Patent US3779898A successfully refreshed from Google Patents.
US3779898A
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Catalytic cracking of hydrocarbons with zeolite catalysts
Assignee: Texaco Inc
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Filing: 1970-12-28
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Granted: 1973-12-18
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Expires: 1990-12-28
Abstract
Abstract Significant improvements in catalyst activity and selectivity are achieved in the catalytic cracking of hydrocarbons with catalysts of the zeolite type when the ratio of fresh catalyst addition to catalyst loss is maintained above 1.5 and the catalyst is heat treated at between 1,300* and 1,600* F. for between 5 minutes and 24 hours. The heat treatment is performed on either the fresh catalyst being added or on the combined mixture of fresh catalyst and equilibrium catalyst. Increases in Texaco D + L activity of between 1 and 10 may be achieved with concomitant increases in naphtha selectivity with naphtha yield at constant conversion being increased as much as 5 volume percent.
Inventors
- 👤 D Youngblood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:31
CPC Classifications
C; C10; C10G; C10G11/00; C10G11/14; C10G11/18; Y; Y10; Y10S; Y10S208/00; Y10S208/02
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
17 words
A process according to claim 1 wherein in step (a) the ratio is between 2.0 and 2.5.
Claim 2
Dependent Claim
25 words
A process according to claim 1 where in step (c) the temperature is 1400* to 1550*F. for a period of between 15 and 200 minutes.
Claim 3
Dependent Claim
140 words
In the catalytic cracking of hydrocarbons with a catalyst comprising an active metal oxide and crystalline zeolite, said catalyst having been rendered catalytically active during its preparation by a process comprising calcining and/or steam treatment, wherein periodic additions of catalyst are made to maintain catalyst inventory which is gradually and continually depleted through attrition and loss, the improvement which comprises: a. subjecting fresh catalytic cracking catalyst comprising an active metal oxide and a crystalline zeolite to a temperature of 1300* to 1600*F. for a period of between 5 minutes and 24 hours, b. adding the treated catalyst from step (a) to the inventory of equilibrium catalyst at a ratio of treated catalyst addition to equilibrium catalyst loss greater than about 1.5, and c. withdrawing equilibrium catalyst from the catalyst inventory to maintain the catalyst inventory at a substantially constant value.
Claim 4
Dependent Claim
25 words
A process according to claim 4 where in step (a) the temperature is 1400* to 1550*F. for a period of between 15 and 200 minutes.
Claim 5
Dependent Claim
17 words
A process according to claim 4 where in step (b) the ratio is between 2.0 and 2.5.
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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) | 1976-12-17 | 1977-06-18 | 1977-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-17 | 1981-06-18 | 1981-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-17 | 1985-06-18 | 1985-12-18 | $7700.00 | Window Closed / Lapsed |