US3178486A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Catalytic hydrodealkylation of alkyl substituted benzenoid hydrocarbons
Assignee: Air Products and Chemicals Inc
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Filing: 1962-09-05
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Granted: 1965-04-13
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Expires: 1982-09-05
Abstract
No abstract record available.
Inventors
- 👤 John B Maerker
- 👤 Alvin H Weiss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:54
CPC Classifications
C; C07; C07C; C07C4/00; C07C4/08; C07C4/12; C07C4/14; C07C4/18; C07C2521/00; C07C2521/02; C07C2521/04; C07C2523/00; C07C2523/16; C07C2523/24; C07C2523/26; Y; Y10; Y10S; Y10S585/00; Y10S585/8995; Y10S585/903; Y10S585/909; Y10S585/91
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
149 words
THE METHOD OF HYDRODEALKYLATION OF ALKYL AROMATIC HYDROCARBONS WHICH COMPRISES: CONTACTING SUCH HYDROCARBONS IN A PLURALITY OF REACTION ZONES WITH HIGH ACTIVITY CHROME-ALUMINA CATALYST AT A TEMPERATURE IN EXCESS OF 1100*F., THE EFFLUENT FROM EACH SAID REACTION ZONE BEING ADJUSTED IN TEMPERATURE BEFORE ENTERING THE NEXT SUCCEEDING REACTION ZONE SO THAT THE REACTION TEMPERATURE IN EACH ZONE AS A RESULT OF THE REACTION EXOTHERM THEREIN IS MAINTAINED BELOW A MAXIMUM OF 1225*F., THE NUMBER OF SUCH ZONES BEING SUFFICIENT TO EFFECT THE COVERSION OF AT LEAST 50% BY WEIGHT OF SAID ALKYL AROMATIC HYDROCARBONS CHARGED AND TO PROVIDE A TOTAL CONTACT TIME OF 30 TO 180 SECONDS, THE REACTION CONDITIONS IN EACH ZONE INCLUDING A HYDROGEN TO AROMATICS RATIO OF AT LEAST 3 TO 1; SAID CATALYST CONTAINING 15 TO 25% CR2O3 INCORPORATED IN AN ALUMINA BASE DERIVED FROM DEHYDRATION OF HYDROUS ALUMIN CONTAINING AT LEAST 50% BETA TRIHYDRATE.
Claim 2
Independent Claim
149 words
THE METHOD OF HYDRODEALKYLATION OF ALKYL AROMATIC HYDROCARBONS WHICH COMPRISES: CONTACTING SUCH HYDROCARBONS IN A PLURALITY OF REACTION ZONES WITH HIGH ACTIVITY CHROME-ALUMINA CATALYST AT A TEMPERATURE IN EXCESS OF 1100*F., THE EFFLUENT FROM EACH SAID REACTION ZONE BEING ADJUSTED IN TEMPERATURE BEFORE ENTERING THE NEXT SUCCEEDING REACTION ZONE SO THAT THE REACTION TEMPERATURE IN EACH ZONE AS A RESULT OF THE REACTION EXOTHERM THEREIN IS MAINTAINED BELOW A MAXIMUM OF 1225*F., THE NUMBER OF SUCH ZONES BEING SUFFICIENT TO EFFECT THE COVERSION OF AT LEAST 50% BY WEIGHT OF SAID ALKYL AROMATIC HYDROCARBONS CHARGED AND TO PROVIDE A TOTAL CONTACT TIME OF 30 TO 180 SECONDS, THE REACTION CONDITIONS IN EACH ZONE INCLUDING A HYDROGEN TO AROMATICS RATIO OF AT LEAST 3 TO 1; SAID CATALYST CONTAINING 15 TO 25% CR2O3 INCORPORATED IN AN ALUMINA BASE DERIVED FROM DEHYDRATION OF HYDROUS ALUMIN CONTAINING AT LEAST 50% BETA TRIHYDRATE.
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) | 1968-04-12 | 1968-10-12 | 1969-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-04-12 | 1972-10-12 | 1973-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-04-12 | 1976-10-12 | 1977-04-13 | $7700.00 | Window Closed / Lapsed |