RU2186622C2 - Catalyst of hydrocarbon conversion, method of catalytic reforming of parent naphtha using catalyst - Google Patents

Abstract

FIELD: oil processing, chemical technology, catalysts. SUBSTANCE: invention relates to catalytic reforming of naphtha. Invention describes a novel catalyst and its using in the process of hydrocarbon conversion. Catalyst comprises refractory inorganic oxide, metal of platinum group IVA (IUPAC 14) and europium taken in the definite ratio. The use of this catalyst results to significant improvement of selectivity to required gasoline or aromatic product. EFFECT: improved properties of catalyst. 6 cl, 4 dwg, 7 ex

Description

 The object of the present invention is a new bifunctional catalytic composite, characterized by a combination of three or more metals in a certain concentration in the final catalyst and its use in the conversion of hydrocarbon. Catalysts having both a hydrogenation-dehydrogenation function and a cracking function are widely used in many applications, especially in the oil and petrochemical industries, to accelerate a wide range of hydrocarbon conversion reactions. Cracking function usually refers to the acidic substances of the porous, adsorbing, refractory oxide type, which are usually used as a substrate or carrier for a component of a heavy metal, such as metals of group VIII (IUPAC 8-10) groups, which primarily contribute to the function hydrogenation-dehydrogenation. Other metals in bound or elemental form can affect one or both functions - cracking and hydrogenation-dehydrogenation.

 In another aspect, the present invention encompasses improved methods that come from the use of new catalysts. These dual-function catalysts are used to accelerate a wide variety of hydrocarbon conversion reactions such as dehydrogenation, hydrogenation, hydrocracking, hydrogenolysis, isomerization, desulfurization, cyclization, alkylation, polymerization, cracking and hydroisomerization. In a specific aspect, an improved reforming process utilizes the catalyst in question to improve selectivity to gasoline and aromatic products.

 Catalytic reforming involves a number of competing processes or reaction sequences. These include dehydrogenation of cyclohexanes to aromatics, dehydroisomerization of alkyl cyclopentanes to aromatics, dehydrocyclization of acyclic hydrocarbons to aromatics, hydrocracking of paraffins to light products boiling outside the gasoline range, dealkylation of alkyl benzenes and isomerization of paraffins. Some reactions that occur during reforming, such as hydrocracking, which produce light paraffin gases, have a detrimental effect on the yield of products boiling in the gasoline range. Improvements in catalytic reforming processes are thus aimed at enhancing these reactions, giving a high yield of gasoline fraction at a given octane number.

It is especially important that catalysts with a dual function exhibit the ability both to efficiently perform their specific functions initially and to fulfill them satisfactorily over long periods of time. The parameters used in this field to measure how well a particular catalyst performs its intended functions in a particular hydrocarbon reaction medium are activity, selectivity and stability. In a reforming environment, these parameters are defined as follows:
(1) Activity is a measurement of the ability of a catalyst to convert hydrocarbon reagents to products at a given level of stiffness with a level of stiffness representing a combination of reaction conditions: temperature, pressure, contact time, and partial pressure of hydrogen. Activity is usually calculated as the octane number of pentanes and the heavier ("C ₅ ⁺ ") product stream from a given feed stream at a given stiffness level, or vice versa, as the temperature required to achieve a given octane number.

(2) Selectivity refers to the percentage yield of petrochemical aromatic compounds or C ₅ ⁺ gasoline products from a given feed stream at a specific activity level.

(3) Stability refers to the rate of change in activity or selectivity per unit time or processed feedstock. Activity stability is usually measured as the rate of change of operating temperature per unit time or feedstock to achieve a given octane rating of a C ₅ ⁺ product, with a lower rate of temperature change corresponding to better stability of activity, since catalytic reforming units usually operate at a relatively constant octane rating of the product. The stability of selectivity is measured as the rate of decrease in the yield of aromatic compounds or C ₅ ⁺ product per unit time or feedstock.

 Programs to improve the performance of reforming catalysts are stimulated by reformulating gasoline following the widespread removal of lead antiknock additives to reduce harmful vehicle emissions. Refining methods for gasoline, such as catalytic reforming, must work at higher efficiency with greater flexibility in order to meet these changing requirements. The selectivity of the catalyst becomes even more important for given gasoline components for these requirements, while avoiding the loss of less valuable products. The main problem encountered by specialists in this field, therefore, is the development of more selective catalysts, while at the same time maintaining effective activity and stability of the catalyst.

 Many multimetal catalysts are known for the catalytic reforming of petroleum feedstocks. Most of them include a choice of platinum group metals, rhenium and group IVA metals (IUPAC 14).

 US patent US-A-3915845 discloses the conversion of hydrocarbons using a catalyst containing a platinum group metal, a group IVA metal, a halogen and a lanthanide in an atomic ratio to a platinum group metal from 0.1 to 1.25. Preferred lanthanides are lanthanum, cerium, and especially neodymium. US patent US-A-4039477 discloses a catalyst for the catalytic hydrotreatment of hydrocarbons containing a refractory metal oxide, a platinum group metal, tin and at least one metal from yttrium, thorium, uranium, praseodymium, cerium, lanthanum, neodymium, samarium, dysprosium and gadolinium with favorable results observed at relatively low ratios of the latter metals to platinum. US patent US-A-5254518 discloses a catalyst containing a Group VIII noble metal, Group IVB oxide and amorphous silica-alumina on which a rare earth metal oxide, preferably Nd or Y, is supported.

SUMMARY OF THE INVENTION
The objective of the invention is to provide a new catalyst for improved selectivity in the conversion of hydrocarbons. A further object of the invention is to provide a reforming process having improved selectivity for the yield of gasoline or aromatic compounds.

 The invention more particularly proceeds from the discovery that a catalyst containing platinum, tin or europium on a halogenated alumina shows a favorable aromatization to cracking ratio in a hydrocarbon reforming reaction.

 The main embodiment of the present invention is a catalyst containing a refractory inorganic oxide, a metal of group IVA (IUPAC 14), a metal of a platinum group and a metal of a number of lanthanides. The atomic ratio of the lanthanide metal to the platinum group metal is preferably at least 1.3, more preferably 1.5 or more, and most preferably from 2 to 5. The catalyst optimally also preferably contains halogen, especially chlorine. In preferred embodiments, the refractory inorganic oxide is alumina, the platinum group metal is platinum, the group IVA metal (IUPAC 14) is tin, a metal of the lanthanide series is selected from at least europium and ytterbium. A particularly preferred catalyst contains tin, platinum and europium, mainly in the form of EuO on an alumina support.

In another aspect, the invention provides a method for converting a hydrocarbon feed using the present catalyst. A preferred hydrocarbon conversion is the catalytic reforming of petroleum feedstocks using the catalyst of the present invention to increase the yield of gasoline and / or aromatics. The conversion, more preferably, contains dehydrocyclization of the day increasing the yield of aromatic compounds. Optimally, the petroleum feed contains hydrocarbons in the range of C ₆ -C ₈ , which produce one or more of benzene, toluene and xylene, in a catalytic reforming unit.

Brief Description of the Drawings
FIG. 1 compares the yields of cracking and flavoring, processing petroleum feedstocks using the prior art catalysts and the catalysts of the present invention.

 FIG. 2 compares reforming selectivity for prior art catalysts and the catalysts of the present invention in the processing of petroleum feedstocks.

Figure 3 shows the yield of C ₅ ⁺ depending on aromatic compounds for the three Eu-containing catalysts compared to a reference catalyst not containing Eu.

 FIG. 4 depicts the relative activity and selectivity of Eu-containing catalysts as a function of the Eu content.

Description of Preferred Embodiments
The main embodiment of the present invention, therefore, is a catalyst containing a carrier of a refractory inorganic oxide, at least one Group IVA metal (IUPAC 14) of the Periodic Table (See Cotton and Wilkinson, Advanced Inorganic Chemistry, Jonn Wiley & Sons (Fifth Edition, 1988), a platinum group metal and a metal of the pantanoid series.

The refractory support used in the present invention is typically porous, adsorbent, with a large surface area, the support having a surface area of 25 to 500 m ² / g. The porous support material must also be uniform in composition and relatively refractory to the conditions used in the hydrocarbon conversion process. The term "uniform in composition" means that the substrate must be non-layered, not have gradients of particle concentration inherent in its composition, and completely homogeneous in composition. Thus, if the substrate is a mixture of two or more refractory substances, the relative amounts of these substances must be constant and uniform in the entire volume of the carrier. The carrier substances that are traditionally used in dual function hydrocarbon conversion catalysts are intended to be included within the scope of the present invention:
(1) refractory inorganic oxides such as magnesium oxide, titanium dioxide, zirconia, chromium oxide, zinc oxide, thorium oxide, boron oxide, silicon dioxide-alumina, silicon dioxide-magnesium oxide, chromium oxide-alumina, aluminum oxide boron oxide, silicon dioxide, zirconia, etc.,
(2) ceramics, porcelain, bauxite,
(3) silicon dioxide or silica gel, silicon carbide, clays and silicates that are synthetically prepared or are in natural form, which may or may not be treated with acid, for example attapulgite, diatomaceous earth, fuller’s earth, kaolin or kieselguhr,
(4) crystalline zeolite aluminosilicates such as X-zeolite, Y-zeolite, mordenite, β-zeolite, Ω-zeolite or L-zeolite, either in hydrogen form or, more preferably, in non-acid form with one or more alkali metals, located in cation exchange centers
(5) non-zeolitic molecular sieves such as aluminophosphates or aluminosilicophosphates, and
(6) combinations of one or more substances from one or more of these groups.

Preferably, the refractory carrier comprises 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 known as gamma, eta, and tetta alumina, with gamma or eta alumina giving better results. A preferred refractory inorganic oxide will have an apparent bulk density of from 0.3 to 1.0 g / cm ³ and the surface area is characterized so that the average pore diameter is 20-300 angstroms, the pore volume is 0.1-1 cm ³ / g and the surface area is 100-500 m ² / g.

 Concerning the fact that alumina is a preferred refractory inorganic oxide, a particularly preferred alumina is that which is described in US-A-3852190 and US-A-401 2313 as a by-product of the Ziegler reaction of the synthesis of higher alcohols, as described in US-A- 2892858. For the sake of simplicity, such alumina will hereinafter be referred to as "Ziegler alumina". Ziegler alumina is currently marketed by Vista Chemical Company under the trademark "Catapal" or Condea Chemie GmbH under the trademark "Pural". This material is extremely high-purity pseudoboehmite, which after firing at high temperature gives high-purity gamma-alumina.

 Alumina powder can be formed into any desired shape or type of carrier material known to those skilled in the art, such as spherical, in the form of rods, granules, balls, tablets, extrudates, and the like. forms, methods known to those skilled in the art of forming a catalyst substance.

A preferred form of catalyst support of the present invention is spherical. Alumina spheres can be made continuously by a well-known oil-drop method, which comprises: producing an aluminum oxide hydrosol by any known method and, preferably, by reacting aluminum metal with hydrochloric acid; combining the resulting hydrosol with a suitable gelling agent; and dripping the resulting mixture into an oil bath, which is maintained at elevated temperatures. The droplets of the mixture remain in the oil bath until they solidify and form spheres (balls) of the hydrogel. The balls are then continuously removed from the oil bath and are usually subjected to specific aging treatments (aging) and drying in oil and an ammonia solution to further improve its physical characteristics. The obtained aged and thickened particles are then washed and dried at a relatively low temperature of 150-205 ^o C and subjected to the calcination procedure at a temperature of 450-700 ^o C for 1-20 hours. This treatment causes the conversion of the alumina hydrogel to the corresponding crystalline gamma alumina. US-A-2620314 provides further details and is incorporated herein by reference.

An alternative form of carrier material is a cylindrical extrudate, preferably prepared by mixing alumina powder with water and suitable peptizing agents such as HCl until an extrudable paste forms. The amount of water added to form a paste is usually sufficient to obtain a calcination loss (LOI) at 500 ^° C. of 45-65 wt.%, With a value of 55 wt.% Being preferred. The acid addition rate is usually sufficient to obtain 2-7 wt.% Volatile alumina powder used in the mixture, with a value of 3-4 wt.% Is preferred. The resulting paste is extruded through a die of a suitable size to form extrudate particles. These particles are then dried at a temperature of 260-427 ^{° C.} for 0.1-5 hours to form extrudate particles. Preferably, the refractory inorganic oxide contains essentially pure Ziegler alumina having an apparent bulk density of 0.6-1 g / cm ³ and a surface area of 150-280 m ² / g (preferably 185-235 m ² / g at pore volume 0.3-0.8 cm ³ / g).

Group IVA metal (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, with tin being particularly preferred. This component may be present in the form of an elemental metal, in the form of a chemical compound, such as oxide, sulfide, halide, oxychloride, etc., or in the form of a physical or chemical combination with a porous support material and / or other components of the catalytic composite. Preferably, a substantial portion of the Group IVA metal (IUPAC 14) is present in the final catalyst with an oxidation state higher than that of the elemental metal. The metal component of group IVA (IUPAC 14) is optimally used in an amount sufficient to obtain the final catalytic composite containing 0.01-5 wt.% Metal, calculated on an elemental basis, with better results obtained at metal levels of 0.1-2 wt. .%
The metal component of Group IVA (IUPAC 14) can be introduced into the catalyst by any suitable method to achieve a homogeneous dispersion, such as co-precipitation with a porous support material, ion exchange with the support material, or impregnation of the support material at any stage of preparation. A method of incorporating a Group IVA metal component (IUPAC 14) into a catalytic composite comprises using a soluble decomposable Group IVA metal compound (IUPAC 14) to impregnate and disperse the metal into a porous support material. The metal component of Group IVA (IUPAC 14) can be impregnated either before, simultaneously with, or after other components are added to the carrier material. Thus, the metal component of Group IVA (IUPAC 14) can be added to the support material by mixing the latter with an aqueous solution of a suitable metal salt or soluble compound, such as tin dibromide, tin bivorous, tin tetrachloride, tin tetrachloride pentahydrate; or germanium oxide, germanium tetraethoxide, germanium tetrachloride; or lead nitrate, lead acetate, lead chlorate, and the like. connections. The use of Group IVA metal chloride compounds (IUPAC 14), such as tin tetrachloride, germanium tetrachloride or lead chlorate, is particularly preferred since it facilitates the incorporation of both the metal component and at least a small amount of the preferred halogen component on one stage. When combined with hydrogen chloride during the particularly preferred alumina peptization step described above, a homogeneous dispersion of the Group IVA metal component is obtained in accordance with the present invention (IUPAC 14). In an alternative embodiment, organic metal compounds such as trimethipol chloride and tin dichloride are introduced into the catalyst during peptization of an inorganic oxide binder, most preferably during peptization of alumina with hydrogen chloride or nitric acid.

 Another essential ingredient of the catalyst is the platinum group metal component. This component contains platinum, palladium, ruthenium, rhodium, iridium, osmium, or a mixture thereof, platinum is preferred. The platinum group metal may be in the final catalyst composite in the form of a compound, such as an oxide, sulfide, halide, oxyhalide and the like, in chemical combination with one or more other ingredients of the composite or in the form of an elemental metal. The best results are obtained when essentially all of these components are present in an elementary state and are uniformly dispersed in the carrier material. This component may be present in the final catalytic composite in any amount that is catalytically effective, the platinum group metal usually contains from 0.01 to 2 wt. % of the final catalytic composite, calculated on an elemental basis. Excellent results are obtained when the catalyst contains from 0.05 to 1 wt.% Platinum.

 The platinum group metal component can be incorporated into the porous support material by any suitable method, such as co-precipitation, ion exchange, or impregnation. A preferred method for preparing the catalyst involves the use of a soluble degradable compound of a platinum group metal to impregnate the support material in a relatively uniform manner. For example, the component may be added to the carrier by mixing the latter with an aqueous solution of platinum chloride or iridium hydrochloride or palladium hydrochloric acid. Other water-soluble compounds or metal complexes of the platinum group can be used in impregnating solutions and include ammonium chloroplatinate, platinum-bromosulfuric acid, platinum trichloride, platinum tetrachloride hydrate, dichlorocarbonyl platinum dichloride, platinum dinitrodiaminoplatinum, sodium tetranitrodirate platinum nitrate tetra nitrate nitrate. palladium, palladium sulfate, diamminopalpadia (II) hydroxide, tetraminopalladium (II) chloride, hexammorodium chloride, rhodium carbonyl chloride, rhodium trichporide hydrate, rhodium nitrate, hexachlo Rodat (III) sodium geksanitrorodat (III) sodium, iridium tribromide, iridium dichloride, iridium tetrachloride, geksanitroiridat (III) sodium, potassium or hloriridat sodium, potassium, etc. rodiyoksalat The use of a chloride compound of platinum, iridium, rhodium or palladium, such as platinum chloride, iridium hydrochloride or palladium hydrochloric acid or rhodium trichoride hydrate is preferred, as it facilitates the incorporation of both the metal component of the platinum group and at least a small amount of the preferred halogen component into one stage. Hydrochloric or similar acid is usually added to the impregnation solution in order to further facilitate the incorporation of the halogen component and the uniform distribution of the metal components in the carrier material. In addition, it is usually preferable to impregnate the carrier material after calcining to minimize the risk of leaching of the valuable platinum group metal.

 Typically, the platinum group metal component is uniformly dispersed in the catalyst. The homogeneous dispersion of the metal of the platinum group is preferably determined by a scanning transmission electron microscope (STEM), comparing the concentration of metals with the total metal content in the catalyst. In an alternative embodiment, one or more metal components of the platinum group may be present as a component of the surface layer, as described in US-A-4677094, incorporated herein by reference. The term "surface layer" refers to a layer of catalyst particles adjacent to the surface of the particles, and the concentration of the metal of the surface layer decreases from the surface to the center of the catalyst particle.

 The metal of the lanthanide series is another essential component of the present catalyst. A number of lanthanides include lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium. Favorable elements are those that are capable of forming stable +2 ions, i.e. Sm, Eu and Yb (CRC Handbook of Chemistry and Physics, 75th edition 1994-1995, CRC Press, Inc.), with ytterbium and europium being preferred, and europium being particularly preferred. Lanthanoid components can generally be present in a catalytic composite in any catalytically accessible form, such as an elemental metal, a compound such as an oxide, hydroxide, halide, oxyhalide, aluminate, or in chemical combination with one or more other catalyst ingredients. Although not intended to limit such a limitation of the present invention, it is contemplated that the best results are obtained when the lanthanoid component is present in the composite in a form where substantially all of the lanthanoid components are in an oxidation state higher than an elemental metal such as an oxide, an oxyhalide or halide or a mixture thereof, and in the following oxidation and reduction steps, which are preferably used in the preparation of the present catalytic composite, are especially intended to achieve this goals. In a particularly advantageous embodiment, the preparation steps and conditions are selected to obtain a favorable lanthanide form, which forms mainly stable +2 ions (i.e., more than 50% lanthanides), such as SmO, EuO and / or YbO. Optimally, more than 80% of the atomic base of lanthanides is present in the form of +2 oxide, for example the preferred europium in the form of EuO. Since the final reduction of the catalyst can be carried out in situ in a reforming unit, the catalyst of the invention can detect such proportions of oxides either upon receipt or immediately prior to its use in the reforming process.

 Metallic lanthanoid components can be incorporated into the catalyst in any amount that is catalytically effective; good results are obtained with 0.05 to 5 wt.% Elemental-based lanthanides in the catalyst. The best results are usually achieved with lanthanides from 0.2 to 2 wt.% Calculated on an elemental basis. The preferred atomic ratio of lanthanides to the platinum group metal for this catalyst is at least 1.3: 1, preferably 1.5: 1 or more, especially from 2: 1 to 5: 1.

 The lanthanoid component is introduced into the catalytic composite by any known suitable method, such as by co-precipitation, co-thickening, or co-extrusion with a porous carrier material, ion exchange with a gel-formed carrier material or impregnation of a porous carrier material either after, before, or during drying and calcination. All known methods of introducing and simultaneously distributing the metal component into the catalyst composite in the required manner are included within the scope of the present invention, so that the particular method of introduction used is not intended as an essential feature of the present invention. Preferably, the method used results in a relatively uniform dispersion of the lanthanoid component in the carrier material, although methods that result in an inhomogeneous distribution of lanthanides are within the scope of the present invention.

 One suitable method for introducing the lanthanide component into the catalytic composite involves co-thickening or co-precipitating the lanthanide component in the form of the corresponding aqueous oxide or oxyhalide during the preparation of the preferred carrier material, alumina. This method typically involves adding a suitable sol-soluble or sol-dispersible lanthanide component, such as lanthanide trichloride, lanthanide oxide, and the like to the alumina hydrosol, and then combining the lanthanide-containing hydrosol with a suitable gelling agent and burying the resulting mixture in an oil bath, etc. ., as explained in detail above. Alternatively, the lanthanoid compound may be added to the gelling agent. After drying and calcining the obtained gel substance of the carrier in air, a dense combination of alumina and lanthanide oxide and / or oxychloride is obtained.

 One of the preferred methods for incorporating the lanthanide component into the catalytic composite involves using a soluble degradable lanthanide compound in solution to impregnate the porous support material. Typically, the solvent used in this impregnation step is selected based on its ability to dissolve the desired lanthanide compound and keep it in solution until it is equally distributed throughout the support material without adversely affecting the support material or other catalyst ingredients. Suitable solvents contain alcohols, ethers, acids and the like, with an aqueous acidic solution being preferred. Thus, the lanthanoid component can be added to the carrier material by mixing the carrier with an aqueous acidic solution of a suitable lanthanide salt, complex or compound, such as nitrate, chloride, fluoride, organic alkyl, hydroxide, oxide, and the like. connections. 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 lanthanoid component may be impregnated into the carrier either before, simultaneously with, or after the platinum group metal component.

 As an alternative to the uniform distribution of the lanthanide in the support, the lanthanide metal of the surface layer can be incorporated into the catalyst particles by any method suitable for effecting a decreasing gradient of the metal from the surface to the center of the particle. Preferably, the metal is impregnated into the carrier in the form of a compound that decomposes upon contact with the carrier, releasing the metal at or near the surface of the particle. Other agents that do not limit the invention include the use of a metal compound that complexes with the carrier or which does not penetrate into the particles. An example is a multigentant ligand, such as carboxylic acids or metal compounds containing amino groups, thiol groups, phosphorus groups or other polar groups that can strongly bind to the oxide carrier. Alternatively, the lanthanoid metal may be incorporated into the catalyst by spray impregnation.

 Optionally, the catalyst may also contain other components or mixtures thereof, which act alone or in conjunction as catalytic modifiers to improve activity, selectivity or stability. Some well-known catalytic modifiers include rhenium, indium, cobalt, nickel, iron, tungsten, molybdenum, chromium, bismuth, antimony, zinc, cadmium and copper. Catalytically effective amounts of these components can be added in any suitable way to the carrier material during or after its preparation or to the catalytic composite before, during or after the incorporation of other components.

 An optional catalyst component that is particularly useful in embodiments of the hydrocarbon conversion of the present invention containing dehydrogenation, dehydrocyclization or hydrogenation reactions are alkaline or alkaline earth metal components. More specifically, this optional ingredient is selected from the group consisting of alkali metal compounds - cesium, rubidium, potassium, sodium and lithium - and earth-earth metal compounds - calcium, strontium, barium and magnesium. Typically, good results are obtained in those embodiments when the component is from 0.01 to 5% by weight of the composite, calculated on an elemental basis. These optional alkaline or alkaline earth metal components may be incorporated into the composite by any of the known methods, impregnation with an aqueous solution of a suitable water soluble, degradable compound is preferred.

As indicated above, it is necessary to use at least one oxidation step in the preparation of the catalyst. The conditions used to carry out the oxidation step are chosen so as to convert essentially all the metal components in the catalytic composite into their corresponding oxide form. The oxidation step is usually carried out at a temperature of from 370 ^° C. to 600 ^° C. The oxygen atmosphere used usually contains air. Typically, the oxidation step should be carried out in a period of from 0.5 to 10 hours or more, the exact time period being that required to convert essentially all of the metal components into their corresponding oxide form. This time will, of course, vary with the oxidation temperature used and the oxygen content in the atmosphere used.

In addition to the oxidation step, the halogen adjustment step can also be used in the manufacture of the catalyst. As indicated above, the halogen adjustment step may have a dual function. Firstly, the halogen adjustment step can help in the homogeneous dispersion of a Group IVA metal (UPAC 14) and other metal component. In addition, the halogen adjustment step may serve as a means of incorporating the desired level of halogen into the final catalyst composite. The halogen adjustment step uses a halogen or halogen-containing compound in air or an oxygen atmosphere. Since the preferred halogen for incorporation into the catalytic composite includes chlorine, the preferred halogen or halogen-containing compound used during the halogen adjustment step is chlorine, HCl or a precursor of these compounds. In the halogen adjustment step, the catalyst composite is contacted with the halogen or halogen-containing compound in air or in an oxygen atmosphere at an elevated temperature of from 370 ^° C to 600 ^° C. It is further desirable to have water present during the contacting step in order to facilitate regulation. In particular, when the halogen component of the catalyst contains chlorine, it is preferable to use a molar ratio of water to HCl of 5: 1 to 100: 1. The duration of the halogenation step is usually from 0.5 to 5 hours or more. Due to the similarity of conditions, the halogen adjustment step may take place during the oxidation step. Alternatively, the halogen adjustment step may be performed before or after the oxidation step, as required in the particular process used to prepare the catalyst in accordance with the invention. Regardless of the method used for fine adjustment of halogen, the halogen content of the final catalyst should be such that the halogen content, on an elemental basis, from 0.1 to 10% by weight of the final composite is sufficient.

In preparing the catalyst, it is also necessary to carry out the reduction step. The reduction step is intended to restore essentially the entire metal component of the platinum group to the corresponding elemental metallic state and to provide a relatively uniform and finely divided dispersion of this component in the refractory inorganic oxide. Preferably, the reduction step is carried out in a substantially water-free environment. Preferably, the reducing gas is essentially pure dry hydrogen (i.e., less than 20 ppmv water). However, other reducing gases such as CO, nitrogen, etc. can also be used. Typically, the reducing gas is contacted with the oxidized catalyst composite under conditions including a reduction temperature of from 315 ^° C. to 650 ^° C. for a period of from 0.5 to 10 or more hours, effective to recover substantially all of the platinum group metal component to an elemental metal condition. The reduction step may be performed prior to loading the catalytic composite into the hydrocarbon conversion zone, or may be performed in situ as part of the initial hydrocarbon conversion process. However, if the latter method is used, appropriate precautions must be taken to pre-dry the hydrocarbon conversion unit to a substantially water-free state and a substantially water-free hydrogen-containing reducing gas should be used.

 Optionally, the catalytic composite may be subjected to a preliminary sulfidation step. The optional sulfur component may be incorporated into the catalyst by any known method.

The catalyst of the present invention has practical applications as a hydrocarbon conversion catalyst. The hydrocarbon to be converted is contacted with the catalyst under hydrocarbon conversion conditions, which include a temperature of from 40 ^° C. to 300 ^° C., a pressure of 1 atmosphere to 200 atmospheres abs. (101.3 kPa to 20.26 MPa) and hourly volumetric fluid velocities from 0.1 to 100 h ^-1 . The catalyst is particularly suitable for catalytic reforming of gasoline feedstocks, and can also be used for dehydrocyclization, isomerization of aliphatic and aromatic compounds, dehydrogenation, hydrocracking, disproportionation, dealkylation, alkylation, transalkylation, oligomerization and other hydrocarbon conversions.

 In a preferred embodiment of the catalytic reforming, the hydrocarbon feed and the hydrogen rich gas are preheated and loaded into a reforming zone containing typically from two to five series reactors. Suitable heating means are located between the reactors to compensate for the total endothermic heat of the reactor in each of the reactors. The reactants can be contacted with the catalyst in individual reactors or when moving up, down or in the radial direction with a preferred radial flow regime. The catalyst is contained in a fixed bed system or, preferably, in a moving bed system with associated continuous catalyst regeneration. Alternative approaches to reactivating a deactivated catalyst are well known to those skilled in the art and include a semi-regenerative operation in which the entire plant is stopped for catalyst regeneration and reactivation, or operation with a swing reactor, in which a separate reactor is isolated from the system, regenerated and reactivated, while the rest the reactors remain in operation. A preferred continuous catalyst regeneration in conjunction with a moving bed system is disclosed, however, in US-A-3647680, US-A-3652231, US-A-3692496 and US-A-4832291, which are incorporated herein by reference.

The effluent from the reforming zone passes through a cooling means to a separation zone, usually maintained at a temperature of 0 ^{° C.} -65 ^{° C.} , in which the hydrogen rich gas is separated from the liquid stream, commonly referred to as the “unstabilized reforming product”. The resulting hydrogen stream can then be recycled through a suitable compression means back to the reforming zone. The liquid phase from the separation zone is usually removed and treated in a fractionation system in order to control the concentration of butane, whereby controlling the evaporation of the head fraction of the obtained reforming product.

The operating conditions used in the reforming method of the present invention include a pressure selected in the range from 100 kPa to 7 MPa (abs.). Particularly good results are obtained at low pressure, namely at a pressure of 350 to 2500 kPa (abs.). The reforming temperature is in the range from 315 ^° C. to 600 ^° C., preferably from 425 ^° C. to 565 ^° C. As is well known to those skilled in the art of reforming, the initial temperature selection from this wide range is carried out mainly as a function of the desired octane number the resulting reformate, considering the characteristics of the feedstock and catalyst. Typically, the temperature then rises slowly during operation to compensate for the inevitable deactivation that occurs to obtain a constant octane product. A sufficient amount of hydrogen is supplied to provide an amount of 1 to 20 moles of hydrogen per mole of hydrocarbon feed to the reforming zone, and excellent results are obtained when 2 to 10 moles of hydrogen per mole of hydrocarbon feed are used. Also, the hourly volumetric fluid velocity (LHSV) used in reforming is selected in the range from 0.1 to 10 h ⁻¹ , with a preferred value in the range from 1 to 5 h ⁻¹ .

The hydrocarbon feed that is charged to the reforming system is preferably a petroleum feed containing naphthenes and paraffins that boil in the gasoline range. The preferred feedstocks are gasoline-naphtha fractions, consisting mainly of naphthenes and paraffins, although aromatic compounds may also be present in many cases. This preferred class includes direct distillation gasoline, natural gasoline, synthetic gasoline, and the like. In an alternative embodiment, it is often advantageous to load thermally or catalytically cracked gasolines, partially reformed (improved) gasoline-naphtha fractions (naphtha) or dehydrogenated gasoline-naphtha fractions. Mixtures of direct distillation gasoline-naphtha fractions and cracked gasoline-naphtha fraction of the gasoline range can also be used. The feedstock of naphtha gasoline range can be gasoline with a boiling point of the entire gasoline range, having an initial ASTM D-86 boiling point of 40-80 ^o C and an end boiling point in the range from 160 to 220 ^o C, or can be its selected fraction , which will usually be a fraction with a higher boiling point, usually related to the so-called heavy naphtha - for example, naphtha, boiling in the range of 100-200 ^o C. If the reforming is aimed at obtaining one or more of benzene, toluene or xylene, then the boiling range may prefer ety or mostly be within 60-150 ^o C. In some cases it is also advantageous to load the pure hydrocarbons or hydrocarbon mixtures which are extracted from the extraction installation - for example, raffinates from aromatics extraction or straight-chain paraffins which can be converted into aromatics.

It is generally preferable to use the present invention essentially under anhydrous conditions. To achieve this condition in the reforming zone, it is essential to control the level of water present in the feedstock and in the hydrogen stream that is supplied to the zone. The best results are usually obtained when the total amount of water entering the conversion zone from any source is maintained at less than 50 ppm and preferably less than 20 ppm, expressed as the weight of equivalent water in the feed. In general, this can be done by carefully controlling the water present in the feed and in the hydrogen stream. The feed can be dried using any known suitable drying agent, such as a conventional solid adsorbent having high selectivity to water, for example sodium or calcium crystalline aluminosilicates, silica gel, activated alumina, molecular sieves, anhydrous calcium sulfate, sodium with a large surface area etc. adsorbents. Similarly, the water content of the feedstock can be controlled by suitable stripping operations in a fractionation column or the like. In some cases, a combination of drying the adsorbent and drying by distillation can be advantageously used to effect an almost complete removal of water from the feedstock. Preferably, the feed is dried to a level corresponding to less than 20 ppm H ₂ O in equivalent.

 Preferably, the water content of the hydrogen stream entering the hydrocarbon conversion zone is maintained at a level of from 10 to 20 ppm by volume or less. In cases where the water content in the hydrogen stream is above this limit, this can usually be accomplished by contacting the hydrogen stream with a suitable desiccant, such as those mentioned above, under normal drying conditions.

 Preferably, the present invention is used in a substantially sulfur-free environment. Any controls known in the art can be used to process the original naphtha, which should be loaded into the reforming reaction zone. For example, the feed stream may be subjected to adsorption processes, catalytic processes, or combinations thereof. Adsorption methods may use molecular sieves, alumina-silica with a large surface area, carbon molecular sieves, crystalline aluminosilicates, activated carbon, metal-containing compositions with a large surface area, such as nickel or copper, etc. It is preferable that this feedstock be processed by conventional pre-catalytic treatment methods, such as hydrotreating, hydrotreating, hydrodesulfurization, etc., to remove substantially all sulfur, nitrogen and water-producing contaminants from it and to saturate any olefins that may be contained in it. Catalytic processes can utilize conventional catalytic sulfur reduction methods known in the art, including refractory inorganic oxide supports containing metals selected from the group consisting of group VI-B (6), group II-B (12) and group VIII (IUPAC 8-10) Periodic table.

One embodiment according to the invention includes a process for converting the starting naphtha under catalytic dehydrocyclization conditions. In particular, a preferred starting naphtha contains C ₆ -C ₈ non-aromatic hydrocarbons. Dehydrocyclization conditions include a pressure of from 100 kPa to 4 MPa (abs.) With a preferred pressure of from 200 kPa to 1.5 MPa, temperature 350 ^o C to 650 ^o C and a liquid hourly space velocity from 0.1 to 10 per hour ^{- 1} . Preferably, hydrogen may be used as a diluent. When present, hydrogen can circulate at a rate of 0.2 to 10 moles of hydrogen per mole of the original hydrocarbon.

Preferably, the starting naphtha of an alternative embodiment of the dehydrocyclization process contains a large proportion of paraffins, since the purpose of the dehydrocyclization process is to convert paraffins to aromatics. Due to the high value of C ₆ -C ₈ aromatic compounds, it is further preferred that the starting naphtha contains C ₆ -C ₈ paraffins. However, despite this preference, the starting naphtha may contain naphthenes, aromatics, and olefins in addition to C ₆ -C ₈ paraffins.

EXAMPLE 1
The prior art spherical catalyst containing platinum and tin on alumina is prepared by conventional methods as a control catalyst for comparison with the catalysts of the present invention. Tin is introduced into the alumina sol in accordance with the prior art, and the tin-containing alumina sol is formed by dripping into the oil to form spheres of 1.6 mm, which are water vaporized to dryness at 10% LOI and calcined at 650 ^° C. The spherical support is then impregnated with platinum chloride acid in HCl of the day to obtain 0.38 wt.% Pt in the final catalyst. The impregnated catalyst is dried and oxychlorinated at 525 ^{° C.} with 2M HCl in air and reduced with pure hydrogen at 565 ^° C.

The final control is determined by Catalyst X, which has the following approximate composition, wt.%:
Platinum - 0.38
Tin - 0.3
EXAMPLE 2
A spherical catalyst containing platinum, ytterbium and tin on alumina is prepared to demonstrate the features of the invention. Tin is introduced into the alumina sol in accordance with the prior art and the tin-containing alumina sol is formed by dripping into the oil to form 1.6 mm spheres, which are water vaporized to dryness at 10% LOI and calcined at 650 ^° C. The spherical support is then impregnated ytterbium nitrate in 3.5% nitric acid to obtain 1.1% Yb in the final catalyst at a 1: 1 ratio of solution to carrier. The resulting composite was subjected to steam treatment to dryness (10% LOI) and calcined at 650 ^° C. with 3% steam. The resulting calcined composite is impregnated with platinum chloride in HCl to obtain 0.38 wt.% Pt in the final catalyst. The impregnated catalyst is dried and hydrochlorinated at 525 ^{° C.} with 2 M HCl in air and reduced with pure hydrogen at 565 ^° C. The final Yb-containing catalyst is defined as Catalyst A and has the following approximate composition, wt.%:
Ytterbium - 1.1
Platinum - 0.38
Tin - 0.3
Other catalysts containing lanthanum, samarium and dysprosium are prepared in the same manner as the ytterbium-containing catalyst. The lanthanide content in the final catalysts was as follows, with each catalyst having substantially the same tin and platinum content as Catalyst A:
Catalyst B - 0.9 wt.% La
Catalyst C - 1.0 wt.% Sm
Catalyst D - 1.1 wt.% Dy
EXAMPLE 3
Tests in an experimental setup were structured to compare aromatic selectivity during reforming of the catalysts of the invention and known. The tests are based on reforming naphtha over catalysts at a pressure of 0.8 MPa (abs.), A liquid hourly space velocity of 3 h ^-1 and a hydrogen / hydrocarbon molar ratio of 8. The conversion range is studied by changing the temperature to obtain data at points at 502 ^o С, 512 ^o С, 522 ^o С and 532 ^o С. Naphtha for comparative tests is hydrotreated obtained from naphtha oil, obtained from paraffin crude oil products from the middle of the continent, which has the following characteristics:
Specific Gravity - 0.737
Distillation, ASTM D-86, ^o C IBP - 87
10% - 97
50% - 116
90% - 140
EP - 159
wt.% paraffins - 60
naphthenes - 27
aromatic compounds - 13
The results are shown as the dependence of the yield of aromatic compounds on the yield of C ₅ ⁺ in FIG. 1 for catalysts A, B, C, D and X. The yield of aromatic compounds is defined as the yield in wt.% (Benzene + toluene + aromatic compounds C ₅ ⁺ aromatic Compounds C ₉ ). Since a high yield of aromatic compounds is usually an essential goal of catalytic reforming, a high yield of aromatic compounds with respect to the yield of C ₅ ⁺ is an indicator of high selectivity. Catalysts A, B, C and D according to the invention show a yield of aromatic compounds 2-3% higher at the same yield of C ₅ ⁺ .

EXAMPLE 4
Tests in the experimental setup were structured to compare the selectivity and activity of catalysts C and X of the reforming day of the initial naphtha. The naphtha of the day of comparative tests is taken the same as in example 3. Each test is based on reforming conditions containing a pressure of 0.8 MPa (abs.), Hourly volumetric flow rate of the liquid is 3 hours ^-1 and the hydrogen / hydrocarbon ratio is 8. Range conversions are studied by changing the temperature to obtain several data at points at 502 ^° C, 512 ^° C, 522 ^° C and 532 ^° C. The conversion (paraffins + naphthenes) at each temperature was 2-4% higher for catalyst X, but selectivity as the yield of C ₅ ⁺ product was higher in the entire conversion range for catalyst C. Graph the dependence of selectivity on conversion is depicted in figure 2.

EXAMPLE 5
Three spherical catalysts containing platinum, europium and tin on alumina are prepared to demonstrate the features of the invention. Tin is introduced into the spherical support alumina in accordance with the prior art, as described in Example 2. The spherical support is then impregnated with europium nitrate in 3.5% nitric acid to obtain three different levels of Eu in the final catalyst at a 1: 1 ratio of solution to support. . The resulting composites are subjected to steam treatment to dryness (10% LOI) and calcined at 650 ^° C. with 3% steam. The resulting calcined composites are impregnated with platinum hydrochloric acid in HCl to obtain 0.38 wt. % Pt in the final catalyst. The impregnated catalysts are dried and oxychlorinated at 525 ^° C. with 2 M HCl in air and reduced with pure hydrogen at 565 ^° C. The final Eu-containing catalysts are defined as catalysts E, F and G and have the following approximate composition in wt.%, Shown in table 1 .

EXAMPLE 6
Catalyst G is tested in comparison with the prior art catalyst X to determine the presence of EuO according to reduction. The recovery programmable temperature is carried out using 5 mol. % H ₂ in Ar with increasing temperature from room temperature to 600 ^o C at a rate of 10 ^o C per minute. The hydrogen consumption for catalyst G is higher than for catalyst X by 33 μmol / g, indicating a reduction of more than 90% Eu ⁺³ in Eu ⁺² .

EXAMPLE 7
Tests in the experimental setup were structured to compare the selectivity and activity of catalysts E, F, and G with the selectivity and activity of catalyst X for reforming the starting naphtha. Naphtha for comparative tests is taken the same as in example 3.

Each test is based on reforming conditions containing a pressure of 0.8 MPa (abs.), Hourly volumetric fluid velocity of 3 h ^-1 and a hydrogen / carbon ratio of 8. The conversion range is studied by changing the temperature to obtain several data at points at 502 ^o C, 512 ^o C, 522 ^o C and 532 ^o C. Comparative conversion (paraffins + naphthenes), the yield of the product C ₅ ⁺ and the yield of aromatic compounds are expressed in wt.% in table 2.

Figure 3 depicts a graph of the yield of aromatic compounds depending on the yield of C ₅ ⁺ , based on the above values, showing a higher yield of aromatic compounds at the same outputs of C ₅ ⁺ for the catalysts according to the invention.

The ratios of activity and selectivity were obtained from the above values and are shown in figure 4. Activity was calculated as% reduction in conversion from base catalyst X for each temperature and plotted against the atomic ratio Eu / Pt for the respective catalysts. The selectivity is obtained from FIG. 3 by measuring the change in the yields of aromatic compounds between the catalysts over the entire range of C ₅ ⁺ outputs and is divided into C ₅ ⁺ output, i.e. the average Δ yield of aromatic compounds, expressed as% yield of C ₅ ⁺ . When displayed on a graph of the latter in FIG. 4, the extension of the line to the higher Eu / Pt ratio of catalyst G is depicted by a thinner line, since there is only a slight overlap of the line for catalyst G with lines of other catalysts in FIG.

 4 depicts an accelerating decrease in conversion with an increase in the europium content in the catalyst when the ratio with Eu / Pt increases from 1 to 2, and the slope becomes even greater for a ratio greater than 2. The ratio of selectivity to Eu / Pt, on the other hand, is more linear. Although the choice of the Eu / Pt ratio will depend on the relative importance of selectivity and activity, very high ratios will be accompanied by a large decrease in activity in relation to the benefit in selectivity.

Claims (5)

1. A hydrocarbon conversion catalyst containing a metal component of the platinum group, a metal component of the IVA group, halogen, a metal component of the lanthanide group, where a part of the lanthanide is present in the form of an oxide, and the carrier is a refractory inorganic oxide, characterized in that the catalyst contains lanthanide as a metal europium, and the atomic ratio of europium to the metal of the platinum group is at least 1: 3, where more than 50% of europium is present as EuO, in the following ratio of components wt. %:
Platinum group metal - 0.01-2.0
Group IVA metal - 0.01-5.0
Halogen - 0.1-10
Europium - 0.05-5.0
Media - Other
2. The catalyst according to claim 1, characterized in that as a refractory inorganic oxide contains aluminum oxide.  3. The catalyst according to paragraphs. 1 and 2, characterized in that as the metal of the platinum group contains platinum.  4. The catalyst according to claims. 1-3, characterized in that the metal of group IVA contains tin.  5. The catalyst according to paragraphs. 1-4, characterized in that as a halogen contains chlorine. 6. The method of catalytic reforming of the initial naphtha, including contacting the feed under reforming conditions: temperature 425-565 ^o C, pressure 350-2500 kPa, hourly space velocity of the liquid 1-5 h ^-1 and the molar ratio of hydrogen to the supplied hydrocarbon 2-10 in the presence of catalyst, characterized in that the catalyst used is the catalyst according to any one of claims 1 to 5.

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