Patent EP0540084A1 successfully refreshed from Google Patents.
EP0540084A1
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Method for passivating the inner surface of a reactor subject to coking, by deposition of a ceramic coating, and method of pyrolyzing hydrocarbons
Assignee: Enichem SpA
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Filing: 1992-10-17
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Granted: —
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Expires: 2012-10-17
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. Little Valley Farm Apt.14 Hanagan
- 👤 Richard W. Cruse
- 👤 Veronika A. Szalai
- 👤 Stephen J. Rohman
- 👤 Robert M. Mininni
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 01:20
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: 20
Claim 1
Independent Claim
54 words
A method for passivating the inner surface of a reactor tube which is subject to coking, comprising decomposing a non-oxygen containing silicon organometallic precursor in the vapor phase, in an inert or reducing gas atmosphere in said tube to form a thin layer of a ceramic material on a surface of said reactor tube.
Claim 2
Dependent Claim
19 words
The method of Claim 1, wherein said reactor is a reactor tube used in steam or steamless hydrocarbon pyrolysis.
Claim 3
Dependent Claim
43 words
The method according to Claim 2, 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 2, wherein said silicon organometallic precursor is a silicon compound which is volatile at temperatures below those employed in the deposition process.
Claim 5
Dependent Claim
51 words
The method according to Claim 4, wherein said organometallic precursor is 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.
Claim 6
Dependent Claim
12 words
The method according to Claim 5, wherein said organometallic precursor is hexamethyldisilazane.
Claim 7
Dependent Claim
12 words
The method according to Claim 5, wherein said organometallic precursor is (dimethylamino)triethylsilane.
Claim 8
Dependent Claim
12 words
The method according to Claim 5, wherein said organometallic precursor is octamethyltrisiliazane.
Claim 9
Independent Claim
12 words
The method according to Claims 5, wherein said organometallic precursor is bis(dimethylamino)methylsilane.
Claim 10
Dependent Claim
29 words
The method according to Claim 2, wherein said inert or reducing gas is selected from the group consisting of nitrogen, argon, helium, methane, ethylene, ethane, hydrogen and mixtures thereof.
Claim 11
Dependent Claim
14 words
The method according to Claim 10, wherein said inert or reducing gas is nitrogen.
Claim 12
Dependent Claim
15 words
The method according to Claim 10, wherein said inert or reducing gas is methane/hydrogen mixtures.
Claim 13
Dependent Claim
22 words
The method according to Claim 10, wherein said inert or reducing gas is commercial process fuel gases which are derived from methane/ethylene/hydrogen/ethane.
Claim 14
Dependent Claim
26 words
The method according to Claim 2, wherein the concentration of said silicon organometallic precursor in said inert or reducing gas is less than 10.0 volume percent.
Claim 15
Dependent Claim
26 words
The method according to Claim 14, wherein the concentration of said silicon organometallic precursor in said inert or reducing gas is less than 5.0 volume percent.
Claim 16
Dependent Claim
22 words
The method according to Claim 2, wherein said process is thermal decomposition carried out at a temperature of between 600 and 1000°C.
Claim 17
Dependent Claim
14 words
The method according to Claim 16, wherein said temperature is between 700 and 900°C.
Claim 18
Dependent Claim
63 words
In an apparatus comprising at least one reactor tube which is subject to coking, the improvement being that said reactor tube is coated with a layer of a ceramic material consisting 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 19
Dependent Claim
20 words
The apparatus of Claim 18, wherein said reactor tube is a reactor tube used in steam or steamless hydrocarbon pyrolysis.
Claim 20
Dependent Claim
66 words
In a method of pyrolyzing a hydrocarbon, comprising pyrolyzing a hydrocarbon in at least one reactor tube, the improvement being that said reactor tube is coated with a layer of a ceramic material consisting 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.
References Cited (Backward Citations)
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