US4302605A
Expired / Lapsed
US
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Process for the manufacture of dimethyl sulfide
Assignee: Arkema Inc
•
Filing: 1980-04-18
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Granted: 1981-11-24
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Expires: 2000-04-18
Abstract
Abstract A process is provided for preparing dialkyl sulfides by reacting alkanols and hydrogen sulfide in the presence of a zeolite catalyst that contains a reduced amount of alkali metal cations.
Inventors
- 👤 Bernard Buchholz
- 👤 Edward J. Dzierza
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:57
CPC Classifications
C; C07; C07C; C07C319/00; C07C319/14
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
73 words
A continuous vapor-phase process for preparing C 1 -C 12 dialkyl sulfide that comprises reacting a C 1 -C 12 alkanol and hydrogen sulfide at elevated temperature in the presence of a zeolite catalyst having pore openings in the range of from about 7 to about 10 Angstroms, said zeolite catalyst being Type X, Type Y or Type L and containing less than 10% by weight alkali metal, expressed as Na 2 O.
Claim 2
Dependent Claim
73 words
A continuous vapor-phase process for preparing C 1 -C 12 dialkyl sulfide that comprises reacting a C 1 -C 12 alkanol and hydrogen sulfide at elevated temperature in the presence of a zeolite catalyst having pore openings in the range of from about 7 to about 10 Angstroms, said zeolite catalyst being Type X, Type Y or Type L and containing less than 10% by weight alkali metal, expressed as Na 2 O.
Claim 3
Dependent Claim
55 words
The process of claim 1, wherein the crude reaction product consists of a mixture of a C 1 to C 12 mercaptan and the corresponding C 1 to C 12 dialkyl sulfide, and the mercaptan is separated and recycled over the zeolite catalyst to convert it to additional C 1 to C 12 dialkyl sulfide.
Claim 4
Dependent Claim
15 words
The process of claim 2, wherein the catalyst temperature is in the range 250°-450° C.
Claim 5
Dependent Claim
18 words
The process of claim 2, wherein the pressure in the reaction zone ranges from atmospheric to 600 psig.
Claim 6
Dependent Claim
24 words
The process of claim 2, wherein the molar ratio of alkanol to hydrogen sulfide supplied to the reaction system ranges from 3:1 to 1:3.
Claim 7
Dependent Claim
32 words
The process of claim 2, wherein the rate at which the alkanol is passed over the catalyst ranges from 20 to 300 gram-moles of alkanol per kilogram of catalyst per 24 hours.
Claim 8
Dependent Claim
23 words
The process of claim 2, wherein an inert gas is continuously recycled through the reaction zone to remove heat from the exothermic reaction.
Claim 9
Dependent Claim
31 words
The process of claim 2, wherein the alkali metal content of the zeolite catalyst has been reduced below 10% by exchanging the alkali metal ions with protons or catalytically active cations.
Claim 10
Dependent Claim
39 words
The process of claim 2, wherein the alkali metal has been reduced below 10% by exchanging the alkali metal ions with ammonium ions and thereafter the zeolite is calcined to remove at least a major portion of the ammonia.
Claim 11
Dependent Claim
17 words
The process of claim 2, wherein the alkanol is methanol and the dialkyl sulfide is dimethyl sulfide.
Claim 12
Dependent Claim
20 words
The process of claim 10, wherein the alkali metal content, expressed as Na 2 O, is below 3% by weight.
Claim 13
Dependent Claim
29 words
The process of claim 11, wherein the catalyst temperature is in the range 325°-425° C. and the pressure in the reaction zone is in the range of 50-300 psig.
Claim 14
Dependent Claim
52 words
The process of claim 11, wherein the methanol is passed over the zeolite catalyst at a rate in the range of 50-150 gram-moles per kilogram of catalyst per 24 hours, and the molar ratio of methanol to hydrogen sulfide supplied to the reaction system is in the range of 2.5:1 to 1:2.5.
Claim 15
Dependent Claim
25 words
The process of claim 11, wherein the intermediate methyl mercaptan in the crude product is separated and recycled to the reactor containing the zeolite catalyst.
Claim 16
Dependent Claim
51 words
The process of claim 11, wherein an inert gas or mixture of gases selected from the class consisting of nitrogen, carbon dioxide, and a hydrocarbon, is constantly recycled through the reaction zone in sufficient quantity to remove the excess heat from the reaction zone to maintain the desired catalyst bed temperature.
Claim 17
Dependent Claim
61 words
The process of claim 15, wherein methanol and hydrogen sulfide are continuously supplied to the reaction system in a molar ratio of about 2:1, the intermediate methyl mercaptan is continuously separated from the crude reaction product and recycled to the reaction zone, and the remaining crude product is continuously distilled to provide dimethyl sulfide having a purity of at least 99.5%.
References Cited (Backward Citations)
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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) | 1984-11-23 | 1985-05-25 | 1985-11-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-23 | 1989-05-25 | 1989-11-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-23 | 1993-05-25 | 1993-11-24 | $7700.00 | Window Closed / Lapsed |