Removal of hydrogen sulfide from process streams

• US 10,232,311 B2
• Filed: 03/16/2016
• Issued: 03/19/2019
• Est. Priority Date: 03/16/2016
• Status: Active Grant

• Current Assignee: Guild Associates Incorporated
• Original Assignee: Guild Associates Incorporated
• Inventors: Rossin, Joe
• Primary Examiner(s): Berns, Daniel
• Application Number:
  US15/072,339
• Publication Number:
  US 20170266611A1
• Time in Patent Office: 1,098 Days
• Field of Search: None
• CPC Class Codes: B01D 2251/604 Hydroxides
• CPC Class Codes: B01D 2253/112 Metals or metal compounds not provided for in B01D2253/104 or B01D2253/106
• CPC Class Codes: B01D 2253/1124 Metal oxides
• CPC Class Codes: B01D 2256/245 Methane
• CPC Class Codes: B01D 2257/304 Hydrogen sulfide
• CPC Class Codes: B01D 2258/05 Biogas
• CPC Class Codes: B01D 51/10 Conditioning the gas to be cleaned
• CPC Class Codes: B01D 53/02 by adsorption, e.g. preparative gas chromatography solid sorbent compositions B01J20/00, preparation of inorganic compounds or elements C01
• CPC Class Codes: B01D 53/0454 Controlling adsorption controlling temperature swing adsorption B01D53/0462, controlling pressure swing adsorption B01D53/047
• CPC Class Codes: B01D 53/346 Controlling the process
• CPC Class Codes: B01D 53/52 Hydrogen sulfide
• CPC Class Codes: B01D 53/82 with stationary reactants
• CPC Class Codes: B01D 53/96 Regeneration, reactivation or recycling of reactants
• CPC Class Codes: Y02E 50/30 Fuel from waste, e.g. synthetic alcohol or diesel

Abstract

Disclosed are processes for removing H₂S from gas streams containing H₂S, the processes comprise contacting gas streams with a mixed metal oxy-hydroxide media comprising two or more metals selected from the group consisting of magnesium, chromium, manganese, iron, cobalt, zinc and copper. Also disclosed are processes for removing H₂S from gas streams containing H₂S, the processes comprise contacting the gas streams with a mixed metal oxy-hydroxide media comprising one or more metals selected from the group listed above plus one or more metals selected from the group consisting of aluminum, silicon, titanium and zirconium.

Claims

1. A process for removing H2S from a gas stream containing H2S, the process comprising

(i) assessing the O2/H2S molar ratio in the H2S containing gas stream to determine if the O2/H2S molar ratio is less than about 1.5;

(ii) mixing air or oxygen into the H2S containing gas stream at a rate to achieve an O2/H2S molar ratio equal to or greater than about 1.5 in the H2S containing gas stream, if the measured O2/H2S molar ratio is less than about 1.5;

(iii) assessing the relative humidity of the H2S containing gas stream;

(iv) adjusting the relative humidity of the H2S containing gas stream up, if the relative humidity is below 50%; and

subsequently

(v) contacting the H2S containing gas stream with a porous amorphous solid mixed metal oxy-hydroxide H2S removal media comprising zinc or iron plus one or more metals selected from the group consisting of aluminum, silicon, titanium and zirconium.

2. A process according to claim 1, wherein the H2S containing gas stream is contacted with the mixed metal oxy-hydroxide media at temperatures from about 0°

C. to about 45°

C.

3. A process according to claim 1, wherein O2 is added to the H2S containing gas stream at a rate to achieve an O2/H2S molar ratio greater than about 5 in the H2S containing gas stream.

4. A process according to claim 1, wherein the relative humidity of the H2S containing gas stream is adjusted to achieve a relative humidity equal to or greater than 50%.

5. A process according to claim 1, further comprising regenerating the mixed metal oxy-hydroxide media by first wetting the media to saturation with water, followed by exposing the media to flowing air at a temperature of about 25°

C. to about 150°

C.

6. A process according to claim 1, wherein the mixed metal oxy-hydroxide media comprises iron and silicon.

7. A process according to claim 1, wherein the mixed metal oxy-hydroxide media comprises aluminum.

8. A process for removing H2S from a gas stream containing H2S, the process comprising

(i) assessing O2/H2S molar ratio in the H2S containing gas stream to determine if the O2/H2S molar ratio is less than about 1.5 in the H2S containing gas stream;

(ii) mixing air or oxygen into the H2S containing gas stream if the O2/H2S molar ratio is less than about 1.5 to achieve an O2/H2S molar ratio equal to or greater than about 1.5 in the H2S containing gas stream,

(iii) contacting the H2S containing gas stream with a mixed metal oxy-hydroxide H2S removal media comprising zinc; and

(iv) regenerating the mixed metal oxy-hydroxide H2S removal media by first wetting the media to saturation with water, followed by exposing the media to flowing air having a relative humidity of 50% or greater at a temperature of about 25°

C. to about 150°

C.

9. A process according to claim 8, wherein the mixed metal oxy-hydroxide media has a H2S removal capacity equal to or greater than about 200 mg/g.

10. A process according to claim 8, wherein the mixed metal oxy-hydroxide H2S removal media comprises about 50% zinc.

11. A process according to claim 8, further comprising measuring the relative humidity of the H2S containing gas stream and adjusting the relative humidity of the H2S containing gas stream before contacting the gas stream with the mixed metal oxy-hydroxide H2S removal media.

12. A process according to claim 8, wherein the mixed metal oxy-hydroxide H2S removal media further comprises one or more metals selected from the group consisting of magnesium, chromium, manganese, iron, and cobalt, plus one or more metals selected from the group consisting of aluminum, silicon, titanium and zirconium.

13. A process according to claim 8, further comprising mixing air or oxygen into the H2S containing gas stream to achieve an O2/H2S molar ratio equal to or greater than about 5 in the H2S containing gas stream.

14. A process according to claim 8, further comprising pre-equilibrating the media under flowing, humid air at a target temperature prior to contacting the H2S containing gas stream with the media.

15. A process according to claim 8, wherein the mixed metal oxy-hydroxide H2S removal media further comprises iron.

16. A process according to claim 15, wherein the mixed metal oxy-hydroxide H2S removal media comprises about 50% zinc and about 25% iron.

17. A process according to claim 15, wherein the mixed metal oxy-hydroxide H2S removal media comprises at least about 25% iron.

18. A process according to claim 15, wherein the mixed metal oxy-hydroxide H2S removal media further comprises silicon.

19. A process according to claim 18, wherein the mixed metal oxy-hydroxide H2S removal media further comprises aluminum, titanium, or zirconium.

20. A process according to claim 18, wherein the mixed metal oxy-hydroxide H2S removal media comprises about 60% zinc, about 15% silicon and about 25% iron.