US4849558A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of chlorofluorocarbons
Assignee: Honeywell International Inc
•
Filing: 1988-06-30
•
Granted: 1989-07-18
•
Expires: 2008-06-30
Abstract
Abstract Chlorofluorocarbon solvents, particularly R113, may be purified by removing SO 2 or its equivalent to the level of below about 0.3 ppb by contact with alumina or zeolites.
Inventors
- 👤 Walter H. Goodman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 04:43
CPC Classifications
C; C07; C07C; C07C17/00; C07C17/38
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
62 words
A process for purifying chlorofluorocarbon solvents having an initial sulfur content of less than about 10 ppb comprising contacting said solvent with sufficient amount of an adsorbent for sulfur compounds for each unit weight of solvent at about ambient temperature for a period of time sufficient to remove said sulfur compounds in said solvent to a level of 0.3 ppb or below.
Claim 2
Dependent Claim
62 words
A process for purifying chlorofluorocarbon solvents having an initial sulfur content of less than about 10 ppb comprising contacting said solvent with sufficient amount of an adsorbent for sulfur compounds for each unit weight of solvent at about ambient temperature for a period of time sufficient to remove said sulfur compounds in said solvent to a level of 0.3 ppb or below.
Claim 3
Dependent Claim
21 words
The process of claim 1 wherein the sulfur content is derived from sulfur dioxide or a compound which releases sulfur dioxide.
Claim 4
Dependent Claim
10 words
The process of claim 1 wherein the adsorbent is alumina.
Claim 5
Dependent Claim
20 words
The process of claim 3 wherein the amount of alumina is at least about 0.07 grams per gram of solvent.
Claim 6
Dependent Claim
18 words
The process of claim 3 wherein said alumina has been pretreated by air drying at about 600° C.
Claim 7
Dependent Claim
26 words
The process of claim 3 wherein said alumina has been pretreated by washing in aqueous sodium hydroxide solution and thereafter air drying at about 400° C.
Claim 8
Dependent Claim
11 words
The process of claim 1 wherein said adsorbent is a zeolite.
Claim 9
Dependent Claim
13 words
The process of claim 7 wherein said zeolite is a 5A molecular sieve.
Claim 10
Dependent Claim
13 words
The process of claim 7 wherein said zeolite is a 13X molecular sieve.
Claim 11
Dependent Claim
21 words
The process of claim 9 wherein the amount of 13X zeolite is at least about 0.008 gram per gram of solvent.
Claim 12
Dependent Claim
13 words
The process of claim 7 wherein said zeolite is a KX molecular sieve.
Claim 13
Dependent Claim
10 words
The process of claim 1 wherein said solvent is trichlorotrifluoroethane.
Claim 14
Dependent Claim
12 words
The process of claim 1 wherein the temperature is about 20°-45°0 C.
References Cited (Backward Citations)
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JPS48103502A
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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) | 1992-07-17 | 1993-01-16 | 1993-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-17 | 1997-01-16 | 1997-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-17 | 2001-01-16 | 2001-07-18 | $7700.00 | Window Closed / Lapsed |