Patent US4472587A successfully refreshed from Google Patents.
US4472587A
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Process for obtaining phthalic anhydride, starting from ortho-xylene, naphtalene and their mixtures, by oxidation in the presence of a specific catalyst and the catalyst obtained by carrying out said process
Assignee: CARBOCHIMICA ITALIANA SP A
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Filing: 1982-05-18
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Granted: 1984-09-18
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Expires: 2002-05-18
Abstract
Abstract The present invention concerns a process for obtaining phthalic anhydride by oxidizing ortho-xylene, naphthalene, or mixtures of the two, in the presence of a specific catalyst with a vanadium pentoxide and titanium dioxide base, and also regards the catalyst obtained by enactment of said process.
Inventors
- 👤 Francesco Benedetti
- 👤 Ezio Polacco
- 👤 Angelo Celli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:06
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/16; C07C51/21; C07C51/255; C07C51/265; B; B01; B01J; B01J23/00; B01J23/16; B01J23/20; B01J23/22; C07C51/31; C07C51/313
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
92 words
In an industrial process for production of phthalic anhydride in the presence of a vanadium pentoxide and titanium dioxide base catalyst, the improvement comprising employing an ortho-xylene and naphthalene mixed feed, the relative proportions of ortho-xylene and naphthalene being varied from 100% to 0% and 0% to %100, respectively, over time proportionally and in dependence upon the physical and chemical condition of the vanadium pentoxide and titanium dioxide base catalyst, said proportions of ortho-xylene and naphthalene in said feed being integrated so as to result in a monitored phthalide production below 0.1%.
Claim 2
Dependent Claim
92 words
In an industrial process for production of phthalic anhydride in the presence of a vanadium pentoxide and titanium dioxide base catalyst, the improvement comprising employing an ortho-xylene and naphthalene mixed feed, the relative proportions of ortho-xylene and naphthalene being varied from 100% to 0% and 0% to %100, respectively, over time proportionally and in dependence upon the physical and chemical condition of the vanadium pentoxide and titanium dioxide base catalyst, said proportions of ortho-xylene and naphthalene in said feed being integrated so as to result in a monitored phthalide production below 0.1%.
Claim 3
Dependent Claim
34 words
A process as defined in claim 1, wherein said feed is adjusted in amount and relative proportions of ortho-xylene and naphthalene substantially in accordance with the integrative feed chart as illustrated in FIG. 2.
Claim 4
Dependent Claim
22 words
A process as defined in claim 1, wherein naphthalene is first introduced into said feed after about the 50th month of operation.
Claim 5
Dependent Claim
21 words
A process as defined in claim 1, wherein naphthalene is evaporated and mixed with air before introduction into an oxidation reactor.
Claim 6
Dependent Claim
54 words
A process as defined in claim 1, wherein naphthalene is evaporated in a carburetor into which said naphthalene is fed at a temperature between 70° and 85° C., said carburetor having a discharge at the bottom thereof wherefrom naphthalene is removed and sent to a series of heat-exchangers before being recycled to said carburetor.
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) | 1987-09-18 | 1988-03-19 | 1988-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-18 | 1992-03-19 | 1992-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-18 | 1996-03-19 | 1996-09-18 | $7700.00 | Window Closed / Lapsed |