US2911293A

US2911293A - Production of gas

Info

Publication number: US2911293A
Application number: US587700A
Authority: US
Inventors: Prentiss S Viles
Original assignee: Exxon Research and Engineering Co
Current assignee: ExxonMobil Technology and Engineering Co
Priority date: 1956-05-28
Filing date: 1956-05-28
Publication date: 1959-11-03
Anticipated expiration: 1976-11-03
Also published as: GB857587A

Description

Nov. 3, 1959 P. S. VlLES PRODUCTION OF GAS Filed May 28, 1956 Prenf/'ss S. VIeS,

'TTORNEK PRODUCTION or GAS Prentiss S. Viles, Baytown, Tex., assignor, by mesne assignments, to Esso Research and Engineering Company, Elizabeth, NJ., a corporation of Delaware Application May 28, 1956, Serial No. 587,700

13 Claims. (Cl. 48-206) The present invention is directed to the production of gas from carbon. More particularly, the invention is concerned with the production of gas in a catalytic conversion operation from carbonaceous bodies. In itsmore specic aspects, the invention is directed to the production of carbon monoxide and hydrogen from carbon and carbonaceous bodies in contact with `a catalyst.

The invention may be briey described as involving the production of carbon monoxide and hydrogen by contacting a mixture of cobalt molybdate, water vapor, and carbon at a temperature in the range of 850 to 1600 F.

The carbon or carbonaceous material employed in the present invention may suitably be formed by reacting a hydrocarbon in the presence of cobalt molybdate ormay suitably be carbonaceous bodies, such as coal, coke, either formed from petroleum or from coal, lignite, tar, tar sands, carbonaceous shales, asphalts, andthe like. The amount of carbonaceous bodies employed with respect to the catalyst may range, from about 1.0 to about 50.0 percent on a weight basis with a preferred amount of about 10.0 percent by weight. The amount of steam employed to contact the catalyst and carbon mixture may suitably be about one mole of steam per mole of carbon, although lesser but sufficient amounts may be employed. v

The catalyst employed in the present invention is'suitably cobalt molybdate which isV actually a mixture of cobaltous oxide and molybdic trioxide. `The cobaltous oxide and molybdic trioxide are suitably in a ratio in the range from about 0.1 :1 Vto 1:0.1 on a mole basis.

The cobalt molybdatemay suitably be supported en il* a carrier base and examples thereof may include alumina, zirconia, magnesia, silica, silica-alumina, Filtrol, kieselguhr, Floridan, and the like. Preferred supports are pure alpha andgamma alumina. f

While purified cobalt molybdate may be used, the cobalt is preferably employed on a support of the type mentioned in an amount in the range from about 1.0 to about 25.0 weight percent with a preferred amount of about 15.0 weight percent of the total catalyst.

The temperatures employed in the practice of the present invention may suitably fall within the rangerof about 850 to about 1600 F. with a preferred temperature range of about 1100 to about 1400 F. Quite satisfactory results may be obtained at about 1300 F.

Low pressures are suitable in the practice of the present invention but the pressure may range from pounds absolute to about 1000 pounds per square inch gauge with a preferred pressure from about atmospheric to about 200 pounds per square inch gauge.

The invention may be practiced in various types of equipment. For example, a reaction zone may have a atentedy Nov. 3, 1959 f. ice

`conducting the operation.

The present invention will be further illustrated by refi erence to the drawing in which:

Fig. 1 is in the form of a flow diagram showing one mode of practicing the invention; and

Fig. 2 is in the form of a flow diagram showing a preferred mode wherein the uidized powder technique is employed.

Referring now to the drawing, numeral 11 designates a Y with carbonaceous bodies'. in this particular example, it

may be assumed that the cobalt molybdate catalyst has coke deposited therein and thereonin a manner which will be described hereinafter. The steam in contact with the catalyst 'and carbon mixture in reaction vzone 1S causes a reaction to proceed which results in the formation of a mixture of substantially pure carbon monoxide and hydrogen which is withdrawn from zone 18 by line 20 for useas may be desired.

To form carbon in and on the bed 19, the `flow of steam may beinterrupted by closing valve 12 and heavy hydrocarbons introduced into the system by line 21 controlled by, valve 22. The heavy hydrocarbons are heated in heater 14 and then deposited in the reaction zone 18 and allowed to undergo a coking reaction therein to de? posit coke in and on the catalyst. Thereafter the heavy hydrocarbons are no longer owed into zone 18 and aftercoking of the heavy hydrocarbons, the flow of steam is resumed to produce carbon monoxide and hydrogen.

Referring now to Fig.'2, a reaction zone 30 and a sepa.- 'ration zone 31are provided. .The reaction zone 30 is interconnected with the separation zone 31 by means of a transfer line 32 by way of which the cobalt molybdate catalyst is introduced from zone 31 into zone 30. The reaction zone 30 and separation zone 31 are also interconnected by means of a second transfer line 33 which serves to transfer catalyst and ashy or other contaminating bodies into the zone 31.

A hopper or other means for storing solid carbonaceous material, such as coal, is designated by the numeral 34 and is connected by a conduit 35 controlled by valve 36 withrtransfer line 32 which serves to introduce a mixture of coal and catalyst into line 32 and thence into reaction zone 30. 'Ille mixture of catalystrand coal, both ina finely divided form, is admixed with steam in transfer line 32 introduced by line 37 controlled by valve 38. This causes liuidization of the admixture ofcoal and catalyst and introduces same into zone 30 wherein a reaction takes place in aidense bed 39 therein to form hydrogen and carbon monoxide from the coal. Finely divided catalyst and other bodies are separated from the gaseous reaction product on passage through a separation zone 40 shown as -a cyclone separator but which may be any type of suitable separation zone. Cyclone separator 40 is provided with a dip leg 41 for return of catalyst and other bodies to the dense bed 39 While hydrogen and carbon monoxide from which the catalyst and other bodies have been separated are Withdrawn by line 42 for use as may be described.

The catalyst and other bodies, ksuch as ash and inert foreign material, overow into an annular space 43 dened by the wall of the reaction zone 30 and an annular member 44 and are Withdrawn by transfer line 33 and introduced thereby into separation zone 31, a uidizing medium being introduced into transfer line 33 by line 45 controlled b`y Valve 46. A suitable uidizing medium may include inert gas, flue gas, steam, recycle gas from vessel 31, and the like materials.

In separation zone 30, the catalyst which may have a specific gravity of about 3.5 to 4.0 is separated from the ashy bodies and other inert material which may have a specific gravity of about 1.5 to 3.0. The inert materials and ashy bodies separated from the catalyst overow into a funnel member 47 and may be withdrawn through line 52 and discarded. The catalyst by virtue of having a higher gravity than the ashy inert material ltends to accumulate in the bottom of separation zone 31 and is discharged into line 32 for recycling to reaction zone 30. The uidizing gas is withdrawn from separation zone 31 by line 48 after removal of catalyst and inert material therefrom in a separation zone 49 which may suitably be a single or a plurality of cyclone separators, each provided with a dip leg 50 for returning the catalyst and inert material to bed 51 in zone 31.

The mixture of carbon monoxide and hydrogen produced in the present invention is very useful and may be used as a synthesis gas for Lthe Fischer-Tropsch reaction, as a feed gas in the so-called Oxo synthesis, and as a gas for producing metallic carbonyls by reacting the 1 carbon monoxide and hydrogen with suitable metals such as nickel, iron, and the like.

While a method for separating ash and inert solids from carbonaceous materials is shown, the ash and inert solids may be separated by Well-known mechanical means such as screens, vibrators, and the like by way of which one solid is separated from another solid.

In the practice of the present invention, it is desirable that the cobalt molybdate, either as such or supported on a carrier, have a particle diameter in the range from about 120 to more than 1000 microns with a major amount in the range from about 150 to 250 microns. A Likewise, the solid carbonaceous material should have suitable particle diameters in the range from about 1.0 to about 120 microns with a major amount having a particle diameter in the range from about 20 to about 120 microns to allow ready uidization thereof. It is desired that the cobalt molybdate either alone or preferably supported on gamma alumina and the like be of such a size that the smallest particle is larger than the largest particle of the solid carbonaceous material.

It is also desirable that the supported catalyst be in a form designed to resist attrition. Spherical catalytic bodies of the particle sizes indicated are desirable as attrition resistant bodies.

p Carbon monoxide and hydrogen have been produced by contacting a bed of cobalt molybdate containing carbonaceous bodies dispersed therein with steam at a temperature of l300 F. to produce a mixture of carbon monoxide and hydrogen. In these runs, nitrogen saturated with water vapor at 78 F. and atmospheric pressure was contacted at 1300 F. and atmospheric pressure with 1a-inch pills of a supported cobalt molybdate catalyst admixed with 20 percent by weight of iinely pulverized petroleum coke. The conditions for and results of these runs are presented in the following table:

Table I Product Hours ou Operation Charge Rate, V./V./Hr Mol Percent:

Carbon Dioxide.

Propylene Propan e Iso-Butane N-Nutane Butylenes Iso-Pentane N -Pentane Pentylenas Cyclopentane and Heavier These data show that water vapor reacts with petroleum coke in the presence of cobalt molybdate at elevated temperatures to produce hydrogen and carbon oxides, specifically carbon monoxide. It'is of interest to note that larger than stoichiometric quantities of hydrogen appeared in the product. Also, it is to be noted that best results were obtained at a space velocity of 80 v./v./hour.

While these operations were conducted employing an inert gas saturated with water vapor, it is to be understood that other carriers for the water vapor may be used and that steam alone may be employed.

This application contains subject matter common to Serial No. 587,566, entitled Method of Making Hydrogen and Serial No. 587,699, entitled Treatment vof Hydrocarbons, both led May 28, 1956, for Prentiss S. Viles.

The nature and objects of the present invention having been completely described and illustrated, what I Wish to claim as new and useful and to secure by Letters Patent is:

l. A method for producing carbon monoxide and hydrogen which comprises contacting a mixture of a catalytic amount of cobalt molybdate and amorphous carbon witha gaseous charge stream containing vaporized water as the sole reactant while maintaining a temperature within the range of 850 F. to l600 F., and recovering said carbon monoxide and hydrogen.

2. A method for producing carbon monoxide and hydrogen which comprises suspending a mixture of a catalytic amount of finely divided cobalt molybdate and amorphous carbon in a conversion zone in a gaseous charge stream consisting essentially of steam while mainf taining a temperature in said zone within the range of 850 F. to l600 F., and recovering said carbon mon# oxide and hydrogen.

3. A method for producing carbon monoxide and hydrogen which comprises passing a charge stream consisting essentially of vaporized water through a conver# sion zone containing a xed bed of a catalytic amount of cobalt molybdate having amorphous carbon finely dispersed therein while maintaining in said zone a temperature within the range of about 850 F. to 1600 F., and recovering said carbon monoxide and hydrogen.

4. A continuous method for producing carbon monoxide and hydrogen which comprises continuously suspending a catalytic amount of nely divided cobalt molybdate and amorphous carbon in a gaseous charge stream consisting essentially of steam while maintaining within said zone a temperature within the range of 850 F. to 1600" F. and a pressure Within the range of 0 pounds absolute to 1000 pounds per equare inch gauge to form hydrogen and carbon monoxide, recovering said hydrogen, carbon monoxide and cobalt molybdate exteriorly of said zone and recycling said recovered cobalt molybdate to said zone in admixture with fresh amorphous carbon, and recovering said carbon monoxide and hydrogen.

5. A method as in claim 4 wherein the amorphous carbon is coal.

6. A method as in claim 4 wherein the amorphous carbon is coke.

l. A method as in claim 4 wherein the amorphous carbon is lignite. Y

8. A method as in claim 4 wherein the amorphous carbon istar sand.

9. A method as in claim 4 wherein the amorphous carbon is carbonaceous shale.

10. A method as in claim 4 wherein the cobalt molybdate is supported on a carrier base.

1l. A method as in claim 4 wherein the amorphous carbon comprises asphaltic bodies.

12. A method for producing carbon monoxide and hydrogen which comprises heating a mixture consisting essentially of steam, amorphous carbon and a catalytic amount of cobalt molybdate to a temperature of about 1100 F. to 1400 F., and recovering said carbon monoxide and hydrogen.

13. A method for producing carbon monoxide and hydrogen which comprises heating a mixture consisting essentially of steam, amorphous carbon and a catalytic amount of cobalt molybdate to a temperature of about 1100 F. to 1400 F., at a pressure of about 0 to 200 p.s.i.g., said mixture containing about 1 to 50 weight percent of amorphous carbon and about one mol of steam per mol of amorphous carbon, and recovering said carbon monoxide and hydrogen.

References Cited in the le of this patent UNITED STATES PATENTS 2,393,288 Byrns Jan. 22, 1946 2,440,236 Stirton Apr. 27, 1948 2,643,939 Porter June 30, 1953 2,652,319 Sweetster Sept. 15, 1953 2,694,623 Welty Nov. 16, 1954 FOREIGN PATENTS 613,423 Great Britain Nov. 12, 1948

Claims

12. A METHOD FOR PRODUCING CARBON MONOXIDE AND HYDROGEN WHICH COMPRISES HEATING A MIXTURE CONSISTING ESSENTIALLY OF STREAM, AMORPHOUS CARBON AND A CATALYTIC AMOUNT OF COBALT MOLYBDATE TO A TEMPERATURE OF ABOUT 1100* F, TO 1400* F., AND RECOVERING SAID CARBON MONOXIDE AND HYDROGEN.