CA1080689A - Hydrocarbon conversion process and catalyst therefor - Google Patents
Hydrocarbon conversion process and catalyst thereforInfo
- Publication number
- CA1080689A CA1080689A CA103,565A CA103565A CA1080689A CA 1080689 A CA1080689 A CA 1080689A CA 103565 A CA103565 A CA 103565A CA 1080689 A CA1080689 A CA 1080689A
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- rhenium
- hydrocarbon
- catalyst
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Abstract
ABSTRACT OF THE DISCLOSURE
A catalytic compoe te comprising a platinum group component, a rhenium component, and a tin component with a porous carrier material is disclosed. The principal utility of this composite is in the conversion of hydrocarbons, particularly in the reforming of a gasoline fraction. A
specific example of the disclosed catalytic composite is a combination of a platinum component, a rhenium component, a tin component, and a halogen component with an alumina carrier material.
A catalytic compoe te comprising a platinum group component, a rhenium component, and a tin component with a porous carrier material is disclosed. The principal utility of this composite is in the conversion of hydrocarbons, particularly in the reforming of a gasoline fraction. A
specific example of the disclosed catalytic composite is a combination of a platinum component, a rhenium component, a tin component, and a halogen component with an alumina carrier material.
Description
1C~8~)689 The subjest of the present invention is a novel catalytlc composite whlch has exceptional activity and reslstance to deactivation when employed ln a hydrocarbon conversion process that requires a catalyst having both a hydrogenation-dehydrogenatlon function and a cracking func-tion. More precisely~ the present invention lnvolves a novel dual-function catalytic composite which9 quite surprisingly, enables substantial improvements in hydrocarbon conversion processes that have traditionally used a dual-function catalyst.
In another aspect, the present invention comprehends the improved processes that are provlded by the use of a caialytic composite comprising a platinum group component, a rhenium component, and a tin component with a porous carrier material; specificallyO an improved reforming process which ~15 utillzes the subject catalyst to improve activity, selectivity, and stability characteristics.
Composi~es having a hydrogenation-dehydrogenation function and a cracking function are widely used today as catalysts in many industries, such as the petroleum and petro-chemical industryg to accelerate a wide spectrum of hydrocarbon c-nversion reactions. Generally, the cracking function is thought to be associated with an acid-acting material of the ., .
108~)~85~
porous, adsorptive, refractory oxide type whlch is utilized as the support or carrier for a heavy metal component~ such as the metals or compounds of metals of Group V through VIII
of the Perlodic Table, to which lS generally attributed the hydrogenation-dehydrogenatlon function.
These catalytic composites are used to accelerate a wide variety of hydrocarbon conversion reactions such as ~hydrocracking~ isomerization~ dehydrogenation~ hydrogenation, desulfurizationt cyclization, aikylation; polymerlzation, iO cracking and hydroisomerization. In many cases, the commer-cial applications of these catalysts are in processes where more than one of these reactions is proceeding simultaneously.
An example of this type of process is reforming wherein a hydrocarbon feed stream containing paraffins and naphthenes is subjected to condltions which promote dehydrogenation of naphthenes to aromatics, dehydrocyclization of paraffins to aromatics, lsomerization of paraffins and naphthenes~ hydro-cracking of naphthenes and paraffins and the like reactions, to produce an octane-rich or aromatic-rich product stream.
Another example is a hydrocracking process wherein catalysts of this type are utilized to effect selective hydrogenation and cracking of high-molecular--weight, unsaturated materiais, selective hydrocracking of high molecular weight materials, and other like reactions, to produce a generally lower boiling, more valuable output stream~ Yet another example is an isomerization process wherein a hydrocarbon fraction which is -- - .
1080~i89 relatitely rich in straight-chain paraffin components is con-tacted with a dual-function catalyst to produce an output stream rich in isoparaffin compounds.
Regardless of the reaction involved or the particular process involved, it is of critical importance that the dual-functlon catalyst exhibit not only the capabil~ty to initially perform its specified functions, but also that it has the capability to perform them satisfactorily for prolonged periods of time. The analytical terms used in the art to measure how well a particular catalyst performs its intended functions in a particular hydrocarbon reaction environment are activity, selectivityf and stability. And for purposes of discussion here, these terms are conveniently defined for a given charge stock as follows: (1) activity is a measure of the catalyst's L5 ability to convert hydrocarbon reactants into products at a specified severity level where severity level means the condi-tions used -- that is, the temperature, pressure, contact time, and presence of diluents such as hydrogen, (2) selectivity refers to the amount of desired product or products obtained 'O relative to the amount of reactants converted; (3) stability refers to the rate of change with time of the activity and selectivity parameters -- the smaller rate implying the more stable catalyst. In a reforming process, for example, activity commonly refers to the amount of conversion of a given charge '5 stock at a specified severity level and is-typically measured by octane number of the C5+ product stream; selectivity refers 10806~
to the amount o~ C5+ yield that lS obtalned at the particular severity level and stablllty refers to the rate of change with time of activity~ as measured by octane number of C5+
product, and of selectlvlty~ as measured by C5+ yield.
Generally a continuous reforming process is run to produce a constant octane C5+ product with severlty level being cor.tinuously adjusted to attain thls result. Furthermore, the severity level is for this process usually varied by ad-~ sting the converslon temperature in the reaction zone so that in point of fact, the rate of change of activity finds response in the rate of change of conversion temperatures and char.ges in thls last parameter are customarily taken as ir.dicative of activlty stabilityc As is well known to those skilled in the art, the .5 prlncipal cause of observed deactivation or instabllity of a dual-function catalyst when used in a hydrocarbon conversion reactlon is that coke forms on the surface of the catalyst.
More specifically, in these hydrocarbon conversion processes, the conditions utilized ~ypically result in the formation of heavy, high molecular weight, black, solid or semi-solid, - carbonaceous material which coats the surface of the catalyst and reduces its activity by shieldlng its active sites from the reactants. In other words~ the performance of this dual-~ function catalyst is sensitive to the presence of carbonaceous --~25 deposits on the surface of the catalyst. Accordlngly, the major problem facing workers in this area of the art is the development of more active and selective catalytic composites that are not as sensitive to the presence of these carbonaceous materials and/or have the capability to suppress the rate of the formation of these carbonaceous materials on the catalyst.
Viewed in terms of performance parameters, the problem is to develop a dual-function catalyst having superior activity, selectivity, and stability. In particular, for a reforming process the problem is typically expressed in terms of shifting and stabilizing the C5+ yield-octane relationship -- C5+ yield being representative of selectivity and octane being propor-tional to activity.
The present invention provides a dual-function catalytic composite which possesses improved activity, selectivity, and stability when employed for the conversion of hydrocarbons in processes for isomerization, hydroisomeri-zation, dehydrogenation, desulfurization, denitrogenization, hydrogenation, alkylation, dealkylation, hydrodealkylation, transalkylation, cyclization, dehydrocyclization, cracking, hydrocracking, reforming, and the like. In particular, a composite comprising a platinum group component, a rhenium component, and a tin component with a porous refractory carrier material enables the performance of hydrocarbon conversion processes utilizing dual-function catalysts to be substantially improved. Moreover, a catalytic composite comprising catalytically effective amounts of a platinum :108V~
component, a tin component a rhenium component, and a halogen component with an alumina carrier material can be utilized to substantially improve the performance of a reforming process which operates on a gasoline-boiling-range fraction to produce a high-octane reformate. In the case of a reforming process, the principal advantage associated with the use of the novel catalyst of the present invention involves the capability to operate in a stable manner in a high severity operation fo~ example, a low pressure reforming process designed to produce a Cs+ reformate having an octane of about 100 F-l clear.
As indicated, the present invention involves the discovery that the addition of a tin component and a rhenium component to a dual-function hydrocarbon conversion catalyst containing a platinum group component enables the performance characteristics of the catalyst to be sharply and materially improved O
It is,accordingly, one object of the present ~ inventlon to provide a hydrocarbon conversion process utilizing -~ a novel catalyst having superior performance characteristics.
~20 A second object is to provide a catalyst having dual-function hydrocarbon conversion performance characteristics that are relatively insensitive to the deposition of hydrocarbonaceous material thereon. A third object is to provide preferred methods of preparation of this catalytic composite which insures the achievement and maintenance of its properties.
Another object is to provide an improved reforming catalyst lO~Vtil~
having superior activity, selectivity, and stability. Yet another object is to provide a dual-function hydrocarbon conversion catalyst which utilizes a combination of a rela-tlvely inexpensive component, tin, and a relatively expensive component, rhenium~ to promote a platinum metal component.
Accordingly, the present invention provides a process for the conversion of a hydrocarbon, which comprises subjecting said hydrocarbon to contact at hydrocarbon con-`10 version conditions with a catalytic composite comprising a platinum group component, a rhenium component, and a tin component with a porous carrier material. The porous carrier material is a porous, refractory material such as a refractory inorganic oxide, and the tin component, the rhenium component, and the platinum group component are usually utilized in relatively small amounts which are effective to promote the desired hydrocarbon conversion reaction.
The invention further provides a catalytic com-posite comprising a platinum component, a rhenium component, and a tin component, with an alumina carrier material.
These components are preferably present in the composite in the following amounts, on an elemental basis; from about 0.01 to about 1 wt % platinum, from about 0.01 to about 1 wt YO rhenium, and from about 0.01 to about 5 wt % tin.
The composite may also contain a-halogen component in amount up to 10 wt %, but preferably in an amount within ~o~vtj~
the range from about 0.1 to about 1.5 wt % (elemental basis).
According to a further feature of the invention, the composite is reduced with hydrogen under substantially water-free conditions prior to use thereof in the conversion of hydrocarbons. The pre-reduced catalytic composite may be combined with a sulfur component in an amount which incor-porates therein from about 0.05 to about 0.5 wt % sulfur, calculated on an elemental basis.
A preferred embodiment of the invention provides a process for reforming a gasoline fraction which comprises contacting the gasoline fraction and hydrogen with the catalytic composite described above at reforming conditions selected to produce a high-octane reformate.
As indicated above, the catalyst of the present invention comprises a porous carrier material or support having combined therewith catalytically effective amounts of a platinum group component, a rhenium component, a tin component, and in the preferred case a halogen component. Considering first the porous carrier material utilized in the present invention, it is preferred that the material be a porous, adsorptive, high-surface-area support having a surface area of about 25 to about 500 m2/gm. The - porous carrier material should be relatively refractory to - the conditions utilized in the hydrocarbon conversion process, - 25 and it is intended to include within the scope of the present invention carrier materials which have traditionally been utilized in dual-functlon hydrocarbon conversion catalysts such as: (1) activated carbon, coke, or charcoal, (2) silica or silica gel, silicon carbide. clays, and silicates including those synthetically prepared and naturally occurring. which may or may not be acid treatedj for example, Attapulgus clay, ^hlna clayA diatomaceous earthf fuller~s earth, kaol1n, and kieselguhr; (3) ceramlcs, porcelain. crushed firebrick, bauxlte;
(4) refractory inorganic oxldes sucn as alumina, titanium diox'.de, zirconium dioxide, chromium oxide, zinc oxlde, magnesiaC thoria~ boria, silica-alumina, slllca-magnesia, chromia-alumina~ alumina-boria~ and sllica-zirconia; (5) crystalline aluminosillcates such as naturally occurring or synthetlcally prepared mordenite and/or faujasite, either in the hydrogen form or in a form which has been treated with mu.ltivalent cations; and, (6) combinatlons of these groups. The preferred porous carrier materials for use in the present invention are refractory inorganic oxides, with best results obtained with an alumina carrier material~
Suitable alumina materials are the crystalline aluminas known as the gamma-, eta-~ and theta-aluminas with gamma-or eta-alumina giving best results. In addition. in some embodiment~ the alumina carrier material may contain minor proportions of other well known refractory inorganic oxides such as silica, zirconia, and magnesia, however, the preferred support is substantially pure gamma- or eta-alumina. Preferred _ g _ 108~)689 carrler materials have an apparent bulk density of about 0 3 to about 0.7 gm/cc and surface area characteristics such that the average pore diameteris about 20 to about 300 Angstroms, the pore volume is about 0.1 to about 1 ml/gm and the surface area is about 100 to about 500 m /gm~ Excellent results are obtalned with a gamma-alumina carrier material which is used ln the form of spherical particles having a relatively small dlameter for example, about 106 mm (1/16 inch), an apparent kulk density of about 0~5 gm/cc~ a pore volume of about 0 4 ml/gm~ and a surface area of about 175 m2/gm~
The preferred alumina carrier material may be synthetically prepared or natural occurring. Whatever type of alumina is employed it may be activated prior to use by one Gr more treatments including drying~ calcination~ or iS steamingO ar.d it may be in a form known as activated alumina, activated alumina of commerce, porous alumina, or alumina gel. For example, the alumina carrier may be prepared by adding a suitable alkaline reagent, such as ammonium hydroxide to a salt of aluminum such as aluminum chloride or aluminum nitrate, to form an aluminum hydroxide gel which upon drying and calclning is converted tc alumina. The alumina carrier may be formed in any desired shape such as spheres, pills, - cakes, extrudates, powders, or granules, and utllized in any desired size. For the purpose of the present invention a particularly preferred form of alumina is the sphere.
1080~9 Alumina spheres may be continuously manufactured by the well known oil drop method, which comprises forming an alumina hydrosol, combining the hydrosol with a suitable gelling agent and dropping the resultant mixture into an oil bath S maintained at elevated temperatures. The droplets remain in the oil bath until they set and form hydrogel spheres. The spheres are then washed, dried and calcined. The final spheres are crystalline gamma-alumina.
One essential constituent of the catalyst of the present invention is a tin component. This component may be present as elemental metal or as a chemical compound such as the oxide, sulfide or halide. Preferably, the composite contains from about 0.01 to about 5 wt % tin and more preferably from 0.1 to 1 wt % tin. The tin component may be incorporated in the catalytic composite in any suitable manrer such as by coprecipitation or cogellation with the porous carrier materlal, ion exchange with the carrier material, or impregnation of the - carrier material either after or before it is dried and calcined.
- Any conventional method for incorporating the tin component in a catalytic composite may be used. The particular method used is not an essential feature of the present invention. One method involves coprecipitating the tin component with the preferred carrier material, alumina. This method involves - the addition of soluble tin compounds such as stannous or stannic lO~V~3 halide to the alumina hydrosol, combining th e hydrosol with a suitable gelling agent and then dropping the resulting mixture into an oil bath, aging, washing, drying and calcining as explained in detail hereinbefore. The resulting catalytic composite contains an intimate combinati~ of alumina and stannic oxide. A preferred method of incorporating the tin component into the catalytic composite involves using a soluble, decomposable compound of tin to impregnate the porous carrier material. Thus, the tin component may be added to the carrier materal by commingling the latter with an aqueous, solution of suitable tin salt or water soluble compound of tin such as stannous bromide, stannous chloride, stannic chloride, stannic chloride pentahydrate, stannic chloride tetrahydrate, stannic chloride trihydrate, stannic chloride diamine, stannic trichloride brDmide, stannic chromate, stannous fluoride, stannic fluoride, stannic iodide, stannic sulfate, stannic tartrate, and the like compounds.
Use of a tin chloride is preferred as this facilitates incor-poration of at least a minor amount of the preferred halogen component in a single step. The tin component may be impregnated either prior to, simultaneously with, or after the other metallic components are added to the carrier material.
1080~9 Excellent results are obtained when the tin component is impregnated simultaneously with the other metallic compo-nents. A preferred impregnation solution contains chloro-platinic acid, hydrogen chloride, perrhenic acid and stannous or stannic chloride. Following the impregnation step, the resulting composite is dried and calcined as explained hereinafter.
As indicated above, a second essential component of - the catalyst of the invention is the platinum group component.
The platinum group component preferably will be platinum, but may be any of the other members of the group, that is, palladium, ruthenium, osmium, or iridium. The platinum group compon~ t may exist within the final catalytic composite as a compound such as an oxide, sulfide, halide, or as an elemental metal.
Generally, the amount of the platinum group component present in the final catalyst composite is small compared to the quantities of the other components combined therewith.
Generally it ~ 11 comprise from about 0.01 to about 1 wt % of the final catalytic composite, calculated on an elemental basis. Fxcellent results are obtained when the catalyst con-tains about 0.1 to about 0.8 wt % of the platinum group metal.
~08~)ti89 The platinum group component may be incorporated in the catalytic composite in any suitable manner such as co-precipitation or cogellation with the preferred carrier material, ion-exchange, or impregnation. The preferred method involves the utilization of a soluble, decomposable compound of a platinum group metal to impregnate the carrier material.
Thus, the platinum group component may be added to the support by commingling the latter with an aqueous solution of chloro-platinic acid. Other water-soluble compounds of platinum may be employed, such as ammonium chloroplatinate, or dinitrodiamino platinu~. A platinum chloride compound, such as chloroplatinic acid, is preferred since it facilitates the incorporation of both the platinum component and at least a minor quantity of the preferred halogen component in a single step.
.
iO8~9 Hydrogen chloride lS also generally added to the impregnation solution to further facilitate the incorporation of the halogen component. It is generally preferred to impregnate the carrier material after it has been calcined, to minimize the risk of washing away the valuable platinum metal compounds~ However, in some cases it may be advantageous to impregnate the carrier material when it is in a gelled state Following the impreg--r.ation~ the impregnated support is dried and subjected to a high temperature calcination or oxidation technique~
Another essential component of the catalyst of the present invention is the rhenium componentO This component may be present as elemental metal, as a chemical compound such as the oxide, sulfide or halide, or as a physical or chemical combination with the porous carrier materlal and/or other components of the cat~lytic.composite. The rhenium component is preferablY utilized ln an amount which provides ln the final catalytic composite from about O o Ol to about 1 wt % rhenium, calculated on an elemental basis The rhenium component may be incorporated in the catalytic composite in any suitable manner and at any stage in the preparation of the catalyst. It is generally advisable to incorporate the~rhenium component in an impregnation step - after the porous carrier material has been formed in order that the expensive metal will not be lost due to washing and purification treatments which may be applied to the ~ 15 -108~)689 carrier material during the course of its production. Although any suitable method can be utilized to incorporate the rhenium component, the preferred procedure involves impregnation of the porous carrier material. The impregnatlon solution may, in general, be a solution of a decomposable rhenium salt such as ammonium perrhenate~ sodium perrh~nate~ potassium perrhenate, and the like salts~ Alternatively, solutions of rhenium halides, such as rhenium chloride, may be used. The pre-ferred impregnation solution is an aqueous solution of perr-henic acid. The porous carrier material may be impregnated with the rhenium component either prior to, simultaneously with~ or after the other components mentioned herein are combined therewith. Best results are ordinarlly achieved when the rhenium component is impregnated simultaneously lS with the other metallic components... In fact~ excellent results have been obtained with a one step impregnation procedure utilizing as an impregnation solutionO an aqueous solution of chloroplatinic acid, perrhenic acid, hydrochloric acidO and stannic chloride.
Although not essential, it is generally preferred to incorporate a halogen component into the catalytic com-posite of the present invention. The precise chemistry of the association of the halogen component with the carrier material is not entirely knownO It is customary that the halogen component is combined with the car-rier material or with the other ingredients of the catalyst. This combined 108~)~89 halogen may be either fluorine, chlorine, iodine, bromine, or mixtures thereof. Fluorine, and particularly chlorine, are preferred~ The halogen may be added to the carrier material either during preparat~on of the support or before or after the addition of the other components. For example, the halogen may be added at any stage of the preparation of the carrier material, or the calcined carrier material, as an aqueous solution of an acid such as hydrogen fluoride, hydrogen chloride, hydrogen bromide or the like. The halogen component or a portion thereof may be composited with the carrier material during the impregnation of the latter with the platinum group component; for example, by using a mixture of chloroplatinic acid and hydrogen chloride. The alumina hydrosol utilized to form the preferred aIumina carrier material may also contain halogen and thus contribute at least a portion of the halogen component to the final composite. For reforming; the halogen is combined with the carrier material in an amount which yields a final composite containing from about 0.1 to about -~ 1.5 wt % and preferably about 0O5 to about 1 2 wt % of halogen, calculated on an elemental basis. For utilization as isomeri-zation or hydrocracking catalyst, it is generally preferred to utilize relatively larger amounts of halogen, -- ranging -~ up to about 10 wt % halogen calculated on an elemental basis, and more preferably about 1 to about 5 wt %.
Regarding the amounts of the various metallic com-ponents of the subject catalyst, it is preferable to specify the amounts of the rhenium component and of the tin 108V~i89 component as a function of the amount of the platinum group component. On this basis, the amount of the rhenium component is selected sothat the atomic ratio of the platinum group metal to rhenium contained in the composite is from about 0.05:1 to about 2.75:1 with a preferred range of from about 0.25:1 to 2:1. Similarly, the amount of the tin component is selected to produce a composite containing an a'omic ratio '.. of platinum group metal to tin of about 0.1:1 to about 3:1, with a preferred range of from about 0.25:1 to 2:1.
Another significant parameter for the subject catalyst is the "total metals content" which is the sum of the platinum group component, the rhenium component, and the tin component, calculated on an elemental metal basis. Good results are ordinarily obtained with the subject catalyst when this parameter is fixed at a value of about 0.03 to about 3 wt ~, with best results achieved at a metals loading . - of about 0.15 to.about 2 wt %.-A particularly preferred catalytic composlte com-prises a platinum component, a rhenium component, a tin component, and a halogen component with an alumina carrier - material, in amounts which provide a composite containing : about 0.1 to about 1.5 wt % halogen, about 0.01 to about 1 wt % platinum, about 0.01 to about 1 wt % rhenium, and about 0.01 to about 5 wt % tin. Accordingly, specific .~ 25 examples of especially preferFed càtalytic composites are tabulated below, the concentrations indicated being on an ~' ..
iO~ 89 elemental basis:
Min Max Catalyst Wt % Wt % Wt % Wt % Wt %
No. Tin Rhenium PlatinumHaloqenHaloqen l 0.5 0.5 0.75 0.1 1.5
In another aspect, the present invention comprehends the improved processes that are provlded by the use of a caialytic composite comprising a platinum group component, a rhenium component, and a tin component with a porous carrier material; specificallyO an improved reforming process which ~15 utillzes the subject catalyst to improve activity, selectivity, and stability characteristics.
Composi~es having a hydrogenation-dehydrogenation function and a cracking function are widely used today as catalysts in many industries, such as the petroleum and petro-chemical industryg to accelerate a wide spectrum of hydrocarbon c-nversion reactions. Generally, the cracking function is thought to be associated with an acid-acting material of the ., .
108~)~85~
porous, adsorptive, refractory oxide type whlch is utilized as the support or carrier for a heavy metal component~ such as the metals or compounds of metals of Group V through VIII
of the Perlodic Table, to which lS generally attributed the hydrogenation-dehydrogenatlon function.
These catalytic composites are used to accelerate a wide variety of hydrocarbon conversion reactions such as ~hydrocracking~ isomerization~ dehydrogenation~ hydrogenation, desulfurizationt cyclization, aikylation; polymerlzation, iO cracking and hydroisomerization. In many cases, the commer-cial applications of these catalysts are in processes where more than one of these reactions is proceeding simultaneously.
An example of this type of process is reforming wherein a hydrocarbon feed stream containing paraffins and naphthenes is subjected to condltions which promote dehydrogenation of naphthenes to aromatics, dehydrocyclization of paraffins to aromatics, lsomerization of paraffins and naphthenes~ hydro-cracking of naphthenes and paraffins and the like reactions, to produce an octane-rich or aromatic-rich product stream.
Another example is a hydrocracking process wherein catalysts of this type are utilized to effect selective hydrogenation and cracking of high-molecular--weight, unsaturated materiais, selective hydrocracking of high molecular weight materials, and other like reactions, to produce a generally lower boiling, more valuable output stream~ Yet another example is an isomerization process wherein a hydrocarbon fraction which is -- - .
1080~i89 relatitely rich in straight-chain paraffin components is con-tacted with a dual-function catalyst to produce an output stream rich in isoparaffin compounds.
Regardless of the reaction involved or the particular process involved, it is of critical importance that the dual-functlon catalyst exhibit not only the capabil~ty to initially perform its specified functions, but also that it has the capability to perform them satisfactorily for prolonged periods of time. The analytical terms used in the art to measure how well a particular catalyst performs its intended functions in a particular hydrocarbon reaction environment are activity, selectivityf and stability. And for purposes of discussion here, these terms are conveniently defined for a given charge stock as follows: (1) activity is a measure of the catalyst's L5 ability to convert hydrocarbon reactants into products at a specified severity level where severity level means the condi-tions used -- that is, the temperature, pressure, contact time, and presence of diluents such as hydrogen, (2) selectivity refers to the amount of desired product or products obtained 'O relative to the amount of reactants converted; (3) stability refers to the rate of change with time of the activity and selectivity parameters -- the smaller rate implying the more stable catalyst. In a reforming process, for example, activity commonly refers to the amount of conversion of a given charge '5 stock at a specified severity level and is-typically measured by octane number of the C5+ product stream; selectivity refers 10806~
to the amount o~ C5+ yield that lS obtalned at the particular severity level and stablllty refers to the rate of change with time of activity~ as measured by octane number of C5+
product, and of selectlvlty~ as measured by C5+ yield.
Generally a continuous reforming process is run to produce a constant octane C5+ product with severlty level being cor.tinuously adjusted to attain thls result. Furthermore, the severity level is for this process usually varied by ad-~ sting the converslon temperature in the reaction zone so that in point of fact, the rate of change of activity finds response in the rate of change of conversion temperatures and char.ges in thls last parameter are customarily taken as ir.dicative of activlty stabilityc As is well known to those skilled in the art, the .5 prlncipal cause of observed deactivation or instabllity of a dual-function catalyst when used in a hydrocarbon conversion reactlon is that coke forms on the surface of the catalyst.
More specifically, in these hydrocarbon conversion processes, the conditions utilized ~ypically result in the formation of heavy, high molecular weight, black, solid or semi-solid, - carbonaceous material which coats the surface of the catalyst and reduces its activity by shieldlng its active sites from the reactants. In other words~ the performance of this dual-~ function catalyst is sensitive to the presence of carbonaceous --~25 deposits on the surface of the catalyst. Accordlngly, the major problem facing workers in this area of the art is the development of more active and selective catalytic composites that are not as sensitive to the presence of these carbonaceous materials and/or have the capability to suppress the rate of the formation of these carbonaceous materials on the catalyst.
Viewed in terms of performance parameters, the problem is to develop a dual-function catalyst having superior activity, selectivity, and stability. In particular, for a reforming process the problem is typically expressed in terms of shifting and stabilizing the C5+ yield-octane relationship -- C5+ yield being representative of selectivity and octane being propor-tional to activity.
The present invention provides a dual-function catalytic composite which possesses improved activity, selectivity, and stability when employed for the conversion of hydrocarbons in processes for isomerization, hydroisomeri-zation, dehydrogenation, desulfurization, denitrogenization, hydrogenation, alkylation, dealkylation, hydrodealkylation, transalkylation, cyclization, dehydrocyclization, cracking, hydrocracking, reforming, and the like. In particular, a composite comprising a platinum group component, a rhenium component, and a tin component with a porous refractory carrier material enables the performance of hydrocarbon conversion processes utilizing dual-function catalysts to be substantially improved. Moreover, a catalytic composite comprising catalytically effective amounts of a platinum :108V~
component, a tin component a rhenium component, and a halogen component with an alumina carrier material can be utilized to substantially improve the performance of a reforming process which operates on a gasoline-boiling-range fraction to produce a high-octane reformate. In the case of a reforming process, the principal advantage associated with the use of the novel catalyst of the present invention involves the capability to operate in a stable manner in a high severity operation fo~ example, a low pressure reforming process designed to produce a Cs+ reformate having an octane of about 100 F-l clear.
As indicated, the present invention involves the discovery that the addition of a tin component and a rhenium component to a dual-function hydrocarbon conversion catalyst containing a platinum group component enables the performance characteristics of the catalyst to be sharply and materially improved O
It is,accordingly, one object of the present ~ inventlon to provide a hydrocarbon conversion process utilizing -~ a novel catalyst having superior performance characteristics.
~20 A second object is to provide a catalyst having dual-function hydrocarbon conversion performance characteristics that are relatively insensitive to the deposition of hydrocarbonaceous material thereon. A third object is to provide preferred methods of preparation of this catalytic composite which insures the achievement and maintenance of its properties.
Another object is to provide an improved reforming catalyst lO~Vtil~
having superior activity, selectivity, and stability. Yet another object is to provide a dual-function hydrocarbon conversion catalyst which utilizes a combination of a rela-tlvely inexpensive component, tin, and a relatively expensive component, rhenium~ to promote a platinum metal component.
Accordingly, the present invention provides a process for the conversion of a hydrocarbon, which comprises subjecting said hydrocarbon to contact at hydrocarbon con-`10 version conditions with a catalytic composite comprising a platinum group component, a rhenium component, and a tin component with a porous carrier material. The porous carrier material is a porous, refractory material such as a refractory inorganic oxide, and the tin component, the rhenium component, and the platinum group component are usually utilized in relatively small amounts which are effective to promote the desired hydrocarbon conversion reaction.
The invention further provides a catalytic com-posite comprising a platinum component, a rhenium component, and a tin component, with an alumina carrier material.
These components are preferably present in the composite in the following amounts, on an elemental basis; from about 0.01 to about 1 wt % platinum, from about 0.01 to about 1 wt YO rhenium, and from about 0.01 to about 5 wt % tin.
The composite may also contain a-halogen component in amount up to 10 wt %, but preferably in an amount within ~o~vtj~
the range from about 0.1 to about 1.5 wt % (elemental basis).
According to a further feature of the invention, the composite is reduced with hydrogen under substantially water-free conditions prior to use thereof in the conversion of hydrocarbons. The pre-reduced catalytic composite may be combined with a sulfur component in an amount which incor-porates therein from about 0.05 to about 0.5 wt % sulfur, calculated on an elemental basis.
A preferred embodiment of the invention provides a process for reforming a gasoline fraction which comprises contacting the gasoline fraction and hydrogen with the catalytic composite described above at reforming conditions selected to produce a high-octane reformate.
As indicated above, the catalyst of the present invention comprises a porous carrier material or support having combined therewith catalytically effective amounts of a platinum group component, a rhenium component, a tin component, and in the preferred case a halogen component. Considering first the porous carrier material utilized in the present invention, it is preferred that the material be a porous, adsorptive, high-surface-area support having a surface area of about 25 to about 500 m2/gm. The - porous carrier material should be relatively refractory to - the conditions utilized in the hydrocarbon conversion process, - 25 and it is intended to include within the scope of the present invention carrier materials which have traditionally been utilized in dual-functlon hydrocarbon conversion catalysts such as: (1) activated carbon, coke, or charcoal, (2) silica or silica gel, silicon carbide. clays, and silicates including those synthetically prepared and naturally occurring. which may or may not be acid treatedj for example, Attapulgus clay, ^hlna clayA diatomaceous earthf fuller~s earth, kaol1n, and kieselguhr; (3) ceramlcs, porcelain. crushed firebrick, bauxlte;
(4) refractory inorganic oxldes sucn as alumina, titanium diox'.de, zirconium dioxide, chromium oxide, zinc oxlde, magnesiaC thoria~ boria, silica-alumina, slllca-magnesia, chromia-alumina~ alumina-boria~ and sllica-zirconia; (5) crystalline aluminosillcates such as naturally occurring or synthetlcally prepared mordenite and/or faujasite, either in the hydrogen form or in a form which has been treated with mu.ltivalent cations; and, (6) combinatlons of these groups. The preferred porous carrier materials for use in the present invention are refractory inorganic oxides, with best results obtained with an alumina carrier material~
Suitable alumina materials are the crystalline aluminas known as the gamma-, eta-~ and theta-aluminas with gamma-or eta-alumina giving best results. In addition. in some embodiment~ the alumina carrier material may contain minor proportions of other well known refractory inorganic oxides such as silica, zirconia, and magnesia, however, the preferred support is substantially pure gamma- or eta-alumina. Preferred _ g _ 108~)689 carrler materials have an apparent bulk density of about 0 3 to about 0.7 gm/cc and surface area characteristics such that the average pore diameteris about 20 to about 300 Angstroms, the pore volume is about 0.1 to about 1 ml/gm and the surface area is about 100 to about 500 m /gm~ Excellent results are obtalned with a gamma-alumina carrier material which is used ln the form of spherical particles having a relatively small dlameter for example, about 106 mm (1/16 inch), an apparent kulk density of about 0~5 gm/cc~ a pore volume of about 0 4 ml/gm~ and a surface area of about 175 m2/gm~
The preferred alumina carrier material may be synthetically prepared or natural occurring. Whatever type of alumina is employed it may be activated prior to use by one Gr more treatments including drying~ calcination~ or iS steamingO ar.d it may be in a form known as activated alumina, activated alumina of commerce, porous alumina, or alumina gel. For example, the alumina carrier may be prepared by adding a suitable alkaline reagent, such as ammonium hydroxide to a salt of aluminum such as aluminum chloride or aluminum nitrate, to form an aluminum hydroxide gel which upon drying and calclning is converted tc alumina. The alumina carrier may be formed in any desired shape such as spheres, pills, - cakes, extrudates, powders, or granules, and utllized in any desired size. For the purpose of the present invention a particularly preferred form of alumina is the sphere.
1080~9 Alumina spheres may be continuously manufactured by the well known oil drop method, which comprises forming an alumina hydrosol, combining the hydrosol with a suitable gelling agent and dropping the resultant mixture into an oil bath S maintained at elevated temperatures. The droplets remain in the oil bath until they set and form hydrogel spheres. The spheres are then washed, dried and calcined. The final spheres are crystalline gamma-alumina.
One essential constituent of the catalyst of the present invention is a tin component. This component may be present as elemental metal or as a chemical compound such as the oxide, sulfide or halide. Preferably, the composite contains from about 0.01 to about 5 wt % tin and more preferably from 0.1 to 1 wt % tin. The tin component may be incorporated in the catalytic composite in any suitable manrer such as by coprecipitation or cogellation with the porous carrier materlal, ion exchange with the carrier material, or impregnation of the - carrier material either after or before it is dried and calcined.
- Any conventional method for incorporating the tin component in a catalytic composite may be used. The particular method used is not an essential feature of the present invention. One method involves coprecipitating the tin component with the preferred carrier material, alumina. This method involves - the addition of soluble tin compounds such as stannous or stannic lO~V~3 halide to the alumina hydrosol, combining th e hydrosol with a suitable gelling agent and then dropping the resulting mixture into an oil bath, aging, washing, drying and calcining as explained in detail hereinbefore. The resulting catalytic composite contains an intimate combinati~ of alumina and stannic oxide. A preferred method of incorporating the tin component into the catalytic composite involves using a soluble, decomposable compound of tin to impregnate the porous carrier material. Thus, the tin component may be added to the carrier materal by commingling the latter with an aqueous, solution of suitable tin salt or water soluble compound of tin such as stannous bromide, stannous chloride, stannic chloride, stannic chloride pentahydrate, stannic chloride tetrahydrate, stannic chloride trihydrate, stannic chloride diamine, stannic trichloride brDmide, stannic chromate, stannous fluoride, stannic fluoride, stannic iodide, stannic sulfate, stannic tartrate, and the like compounds.
Use of a tin chloride is preferred as this facilitates incor-poration of at least a minor amount of the preferred halogen component in a single step. The tin component may be impregnated either prior to, simultaneously with, or after the other metallic components are added to the carrier material.
1080~9 Excellent results are obtained when the tin component is impregnated simultaneously with the other metallic compo-nents. A preferred impregnation solution contains chloro-platinic acid, hydrogen chloride, perrhenic acid and stannous or stannic chloride. Following the impregnation step, the resulting composite is dried and calcined as explained hereinafter.
As indicated above, a second essential component of - the catalyst of the invention is the platinum group component.
The platinum group component preferably will be platinum, but may be any of the other members of the group, that is, palladium, ruthenium, osmium, or iridium. The platinum group compon~ t may exist within the final catalytic composite as a compound such as an oxide, sulfide, halide, or as an elemental metal.
Generally, the amount of the platinum group component present in the final catalyst composite is small compared to the quantities of the other components combined therewith.
Generally it ~ 11 comprise from about 0.01 to about 1 wt % of the final catalytic composite, calculated on an elemental basis. Fxcellent results are obtained when the catalyst con-tains about 0.1 to about 0.8 wt % of the platinum group metal.
~08~)ti89 The platinum group component may be incorporated in the catalytic composite in any suitable manner such as co-precipitation or cogellation with the preferred carrier material, ion-exchange, or impregnation. The preferred method involves the utilization of a soluble, decomposable compound of a platinum group metal to impregnate the carrier material.
Thus, the platinum group component may be added to the support by commingling the latter with an aqueous solution of chloro-platinic acid. Other water-soluble compounds of platinum may be employed, such as ammonium chloroplatinate, or dinitrodiamino platinu~. A platinum chloride compound, such as chloroplatinic acid, is preferred since it facilitates the incorporation of both the platinum component and at least a minor quantity of the preferred halogen component in a single step.
.
iO8~9 Hydrogen chloride lS also generally added to the impregnation solution to further facilitate the incorporation of the halogen component. It is generally preferred to impregnate the carrier material after it has been calcined, to minimize the risk of washing away the valuable platinum metal compounds~ However, in some cases it may be advantageous to impregnate the carrier material when it is in a gelled state Following the impreg--r.ation~ the impregnated support is dried and subjected to a high temperature calcination or oxidation technique~
Another essential component of the catalyst of the present invention is the rhenium componentO This component may be present as elemental metal, as a chemical compound such as the oxide, sulfide or halide, or as a physical or chemical combination with the porous carrier materlal and/or other components of the cat~lytic.composite. The rhenium component is preferablY utilized ln an amount which provides ln the final catalytic composite from about O o Ol to about 1 wt % rhenium, calculated on an elemental basis The rhenium component may be incorporated in the catalytic composite in any suitable manner and at any stage in the preparation of the catalyst. It is generally advisable to incorporate the~rhenium component in an impregnation step - after the porous carrier material has been formed in order that the expensive metal will not be lost due to washing and purification treatments which may be applied to the ~ 15 -108~)689 carrier material during the course of its production. Although any suitable method can be utilized to incorporate the rhenium component, the preferred procedure involves impregnation of the porous carrier material. The impregnatlon solution may, in general, be a solution of a decomposable rhenium salt such as ammonium perrhenate~ sodium perrh~nate~ potassium perrhenate, and the like salts~ Alternatively, solutions of rhenium halides, such as rhenium chloride, may be used. The pre-ferred impregnation solution is an aqueous solution of perr-henic acid. The porous carrier material may be impregnated with the rhenium component either prior to, simultaneously with~ or after the other components mentioned herein are combined therewith. Best results are ordinarlly achieved when the rhenium component is impregnated simultaneously lS with the other metallic components... In fact~ excellent results have been obtained with a one step impregnation procedure utilizing as an impregnation solutionO an aqueous solution of chloroplatinic acid, perrhenic acid, hydrochloric acidO and stannic chloride.
Although not essential, it is generally preferred to incorporate a halogen component into the catalytic com-posite of the present invention. The precise chemistry of the association of the halogen component with the carrier material is not entirely knownO It is customary that the halogen component is combined with the car-rier material or with the other ingredients of the catalyst. This combined 108~)~89 halogen may be either fluorine, chlorine, iodine, bromine, or mixtures thereof. Fluorine, and particularly chlorine, are preferred~ The halogen may be added to the carrier material either during preparat~on of the support or before or after the addition of the other components. For example, the halogen may be added at any stage of the preparation of the carrier material, or the calcined carrier material, as an aqueous solution of an acid such as hydrogen fluoride, hydrogen chloride, hydrogen bromide or the like. The halogen component or a portion thereof may be composited with the carrier material during the impregnation of the latter with the platinum group component; for example, by using a mixture of chloroplatinic acid and hydrogen chloride. The alumina hydrosol utilized to form the preferred aIumina carrier material may also contain halogen and thus contribute at least a portion of the halogen component to the final composite. For reforming; the halogen is combined with the carrier material in an amount which yields a final composite containing from about 0.1 to about -~ 1.5 wt % and preferably about 0O5 to about 1 2 wt % of halogen, calculated on an elemental basis. For utilization as isomeri-zation or hydrocracking catalyst, it is generally preferred to utilize relatively larger amounts of halogen, -- ranging -~ up to about 10 wt % halogen calculated on an elemental basis, and more preferably about 1 to about 5 wt %.
Regarding the amounts of the various metallic com-ponents of the subject catalyst, it is preferable to specify the amounts of the rhenium component and of the tin 108V~i89 component as a function of the amount of the platinum group component. On this basis, the amount of the rhenium component is selected sothat the atomic ratio of the platinum group metal to rhenium contained in the composite is from about 0.05:1 to about 2.75:1 with a preferred range of from about 0.25:1 to 2:1. Similarly, the amount of the tin component is selected to produce a composite containing an a'omic ratio '.. of platinum group metal to tin of about 0.1:1 to about 3:1, with a preferred range of from about 0.25:1 to 2:1.
Another significant parameter for the subject catalyst is the "total metals content" which is the sum of the platinum group component, the rhenium component, and the tin component, calculated on an elemental metal basis. Good results are ordinarily obtained with the subject catalyst when this parameter is fixed at a value of about 0.03 to about 3 wt ~, with best results achieved at a metals loading . - of about 0.15 to.about 2 wt %.-A particularly preferred catalytic composlte com-prises a platinum component, a rhenium component, a tin component, and a halogen component with an alumina carrier - material, in amounts which provide a composite containing : about 0.1 to about 1.5 wt % halogen, about 0.01 to about 1 wt % platinum, about 0.01 to about 1 wt % rhenium, and about 0.01 to about 5 wt % tin. Accordingly, specific .~ 25 examples of especially preferFed càtalytic composites are tabulated below, the concentrations indicated being on an ~' ..
iO~ 89 elemental basis:
Min Max Catalyst Wt % Wt % Wt % Wt % Wt %
No. Tin Rhenium PlatinumHaloqenHaloqen l 0.5 0.5 0.75 0.1 1.5
2 0.1 0.1 0.1 0.5 1.2
3 0.375 0.375 0.375 0.5 1.2
4 0.12 0.1 0.2 0.5 1.2 0.25 0.25 0.25 0.5 1.2 6 0.2 0.2 0.2 0.5 1.2 For all of the above mentioned composites the preferred carrier material comprises alumina.
The final catalyst generally is dried at a tempera-ture of about 93C (200F) to about 316C (600F) for a period of from about 2 to about 24 hours or more, and finally calcined at a temperature of about 371C (700F) to about 593C (1100F) in an air atmosphere for a period of about 0.5 to about 10 hours to convert the metallic components substantially to the ~xide form. In the case where a halogen component is utilized in the catalyst, best results are generally obtained when the halogen content of the catalyst -` is adjusted during the calcination step by including a hal-ogen or a halogen-containing compound in the air atmosphere utiiized. In particular, when the halogen component of the catalyst is chlorine, it is preferred to use a mole ratio of 10~ 8~
H20 to HCl o~ about 20:1 to about 100:1 during at least a portion of the calcination step in order to adjust the final chlorine content of the catalyst to a range of about 0.5 to about 1.2 wt %.
It is preferred that the resultant calcined catalytic composite be subjected to a reduction step prior to its use in the conversion of hydrocarbons. This step is designed to insure a uniform and finely divided dis-persion of the metallic components throughout the carrier material. Preferably, substantially pure and dry hydrogen containing less than 20 vol ppm H20 is used as the reducing agent. The reducing agent is contacted with the calcined catalyst at a temperature of about 427C (800F) to about 649C (1200F) and for a period of time of about 0.5 to 10 hours or more, effective to substantially reduce the metallic components to their elemental state. This reduction treatment may be performed in situ as part of a start-up sequence if precautions are taken to pre-dry the plant to a substantially water-free state and if substantially water-free hydrogen is used.
The resulting reduced catalytic composite may, in some cases, be beneficially subjected to a presulfiding operation designed to lncorporate in the catalytic composite from about 0.05 to about 0.5 wt % sulfur calculated on an elemental basis. Preferably, this presulfiding treatment ' 108~)~89 takes place in the presence of hydrogen and a suitable sulfur-containing compound such as hydrogen sulfide, lower molecular weight mercaptans, or organic sulfides. Thls procedure com-prises treating the reduced catalyst with a sulfiding gas, such as a mixture of hydrogen and hydrogen sulfide having about 10 moles of hydrogen per mole of hydrogen sulfide, at conditions which effect the desired incorporation of sulfur, generally including a temperature ranging from about 10C (50F) up to about 593C (1100 F). It is generally a good practice to perform this presulfiding step under sub-stantially water-free conditions.
According to the present invention, a hydrocarbon charge stock and hydrogen are contacted with a catalyst of the type described above in a hydrocarbon conversion zone.
Th~s contacting may be accomplished by using the catalyst in a fixed bed system, a moving bed system, a fluidized bed system, or in a batch type operation however, in view of the danger of attrition losses of the valuable catalyst, and of well known operational advantages, it is preferred to use a fixed bed system. In this system, a hydrogen-- rich gas and the charge stock are preheated to the desired reaction temperature and passed into a conversion zone con-taining a fixed bed of the aforementioned catalyst. The conversion zone may comprise one or more separate reactors with suitable means therebetween to insure that the desired ~080~i8~
conversion temperature is maintained at the entrance to each reactor. The reactants may be contacted with the catalyst bed in either upward, downward, or radial flow fashion with the latter being preferred. The reactants may be in the liquid phase, a mixed liquid-vapor phase, or a vapor phase when they contact the catalyst, with best results obtained in the vapor phase.
When the catalyst of the present invention is used in a reforming operation, the reforming system will comprise one or more separate reactors containing fixed beds of catalyst with suitable heating means therebetween to compensate for the endothermic nature of the reaction that takes place in each catalyst bed.` The hydrocarbon feed to the reforming system will comprise hydrocarbon fractions containing naph-lS thenes and paraffins boiling within the gasoline rangeD The preferred charge stocks are those consisting essentially of naphthenes and paraffins, although aromatics may also be present. This preferred class includes straight run gaso-lines, natural gasolines, synthetic gasolines, as well as thermally or catalytically cracXed gasolines or higher boiling fractions thereof, or mixtures of these. The gasoline charge stock may be a full boiling gasoline having an initial boiling point of from about 10 C (50 F) to about 66C (150~F) and an end boiling point within the range of from about 163C (325F) to about 219C (425 F), or may be a selected fraction thereof which generally will be a higher boiling fraction commonly .~ .
10~ 89 re~erred to as a heavy naphtha -- ror example, a naphtha boiling in the rar.ge of C7 ~o 204C (400F). In some cases, lt is also advantageous to charge pure hydrocarbons or mixtures o~ hydrocarbons that have been extracted rrom hydrocarbon distillates~ for example, straight chain paraffins, which ar~ tc be converted tO aromatics~ It is preferred that these charge stocks be treated by conventional catalytic pretreatment methods such as hydrorefining~ hydrotreating, or h~drcdesulfurizatlo-. to remcve s~bstantially a~l sulfurous, 0 - nitrogenous and water-ylelding conta~inants and to saturate any olefins present.
When catalyst of the present invention is used to pro.~ote isomerization~ the charge stock can be~ for example, a paraffiric stocX rich in C4 to C8 r.ormal paraffins, n-butar.e-rich stcck, n-hexane-rich stock or a mixture of xylene isomers as well as alkylaromatics and naphthenes. In hydrocracking embodiments the charge stock wlll ke typically a gas oil or heavy cracked cycle oil.
Likewise, pure hydrocarbons or substantially pure hydro-!0 carbor.s can be converted to more valuable products by using the catalyst of the present invention in any of the hydro-carkon conversion processes kncwn to the art that use a do31-function catalyst.
In the case or reforming it is sometlmes preferred that the novel catal,~tic coclposite be utlllzed in a sub-stantially water-rree environ.T,ent To achleve thls condition - '.
108~)689 n the reforming zone requires control of the water content of the charge stock and of the hydrogen stream charged to the conversion zone. Best results are cbtained when the total amount of water (expressed as weight of equivalent water ln the charge stock) enter ng the conversion zone rrom any source is less than 50 and preferably less than 20 wt ppm~ The charge stock can be dried by using any con-ventional solid adsorbent selective for water, for instance, sodium or calcium crystalline aluminosilicates, silica gel, actlvated alumina~ molecular sieves, anhydrous calcium sulfate, -high surface area sodium and the like adsorbents. Similarly, the water content of the charge stock may be adjusted by suitable stripping operations in a fractionation column or like device. And ln some cases, a comblnation of adsorbent drying and dlstillation drying may be used advantageously to effect almost complete removal of water from the chaxge stockO Pref-erably, the charge stock is drled to less than 20 ppm of water, In general, it is preferred to dry the hydrogen stream entering the hydrocarbon conversion zone to lO vol ppm of water or less. This can be conveniently accompllshed by contacting the hydroger. stream with a sultable desiccant such as those mentioned above.
In the reforming embodiment~ an effluent stream is wlthdrawn from the reforming zone and passed through cooling means to a separation zone, typically maintained at about . -: .
~08V~89 -~C (25F) to 66C (150F), wherein hydrogen-rich gas is separated from high octane liquid product, commonly called unstabilized reformate. Preferably, at least a portion of this hydrogen-rich gas is withdrawn from the separating zone and passed over an adsorbent selective for water. The resultant substantially water-free hydrogen stream is then recycled to the reforming zoneO The liquid phase from the separating zone is then withdrawn and treated in a fractionating system to adjust the butane concentration and volatility of the resulting reformate.
The conditions utilized in the numerous hydro-carbon conversion embodimentsofthe present invention are those customarily used in the art for the particular reac-tion or combination of reactions to be effected~ For instance, alkylaromatic and paraffin isomerization conditions include:
a temperature of about 0C (32F) to about 538C (1000F) and preferably about 24C (75F) to about 316 C (600F); a pressure of atmospheric to about lO0 atmospheres; a hydrogen to hydrocarbon mole ratio of about 0.5:1 to about 20:1, and a liquid hourly space velocity (LHSV) (calculated on the - basis of equivalent liquid volume per hour of the charge stock contacted with the catalyst divlded by the volume of catalyst) of about 0O2 to 10~ Dehydrogenation conditions include: a temperature of about 371C (700F) to about 677C (1250F), a pressure of about 0.1 to about lO atmos-pheres, an LHSV of about l to about 40, and a hydrogen-to-~08~f~89 hydrocarbon mole ratio of abo_t 1.1 to about 20:1. Hydro-cracki~.g conditions include: a pressure of about 35 atm (500 pSlg) to about 205 atm (3000 pslg), a temperature of abo~t 204C (4000F) to about 482C (900F); an LHSV of about S 0.1 to aboat lO~and hydrogen circulation rates of about i,~ to 17~0 standard cubic meters per cubic meter (cm/cm) of liquld charge (corresponding to from about 1000 to 10,000 SCF per barrel of charge).
In the reforming embodiment of the present invention the pressure utilized is selected from the range of about atmosphesic to abo~t 69 atm (1000 psig), with the preferred pressure range belng about 7.8atm (~ psig) to about 41.8 atm (600 psig). Particularly gocd resul~s are obtained at low pressure; namelyc a pressure of from about 6~1 to about 14.6 atm ( lOOto350 pslg). In fact, it is singular advantage of the present inventlon that it aliows stable operation at lower pressu~es than have heretorore been possible in so~called ; "continuous" reforming systems (i.e., reforming for periods of_about 5~2 to about 70 cubic meters of charge per Kg of '0 catalyst without regeneration). In other words, the catalyst of the present invention allows the operation of a continuous reforming system to be ccnducted at lower pressure for about the same or better catalyst life as has been heretofore realized witb conventional catalysts at higher pressures '5 : . .
108()~ 9 The temperature required for reforming is generally low~r than that required for a similar reforming operation slng a high quality catalyst of the prior art. This signi-flcant and desirable feature of the present invention is a S conse;quence of the selectivity of the catalyst of the present invention for the octane-upgrading reactions that are prefer-ably induced in a typical reforming operation.
The initial selection of the temperature is made primarily as a function of the desired octane of the product 0 reformate. Ordinarily, the temperature is slowly increased d~ring the run to compensate for the inevitable deactivation that occurs to provide a constant octane product. Therefore,it is an advantage of the catalyst of the present invention that the rate of temperature increase required to maintain a constant octane product is substantially less than for reforming catalyst manufactured in exactly the same manner except for the exclu-sion of the -t~n and/or rhenium component. Moreover, when sing the catalyst of the present invention~ the C5+ yield loss for a given temperature increase is substantially lower 0 than for reforming catalysts of the prior art. In addition, hydrogen production is substantially higher.
; The reforming embodiment of the present invention utilizes sufficient hydrogen to provide from about 1 to about .
20 moles of hydrogen per mole of hydrocarbon entering the
The final catalyst generally is dried at a tempera-ture of about 93C (200F) to about 316C (600F) for a period of from about 2 to about 24 hours or more, and finally calcined at a temperature of about 371C (700F) to about 593C (1100F) in an air atmosphere for a period of about 0.5 to about 10 hours to convert the metallic components substantially to the ~xide form. In the case where a halogen component is utilized in the catalyst, best results are generally obtained when the halogen content of the catalyst -` is adjusted during the calcination step by including a hal-ogen or a halogen-containing compound in the air atmosphere utiiized. In particular, when the halogen component of the catalyst is chlorine, it is preferred to use a mole ratio of 10~ 8~
H20 to HCl o~ about 20:1 to about 100:1 during at least a portion of the calcination step in order to adjust the final chlorine content of the catalyst to a range of about 0.5 to about 1.2 wt %.
It is preferred that the resultant calcined catalytic composite be subjected to a reduction step prior to its use in the conversion of hydrocarbons. This step is designed to insure a uniform and finely divided dis-persion of the metallic components throughout the carrier material. Preferably, substantially pure and dry hydrogen containing less than 20 vol ppm H20 is used as the reducing agent. The reducing agent is contacted with the calcined catalyst at a temperature of about 427C (800F) to about 649C (1200F) and for a period of time of about 0.5 to 10 hours or more, effective to substantially reduce the metallic components to their elemental state. This reduction treatment may be performed in situ as part of a start-up sequence if precautions are taken to pre-dry the plant to a substantially water-free state and if substantially water-free hydrogen is used.
The resulting reduced catalytic composite may, in some cases, be beneficially subjected to a presulfiding operation designed to lncorporate in the catalytic composite from about 0.05 to about 0.5 wt % sulfur calculated on an elemental basis. Preferably, this presulfiding treatment ' 108~)~89 takes place in the presence of hydrogen and a suitable sulfur-containing compound such as hydrogen sulfide, lower molecular weight mercaptans, or organic sulfides. Thls procedure com-prises treating the reduced catalyst with a sulfiding gas, such as a mixture of hydrogen and hydrogen sulfide having about 10 moles of hydrogen per mole of hydrogen sulfide, at conditions which effect the desired incorporation of sulfur, generally including a temperature ranging from about 10C (50F) up to about 593C (1100 F). It is generally a good practice to perform this presulfiding step under sub-stantially water-free conditions.
According to the present invention, a hydrocarbon charge stock and hydrogen are contacted with a catalyst of the type described above in a hydrocarbon conversion zone.
Th~s contacting may be accomplished by using the catalyst in a fixed bed system, a moving bed system, a fluidized bed system, or in a batch type operation however, in view of the danger of attrition losses of the valuable catalyst, and of well known operational advantages, it is preferred to use a fixed bed system. In this system, a hydrogen-- rich gas and the charge stock are preheated to the desired reaction temperature and passed into a conversion zone con-taining a fixed bed of the aforementioned catalyst. The conversion zone may comprise one or more separate reactors with suitable means therebetween to insure that the desired ~080~i8~
conversion temperature is maintained at the entrance to each reactor. The reactants may be contacted with the catalyst bed in either upward, downward, or radial flow fashion with the latter being preferred. The reactants may be in the liquid phase, a mixed liquid-vapor phase, or a vapor phase when they contact the catalyst, with best results obtained in the vapor phase.
When the catalyst of the present invention is used in a reforming operation, the reforming system will comprise one or more separate reactors containing fixed beds of catalyst with suitable heating means therebetween to compensate for the endothermic nature of the reaction that takes place in each catalyst bed.` The hydrocarbon feed to the reforming system will comprise hydrocarbon fractions containing naph-lS thenes and paraffins boiling within the gasoline rangeD The preferred charge stocks are those consisting essentially of naphthenes and paraffins, although aromatics may also be present. This preferred class includes straight run gaso-lines, natural gasolines, synthetic gasolines, as well as thermally or catalytically cracXed gasolines or higher boiling fractions thereof, or mixtures of these. The gasoline charge stock may be a full boiling gasoline having an initial boiling point of from about 10 C (50 F) to about 66C (150~F) and an end boiling point within the range of from about 163C (325F) to about 219C (425 F), or may be a selected fraction thereof which generally will be a higher boiling fraction commonly .~ .
10~ 89 re~erred to as a heavy naphtha -- ror example, a naphtha boiling in the rar.ge of C7 ~o 204C (400F). In some cases, lt is also advantageous to charge pure hydrocarbons or mixtures o~ hydrocarbons that have been extracted rrom hydrocarbon distillates~ for example, straight chain paraffins, which ar~ tc be converted tO aromatics~ It is preferred that these charge stocks be treated by conventional catalytic pretreatment methods such as hydrorefining~ hydrotreating, or h~drcdesulfurizatlo-. to remcve s~bstantially a~l sulfurous, 0 - nitrogenous and water-ylelding conta~inants and to saturate any olefins present.
When catalyst of the present invention is used to pro.~ote isomerization~ the charge stock can be~ for example, a paraffiric stocX rich in C4 to C8 r.ormal paraffins, n-butar.e-rich stcck, n-hexane-rich stock or a mixture of xylene isomers as well as alkylaromatics and naphthenes. In hydrocracking embodiments the charge stock wlll ke typically a gas oil or heavy cracked cycle oil.
Likewise, pure hydrocarbons or substantially pure hydro-!0 carbor.s can be converted to more valuable products by using the catalyst of the present invention in any of the hydro-carkon conversion processes kncwn to the art that use a do31-function catalyst.
In the case or reforming it is sometlmes preferred that the novel catal,~tic coclposite be utlllzed in a sub-stantially water-rree environ.T,ent To achleve thls condition - '.
108~)689 n the reforming zone requires control of the water content of the charge stock and of the hydrogen stream charged to the conversion zone. Best results are cbtained when the total amount of water (expressed as weight of equivalent water ln the charge stock) enter ng the conversion zone rrom any source is less than 50 and preferably less than 20 wt ppm~ The charge stock can be dried by using any con-ventional solid adsorbent selective for water, for instance, sodium or calcium crystalline aluminosilicates, silica gel, actlvated alumina~ molecular sieves, anhydrous calcium sulfate, -high surface area sodium and the like adsorbents. Similarly, the water content of the charge stock may be adjusted by suitable stripping operations in a fractionation column or like device. And ln some cases, a comblnation of adsorbent drying and dlstillation drying may be used advantageously to effect almost complete removal of water from the chaxge stockO Pref-erably, the charge stock is drled to less than 20 ppm of water, In general, it is preferred to dry the hydrogen stream entering the hydrocarbon conversion zone to lO vol ppm of water or less. This can be conveniently accompllshed by contacting the hydroger. stream with a sultable desiccant such as those mentioned above.
In the reforming embodiment~ an effluent stream is wlthdrawn from the reforming zone and passed through cooling means to a separation zone, typically maintained at about . -: .
~08V~89 -~C (25F) to 66C (150F), wherein hydrogen-rich gas is separated from high octane liquid product, commonly called unstabilized reformate. Preferably, at least a portion of this hydrogen-rich gas is withdrawn from the separating zone and passed over an adsorbent selective for water. The resultant substantially water-free hydrogen stream is then recycled to the reforming zoneO The liquid phase from the separating zone is then withdrawn and treated in a fractionating system to adjust the butane concentration and volatility of the resulting reformate.
The conditions utilized in the numerous hydro-carbon conversion embodimentsofthe present invention are those customarily used in the art for the particular reac-tion or combination of reactions to be effected~ For instance, alkylaromatic and paraffin isomerization conditions include:
a temperature of about 0C (32F) to about 538C (1000F) and preferably about 24C (75F) to about 316 C (600F); a pressure of atmospheric to about lO0 atmospheres; a hydrogen to hydrocarbon mole ratio of about 0.5:1 to about 20:1, and a liquid hourly space velocity (LHSV) (calculated on the - basis of equivalent liquid volume per hour of the charge stock contacted with the catalyst divlded by the volume of catalyst) of about 0O2 to 10~ Dehydrogenation conditions include: a temperature of about 371C (700F) to about 677C (1250F), a pressure of about 0.1 to about lO atmos-pheres, an LHSV of about l to about 40, and a hydrogen-to-~08~f~89 hydrocarbon mole ratio of abo_t 1.1 to about 20:1. Hydro-cracki~.g conditions include: a pressure of about 35 atm (500 pSlg) to about 205 atm (3000 pslg), a temperature of abo~t 204C (4000F) to about 482C (900F); an LHSV of about S 0.1 to aboat lO~and hydrogen circulation rates of about i,~ to 17~0 standard cubic meters per cubic meter (cm/cm) of liquld charge (corresponding to from about 1000 to 10,000 SCF per barrel of charge).
In the reforming embodiment of the present invention the pressure utilized is selected from the range of about atmosphesic to abo~t 69 atm (1000 psig), with the preferred pressure range belng about 7.8atm (~ psig) to about 41.8 atm (600 psig). Particularly gocd resul~s are obtained at low pressure; namelyc a pressure of from about 6~1 to about 14.6 atm ( lOOto350 pslg). In fact, it is singular advantage of the present inventlon that it aliows stable operation at lower pressu~es than have heretorore been possible in so~called ; "continuous" reforming systems (i.e., reforming for periods of_about 5~2 to about 70 cubic meters of charge per Kg of '0 catalyst without regeneration). In other words, the catalyst of the present invention allows the operation of a continuous reforming system to be ccnducted at lower pressure for about the same or better catalyst life as has been heretofore realized witb conventional catalysts at higher pressures '5 : . .
108()~ 9 The temperature required for reforming is generally low~r than that required for a similar reforming operation slng a high quality catalyst of the prior art. This signi-flcant and desirable feature of the present invention is a S conse;quence of the selectivity of the catalyst of the present invention for the octane-upgrading reactions that are prefer-ably induced in a typical reforming operation.
The initial selection of the temperature is made primarily as a function of the desired octane of the product 0 reformate. Ordinarily, the temperature is slowly increased d~ring the run to compensate for the inevitable deactivation that occurs to provide a constant octane product. Therefore,it is an advantage of the catalyst of the present invention that the rate of temperature increase required to maintain a constant octane product is substantially less than for reforming catalyst manufactured in exactly the same manner except for the exclu-sion of the -t~n and/or rhenium component. Moreover, when sing the catalyst of the present invention~ the C5+ yield loss for a given temperature increase is substantially lower 0 than for reforming catalysts of the prior art. In addition, hydrogen production is substantially higher.
; The reforming embodiment of the present invention utilizes sufficient hydrogen to provide from about 1 to about .
20 moles of hydrogen per mole of hydrocarbon entering the
5- re~orming zone, with excellent results being obtained when - from about 5 to about 10 moles of hydrogen are supplied per -. ~ .
108~)689 mole of hydrocarbon The LHSV used is within the range of about 0~1 to about 10, with a value in the range of about 1 to about 5 being preferred. In fact, it is a further advantage of the present invention that it allows operations to be conducted at higher LHSV than normally can be achieved in a stable, continuous reforming process with a high quality reforming catalyst of the prior art. This is of immense economic significance because it allows a continuous reforming process to operate at increased throughput with the same catalyst inventory.
The following examples are given-to illustrate further the preparation of the catalytic composite of the present invention and the use thereof in the conversion of hydrocarbons. It is understood that the examples are given for the sole purpose of illustration and are not to be con-sidered to limit the generally broad scope and spirit of the appended claimsO
EXAMPLE I
- This example demonstrates a particularly good method of preparing the preferred catalytic composite of - the present invention.
An alumina carrier material comprising 1.6 mm - (1/16 inch) spheres was prepared by: forming an aluminum hydroxyl chloride sol by dissolving substantially pure aluminum pellets in a hydrochloric acid solution, adding hexamethyl-- enetetramine to the resulting sol, gelling the resulting `:
10~
solution by dropping it into an oil bath to form spherical particles of an aluminum hydrogel, aging and washing the resulting particles and finally drying and calcining the aged and washed particles to fo~m spherical particles of gamma-alumina containing about 0.3 wt % combined chloride.
Additional details as to this method of preparing the pre-ferred carrier material are given in the teachings of U. S.
Patent No. 2,620, 314.
An aqueous solution containing chloroplatinic acid, perrhenic acid, hydrogen chloride and stannic chloride was then prepared. The solution was used to impregnate the gamma-alumina particles in amounts which produced a final composite containing 0.1 wt % Re, 0.12 wt % Sn and 0.2 wt % Pt. The impregnated spheres were then dried at a temperature of about 149C (300F) for about an hour and thereafter calcined in an air atmosphere at a temperature of about 496C (925F) for about 1 hour. The calcined spheres were then contacted with an air stream containing H2O and HCl in a mole ratio of about 40:1 for about 4 hours at 524C (975F) to adjust the halogen content of the catalyst partioles.
The resulting catalyst particles were analyzed and found to contain, on an elemental basis, about 0.2 wt %
platinum, about 0.12 wt % tin, about 0.1 wt % rhenium and about 0.85 wt % chloride.
EXAMPLE II
A portion of the spherical particles produced by the method described in Example I are loaded into a scale ;~ .
lOt3V~
model of a continuous, fixed-bed reforming plant of conven-tional design. In this plant a heavy Kuwait naphtha and hydrogen are continuously contacted at the following condi-tions: an LHSV of 1.5, a pressure of 7.8 atm (100 psig), a hydrogen-to-hydrocarbon mole ratio of lo l,and a tempera-ture sufficient to continuously produce a C5+ reformate of 102 F-l clear. These are exceptionally severe conditions.
The heavy Kuwait naphtha has a specific gravity of 0~7374 (15.6C/1506C) (API gravity at 60F of 60D4)~ an initial boiling point of 84C (184F), a 50%-distilled boiling point of 125C (256F), and an end boiling point of 182C (360F). In addition, it contains about 8 liqO vol %
aromatics, 71 liq; vol % paraffins, 21 liq vol % naphthenes, 0.5 wt ppm sulfur, and 5 to 9 wt ppm water. The F-l clear octane number of the raw stock is 40Ø .
The fixed bed reforming plant is made up of a catalyst-containing reactor, a hydrogen separation zone, a debutanizer column, and suitable heating, pumping, cooling, and controlling means. In this plant, a hydrogen recycle stream and the charge stock are commingled and heated to the desired temperature~ The resultant mixture is then passed downwardly through a reactor containing the catalyst as a fixed bed. An effluent stream is then withdrawn from the bottom of the reactor, cooled to about 13C (55F) and - 25 passed to a separating zone wherein a hydrogen-rich gaseous 108()~
phase separates from a liquid hydrocarbon phase. A portion of the gaseous phase is passed through a high surface area sodium scrubber and the resulting sulfur-free hydrogen stream is recycled to the reactor in order to supply hydrogen thereto, and the excess hydrogen over that needed to maintain plant pressure is recovered as excess separator gas. The liquid hydrocarbon phase from the hydrogen separating zone is with-drawn therefrom and passed to a debutanizer column of con-ventional design wherein light ends are taken overhead as debutanizer gas and a C5+ reformate stream is recovered as bottoms.
The test run is continued for a catalyst life of about 7 cubic meters of liquid charge per Kg of catalyst (20 barrels per pound) utilized, and it is determined that the activity, selectivity, and stability of the subject catalyst aré vastly superior to conventional commercial reforming catalysts utilized in a similar test. More speci-fically, the results obtained using the catalyst of the invention are superior to the platinum metal-containins cat-alyst of the prior art in respect of hydrogen production,C5+ yield at a given octane, average rate of temperature increase necessary to maintain octane, and C5+ yield-decline rate.
.
.
108~)689 mole of hydrocarbon The LHSV used is within the range of about 0~1 to about 10, with a value in the range of about 1 to about 5 being preferred. In fact, it is a further advantage of the present invention that it allows operations to be conducted at higher LHSV than normally can be achieved in a stable, continuous reforming process with a high quality reforming catalyst of the prior art. This is of immense economic significance because it allows a continuous reforming process to operate at increased throughput with the same catalyst inventory.
The following examples are given-to illustrate further the preparation of the catalytic composite of the present invention and the use thereof in the conversion of hydrocarbons. It is understood that the examples are given for the sole purpose of illustration and are not to be con-sidered to limit the generally broad scope and spirit of the appended claimsO
EXAMPLE I
- This example demonstrates a particularly good method of preparing the preferred catalytic composite of - the present invention.
An alumina carrier material comprising 1.6 mm - (1/16 inch) spheres was prepared by: forming an aluminum hydroxyl chloride sol by dissolving substantially pure aluminum pellets in a hydrochloric acid solution, adding hexamethyl-- enetetramine to the resulting sol, gelling the resulting `:
10~
solution by dropping it into an oil bath to form spherical particles of an aluminum hydrogel, aging and washing the resulting particles and finally drying and calcining the aged and washed particles to fo~m spherical particles of gamma-alumina containing about 0.3 wt % combined chloride.
Additional details as to this method of preparing the pre-ferred carrier material are given in the teachings of U. S.
Patent No. 2,620, 314.
An aqueous solution containing chloroplatinic acid, perrhenic acid, hydrogen chloride and stannic chloride was then prepared. The solution was used to impregnate the gamma-alumina particles in amounts which produced a final composite containing 0.1 wt % Re, 0.12 wt % Sn and 0.2 wt % Pt. The impregnated spheres were then dried at a temperature of about 149C (300F) for about an hour and thereafter calcined in an air atmosphere at a temperature of about 496C (925F) for about 1 hour. The calcined spheres were then contacted with an air stream containing H2O and HCl in a mole ratio of about 40:1 for about 4 hours at 524C (975F) to adjust the halogen content of the catalyst partioles.
The resulting catalyst particles were analyzed and found to contain, on an elemental basis, about 0.2 wt %
platinum, about 0.12 wt % tin, about 0.1 wt % rhenium and about 0.85 wt % chloride.
EXAMPLE II
A portion of the spherical particles produced by the method described in Example I are loaded into a scale ;~ .
lOt3V~
model of a continuous, fixed-bed reforming plant of conven-tional design. In this plant a heavy Kuwait naphtha and hydrogen are continuously contacted at the following condi-tions: an LHSV of 1.5, a pressure of 7.8 atm (100 psig), a hydrogen-to-hydrocarbon mole ratio of lo l,and a tempera-ture sufficient to continuously produce a C5+ reformate of 102 F-l clear. These are exceptionally severe conditions.
The heavy Kuwait naphtha has a specific gravity of 0~7374 (15.6C/1506C) (API gravity at 60F of 60D4)~ an initial boiling point of 84C (184F), a 50%-distilled boiling point of 125C (256F), and an end boiling point of 182C (360F). In addition, it contains about 8 liqO vol %
aromatics, 71 liq; vol % paraffins, 21 liq vol % naphthenes, 0.5 wt ppm sulfur, and 5 to 9 wt ppm water. The F-l clear octane number of the raw stock is 40Ø .
The fixed bed reforming plant is made up of a catalyst-containing reactor, a hydrogen separation zone, a debutanizer column, and suitable heating, pumping, cooling, and controlling means. In this plant, a hydrogen recycle stream and the charge stock are commingled and heated to the desired temperature~ The resultant mixture is then passed downwardly through a reactor containing the catalyst as a fixed bed. An effluent stream is then withdrawn from the bottom of the reactor, cooled to about 13C (55F) and - 25 passed to a separating zone wherein a hydrogen-rich gaseous 108()~
phase separates from a liquid hydrocarbon phase. A portion of the gaseous phase is passed through a high surface area sodium scrubber and the resulting sulfur-free hydrogen stream is recycled to the reactor in order to supply hydrogen thereto, and the excess hydrogen over that needed to maintain plant pressure is recovered as excess separator gas. The liquid hydrocarbon phase from the hydrogen separating zone is with-drawn therefrom and passed to a debutanizer column of con-ventional design wherein light ends are taken overhead as debutanizer gas and a C5+ reformate stream is recovered as bottoms.
The test run is continued for a catalyst life of about 7 cubic meters of liquid charge per Kg of catalyst (20 barrels per pound) utilized, and it is determined that the activity, selectivity, and stability of the subject catalyst aré vastly superior to conventional commercial reforming catalysts utilized in a similar test. More speci-fically, the results obtained using the catalyst of the invention are superior to the platinum metal-containins cat-alyst of the prior art in respect of hydrogen production,C5+ yield at a given octane, average rate of temperature increase necessary to maintain octane, and C5+ yield-decline rate.
.
.
Claims (31)
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A catalytic composite comprising a combination of about 0.01 to about 1.0 wt. % of a platinum group metal, about 0.01 to about 1.0 wt. % of rhenium, about 0.01 to about 5.0 wt.% of tin, and a porous carrier material, the aforesaid percentages being on an elemental basis, the atomic ratio of platinum group to tin being about 0.1:1 to about 3:1 and the atomic ratio of platinum group metal to rhenium being about 0.05:1 to about 2.75:1.
2 A catalytic composite as defined in claim 1, wherein the platinum group component comprises platinum or a compound of platinum.
3. A catalytic composite as defined in claim 1, wherein the porous carrier material comprises a refractory inorganic oxide.
4. A catalytic composite as defined in claim 3, wherein the refractory inorganic oxide is alumina.
5. A catalytic composite comprising a combination of about 0.01 to about 1.0 wt. % of platinum, about 0.01 to about 1.0 wt. % of rhenium, about 0.01 to about 5.0 wt.% of tin, about 0.1 to about 1.5 wt. % of halogen, and an alumina carrier material, the aforesaid percentages being on an elemental basis, the atomic ratio of platinum to tin being about 0.5:1 to about 1.5:1 and the atomic ratio of platinum to rhenium being about 0.25:1 to about 2.0:1.
6. A catalytic composite as defined in claim 5, wherein the halogen component comprises chlorine or compounds of chlorine.
7. A catalytic composite as defined in claim 6 wherein the composite contains from about 0.5 to 1.2 wt. % chlorine on an elemental basis.
8. A catalytic composite as defined in claim 1, wherein the composite contains from about 0.05 to about 0.5 wt %
sulfur on an elemental basis.
sulfur on an elemental basis.
9. A catalytic composite as defined in claim 1, 5 or 8, wherein the composite is treated with hydrogen at a temper-ature of from about 427°C. to about 649°C. whereby to reduce the metallic components to their elemental state.
10. A process for the conversion of a hydrocarbon, which comprises subjecting said hydrocarbon to contact at hydrocarbon conversion conditions with a catalytic composite comprising a combination of about 0.01 to about 1.0 wt % of a platinum group metal, about 0.01 to about 1.0 wt % of rhenium, about 0.01 to about 5.0 wt % of tin, and a porous carrier material, the afore-said percentages being on an elemental basis, the atomic ratio of platinum group to tin being about 0.1:1 to about 3:1 and the atomic ratio of platinum group metal to rhenium being about 0.05:1 to about 2.75:1.
11. Process according to claim 10, wherein the porous carrier material comprises a refractory inorganic oxide.
12. Process according to claim 11, wherein the refractory inorganic oxide is alumina.
13. Process according to claim 10, wherein the hydrocarbon is subjected to contact with the catalytic composite in the presence of hydrogen.
14. Process according to claim 10, 11 or 12, wherein the platinum group component comprises platinum or a compound of platinum.
15. A process for the conversion of a hydrocarbon, which comprises subjecting said hydrocarbon to contact at hydrocarbon conversion conditions with a catalytic composite comprising a combination of about 0.01 to about 1.0 wt % of platinum, about 0,01 to about 1.0 wt % of rhenium, about 0.01 to about 5.0 wt %
of tin, about 0.1 to about 1.5 wt % halogen, and an alumina carrier material, the aforesaid percentages being on an elemental basis, the atomic ratio of platinum to tin being about 0.5:1 to about 1.5:1 and the atomic ratio of platinum to rhenium being about 0.25:1 to about 2.0:1.
of tin, about 0.1 to about 1.5 wt % halogen, and an alumina carrier material, the aforesaid percentages being on an elemental basis, the atomic ratio of platinum to tin being about 0.5:1 to about 1.5:1 and the atomic ratio of platinum to rhenium being about 0.25:1 to about 2.0:1.
16. Process according to claim15, wherein the halogen component is chlorine or a compound of chlorine.
17. Process according to claim 15, wherein a gasoline fraction is subjected to contact with the catalytic composite at gasoline reforming conditions, and a reformed gasoline is recovered as product of the process.
18. Process according to claim 17, wherein the gasoline fraction is reformed at a temperature of about 427° to 593°C.
a pressure of about atmospheric to about 69 atmospheres, a liquid hourly space velocity of about 0.1 to about 10, and a mole ratio of hydrogen to hydrocarbon of about 1 to 20.
a pressure of about atmospheric to about 69 atmospheres, a liquid hourly space velocity of about 0.1 to about 10, and a mole ratio of hydrogen to hydrocarbon of about 1 to 20.
19. Process according to claim 18, wherein the gasoline fraction is reformed at a pressure of about 7.8 to about 41.8 atmospheres.
20. Process according to claim 17, 18 or 19, wherein the gasoline fraction is reformed in a substantially water-free environment.
21. Process according to claim 10, 15 or 17, wherein the catalytic composite also contains a sulfur component in a concen-tration of about 0.05 to 0.5 wt. % on an elemental basis.
22. Process according to claim 10, 13 or 15, wherein an isomerizable hydrocarbon selected from the alkylaromatic and paraffin hydrocarbons is subjected to contact with the catalytic composite at a temperature of about O° to about 538°C, a pressure of about 1 to 100 atmospheres, an LHSV of about 0.2 to 10, and a mole ratio of hydrogen to hydrocarbon of out 0.5:1 to 20:1, and LBSH of about 0.2 to 10 and an isomerized hydro-carbon is recovered from the process.
23. Process according to claim 10, 13 or 15, wherein a charge stock selected from the gas oils and heavy cracked cycle oils is subjected to contact with the catalytic composite at a temperature of about 204° to 482°C, a pressure of about 35 to 205 atms., an LHSV of about 0.1 to 10 and a hydrogen circulation rate within the range of about 178 to 1780 cubic meters per cubic meter of charge, and a hydro-cracked product is recovered from the process.
24. Process according to claim 10, 13 or 15, wherein a dehydrogenatable hydrocarbon is subjected to contact with the catalytic composite at a temperature of about 371 to 677°C, a pressure of about 0.1 to 10 atm. an LHSV of about 1 to 40, and a hydrogen to hydrocarbon mole ratio or about 1:1 to about 20:1, and a dehydrogenated hydrocarbon is recovered from the process.
25. A catalytic composition of matter comprising 0.01 to 1 weight percent of a platinum group component, 0.01 to 1 weight percent rhenium, 0.01 to 5 weight percent of a tin component and 0.1 to 10 weight percent of a halogen in association with a porous alumina carrier.
26. A hydroforming catalyst comprising a porous, refractory, inorganic oxide support having a specific surface greater than 15 m2/g, a specific pore volume greater than 0.1 cc/g, and acidic sites, and having on said support 0.01% to 1% of at least one metal of the platinum group, and .01% to 5% of at least one metal of the group consisting of lead and tin; and 0.01% to 1% of rhenium, where said percentages refer to the total weight of the catalyst.
27. A catalyst according to claim 26, further comprising on said support chlorine in combined form in an amount, calculated as all element, of between 0.1% and 10%
referred to the total weight of the catalyst.
referred to the total weight of the catalyst.
28. A process for activating a catalytic composition including a porous alumina carrier, a platinum group component, a rhenium component and a tin component, comprising: reacting the catalytic com-position with an activating gas including oxygen and a halogenating component at a temperature within the range from about 500°F to about 1100°F for at least about 0.5 hour.
29. A process in accordance with claim 28 wherein the catalytic composition, prior to the reacting step, includes a halogen.
30. In a reforming process comprising passing naphtha feedstock in series to a plurality of reaction zones in each of which reaction zones the naphtha, hydrogen and a reforming catalyst are contacted under reforming conditions to produce high octane gasoline; periodically isolating one of said reaction zones from other reaction zones and discontinuing reforming in said isolated reaction zone without the dis-continuing of reforming in other reaction zones; regenerating said catalyst in said isolated reaction zone, then placing said isolated reaction zone back into the reforming operation;
the improvement which comprises: contacting said naphtha in the presence of hydrogen at reforming conditions including a pressure from 20 to 300 psig. a hydrogen-to-hydrocarbon mole ratio of less than about 10, a lower hydrogen-to-hydro-carbon mole ratio being used at the lower pressures, and a liquid hourly space velocity of about 0.5 to 10, with a catalyst including alumina, 0.01 to 1 weight percent platinum, 0.01 to 1 weight percent rhenium, 0Ø1. to 5 weight percent tin, and 0.1 to 10 weight percent halogen to form a high octane gasoline product.
the improvement which comprises: contacting said naphtha in the presence of hydrogen at reforming conditions including a pressure from 20 to 300 psig. a hydrogen-to-hydrocarbon mole ratio of less than about 10, a lower hydrogen-to-hydro-carbon mole ratio being used at the lower pressures, and a liquid hourly space velocity of about 0.5 to 10, with a catalyst including alumina, 0.01 to 1 weight percent platinum, 0.01 to 1 weight percent rhenium, 0Ø1. to 5 weight percent tin, and 0.1 to 10 weight percent halogen to form a high octane gasoline product.
31. A process in accordance with claim 28, wherein the catalytic composition includes 0.01 to 1 weight percent rhenium.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA103,565A CA1080689A (en) | 1971-01-25 | 1971-01-25 | Hydrocarbon conversion process and catalyst therefor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA103,565A CA1080689A (en) | 1971-01-25 | 1971-01-25 | Hydrocarbon conversion process and catalyst therefor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1080689A true CA1080689A (en) | 1980-07-01 |
Family
ID=4088562
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA103,565A Expired CA1080689A (en) | 1971-01-25 | 1971-01-25 | Hydrocarbon conversion process and catalyst therefor |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1080689A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2631282A1 (en) | 2012-02-24 | 2013-08-28 | Repsol, S.A. | Process for producing middle distillates |
| CN115232643A (en) * | 2022-09-22 | 2022-10-25 | 潍坊弘润石化科技有限公司 | Hydrocracking method |
-
1971
- 1971-01-25 CA CA103,565A patent/CA1080689A/en not_active Expired
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2631282A1 (en) | 2012-02-24 | 2013-08-28 | Repsol, S.A. | Process for producing middle distillates |
| CN115232643A (en) * | 2022-09-22 | 2022-10-25 | 潍坊弘润石化科技有限公司 | Hydrocracking method |
| CN115232643B (en) * | 2022-09-22 | 2022-11-25 | 潍坊弘润石化科技有限公司 | Hydrocracking method |
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