Removal of sulphur compounds from hydrocarbon streams using adsorbents and regeneration of the loaded adsorbents

• US 20060107832A1
• Filed: 10/29/2003
• Published: 05/25/2006
• Est. Priority Date: 10/29/2002
• Status: Active Grant

• Current Assignee: Shell Oil Company (Shell Plc)
• Original Assignee: Shell Oil Company (Shell Plc)
• Inventors: Last, Thijme, Van De Graaf, Jolinde Machteld
• Granted Patent: US 7,517,389 B2
• Time in Patent Office: Days
• US Class Current: 95/148
• CPC Class Codes: B01D 2253/108 Zeolites
• CPC Class Codes: B01D 2253/308 Pore size
• CPC Class Codes: B01D 2256/24 Hydrocarbons
• CPC Class Codes: B01D 2257/30 Sulfur compounds
• CPC Class Codes: B01D 2257/304 Hydrogen sulfide
• CPC Class Codes: B01D 2257/306 Organic sulfur compounds, e.g. mercaptans
• CPC Class Codes: B01D 2258/06 Polluted air
• CPC Class Codes: B01D 2259/40086 by using a purge gas B01D2259/4009 takes precedence
• CPC Class Codes: B01D 53/04 with stationary adsorbents B01D53/025 takes precedence
• CPC Class Codes: C10G 25/12 Recovery of used adsorbent
• CPC Class Codes: C10L 3/10 Working-up natural gas or synthetic natural gas
• CPC Class Codes: C10L 3/102 of acid contaminants
• CPC Class Codes: Y02C 20/40 of CO2

Abstract

The invention concerns a process for the removal of sulphur compounds from a hydrocarbon stream, especially a gaseous hydrocarbon gas stream, comprising said sulphur compounds, which process comprises contacting said gas stream with an adsorbent comprising a zeolite having a pore diameter of at least 5 Å to adsorb the sulphur compounds thereon, the adsorption process followed by a regeneration process of used, loaded adsorbent by contacting the said loaded adsorbent with a regeneration gas stream having a relative water humidity less than 100%, especially less than 80%. Suitably the regeneration is followed by a dry regeneration treatment. The invention further relates to a process for the regeneration of adsorbent comprising a zeolite having a pore diameter of at least 5 Å loaded with sulphur compounds by contacting the adsorbent with a regeneration gas stream having a relative water humidity less than 100%, especially less than 80%. Suitably the regeneration is followed by a dry regeneration treatment.

Claims

1. A process for the removal of sulfur compounds from a hydrocarbon stream, especially a gaseous hydrocarbon gas stream, comprising said sulfur compounds, which process comprises contacting said gas stream with an adsorbent comprising a zeolite having a pore diameter of at least 5 Å

to adsorb the sulfur compounds thereon, the adsorption process followed by a regeneration process in the presence of water of used, loaded adsorbent, by contacting the said loaded adsorbent with a regeneration gas stream having a relative humidity of at most 30%, wherein the regeneration gas is an inert gas or an inert gas mixture.

2. A process according to claim 1, in which the hydrocarbon stream is natural gas, associated gas, a natural gas liquids stream, a natural gas condensate stream or a refinery gas stream.

3. A process according to claim 2, in which the sulfur compounds are hydrogen sulfide, carbonyl sulfides, mercaptans, especially C₁-C₆ mercaptans, organic sulfides, especially di-C₁-C₄-alkyl sulphides, organic sulfides, especially di-C₁-C₄-alkyl disulfides, thiophene compounds, aromatic mercaptans, especially phenyl mercaptan, or mixtures thereof, more especially C₁-C₄ mercaptans, and the total amount of sulfur compounds contained in the hydrocarbon stream is up to 3 vol % based on total gas stream.

4. A process according to claim 3, in which the gas stream also comprises water, which is removed by adsorbing the water on a zeolite having a pore diameter of less than 5 Å

.

5. A process according to claim 4, in which the gas stream also comprises hydrogen sulfide and optionally carbon dioxide and, up to 2 vol % hydrogen sulfide, with the hydrogen sulfide and part of the carbon dioxide preferably being removed by means of washing the gas stream with a chemical solvent.

6. A process according to claim 5, in which the temperature of the zeolite adsorption process is between 10 and 60°

C., the pressure is between 10 and 150 bara, and the superficial gas velocity is between 0.03 and 0.6 m/s.

7. A process for the regeneration of an adsorbent comprising a zeolite having a pore diameter of at least 5 Å

and loaded with sulfur compounds by contacting the adsorbent with a regeneration gas stream having a relative water humidity less than 100.

8. A process according to claim 7, in which the adsorbent comprises zeolite dispersed in a binder.

9. A process according to claim 8, in which the adsorbent is in the form of at least two beds, one bed comprising zeolite having a pore diameter of 5 Å

, the second and, if present, further beds comprising a zeolite having a pore diameter of more than 5 Å

.

10. A process according to claim 9, in which the regeneration is carried out at a pressure between 1 and 150 bara, a temperature between 200 and 400°

C., and a superficial gas velocity of less than 0.20 m/s, the regeneration gas stream.

11. A process according to claim 10, in which the regeneration gas stream is a gas stream obtained by saturating the stream at a temperature below the regeneration temperature.

12. A process according to claim 11, in which the regeneration gas stream has a relative humidity between 0.1 and 30%.

13. A process for reducing the degradation of a sulfur loaded adsorbent, wherein the sulfur loaded adsorbent is regenerated in the presence of water by contacting the said loaded adsorbent with a regeneration gas stream having a relative humidity of at most 100%, wherein the regeneration gas is an inert gas or an inert gas mixture.

14. A process for the removal of sulfur compounds from a hydrocarbon stream, wherein said hydrocarbon stream contains a sulfur compound selected from the group consisting of hydrogen sulfide, carbonyl sulfide, mercaptans, organic sulfides, organic disulfides, thiophene compounds, aromatic mercaptans and mixtures thereof, said process comprises:

contacting said hydrocarbon stream with an adsorbent comprising a zeolite having a pore diameter of at least 5 Å

to absorb said sulfur compound thereon to thereby provide a sulfur loaded adsorbent; and

contacting said sulfur loaded adsorbent with a regeneration gas stream having a relative humidity of at most 30%, wherein the regeneration gas comprises an inert gas.

15. A process according to claim 14, wherein said hydrocarbon stream is selected from the group consisting of natural gas, associated gas, a natural gas liquid, natural gas condensate or refinery gas.

16. A process according to claim 15, wherein said mercaptans include C₁-C₆ mercaptans, said organic sulfides include di-C₁-C₄-alkyl sulfides, organic disulfides include di-C₁-C₄-alkyl disulfides, said aromatic mercaptans include phenyl mercaptan, and the total amount of said sulfur compounds contained in said hydrocarbon sstream is up to 3 vol % based on total gas stream.

17. A process according to claim 16, wherein said hydrocarbon stream is treated to remove water therefrom prior to contacting said hydrocarbon stream with said adsorbent contacting said hydrocarbon stream with a zeolite having a pore diameter of less than 5 Å

.

18. A process according to claim 17, in which said hydrocarbon stream prior to contacting with said adsorbent, comprises hydrogen sulfide in the range up to 2 vol % hydrogen sulfide, and a part thereof is removed by means of washing with a chemical solvent.

19. A process according to claim 18, in which the temperature of the step of contacting said hydrocarbon stream with said adsorbent is between 10 and 60°

C., the pressure is between 10 and 150 bara, and the superficial gas velocity is between 0.03 and 0.6 m/s.

20. A process for the regeneration of adsorbent comprising a zeolite having a pore diameter of at least 5 Å

and which is loaded with a sulfur compound by contacting the adsorbent with a regeneration gas stream having a relative water humidity of at least 0.1% and less than 100%.

21. A process according to claim 20, in which said adsorbent further comprises said zeolite dispersed in a binder.

22. A process according to claim 21, in which said adsorbent is contained in at least two beds, with one bed comprising zeolite having a pore diameter of 5 Å

, and with a second bed comprising a zeolite having a pore diameter of more than 5 Å

.

23. A process according to claim 22, in which the contacting step is carried out at a pressure between 1 and 150 bara, a temperature between 200 and 400°

C. and a superficial gas velocity of less than 0.20 m/s.

24. A process according to claim 23, in which said regeneration gas stream is a gas stream obtained by saturating the stream at a temperature below the regeneration temperature.

25. A process according to claim 24, in which said regeneration gas stream has a relative humidity between 0.1 and 30%.