US4483691A — Production of synthetic natural gas from coal gas…

Claim 1

Independent Claim 369 words

In a coal gasification process in which coal is reacted with steam and oxygen to produce (i) a gasifier synthesis gas which is methanated to produce a synthetic natural gas, and (ii) a liquid hydrocarbon by-product, the improvement comprising preparing a secondary synthesis gas from said liquid hydrocarbon by-product and methanating the secondary synthesis gas, by the steps of: (a) preheating an inlet stream comprising said liquid hydrocarbon by-product, H 2 O, and oxygen to a preheat temperature at least sufficiently high to initiate catalytic oxidation of said hydrocarbon by-product as defined below, but less than about 1200° F. (649° C.); (b) introducing the preheated inlet stream into a first catalyst zone comprising a monolithic body having a plurality of gas flow passages extending therethrough and having a catalytically effective amount of a platinum and palladium catalytic component dispersed therein, the amounts of hydrocarbon by-product, H 2 O and oxygen introduced into said first catalyst zone being controlled to maintain an H 2 O to C ratio of from about 0.5 to 5 and an O 2 to C ratio of from about 0.15 to 0.4 in said inlet stream; (c) contacting the preheated inlet stream within said first catalyst zone with said platinum and palladium catalytic component to initiate and sustain therein catalytic oxidation of a quantity, less than all, of said hydrocarbon by-product sufficient to attain a temperature within said first catalyst zone at least high enough to crack substantially all unoxidized C 5 or heavier hydrocarbons in said by-product to C 1 to C 4 hydrocarbons, the temperature of at least a portion of said monolith being at least about 250° F. (139° C.) greater than the ignition temperature of said inlet stream, but not more than about 2000° F. (1093° C.), whereby to produce a first catalyst zone effluent comprising primarily methane, hydrogen, carbon monoxide, carbon dioxide and H 2 O and C 2 -C 4 hydrocarbons; (d) passing said effluent to a treatment zone for the removal of carbon dioxide and water therefrom; (e) withdrawing the treated first catalyst zone effluent as a secondary synthesis gas; and (f) methanating said gasifier synthesis gas and said secondary synthesis gas to provide therefrom synthetic natural gas.

Claim 2

Dependent Claim 369 words

In a coal gasification process in which coal is reacted with steam and oxygen to produce (i) a gasifier synthesis gas which is methanated to produce a synthetic natural gas, and (ii) a liquid hydrocarbon by-product, the improvement comprising preparing a secondary synthesis gas from said liquid hydrocarbon by-product and methanating the secondary synthesis gas, by the steps of: (a) preheating an inlet stream comprising said liquid hydrocarbon by-product, H 2 O, and oxygen to a preheat temperature at least sufficiently high to initiate catalytic oxidation of said hydrocarbon by-product as defined below, but less than about 1200° F. (649° C.); (b) introducing the preheated inlet stream into a first catalyst zone comprising a monolithic body having a plurality of gas flow passages extending therethrough and having a catalytically effective amount of a platinum and palladium catalytic component dispersed therein, the amounts of hydrocarbon by-product, H 2 O and oxygen introduced into said first catalyst zone being controlled to maintain an H 2 O to C ratio of from about 0.5 to 5 and an O 2 to C ratio of from about 0.15 to 0.4 in said inlet stream; (c) contacting the preheated inlet stream within said first catalyst zone with said platinum and palladium catalytic component to initiate and sustain therein catalytic oxidation of a quantity, less than all, of said hydrocarbon by-product sufficient to attain a temperature within said first catalyst zone at least high enough to crack substantially all unoxidized C 5 or heavier hydrocarbons in said by-product to C 1 to C 4 hydrocarbons, the temperature of at least a portion of said monolith being at least about 250° F. (139° C.) greater than the ignition temperature of said inlet stream, but not more than about 2000° F. (1093° C.), whereby to produce a first catalyst zone effluent comprising primarily methane, hydrogen, carbon monoxide, carbon dioxide and H 2 O and C 2 -C 4 hydrocarbons; (d) passing said effluent to a treatment zone for the removal of carbon dioxide and water therefrom; (e) withdrawing the treated first catalyst zone effluent as a secondary synthesis gas; and (f) methanating said gasifier synthesis gas and said secondary synthesis gas to provide therefrom synthetic natural gas.

Claim 3

Dependent Claim 89 words

The process of claim 1 further including the step of passing said first catalyst zone effluent, while still at an elevated temperature, from said first catalyst zone to a second catalyst zone containing a steam reforming catalyst therein, and contacting the first zone effluent in said second catalyst zone with said steam reforming catalyst to react hydrocarbons therein with H 2 O to produce hydrogen and carbon oxides therefrom, and then passing the effluent of said second catalyst zone as said effluent to said treatment zone of step (d).

Claim 4

Dependent Claim 27 words

The process of claim 1 wherein at least about 50% by weight of said hydrocarbon by-product is converted to C 1 hydrocarbons in said first catalyst zone.

Claim 5

Dependent Claim 32 words

The process of claim 2 wherein a total of at least about 98% by weight of said hydrocarbon by-product is converted to C 1 hydrocarbons in said first and second catalyst zones.

Claim 6

Dependent Claim 16 words

The process of claim 2 wherein said steam reforming catalyst comprises a platinum group metal component.

Claim 7

Dependent Claim 25 words

The process of claim 1 or claim 2 wherein the temperature of said first catalyst zone effluent is at least about 1,400° F. (760° C.).

Claim 8

Dependent Claim 30 words

The process of claim 1 or claim 2 wherein said secondary synthetic natural gas is combined with said gasifier synthetic natural gas to provide a combined product synthetic natural gas.

Claim 9

Dependent Claim 25 words

The process of claim 1 or claim 2 wherein the preheat temperature is from about 800° F. to 1200° F. (427° C. to 649° C.).

Claim 10

Dependent Claim 45 words

The process of claim 2 wherein said first catalyst zone is maintained at a temperature of from about 1400° F. to 2000° F. (760° C. to 1093° C.) and the first zone effluent is introduced into said second catalyst zone at substantially the same temperature.

Claim 11

Dependent Claim 31 words

The process of claim 1 or claim 2 wherein a volumetric hourly rate of at least 100,000 volumes of throughput per volume of catalyst is maintained in said first catalyst zone.

Claim 12

Dependent Claim 53 words

The process of claim 2 wherein a volumetric hourly rate of at least 100,000 volumes of throughput per volume of catalyst is maintained in said first catalyst zone and a volumetric hourly rate of from about 2,000 to 20,000 volumes of throughput per volume of catalyst is maintained in said second catalyst zone.

Claim 13

Dependent Claim 49 words

The process of claim 1 or claim 2 wherein said platinum and palladium catalytic component of said first catalyst zone comprises a catalytically effective amount of palladium and platinum catalytic component and, optionally, rhodium catalytic component distended upon a refractory metal oxide support layer carried on said monolithic body.

Claim 14

Dependent Claim 35 words

The process of claim 12 wherein said catalytic components of said first catalyst zone comprise, on an elemental metal basis, about 10 to 90% by weight palladium and about 90 to 10% by weight platinum.

Claim 15

Dependent Claim 30 words

The process of claim 13 wherein said catalytic components of said first catalyst zone comprise about 25 to 75% by weight palladium, and about 75 to 25% by weight platinum.

Claim 16

Dependent Claim 28 words

The process of claim 2 wherein said steam reforming catalyst comprises a catalytically effective amount of rhodium and platinum catalytic components distended upon a refractory metal oxide support.

Claim 17

Dependent Claim 35 words

The process of claim 15 wherein said catalytic components of said steam reforming catalyst comprises, on an elemental metal basis, about 10 to 90% by weight rhodium, and about 90 to 10% by weight platinum.

Claim 18

Dependent Claim 30 words

The process of claim 16 wherein said catalytic components of said steam reforming zone comprise about 20 to 40% by weight rhodium and about 80 to 60% by weight platinum.

Claim 19

Dependent Claim 23 words

The process of claim 1 or claim 2 or claim 3 carried out at a pressure of from about 50 to 1500 psig.

Claim 20

Dependent Claim 316 words

In a coal gasification process in which coal is reacted with steam and oxygen to produce a gasifier synthesis gas and liquid hydrocarbon by-product, the improvement comprising preparing a secondary synthesis gas from said liquid hydrocarbon by-product by the steps of: (a) preheating an inlet stream comprising said liquid hydrocarbon by-product, H 2 O and oxygen to a preheat temperature of from about 800° F. to 1200° F. (427° C. to 649° C.); (b) introducing the preheated inlet stream into a first catalyst zone comprising a monolithic body having a plurality of gas flow passages extending therethrough and comprising a catalytically effective amount of palladium and platinum catalytic components dispersed therein, the amounts of hydrocarbon by-product, H 2 O and oxygen introduced into said first catalyst zone being controlled to maintain an H 2 O to C ratio from about 0.5 to 5 and an O 2 to C ratio of from about 0.15 to 0.4 in said inlet stream; (c) contacting the preheated inlet stream within said first catalyst zone with said palladium and platinum catalytic components at a volumetric hourly rate of at least about 100,000 volumes of throughput per volume of catalyst per hour to initiate and sustain therein catalytic oxidation of a quantity, less than all, of said hydrocarbon by-product sufficient to attain a temperature within said first catalyst zone of from about 1400° F. to 2000° F. (760° C. to 1093° C.) and cracking substantially all unoxidized C 5 or heavier hydrocarbons in said by-product to a mixture of C 1 to C 4 hydrocarbons and predominating in C 1 hydrocarbons, whereby to produce a first catalyst zone effluent comprising methane, hydrogen, carbon monoxide, carbon dioxide and H 2 O; (d) passing said effluent to a treatment zone for the removal of carbon dioxide and water therefrom; and (e) withdrawing the treated first catalyst zone effluent as a secondary synthesis gas.

Claim 21

Dependent Claim 316 words

In a coal gasification process in which coal is reacted with steam and oxygen to produce a gasifier synthesis gas and liquid hydrocarbon by-product, the improvement comprising preparing a secondary synthesis gas from said liquid hydrocarbon by-product by the steps of: (a) preheating an inlet stream comprising said liquid hydrocarbon by-product, H 2 O and oxygen to a preheat temperature of from about 800° F. to 1200° F. (427° C. to 649° C.); (b) introducing the preheated inlet stream into a first catalyst zone comprising a monolithic body having a plurality of gas flow passages extending therethrough and comprising a catalytically effective amount of palladium and platinum catalytic components dispersed therein, the amounts of hydrocarbon by-product, H 2 O and oxygen introduced into said first catalyst zone being controlled to maintain an H 2 O to C ratio from about 0.5 to 5 and an O 2 to C ratio of from about 0.15 to 0.4 in said inlet stream; (c) contacting the preheated inlet stream within said first catalyst zone with said palladium and platinum catalytic components at a volumetric hourly rate of at least about 100,000 volumes of throughput per volume of catalyst per hour to initiate and sustain therein catalytic oxidation of a quantity, less than all, of said hydrocarbon by-product sufficient to attain a temperature within said first catalyst zone of from about 1400° F. to 2000° F. (760° C. to 1093° C.) and cracking substantially all unoxidized C 5 or heavier hydrocarbons in said by-product to a mixture of C 1 to C 4 hydrocarbons and predominating in C 1 hydrocarbons, whereby to produce a first catalyst zone effluent comprising methane, hydrogen, carbon monoxide, carbon dioxide and H 2 O; (d) passing said effluent to a treatment zone for the removal of carbon dioxide and water therefrom; and (e) withdrawing the treated first catalyst zone effluent as a secondary synthesis gas.

Claim 22

Dependent Claim 124 words

The process of claim 19 further including the step of passing said first catalyst zone effluent, while still at a temperature of from about 1400° F. to 2000° F. (760° C. to 1093° C.) from said first catalyst zone to a second catalyst zone containing a platinum group metal steam reforming catalyst therein, and contacting the first zone effluent in said second catalyst zone with said steam reforming catalyst at a volumetric hourly rate of from about 2,000 to 20,000 volumes of throughput per volume of catalyst per hour to react hydrocarbons therein with H 2 O to produce hydrogen and carbon oxides therefrom, and then passing the effluent of said second catalyst zone as said effluent to said treatment zone of step (d).

Claim 23

Dependent Claim 27 words

The process of claim 19 wherein at least about 50% by weight of said hydrocarbon by-product is converted to C 1 hydrocarbons in said first catalyst zone.

Claim 24

Dependent Claim 32 words

The process of claim 20 wherein a total of at least about 98% by weight of said hydrocarbon by-product is converted to C 1 hydrocarbons in said first and second catalyst zones.

Claim 25

Dependent Claim 35 words

The process of claim 19 or claim 20 wherein said first catalyst zone comprises palladium and platinum and, optionally, rhodium catalytic components distended upon a refractory metal oxide support layer carried on said monolithic body.

Claim 26

Dependent Claim 34 words

The process of claim 23 wherein said catalytic components of said first catalyst zone comprise, on an elemental metal basis, about 10 to 90% by weight palladium, and 90 to 10% by weight platinum.

Claim 27

Dependent Claim 28 words

The process of claim 24 wherein said catalytic components of said first catalyst comprise about 25 to 75% by weight palladium and 75 to 25% by weight platinum.

Claim 28

Dependent Claim 23 words

The process of claim 20 wherein said steam reforming catalyst comprises platinum and rhodium catalytic components distended upon a refractory metal oxide support.

Claim 29

Dependent Claim 33 words

The process of claim 26 wherein said catalytic components of said second catalyst zone comprise, on an elemental basis, about 10 to 90% by weight rhodium and 90 to 10% by weight platinum.

Claim 30

Dependent Claim 29 words

The process of claim 27 wherein said catalytic components of said second catalyst zone comprise about 20 to 40% by weight rhodium and 80 to 60% by weight platinum.

Claim 31

Dependent Claim 33 words

The process of claim 19 or claim 20 further including treating said liquid hydrocarbon by-product to remove solids, metals, and heavy tar therefrom prior to passing said by-product to said first catalyst zone.

Claim 32

Dependent Claim 17 words

The process of claim 29 further including methanating said secondary synthesis gas and said gasifier synthesis gas.

Claim 33

Dependent Claim 30 words

The process of claim 25 wherein said catalytic components of said first catalyst zone comprise about 40 to 60% by weight palladium, and about 60 to 40% by weight platinum.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1987-11-20	1988-05-21	1988-11-20	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1991-11-20	1992-05-21	1992-11-20	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1995-11-20	1996-05-21	1996-11-20	$7700.00	Window Closed / Lapsed

Production of synthetic natural gas from coal gasification liquid by-products

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