Patent US4158737A successfully refreshed from Google Patents.
US4158737A
Expired / Lapsed
US
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Vinyl acetate preparation
Assignee: Millennium Petrochemicals Inc
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Filing: 1978-07-03
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Granted: 1979-06-19
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Expires: 1998-07-03
Abstract
Abstract A Group VIII noble metal catalyst supported on an alumina carrier having an alumina content greater than 99.0%, a crystalline alpha-alumina content of greater than 96%, a theta-alumina content of less than about 3.0%, a total calcium and magnesium content of less than 750 ppm, a surface area of about 2 to 6 m2/g, an average crush strength of from about 20 to 45 lbs., a bulk density of less than about 1.35 g/cc, and an acetic acid loading of less than about 1.5% in 200 hours. The catalyst generally contains an alkali metal carboxylate activator and optionally a metal such as gold, copper, and the like. The catalyst is particularly useful for the preparation of unsaturated organic esters such as vinyl acetate and allyl acetate by a vapor phase process wherein a gaseous mixture of an olefinic compound, a lower carboxylic acid, and oxygen is contacted with the catalyst.
Inventors
- 👤 Raymond C. Bartsch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:36
CPC Classifications
B; B01; B01J; B01J31/00; B01J31/16; B01J31/1616; B01J23/00; B01J23/38; B01J23/40; B01J23/44; B01J23/48; B01J23/52; B01J31/02; B01J31/04; B01J35/00; B01J35/60; C; C07; C07C; C07C67/00; C07C67/04; C07C67/05; C07C67/055; B01J21/00; B01J21/02; B01J21/04; B01J35/61; B01J35/612; B01J35/63; B01J35/633
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
166 words
In a vapor phase process for the preparation of unsaturated organic esters by a process with comprises contacting a gaseous mixture of an olefin having from 1 to 4 carbon atoms, oxygen, and a lower carboxylic acid having from 2 to 4 carbon atoms with a catalyst comprising a Group VIII noble metal and an alkali metal carboxylate having from 2 to 4 carbon atoms on a catalyst carrier at an elevated temperature and pressure, and recovering the resulting organic esters; the improvement which comprises employing as said catalyst carrier alumina having a crystalline alpha-alumina content of greater than about 96%, a theta-alumina content of less than about 3%, a total calcium and magnesium content of less than about 750 ppm, a surface area of from about 2 to 6 m 2 /g, an average crush strength of from about 20 to 45 lbs., a bulk density of less than about 1.35 g/cc, and an acetic acid loading of less than about 1.5% in 200 hours.
Claim 2
Dependent Claim
166 words
In a vapor phase process for the preparation of unsaturated organic esters by a process with comprises contacting a gaseous mixture of an olefin having from 1 to 4 carbon atoms, oxygen, and a lower carboxylic acid having from 2 to 4 carbon atoms with a catalyst comprising a Group VIII noble metal and an alkali metal carboxylate having from 2 to 4 carbon atoms on a catalyst carrier at an elevated temperature and pressure, and recovering the resulting organic esters; the improvement which comprises employing as said catalyst carrier alumina having a crystalline alpha-alumina content of greater than about 96%, a theta-alumina content of less than about 3%, a total calcium and magnesium content of less than about 750 ppm, a surface area of from about 2 to 6 m 2 /g, an average crush strength of from about 20 to 45 lbs., a bulk density of less than about 1.35 g/cc, and an acetic acid loading of less than about 1.5% in 200 hours.
Claim 3
Dependent Claim
19 words
In the process of claim 1 wherein said olefin is ethylene and said lower carboxylic acid is acetic acid.
Claim 4
Dependent Claim
33 words
In the process of claim 1 wherein said Group VIII noble metal is palladium and said alkali metal carboxylate is selected from the group consisting of sodium acetate, potassium acetate and mixtures thereof.
Claim 5
Dependent Claim
13 words
In the process of claim 1 wherein said catalyst also contains gold metal.
Claim 6
Dependent Claim
135 words
In a vapor phase process for the preparation of vinyl acetate which comprises contacting a gaseous mixture of ethylene, oxygen, and acetic acid with a catalyst comprising palladium metal and an alkali metal carboxylate on an alumina carrier at an elevated temperature, and recovering the resulting vinyl acetate; the improvement which comprises employing as said catalyst carrier alumina having a crystalline alpha-alumina content of greater than about 98%, a theta-alumina content of less than about 1.5%, a total calcium and magnesium content of less than about 200 ppm, a surface area of from about 3 to 4.5 m 2 /g, an average crush strength of from about 23 to 33 lbs, a bulk density of less than about 1.30 g/cc, and an acetic acid loading of less than about 1% by weight in 200 hours.
Claim 7
Dependent Claim
135 words
In a vapor phase process for the preparation of vinyl acetate which comprises contacting a gaseous mixture of ethylene, oxygen, and acetic acid with a catalyst comprising palladium metal and an alkali metal carboxylate on an alumina carrier at an elevated temperature, and recovering the resulting vinyl acetate; the improvement which comprises employing as said catalyst carrier alumina having a crystalline alpha-alumina content of greater than about 98%, a theta-alumina content of less than about 1.5%, a total calcium and magnesium content of less than about 200 ppm, a surface area of from about 3 to 4.5 m 2 /g, an average crush strength of from about 23 to 33 lbs, a bulk density of less than about 1.30 g/cc, and an acetic acid loading of less than about 1% by weight in 200 hours.
Claim 8
Dependent Claim
14 words
In the process of claim 5 wherein said alkali metal acetate is sodium acetate.
Claim 9
Dependent Claim
14 words
In the process of claim 5 wherein said alkali metal acetate is potassium acetate.
Claim 10
Dependent Claim
13 words
In the process of claim 5 wherein said catalyst additionally contains gold metal.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-06-18 | 1982-12-18 | 1983-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-06-18 | 1986-12-18 | 1987-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-06-18 | 1990-12-18 | 1991-06-19 | $7700.00 | Window Closed / Lapsed |