Adsorption-based Claus tail gas treatment

Patent metadata

Field	Value
Publication number	US-11945716-B2
Application number	US-202217945809-A
Country	US
Kind code	B2
Filing date	Sep 15, 2022
Priority date	Dec 15, 2021
Publication date	Apr 2, 2024
Grant date	Apr 2, 2024

Abstract

A method for sulfur recovery includes, in a hydrogenation reactor, converting sulfur-containing compounds in a Claus tail gas stream to hydrogen sulfide to produce a hydrogenated gas stream; feeding the hydrogenated gas stream to a quench tower to produce a quenched gas stream by condensing liquid water; feeding the quenched gas stream to a first stage adsorption vessel of a first stage adsorption unit to produce a first outlet gas stream by adsorbing water from the quenched gas stream; feeding the first outlet gas stream to a second stage adsorption vessel of a second stage adsorption unit to produce a second byproduct gas stream by adsorbing hydrogen sulfide from the first outlet gas stream; separating the second byproduct gas stream into a carbon dioxide stream and an enriched nitrogen stream; and regenerating the second stage adsorption vessel using the enriched nitrogen stream.

First claim

What is claimed is:

1. A method for sulfur recovery, the method comprising:
in a hydrogenation reactor, converting sulfur-containing compounds in a Claus tail gas stream to hydrogen sulfide to produce a hydrogenated gas stream comprising hydrogen sulfide, water, and at least one of carbon dioxide or nitrogen;
feeding the hydrogenated gas stream to a quench tower to produce a quenched gas stream by condensing liquid water into a water condensate stream;
feeding the quenched gas stream to a first stage adsorption vessel of a first stage adsorption unit to produce a first outlet gas stream by adsorbing water from the quenched gas stream;
feeding the first outlet gas stream to a second stage adsorption vessel of a second stage adsorption unit to produce a second byproduct gas stream by adsorbing hydrogen sulfide from the first outlet gas stream;
separating at least a portion of the second byproduct gas stream into a carbon dioxide stream and an enriched nitrogen stream; and
regenerating the second stage adsorption vessel by feeding a portion of the enriched nitrogen stream to the second stage adsorption vessel to produce a second outlet gas stream.

2. The method of claim 1 , comprising separating the first portion of the second byproduct gas stream into the carbon dioxide stream and the enriched nitrogen stream using cryogenic separation.

3. The method of claim 1 , comprising separating the first portion of the second byproduct gas stream into the carbon dioxide stream and the enriched nitrogen stream using a separation membrane.

4. The method of claim 3 , comprising applying vacuum to the separation membrane.

5. The method of claim 1 , comprising feeding the carbon dioxide stream to a thermal oxidizer.

6. The method of claim 5 , comprising feeding the carbon dioxide stream to the thermal oxidizer via an ejector.

7. The method of claim 1 , comprising regenerating the first stage adsorption vessel by feeding a first portion of the enriched nitrogen stream to the first stage adsorption vessel to produce a first byproduct gas stream by desorbing water.

8. The method of claim 7 , comprising joining the first byproduct gas stream with the hydrogenated gas stream to form a joined stream and feeding the joined stream to the quench tower.

9. The method of claim 1 , comprising heating the enriched nitrogen stream in a heat exchanger with heat from the hydrogenated gas stream.

10. The method of claim 1 , comprising pressurizing the quenched gas stream in a compressor; and cooling the pressurized quenched gas stream.

11. The method of claim 1 , comprising feeding the quenched gas stream to a collection drum to produce an adsorption feed by recovering liquid water via a second water condensate stream, in which the adsorption feed is fed to the first stage adsorption vessel.

12. The method of claim 1 , comprising feeding the water condensate stream to a sour water stripper.

13. The method of claim 1 , comprising feeding a second portion of the second byproduct gas stream to a thermal oxidizer.

14. The method of claim 1 , comprising feeding the second outlet gas to a reaction furnace.

15. A system for sulfur recovery from Claus tail gas, the system comprising:
a hydrogenation reactor configured to convert sulfur-containing compounds in a Claus tail gas stream to hydrogen sulfide to produce a hydrogenated gas stream;
a quench tower fluidically connected to the hydrogenation reactor and configured to receive the hydrogenated gas stream and produce a quenched gas stream by condensing liquid water into a water condensate stream;
a first stage adsorption unit comprising a first stage adsorption vessel that, during a first stage adsorption cycle, is fluidically connected to the quench tower and configured to receive the quenched gas stream and to produce a first outlet gas stream by adsorbing water from the quenched gas stream;
a second stage adsorption unit comprising a second stage adsorption vessel that, during a second stage adsorption cycle, is fluidically connected to the first stage adsorption vessel and configured to receive the first outlet gas stream and to produce a second byproduct gas stream by adsorbing hydrogen sulfide from the first outlet gas stream;
a carbon dioxide separation element configured to receive at least a portion of the second byproduct gas stream and to separate the portion of the second byproduct gas stream into a carbon dioxide stream and an enriched nitrogen stream;
in which the second stage adsorption vessel, during a second stage regeneration cycle, is configured to receive a portion of the enriched nitrogen stream.

16. The system of claim 15 , in which the carbon dioxide separation element comprises a separation membrane configured to separate the portion of the second byproduct gas stream into the carbon dioxide stream and the enriched nitrogen stream.

17. The system of claim 15 , in which the carbon dioxide separation element comprises a cryogenic separation element.

18. The system of claim 15 , comprising a thermal oxidizer configured to receive the carbon dioxide stream.

19. The system of claim 18 , comprising an ejector, in which the thermal oxidizer is configured to receive the carbon dioxide stream from the ejector.

20. The system of claim 15 , in which the first stage adsorption vessel, during a first stage regeneration cycle, is configured to receive a first portion of the enriched nitrogen stream and to produce a first byproduct gas stream by desorbing water.

21. The system of claim 15 , comprising a thermal oxidizer configured to receive a second portion of the second byproduct gas stream.

22. The system of claim 15 , comprising a reaction furnace fluidically connected to the second stage adsorption vessel and configured to receive a second outlet gas produced in the second stage adsorption unit during the second stage regeneration cycle.

23. The system of claim 15 , comprising a heat exchanger configured to cool the hydrogenated gas stream with heat from the enriched nitrogen stream.

24. The system of claim 15 , in which the first stage adsorption vessel comprises a hydrophilic molecular sieve.

25. The system of claim 15 , in which the second stage adsorption vessel comprises a Cu—Y type zeolite.

26. The system of claim 15 , in which the first stage adsorption unit comprises multiple first stage adsorption vessels fluidically connected in parallel, and in which the second stage adsorption unit comprises multiple second stage adsorption vessels fluidically connected in parallel.

27. A method for sulfur recovery, the method comprising:
in a hydrogenation reactor, converting sulfur-containing compounds in a Claus tail gas stream to hydrogen sulfide to produce a hydrogenated gas stream comprising hydrogen sulfide, water, and at least one of carbon dioxide or nitrogen;
feeding the hydrogenated gas stream to a quench tower to produce a quenched gas stream by condensing liquid water into a water condensate stream;
feeding the quenched gas stream to a first stage adsorption vessel of a first stage adsorption unit to produce a first outlet gas stream by adsorbing water from the quenched gas stream;
feeding the first outlet gas stream to a second stage adsorption vessel of a second stage adsorption unit to produce a second byproduct gas stream by adsorbing hydrogen sulfide from the first outlet gas stream; and
regenerating the second stage adsorption v

Assignees

• Saudi Arabian Oil Co

Inventors

• Lithoxoos Georgios
• Duval Sebastien A
• Othman Rashid M

Classifications

• C01B17/0447 Primary

  Separation of the obtained sulfur · CPC title

• B01D53/002

  by condensation · CPC title

• B01D2257/304

  Hydrogen sulfide · CPC title

• C01B17/0404

  by processes comprising a dry catalytic conversion of hydrogen sulfide-containing gases, e.g. the Claus process · CPC title

• C01B17/0408

  Pretreatment of the hydrogen sulfide containing gases · CPC title