Low pressure drop reforming exchanger

• US 8,216,531 B2
• Filed: 01/05/2005
• Issued: 07/10/2012
• Est. Priority Date: 07/18/2001
• Status: Expired due to Term

• Current Assignee: Kellogg Brown & Root LLC (KBR Incorporated)
• Original Assignee: Kellogg Brown & Root LLC (KBR Incorporated)
• Inventors: Burlingame, Robert, Hackemesser, Larry G., Czuppon, Thomas
• Primary Examiner(s): Handal, Kaity V.
• Application Number:
  US10/905,460
• Publication Number:
  US 20050086864A1
• Time in Patent Office: 2,743 Days
• Field of Search: 48/61, 481/279, 422/201, 422/198, 422196-197
• US Class Current: 422/653
• CPC Class Codes: B01J 19/30 Loose or shaped packing elements, e.g. Raschig rings or Berl saddles, for pouring into the apparatus for mass or heat transfer
• CPC Class Codes: B01J 2208/00221 comprising baffles for guiding the flow of the heat exchange medium
• 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 2208/00495 using insulating materials or refractories
• 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 2219/30223 Cylinder
• CPC Class Codes: B01J 2219/30242 Star
• CPC Class Codes: B01J 2219/32296 Honeycombs
• CPC Class Codes: B01J 23/755 Nickel
• CPC Class Codes: B01J 35/50 characterised by their shape or configuration
• CPC Class Codes: B01J 8/008 Details of the reactor or of the particulate material; Processes to increase or to retard the rate of reaction B01J8/0285, B01J8/067, B01J8/087, B01J8/1836 take precedence
• CPC Class Codes: B01J 8/0292 with stationary packing material in the bed, e.g. bricks, wire rings, baffles
• CPC Class Codes: B01J 8/067 Heating or cooling the reactor B01J8/062 takes precedence
• 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: Y02P 20/52 using catalysts, e.g. selective catalysts

Abstract

Disclosed are a syngas production process and a reforming exchanger 100. The process involves passing a first portion of hydrocarbon feed mixed with steam and oxidant through an autothermal catalytic steam reforming zone to form a first reformed gas of reduced hydrocarbon content, passing a second portion of the hydrocarbon feed mixed with steam through an endothermic catalytic steam reforming zone to form a second reformed gas of reduced hydrocarbon content, and mixing the first and second reformed gases and passing the resulting gas mixture through a heat exchange zone for cooling the gas mixture and thereby supplying heat to the endothermic catalytic steam reforming zone. The endothermic catalytic steam reforming zone and the heat exchange zone are respectively disposed tube side and shell side within a shell-and-tube reforming exchanger 100. The reforming exchanger 100 comprises a plurality of tubes 118 packed with low pressure drop catalyst-bearing monolithic structures 200 wherein an inside diameter of the tubes 118 is less than 4 times a maximum edge dimension of the catalyst structures 200.

Claims

1. An apparatus for reforming syngas, comprising:

an elongated shell having relatively high and low temperature ends;

a shell side fluid inlet adjacent the high temperature end;

a tube side fluid inlet adjacent the low temperature end;

a shell side fluid outlet fluidly isolated from the tube side fluid inlet by a tube sheet adjacent the low temperature end;

a tube bundle comprising a plurality of tubes and one or more longitudinally-spaced transverse baffle plates, wherein the tubes have an inlet end secured to the tube sheet and an outlet end adjacent the shell side fluid inlet; and

catalyst-bearing particles disposed within the tubes, wherein the catalyst-bearing particles comprise Raschig rings, ribbed rings, or a combination thereof, wherein the tubes have an inside diameter that is not more than 4 times a maximum edge dimension of the catalyst-bearing particles, and wherein the elongated shell contains no other catalyst other than the catalyst-bearing particles disposed within the tubes.

2. The apparatus of claim 1 wherein the tubes have an L_t/D_t ratio of at least 300 wherein L_t is taken as the length of the catalyst bearing extent of the tubes and D_t is the inside diameter of the tubes.

3. The apparatus of claim 1 wherein the catalyst-bearing particles comprise Raschig rings.

4. The apparatus of claim 3 wherein the inside diameter of the tubes is from 0.75 inches to 1.55 inches.

5. The apparatus of claim 3 wherein the Raschig rings have an outer diameter of 0.31 inches, an inner diameter of 0.125 inches, and a length of 0.31 inches.

6. The apparatus of claim 1, wherein a surface area of the catalyst-bearing particles for a given capacity is less than Raschig rings measuring 0.31 inches long, by 0.31 inches outside diameter, by 0.125 inches inside diameter in tubes having an inside diameter of 2 inches.

7. The apparatus of claim 6 wherein a catalyst volume of the catalyst-bearing particles for the given capacity is less than the Raschig rings in the 2 inch inside diameter tubes.

8. The apparatus of claim 1 wherein the catalyst-bearing particles are disposed within the tubes in a packed arrangement.

9. The apparatus of claim 1 wherein the tubes have an L_t/D_t ratio of at least 450 wherein L_t is taken as the length of the catalyst bearing extent of the tubes and D_t is the inside diameter of the tubes.

10. The apparatus of claim 1 wherein an inner surface of the elongated shell is cylindrical and has a constant diameter extending from the relatively high temperature end to the relatively low temperature end, and wherein the shell side fluid inlet, the tube side fluid inlet, and the shell side fluid outlet are all located between the relatively high temperature end and the relatively low temperature end.

11. The apparatus of claim 1 wherein the catalyst-bearing particles comprise ribbed rings.

12. The apparatus of claim 11 wherein the ribbed rings have an outer diameter of 0.2362 inches, an inner diameter of 0.0787 inches, a length of 0.2362 inches, and a fin height of 0.0787 inches, and wherein the length of the ribbed rings is equal to between ⅓

and ¼

the inside diameter of the tubes.

13. The apparatus of claim 1, wherein the tubes have an inside diameter that is not more than 3 times the maximum edge dimension of the catalyst-bearing particles.

14. The apparatus of claim 1 wherein the catalyst-bearing particles are disposed within the tubes in a packed arrangement, wherein the catalyst-bearing particles comprise Raschig rings, and wherein the tubes have an inside diameter that is not more than 3 times the maximum edge dimension of the catalyst-bearing particles.

15. The apparatus of claim 1 wherein the catalyst-bearing particles are disposed within the tubes in a packed arrangement, wherein the catalyst-bearing particles comprise Raschig rings, and wherein the tubes have an inside diameter that is not more than 3 times the maximum edge dimension of the catalyst-bearing particles, wherein the tubes have an L_t/D_t ratio of at least 300 wherein L_t is taken as the length of the catalyst bearing extent of the tubes and D_t is the inside diameter of the tubes, and wherein the inside diameter of the tubes is from 0.75 inches to 1.55 inches.

16. A reforming exchanger, comprising:

a shell having one or more catalyst-containing tubes disposed therein, wherein an inner surface of the shell is cylindrical and has a constant diameter extending from a first end to a second end thereof;

a first fluid inlet in fluid communication with the first end of the shell;

a second fluid inlet in fluid communication with the second end of the shell;

a fluid outlet in fluid communication with the second end of the shell, wherein the first fluid inlet, the second fluid inlet, and the fluid outlet are all located between the first end and the second end of the shell;

a tube sheet disposed within the second end of the shell, the tube sheet adapted to isolate the fluid outlet from the second fluid inlet; and

a tube bundle comprising the one or more catalyst-containing tubes and a plurality of longitudinally-spaced transverse baffle plates, wherein the tubes have an inlet secured to the tube sheet and an outlet adjacent the first fluid inlet, and wherein the tube bundle is disposed within the shell;

wherein the catalyst-containing tubes each comprise one or more catalyst-bearing particles disposed therein, wherein the catalyst-bearing particles are selected from the group consisting of Raschig rings, ribbed rings, or a combination thereof, wherein the tubes have an inside diameter that is not more than 4 times a maximum edge dimension of the catalyst-bearing particles, and wherein the shell contains no other catalyst other than the catalyst-bearing particles disposed within the tubes.

17. The exchanger of claim 16, wherein the tubes have an L_t/D_t ratio of at least 300 wherein L_t is taken as the length of the catalyst bearing extent of the tubes and D_t is the inside diameter of the tubes.

18. The exchanger of claim 16, wherein the inside diameter of the tubes is from 0.75 inches to 1.55 inches.

19. The exchanger of claim 16, wherein a surface area of the catalyst-bearing particles for a given capacity is less than Raschig rings measuring 0.31 inches long, by 0.31 inches outside diameter, by 0.125 inches inside diameter in tubes having an inside diameter of 2 inches.

20. The exchanger of claim 19, wherein a catalyst volume of the catalyst-bearing particles for the given capacity is less than the Raschig rings in the 2 inch inside diameter tubes.

21. The exchanger of claim 16 wherein the catalyst-bearing particles are disposed within the tubes in a packed arrangement, and wherein the catalyst-bearing particles consist essentially of the Raschig rings and have an outer diameter of 0.31 inches, an inner diameter of 0.125 inches, and a length of 0.31 inches.

22. The exchanger of claim 16 wherein at least a portion of the plurality of longitudinally-spaced transverse baffle plates define a transverse flow path across at least a portion of the tubes.

23. The exchanger of claim 16 wherein the tubes have an L_t/D_t ratio of at least 450 wherein L_t is taken as the length of the catalyst bearing extent of the tubes and D_t is the inside diameter of the tubes.

28. The apparatus of claim 22, wherein the elongated shell is a cylinder, and wherein the tubes have an inside diameter that is not more than 3 times the maximum edge dimension of the catalyst-bearing particles.

24. An apparatus for reforming syngas, comprising:

a shell having relatively high and low temperature ends;

a shell side fluid inlet adjacent the high temperature end;

a tube side fluid inlet adjacent the low temperature end;

a shell side fluid outlet fluidly isolated from the tube side fluid inlet by a tube sheet adjacent the low temperature end;

a tube bundle disposed within the shell, the tube bundle comprising a plurality of tubes and a plurality of longitudinally-spaced transverse baffle plates, wherein at least a portion of the plurality of longitudinally-spaced transverse baffle plates define a transverse flow path across at least a portion of the tubes, wherein the tubes have an inlet end secured to the tube sheet and an outlet end adjacent the shell side fluid inlet, and wherein the tubes have an L_t/D_t ratio of at least 300 wherein L_t is taken as the length of the catalyst bearing extent of the tubes and D_t is the inside diameter of the tubes; and

catalyst-bearing particles disposed within the tubes, wherein the catalyst-bearing particles comprise Raschig rings or ribbed rings, wherein the tubes have an inside diameter that is not more than 4 times a maximum edge dimension of the catalyst-bearing particles, and wherein the shell contains no other catalyst other than the catalyst-bearing particles disposed within the tubes.

25. The apparatus of claim 24 wherein the catalyst-bearing particles are disposed within the tubes in a packed arrangement.

26. The apparatus of claim 24 wherein an inner surface of the shell is cylindrical and has a constant diameter extending from the relatively high temperature end to the relatively low temperature end, and wherein the shell side fluid inlet, the tube side fluid inlet, and the shell side fluid outlet are all between the relatively high and low temperature ends.

27. The reforming exchanger of claim 24 wherein the catalyst-bearing particles comprise Raschig rings and have an outer diameter of 0.31 inches, an inner diameter of 0.125 inches, and a length of 0.31 inches.

29. The apparatus of claim 24 wherein the catalyst-bearing particles are disposed within the tubes in a packed arrangement, wherein the catalyst-bearing particles comprise Raschig rings, and wherein the tubes have an inside diameter that is not more than 3 times the maximum edge dimension of the catalyst-bearing particles.

30. The apparatus of claim 24 wherein the catalyst-bearing particles are disposed within the tubes in a packed arrangement, wherein the catalyst-bearing particles comprise Raschig rings, wherein the tubes have an inside diameter that is not more than 3 times the maximum edge dimension of the catalyst-bearing particles, wherein the tubes have an L_t/D_t ratio of at least 450 wherein L_t is taken as the length of the catalyst bearing extent of the tubes and D_t is the inside diameter of the tubes, and wherein the inside diameter of the tubes is from 0.75 inches to 1.55 inches.

31. An apparatus for reforming syngas, comprising:

an elongated shell having a first elliptical head disposed on a first end thereof, a second elliptical head disposed on a second end thereof, and a cylindrical inner surface having a constant diameter extending from the first end to the second end;

a tube sheet disposed within the elongated shell between the first and second ends thereof to provide a first internal volume toward the first end of the elongated shell and a second internal volume toward the second end of the elongated shell;

a fluid outlet and a first fluid inlet each in fluid communication with the first internal volume at locations intermediate the first and second ends of the elongated shell;

a second fluid inlet in fluid communication with the second internal volume at a location intermediate the first and second ends of the elongated shell;

a tube bundle comprising a plurality of tubes and a plurality of longitudinally-spaced transverse baffle plates, wherein the tubes have an inlet end secured to the tube sheet and in fluid communication with the second fluid inlet via the second internal volume and an outlet end adjacent the first fluid inlet and in fluid communication with the first internal volume, and wherein at least a portion of the plurality of longitudinally-spaced transverse baffle plates define a transverse flow path across at least a portion of the tubes; and

catalyst-bearing particles consisting of Raschig rings disposed within the tubes, wherein the tubes have an inside diameter that is not more than 4 times a maximum edge dimension of the catalyst-bearing particles, wherein the elongated shell contains no other catalyst other than the catalyst-bearing particles disposed within the tubes, and wherein the tubes have an L_t/D_t ratio of at least 450, where L_t is taken as the length of the catalyst bearing extent of the tubes and D_t is the inside diameter of the tubes.

32. The apparatus of claim 31 wherein the elongated shell is a cylinder, wherein the Raschig rings have an outer diameter of 0.31 inches, an inner diameter of 0.125 inches, and a length of 0.31 inches, wherein the Raschig rings are disposed within the tubes in a packed arrangement, and wherein the tubes have an inside diameter that is not more than 3 times a maximum edge dimension of the catalyst-bearing particles.

33. The apparatus of claim 31 wherein the catalyst-bearing particles are disposed within the tubes in a packed arrangement.

34. The apparatus of claim 31 wherein the catalyst-bearing particles are disposed within the tubes in a packed arrangement, and wherein the tubes have an inside diameter that is not more than 3 times the maximum edge dimension of the catalyst-bearing particles.