US2989544A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of phthalic anhydride from low sulfur naphthalene
Assignee: Wyeth Holdings LLC
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Filing: 1956-02-07
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Granted: 1961-06-20
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Expires: 1976-02-07
Abstract
No abstract record available.
Inventors
- 👤 Kenneth W Saunders
- 👤 James E Longfield
- 👤 Robert C Ryder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:27
CPC Classifications
C; C07; C07C; C07C7/00; C07C7/148; C07C7/14808; C07C7/14816; B; B01; B01J; B01J8/00; B01J8/18; B01J8/1836; C07C51/00; C07C51/16; C07C51/31; C07C51/313; B01J2208/00; B01J2208/00008; B01J2208/00017; B01J2208/00026; B01J2208/00035; B01J2208/0007; B01J2208/00079; B01J2208/00088; B01J2208/00106; B01J2208/00115; B01J2208/00132; B01J2208/0053
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
143 words
A METHOD FOR THE VAPOR PHASE FLUIDIZED CATALYTIC OXIDATION OF NAPHTHALENE TO PHTHALIC ANHYDRIDE WHICH COMPRISES PRETREATING NAPHTHALENE CONTAINING FROM ABOUT 0.1% TO ABOUT 0.7% BY WEIGHT OF SULFUR TO REDUCE THE SULFUR CONTENT TO LESS THAN ABOUT 0.1% BY WEIGHT AND THEN PASSING A MIXTURE OF THE TREATED NAPHTHALENE AND AIR AT A TEMPERATURE OF FROM ABOUT 330* TO ABOUT 425*C. THROUGH A FLUIDIZED CATALYST COMPRISING FROM ABOUT 40% TO ABOUT 75% BY WEIGHT OF A CALCINED GEL OF SILICA IMPREGNATED WITH FROM ABOUT 20% TO ABOUT 50% BY WEIGHT OF A POTASSIUM SULFATE IN WHICH THE MOLAR RATIO OF SO3 TO K2O IS FROM ABOUT 1.9:1 TO 2.1:1 AND FROM ABOUT 3% TO ABOUT 25% OF A VANADIUM OXIDE WHEREBY SAID MOLAR RATIO OF SO3 TO K2O IS MAINTAINED IN THE CATALYST DURING CONTINUED OXIDATION OF THE NAPHTHALENE TO PHTHALIC ANHYDRIDE.
Claim 2
Independent Claim
143 words
A METHOD FOR THE VAPOR PHASE FLUIDIZED CATALYTIC OXIDATION OF NAPHTHALENE TO PHTHALIC ANHYDRIDE WHICH COMPRISES PRETREATING NAPHTHALENE CONTAINING FROM ABOUT 0.1% TO ABOUT 0.7% BY WEIGHT OF SULFUR TO REDUCE THE SULFUR CONTENT TO LESS THAN ABOUT 0.1% BY WEIGHT AND THEN PASSING A MIXTURE OF THE TREATED NAPHTHALENE AND AIR AT A TEMPERATURE OF FROM ABOUT 330* TO ABOUT 425*C. THROUGH A FLUIDIZED CATALYST COMPRISING FROM ABOUT 40% TO ABOUT 75% BY WEIGHT OF A CALCINED GEL OF SILICA IMPREGNATED WITH FROM ABOUT 20% TO ABOUT 50% BY WEIGHT OF A POTASSIUM SULFATE IN WHICH THE MOLAR RATIO OF SO3 TO K2O IS FROM ABOUT 1.9:1 TO 2.1:1 AND FROM ABOUT 3% TO ABOUT 25% OF A VANADIUM OXIDE WHEREBY SAID MOLAR RATIO OF SO3 TO K2O IS MAINTAINED IN THE CATALYST DURING CONTINUED OXIDATION OF THE NAPHTHALENE TO PHTHALIC ANHYDRIDE.
Claim 3
Dependent Claim
124 words
IN A PROCESS FOR THE VAPOR PHASE CATALYTIC CONVERSION OF SULFUR-CONTAINING AROMATIC HYDROCARBONS TO INTERMEDIATE OXIDATION PRODUCTS WHEREIN AROMATIC HYDROCARBON VAPORS IN ADMIXTURE WITH AN OXIDIZING GAS ARE PASSED AT REACTION TEMPERATURES OF ABOUT 320*-425*C. AND CONTACT TIMES OF 3-25 SECONDS THROUGH A BED OF FINELY DIVIDED FLUIDIZED CATALYST CONTAINING A SILICA GEL CARRIER SUPPORTING A MIXTURE OF VANADIUM OXIDES AND A POTASSIUM SULFATE IN WHICH THE MOLAR RATIO OF SO3 TO K2O IS FROM ABOUT 1.9:1 TO 2.1:1 THE IMPROVEMENT WHICH COMPRISES MAINTAINING SAID MOLAR RATIO OF SO3 TO K2O IN THE CATALYST BY DESULFURIZING SAID SULFUR-CONTAINING HYDROCARBONS TO A SULFUR CONTENT LESS THAN 0.1% PRIOR TO THEIR CONTACT THEREWITH AND THEREBY AVOIDING LOSS OF CATALYST ACTIVITY DURING LONG-CONTINUED OPERATION OF THE PROCESS.
Claim 4
Dependent Claim
124 words
IN A PROCESS FOR THE VAPOR PHASE CATALYTIC CONVERSION OF SULFUR-CONTAINING AROMATIC HYDROCARBONS TO INTERMEDIATE OXIDATION PRODUCTS WHEREIN AROMATIC HYDROCARBON VAPORS IN ADMIXTURE WITH AN OXIDIZING GAS ARE PASSED AT REACTION TEMPERATURES OF ABOUT 320*-425*C. AND CONTACT TIMES OF 3-25 SECONDS THROUGH A BED OF FINELY DIVIDED FLUIDIZED CATALYST CONTAINING A SILICA GEL CARRIER SUPPORTING A MIXTURE OF VANADIUM OXIDES AND A POTASSIUM SULFATE IN WHICH THE MOLAR RATIO OF SO3 TO K2O IS FROM ABOUT 1.9:1 TO 2.1:1 THE IMPROVEMENT WHICH COMPRISES MAINTAINING SAID MOLAR RATIO OF SO3 TO K2O IN THE CATALYST BY DESULFURIZING SAID SULFUR-CONTAINING HYDROCARBONS TO A SULFUR CONTENT LESS THAN 0.1% PRIOR TO THEIR CONTACT THEREWITH AND THEREBY AVOIDING LOSS OF CATALYST ACTIVITY DURING LONG-CONTINUED OPERATION OF THE PROCESS.
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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) | 1964-06-19 | 1964-12-19 | 1965-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-06-19 | 1968-12-19 | 1969-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-06-19 | 1972-12-19 | 1973-06-20 | $7700.00 | Window Closed / Lapsed |