US5208069A
Expired / Lapsed
US
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Method for passivating the inner surface by deposition of a ceramic coating of an apparatus subject to coking, apparatus prepared thereby, and method of utilizing apparatus prepared thereby
Assignee: Istituto Guido Donegani SpA
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Filing: 1991-10-28
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Granted: 1993-05-04
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Expires: 2011-10-28
Abstract
Abstract In order to reduce the rate of coke formation during the industrial pyrolysis of hydrocarbons, the interior surface of the reactor tubes are coated with a thin layer of a ceramic material, said layer being deposited by thermal decomposition of a non-oxygen containing silicon organometallic precursor in the vapor phase, in an inert or reducing gas atmosphere in order to minimize the formation of oxide ceramics.
Inventors
- 👤 Terence J. Clark
- 👤 Michael J. Hanagan
- 👤 Richard W. Cruse
- 👤 Veronika A. Szalai
- 👤 Stephen J. Rohman
- 👤 Robert M. Mininni
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:42
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/22; C23C16/30; C23C16/32; C23C16/325; B; B01; B01J; B01J19/00; B01J19/0006; B01J19/002; B01J19/0026; C01; C01B; C01B3/00; C01B3/02; C01B3/22; C01B3/24; C04; C04B; C04B41/00; C04B41/45; C04B41/4505; C04B41/455; C04B41/4554; C10; C10G; C10G9/00; C10G9/14; C10G9/16; C23C16/34; C23C16/345; C23C16/36
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
108 words
A method for passivating the inner surface of a metallic reactor tube which is used in steam or steamless hydrocarbon pyrolysis, comprising decomposing at 700° C.-900° C. a non-oxygen containing silicon containing precursor selected from the group consisting of hexamethyldisilazane, tetramethylsilane, (diethylamino)trimethylsilane, (isopropylamino)trimethylsilane, (dimethylamino)trimethylsilane, heptamethyldisilazane, bis(isopropylamino)dimethylsilane, hexamethyldisilane, tetramethyldisilazane, (diethylamino)triethylsilane, tetrakis(dimethylamino)silane, bis(dimethylamino)methylsilane, (dimethylamino)triethylsilane, trimethylsilane, (dimethylamino)benzyldimethylsilane, (dimethylamino)phenylmethylsilane, (2-picolylamino)trimethylsilane, tris(isopropylamino)methylsilane, dimethylsilane, bis(diethylamino)methylsilane, (dimethylamino)benzylmethylsilane, butylmethylphenylsilane, (diisopropylamino)methylchlorosilane, octamethyltrisilazane, bis(dimethylamino)phenylsilane, benzylmethylchlorosilane, triisopropylsilane, tris(dimethylamino)methylsilane, diethylmethylsilane, triethylsilane, bis(dimethylamino)ethylsilane, hexamethyltrisilazane, and (dimethylamino)dimethylsilane, in the vapor phase, in an inert or reducing gas atmosphere in said tube to form a thin layer of 1 to 20 μm of a ceramic material on a surface of said reactor tube.
Claim 2
Independent Claim
108 words
A method for passivating the inner surface of a metallic reactor tube which is used in steam or steamless hydrocarbon pyrolysis, comprising decomposing at 700° C.-900° C. a non-oxygen containing silicon containing precursor selected from the group consisting of hexamethyldisilazane, tetramethylsilane, (diethylamino)trimethylsilane, (isopropylamino)trimethylsilane, (dimethylamino)trimethylsilane, heptamethyldisilazane, bis(isopropylamino)dimethylsilane, hexamethyldisilane, tetramethyldisilazane, (diethylamino)triethylsilane, tetrakis(dimethylamino)silane, bis(dimethylamino)methylsilane, (dimethylamino)triethylsilane, trimethylsilane, (dimethylamino)benzyldimethylsilane, (dimethylamino)phenylmethylsilane, (2-picolylamino)trimethylsilane, tris(isopropylamino)methylsilane, dimethylsilane, bis(diethylamino)methylsilane, (dimethylamino)benzylmethylsilane, butylmethylphenylsilane, (diisopropylamino)methylchlorosilane, octamethyltrisilazane, bis(dimethylamino)phenylsilane, benzylmethylchlorosilane, triisopropylsilane, tris(dimethylamino)methylsilane, diethylmethylsilane, triethylsilane, bis(dimethylamino)ethylsilane, hexamethyltrisilazane, and (dimethylamino)dimethylsilane, in the vapor phase, in an inert or reducing gas atmosphere in said tube to form a thin layer of 1 to 20 μm of a ceramic material on a surface of said reactor tube.
Claim 3
Dependent Claim
43 words
The method according to claim 1, wherein said ceramic material consists essentially of silicon carbide, silicon nitride, silicon carbonitride or mixtures thereof, and said ceramic material contains 0 to 20 mol. % of oxygen and 0 to 30 mol. % of free carbon.
Claim 4
Dependent Claim
27 words
The method according to claim 1, wherein said silicon containing precursor is a silicon compound which is volatile at temperatures below those employed in the deposition process.
Claim 5
Dependent Claim
13 words
The method according to claim 1, wherein said silicon containing precursor is hexamethyldisilazane.
Claim 6
Dependent Claim
13 words
The method according to claim 1, wherein said silicon containing precursor is (dimethylamino)triethylsilane.
Claim 7
Dependent Claim
13 words
The method according to claim 1, wherein said silicon containing precursor is octamethyltrisilazane.
Claim 8
Dependent Claim
13 words
The method according to claim 1, wherein said silicon containing precursor is bis(dimethylamino)methylsilane.
Claim 9
Dependent Claim
29 words
The method according to claim 1, wherein said inert or reducing gas is selected from the group consisting of nitrogen, argon, helium, methane, ethylene, ethane, hydrogen and mixtures thereof.
Claim 10
Dependent Claim
14 words
The method according to claim 8, wherein said inert or reducing gas is nitrogen.
Claim 11
Dependent Claim
15 words
The method according to claim 8, wherein said inert or reducing gas is methane/hydrogen mixtures.
Claim 12
Dependent Claim
26 words
The method according to claim 8, wherein said inert or reducing gas is selected from the group consisting of methane, ethylene, hydrogen, ethan and mixtures thereof.
Claim 13
Dependent Claim
26 words
The method according to claim 1, wherein the concentration of said silicon containing precursor in said inert or reducing gas is less than 10.0 volume percent.
Claim 14
Dependent Claim
26 words
The method according to claim 12, wherein the concentration of said silicon containing precursor in said inert or reducing gas is less than 5.0 volume percent.
References Cited (Backward Citations)
US1234886A
Cited
US2580002A
Cited
US3536776A
Cited
US3796592A
Cited
US3746569A
Cited
GB1332569A
Cited
US3781173A
Cited
US4099990A
Cited
US4371944A
Cited
US4906442A
Cited
US4780196A
Cited
US4999228A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-05-03 | 1996-11-02 | 1997-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-03 | 2000-11-02 | 2001-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-03 | 2004-11-02 | 2005-05-04 | $7700.00 | Window Closed / Lapsed |