EP0004456A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Methanation of carbon monoxide without prior separation of inert gases
Assignee: Union Carbide Corp
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Filing: 1979-03-21
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Granted: —
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Expires: 1999-03-21
Abstract
Abstract Carbon monoxide-containing gas streams are passed over a catalyst capable of catalyzing the disproportionation of carbon monoxide so as to deposit a surface layer of active surface carbon on the catalyst substantially without formation of inactive coke thereon. The surface layer is contacted with steam and is thus converted to methane and CO 2 , from which a relatively pure methane produce may be obtained. Dilute carbon monoxide-containing streams, as from underground coal gasification with air or the effluent from blast furnace operations, can be used without pretreatment to concentrate the carbon monoxide and/or to separate inert gases therefrom. Conversion of the active surface carbon with high pressure steam enables a high pressure product methane stream to be generated without expensive compression equipment and high energy consumption. Nickel, cobalt, iron, ruthenium. rhenium and alloys thereof are preferred catalyst, with the surface area thereof being preferably at least about 10 m 2 / gm. Conversion of the active surface carbon can also be accomplished by contact with hydrogen. Carbon monoxide-containing streams having hydrogen or water present therein can be used, with only the carbon monoxide available after reaction with said hydrogen or water being decomposed to form said active surface carbon. The hydrogen or water will be converted, partially or completely, to methane which can be utilized in a combustion zone to generate heat for steam production or other energy recovery purposes.
Inventors
- 👤 Jule Anthony Rabo
- 👤 Louis Frank Elek
- 👤 James Nelson Francis
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 06:27
CPC Classifications
C; C07; C07C; C07C9/00; C07C9/02; C07C9/04; C07C1/00; C07C2521/00; C07C2521/02; C07C2521/04; C07C2521/06; C07C2521/08; C07C2523/00; C07C2523/12; C07C2523/16; C07C2523/32; C07C2523/36; C07C2523/38; C07C2523/40; C07C2523/46; C07C2523/70; C07C2523/74; C07C2523/745; C07C2523/75; C07C2523/755; Y; Y02; Y02P; Y02P20/00; Y02P20/10
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
165 words
A process for the production of methane from a carbon monoxide-containing gas stream comprising: (a) passing a carbon monoxide-containing gas stream over a catalyst capable of catalysing the disproportionation of carbon monoxide, the carbon monoxide thereby being decomposed to form carbon dioxide and an active surface carbon that is deposited on the catalyst, the gas stream being passed over the catalyst for a time sufficient to deposit a surface layer of the active surface carbon on the catalyst substantially without the subsequent formation of inactive coke thereon; (b) contacting the layer of active surface carbon deposited on the catalyst with (a) steam or a steam-containing gas stream or (b) hydrogen or a hydrogen-containing gas stream, thereby converting the active surface carbon to methane and carbon dioxide, whereby relatively pure methane can conveniently be produced from carbon monoxide-containing gas streams without the necessity for the prior concentration of the carbon monoxide and/or the separation thereof from inert gases that may be present in the gas stream.
Claim 2
Dependent Claim
165 words
A process for the production of methane from a carbon monoxide-containing gas stream comprising: (a) passing a carbon monoxide-containing gas stream over a catalyst capable of catalysing the disproportionation of carbon monoxide, the carbon monoxide thereby being decomposed to form carbon dioxide and an active surface carbon that is deposited on the catalyst, the gas stream being passed over the catalyst for a time sufficient to deposit a surface layer of the active surface carbon on the catalyst substantially without the subsequent formation of inactive coke thereon; (b) contacting the layer of active surface carbon deposited on the catalyst with (a) steam or a steam-containing gas stream or (b) hydrogen or a hydrogen-containing gas stream, thereby converting the active surface carbon to methane and carbon dioxide, whereby relatively pure methane can conveniently be produced from carbon monoxide-containing gas streams without the necessity for the prior concentration of the carbon monoxide and/or the separation thereof from inert gases that may be present in the gas stream.
Claim 3
Dependent Claim
76 words
A process according to claim 1 in which decomposition of carbon monoxide and the conversion of active surface carbon to methane takes place at a temperature of about 100° to about 400°C and a pressure of about 1 to about 100 atmos, the methane produced being at least about 50% of the stoichiometric amount, the carbon thus recovered in the form of methane being at least about 12.5% of the carbon in the carbon dioxide decomposed.
Claim 4
Dependent Claim
37 words
A process according to claim 1 or 2 in which the gas stream passed over the disproportionation catalyst contains from about 5% to about 50% by volume carbon monoxide and at least about 5% by volume nitrogen.
Claim 5
Dependent Claim
46 words
A process according to any one of claims 1 to 3 in which the carbon monoxide decomposition temperature is from about 200°C to about 300°C and in which the conversion of active surface carbon by steam is at a temperature from about 200°C to about 350°C.
Claim 6
Dependent Claim
57 words
A process according to any one of claims 1 to 4 in which the active surface carbon conversion is carried out at a pressure of from about 100 to about 500 psi,the use of high pressure steam permitting the generation of a high-pressure product gas stream without the need for expensive compression equipment and high energy consumption.
Claim 7
Dependent Claim
53 words
A process according to any one of claims 1 to 5 in which the carbon monoxide-containing gas stream is passed over the catalyst until CO breakthrough occurs in the gaseous effluent from the carbon monoxide decomposition reaction, thereby enhancing the amount of active surface carbon deposited while minimizing undesired formation of inactive coke.
Claim 8
Dependent Claim
26 words
A process according to any one of claims 1 to 6 in which the catalyst is selected from nickel, cobalt, iron, ruthenium, rhenium and alloys thereof.
Claim 9
Dependent Claim
25 words
A process according to claim 7 in which the catalyst comprises nickel having a surface area of at least about 2 5 m 2 /gm.
Claim 10
Dependent Claim
60 words
A process according to any one of claims 1 to 8 in which the catalyst is mixed with a catalyst support additive in the amount of from about O.1 to about 50% by weight based on the weight of the catalyst composition mixture of catalyst and additive, the catalyst having a surface area of at least about 1 0 m2/gr.
Claim 11
Dependent Claim
20 words
A process according to claim 9 in which the additive is selected from zirconia, thoria, alumina, silica and mixtures thereof.
Claim 12
Dependent Claim
58 words
A process according to claim 10 in which the additive comprises zirconia and alumina, the zirconia and alumina each being employed in an amount within the range of from about 3% to about 30% by weight, with the combination being employed in an amount up to about 50% by weight, based on the weight of the catalyst composition.
Claim 13
Dependent Claim
45 words
A process according to claim 9, 10 or 11 in which the catalyst support additive comprises the hydroxide or carbonate thereof coprecipitated with the hydroxide or carbonate of the catalyst prior to the reduction of the catalyst hydroxide or carbonate to the active catalyst state.
Claim 14
Dependent Claim
47 words
A process according to any one of claims 9 to 12 in which the catalyst composition is mixed with a binding agent in an amount within the range of from about 5% to about 40% by weight based on the total weight of the catalyst composition-binder mixture.
Claim 15
Dependent Claim
73 words
A process according to any one of claims 1 to 13 in which the carbon monoxide-containing gas stream contains hydrogen or water, the hydrogen or water being converted to methane upon passage of the gas stream over the catalyst, the methane being vented from the catalyst having the surface layer of active surface carbon deposited thereon together with the carbon dioxide and any inert gases that may be present in the gas stream.
Claim 16
Dependent Claim
22 words
A process according to claim 14 including subjecting the vented methane to combustion in a com- budion zone for heat generation purposes.
Claim 17
Dependent Claim
29 words
A process according to claim 15 in which the heat is employed for steam generation purposes, the steam being utilized for the conversion of active surface carbon to methane.
Claim 18
Dependent Claim
46 words
A process according to any one of claims 1 to 16 in which the carbon monoxide-containing gas stream comprises the effluent from the underground gasification of coal with air, the effluent from blast furnace operations, or the raw synthesis gas from the oxygen-blown gasification of coal.
Claim 19
Dependent Claim
20 words
A process according to any one of claims 1 to 17 including separating relatively pure methane from the carbnn dioxide.
References Cited (Backward Citations)
US2544574A
Cited
US3511624A
Cited
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