange reformer is a shell and tube style reformer in which the endothermic reforming reaction occurs within the tubes and the reacted syngas product is introduced to the shell-side, in any section of the shell-side of the heat exchange reformer.

25. The process as claimed in claim 24 comprising combining molecular hydrogen as the second diluent fluid with the reacted syngas product to enhance the heat exchange efficiency inside the heat exchange reformer.

26. The process as claimed in claim 24 comprising combining water and/or steam as the second diluent with the reacted syngas product to reduce the amount of metal dusting inside the heat exchange reformer and/or to adjust the temperature of the reacted syngas product.

27. The process as claimed in claim 22 wherein the second diluent fluid is inert.

28. The process as claimed in claim 22 wherein the second diluent fluid is selected from the group consisting of water vapour, steam, liquid water, molecular hydrogen, carbon dioxide, methane, other hydrocarbons, off-gas from downstream processes, combustion furnace flue gases and gas turbine exhaust gas.

29. A process for the production of syngas comprising carbon monoxide and molecular hydrogen, said process comprising;

exothermically reacting hydrocarbon-containing fuel with an oxidant gas comprising molecular oxygen in a first reactor to produce an exothermically-generated syngas product;

cooling an effluent stream of said exothermically-generated syngas product by combining reactive diluent fluid-with said stream to produce a mixture comprising cooled exothermically-generated syngas product and reactive diluent fluid, said mixture further comprising at least one component selected from the group consisting of carbon dioxide and solid carbon particles;

said process further comprising;

reacting together carbon dioxide in said mixture with molecular hydrogen in said mixture over a catalyst in a second reactor to produce reacted syngas product that is enriched in carbon monoxide; and

/or gasifying solid carbon particles in said mixture with at least one other component in said mixture in a second reactor to produce reacted syngas product that is depleted in solid carbon.

31. A process as claimed in claim 29 further comprising endothermically reforming hydrocarbon-containing fuel gas with steam over a catalyst in a heat exchange reformer to produce heat exchange-reformed syngas product wherein at least a portion of the heat generated in the exothermic reaction producing said first syngas product is used to drive the endothermic reforming reaction.

30. (canceled)

32. (canceled)

33. Apparatus for the production of syngas comprising carbon monoxide and molecular hydrogen, said apparatus comprising:

a first reactor in which hydrocarbon-containing fuel is reacted exothermically with an oxidant gas comprising molecular oxygen to produce an exothermically-generated syngas product;

conduit means for removing an effluent stream of said exothermically-generated syngas product from the first reactor;

means for combining a stream of reactive diluent fluid with said effluent stream to produce a reactive mixture;

a second reactor in which said reactive mixture reacts to produce a reacted syngas product;

a heat exchange reformer in which hydrocarbon-containing fuel gas is reformed

endothermically with steam over a catalyst to produce a heat exchange-reformed

syngas product; and

conduit means for feeding a stream of reacted syngas product from the second reactor to the heat exchange reformer;

wherein at least a portion of the heat required in the generation of said heat exchange reformed syngas product is obtained by recovering heat from said reacted syngas product thereby cooling said reacted syngas product.

34. Apparatus as claimed in claim 33 wherein the first reactor is selected from the group consisting of a partial oxidation (“

POX”

) reactor, an autothermal reformer (“

ATR”

) and a catalytic partial oxidation (“

CPO”

) reactor.

35. Apparatus as claimed in claim 33 wherein the reactive mixture comprises carbon dioxide and the second reactor has a reverse water gas shift reaction zone in which at least a portion of the carbon dioxide and at least portion of the molecular hydrogen in said mixture are reacted together over a catalyst to produce a carbon monoxide-enriched syngas product.

36. Apparatus as claimed in claim 33 wherein the reactive mixture comprises solid carbon particles and the second reactor has a gasification reaction zone in which at least a portion of the solid carbon particles is gasified by reaction with at least one other component of the mixture to produce a solid carbon-depleted syngas product.

37. Apparatus as claimed in claim 33 wherein the heat exchange reformer is a shell and tube style reformer in which the endothermic reforming reaction occurs within the tubes and the reacted syngas product is introduced to the shell-side.

38. Apparatus as claimed claim 33 wherein the reformer is an enhanced heat transfer reformer (“

EHTR”

).

39. Apparatus as claimed in any of claim 33 further comprising means for combining a second diluent fluid with a syngas stream between the point at which the reactive diluent is combined with said exothermically-generated syngas product and the point at which heat is recovered from the reacted syngas product to adjust the temperature and/or change the composition of relevant syngas stream.

40. Apparatus for the production of syngas comprising carbon monoxide and molecular hydrogen, said apparatus comprising:

a first reactor in which hydrocarbon-containing fuel is reacted exothermically with an oxidant gas comprising molecular oxygen to produce an exothermically-generated syngas product;

a second reactor;

conduit means for feeding an effluent stream of said exothermically generated syngas product from the first reactor to the second reactor;

means for combining reactive diluent gas with said effluent stream to produce a mixture comprising cooled exothermically-generated syngas product and reactive diluent gas, said mixture further comprising at least one component selected from the group consisting of carbon dioxide and solid carbon particles;

said apparatus further comprising;

a reverse water gas shift reaction zone in which carbon dioxide in said mixture is reacted together with molecular hydrogen in said mixture over a catalyst in the second reactor to produce a reacted syngas product that is enriched in carbon monoxide; and

/or

a gasification reaction zone in which solid carbon particles in said mixture are gasified with at least one other component in said mixture in the second reactor to produce a reacted syngas product that is depleted in solid carbon.

41. Apparatus as claimed in claim 40 further comprising:

a heat exchange reformer in which hydrocarbon-containing fuel gas is reformed endothermically with steam over a catalyst to produce a heat exchange reformed syngas product;

conduit means for feeding reacted syngas product from the second reactor to the heat exchange reformer;

wherein at least a portion of the heat generated in the exothermic reaction producing said exothermically generated syngas product is used to drive the endothermic reforming reaction.

42. Apparatus as claimed in claim 40 wherein the first reactor is a partial oxidation (“

POX”

) reactor and the reformer is an EHTR.

43. (canceled)