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US3855280A Expired / Lapsed US ⏱️ 0.0 years remaining

Process for producing an alkenyl alkanoate from an olefin and a carboxylic acid

Assignee: Celanese Corp
•
Filing: 1972-12-08
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Granted: 1974-12-17
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Expires: 1992-12-08
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Abstract

Abstract In a process for producing an alkenyl carboxylate, such as vinyl acetate, by reacting a carboxylic acid catalytically with an olefin in the presence of molecular oxygen under conditions which are maintained on the fuel-rich or oxygen-poor side of the explosive range, the lower limit of allowable oxygen concentration in the mixed reactants is increased, facilitating operation at increased oxygen concentration with resulting increase in reaction conversion rate, by incorporating a lower alkane, especially methane or ethane, into the mixture of gases being introduced into the reaction zone.

Inventors

  • 👤 G Severs

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 06:05
CPC Classifications
C; C07; C07C; C07C67/00; C07C67/04; C07C67/05; C07C67/055

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 194 words
IN A PROCESS FOR PREPARING VINYL ACETATE BY PASSING A GASEOUS REACTANT MIXTURE COMPRISING MOLECULAR OXYGEN, ETHYLENE, AND ACETIC ACID THROUGH A REACTION ZONE MAINTAINED AT A PRESSURE BETWEEN ABOUT 5 AND ABOUT 15 ATMOSPHERES ABSOLUTE AND CONTAINING A CATALYST COMPRISING A GROUP VIII NOBLE METAL AND REACTING SAID ETHYLENE, OXYGEN AND ACETIC ACID IN THE PRESENCE OF SAID SOLID CATALYST TO FORM VINYL ACETATE, THE COMPOSITION OF SAID GASEOUS REACTION MIXTURE BEING CONTOLLED ON THE FUEL-RICH SIDE OF THE RANGE OF POTENTIALLY EXPLOSIVE MIXTURES OF OXYGEN WITH THE REMAINING COMPONENTS OF SAID REACTION MIXTURE THE DEGREE OF CONVERSION OF THE REACTANTS WITHIN SAID REACTION ZONE BEING LIMITED BY THE NECESSITY OF MAINTAINING THE CONCENTRATION OF OXYGEN THEREIN BELOW THE LOWER EXPLOSIVE LIMIT, THE IMPROVEMENT WHICH COMPRISES: RAISING THE LOWER EXPLOSIVE LIMIT OF OXYGEN IN SAID REACTANT GAS MIXTURE, AND SO FACILITATING SAFE OPERATION AT AN INCREASED OXYGEN CONCENTRATION, BY INCORPORATING FROM ABOUT 0.1 TO ABOUT 0.8 MOLES PER MOLE OF ETHYLENE OF A DILUENT GAS CONSISTING ESSENTIALLY OF A LOWER ALKANE WHICH IS FREE OF SECONDARY AND TERTIARY HYDROGEN ATOMS INTO SAID REACTANT GAS MIXTURE PRIOR TO PASSING IT THROUGH SAID REACTION ZONE.
Claim 2
Dependent Claim 194 words
IN A PROCESS FOR PREPARING VINYL ACETATE BY PASSING A GASEOUS REACTANT MIXTURE COMPRISING MOLECULAR OXYGEN, ETHYLENE, AND ACETIC ACID THROUGH A REACTION ZONE MAINTAINED AT A PRESSURE BETWEEN ABOUT 5 AND ABOUT 15 ATMOSPHERES ABSOLUTE AND CONTAINING A CATALYST COMPRISING A GROUP VIII NOBLE METAL AND REACTING SAID ETHYLENE, OXYGEN AND ACETIC ACID IN THE PRESENCE OF SAID SOLID CATALYST TO FORM VINYL ACETATE, THE COMPOSITION OF SAID GASEOUS REACTION MIXTURE BEING CONTOLLED ON THE FUEL-RICH SIDE OF THE RANGE OF POTENTIALLY EXPLOSIVE MIXTURES OF OXYGEN WITH THE REMAINING COMPONENTS OF SAID REACTION MIXTURE THE DEGREE OF CONVERSION OF THE REACTANTS WITHIN SAID REACTION ZONE BEING LIMITED BY THE NECESSITY OF MAINTAINING THE CONCENTRATION OF OXYGEN THEREIN BELOW THE LOWER EXPLOSIVE LIMIT, THE IMPROVEMENT WHICH COMPRISES: RAISING THE LOWER EXPLOSIVE LIMIT OF OXYGEN IN SAID REACTANT GAS MIXTURE, AND SO FACILITATING SAFE OPERATION AT AN INCREASED OXYGEN CONCENTRATION, BY INCORPORATING FROM ABOUT 0.1 TO ABOUT 0.8 MOLES PER MOLE OF ETHYLENE OF A DILUENT GAS CONSISTING ESSENTIALLY OF A LOWER ALKANE WHICH IS FREE OF SECONDARY AND TERTIARY HYDROGEN ATOMS INTO SAID REACTANT GAS MIXTURE PRIOR TO PASSING IT THROUGH SAID REACTION ZONE.
Claim 3
Dependent Claim 69 words
The improvement of claim 1 wherein the catalyst is a solid and wherein the diluent gas consists essentially of at least one member of the group consisting of methane and ethane which is incorporated into the reactant gas mixture in such an amount that the resulting diluted mixture as introduced into the reaction zone contains from aboUt 0.1 to about 0.8 mole of alkane diluent per mole of ethylene.
Claim 4
Dependent Claim 56 words
The improvement of claim 2 wherein the gaseous reactant mixture, prior to incorporation of the diluent thereinto, comprises, on the oxygen-free basis, about 50 to 70 volume percent ethylene, 7 to 14 volume percent acetic acid, and the remainder inert gases comprising predominantly carbon dioxide with minor amounts of methane, ethane, nitrogen, argon, and water vapor.
Claim 5
Dependent Claim 40 words
The improvement of claim 3 wherein the noble metal catalyst comprises palladium and the reaction in the reaction zone is conducted at a pressure between about 5 and 15 atmospheres absolute and at a temperature between about 130*C and 210*C.
Claim 6
Dependent Claim 11 words
The improvement of claim 4 wherein the diluent gas is methane.
Claim 7
Dependent Claim 80 words
The improvement of claim 5 wherein, after introduction of the diluent, the reactant gases introduced into the reactor comprise by volume, approximately 40 to 60% ethylene, 5 to 30% methane, 7 to 14% acetic acid, 6 to 10% molecular oxygen, and the remainder minor inert gases comprising carbon dioxide, arbon, nitrogen, and water vapor, and wherein the reaction zone is controlled at a temperature between about 150* and 190*C and at a pressure between about 7 and 12 atmospheres absolute.
Claim 8
Dependent Claim 32 words
The improvement of claim 3 wherein the diluent gas is incorporated into the reactant gas mixture by replacing a portion of the ethylene with the diluent gas on an approximately mole-for-mole basis.
Claim 9
Dependent Claim 92 words
The improvement of claim 3 further characterized by the method of maintaining optimal sustained reaction zone productivity after said alkane dilution by adjusting the reaction zone temperature within the range of about 150*C to 190*C as necessary to maintain the portion of ethylene converted to carbon dioxide within the range of about 5% to 15% of the total amount of ethylene converted to all reaction products per reaction pass, said adjustment comprising raising the reaction zone temperature to increase said conversion to carbon dioxide and reducing said temperature to reduce said conversion.

References Cited (Backward Citations)

US3300528A Cited
US3404177A Cited
US3600429A Cited
US3634496A Cited
US3641121A Cited
BE770681A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1977-12-16 1978-06-17 1978-12-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1981-12-16 1982-06-17 1982-12-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1985-12-16 1986-06-17 1986-12-17 $7700.00 Window Closed / Lapsed

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