Integrated steam generator and superheater with process gas in ammonia synloop

Patent metadata

Field	Value
Publication number	US-12358803-B2
Application number	US-202117411413-A
Country	US
Kind code	B2
Filing date	Aug 25, 2021
Priority date	Aug 25, 2020
Publication date	Jul 15, 2025
Grant date	Jul 15, 2025

Abstract

An integrated steam generator/steam superheater apparatus is disclosed. The disclosed apparatus can be used in a process, such as an ammonia synthesis process, to cool an ammonia converter effluent process gas and to generate superheated steam. The integrated apparatus includes a steam superheater portion wherein hot process gas is used to generate superheated steam by heat transfer to saturated steam. The apparatus also includes a steam generator portion wherein the process gas is used to generate saturated steam by heat transfer to water. Both the superheater and the steam generator are integrated into a single unit, without intervening pluming, etc., thereby saving space and equipment.

First claim

What is claimed is:

1. An integrated steam generator/steam superheater apparatus comprising:
a steam superheater section integrated with a steam generator section, wherein:
the steam superheater section comprises a superheater chamber containing a first one or more heat exchange tubes and configured so that process gas within the superheater chamber superheats steam contained within the first one or more heat exchange tubes and then passes into the steam generator section, wherein
the steam generator section comprises a steam generator chamber containing a tube bank comprising a plurality of second heat exchange tubes and configured so that process gas from the steam superheater section passes into the plurality of second heat exchange tubes and generates steam by transferring heat to water contained within the steam generator chamber, and wherein
the apparatus is configured so that steam generated in the steam generator section is provided to the first one or more heat exchange tubes of the steam superheater section via an intervening steam drum.

2. The apparatus of claim 1 , wherein the tube bank comprises at least one hundred second heat exchange tubes.

3. The apparatus of claim 1 , further comprising a first manifold connecting the steam superheater section and the steam generator section.

4. The apparatus of claim 1 , further comprising a header and configured so that process gas contained within the plurality of second heat exchange tubes passes to the header via a second manifold.

5. The apparatus of claim 1 , wherein the steam drum is configured to accept boiler feed water (BFW) via a first inlet and to supply the BFW to the steam generator chamber via one or more down-comers.

6. The apparatus of claim 1 , wherein the steam drum is configured to receive steam generated in the steam generator chamber via one or more risers.

7. A method of generating superheated steam using an integrated steam generator/steam superheater apparatus comprising a steam superheater section integrated with a steam generator section, wherein
the steam superheater section comprises a superheater chamber containing a first one or more heat exchange tubes, and wherein
the steam generator section comprises a steam generator chamber containing a tube bank comprising a plurality of second heat exchange tubes, the method comprising:
receiving a process gas within the superheater chamber and allowing the process gas to superheat steam contained within the first one or more heat exchange tubes,
obtaining the superheated steam from the one or more heat exchange tubes,
passing the process gas from the superheater chamber into the plurality of second heat exchange tubes and allowing the process gas to generate steam in the steam generator chamber from boiler feed water (BFW) contained within the steam generator chamber, and
providing the steam generated within the steam generator chamber to the first one or more heat exchange tubes via an intervening steam drum.

8. The method of claim 7 , wherein the process gas is an effluent of an ammonia synthesis reaction.

9. The method of claim 8 , wherein the process gas comprises nitrogen, hydrogen, carbon monoxide, and ammonia.

10. The method of claim 7 , wherein the process gas is received within the superheater chamber has an initial temperature of 427 to 482° C.

11. The method of claim 7 , wherein the superheated steam has a temperature of 320 to 400° C.

12. The method of claim 7 , wherein the steam provided to the first one or more heat exchange tubes via an intervening steam drum has a temperature of 250 to 260° C.

13. The method of claim 7 , further comprising passing the process gas from the plurality of second heat exchange tubes to a header and obtaining the process gas from the header.

14. The method of claim 13 , wherein the process gas obtained from the header has a temperature of 370 to 300° C.

15. The method of claim 7 , further comprising providing BFW to the intervening steam drum.

16. The method of claim 15 , wherein the BFW provided to the intervening steam drum has a temperature of 200 to 226° C.

17. The method of claim 7 , further comprising providing BFW from the intervening steam drum to the steam generator chamber.

18. A method of generating ammonia, the method comprising:
reacting synthesis gas with nitrogen to produce an effluent process gas comprising ammonia and unreacted synthesis gas,
using an integrated steam generator/steam superheater apparatus to cool the process gas and to generate superheated steam,
further cooling the cooled process gas, and
isolating ammonia from the further cooled process gas, wherein
the integrated steam generator/steam superheater apparatus comprises a steam superheater section integrated with a steam generator section, wherein the steam superheater section comprises a superheater chamber containing a first one or more heat exchange tubes, and wherein the steam generator section comprises a steam generator chamber containing a tube bank comprising a plurality of second heat exchange tubes, and wherein

using the integrated steam generator/steam superheater apparatus to cool the process gas and to generate superheated steam, comprises:
receiving a process gas within the superheater chamber and allowing the process gas to superheat steam contained within the first one or more heat exchange tubes,
obtaining the superheated steam from the one or more heat exchange tubes,
passing the process gas from the superheater chamber into the plurality of second heat exchange tubes and allowing the process gas to generate steam in the steam generator chamber from boiler feed water (BFW) contained within the steam generator chamber, and
providing the steam generated within the steam generator chamber to the first one or more heat exchange tubes via an intervening steam drum.

19. The method of claim 18 , wherein the process gas is received within the superheater chamber has an initial temperature of 427 to 482° C.

20. The method of claim 18 , wherein the superheated steam has a temperature of 320 to 400° C.

Assignees

• Lin Xueqian
• Zhan Shiliang
• Kellogg Brown & Root Llc

Inventors

• Lin Xueqian
• Zhan Shiliang

Classifications

• F22G1/14

  using heat generated by chemical reactions · CPC title

• F22B31/00

  Modifications of boiler construction, or of tube systems, dependent on installation of combustion apparatus; Arrangements or dispositions of combustion apparatus · CPC title

• C01C1/04 Primary

  Preparation of ammonia by synthesis (preparation or purification of gas mixtures for ammonia synthesis C01B3/025) · CPC title

• F22G3/001

  Steam tube arrangements not dependent of location · CPC title

• F22G1/02

  with heat supply by hot flue gases from the furnace of the steam boiler · CPC title