CA1062285A - Conversion of synthesis gas to hydrocarbon mixtures - Google Patents

Abstract

CONVERSION OF SYNTHESIS GAS TO HYDROCARBON MIXTURE

ABSTRACT OF THE DISCLOSURE

Contacting a mixture of carbon monoxide and hydrogen with a mixture of a carbon monoxide reduction catalyst, such as a Fischer-Tropsch catalyst or a methanol synthesis catalyst, and a crystalline aluminosilicate to produce hydrocarbon mixtures useful in the manu-facture of heating fuels, high octane gasoline, aromatic hydrocarbons, and chemical intermediates.

Description

106228~;

BACKGFOUND OF THE INVENTION

8551 Field of the Invention This invention is concerned with an improved process for converting synthesis gas~ i.e., mixtures of gaseous carbon oxides with hydrogen or hydrogen donors, to hydrocarbon mixtures.
Processes for the conversion of coal and other hydrocarbons such as natural gas to a gaseous mixture consisting essentially of hydrogen and carbon monoxide and/or dioxlde are well known. Those of m3~or lmportance depend either on the partial combustion of the fuel with an oxygen-containing gas or on the high temperature reaction of the fuel with steam, or on a com-. bination of these two reactions. An excellent summary of the art of gas manufacture, including synthesis gas, from solld and llquid fuels, ls given in Encylcophedia of Chemical Technology, Edited by Klrk-Othmer, Second Edition, . . .
: Volume 10, pages 353-433, (1966), Interscience Publlshers, New York, New York.
It ls also well known that synthesls gas will undergo converslon - to reduction products of carbon monoxlde, such as hydrocarbons, at from about . .
300F to about 850F, under from about one to one thousand atmospheres pressure,over a fairly wide varlety of catalysts. The Fischer-Tropsch process, for example, which has been most extenslvely studled, produces a range of liquid hydrocarbons, a portion of which have been used as low octane gasoline.
- Catalysts that have been studled for this and related processes include those based on iron, cobalt, nickel, ruthenlum, thorlum, rhodium and osmium, or their . oxldes.
It has however not yet proved posslble to identify any combination of .~
, 25 catalyst and processing conditions which will yleld liquid hydrocarbons in the gasoline boiling range which contain highly branched paraffins and substantial quantities of aro~atic hydrocarbons, both of which are requlred for high quality gasoline; or to selectlvely produce aromatlc hydrocarbons particularly . . ~

rich in the benzene to xylenes range~ A review of the status of this art is given in "Carbon Monoxide-Hydrogen Reactions", Encyclopedia of Chemical Technology, Edited by Kirk-Othmer, Second Edition, Volume 4, pp. 446-488, Interscience Pub-lishers, New York, N.Y.
Recently it has been discovered that synthesis gas may be converted to oxygenated organic compounds and these compounds then converted to higher hydrocarbons, particularly high octane gasoline, by catalytic contact of the synthesis gas with a carbon monoxide reduction catalyst followed by con-tacting the conversion products so produced with a special type of zeolite catalyst in a separate reaction zone. m is two-stage conversion is described in German published application

2,438,252.
It has now been discovered that valuable hydrocarbon mixtures may be produced directly by reacting synthesis gas, i.e., mixtures of hydrogen and carbon monoxide, together pos-sibly with other carbon oxides, or the equivalen of such , .: . .
mixtures, in the presence of certain heterogeneous catalysts comprising intimate mixtures of two or more components.
According to the invent~on, therefore, a process for producing hydrocarbons from synthesis gas comprises con-tacting such gas, at a temperature within the range o 450 to 1000F., with a catalyst comprising a mixture of a metal i ~ .
,, or metal compound characterized by catalytic activity for ~ the reduction of carbon monoxide and a crystalline alumino--~ silicate having a pore diameter greater than about 5 Angstroms, a silica to alumina ratio of at least 12, and a constraint index -within the range of 1 to 12 and recovering gasoline boiling range hydrocarbons.
` The metal, or metal compound, typically comprises from 0.1 to 99, preferably from about one weight percent to about ~ - 2 -- .
. . .., . . . ,~ . ., , .... . . ...., ~ -.

~` 1062285 eighty weight percent, of the mixture~ The carbon monoxide reduction component and the crystalline aluminosilicate may be in the same or separate particles.

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The preferred crystalline aluminosilicates are ZSM-5, ZSM-ll, ZSM-12, ZSM}35 and ZSM-38. The preferred metals are those of group 8, but metals from groups lB (e.g. copper), IIB (e.g. zinc) and/or IIIB (e.g. thorlum),and thelr compounds, may yleld excellent results. Mixtures of all of these, together with promoters such as chromia, are of value.
The ratio of carbon monoxide reduction component to crystalline aluminosilicate may be ad~usted to control product character, l.e. to determine - whether gasoline boiling range components, paraffins/aromatics or internal olefins predomlnate.
me hydrogen to carbon oxides volume ratio is advantageously main-tained within the range of from 0.2 to 6.o.
Depending on the choice of components and the particular reaction conditions employed, one may obtain substantial quantities of liquid mixtures which are rich in one or more olefins, branched paraffins, and aromatic hydro-y 15 ~arbons and are eminently suited for making high octane gasoline or petrochemicals.
Thus, one may select catalyst and operating conditions to produce normally gaseous hydrocarbons having at least one carbon-to-carbon bond as the predo-minant product, or hydrocarbon streams rich in internal olefins. Such products have value as petrochemical feedstocks, and for the manufacture of liquefiable petroleum fuel. The catalysts employed not only produce highly desirable products with good selectivity but in many cases produce them either with extraordinarily high conversion per pass, or under mild conditions, or some-times both. With thoria as the carbon monoxide reducing component, synthesis ~: gas is converted at surprisingly low temperature and pressure. With a methanol ;?~, 25 synthesis catalyst of the zinc-copper-chromite-type as the reducing component, i~; synthesis gas conversion rate is increased and large proportions of hydrocarbons -. having at least one carbon-to-carbon bond are obtained instead of methanol.
With Fischer-Tropsch-type catalysts, increased quantities of aromatic hydro-carbons are obtained. Furthermore, when the preferred crystalline alumino-t . . .

.

~ :106ZZ85 sllicate co~ponent iia ~sed the catalytic actlvity ls sustained for unusually lon~ periods Or tin~ and aromatic hydrocarbons, when produced, are very rich in toluene and xylenes.
A typical purified synthesis g~s will have the following volume compositlon , on a water-free basis: hydrogen~ 51; carbon dioxide, 40; carbon dioxide, 4; methane, 1; and nitrogen, 4.
The synthesis gas may be prepared from fossll fuels by any Or the known methods, including such in sltu gasification processes as the underground partial combustion of coal and petroleum deposlts.
- 10 The term fossil fuels, as used herein, is intended to include anthra-cite and bituminous coal, lignite, crude petroleum, shale oil, oil ` from tar sands, natural gas, as sell as fuels derived from simple - physical separations or n;ore profound transformations of these ~r~ materials, including coXed coal, petroleum coke, gas oil, residua . ~,. , from petroleum distillation, and two or more of any of the foregoing - materlals in co~bination. Other carbonaceous fuels such as peat, :~ - wood and cellulosic waste materials also may be used.
,~
The raw synthesis gas produced frcm fossil fuels will contain various i~purities such as particulates, sulfur, ald metal carbonyl compounds, and will be characterized by a hydrogen-to-carbon oxides ratio which will depend on the fossll fuel and the particular gasification technology utilized. In general, it is desirable for the efficiency of subsequent conversion steps to purify the raw synthesis ; gas by the removal of impurities. Techniques for such purification ., , j 25 are known and are not part of this invention. However, it may not be necessary to remove substantially all the sulfur impurities when thoria -l is used as the carbon monoxide reducing component, since thoria is not irreversably poisoned by sulfur compounds. Fhrthermore, should it be required, it is preferred to adjust the hydrogen-to-carbon oxide volume ~i 3 ratio to be within the range of from 0.2 to 6.o prior to use in this "J invention. Should the purified synthesis gas be excessively rich in carbon oxides, it may be brought within the preferred range by the well known water-gas shift reaction.
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~0~;2Z85 On the other hand, should the synthesis gas be excessively rich in hydro~en, it may be adJusted into the preferred range by the addition of carbon dioxlde or carbon monoxide. Purified synthesis gas adjusted to contain a volume ratlo of hydrogen-to-carbon oxides of from 0.2 to 6.0 will be referred to as "ad~usted" synthesis gas.
Art-recognized equivalents of synthesis gas may also be employed.
- Mixtures of carbon monoxide and steam, for example, or of carbon dioxide and hydrogen, to provide ad~usted synthesis gas by in situ reaction, are contem~
plated. Furthermore, when the process of the invention is used to produce hydrocarbon mixtures rich in aromatic hydrocarbons~ as will be more fully . described, a hydrogen-donor such as methane, methanol, or higher alcohols may advantageously be charged with the feed.
Ihe component characterized by catalytic activity for the reduction of carbon monoxide may be selected from any of the art-recognized catalysts for producing hydrocarbons, oxygenated products, or mixtures thereof, from synthesis gas, and constltutes from 0.1 to 99, preferably from 1 to 8O percent by welght of the active components of the catalyst. Broadly, these components .. . .
include those recognized as methanol synthesis catalysts, Fischer-Tropsch . synthesls catalysts, and variants thereof. Commercial methanol synthesls : . .
catalysts comprisin~ metals or oxides of zinc together with chromia, or of zinc and copper together with chromia or alumina, or known modificatlons of these, are included. In fact, synthesis gas will undergo converslon to , form reduction products of carbon monoxide, such as alcohols and hydrocarbons, , at from about 300F to about 850F, under from about 1 to 1000 atmosphers ~3 25 pressure, over a fairly wide variety of catalysts. The prominent types of catalyst that induce conversion include the metals or oxides selected from the Groups consisting of IB, IIB, IIIB, IVB, VIB and VIII taken alone or in combination with one another. They particulariy include the metals or oxides . ~ , of zinc, iron, cobalt, nickel, ruthenium, thorium, rhodlum and osmium.
Fischer-Tropsch-type catalysts based on iron, cobalt, or nickel, and especially iron, are particularly suited for the production of oxygenated and hydrocarbon products that have at least one carbon-to-carbon bond in their structure. ~ith the exception of ruthenium, all practical, art-` recognized synthesis catalysts contain chemical and structural prc~oters.
lhese promoters include copper, chromia, alumina, the alkaline earths, `~ the rare earths, and aIkali. Alkali, e.g., the carbonates of Group IA of the periodic table, and especially of potassium, is of partlcular importance with iron catalysts, since lt grea~ly enhances the product distribution Supports such as kieselguhr someti~.es act beneficially.
It should be recognized that the carbon monoxide reducing component may be furnished as elemental metal or as corresponding metal compounds.
Frequently in the preparation and use of such catalytic substances there will be one or more partial or complete transformations from elemental metal to co~lpounds, or vice versa. By way of illustration, pure iron, roasted in an oxygen atmosphere in the presence of added aluminum and potassium nitrates provides a composition that contains 97% Fe304, 2.4% A1203, and o.6% K20 with trace amounts of sulfur and carbon. This composition after reduction with hydrogen at about 850F catalyzes the conversion of synthesis gas at a temperature in the range of about 360F to 430F, and at elevated pressures up to about 20 atmospheres, 65% of the carbon monoxide being reduced to a . ................................................ .
mixture consisting of about one-third by weight of hydrocarbons boiling in the range of 2C0F to about 680F, and about two-thirds of oxygenated compounds,mostly alcohols, in the same boiling range. M~nganese nodules may be used as catalyst.
The crystalline aluminosilicate component of the heterogeneous catalyst is characterized by a pore dirnension greater than about 5 Angstroms, i.e., it is capable of sorbing paraffins having a single methyl branch as well . . .

'~ ~

.
~: -as normal paraffins, and it has a silica-to-alumina ratlo of at least 12.
Zeolite A, for exanple~ with a sillca-to-alumina ratio of 2.0 ls not useful in this invention, and it has no pore dimenslon greater than about 5 Angstroms.
The crystalline aluminosilicates herein referred to, also known as zeolites, are characterized by a rigid crystalline framework structure composed of SiO4 and A104 tetrahedra cross-linked by the sharing of oxygen atoms, such a structure gives rlse to precisely defined pores. Exchangeable cations are present to balance the negative charge on the Alo4 tetrahedra.
The preferred zeolites useful in this invention are selected from a recently identified class of zeolites with unusual properties, by themselves being capable of catalyzing the transformation of aliphatic hydrocarbons to aromatic hydrocarbons in commercially desirable yields. Ihey are also - generally highly effective in alkylation, isomerization, disproportionation ; ~nd other reactions involving aromatic hydrocarbons. In many instances they ~J 15 have unusually low alumina contents, i.e. high silica to alumlna ratios, and they are very active even with sillca to alumina ratios exceeding 30. Further-more they retain their crystallinity for long periods in spite of the presence of steam even at such high temperatures as induce irreversible collapse of the cr~stal framework of other zeolites, e.g. those of the X and A type~
^ 20 Carbonaceous deposits, when formed, may be removed from them by burning at higher than usual temperatures to restore actlvity, although in many environ-ments they exhibit ver~ low coke forming capability, conducive to very long times on stream between burning regenerations.
The silica to alumina ratios referred to pertains, of course, only to the tetrahedrally coordinated silicon and aluminum. Although zeolites with a silica to alumina ratio of at least 12 are useful, it is preferred to use --zeolltes having ratios of a~ least 30. Such zeolites, after activation, acquire an intracrystalline sorption capacity for normal hexane which is greater than that for water and can be termed "hydrophobic": such zeolites . .

, are advantageously employed in the present inventlon.
The zeolites useful as catalysts in this invention freely sorb normal hexane and have a pore dimension greater than about 5 Angstroms. In addition, their structure must provide constrained access to some larger molecules. It is sometimes possible to Judge from a known crystal structure whether such constrained access exists. For example, lf the only pore windows in a crystal are formed by 8-membered rings of oxygen atoms, then entry of molecules of larger cross-section than no~mal hexane is substantially prevented and the zeolite is not of the desired type. Zeolites with windows of 10-membered rings are preferred, although excessive puckering or pore blockage may render these zeolites substantially ineffective. Zeolites with windows of twelve-menbered rings do not generally appear to offer sufficient constraint to produce the advantageous conversions desired in the instant invention, although structures can be conceived, due to pore blockage or other cause, that may be operative.
Rather than attempt to ~udge from crystal structure whether or not a zeollte possesses the necessary constrained access, a simple determination of the "constraint index" may be made by continuously passing a mixture of equal weight of normal hexane and 3-methylpentane over a small sample, approximately 1 gram or less, of zeolite at atmospheric pressure according to thefollowingprocedure. A sample of the zeolite, in the form of pellets or extrudate, is crushed to a particle size about that of coarse sand and mounted in a glass tube. Prior to testing, the zeolite is treated with a stream of air at 1000F for at least 15 minutes. The zeolite is then flushed with helium and the temperature ad~usted between 550F and 950F to give an overall conversion between 10% and 60%. ~he mixture of hydrocarbons is passed at 1 liquid hourly space velocity (i.e., 1 volume of liquid hydrocarbon per - volume of catalyst per hour) over the zeolite with a helium dilution to give a helium to total hydrocarbon mole ratio of 4:1. After 20 minutes on stream, .

a sample of the effluent is taken and analyzed, most conveniently by gas chrornatography, to determine the fraction remaining unchanged for each of the two hydrocarbons.
The "constraint index" ls calculated as follows:
Constraint Index = log 1~ (fr~action of n-hexane rem~lnln~) log 10 (fraction of 3-methylpentane remaining) e constraint index approximates the ratio of the cracking rate constants for the two hydrocarbons. Catalysts suitable for the present inveIltion are those which ernploy a zeolite having a constraint index from 1.0 to 12Ø Constraint Index (CI) values for some typical zeolites including some not within the scope of this inventlon are:
Zeolite C.I.
:, ` ZSM~5 8.3 ZSM~ll 8.7 ~MA Offretite 3.7 ZSM~12 2 Beta 0.6 ZSM-4 0.5 H-Zeolon 0.5 ` REY o.4 Amorphous Silica-alumina 0.6 ` Erionite 38 It must, of course, be borne in mind that the very nature of thls Index, and the technique by which it is determined, admit the possibillty that a given zeolite can be tested under somewhat different condltions and thereby have different constraint indices. Constraint Index seems to vary somewhat with severity of operation (conversion). ~herefore, it may be possible to so select test conditions to establish multiple constraint indexes for a particular zeolite which may be both inside and outslde the above defined ` 25 range of 1 to 12. This invention includes within its scope any zeolite which - manifests a constraint index in the range 1 to 12 at some combination of q - g _ ;

~ .

conditions within the scope of the determinatlon procedure set forth above, whether or not it manifests an index outside that range at other such combinations of conditions.
This class of zeolites is particularly well exemplified by zeolites ZSM-5, ZSM-ll, ZSM-12, ZSM-35 and ZSM-38. ZSM-5 is descrlbed in U.S. Specification 3,702,886; ZSM-ll in U.S. Specification 3,709,979;
ZSM-12 in U.S. Specification 3,832,449 and ZSM-35 and 38 in U.S.
specification 4,016,245 and 4,046,859 and French publlshed appiication 74-12078.
The specific zeolites described, when prepared in the presence of organic cations, are substantially catalytically inactive, possibly because the intracrystalline free space is occupied by organic cations from the forming solution. ~hey may be activated by heating in an inert atmosphere at 1000F for one hour, for example, followed by base exchange with ammonium salts followed by calcination at 1000F in ~ir for from 15 minutes to 24 hours. The presence of organic cations in the forming solution may not be absolutely essential to the formation of this special type zeolite, but does appear to favour lt.
Natural zeolites n~ay sometimes be converted to this type of zeolite by various activation procedures and other treatments such as base exchange, steaming, alumina extraction and calcination, alone or in combinations. Natural minerals which may be so treated include ferrierite, brewsterite~ stilbite, dachiardlte, epistilbite, heulandite and chinoptilolite.
me zeolites may be used in the hydrogen form, metal-exchanged .':t form or ammonium forn. The metal cations that may be present include any of the cations of the metals of Groups I through VIII of the periodic table, although Group IA metal cations should not be present in large quantity.
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~ e ~r.~st preferre~ zeolltes are those which ha~e a cr,ystal framework density, in the dry ~ydro~en form, of nct suhstantially below about 1.6 gr2ms per cubic centimeter. me dry density I'or known structures ~y be calculated from the number o~ sllicon plus alu Illun atons per IOOO cublc An~str~ns, as .

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given, e.g., on page 19 of the article on Zeollte Structure by W. M. Meler in "Proceedings of the Conference on Molecular Sleves, London, Aprll, 1967", publlshed by the Society of Chemical Industry, London, 1968. When the crystal structure is unknown, the crystal framework density may be determlned by -classical pyknometer techniques. For example, it ~ay be determined by inmersing the dry hydrogen form of the zeollte in an organic solvent which is not sorbed by the crystal. It is possible that the unusual sustained activity and stability of this class of zeolites ls associated with lts hlgh crystal anlonic frame~ork denslty of not less than about 1.6 grams per cublc centl-meter. This high denslty of course must be associated with a relatively small amount of free space within the crystal, which might be expected to result ; in more stable structures. mls free space, however, seems to be important as the locus of catalytic activity.
- Crystal framework densities of some typical zeolites including some which are not within the ppurview of this inventlon are:
. Void Framework Zeollte Volume Density Ferrierite 0.28 cc/cc 1.76 g/cc Mordenite .28 1.7 ZSM~5,-11 .29 1.79 Dachiardite .32 1.72 ~-- L .32 1.61 Clinoptllolite .34 1.71 Laumontite .34 1.77 -~ ZSM~4 (amega) .38 1.65 i Heulandite .39 1.69 P .41 1.51 O.~fretite .40 1.55 Levynite .40 1.54 Erionite .35 1.51 Gmelinite .44 1.46 2 Chabazite .47 1.45 ; 5 A .5 1.3 Y .48 1.27 .~
., , The hetero~eneous catalysts of thls invention may be prepared in various ways. The two components may be separately prepared in the forn of catalyst particles such as pellets or extrudates, for example, and simply mixed in the required proportions. The particle size of the indlvidual component particles may be quite small, for example, from about 20 to about 150 microns, when intended for use in fluid bed operation; or they may be as large as up to about V2 inch for fixed bed operation. The two components may be mixed as powders and formed into pellets or extrudate, each pellet containing both components in substantially the required proportions. Binders such as clays may be added to the mixture. Alternatively, the component that has catalytic activity for the reduction of carbon monoxide may be associated with the crystalline aluminosilicate component by means such as impregnation of the zeolite with a salt solution of the desired metal, followed by drying and calcination. Base exchange of the crystalline aluminosilicate component also may be used in some selected cases to effect the introduction of part or all of the carbon monoxide reduction component. Other means for formlng the intimate mixture include precipitation of the carbon monoxide redubtion component in the presence of the crystalline alum~nosilicate; electroless deposition of metal on the zeol.ite; and deposition of metal from the vapor phase. Various combinationsof the above preparative methods will be obvious to those skilled in the art ~; of catalyst preparation, as will the necessity to avoid techniques likelg to reduce the crystallinity of the crystalline aluminosilic~te.
It will be clearfrom the foregoing that the mixtures used in the process of this invention may have varying degrees of intimacy. At one extreme, when using 1/2 inch pellets of the carbon monoxide reducing component mixed with 1/2 inch pellets of the crystalline aluminosilicate, substantially ` all locations within at least one of the components will be within not more than about 1/4 inch of some of the other component, regardless of the proportions in which the two components are used. With different sized pellets, e.g., V2 .., - .- ~ - -. .
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- inch and 1/4 inch, again substantially all locatlons within at least one of the components wlll be within not more than about 1/4 inch of the other component. These examples lllustrate the lower end of the degree of intimacy required for the practice of this invention. At the other extreme, one may ball mill together crystalline aluminoslllcate particles of about 0.1 micron particle slze with colloidal iron oxide of similar partlcle slze followed by ` pelletization. For this case, substantially all the locatlons withln at least one of the components will be within not more than about 0.05 micron of some of the other component. This exempllfles about the hlghest degree of intimacy that is practlcal.
In the process of this invention, synthesis gas ls contacted with the heterogeneous catalyst at a temperature of from about 400F to 1000F, preferably from 500F to 850F, at a pressure from 1 to 1000 atmospheres~
preferably from 3 to 200 atmospheres, and at a volume hourly space velocity from about 500 to 50,000 volumes of gas (STP) per volu~e of oatalyst; or equivalent contact time if a fluldized bed ls used. me product stream con-ta~nlng hydrocarbons, unreacted gases and steam may be co~led and the hydro-carbons recovered by any of the techniques khown in the art. The recovered hydrocarbons may be further separated by dlstillatlon or other means bo recover one or more products such as high ootane gasoline, propane flel, benzene, toluene, xYlenes, or other aromatlc hydrocarbons.
Some embodiments of the inventlon are set forth by way ~f 111U
tratlon in the following Examples.

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Example 1 8551 Thoria was prepared according to the methad of Pichler and Ziesecke, as described in "The Isosynthesis," U. 5. Bureau of Minès Bulletin, 488 (1950), which involved essentially the pre-cipitation of ThtNO3)4 solutions with Na2CO3 solutions followed by filtration, washing and drying at 100C.
~A composite catalyst was prepared b~ ball-millihg equal weights of NH4ZSM-5 and dried thoria gel, pelleting and calcining ; at 1000F for 10 hours. Three experiments were done, eaah one at 800F, 1215 psia, and with a mixture of hydrogen and carbon monoxide having a H2/CO ratio of 1Ø The first and second runs involved thethorium oxide and HZSM-5, each used separately, while the third run employed a heterogeneous catalyst containing both thorium oxide and HZSM-5.
The results are summarized in Table 1.
.
:
: TABL~ 1 (A) (B) (C) ThO2 plus Catalyst l'hO2 HZSM-5 HZSM-5 Alone Alone Contact Time - seconds 15 15 15 (at reaction conditions) . ~.
Conversion, wt. %
CO S.3 ~ 1 22.4 H2 2.6 ~ 1 15.2 Wt. % Hydrocarbons in total reaction effluent 0-6 0.2 5.5 '~
HYdrocarbon Distribution (wt. %) Methane 41.0 39.6 17.3 C2-C4 hydrocarbons 5~.6 60.4 73.8 : C5+ l00.0 l00.0 108.0 Aromatics in C5+, wt. % Trace Trace 41.6 . , , .._ ... . ..., .....
.. . . . .
- , ' ~ ' - ' 106ZA~85 Example 2 8551 A ZnO supported on A12O3 was obtalned f~om a commercial source and was used as the carbon monoxide reducing component.
It contained 24% by weight of ZnO. HZSM-5 was used as the acidic crystalline aluminosilicate component.
The heterogeneous composite catalyst ~as prepared by ball-milling together four parts of the HZSM-5 to one parbi of the ZnO/A12O3 catalyst, followed by pelletizing. Two runs were car-ried out, both at 600F, 750 psia, and with a mixture of hydragen and carbon monoxide having a H2/CO ratio of 4, The first run used the ZnO/A12O3 catalyst alone, while the second run employed a composite catalyst containing both the ZnO/A1203 and HZ~M-5 catalysts.
The results are shown in Table 2.

(D) ~E) 2~h ZnO/A12O3 plus .. CatalYst zno/A12o3 80% HZSM-5 Alone Compos~te Contact Time - seconds 25 25 ~at reaction conditions) Conversion, wt. % ~`
- CO 32.0 6.7 H2 5.4 3.4 Wt. % hydrocarbons in ; total reaction effluent 0.2 1.0 HYdrocarbon Distribution (wt. %) Methane 100.0 11.4 C2-C4 hydrocarbons - 42.9 C5 - j 45.7 ,, 100. 0 100. 0 ~ Aromatics in C5+ (wt. %) None 71.8 ''' ,-' .. ' ' '~.

-15- `

1~62Z85 Example 3 8551 A methanol synthe~is catalyst was prepared containing the following percentages by weight; copper - 54.SS, ~inc -27.27, chromium - 9.09, and lanthanum - 9.09 o~ an oxygen-free basis. A composite catalyst was then prepared from equal parts of this component and HZSM-5, using 5~D graphite as a binder~
Two runs were made, each at ~00F, 750 psia, uslng a~ a f~ed - a mixture of hydrogen and carban monoxide with a H2/C0 ratio of 2 and are summarized in Table 3.

Table 3 (F) (G) ~ethanol ~ype plus Catalyst Methanol Type H~S~-~
Alone Composlte Space Velocity on Methanol Catalyst Component 5825 6764 (cc of synthesis gas/g. of methanol catalYst/hour) C0 Conversion wt. % 24 34 Wt. % in Water-Free Product ; Methane 0.7 1~1 C2-C4 ~ydrocarbons1.0 5.7 C5+ Hydrocarbons -2 7 8.6 As shown, the contact times ~recip~ocal of 6pace ~eldcity) relative to the methanol catalyst component are ~ery s~milar ; in the two runs; being slightly lower with the domposite catalyst.
The composite catalyst shows a much greater production of hydrocarbons, particularly hydrocarbons higher ln carbon number than methane, than the carbon mohoxide reducing component by it~elf.
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¦ Example 4 1 ~ 2Z 8 5 The carbon monoxide reducin~ component was a commerciaI iron oxide type ammonia synthesis catalyst containing small a7inounts of K, Ca and Al promoters. The zeolite component contained 65%
8551 HZSM-5 and 35% alumina binder. The heterogeneous compo~ite cata-lyst contained 75% of the iron component and 25% o~ th~ ~eolite component, and was made by ball-milling the c~mponents ~nd then pelleting the resultant powder.
Three runs were made at 700F, 265 p~ia and with a mixtu~e of hydrogen and carbon monoxide having a Hz~CO ratio of 1.~.
Results are summarized in Table 4.
~ABLE 4 (H) (J) I (K) CatalYst ~e Fe/HZSM-5 Fe+H~SM-5 Compone-lt ~omponents not omposite Alone mixe~. Compo~ catalyst, nents in sepa- single reac-~ate reaction tion zohe zones in series Contact time - seconds 15 3b 15 (at reaction conditions) ~onversion wt. %
CO 93.5 96.9 98.4 H2 67.8 76.9 72.3 Wt. % Hydrocarbons in total reaction effluent 22.6 25.6 25.5 Hydrocarbon Distribution (wt. %) Methane 44.6 50.1 5~.6 C2-C4 hydrocarbons 50.1 41.1 41~4 C5+ S.3 8.8 6.0 Aromatics in C5+, wt. % 1.9 2.3 15.0 Experiment H illustrates the selbctivit~ of the iron ~om-ponent in the absence of HZSM-5; th~ CS~ hy~rocarbons containan~y 1.9% aromatics. In experiment (j), a rea~tion kone ~ontaihing HZSM-5 was placed after the reaction zone containing the iron catalyst. It can be seen that the aromatics selectivi~y t7as not significantly changed. In exper~nent (k), howeve~, tha intin~t~
mixture of HZSM-5 with the iron compone~t ga~e abo~t a seven-f01d increase in aromatics selectivity. - -. , -1?-.
, .

Example 5 The catalyst in this example wa~ prepared b~ Lmpregnation of NH4ZSM-5 containing 35% alumina binder with a bo~ution of Fe(NO3)3, drying the catalyst and calcining at 1000~ for 10 8551 hours. The PinishQd catalyst contained 3% iron. Synthasi~ gas (H2/CO = 1) was reacted over this catalyst at 70~F, 515 ps~a tnd 30 seconds contact time, giving the Pollowing conve~sions and products.

TA~LE_$
. CatalYst ~HZSM-5 Contact Time - seconds 30 . (at reaction condi,tions~

: . Convers _n, wt. ~O
: CO i9.7 . H2 12.0 . ~ , .
Wt. % Hydrocarbons in total reaction effluent 8.1 . Hvdrocarbon Distripution (wt- ~/O) Methane 33.4 .
C2-C4 hydrocarbon8 ~. 47.5 . C5+ . . 19.1 A = ~tic~ ~ 24.6 , ' , ' '' ' .
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~06Z~85 ExamPle 6 t The catalyst in this example was an int~ate mlxture o~
57.4% ilmenite sand (FeO-TiO~), 21.3% HZSM-5 and 21.3% alumina 8551 binder. Synthesis gas ~H2/CO - 1) was reacted over ~aid catalyst ,, at 700F, ~d 265 psia and 10 ~conds contact t~e, giv$ng the following conversion and products.

Catalyst ~lmen~te ~ HZSM-5 . ' .
Contact Time - seconds 10 ~at reaction conditions) Co~v r ' CO 62.3 H2 48.3 Wt. % Hydrocarbons in to,tal reaction e~fluent ~ ~1.9 drocarbon Distribution_ (wt. %) Methane 2g.2 C2-C4 hyd~ocarbons 59.1 j:
C5 11.7 -Aromatics in C5+, wt. % 29.g .' . ' . ,.' ' ' .
.~, _____ ...... ..

. ~ . . - . , . . -Example 7 . _ The catalyst in thi~ example was an intimatè mixture of 41.2~ magnetite (Fe304), 29~4% HZSM~5 and 2~.4% alumina binder.
Synthesis gas (H2/C0 = 1) was reacted over said catalyst at 700~F, 8551 265 psia and 10 seconds contact time, giving the following can-versions and products.

Catalvst Magnetite ~ HZSM-5 Contact Time - seconds 10 (at reaction conditions) . ConversionL wt. % .
CO 41.8 .; H2 37.6 - .
. .
.. Wt. % Hydrocarbons ln ~: total reaction effluent ~6.6 .' . . .
Hydrocarbon Di,s,tribution_!wt. %) , Methane - 31.0 .
:~ C2-C4 hydrocarbons . 55.0 ~ C5+ 14.0 .
. Aromatic~ in C5+, wt. ~ 19.9 ~ .
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Example 8 ' The catalyst in this example wa~ an int~m~te mixture of 41.2% iron carbide, 29.4% HZSM-5 and 29.4% alumina binder.
8551 Synthesis gas (H2/C0 2 1) was reacted over said catal~st at 700~, 265 psia and 10 seco~ds contact time, giving the following con-versions and products.
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:' . Catalv,st Iron carbide + HZSM-5 . ' . Contact Time - seconds . 10 ~ (at, reaction conditions) , , :. Conversion, wt. %.
CO 11.7 R2 11.1 Wt. % Hydrocarbons in .
total reac.tion.efluent 4.5 :~ _ drocarbon Distribution (wt.l~, , , ~ Methane 40.8 ., . . C2-C4 hydro~a~bons SO. 1 ' ,' ' C5+ . g.l 1 Aromatic~ in C5~; wt.,% 6.2 : : ~ :
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Example g The catalyst of thiæ example was prepared by lmpreghating an extrudate comprising ZSM-5 crystalline zeolite containing about 35% ~lumlna as binder-with a solutlon of iron ~Fe(N03)3] followed by dry~ng and ~educing with hydrogen at a temperature of about 950F. Three di~erent levels of iron lmpregnation ~ere prepared as identi~led ~n Table 10. Synthesle ; gas (H2/C0 5 2) ~a~ passed in contact with th~ catalyst a~ a temperature of 600F~ and a pressur~ of 200 psig. The results obtained are ~s follows:
Table ~
E~FECT OF FE ~ONCENTXATION
~MPRE~NATED" ~ 5 EXTRUDATE
600F BBD SETTING, 200 PSIG, 2 H~/CO, 3300 GHSV
~ : .
Iron, Wt.% 8 6 14.~ 21.7 CO Conversion, Wt.% 43 65 83 % Wt. C Converted to:

Hydro¢arbon 7 65 64 ; Hydrocarbon Composit~on, Wt.%.
Cl 38 ; 42 38 . C2 i~ i6 14 C . 9 8 7 C5 4 ~ 6 C6$ 23 ?l 27 . C6~ Aromatlc~, Wt.% 46 42 34 .

-?Z-~062~85 Ex~le ,10 . The catalysts used in this example comprised a mixture of ZSM-5 alumina e~trudate (65/35 ratio) with a copper methanol synthesis catalyst.
In Runs 912-1 and 2, the volume ratio of ZSM-5/Cu synthesis catalyst was 2.9i2 and in Runs 913-3 to 5, the volume ratlo of ZSM~5/C~ synthesis catalyst was 4~1. Ihe ~,M~5 alumlna extrudate was àlso mixed with an iron ammonia synthesis catalyst in a 4/1 ratio and used as the catalyst in Runs 903-1, 2 and 6. The operatin~ conditions employed and results obtained in the re:pectlve F~ns s~e ldent~rled ln Table 10 below.

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~062Z85 ~Ple ~1 -A thoria-Z~M-5 cRtaly~t ~no alu~iha) pr~ e~ a~
identifled in Example 1 above was ~ed in t~o ~eparat~ ~UnB
~or comparison wlth a similar cataly~t containing ~he alumina binde~ as ~hown belo~. In these exampl~s sy~thes~ gaà .
. (H ~C0 - 1) was pas~d in co~tact wlth tn~ cataly~t at - temperature or 800F. and a press~re of 1200 paigl The : re~ult6 obtained ~re pre~ented ~n Table lI belbwl . . .

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Tablell SYNGAS CONVERSION OVER ThO2/HZSM-5 800F. 1200 PSIG, H2/CO ~ 1 ThO~/H~SM-5 m ~ ~ HZSM-5 (No A1~03) ~ r ~&~ ~ hr. 205 205 375 - Time on Stream, hr. 26 267 94 . Conversio~ wt.%
CO 3~,g 58.1 10.1 H 21.3 J~5.6 1~9 Total Product, wt.~.' Hydrocarbon~ ~~ .g8 3.. 66 Oxygenate 8 - -H~O ~5 ~g 29 ~
Co2 60.36 39.~3 ~4.90 2 ~ 9 . 3~ 6.~
. . .
- Hydrocarbons, wt.%
I - Methane 13.6 11.3 , 9~7 :~ Ethane 36.7 28.0 . lg.5 Ethylene a, z o . 1 ~
Propane 33~0 2l~,8 ~J~.l Propylene 0.2 0.2 ~
! i-Butane 5,4 4~ 1.7 n-Eutane 3,~ ~.7 ~,g Buteneæ ~ ~ ~
i-Pentan~ O.g Q.6 n-Pentane 0.2 tr. ~r Penteneæ
C6+ 004 _ tr Aromatlc 8 4. r 27~7 53.3 Tatal C + 7.1 '28,6 53,9 Aromatio~ in C5+ 66, e 96, g g~ ~ g ' --~ -26- .
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106;2Z85 Ex~mple12 Ruthenium dioxlde has been used as a Fi~cher-~ropsch catalyst to convert synthesis gas into par~ffin wax ~nder high pressure and low temperature (248-428F). Howev~r, at higher temperature (572F.), o~lg methane is formed. Rutnenlum~on- -alumlnum has alæo been used ~or synthesis conversioh to produce gaseous~ liquid and solid hydrocarbons~ however, agaih, m~tnahe becomes the maJor product at temperature~ h~ghe~ than 482F.
No aromatics are pro~uced using these catalgsts, Now, it~has been found that ruthenium, in combination with H~æM~ 5, produces ar~matica-containing gasoline in high yleld from synthesis ~as over a wide temperature range.
. ~ , ExamPle A
. A 5% ruthenium ~n ZSM-5 catalyst was prepared by vac~um `~ impregnating 10 g. of NH~-ZSM-5 with a 18 ml. à~ueou~ solution containing 1.25 g. RUC13-3H20~ After dryin~ in ~acuum ~he catalyst was air calcined ln an oven at 1000F. for two hours.
This resulted ln a ¢on~ersion of the ~mo~ium for~ of ZSM-~ td . . .
the hydrogen form.
Example B
A 1% Ru/ZSM~5 catalyst ~B prepa~ed using the ~rocedure of Example A, except ~h~t Z0 ~ o~ NH4-~SM-5 with a 36 mi. aqueous solution containing 0.5 g. of RuC13-3H20 wa~ u~ed.
,' .Ex~mPle C, .
The can~ersion of synthesi~ gas (H2/C0) wa~ carried out in a fixed-bed ~ontinuoùs fio~ reactor~ The stainless ~eel : reactor was char~ed wlth 5.5 g. of the 5~ ~ /ZSM-5 cathiyst : -. . . .
s prepared in Example A, the catalyst was prereduced Nith ~lowlng .
~ hydrogen at 750F. and a pressure a~ 750 psig ~or three hours.

. . .
~ -27-: :, The conversion of 6ynthesis gas (H2iCo) wa~ carried out at 750 pBig . 580F~ WHSV - 0.32 and H2/C0 = 2h . The results and the detailed hydrocarbon distributlon are g~ven ln Table 13 below. Hlgh conversion with good selectivity ta i llquid (C5+) produ~ts was obtained. The llquid product contalned 25% aromatlcs and h~d octane numbers ~+0 - 77 and R~3 = 92.
Exam~le_D
Syngas conversion was carried out under essentiallg the same condltions as ln Example C except that 5.5 g. of 1% Ru/ZSM-5 prepared in Example B was used. The results are llsted in Table 13 below. Hlgh conversion to hydrocarbans rich in C2+ and containlng 13.8% aromatics was obtained.

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Tcble 12 Synthesls Ga~ Con~er~lon over Ruthehlum/HZSM-5 Catalyst at 750 psig. 580F.WHSV=0.32 and H ~CQ-2/1. -Example C Example D
Catalyst 5%Ru/HZSM-5 1%~u/HZSM-5 Method of Catalyst ;Preparation Impregnation I~prégnation Conversion, wt.%
C0 82.9179.31 H2 88.3284.84 Total Reactor Effluent, wt.%
-l Hydrocarbons 37.~431.83 H2 1.46 1.92 C0 14.951~.07 2 ~2.312.65 ; H20 43.7445~53 Hydrocarbon Composition, wt.~
~ 1 31.11 20.42 -i C2 6.61 4.02 C3 6.82 7.79 C4 9.22 16.78 C5+ 46.24 50.99 AromQtics in C5+ 24.84 Z7.04 Aromatic~ in C6+ 29.57 34.78 Aromatics in Total H.C. 11.51 13.79 Hydrocarbon Selectivity* 98-5~ 97.60 Octane No. of C ~77 (R+0) 92 (R~3) ., .
~' *(Total carbon con~erted ~ Total carbon in C02)/Total carbon converted.

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Claims (12)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A process for producing hydrocarbons which comprises contacting synthesis gas at a temperature within the range 450° to 1000°F and elevated pressure with a catalyst comprising a metal or metal compound having catalytic activity for the reduction of carbon monoxide and a crystalline aluminosilicate having a pore diameter greater than 5 Angstroms, a silica to alumina ratio of at least 12, and a constraint index within the range of 1 to 12.

2. A process according to claim 1 wherein said metal or metal compound comprises from one to eighty weight percent of the catalyst.

3. A process according to claim 1 wherein said metal and said crystalline aluminosilicate are in the same particle.

4. A process according to claim 1, 2 or 3 wherein said metal is a Group VIII metal.

5. A process according to claim 1, 2 or 3 wherein said metal is thorium.

6. A process according to claim 1, 2 or 3 wherein said metal is copper or zinc.

7. A process according to claim 1 wherein said crystalline aluminosilicate is zeolite ZSM-5, ZSM-11, ZSM-12, ZSM-35 or ZSM-38.

8. A process according to claim 7 wherein said zeolite is at least partly in the hydrogen form.

9. A process according to claim 1, 2 or 3 wherein the volume ratio of hydrogen to carbon oxides in the synthesis gas is within the range 0.2 to 6Ø

10. A process according to claim 1, 2 or 3 wherein the ratio of metal component to crystalline aluminosilicate is selected to promote the production of gasoline boiling range hydrocarbon.

11. A process according to claim 1, 2 or 3 wherein said metal or metal compound is present in the form of a Fischer-Tropsch catalyst.

12. A process according to claim 1, 2 or 3 wherein said metal or metal compound is present in the form of a methanol synthesis catalyst.