US3202725A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of xylene
Assignee: Air Products and Chemicals Inc
•
Filing: 1961-06-02
•
Granted: 1965-08-24
•
Expires: 1981-06-02
Abstract
No abstract record available.
Inventors
- 👤 Lorz Waldemar
- 👤 Mills George Alexander
- 👤 Shalit Harold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:53
CPC Classifications
C; C07; C07C; C07C15/00; C07C15/02; C07C15/067; C07C15/08; C07C5/00; C07C5/32; C07C5/327; C07C5/333; C07C5/3332; C07C5/373; C07C5/393; C07C5/41; C07C5/412; Y; Y10; Y10S; Y10S585/00; Y10S585/8995; Y10S585/906
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
183 words
THE METHOD FOR PRODUCTION OF P-XYLENE WHICH COMPRISES: FEEDING TO A CATALYTIC DEHYDROGENATION ZONE MIXED HYDROCARBON STREAMS, INCLUDING AT LEAST ONE RECYCLED PRODUCTS STREAM COMPRISING DIISOBUTYLENE, AND ISOC4 HYDROCARBONS COMPRISING ISOBUTANE, THE RATIO OF ISOC4 HYDROCARBONS TO DIISOBUTYLENE BEING WITHIN THE RANGE FROM ABOUT 2:1 TO ABOUT 3:1; CONTACTING SAID MIXED HYDROCARBON STREAMS IN SAID DEHYDROGENATION ZONE WITH CHROMEALUMINA CATALYST COMPRISING 15 TO 25% CHROMIUM OXIDE, DETERMINED AS CR2/3, AND ALKALI METAL IN AN AMOUNT EQUIVALENT TO AT LEAST 0.6% BY WEIGHT NA2O ON ALUMINA CARRIER, SAID CATALYST HAVING BEEN OBTAINED BY DEHYDRATING BETA ALUMINA TRIHYDRATE TO PRODUCE SORPTIVE ALUMINA HAVING A LARGE SURFACE AREA, LOWERING THE SURFACE AREA TO WITHIN THE RANGE FROM 100 TO 300 AM.2/G. BY TREATMENT WITH HOT STEAM, IMPREGNATING THE SURFACE REDUCED ALUMINA, AND HEATING THE IMPREGNATED ETA ALUMINA, SAID CONTACTING BEING EFFECTED AT A TEMPERATURE IN THE RANGE OF 1000 TO 1100*F. AND PRESSURE IN THE RANGE OF 5-30 INCHES HG ABSOLUTE, AND AT A SPACE RATE CORRELATED THEREWITH TO OBTAIN AT LEAST 50, CONVERSION OF C8 HYDROCARBONS IN THE CHARGE WITH RESULTING PRODUCTION OF PRODUCTS INCLUDING
Claim 2
Independent Claim
183 words
THE METHOD FOR PRODUCTION OF P-XYLENE WHICH COMPRISES: FEEDING TO A CATALYTIC DEHYDROGENATION ZONE MIXED HYDROCARBON STREAMS, INCLUDING AT LEAST ONE RECYCLED PRODUCTS STREAM COMPRISING DIISOBUTYLENE, AND ISOC4 HYDROCARBONS COMPRISING ISOBUTANE, THE RATIO OF ISOC4 HYDROCARBONS TO DIISOBUTYLENE BEING WITHIN THE RANGE FROM ABOUT 2:1 TO ABOUT 3:1; CONTACTING SAID MIXED HYDROCARBON STREAMS IN SAID DEHYDROGENATION ZONE WITH CHROMEALUMINA CATALYST COMPRISING 15 TO 25% CHROMIUM OXIDE, DETERMINED AS CR2/3, AND ALKALI METAL IN AN AMOUNT EQUIVALENT TO AT LEAST 0.6% BY WEIGHT NA2O ON ALUMINA CARRIER, SAID CATALYST HAVING BEEN OBTAINED BY DEHYDRATING BETA ALUMINA TRIHYDRATE TO PRODUCE SORPTIVE ALUMINA HAVING A LARGE SURFACE AREA, LOWERING THE SURFACE AREA TO WITHIN THE RANGE FROM 100 TO 300 AM.2/G. BY TREATMENT WITH HOT STEAM, IMPREGNATING THE SURFACE REDUCED ALUMINA, AND HEATING THE IMPREGNATED ETA ALUMINA, SAID CONTACTING BEING EFFECTED AT A TEMPERATURE IN THE RANGE OF 1000 TO 1100*F. AND PRESSURE IN THE RANGE OF 5-30 INCHES HG ABSOLUTE, AND AT A SPACE RATE CORRELATED THEREWITH TO OBTAIN AT LEAST 50, CONVERSION OF C8 HYDROCARBONS IN THE CHARGE WITH RESULTING PRODUCTION OF PRODUCTS INCLUDING
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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) | 1968-08-23 | 1969-02-22 | 1969-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-08-23 | 1973-02-22 | 1973-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-08-23 | 1977-02-22 | 1977-08-24 | $7700.00 | Window Closed / Lapsed |