Regeneration schemes for a two-stage adsorption process for Claus tail gas treatment

Patent metadata

Field	Value
Publication number	US-11760632-B2
Application number	US-201917788805-A
Country	US
Kind code	B2
Filing date	Dec 28, 2019
Priority date	Dec 28, 2019
Publication date	Sep 19, 2023
Grant date	Sep 19, 2023

Abstract

Embodiments of the disclosure provide a method and system for sulfur recovery. A Claus tail gas stream is fed to a hydrogenation reactor to produce a hydrogenated gas stream. The hydrogenated gas stream is fed to a quench tower to produce a quenched gas stream. The quenched gas stream is fed to a first stage adsorption vessel of first stage adsorption unit to produce a first outlet gas stream. The first outlet gas stream is fed to a second stage adsorption vessel of a second stage adsorption unit to produce a second byproduct gas stream. The first stage adsorption vessel is regenerated to produce a first byproduct gas stream. The second stage adsorption vessel is regenerated to produce a second outlet gas stream including hydrogen sulfide. Optionally, a portion of the second byproduct gas stream or nitrogen can be fed to the first stage adsorption vessel or the second stage adsorption vessel for regeneration. Optionally, a sales gas can be fed to the second stage adsorption vessel for regeneration. Optionally, vacuum can be applied to the first stage adsorption vessel or the second stage adsorption vessel for regeneration.

First claim

What is claimed is:

1 . A method for sulfur recovery, the method comprising the steps of:
feeding a tail gas stream to a hydrogenation reactor to produce a hydrogenated gas stream by converting sulfur-containing compounds to hydrogen sulfide, wherein the tail gas stream includes a Claus tail gas comprising the sulfur-containing compounds, wherein the hydrogenated gas stream comprises hydrogen sulfide, water, and at least one of: carbon dioxide and nitrogen, wherein the hydrogenated gas stream is in the absence of the sulfur-containing compounds other than hydrogen sulfide; feeding the hydrogenated gas stream to a quench tower to produce a quenched gas stream by condensing and recovering liquid water via a first water condensate stream, wherein the quenched gas stream comprises hydrogen sulfide and at least one of: water, carbon dioxide, and nitrogen; 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, wherein the first outlet gas stream comprises hydrogen sulfide and at least one of: carbon dioxide and nitrogen, wherein the first outlet gas stream is in the absence of water; 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, wherein the second byproduct gas stream is in the absence of hydrogen sulfide; regenerating the first stage adsorption vessel to produce a first byproduct gas stream by desorbing water, wherein the first byproduct gas stream comprises water; and regenerating the second stage adsorption vessel to produce a second outlet gas stream, wherein the second outlet gas stream comprises hydrogen sulfide.

2 . The method of claim 1 , further comprising the step of:
cooling the hydrogenated gas stream to a temperature ranging between 40° C. and 80° C.

3 . The method of claim 1 , further comprising the steps of:
pressurizing the quenched gas stream to a pressure ranging between 2 bar and 4 bar; and cooling the quenched gas stream to a temperature ranging between 10° C. and 30° C.

4 . The method of claim 3 , further comprising the step of:
feeding the quenched gas stream to a collection drum to produce an adsorption feed stream by recovering liquid water via a second water condensate stream, wherein the adsorption feed stream is fed to the first stage adsorption vessel.

5 . The method of claim 1 , wherein the first stage adsorption unit comprises at least three first stage adsorption vessels fluidly connected in parallel such that continuous flows of the first outlet gas stream and the first byproduct gas stream are provided by having one of the at least three first stage adsorption vessels in an adsorption cycle, one of the at least three first stage adsorption vessels in a regeneration cycle, and one of the at least three first stage adsorption vessels in a standby cycle.

6 . The method of claim 1 , wherein the first stage adsorption vessel comprises a first adsorbent, wherein the first adsorbent adsorbs water while passes hydrogen sulfide, carbon dioxide, and nitrogen to form the first outlet gas stream during an adsorption cycle.

7 . The method of claim 6 , wherein the first adsorbent comprises a hydrophilic 3 Å molecular sieve.

8 . The method of claim 1 , wherein the second stage adsorption unit comprises at least three second stage adsorption vessels fluidly connected in parallel such that continuous flows of the second outlet gas stream and the second byproduct gas stream are provided by having one of the at least three second stage adsorption vessels in an adsorption cycle, one of the at least three second stage adsorption vessels in a regeneration cycle, and one of the at least three second stage adsorption vessels in a standby cycle.

9 . The method of claim 1 , wherein the second stage adsorption vessel comprises a second adsorbent, wherein the second adsorbent adsorbs hydrogen sulfide while passes carbon dioxide and nitrogen to form the second byproduct stream during an adsorption cycle.

10 . The method of claim 9 , wherein the second adsorbent comprises a Cu-Y type zeolite.

11 . The method of claim 1 , further comprising the step of:
feeding the first byproduct gas stream to the quench tower.

12 . The method of claim 1 , wherein the regenerating the first stage adsorption vessel step includes feeding a portion of the second byproduct gas stream to the first stage adsorption vessel.

13 . The method of claim 1 , wherein the regenerating the first stage adsorption vessel step includes feeding nitrogen gas to the first stage adsorption vessel.

14 . The method of claim 1 , wherein the regenerating the first stage adsorption vessel step includes applying vacuum to the first stage adsorption vessel.

15 . The method of claim 1 , wherein the regenerating the second stage adsorption vessel step includes feeding a portion of the second byproduct gas stream to the second stage adsorption vessel.

16 . The method of claim 1 , wherein the regenerating the second stage adsorption vessel step includes feeding a sales gas to the second stage adsorption vessel.

17 . The method of claim 1 , wherein the regenerating the second stage adsorption vessel step includes feeding nitrogen gas to the second stage adsorption vessel.

18 . The method of claim 1 , wherein the regenerating the second stage adsorption vessel step includes applying vacuum to the second stage adsorption vessel.

19 . A Claus tail gas treatment system for sulfur recovery, the Claus tail gas treatment system comprising:
a hydrogenation reactor, the hydrogenation reactor configured to receive a Claus tail gas and to convert sulfur-containing compounds to hydrogen sulfide such that a hydrogenated gas stream is produced, wherein the Claus tail gas comprises the sulfur-containing compounds, wherein the hydrogenated gas stream comprises hydrogen sulfide, water, and at least one of: carbon dioxide and nitrogen, wherein the hydrogenated gas stream is in the absence of the sulfur-containing compounds other than hydrogen sulfide; a quench tower, the quench tower fluidly connected downstream of the hydrogenation reactor to receive the hydrogenated gas stream, the quench tower configured to condense and recover liquid water via a first water condensate stream and to produce a quenched gas stream, wherein the quenched gas stream comprises hydrogen sulfide and at least one of: water, carbon dioxide, and nitrogen; a first stage adsorption unit, the first stage adsorption unit comprising at least three first stage adsorption vessels fluidly connected in parallel, wherein, during a first stage adsorption cycle, one of the at least three first stage adsorption vessels is fluidly connected downstream of the quench tower to receive the quenched gas stream and adsorb water to produce a first outlet gas stream, wherein, during a first stage regeneration cycle, one of the at least three first stage adsorption vessels desorbs water to produce a first byproduct gas stream, wherein the first outlet gas stream comprises hydrogen sulfide and at least one of: carbon dioxide and nitrogen, wherein the first outlet gas stream is in the absence of water, wherein the first byproduct gas stream comprises water; and a second stage adsorption unit, the second stage adsorption unit comprising at least three second stage adsorption vessels fluidly connected in parallel, wherein, during a second stage adsorption cycle, one of the at least three

Assignees

• Saudi Arabian Oil Co

Inventors

• Lithoxoos Georgios
• Wang Yuguo
• Othman Rashid M
• Alami Ismail A
• O'Connell John P
• Duval Sebastien A

Classifications

• B01D53/04 Primary

  with stationary adsorbents {(B01D53/025 takes precedence)} · CPC title

• C01B17/0404 Primary

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

• B01D51/10

  Conditioning the gas to be cleaned · CPC title

• B01D53/261

  by adsorption · CPC title

• B01D53/52

  Hydrogen sulfide · CPC title