US4545940A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of dewaxing a vegetable oil
Assignee: Asahi Kasei Corp
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Filing: 1983-03-31
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Granted: 1985-10-08
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Expires: 2003-03-31
Abstract
Abstract A method of dewaxing a vegetable oil which comprises adjusting the temperature of a vegetable oil containing a wax to allow the wax to crystallize and subjecting the temperature-adjusted oil to filtration by means of a porous membrane having a critical surface tension (γc) of less than 33 dynes/cm and having an average pore diameter of 0.05 to 5 μm, thereby selectively permeating the vegetable oil through the membrane while separating the wax from the vegetable oil. The process of the present invention is useful not only for dewaxing a vegetable oil but also for removing a wax together with a phospholipid, a free fatty acid and water from a crude vegetable oil.
Inventors
- 👤 Yoshihiko Mutoh
- 👤 Kazuo Matsuda
- 👤 Masashi Ohshima
- 👤 Hiroo Ohuchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:12
CPC Classifications
C; C11; C11B; C11B3/00; C11B3/008; B; B01; B01D; B01D61/00; B01D61/14; B01D63/00; B01D63/02; B01D63/08; B01D63/087; B01D63/14
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
114 words
A method of dewaxing a vegetable oil which comprises: adjusting the temperature of a vegetable oil containing a wax to a temperature of about -10° C. to about 20° C. to allow the wax to crystallize; and subjecting the temperature-adjusted vegetable oil to filtration by means of a porous membrane having pores which form passages running through the membrane from one surface thereof to the other surface thereof, said porous membrane having at its surface a critical surface tension (γc) of less than 33 dynes/cm and having an average pore diameter of 0.05 to 5 μm, thereby selectively permeating the vegetable oil through the membrane while separating the crystallized wax from the vegetable oil.
Claim 2
Independent Claim
114 words
A method of dewaxing a vegetable oil which comprises: adjusting the temperature of a vegetable oil containing a wax to a temperature of about -10° C. to about 20° C. to allow the wax to crystallize; and subjecting the temperature-adjusted vegetable oil to filtration by means of a porous membrane having pores which form passages running through the membrane from one surface thereof to the other surface thereof, said porous membrane having at its surface a critical surface tension (γc) of less than 33 dynes/cm and having an average pore diameter of 0.05 to 5 μm, thereby selectively permeating the vegetable oil through the membrane while separating the crystallized wax from the vegetable oil.
Claim 3
Dependent Claim
15 words
A method according to claim 1, wherein said porous membrane is a hollow fiber membrane.
Claim 4
Dependent Claim
92 words
A method according to claim 1, wherein said porous membrane is a hollow fiber membrane and which further comprises, in the filtration of the temperature-adjusted vegetable oil, intermittently stopping the filtration and subjecting the hollow fiber membrane to backwash treatment and/or flushing treatment by means of a fluid of 30° C. to 100° C., said fluid being a liquid selected from the group consisting of the vegetable oil permeated through the membrane, n-hexane and acetone, or a gas selected from the group consisting of air, nitrogen, oxygen, carbonic acid, argon and helium.
Claim 5
Dependent Claim
17 words
A method according to claim 1, wherein said porous membrane has a porosity of 15 to 95%.
Claim 6
Dependent Claim
18 words
A method according to claim 2, wherein said hollow fiber membrane has a porosity of 15 to 95%.
Claim 7
Dependent Claim
18 words
A method according to claim 3, wherein said hollow fiber membrane has a porosity of 15 to 95%.
Claim 8
Dependent Claim
18 words
A method according to claim 1, wherein said porous membrane has a thickness of 0.01 to 4 mm.
Claim 9
Dependent Claim
19 words
A method according to claim 2, wherein said hollow fiber membrane has a thickness of 0.01 to 4 mm.
Claim 10
Dependent Claim
19 words
A method according to claim 3, wherein said hollow fiber membrane has a thickness of 0.01 to 4 mm.
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) | 1988-10-07 | 1989-04-08 | 1989-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-07 | 1993-04-08 | 1993-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-07 | 1997-04-08 | 1997-10-08 | $7700.00 | Window Closed / Lapsed |