MXPA97006838A - Composite catalytic conversion of multimetal bifunctional selective hydrocarbon and process for the use of the - Google Patents

Abstract

A new catalyst and the use of it in a hydrocarbon conversion process are presented. The catalyst includes refractory inorganic oxide, a metal of the platinum group, a metal of the IVA Group (IUPAC 14) and europium in a specified ratio. The use of this catalyst in the conversion of hydrocarbons, especially in the conversion, results in a rather improved selectivity for the desired product of gasoline or aromatic substances.

Description

"COMPOSITE CATALYTIC CONVERSION OF MULTIMETAL HYDROCARBON BIFUNCIONAL SELECTIVE AND PROCESS FOR THE USE OF THE SAME "BACKGROUND The tea of the present invention is a new catalytic compound with double function, characterized by a combination of three or more metals in specific concentrations in the finished catalyst and its use in the conversion of hydrocarbons. Catalysts that have both a hydrogenation-dehydrogenation function and a disintegration function are widely used in many applications, particularly in the petroleum industry and the petrochemical industry, to accelerate a broad spectrum of hydrocarbon conversion reactions. it is generally related to a porous oxide, adsorptive and refractory acid-action material that is generally used as a carrier or carrier of a heavy metal component, such as Group VIII metals (IUPAC 8-10) contribute mainly to the function of hydrogenation-dehydrogenation. Binomials or in elemental form can influence one or both of the disintegration and hydrogenation-dehydrogenation functions. In another aspect, the present invention includes improved processes arising from the use of the new catalyst. These double function catalysts are used to accelerate a wide variety of hydrocarbon conversion reactions, such as dehydrogenation, hydrogenation, hydrodisintegration, hydrogenolysis, isomerization, desulphurization, cyclization, alkylation, polymerization, disintegration and hydroizomerization. In one specific aspect, an improved conversion process uses the subject catalyst to increase the selectivity for gasoline products and aromatic substances. The catalytic conversion involves a certain number of 10 competitive processes or reaction sequences. These include the dehydrogenation of cyclohexanes in aromatic substances, the dehydroisomerization of alkylcyclopentanes in aromatic substances, the dehydrocyclization of an acyclic hydrocarbon in aromatic substances, the hydrodisintegration of paraffins in light products that are extracted by boiling out of the range of gasoline, the dealkylation of alkylbenzenes and the isomerization of paraffins. Some of the reactions that occur during the conversion, such as the hydrodisintegration that produces light paraffin gases, have a detrimental effect on the performance of products boiling in the range of gasoline. Therefore, the improvements in the catalytic conversion process are focused on the improvement of these reactions that achieve a greater performance of the fraction of gasoline in an index of octane given.

It is of paramount importance that a double-function catalyst has the ability to both perform its specified functions efficiently initially and perform them successfully for extended periods of time. The parameters used in the art to measure how well a particular catalyst performs its proposed functions in a particular hydrocarbon reaction environment are activity, selectivity and stability. In a conversion environment, these parameters are defined as follows: (1) The activity is a measure of the catalyst's ability to convert hydrocarbon reactants into products at a designated severity level, where the level of severity represents a combination of conditions of the reaction: temperature, pressure, contact time and partial pressure of hydrogen. The activity is usually referred to as the octane number of the pentanes and the heavier product stream ("C5 +") of a given feed at a given severity level, or to the Inverse, as the temperature required to achieve a given octane number. (2) Selectivity refers to the percentage yield of petrochemical aromatics or the C5 + gasoline product of a given feed at a level of activity in particular. (3) Stability refers to the rate of change of activity or selectivity per time unit or processed feed. Activity stability is usually measured as the rate of change of operating temperature per unit time or feed to achieve an octane of a given C5 + product, where a lower rate of change in temperature corresponds to better stability of the activity, since the units of the catalytic conversion usually operate at the octane of the relatively constant product. The stability of the selectivity is measured as the speed in the decrease of the yield of the C5 + product or the aromatic substances per unit of time or of feeding. 15 The development of programs to improve the performance of conversion catalysts through the reformulation of gasoline is being encouraged, followed by the widespread removal of lead antiknock additives, in order to reduce harmful emissions from vehicles. The processes to improve gasoline, such as catalytic conversion, must operate with greater efficiency and greater flexibility in order to meet these exchange requirements. The selectivity of the catalysts is becoming more important in adapting the components of gasoline to these needs and at the same time avoid losses for lower value products. Therefore, the main problem faced by workers in this area of the art is to develop more selective catalysts while maintaining effective activity and stability of the catalyst. The technique shows a variety of multimetal catalysts for the catalytic conversion of naphtha feed supplies. Most of these comprise a selection of metals from the group of platinum, rhenium and metals from ß 10 Group IV (IUPAC 14). United States Patent US-A-3915845 presents the conversion of hydrocarbons with a catalyst consisting of a metal of the platinum group, a metal of the Group IVA, halogen and lanthanide in an atomic relationship with the metal of the platinum group from 0.1 to 1.25. The preferred lanthanides are lanthanum, cerium and especially neodymium. United States Patent US-A-4039477 discloses a catalyst for the catalytic hydrotreatment of hydrocarbons comprising a refractory metal oxide, a metal from the group of platinum, tin and at least one metal of the following: yttrium, thorium, uranium, praseodymium, cerium, lanthanum, neodymium, samarium, dysprosium and gadolinium with favorable results observed in relatively low relations of these latter metals with the platinum. The Patent of US-A-5254518 shows a catalyst containing a noble metal of Group VIII, an oxide of Group IVB # and amorphous silica-alumina in which a rare earth oxide, preferably Nd or Y, is deposited. SUMMARY OF THE INVENTION One of the objects of the present invention is to provide a new catalyst for the improved selectivity in the conversion of hydrocarbons. . An objective resulting from the invention is to provide a conversion process having an improved selectivity with respect to the yields of the • 10 gasoline or aromatic substances. The invention originates more specifically from the discovery that a catalyst containing platinum, tin and europium in halogenated alumina shows a favorable relation of aromatization with disintegration in a hydrocarbon conversion reaction. An extended embodiment of the present invention is a catalyst that includes a refractory inorganic oxide, a Group IV metal (IUPAC 14), a metal of the platinum group and a metal of the lanthanide series. The The atomic ratio of the lanthanide metal to the metal of the platinum group is preferably at least 1.3, more preferably 1.5 or greater and even more preferably 2 to 5. Optimally, the catalyst also preferably includes a halogen, especially the chlorine. In the embodiments Preferred, the refractory inorganic oxide is an alumina, the metal of the platinum group is the platinum and the metal of the IVA Group (IUPAC 14) is the tin; the metal of the platinum group is platinum and the metal of the lanthanide series is selected from at least one of the following: europium and ytterbium. A highly preferred catalyst includes tin, platinum and europium mainly in the form of EuO in an alumina support. In another aspect, the invention is a process for the conversion of a hydrocarbon feed supply using the present catalyst. Preferably, the hydrocarbon conversion is the catalytic conversion of a naphtha feedstock, using the catalyst of the invention to increase the yield of gasoline and / or aromatic substances. The conversion preferably includes dehydrocyclization to increase the yield of the aromatic substances. Optimally, the naphtha feed supply includes hydrocarbons in the C6-C8 range that produce one or more of the following: benzene, toluene and xylenes in a catalytic conversion unit. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 compares the disintegration and aromatization yields when processing a naphtha feed supply using catalysts of the invention and the prior art. Figure 2 compares the selectivity of the conversion for the prior art catalysts and the present invention when processing a naphtha feed supply. Figure 3 shows the yield of C5 + against aromatic substances for three Eu 5-containing catalysts compared to a reference catalyst which does not contain Eu. Figure 4 shows the relative activity and selectivity of the Eu-containing catalysts as a function of Eu content. DESCRIPTION OF THE PREFERRED EMBODIMENTS Therefore, an extensive embodiment of the present invention is a catalyst that includes a refractory inorganic oxide support, at least one metal of the Group IVA (IUPAC 14) of the Periodic Table [ Consult Cotton and Wilkinson, Advanced Inoraanic Chemistrv ("Inorganic Chemistry Advanced "), John Wiley &Sons (Fifth Edition, 1988)], a metal of the platinum group and a metal of the lanthanide series.The refractory support used in the present invention is usually a porous, adsorptive support. , with a high surface area, which has a surface area of 25 to 500 m2 / g. The porous carrier material must also be uniform in its composition and relatively refractory to the conditions used in the hydrocarbon conversion process. By the terms "uniform in your composition "indicates that the support should not have layers, should not have gradients of concentration of the species ^ m inherent in its composition and must be completely homogeneous in its composition. Therefore, if the support is a mixture of two or more refractory materials, the relative amounts of these materials will be constant and uniform across the entire support. The purpose is to include within the scope of the present invention carrier materials which have traditionally been used in double function hydrocarbon conversion catalysts, such as for example: (1) refractory inorganic oxides such as alumina, magnesia, titania, zirconia, chromia, zinc oxide, thoria, boria, silica-alumina, silica-magnesia, chromia-alumina, alumina-boria, silica-zirconia, etc.; (2) ceramics, porcelain, bauxite; 15 (3) silica or silica gel, silicon carbide, clays and silicates that are prepared synthetically or occur naturally, which may or may not be treated with acids, for example, attapulguite clay, diatomaceous earth, earth fullan, kaolin or diatomite; 20 (4) crystalline zeolitic aluminosilicates, such as for example X-zeolite, Y-zeolite, mordenite, β-zeolite, O-zeolite or L-zeolite, either in the form of hydrogen or preferably in non-acid form with one or more metals of alkali occupying the interchangeable cationic sites; 25 (5) non-zeolitic molecular sieves, such as for example aluminophosphates or silica-aluminophosphates; and (6) combinations of one or more materials from one or more of these groups. Preferably the refractory support includes one or more inorganic oxides, with alumina being the preferred refractory inorganic oxide for use in the present invention. Suitable alumina materials are crystalline aluminas shown as gamma-, eta- and theta-alumina, of which gamma- or eta-alumina provides the best results. He Preferred inorganic refractory oxide will have an apparent bulk density of 0.3 to 1.0 g / cc and surface area characteristics such that the average pore diameter is 20 to 300 angstroms, the pore volume is 0.1 to 1 cc / g and the surface area of 100 to 500 m2 / g. Considering that alumina is the preferred refractory inorganic oxide, a preferred alumina in particular is that which has been characterized in United States Patent US-A-3852190 and United States Patent US-A-4012313 as a product. secondary of a synthesis reaction of Ziegler's alcohol, as described in the United States Patent US-A-2892858. For simplification purposes, this alumina will be referred to as a "Ziegler alumina" from this moment. Ziegler alumina is currently available at Vista Chemical Company under the trademark "Catapal" or at Condea Chemie GmbH under the trademark "Pural". This material is a pseudobohemite of extremely high purity which, after calcination at high temperature, has been shown to produce a high purity gamma-alumina. The alumina powder can be molded into any desired shape or type of carrier material known to those skilled in the art, such as spheres, sticks, tablets, pills, tablets, granules, extruded products and similar forms by methods already? 10 known to those skilled in the art for the formation of catalyst materials. The preferred form of the current catalyst support is a sphere. The alumina spheres can be manufactured continuously with the well-known method of oil dripping Which includes: forming an alumina hydrosol by any of the techniques specified in the method and preferably reacting the aluminum metal with the hydrochloric acid; combine the resulting hydrosol with a suitable gelling agent and drop the resulting mixture in a oil bath maintained at elevated temperatures. The drops of the mixture remain in the oil bath until they settle and form hydrogel spheres. The spheres are then continuously removed from the oil bath and are usually subjected to specific ripening treatments and dried in oil and in an ammonia solution to subsequently improve its physical characteristics. The resulting matured and gelled particles are washed and subsequently dried at a relatively low temperature of 150 ° to 205 ° C and subjected to a calcination procedure at a temperature of 450 ° to 700 ° C for a period of 1 to 20 hours . This treatment performs the conversion of the alumina hydrogel to the corresponding crystalline gamma-alumina. United States Patent US-A-2620314 provides additional details and is incorporated herein by reference thereto. An alternative form of the carrier material is a cylindrical extruded product, preferably prepared by mixing the alumina powder with water and suitable peptizing agents such as for example HCl to form an extrudable paste. The amount of water added to form the paste is usually sufficient to provide a calcination loss (LOI) at 500 ° C of a mass percentage of 45 to 65, where a mass percentage value of 55 is preferred. Acid addition rate is usually sufficient to provide a mass percentage of 12 to 7 of the non-volatile alumina powder used in the mixture, where a mass percentage value of 3 to 4 is preferred. The resulting paste it is subjected to extrusion through a nozzle of adequate size to form the extruded particles. These particles are subsequently dried at a temperature of 260 ° to 427 ° C for a period of 0.1 to 5 hours to form the particles of the extruded product. It is preferred that the refractory inorganic oxide consists mainly of pure Ziegler alumina having an apparent bulk density of 0.6 to 1 g / cc and a surface area of 150 to 280 m2 / g (preferably 185 to 235 m2 / g, a a pore volume of 0.3 to 0.8 cc / g). A metal component of the IVA Group (IUPAC 14) is an essential ingredient of the catalyst of the present invention. Of the Group IVA metals (IUPAC 14), germanium and tin are preferred, and tin is especially preferred.

This component can be present as elemental metal, such as a chemical compound such as oxide, sulfur, halide, oxychloride, etc. , or as a physical or chemical combination with the porous carrier material and / or other components of the catalyst compound. Preferably, there is a portion of the Group IVA metal (IUPAC 14) in the finished catalyst in a state of oxidation higher than that of the elemental metal. The metal component of the IVA Group (IUPAC 14) is optimally used in an amount sufficient to result in a final catalytic compound containing a metal with a mass percentage of 0.01 to 5, calculated on an elemental basis, in which the best results are obtained at a metal level of 0.1 to 2 in mass percentage. The metal component of the IVA Group (IUPAC 14) can be incorporated into the catalyst by any suitable method to achieve a homogeneous dispersion, such as for example coprecipitation with the porous carrier material, exchange of ions with the carrier material or impregnation of the carrier material at any stage of the preparation. A method for the incorporation of the Group IVA metal component (IUPAC 14) into the catalyst compound involves the use of a soluble and unfolding compound of a Group IVA metal (IUPAC 14) to impregnate and disperse the metal through the material porous carrier. The metal component of the IVA Group (IUPAC 14) can be impregnated either before, in simultaneously with, or after, the other components are added to the carrier material. Therefore, the metal component of the IVA Group (IUPAC 14) can be added to the carrier material by mixing the latter with an aqueous solution of a suitable metal salt or a soluble compound such as for example the stannous bromide, stannous chloride, stannic chloride, stannic chloride pentahydrate; or germanium oxide, germanium tetraethoxide, germanium tetrachloride; or lead nitrate, lead acetate, lead chlorate and similar compounds. In particular, it is preferred to use the compounds of the Group IVA metal chloride (IUPAC 14), such as for example stannic chloride, germanium tetrachloride or lead chlorate, since it facilitates the incorporation of both the metallic component and at least a minor amount of the preferred halogen in one step. To the When combined with the hydrogen chloride during the peptization step of the preferred preferred alumina, which was described above, a homogeneous dispersion of the Group IVA metal component (IUPAC 14) according to the present invention is obtained. In an alternative embodiment, the organic metal compounds such as, for example, trimethyltin chloride and dimethyltin dichloride are incorporated into the catalyst during the peptization of the inorganic oxide binder, and more preferably during the peptization of the alumina. with hydrogen chloride or ßPlO nitric acid. Another essential ingredient of the catalyst is a metal component of the platinum group. This component includes platinum, palladium, ruthenium, rhodium, iridium, osmium or mixtures thereof, with the preferred platinum. The metal of the platinum group can exist within the final catalytic compound as a compound which can be for example an oxide, a sulfide, a halide, an oxyhalide, etc. , in chemical combination with one or more of the other ingredients of the compound or as an elemental metal. HE obtain better results when substantially all of this component is present in the elemental state and is dispersed homogeneously within the carrier material. This component can be present in the final catalyst compound in any amount that is catalytically effective; The metal of the platinum group usually comprises a mass percentage of 0.01 to 2 of the final catalyst compound, calculated on an elementary basis. Excellent results are obtained when the catalyst contains a mass percentage of 0.05 to 1 platinum. The metal component of the platinum group can be incorporated in the porous carrier material in any suitable manner, such as, for example, coprecipitation, ion exchange or impregnation. The preferred method for preparing the catalyst includes the use of a soluble and unfolding compound Wf 10 of the platinum group metal to impregnate the carrier material in a relatively uniform manner. For example, the component can be added to the support by mixing the latter with an aqueous solution of chloroplatinic or chlorohydric, or chloropalladic acid. Others Water-soluble compounds or complexes of the metals of the platinum group can be used in the impregnation solutions and include ammonium chloroplatinate, bromoplatinic acid, platinum trichloride, hydrated platinum tetrachloride, dichlorocarbonyl dichloride of platinum, dinitrodiaminoplatin, sodium (II) tetranitroplatinate, palladium chloride, palladium nitrate, palladium sulfate, diaminopalladium (II) hydroxide, tetraminopalladium (II) chloride, hexaminorodium chloride, rhodium carbonyl chloride, hydrated rhodium trichloride, rhodium nitrate, Sodium hexachlorodate (III) sodium hexanitrorodate (III), iridium tribromide, iridium dichloride, iridium tetrachloride, sodium hexanitroiridate (III), potassium or sodium chlorohydidate, rhodium or potassium oxalate, etc. The use of a platinum, iridium, rhodium or palladium chloride compound, such as chloroplatinic, chlorohydric or chloropalladic acid, is preferred; or hydrated rhodium trichloride, since it facilitates the incorporation of both the metal component of the platinum group and at least a minor amount of the preferred halogen compound in a single step. The hydrogen chloride or the like acid is also usually added to the impregnation solution in order to subsequently facilitate the incorporation of the halogen component and the uniform distribution of the metal components through the carrier material. In addition, it is generally preferred to impregnate the carrier material after it has been calcined to reduce the risk of washing out the valuable metal of the platinum group. In general, the metal component of the platinum group is dispersed homogeneously in the catalyst. The homogeneous dispersion of the metal of the platinum group is preferably determined through the Scanning Electron Microscope (STEM), comparing the concentrations of the metals with the overall metal content of the catalyst. In an alternative embodiment one or more components of the platinum group metal may be present as components of the surface layer as described in US Pat. No. 4,770,094, incorporated by reference. The "surface layer" is the layer of a catalyst particle adjacent to the surface of the particle, and the metal concentration of the surface layer graduates progressing from the surface toward the center of the catalyst particle. A metal of the lanthanide series is another essential component of the present catalyst. Inside of The lanthanide series include the following: lanthanum, cerium, praseodymium, neodymium, procycium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium. The favored elements are those that are able to form stable ions +2, that is, Sm, Eu and Yb (CRC Handbook of Chemistry and Physics TManual of Chemistry and Physics]), 75 ^ Edition 1994-1995, CRC Press, Inc.) being the ytterbium and the europium the preferred ones and especially the europium is preferred. The lanthanide component can usually be present in the catalytic compound in any form Catalytically available, such as for example elemental metal, a compound such as oxide, hydroxide, halide, oxyhalide, aluminate or in chemical combination with one or more of the other ingredients of the catalyst. Although it is not the purpose to restrict the present invention, it is believed that they are obtained best results when the lanthanide component is present in the compound in a form in which substantially all half of the lanthanide is in an oxidation state higher than that of the elemental metal, such as in the form of the oxide, oxyhalide or halide or in a mixture thereof, and the oxidation and reduction steps described below that are preferably used in the preparation of the instant catalyst compound are specifically designed to achieve this purpose. In a particularly advantageous embodiment, the steps of the preparation and the conditions are selected to carry out the form of a favored lanthanide that develops mainly stable ions +2 (ie, more than 50% of the lanthanide) such as for example SmO, EuO and / or YbO. Optimally, more than 80% is present in an atomic base of the lanthanide as the oxide +2, for example, the preferred europium as EuO. As the final reduction of the catalyst can be carried out at the site in the conversion unit, the catalyst of the invention can show either or both of the oxide ratios as manufactured or immediately before use in a conversion process. The metal component of the lanthanide can be incorporated into the catalyst in any amount that is catalytically effective, and good results are obtained with a lanthanide with a mass percentage of 0.05 to 5 in an elemental base in the catalyst. In general, better results are achieved with a lanthanide with a mass percentage of 0.2 to * 2, calculated on an elementary basis. The preferred atomic ratio of the lanthanide to the platinum group metal for this catalyst is at least 1.3: 1, preferably 1.5: 1 or more and especially 2: 1 to 5: 1. The lanthanide component is incorporated into the catalyst compound in any suitable manner known in the art, such as by coprecipitation, cogelling or co-extrusion with the porous carrier material, the exchange of ions with the gelled carrier material, or the impregnation of porous carrier material, either before, after or during the period in which it is dried and calcined. The purpose is to include within the scope of the present invention all conventional methods for incorporating and simultaneously distributing a metallic component in a catalytic compound in the desired manner, since the particular method of incorporation used is not considered as an essential feature of the present invention. Preferably the method used results in a Relatively uniform dispersion of the lanthanide moiety in the carrier material, although methods that result in a non-uniform distribution of the lanthanide are within the scope of the present invention. An appropriate method to incorporate the component of the The lanthanide in the catalytic compound involves the cogelling or coprecipitation of the lanthanide component in the form of the corresponding hydrated oxide or the oxyhalide during the preparation of the preferred carrier material: alumina. This method generally involves the addition of a sun-soluble or sun-dispersible compound of the lanthanide, such as, for example, lanthanide trichloride, lanthanide oxide and similar compounds to alumina hydrosol, and subsequently, the combination of hydrosol containing lanthanide with a suitable gelling agent and the dripping of the resulting mixture in an oil bath, etc. , as explained with details above. Alternatively, a lanthanide compound can be added to the gelling agent. After drying and calcination of the resulting gelled carrier material in the air, an intimate combination of alumina and lanthanide oxide and / or oxychloride is obtained. A preferred method for the incorporation of the lanthanide component in the catalytic compound involves the use of a soluble and unfolding lanthanide compound in solution to impregnate the porous carrier material. In general, the solvent used in this impregnation step is selected based on the ability to dissolve the desired lanthanum compound and to maintain it in solution until it is uniformly distributed through the carrier material without adversely affecting the carrier material or the other ingredients of the catalyst. Suitable solvents include alcohols, ethers, acids and the like, with an aqueous and acidic solution being preferred. Therefore, the lanthanide component can be added to the carrier material by mixing the carrier with an aqueous acid solution of a salt, a complex or a suitable lanthanide compound, such as a nitrate, chloride, fluoride, organic alkyl, hydroxide, oxide and compounds Similar. Suitable acids for use in the impregnation solution are: inorganic acids such as hydrochloric acid, nitric acid and the like, and strongly acidic organic acids such as oxalic acid, malonic acid, citric acid and the like. The lanthanide component can be impregnated within the carrier either before, simultaneously with, or after the metal component of the platinum group. As an alternative for the uniform distribution of the lanthanide in the carrier, a lanthanide metal of the surface layer can be incorporated in the catalyst particle in any suitable manner to carry out a decreasing gradient of the metal from the surface to the center of the particle. Preferably, the metal is impregnated within the support as a compound that decomposes with contact with the carrier, releasing the metal at or near the surface of the particle. Other means, which do not limit the invention, include the use of a metal compound that forms complexes with the carrier or does not penetrate into the interior of the particle. An example may be a multidentate binder, such as, for example, carboxylic acids or metal compounds containing amine groups, thiol groups, phosphide groups or other polar groups which can be strongly bound with an oxide support. Alternatively, the lanthanide metal can be incorporated into the catalyst by spray impregnation. Optionally, the catalyst may also include other components or mixtures thereof that act on their own or collectively as catalyst modifiers to improve activity, selectivity or stability. Some known modifiers of the catalyst include rhenium, indium, cobalt, nickel, iron, tungsten, molybdenum, chromium, bismuth, antimony, zinc, cadmium and copper. Catalytically effective amounts of the components can be added in any suitable manner to the carrier material during or after its preparation or in the catalyst compound before, during or after the other components are incorporated. An optional component of the catalyst, particularly useful in the hydrocarbon conversion embodiments of the present invention including the dehydrogenation, dehydrocyclization or hydrogenation reactions, is an alkali or a component of the alkaline earth metal. More precisely, this optional ingredient is selected from the group consisting of the compounds of the alkali metal, rubidium, • potassium, sodium and lithium - and the compounds of the alkaline earth metals: calcium, strontium, barium and magnesium. In general, good results are obtained in these embodiments when this component constitutes a mass percentage of 0.01 to 5 of the compound, calculated on an elementary basis. This alkali or optional alkaline earth metal component can be incorporated into the compound in any of the known ways, with impregnation being preferred with a solution aqueous of a suitable compound soluble in water and unfolding. As indicated until now, it is necessary to employ at least one oxidation step in the preparation of the catalyst. The conditions used to carry out the oxidation step are selected to substantially convert all metal components within the catalytic in its corresponding oxide form. The oxidation step is usually carried out at a temperature ranging from 370 ° to 600 ° C. In general, an oxygen atmosphere including air is used. Commonly, the step The oxidation will be carried out for a period ranging from 0.5 to 10 hours or more, the exact period of time being that required to substantially convert all metal components to their corresponding oxide form. This time, of course, will vary according to the oxidation temperature used and the oxygen content of the atmosphere used.

In addition to the oxidation step, it can also be used * One step of adjusting the halogen in the catalyst preparation. As indicated so far, the adjustment step of the halogen can serve as a double function. First, the step of adjusting the halogen can help the homogenous dispersion of the Group IVA metal (IUPAC 14) and other metal components. In addition, the adjustment step of the halogen can serve as a means to incorporate the desired level of halogen in the final catalytic compound. The adjustment step of the halogen employs a halogen or a halogen-containing compound in an atmosphere of air or oxygen. As the preferred halogen for incorporation into the catalyst compound includes chlorine, the halogen or the preferred halogen-containing compound used during the step of The adjustment of the halogen is chlorine, HCl or the precursor of these compounds. In carrying out the adjustment step of the halogen, the catalytic compound comes into contact with the halogen or halogen-containing compound in an atmosphere of air or oxygen at an elevated temperature ranging from 370 ° to 600 ° C. In addition, it is advisable to have water available during the passage of the contact in order to help the adjustment. In particular, when the halogen component of the catalyst includes chlorine, it is preferred to use a molal ratio of water with HCl from 5: 1 to 100: 1. The duration of the halogenation step is usually 0.5 to 5 hours or more. Due to the similarity of the conditions, the adjustment step of the halogen can be carried out during the oxidation step. Alternatively, the adjustment step of the halogen can be carried out before or after the oxidation step as required by the particular method used to prepare the catalyst of the invention. Without taking into consideration the exact adjustment step of the halogen used, the halogen content of the final catalyst should be such that sufficient halogen exists to include, in an elemental base, a mass percentage of 0.1 to 10 of the finished compound. When preparing the catalyst, it is also necessary to employ a reduction step. The reduction step is designed to substantially reduce all the metal component of the platinum group to the corresponding elemental metal state and ensure a relatively uniform and finely divided dispersion of its component through the refractory inorganic oxide. It is preferred that the step of the reduction be carried out in a substantially water-free environment. Preferably, the reducing gas is substantially pure and dry hydrogen (ie, less than a volume of 20 ppm of water). However, other reducing gases such as CO, nitrogen, etc. can be used. Commonly, the reducing gas comes into contact with the oxidized catalyst compound under conditions including a temperature reduction of 315 ° to 650 ° C for a period of time ranging from 0.5 to 10 or more ctive hours to substantially reduce the entire component of the catalyst. metal from the platinum group to the elemental metallic state. The step of the reduction can be carried out before loading the catalytic compound in the hydrocarbon conversion zone or it can be carried out on site as part of a process for starting the hydrocarbon conversion process. However, if the latter technique is employed, adequate precautions must be taken to pre-dry the hydrocarbon conversion plant in order to achieve a substantially water-free state and a reducing gas containing substantially water-free hydrogen should be employed. Optionally, the catalyst compound may be subjected to a presulfurization step. The optional sulfur component can be incorporated into the catalyst by any known technique. The catalyst of the present invention has a particular utility as a hydrocarbon conversion catalyst. The hydrocarbon to be converted comes into contact with the catalyst at the hydrocarbon conversion conditions, which include a temperature ranging from 40 ° to 300 °, a pressure ranging from atmospheric pressure to 200 absolute atmospheres (101.3 kPa a 20.26 mPa) and space velocities per hour of liquid from 0.1 to 100 hr-1. The catalyst is particularly suitable for the catalytic conversion of gasoline feedstock supplies, and may also be used for dehydrocyclization, isomerization of aliphatic and aromatic substances, dehydrogenation, hydrodisintegration, molecular disproportionation, dealkylation, alkylation, transalkylation, oligomerization and others. hydrocarbon conversions. In the preferred catalytic conversion embodiment, it is preheated and a hydrocarbon feedstock and a hydrogen-rich gas are charged in a conversion zone which generally contains 2 to 5 reactors in series. Suitable heating means are provided between the reactors to compensate for the net endothermic heating of the reaction in each of the reactors. The reagents can contact the catalyst in individual reactors either in the upflow, downflow or in a radial flow manner, with the radial flow mode being preferred. The catalyst is located within a fixed bed system, or preferably, in a mobile bed system with regeneration of the associated continuous catalyst. Alternative approaches for reactivating the deactivated catalyst are well known to those skilled in the art, and include semiregenerative operation in which the entire unit is stopped for catalyst regeneration and reactivation or operation in a rotating reactor in the reactor. which an individual reactor is isolated from the system, regenerated and reactivated while the other reactors remain in operation. The continuous regeneration of the preferred catalyst together with the mobile bed system are explained, inter alia, in United States Patents US-A-3647680; US-A-3652231; US-A-3692496; and US-A-4832291, all of which are incorporated herein by reference. The effluent from the conversion zone passes through the cooling media to a separation zone, which is usually kept at 0 ° to 65 °, where the hydrogen-rich gas is separated from the liquid stream commonly referred to as the "non-stabilized reformed product". The resulting hydrogen stream can then be recycled through suitable compression means back to the conversion zone. The liquid phase of the separation zone is usually removed and processed in a fractionation system in order to adjust the butane concentration, thereby controlling the volatility of the front end of the resulting reformed product. The operating conditions applied in the conversion process of the present invention include a pressure selected within the range of 100 kPa to 7 MPa (abs). Particularly good results are obtained with a low pressure, mainly a pressure of 350 to 2500 kPa (abs). The The conversion temperature is within the range of 315 ° to 600 ° C and preferably 425 ° to 565 ° C. As is well known to those skilled in the conversion art, the initial temperature selection within this wide range is mainly carried out as a function of the desired octane of the reformed product considering the characteristics of the charge supply and the catalyst . In general, the temperature increases slowly from this moment during the operation to compensate for the unavoidable deactivation that occurs to offer a constant octane product. Sufficient hydrogen is supplied to provide an amount of 1 to 20 moles of hydrogen per mole of hydrocarbon feed entering the conversion zone, with excellent results when 2 to 10 moles of hydrogen are used per mole of hydrocarbon feed. In the same way, the space velocity per hour of the liquid (LHSV) used in the conversion is selected from the range of 0.1 to 10 hr "1, with a value in the range of 1 to 5 hr-1 being preferred. The hydrocarbon that is charged to this conversion system is preferably a naphtha feed supply that includes naphthenes and paraffins that boil within the range of gasoline.The preferred feedstocks are naphthas consisting mainly of naphthenes and paraffins, in spite of that, in many cases, the aromatic substances will also be present.This preferred class includes direct distillation gasolines, natural gasolines, synthetic gasolines and similar products.As an alternative embodiment, it is often beneficial to charge thermal disintegrated gasolines or catalytically, partially reformed naphthas or dehydrogenated naphthas. direct distillation and disintegrated naphtha of the gasoline range to have advantage. The gasoline charge supply of the gasoline range can be a total boiling gasoline having an initial boiling point ASTM D-86 ranging from 40 to 80 ° C and a final boiling point in the range of 160 to 220 ° C, or it may be a selected fraction thereof which will generally be a higher boiling fraction, which is commonly referred to as heavy naphtha, for example, a naphtha which boils in the range of 100-200 ° C. If the conversion is directed to the production of one or more of the following: benzene, toluene and xylenes, the boiling range may be principally or substantially within the range of 60-150 ° C. In some cases, it is also an advantage to load pure hydrocarbons or mixtures of hydrocarbons that have been recovered from the extraction units - for example, the sharps from the extraction of aromatic substances or the direct-chain paraffins - which will become aromatic substances. It is generally preferred to use the present invention in a substantially water-free environment. An essential part for achieving this condition in the conversion zone is the control of the water level present in the power supply and the hydrogen current that is charged in the area. Generally better results are obtained when the total amount of water entering the conversion zone from any source is maintained at a level below 50 ppm and preferably below 20 ppm, expressed as the weight of the equivalent water in the power supply. In general, this can be achieved by careful control of the water present in the feed supply and in the hydrogen stream. The feed supply can be dried using any suitable drying means known in the art, such as for example a conventional solid adsorbent having a high water selectivity; for example crystalline sodium or calcium aluminosilicates, silica gel, activated alumina, molecular sieves, anhydrous calcium sulfate, sodium with high surface area and similar adsorbents. Likewise, the water content of the feed supply can be adjusted by suitable extraction operations in a fractionation column or similar device. In some cases, a combination of the adsorbent drying and the distillation drying may be used in a beneficial manner to carry out the almost complete removal of the water from the feed supply. Preferably, the power supply is dried at a level corresponding to less than 20 ppm H20 equivalent. It is preferred to maintain the water content of the hydrogen stream entering the hydrocarbon conversion zone at a level of 10 to 20 ppm volume or less. In cases where the water content of the hydrogen stream is higher than this range, this can be conveniently achieved by contacting the hydrogen stream with a suitable desiccant, such as those mentioned above under conventional drying conditions. A preferred practice is to use the present invention in a substantially sulfur-free environment. Any control means known in the art can be used to treat the naphtha feed supply that will be charged to the reaction zone of the conversion. For example, the power supply may be subject to adsorption processes, catalytic processes or combinations thereof. The adsorption processes can employ molecular sieves, silica, aluminas with high surface area, carbon molecular sieves, crystalline aluminosilicates, activated carbons, compositions containing metallic areas with high surfaces, such as nickel or copper and the like. It is preferred that these feedstocks be treated by conventional catalytic pretreatment methods, such as by way of example hydrorefining, hydrotreating, ^ hydrodesulfurization, etc. , to eliminate substantially all the pollutants produced by sulfur, nitrogen and water and to saturate any olefin that could be contained therein. The catalytic processes can employ traditional sulfur reducing catalyst formulas, known in the art and including refractory inorganic oxide supports containing metals selected from the group including Group VI-B (6), Group 10 II-B (12 ), and Group VIII (IUPAC 8-10) of the Periodic Table. One embodiment of the invention involves the process of converting a naphtha feed supply under conditions of catalytic dehydrocyclization. In particular, the preferred naphtha feedstock includes C6-C8 non-aromatic hydrocarbons. The dehydrocyclization conditions include a pressure of 100 kPa to 4 MPa (abs), the preferred pressure being 200 kPa to 1.5 MPa, a temperature ranging from 350 ° to 650 ° C and a space velocity per hour of the liquid going from 0.1 to 10 hr "1. Preferably, 20 hydrogen can be used as a diluent.When it is present, hydrogen can be circulated at a rate of 0.2 to 10 moles of hydrogen per mole of hydrocarbon from the feed supply. of the naphtha in the embodiment of the alternative dehydrocyclization process includes a high proportion of t-paraffins, since the purpose of a dehydrocyclization process is to convert the paraffins into aromatic substances, due to the high value of the substances aromatic C6-C8, it is further preferred that the feed supply of the naphtha include C6-C8 paraffins. However, despite this preference, the naphtha feed supply may include naphthenes, aromatics and olefins in addition to the C6-C8 paraffins. Bf 10 Example I A spherical catalyst of the prior art which included platinum and tin in alumina was prepared by conventional techniques as a control catalyst to compare against the catalysts of the invention. He joined tin in the alumina sol according to the prior art, and the tin-containing alumina sol was subjected to the oil drip method to form 1.6 mm spheres which were vaporized to 10% LOI and calcined to 650 ° C. Subsequently the spherical support was impregnated with acid chloroplatinic in HCl to provide a mass percentage of 0.38 Pt in the finished catalyst. The impregnated catalyst was dried and oxychlorinated at 525 ° C with 2M HCl in air and reduced with pure hydrogen at 565 ° C. The finished control was designated as Catalyst 25 X and had the following approximate arrangement in mass percentage: Platinum 0.38 Tin 0.3 Example II 5 A spherical catalyst was prepared which included platinum, ytterbium and tin in the alumina to demonstrate the characteristics of the invention. Tin was incorporated into the alumina sol according to the prior art, and the tin-containing alumina sol was subjected to the drip method of oil to form 1.6 mm spheres that were vaporized until dried at 10% LOI and calcined at 650 ° C. Subsequently the spherical support was impregnated with ytterbium nitrate in 3.5% nitric acid to provide 1.1% Yb in the finished catalyst at a ratio of the solution to the support of 1: 1.

The resulting compound was vaporized to dryness (10% LOI) and calcined at 650 ° C with 3% steam. The resulting calcined compound was impregnated with chloroplatinic acid in HCl to provide a mass percentage of 0.38 Pt in the finished catalyst. The impregnated catalyst was dried and oxidized to 525 ° C with 2M HCl in air and reduced with pure H20 at 565 ° C. The catalyst containing finished Yb was designated as Catalyst A and had the following approximate composition in mass percentage: Iterbio 1.1 25 Platinum 0.38 Tin 0.3 Other catalysts containing lanthanum, samarium and dysprosium were prepared in the same manner as the catalyst containing ytterbium . The lanthanide contents of the finished catalysts were as follows, where each catalyst had substantially the same contents of tin and platinum as Catalyst A: Catalyst B Mass percentage 0.9 Catalyst C Mass percentage 1.0 Sm Catalyst D Mass percentage 1.1 Dy Example III Tests were structured in the pilot plant to compare the selectivity for the aromatic substances in a conversion process of the catalysts of the invention and of the prior art. The tests were based on the conversion of naphtha on the catalysts at a pressure of 0.8 MPa (abs), a space velocity per hour of the liquid of 3 hr_1 and a molal hydrogen / hydrocarbon ratio of 8. A conversion range was studied varying The temperature to provide data points at 502 ° C, 512 ° C, 522 ° C and 532 ° C. The naphtha for the comparative tests was naphtha derived from hydrotreated petroleum, derived from crude oil containing paraffin and asphalt, with the following characteristics: Specific gravity 0.737 Distillation, ASTM D-86, ° C IBP 87 # 10% 97 50% 116 90 % 140 5 EP 159 Percent mass of paraffins 60 naphthenes 27 aromatics 13 The results are shown as yield of the 10 aromatics against the performance of C5 + in Figure 1 for Catalysts A, B, C, D, and X The yield of the aromatic substances is defined as the yield of mass-percentage of (benzene + toluene + aromatic substances C8 + C9 + aromatic substances). As in general a high yield of the aromatic substances is the main objective of the catalytic conversion, the high yield of the aromatic substances in relation to the yield of the C5 + is an indication of a high selectivity. The catalysts A, B, C and D of the invention show a yield of aromatic substances of 2-3% higher at the same yield of C5 +. Example IV Tests were structured in the pilot plant to compare the selectivity and activity of Catalyst C and X for the conversion of a feed supply of naphtha. The naphtha for the comparative tests is the same as that used in Example III. Each test was based on the conditions of the conversion that included a pressure of 0.8 MPa (abs), a space velocity per hour of the liquid of 3 hr-1 and a hydrogen / hydrocarbon ratio of 8. A conversion range was studied varying the temperature to provide several data points at 502 ° C, 512 ° C, 522 ° C and 532 ° C. The conversion of (paraffins + naphthene) at each temperature was 2-4% higher for catalyst X, but the selectivity as yield of the C5 + product was greater over the entire conversion range for Catalyst C. The diagram of selectivity against the conversion is shown as Figure 2. Example V Three spherical catalysts containing platinum, europium and tin were prepared in the alumina to demonstrate the characteristics of the invention. Tin was incorporated into a spherical alumina support according to the prior art as described in Example II. Subsequently the spherical support was impregnated with europium nitrate in 3.5% nitric acid to provide three different Eu levels in the finished catalyst at a solution to support ratio of 1: 1. The resulting compounds were vaporized until dried (10% LOI) and calcined at 650 ° C with 3% steam. The resulting calcined compounds were impregnated with chloroplatinic acid in HCl to provide a mass percentage of 0.38 Pt in the finished catalyst. The impregnated catalysts were dried and oxychlorinated at 525 ° C with 2M HCl in air and reduced with pure H2 at 565 ° C. The catalysts containing Eu ends were designated as E, F and G Catalysts and had the following approximate composition in mass percentage: Europium EFG Catalyst 0.30 0.51 1.1 Platinum 0.37 0.37 0.38 Tin 0.3 0.3 0.3 Example VI Catalyst G was tested in comparison with Catalyst X of the technique to determine the presence of EuO according to the reduction. A programmed reduction procedure was carried out with the temperature using 5 mol -% H2 in Ar, with an increase in ambient temperature to 600 ° C at a rate of 10 ° C per minute. The hydrogen consumption for Catalyst G exceeded that of Catalyst X at 33 μmoles / gram, indicating a reduction of more than 90% Eu + 3 to Eu + 2. Example VII Tests were structured in the pilot plant to compare the selectivity and activity of Catalyst E, F and G with that of Catalyst X for the conversion of a naphtha feed supply. The naphtha for the comparative tests was the same as for Example III.

^? Each test was based on the conversion conditions r that included a pressure of 0.8 MPa (abs), an hourly space velocity of the liquid of 3 hr_1 and a hydrogen / hydrocarbon ratio of 8. A conversion range of 5 was studied varying the temperature to offer several data points each at 502 ° C, 512 ° C and 532 ° C. The comparative conversion (of the paraffins + naphthene), the yield of the C5 + product and the yield of the aromatic substances are then expressed in mass percentage. Conversion 79.5 75.6 70.1 58.9 Yield of C5 + 89.5 91.6 92.9 96.2 Yield of aromatic substances 65.8 65.1 61.5 52.2 15 512 ° CXEFG Conversion 84.7 81.2 76.9 65.3 Yield of C5 + 88.1 90.0 91.7 95.2 Yield of aromatic substances 68.8 68.4 66.6 58.3 20 522 ° CXEFG Conversion 88.1 85.2 82.3 70.8 Yield of C5 + 86.7 88.8 90.3 94.0 Yield of aromatic substances 70.0 70.3 69.6 62.9 25 532 ° CXEFG Conversion 91.6 89.2 86.6 75.5 Yield of C5 + 85.2 87.4 88.9 92.6 Yield of aromatic substances 71.5 72.0 71.9 66.6 Figure 3 is a performance diagram of the aromatic substances against the performance of C5 + which is derived from the above values, showing higher yields in the aromatic substances in the same yields of C5 + for the catalysts of the invention. Activity and selectivity ratios were developed from the above values and illustrated in Figure 4. The activity was calculated as the percentage decrease in the conversion of Catalyst X base for each temperature, and plotted against the ratio Atomic of Eu / Pt for the respective catalysts. The selectivity was derived from Figure 3 by measuring the change in the yields of aromatic substances between the catalysts over a common range of C5 + yields and dividing by the yield of C5 +, that is, an average yield of the aromatic substances? expressed as a percentage of the performance of C5 +. When tracing the latter in Figure 4, the extension of the line to the high Eu / Pt ratio of Catalyst G is shown as a lighter line since there is only a small overlap of the Catalyst G line with those of the others catalysts in Figure 3. Figure 4 shows an accelerated drop in the conversion with the increase in the content of the europium in the catalyst as the Eu / Pt ratio increases between 1 and 2, and the inclination becomes even higher over a ratio of 2. The relation of selectivity to the Eu / Pt ratio, on the other hand, is a bit more linear. Although the selection of a Eu / Pt ratio would depend on the relative importance of the selectivity and activity, very high ratios would incur a heavier activity penalty in relation to the advantage of the selectivity.

Claims (1)

CLAIMS: 1. A catalytic compound that includes a combination of a refractory inorganic oxide support with a mass percentage of 0.01 to 5 in an elemental base of a 5 metal component of the IVA Group (IUPAC 14), a mass percentage of 0.01 to 2 on an elemental basis of a metal component of the platinum group, and a mass percentage of 0.05 to 5 on an elemental basis of a component of europium, in which more than 50% of the europium is present as EuO. The catalyst compound of Claim 1 wherein the refractory inorganic oxide includes alumina. 3. The catalytic compound of the Claims 1 or 2 in which the metal component of the platinum group includes a platinum component. 4. The catalytic compound of any of the Claims 1 to 3, wherein the metal component of the IVA Group (IUPAC 14) includes a component of tin. 5. The catalytic compound of any of the Claims 1 to 4, wherein the atomic ratio of europium to the metal of the platinum group is at least

1. 3. 6. The catalytic compound of any of the Claims 1 to 5 which further include a halogen component. 7. The catalytic compound of Claim 6 wherein the halogen component includes a chlorine component. 8. A process for catalytic conversion of a naphtha feed supply that includes contacting the feed supply under conversion conditions that include a temperature of 425 ° C to 565 ° C, a pressure of 350 to 2500 kPa (ga) , an hourly space velocity of the liquid of 1 to 5 hr _1 and a molal ratio of hydrogen with hydrocarbon feed of 2 to 10, wherein the catalytic compound is defined in any of Claims 1 to 7.