US5262198A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing a carbon coated ceramic membrane and associated product
Assignee: Alcoa Corp
•
Filing: 1991-04-08
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Granted: 1993-11-16
•
Expires: 2011-04-08
Abstract
Abstract A method of producing a carbon coated ceramic membrane including passing a selected hydrocarbon vapor through a ceramic membrane and controlling ceramic membrane exposure temperature and ceramic membrane exposure time. The method produces a carbon coated ceramic membrane of reduced pore size and modified surface properties having increased chemical, thermal and hydrothermal stability over an uncoated ceramic membrane.
Inventors
- 👤 Paul K. T. Liu
- 👤 George R. Gallaher
- 👤 Jeffrey C. S. Wu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:06
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0039; B01D67/0067; B01D67/0072; B01D69/00; B01D69/04; B01D71/00; B01D71/02; B01D71/021; B01J; B01J35/00; B01J35/50; B01J35/58; B01J35/59; C; C23; C23C; C23C16/00; C23C16/04; C23C16/045; C23C16/22; C23C16/26; B01D2323/00; B01D2323/08; B01D2323/081
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
80 words
A method of producing a carbon coated ceramic membrane comprising: passing a selected hydrocarbon vapor through a ceramic membrane and controlling ceramic membrane exposure temperature and ceramic membrane exposure time, said ceramic membrane exposure temperature being at least 350° C. and said ceramic membrane exposure time depending on said ceramic membrane exposure temperature, to form a carbon coated ceramic membrane of reduced pore size and modified surface properties having increased chemical, thermal and hydrothermal stability over an uncoated ceramic membrane.
Claim 2
Independent Claim
80 words
A method of producing a carbon coated ceramic membrane comprising: passing a selected hydrocarbon vapor through a ceramic membrane and controlling ceramic membrane exposure temperature and ceramic membrane exposure time, said ceramic membrane exposure temperature being at least 350° C. and said ceramic membrane exposure time depending on said ceramic membrane exposure temperature, to form a carbon coated ceramic membrane of reduced pore size and modified surface properties having increased chemical, thermal and hydrothermal stability over an uncoated ceramic membrane.
Claim 3
Dependent Claim
11 words
The method of claim 1, wherein said selected hydrocarbon is ethylbenzene.
Claim 4
Dependent Claim
16 words
The method of claim 2, wherein said ceramic membrane exposure time is 1 to 5 hours.
Claim 5
Dependent Claim
17 words
The method of claim 3, wherein said ceramic membrane exposure temperature is 575° C. to 675° C.
Claim 6
Dependent Claim
28 words
The method of claim 4, wherein said ceramic membrane exposure time is 31/2 to 41/2 hours and said ceramic membrane exposure temperature is 630° C. to 650° C.
Claim 7
Dependent Claim
11 words
The method of claim 1, wherein said selected hydrocarbon is propylene.
Claim 8
Dependent Claim
16 words
The method of claim 6, wherein said ceramic membrane exposure time is 1 to 5 hours.
Claim 9
Dependent Claim
17 words
The method of claim 7, wherein said ceramic membrane exposure temperature is 350° C. to 650° C.
Claim 10
Dependent Claim
28 words
The method of claim 8, wherein said ceramic membrane exposure time is 2 to 4 hours and said ceramic membrane exposure temperature is 400° C. to 600° C.
Claim 11
Dependent Claim
34 words
The method of claim 1, including pretreating to clean said ceramic membrane by passing an inert gas through said ceramic membrane, which has been heated to at least 400° C., to purge desorbing gases.
Claim 12
Dependent Claim
18 words
The method of claim 10, wherein said elevated temperature is 400° C. to said ceramic membrane exposure temperature.
Claim 13
Dependent Claim
21 words
The method of claim 1, including pretreating to modify surface chemistry and composition of said ceramic membrane to promote carbon deposition.
Claim 14
Dependent Claim
15 words
The method of claim 12, wherein said pretreating step modifies acidity of said ceramic membrane.
Claim 15
Dependent Claim
14 words
The method of claim 13, wherein said pretreating step promotes deposition of catalytic material.
Claim 16
Dependent Claim
33 words
The method of claim 1, including after passing a hydrocarbon containing vapor through said ceramic membrane, subsequently heating said ceramic membrane to a carbon coating exposure temperature of 700° C. to 1000° C.
Claim 17
Dependent Claim
17 words
The method of claim 15, wherein said carbon coating exposure temperature is 750° C. to 850° C.
Claim 18
Dependent Claim
24 words
The method of claim 1, including providing said ceramic membrane having a tube shape with a first open end and a second open end.
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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) | 1996-11-15 | 1997-05-17 | 1997-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-11-15 | 2001-05-17 | 2001-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-11-15 | 2005-05-17 | 2005-11-16 | $7700.00 | Window Closed / Lapsed |