US4496534A
Expired / Lapsed
US
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Method for reconditioning bacteria-contaminated hydrogen sulfide removing systems
Assignee: Union Oil Company of California
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Filing: 1982-12-06
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Granted: 1985-01-29
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Expires: 2002-12-06
Abstract
Abstract A method is provided for reconditioning a hydrogen sulfide removal system, such as a Stretford process system in which elemental sulfur is formed, after the system has become contaminated with sulfur-feeding bacteria to an extent that operation thereof is substantially impaired. The method includes adding a bactericide to the washing solution employed in the system to destroy the bacteria and adding a surfactant to the solution to remove dead bacteria from the surfaces of particulate sulfur formed in the system so that the particles can agglomerate in the intended manner to enable sulfur removal from the solution.
Inventors
- 👤 Dennis D. Delaney
- 👤 Donald M. Fenton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:06
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/14; B01D53/1456; B01D53/1468; B01D53/1412; B01D53/1418; B01D53/1493; C; C01; C01B; C01B17/00; C01B17/02; C01B17/04; C01B17/05
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
262 words
A method for reconditioning a hydrogen sulfide gas removal system employing an aqueous washing solution in which hydrogen sulfide is reacted to form elemental sulfur and which has means for agglomerating said particles to enable sulfur removal from said solution for reuse, after said system and said solution have become contaminated with living, sulfur-feeding bacteria to an extent that normal operations of said sulfur removal means and of said solution regenerating means are substantially impaired, said reconditioning method comprising the steps of: (a) contacting said sulfur-feeding bacteria in said solution with a bactericidal agent to destroy substantially all of said sulfur-feeding bacteria; and (b) contacting said sulfur particles in said solution with a surfactant to remove a sufficient number of destroyed sulfur-feeding bacteria from surfaces of said sulfur particles to enable said particles to agglomerate in said sulfur removal means; wherein said bactericidal agent is sufficiently water soluble to allow the dissolving of a bacterially lethal concentration of said bactericidal agent into said washing solution, wherein said surfactant is nonionic and, at least, partially water soluble, and wherein both said bactericidal agent and said surfactant are substantially (1) stable at the conditions existant within said washing solution, (2) innocuous to the oxidation of hydrogen sulfide to sulfur, (3) innocuous to the regeneration of said washing solution with oxygen, (4) innocuous to the recovery of product sulfur and (5) chemically nonreactive or decomposable within the washing solution except in cases where essentially all products of reaction and/or decomposition are substantially innocuous to the environment and substantially innocuous to the hydrogen sulfide removal system.
Claim 2
Independent Claim
262 words
A method for reconditioning a hydrogen sulfide gas removal system employing an aqueous washing solution in which hydrogen sulfide is reacted to form elemental sulfur and which has means for agglomerating said particles to enable sulfur removal from said solution for reuse, after said system and said solution have become contaminated with living, sulfur-feeding bacteria to an extent that normal operations of said sulfur removal means and of said solution regenerating means are substantially impaired, said reconditioning method comprising the steps of: (a) contacting said sulfur-feeding bacteria in said solution with a bactericidal agent to destroy substantially all of said sulfur-feeding bacteria; and (b) contacting said sulfur particles in said solution with a surfactant to remove a sufficient number of destroyed sulfur-feeding bacteria from surfaces of said sulfur particles to enable said particles to agglomerate in said sulfur removal means; wherein said bactericidal agent is sufficiently water soluble to allow the dissolving of a bacterially lethal concentration of said bactericidal agent into said washing solution, wherein said surfactant is nonionic and, at least, partially water soluble, and wherein both said bactericidal agent and said surfactant are substantially (1) stable at the conditions existant within said washing solution, (2) innocuous to the oxidation of hydrogen sulfide to sulfur, (3) innocuous to the regeneration of said washing solution with oxygen, (4) innocuous to the recovery of product sulfur and (5) chemically nonreactive or decomposable within the washing solution except in cases where essentially all products of reaction and/or decomposition are substantially innocuous to the environment and substantially innocuous to the hydrogen sulfide removal system.
Claim 3
Dependent Claim
161 words
The reconditioning method defined in claim 1 wherein said surfactant comprises a compound selected from the group consisting of: (a) a polyoxyethylene condensate represented by the following general formula: R--O--(CH.sub.2 --CH.sub.2 --O).sub.n --H, wherein R is the residue of a fatty alcohol, acid, amide or amine having from about 10 to about 18 carbon atoms or an alkyl phenol having from about 10 to about 18 carbon atoms and where n is an integer of 1 or above; (b) a compound represented by the following general formula: ##STR4## wherein a, b, and c are integers between about 1 and about 100; and (c) an ethylene oxide adduct of acetylenic glycols represented by the general formula: ##STR5## wherein R 1 and R 4 are alkyl radicals containing from about 3 to about 10 carbon atoms, R 2 and R 3 are methyl or ethyl and x and y are integers having a sum in the range of about 3 to about 60.
Claim 4
Dependent Claim
18 words
The reconditioning method defined in claim 1 wherein said surfactant is a copolymer of polypropylene and polyethylene oxides.
Claim 5
Dependent Claim
37 words
The reconditioning method defined in claim 1 wherein said bactericidal agent is added to said solution in an amount providing a bacterial agent concentration level in said solution of between about 5 wppm and about 5,000 wppm.
Claim 6
Dependent Claim
37 words
The reconditioning method defined in claim 1 wherein said bactericidal agent is added to said solution in an amount providing a bactericidal agent concentration level in said solution of between about 10 wppm and about 100 wppm.
Claim 7
Dependent Claim
34 words
The reconditioning method defined in claim 1 wherein said surfactant is added to said solution in an amount providing a surfactant concentration in said solution of between about 10 vppm and about 100,000 vppm.
Claim 8
Dependent Claim
34 words
The reconditioning method defined in claim 1 wherein said surfactant is added to said solution in an amount providing a surfactant concentration in said solution of between about 1,000 vppm and about 5,000 vppm.
Claim 9
Dependent Claim
44 words
The reconditioning method defined in claim 1 further comprising the step, after said sulfur removing means has been reconditioned by said steps (a) and (b), of subsequently adding amounts of said bactericidal agent sufficient to prevent recontamination of said system by said sulfur-feeding bacteria.
Claim 10
Dependent Claim
42 words
The reconditioning method defined in claim 8 wherein said additional bactericidal agent is added to said solution at a rate so as to maintain a concentration of said bactericidal agent in said solution of between about 10 wppm and about 100 wppm.
Claim 11
Dependent Claim
22 words
The reconditioning method defined in claim 8 wherein said bactericidal agent concentration is maintained between about 10 wppm and about 50 wppm.
Claim 12
Independent Claim
201 words
A method for reconditioning a hydrogen sulfide gas removal system employing an aqueous washing solution in which hydrogen sulfide is reacted to form elemental sulfur and which has means for agglomerating said particles to enable sulfur removal from said solution and means for regenerating said solution for reuse, after said system and said solution have become contaminated with living, sulfur-feeding bacteria to an extent that normal operations of said sulfur removal means and of said solution regenerating means are substantially impaired, said reconditioning method comprising the steps of: (a) contacting said sulfur-feeding bacteria in said solution with a bactericidal agent to destroy substantially all of said sulfur-feeding bacteria; and (b) contacting said sulfur particles in said solution with a surfactant adaptable to said hydrogen sulfide gas removal system to remove a sufficient number of destroyed sulfur-feeding bacteria from surfaces of said sulfur particles to enable said particles to agglomerate in said sulfur removal means; wherein said bactericidal agent is comprised of a compound selected from the group consisting of tetrahydro-3,5 dimethyl-2H-1,3,5-thiadiazine-2-thione, 2-(4-thiazolyl) benzimidazole, p-chloro-m-cresol, sodium pyridinethione-N-oxide, sodium tetraborate pentahydrate, tributyltin oxide, tributyltin fluoride, bis tributyltin oxide, parachlorometacresol, methylenebisthiocyanate, 2,3,5,6 tetrachloro-4-(methyl sulfonyl)-pyridine, 3,4,5-trichloro-2,6-dicyanopyridine, sodium pyridinethione-N-oxide, alkyl dimethyl ethylbenzyl ammonium cyclohexylsulfamate and benzisothiazolone.
Claim 13
Independent Claim
201 words
A method for reconditioning a hydrogen sulfide gas removal system employing an aqueous washing solution in which hydrogen sulfide is reacted to form elemental sulfur and which has means for agglomerating said particles to enable sulfur removal from said solution and means for regenerating said solution for reuse, after said system and said solution have become contaminated with living, sulfur-feeding bacteria to an extent that normal operations of said sulfur removal means and of said solution regenerating means are substantially impaired, said reconditioning method comprising the steps of: (a) contacting said sulfur-feeding bacteria in said solution with a bactericidal agent to destroy substantially all of said sulfur-feeding bacteria; and (b) contacting said sulfur particles in said solution with a surfactant adaptable to said hydrogen sulfide gas removal system to remove a sufficient number of destroyed sulfur-feeding bacteria from surfaces of said sulfur particles to enable said particles to agglomerate in said sulfur removal means; wherein said bactericidal agent is comprised of a compound selected from the group consisting of tetrahydro-3,5 dimethyl-2H-1,3,5-thiadiazine-2-thione, 2-(4-thiazolyl) benzimidazole, p-chloro-m-cresol, sodium pyridinethione-N-oxide, sodium tetraborate pentahydrate, tributyltin oxide, tributyltin fluoride, bis tributyltin oxide, parachlorometacresol, methylenebisthiocyanate, 2,3,5,6 tetrachloro-4-(methyl sulfonyl)-pyridine, 3,4,5-trichloro-2,6-dicyanopyridine, sodium pyridinethione-N-oxide, alkyl dimethyl ethylbenzyl ammonium cyclohexylsulfamate and benzisothiazolone.
Claim 14
Dependent Claim
113 words
The reconditioning method defined in claim 11 wherein said bactericidal agent is sufficiently water soluble to allow the dissolving of a bacterially lethal concentration of said bactericidal agent into said washing solution, wherein said bactericidal agent is substantially (1) stable at the conditions existant within said washing solution, (2) innocuous to the oxidation of hydrogen sulfide to sulfur, (3) innocuous to the regeneration of said washing solution with oxygen, (4) innocuous to the recovery of product sulfur and (5) chemically nonreactive or decomposable within the washing solution except in cases where essentially all products of reaction and/or decomposition are substantially innocuous to the environment and substantially innocuous to the hydrogen sulfide removal system.
Claim 15
Dependent Claim
37 words
The reconditioning method defined in claim 11 wherein said bactericidal agent is added to said solution in an amount providing a bacterial agent concentration level in said solution of between about 5 wppm and about 5,000 wppm.
Claim 16
Dependent Claim
44 words
The reconditioning method defined in claim 11 further comprising the step, after said sulfur removing means has been reconditioned by said steps (a) and (b), of subsequently adding amounts of said bactericidal agent sufficient to prevent recontamination of said system by said sulfur-feeding bacteria.
Claim 17
Dependent Claim
42 words
The reconditioning method defined in claim 14 wherein said additional bactericidal agent is added to said solution at a rate so as to maintain a concentration of said bactericidal agent in said solution of between about 10 wppm and about 100 wppm.
Claim 18
Independent Claim
291 words
A method for reconditioning a hydrogen sulfide gas removal system employing an aqueous washing solution in which hydrogen sulfide is reacted to form elemental sulfur and which has means for agglomerating said particles to enable sulfur removal from said solution and means for regenerating said solution for reuse, after said system and said solution have become contaminated with living, sulfur-feeding bacteria to an extent that normal operations of said sulfur removal means and of said solution regenerating means are substantially impaired, said reconditioning method comprising the steps of: (a) contacting said sulfur-feeding bacteria in said solution with a bactericidal agent to destroy substantially all of said sulfur-feeding bacteria; and (b) contacting said sulfur particles in said solution with a surfactant adaptable to said hydrogen sulfide gas removal system to remove a sufficient number of destroyed sulfur-feeding bacteria from surfaces of said sulfur particles to enable said particles to agglomerate in said sulfur removal means; wherein said bactericidal agent is sufficiently water soluble to allow the dissolving of a bacterially lethal concentration of said bactericidal agent into said washing solution, wherein said bactericidal agent is substantially (1) stable at the conditions existant within said washing solution, (2) innocuous to the oxidation of hydrogen sulfide to sulfur, (3) innocuous to the regeneration of said washing solution with oxygen, (4) innocuous to the recovery of product sulfur and (5) chemically nonreactive or decomposable within the washing solution except in cases where essentially all products of reaction and/or decomposition are substantially innocuous to the environment and substantially innocuous to the hydrogen sulfide removal system, and wherein said bacteriacidal agent comprises a compound selected from the group consisting of the alkyl tin oxides, alkyl tin fluorides, thiones, thiocyanates, sulfonic-pyridines, cyano-pyridines, quaternary ammonium cations and amino alcohols.
Claim 19
Independent Claim
291 words
A method for reconditioning a hydrogen sulfide gas removal system employing an aqueous washing solution in which hydrogen sulfide is reacted to form elemental sulfur and which has means for agglomerating said particles to enable sulfur removal from said solution and means for regenerating said solution for reuse, after said system and said solution have become contaminated with living, sulfur-feeding bacteria to an extent that normal operations of said sulfur removal means and of said solution regenerating means are substantially impaired, said reconditioning method comprising the steps of: (a) contacting said sulfur-feeding bacteria in said solution with a bactericidal agent to destroy substantially all of said sulfur-feeding bacteria; and (b) contacting said sulfur particles in said solution with a surfactant adaptable to said hydrogen sulfide gas removal system to remove a sufficient number of destroyed sulfur-feeding bacteria from surfaces of said sulfur particles to enable said particles to agglomerate in said sulfur removal means; wherein said bactericidal agent is sufficiently water soluble to allow the dissolving of a bacterially lethal concentration of said bactericidal agent into said washing solution, wherein said bactericidal agent is substantially (1) stable at the conditions existant within said washing solution, (2) innocuous to the oxidation of hydrogen sulfide to sulfur, (3) innocuous to the regeneration of said washing solution with oxygen, (4) innocuous to the recovery of product sulfur and (5) chemically nonreactive or decomposable within the washing solution except in cases where essentially all products of reaction and/or decomposition are substantially innocuous to the environment and substantially innocuous to the hydrogen sulfide removal system, and wherein said bacteriacidal agent comprises a compound selected from the group consisting of the alkyl tin oxides, alkyl tin fluorides, thiones, thiocyanates, sulfonic-pyridines, cyano-pyridines, quaternary ammonium cations and amino alcohols.
Claim 20
Dependent Claim
37 words
The reconditioning method defined in claim 16 wherein said bactericidal agent is added to said solution in an amount providing a bacterial agent concentration level in said solution of between about 5 wppm and about 5,000 wppm.
Claim 21
Dependent Claim
44 words
The reconditioning method defined in claim 16 further comprising the step, after said sulfur removing means has been reconditioned by said steps (a) and (b), of subsequently adding amount of said bactericidal agent sufficient to prevent recontamination of said system by said sulfur-feeding bacteria.
Claim 22
Dependent Claim
42 words
The reconditioning method defined in claim 18 wherein said additional bactericidal agent is added to said solution at a rate so as to maintain a concentration of said bactericidal agent in said solution of between about 10 wppm and about 100 wppm.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-01-29 | 1988-07-30 | 1989-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-29 | 1992-07-30 | 1993-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-29 | 1996-07-30 | 1997-01-29 | $7700.00 | Window Closed / Lapsed |