Acidic multimetallic catalytic composite and use thereof in hydrocarbon conversion

The subject of the invention is a new multi-metal acid catalyst for the conversion of hydrocarbons with extremely high activity and resistance to deactivation, showing the activity of hydrogenation-dehydration and the activity of creating carbonate ions. More particularly, the invention relates to a novel multi-metal acid catalyst which surprisingly improves hydrocarbon conversion processes for which a dual action catalyst is traditionally used. IN. the composition of the new catalyst includes platinum group metals, cobalt and tin, and a halogen component applied to a porous substrate.

Catalysts for hydrogenation-dehydration and carbonium ion formation are widely used in many industries, such as crude oil refining and the petrochemical industry, to accelerate a variety of hydrocarbon conversion reactions. Generally, the activity of creating carbonate ions is attributed to the acidic properties of the porous, adsorptive, hardly melting oxides used as a support for metals or metal compounds of groups V-VIII · of the periodic table of elements, which are attributed hydrogenation-dehydration properties.

Taffeta catalytic preparations are used to accelerate various hydrocarbon conversion reactions, such as hydrocracking, hydrogenolysis, isomerization, dehydrogenation, hydrogenation, desulfurization, cyclization, polymerization, alkylation, cracking, hydroisomerization, dealkylation, transalkylation, etc. In many cases, catalysts are used in processes such as more than one of the above reactions occur simultaneously. An example of a process of this type is reforming, in which a mixture of paraffinic and naphthenic hydrocarbons is subjected to conditions that promote the dehydrogenation of naphthenes to aromatics, isomerization of naphthenes and paraffins, hydrocracking and hydrogenolysis of naphthenes and paraffins, and similar reactions to give the product octane-rich or aromatic-rich. .

Another example is the hydrocracking process, in which catalysts of the above type are used to selectively hydrogenate and crack unsaturated high molecular weight compounds and induce other similar reactions.

so leading to a more valuable product. with a lower molecular weight. Another example is the hydroisomerization process, in which a hydrocarbon fraction with a relatively high content of straight-mouth paraffinic hydrocarbons is contacted with a dual-action catalyst to obtain a product rich in isoparaffinic compounds.

Regardless of what reaction takes place in the process to be catalyzed, it is essential that the dual function catalyst is not. it only showed the ability to 90 322

322 capacity to fulfill his task, but to fulfill it satisfactorily and over a long period of time. Analytical terms used to describe how a particular catalyst performs its intended purpose under the conditions of a specific reaction are: activity,. selectivity and durability. For the purposes of this description, the terms are defined as follows:

(1) activity is a measure of a catalyst's ability to convert a hydrocarbon substrate into a product under certain conditions such as temperature, pressure, contact time, and the presence of diluents such as H2. (2) selectivity is the ratio of the desired product or products obtained to the amount of sub - · otter - introduced or converted, (3) ^ durability determines · the rate of change in time of activity and selectivity - of course, the slower the rate of change / the more durable the catalyst. For example, in the reforming process, activity determines attractiveness ^J.Stop^ande^ń conversion spec^lthey^go charge under specified conditions, typically measured _aothe octane number of the C5- fraction in the product, the selectivity determines the yield of the C fraction₅- + from the charge obtained 'at a given level of activity, and the durability · is usually expressed as the rate of changes in activity time, measured by the octane number ₂₅the C5 + product and selectivity as measured by the yield of the C5 + fraction. In fact, the latter statement is not strictly correct as the continuous reforming process is generally carried out in such a way as to obtain a product with a constant_S0the octane number of the C5 + fraction by continuously changing the process conditions. Moreover, the conversion temperature in the reaction zone is chosen such that the rate of change in activity responds to the rate of change in temperature.₃₅conversion turns, and changes in this parameter are usually taken as a measure of the persistence of the activity.

As is known, the main cause of the observed deactivation or instability of the dual-action catalyst. the hydrocarbon conversion reaction causes deposition thereon during the course of the reaction of coke. More specifically, under the conditions of typical hydrocarbon conversion processes, a heavy, high molecular weight, black, solid or semi-solid carbon material is produced, which is a hydrogen-deficient polymeric substance with properties similar to those of both polycyclic aromatic compounds and graphite. This material covers the surface of the catalyst and reduces its activity, shielding the active centers from the access of reagents. In other words, the properties of such a double-tail catalyst are sensitive to the presence of carbonaceous deposits or coke on its surface. Accordingly, the main problem to be solved in this field is the development of a 'more active and / or more selective catalyst, less sensitive to the presence of carbonaceous substances. sediments and / or having the ability to reduce the rate of deposition of these sediments on ⁸⁰Catalyst .. In terms of performance parameters, the task comes down to developing a bifunctional catalyst with enhanced activity, selectivity and durability. In the case of the reforming process, this means a shift of the assumed assumption. the ratio of the yield of the C5 + fraction to the octane number to the lowest possible values ​​of the reaction parameters (temperature, pressure, contact time, irbp.) and fixing it at these values. (The yield of the C5 + fraction is a measure of selectivity and the octane number is proportional to the activity of the catalyst.)

The subject of the invention is a difunctional acid multi-metal catalyst with increased activity, selectivity and durability in the hydrocarbon conversion process of the type used so far. , hydrodealkylation, transalkylation, cyclization, dehydration cyclization, cracking, hydrocracking, halogenation, reforming and similar processes. It has been found that an acidic catalyst containing a mixture of catalytically effective amounts of platinum group metals, cobalt, tin and halogen significantly improves the hydrocarbon conversion process carried out with the use of bifunctional catalysts, if the metal components are evenly distributed in the support and if their oxidation degree is in the manner controlled maintained at the level given below. In addition, it has been found that an acid catalyst containing a mixture of catalytically effective amounts of platinum group metal, tin, cobalt and chloride, deposited on alumina, significantly increases the reforming efficiency of miscoctam gasoline to a high-octane product if the metallic components are evenly distributed in the support, if the average size of the crystallites or particles of the tin and cobalt components is largely less than 100 agstroms and if the oxidation state of the metallic components is maintained at the level given above. In the case of the reforming process, the main benefit of using the catalyst according to the invention is its operability. constant parameter values, e.g. in low- or mid-pine tree reforming, yielding a reformed · C5 + product with an octane number of around 100.

The essence. The invention relates to the addition of tin and cobalt to a platinum group metal-containing dibactic acid hydrocarbon conversion catalyst, which significantly improves the properties of the catalyst, provided that the quantitative content of the components, the size of the crystallites or the particles of the compounds are met. tin and cobalt, metal oxidation state and distribution, metal components in the support.

The acid catalyst according to the invention in a porous support contains, based on the element, (* -1-2% by weight of platinum group metal, 0.5-5% by weight of cobalt, 0, <1-5% by weight of tin and 0.1- 3.5% by weight of halogen, the platinum group metal tin and cobalt are evenly distributed in the porous support, substantially all of the platinum group metal is in elemental form, and all the tin is in an oxidation state above the elemental state, and cobalt is substantially all metallic, or a state from which reducible to metallic state under hydrocarbon conversion conditions.

Preferably, the catalyst contains 0.0-5-1% by weight of platinum, 0.5-2% by weight of cobalt, 0.05-1% by weight of tin and 0.5-1.5% by weight of halogen.

Profitable _T.catalysis carrier material. tora is a porous sorbent with an area of ​​25-500 m²/ g. The porous support should be infusible under the conditions of the hydrocarbon conversion process. Suitable materials are, inter alia, those conventionally used in the preparation of dual-grade hydrocarbon conversion catalysts such as activated carbon, coke or water. wood, silica or silica gel, silicon carbide, clays and silicates, synthetic or natural water, possibly acid treated, such as attapulgite clay, kaolin, diatomaceous earth, Fuller earth, silica etc., ceramics, porcelain, crushed brick, bauxite, refractory inorganic oxides, such as aluminum oxide, titanium dioxide, chromium oxide, beryllium oxide, vanadium oxide, celadium oxide, hafnium oxide, zinc oxide, magnesium oxide, boron oxide, thorium oxide, mixtures of silica with aluminum oxide, silicas with magnesium oxide, 'chromium oxide' with aluminum oxide, aluminum oxide with boron oxide, silicas with zirconium oxide, etc., crystalline zeolite aluminosilicates, natural or synthetic, planted with hydrogen ions or qualitative cations, spinels like. MigAl? O₄, FeAlOOi, ZnAl2, Mi4Al2, CaAl2C4 and other similar compounds of the formula MO · Al2O3 where M is a divalent metal, and mixtures of materials from one or more of the above groups.

The preferred porous support materials for use in the present invention are the slow-burning inorganic oxides, and the best results are obtained with aluminum oxide as the support. Suitable alumina materials are the crystalline materials known as yA ^ Cb, η-AlaOj, and v-A1₂ABOUT₃, except that the use of 7-Al2O3 or j-AlaO gives the best results₃. In some cases, in addition to alumina, the carrier may contain minor amounts of other known refractory non-organic oxides such as silica, zirconium dioxide, magnesium oxide and the like, with the preferred carrier being substantially pure y- or j-AlOj. The preferred support material has a bulk density of 0.3-0.8 g / m 2, an average pore diameter of 20-300 acres, a pore volume of 0.1-1 cc / g, and a specific surface area of ​​100-500 mt / g. In general, the best results are obtained when the carrier is y-AjO3 in the form of spherical particles with a relatively small diameter (typically, about 1/6 cm), a bulk density of 0.001), 8 g / cm®, a pore volume of about 0.4 em® / g and a specific surface area of ​​about 200 m2? g.

One of the essential components of the acidic polymetallic catalyst according to the invention is tin, and it is important that it is substantially completely in the higher oxidation state. ⁰⁶

W 322 from elemental tan. in the +2 or +4 oxidation state. Thus, the tin may have the form of a chemical compound in the catalyst such as an oxide, a halide, an oxyhalide, etc. in which the tin is⁵ in a positively oxidized state or in a chemical combination with the support material in such a way that the tin is in a positively oxidized state. Attempts at the controlled reduction of the catalyst prepared with the preferred variant showed that¹⁰ the tin is in a positive oxidation state in these catalysts and that it is not reduced when it comes into contact with hydrogen at a temperature of 538-649 ° C. The above limitations on the degree of tin oxidation require great care in the manufacture¹⁹ the use and use of the tin compound, and in particular to ensure that it is not exposed to a reducing atmosphere at temperatures above 649 ° C. Equally important is the observation that the tin component has the ability to persist in²⁰ in the positive oxidation state in the further described pre-reduction step, when uniformly distributed in the carrier. 'Expressing it otherwise, if the' tin component is not properly distributed 'in the carrier, it may be subject to²⁹ reduction in the pre-reduction step, which deteriorates the quality of the catalyst. The data obtained so far show that the catalyst has the best properties when the tin is present in the form of an oxide. The term "tin oxide" as used herein²⁰ of the present specification refers to the tin-oxygen coordination complex in which the ratio of tin atoms to oxygen atoms need not be stoichiometric.

With restrictions on the oxidation state ²⁹ the distribution of the tin component in the carrier and its particle size are related. Only then is the tin component found to maintain a favorable oxidation state at the high temperature of the 'pre-reduction & lt; 0 & gt; or hydrocarbon conversion step when uniformly distributed in a particulate or crystallite carrier with a maximum size of less than 100 angstroms. Thus, an essential feature of the invention is that the acidic multi-metal catalyst is obtained in such a way as to meet the requirements regarding the particle size and distribution. When we say that a certain component is evenly distributed in the carrier it is meant that the concentration of that component in any separable portion of the carrier is approximately constant. The expression, "particles or crystallites with a maximum size of less than 100 angstroms, means that the particles would pass through a 100 angstrom mesh screen. ⁹⁹ if such a screening was feasible. The tin component may be. incorporated into the catalyst by any suitable method that results in an effective distribution of the component in the carrier in the form of particles of the desired size.

₀0 Thus, this component can be 'incorporated into the support by co-precipitation or joint gelation of the appropriate soluble' tin salt and support, by exchanging the support ions for tin ions, if the ion exchange centers are uniformly distributed in the support.

V

322 or by impregnating the support with a suitable soluble tin salt under conditions ensuring that the component is evenly distributed throughout the support material.

One preferred method of introducing the tin component is by co-precipitation. it · or gelation with the preferred catalyst support alumina. In this process, a suitable soluble tin compound, such as stannous chloride, tin gub is added to the alumina hydrosol, these components are mixed to evenly distribute the tin component in the sol, and then the hydrosol is mixed with a suitable gelling agent and the resulting mixture is dropped into the oil bath. After drying and calcining the gelled support, alumina is obtained, intimately mixed with tin oxide, with the required dispersion and particle size.

Another preferred method of introducing the tin component into the catalyst is by impregnation. (porous support material with a soluble decomposable tin compound. Suitable tin compounds for this purpose are stannous bromide, circus chloride, tin chloride, stannous chloride pentahydrate, tin trichlorobromide, tinchromate, stannous fluoride, tin fluoride, stannous iodide, tin sulfate and tin tartrate. The solvent used in impregnation is selected based on its ability to dissolve the desired tin compound and keep it in solution for a time sufficient to uniformly distribute it throughout the carrier, preferably an aqueous strong acid solution. Suitable inorganic acids are hydrochloric, nitric and the like, and suitable organic acids are oxalic, malonic, citric, maleic, formic and tartaric. The incorporation of the tin component into the support can be done prior to, jointly or after the introduction of the metal components. It is excellent to incorporate the tin component into the carrier during preparation of this. the support and the remaining metallic components by impregnating the expressed tin-containing support.

The second essential component of the catalyst according to the invention is a metal of the platinum group. The metal can be platinum, iridium, osmium, tutene, rhodium, palladium or mixtures of these elements. An essential feature of the catalyst according to the invention is that the platinum group metal is present in it in the elemental form.

The platinum group metal may be introduced into the catalyst by any suitable method known in the art to distribute the platinum group metal relatively evenly throughout the support. Suitable methods are co-precipitation or co-gelation, ion exchange, or ipmregnation. The preferred way is. on the impregnation of the carrier - * with a soluble, decomposable salt of a platinum group metal. For example, this component eo can be introduced into the catalyst by mixing the carrier⁷nok with an aqueous' solution of chloroplotinic, chloriridic or chloropalladic acid or rhodium trichloride.

The third essential component of the present invention's multi-metal acid catalyst is cobalt. This component can be introduced into the catalyst in various decomposable forms, however, it has been found that the catalytically active state of this component is the elemental state. It is a feature of the catalyst according to the invention that cobalt is present essentially completely in the elemental state or in the form of a compound which is reduced to element under the conditions of conversion of hydrocarbons. Examples of suitable reducible forms are the oxide, halide and oxyhalide. To obtain the full benefits of the present invention, the incorporation of cobalt into the catalyst in forms which are not reducible under the conditions of hydrocarbon conversion should be scrupulously avoided. Examples of undesirable forms of cobalt are. sulphides and oxosulfur compounds such as cobalt sulphate. Best results are obtained when cobalt; it is present in the catalyst initially in metallic form, as a reducible oxide, or in a mixture of both. A preferred catalyst is described in Example 1, in which the cobalt is in the form of a reducible oxide.

Cobalt may be introduced into the catalyst by any suitable method which results in a relatively uniform distribution of this component in the support. Suitable methods are combined precipitation, combined gelling, ion exchange, impregnation, etc. The inclusion of the cobalt component may be done in any state of catalyst preparation, during the preparation of the support or during the preparation of the support. further operations as the method of introduction is not critical. A catalyst has the best properties when cobalt is uniformly distributed therein in the form of particles or crystallites with a maximum size of less than 100 angstroms. One way to introduce cobalt is co-gelation or co-precipitation with alumina in the carrier preparation step. In this process, a soluble and decomposable cobalt compound such as chloride or nitrate is added to the alumina hydrosol. The resulting mixture is subjected to conventional treatment including gelling, maturing, drying and roasting.

A preferred method of introducing cobalt is to impregnate the porous support with a suitable cobalt compound solution before, during or after calcining or oxidizing the support. The cobalt compound solvent may be water, alcohol, ether, or any other suitable organic or inorganic solvent that does not react with the other components of the catalyst and does not hinder the distribution and reduction of the cobalt component. Usually, impregnation with an aqueous solution of cobalt chloride or nitrate gives the best results. The cobalt component can be added to the carrier before, simultaneously with, or after the addition. metallic components. A good method is to incorporate the cobalt component together with the platinum group metals in an acidic impregnation solution, and excellent results are obtained with an acidic aqueous solution containing chloroplatinic acid, cobalt chloride and hydrochloric acid.

It is essential to introduce a halogen into the multi-metal acid catalyst according to the invention. It is not entirely clear in what form the halogen is present in the catalyst. It is usually assumed to be in the form of an ion, e.g. chloride, bound to a support or other components of the catalyst. The halogen can be fluorine, chlorine, iodine, bromine or mixtures thereof. Fluorine and chlorine are particularly preferred for the purposes of the invention. Halogen may be added to the carrier by any suitable means, during the preparation of the carrier or before or after the addition of the other ingredients. For example, the halogen may be introduced in the carrier preparation step or into the calcinated carrier in the form of a water solution of a decomposing halogen compound such as hydrogen fluoride, hydrogen chloride, hydrogen bromide, rnon chloride and the like. The halogen component or part thereof may be combined with the support during impregnation of the support with platinum group metal compounds, cobalt or tin. For example, by using a mixture of chloroplatinic acid and hydrogen chloride. Otherwise, the alumina hydrosol from which the carrier is prepared may contain halogen and hence may be derived, at least in part, from halogen contained in the final catalyst preparation.

The preferred content of cobalt and tin in the catalyst is a function of the platinum group metal content. The cobalt content is usually selected so that the molar ratio of cobalt to platinum group metal is in the range 0.8-1 to 66: 1, preferably 1.6: 1 to 18: 1. The molar ratio of tin to platinum group metal should be 0.1: 1 to 13: 1, preferably 0.3: 1 to 5: 1.

Another important parameter of the catalyst according to the invention is the total amount of metals, i.e. platinum group metal, cobalt and tin, calculated as. elements. A good catalyst is one in which the value of this parameter is kept in the range of 0.15-4 wt%, and the best results are obtained with the use of a catalyst containing 0.3-3 wt% metals.

An optional component of the multi-metal catalyst of the invention is a metal halide used in Friedei-Orafts reactions. This component is particularly useful in those cases of hydrocarbon conversion where it is desired that the catalyst used has strong acid properties and strong cracking activity, for example in hydrocracking or isomerization processes. Suitable type • metal halides for use in Eriedel-Crafts reactions include • aluminum chloride, aluminum bromide, ferric chloride, ferric bromide, zinc chloride, and the like. The use of aluminum halides gives the best results, especially. aluminum chloride. This optional component may be introduced into the catalyst according to the invention by any conventional method of introducing halides. of this type. The best results are obtained when subliming onto the surface of a carrier as set forth in US Patent No.

999 074. The said component is incorporated into the catalyst in any catalytically effective amount, preferably in an amount of 1 to 100% by weight of the carrier.

⁵ Regardless of the details of the incorporation of the catalyst components into the porous support, the final formulation is typically dried at 93-316 ° C for 2-24 hours and then calcined or oxidized at 371-593 ° C.

¹⁰ air or oxygen, within 0.5-10 hours, in order to convert substantially all metallic components to the corresponding oxides. Since the catalyst contains a halogen component, the best results are obtained with its content¹⁵ is brought to the desired value in an oxidation step by supplying a halogen compound like HCl in air or oxygen. If the halogen component is chlorine, it is preferable to maintain it at least in part of the oxidation step²⁰ reducing the molar ratio of H 2 O to HCl in the range of 5: 1 to 100: 1 to bring the final chlorine content of the catalyst to 0.1-33.5 wt%. The halogenation is preferably carried out for 1-5 hours.

²⁵ Before using the oxidized catalyst in the hydrocarbon conversion process, it is preferable to pre-reduce it in an atmosphere free of water and hydrocarbons. In this treatment, a selective reduction of metals from the pla group takes place³⁰ to the elemental state with an even distribution of the metal in the support material, while maintaining the tin in a positive oxidation state. As reducing agent, it is preferable to use pure and dry hydrogen (o.

⁹⁵ contents of less than 20 · 10⁶ H2O parts by volume). The oxidized catalyst is contacted with the reducing agent at a temperature of 427-

649 ° C for 0.5-10 hours, which effectively reduces the platinum group metal compound to the constant⁴⁵ elemental nu, leaving the tin in an oxidation state. It has surprisingly been found that the reduction takes place in the hydrocarbon-free hydrogen at the stated temperature, and if the cobalt is suitably distributed in the carrier as an oxide of the given particle size, this component is substantially not reduced. On the other hand, a mixture of hydrogen and hydrocarbon quickly - reduces the cobalt component in the given temperature range. Reduction treatment may be carried out after the introduction of the catalyst into the hydrocarbon converter, if any. appropriate measures are taken to dry the equipment · and to protect · hydrogen against the ingress of water and hydrocarbons.

The resulting reduced catalyst is preferably kept in a sulfur-free state both in the production and use in hydrocarbon conversion steps.

The hydrocarbon-hydrogen mixture is contacted with the acidic multi-metal catalyst in the hydrocarbon conversion zone. The contacting can be carried out in a fixed catalyst bed, in a moving bed, or in a fluidized bed, or. batch operation system. To reduce the risk of loss of valuable catalyst due to abrasion and to obtain aaanyeh ko

322 For operational advantages, it is preferred to use a fixed or dense phase moving bed system as described in US Patent No. 3,725,249.

When the acid multimetallic catalyst of the invention is used in a reforming process, it is preferred that the reformed material consists essentially of naphthenes and paraffins, although aromatics and / or olefins are acceptable in some cases. Gasolines of natural and synthetic origin are the preferred raw materials. It is often advantageous to work up thermally or catalytically grated staines or their higher boiling fractions. Refor also gives good results. ming of mixtures of distillate and grid gasoline. The reformer feedstock may be gasoline with a full boiling range from an initial 10-66 ° C to a final 163-220 ° C or a high boiling fraction, usually called heavy naphthenic, boiling from the characteristic of C7 to 204 ° C.

Other conventional feedstocks can also be converted using the catalyst according to the invention. For example, in a typical isomerization process, the feedstock may be C4 to Cg-rich straight-chain paraffins, n-butane-rich fraction, n-hexane-rich fraction, xylene isomeric mixture, etc. In the hydrogenation process, the feedstock may be any of the dehydrogenating hydrocarbons, such as an aliphatic compound with 2 to 30 carbon atoms, C4-C30 normal paraffin, alkyl aromatic compound'C8-C_n, a naphthenic compound, etc. For hydrocracking, the feedstock is typically gas oil, heavy grating oil, and the like. The catalyst of the invention can also be used for the isomerization of alkoxylates and naphthenics. With the use of a catalyst. according to the invention, it is possible to convert pure or nearly pure hydrocarbons into more valuable products by any known hydrocarbon conversion process using a dual function catalyst.

The best results for the conversion of hydrocarbons with the multi-metal acid catalyst * of the invention are obtained when this catalyst is used in a substantially sulfur-free environment. Exposure "substantially sulfur-free environment" means that the total amount of sulfur and its compounds, capable of forming metal sulfides in the reaction conditions, is kept at a level lower than 10, preferably lower than 5, and most preferably lower than than in the reactants entering the reaction zone. 1 part by weight per million (as elemental sulfur).

. In the case of sulfur content in the feeding stream higher than. given, it is necessary * to undergo refinancing procedures. This is dictated by a catalytic pre-treatment in a hydrogen atmosphere which removes substantially all sulfur, nitrogen and water-forming contaminants. Machining usually. is carried out by contacting sulfurized hydrocarbons with an appropriate sulfur-resistant hydrogen refining catalyst in the presence of hydrogen, under conditions selected so that sulfur impurities are converted into hydrogen sulfide.

In the reforming process, it is preferable to use the novel multimetal acid catalyst according to the invention in a substantially anhydrous environment. To achieve these conditions in the reforming zone it is important to control the water level in the hydrocarbon and hydrogen stream entering the reaction zone. The best results * are usually achieved when the total water content of the feed stream is less than 26, preferably less than 5 parts by weight per million parts of stream. In general, this condition can be met by careful control of the water content of the hydrocarbon and hydrogen stream. Raw materials may be dried by any known method such as by the use of a conventional solid adsorbent with high selectivity for water, e.g., crystalline sodium or calcium aluminosilicate, silica gel, activated alumina, molecular sieves, anhydrous calcium sulfate, high surface area sodium, etc. The water value of the hydrocarbons can also be adjusted by stripping in a distillation column or the like. In some cases, it may be advantageous to employ a combination of adsorbent drying and distillation drying to remove the water almost completely from the hydrocarbons.

In a particularly preferred operating embodiment, the feed stream is dried to less than 5 parts by weight of water equivalent per million parts of stream. It is generally preferred to keep the water content of the hydrogen stream entering the conversion zone at 10 or less, and even more preferably about 5 or less. parts by volume per million parts of hydrogen. If the water content in the stream. . hydrogen is too high, it should be drained by passing it through a suitable dehydrating agent as mentioned above. .

In the reforming process, the product stream withdrawn from the reaction zone is passed through cooling devices to a separation stage, typically maintained at a temperature of -4 to 66 ° C, as hydrogen-rich gas is separated from the high-octane liquid liquid stream. If the water level in the Hydrogen stream is higher than the limit value specified above, the water-rich gas is carried away from the separation zone by at least part of the hydrogen-rich gas and pf ^ Z ^^ through the adsorption zone. contains a selective adSolbent for water. The leachate stream of Hydrate, which is essentially led to water, can be recirculated by a suitable correspon sive device down to the refor.riyirigU stage. The liquid phase is physically drained. from the separation zone and is treated in a fractionating system to achieve the desired concentration of butdrin, and the initial and final volatility of the reformate obtained is controlled.

The conditions used in the various conversion processes of the invention are the conditions typically employed for such reactions or combinations of reactions. For example, the isomerization of alkyl aromatic and paraffinic hydrocarbons is carried out at a temperature of 0-538 ° C, pressure ranging from atmospheric to 100 atm, with a hydrogen to hydrocarbon molar ratio of 0.5: 1-20: 1 and an hourly liquid space velocity (BHSV) , 2-10 hours^-1. The dehydrogenation is carried out at a temperature of 371-677 ° C and a pressure of 0.1-10 atm. and LHSV 1-40 hours-¹,. with a md ratio of hydrogen to · hydrocarbon of 1: 1—20: 1. The hydrocracking conditions are as follows: pressure 35-205 atm, temperature 204-482 ° C, LHSV 0.1-10 h-1, hydrogen to feed ratio 178-1780 vol. .

Pressures from 1 to 69 atm are used in the reforming process according to the invention. Especially good results are obtained at low or moderate pressures, namely 7.8-31.5 atm. A particular advantage of using the invention is that it allows stable operation at lower pressures than those hitherto used in tszw. "Continuous" reforming. (reforming without regeneration 4.5-65 m³ hydrocarbons per kg of catalytic converter) on a monomembrane platinum catalyst. In other words, the multi-metal acid catalyst according to the invention enables continuous reforming at lower pressures (7.8-31.5 atmospheres) with the same or longer catalyst life (interregeneration period) as obtained with conventional monometallic catalysts at higher pressures (28-42). atmosphere). The particularly high activity and stability of the activity of the catalyst according to the invention increase the interregeneration period when the process is operated at a pressure of 28-42 atmospheres.

By using the catalyst according to the invention, it is possible to carry out the reforming at a temperature much lower than that required in operations with the prior art catalysts. high-quality. This important and desirable feature of the invention is a consequence of the unique activity of the acid poly metal catalyst in octa-increasing reactions, which are preferably carried out in a conventional reforming operation. When using the catalyst according to the invention, a temperature of 427-593, preferably 482-566 ° C, is used. As is known, in the continuous feforming process, the choice of the initial temperature depends mainly on the desired octane number of the reformed product and on the characteristics of the substrate and catalyst. Typically, the temperature is slowly increased during the process to compensate for the inevitable deactivation of the catalyst and to keep the product octane number constant. The purpose of the invention is. not only a significant reduction in the initial temperature of reforming, but also a significant reduction in its growth rate to keep the octane value of the product constant, compared to these parameters in an equivalent operation using a high-quality reforming catalyst prepared as the catalyst of the invention, but without the addition of cobalt - and tin. Moreover, when using the catalyst according to the invention, the yield of fraction C will decrease₅ for a given

322 the temperature rise is much lower than when using - a high-quality reforming catalyst of the current composition.^>

The unique activity of the catalyst according to the invention can be used in a number of ways to increase the efficiency of catalytic reforming over that achieved in similar operations with the prior art mono or double metal catalysts. The possibilities offered by the new catalyst include: increasing the octane number of the product without significantly shortening the interregeneration period, significantly extending the interregeneration period under the current conditions, increasing the efficiency of the C5 fraction by lowering the pressure in the reactor without changing the interregeneration period, - lowering investment outlays and without shortening the interregeneration period as a result of reducing costs of compressors and reactors, the possibility of a significant increase in capacity without shortening the inter-regeneration period, provided that the equipment capacity is sufficient. heating elements.

In the reforming process using the catalyst according to the invention, 1 to 20 moles of hydrogen are typically used. per mole of hydrocarbon entering the reforming zone, and excellent results are obtained when using hydrogen · · In an amount of 2–6. moles per mole of hydrocarbon. The hourly volumetric capacity of the liquid is 0.1-10, preferably 1-5 h -1. This value is higher than that permanently achieved in continuous reforming with a high-quality existing catalyst. This feature. The invention is of great economic importance as it allows continuous reforming to be carried out with unchanged yield with less catalyst or a significant increase in yield with the same amount of catalyst as used for a conventional catalyst, without shortening the interregeneration period.

EXAMPLE 1 Pure metallic aluminum granules were dissolved in hydrochloric acid to obtain a sol to which was added tin chloride in such an amount that the tin content in the catalyst was about 0.2 / by weight. To the tin-containing aluminum zoyl is added to the tin-containing hydrogel and the resulting solution gels through iwcrophenie into an oil bath to give a tin-containing hydrogel. aluminum in the form of balls o. 1 cm in diameter. The obtained product is subjected to maturing and rinsing, followed by drying and calcining, obtaining y-Al / a containing an evenly distributed tin oxide in an amount of about 0.2 / by weight. and Chlorides - in a total amount of about 0.3 / · by weight. Additional details for preparing the carrier are set out in U.S. Patent No. 2,020,314.

An impregnation solution is prepared containing 'chloroplatinic acid, cobalt chloride' and hydrogen chloride. The tin-containing aluminum carrier 41 is mixed with the solution. The amount of the components of the impregnating solution is chosen so that the final product contains, calculated as an element, 0.30 · / · weight platinum and 1.0 · / · cobalt. IN

322 To ensure uniform distribution of the metal components in the carrier, hydrochloric acid is used in an amount of about 3% by weight of alumina. The impregnation is carried out by adding the carrier to the impregnation mixture under constant stirring. The volume of the solution is approximately equal to the free space in the medium. The impregnation mixture is kept in contact with the support for 0.5 to 3 hours at a temperature of about 21 ° C. The temperature of the impregnating mixture is then raised to about 106^ABOUTC and the excess solution evaporates in about an hour. The dried impregnated carrier is subjected to an oxidative treatment for about 0.5 hours in a stream of dry air having a temperature of about 525 ° C and a volumetric flow rate of about 500 hours^-1. In the oxidation stage, the metallic components are almost completely converted into the corresponding oxides. The oxidized product is subjected to a halogenation treatment consisting in passing a stream of air containing H₂O and HCl in a mole ratio of about 30: 1 for about 2 hours at 525 ° C. In order to bring the halogen content of the catalyst to about 1.09% by weight, the product is then subjected to a dry air stream of 525 ° C at a volumetric flow rate of about 500 hours for about 0.5 hours.^-!

The oxidized and halogenated catalyst is subjected to a reduction pretreatment, which. its purpose is to transform the platinum component into the elemental state while maintaining the tin component in a positive oxidation state. The treatment consists in contacting the catalyst .. for about · hour · at a temperature of about 566 ° C, with a stream of hydrogen which is below the hydrocarbons and containing less than 5 parts by volume per million parts of gas. The pressure in the pre-reduction step is slightly above atmospheric and the volumetric flow rate of the stream. hydrogen through the catalyst is about

400 hour-1.

Reduced sample testing. Electron Magnetic Resonance Imaging of the catalyst shows that substantially all of the platinum component is reduced while the tin component remains in the form of an oxide. Controlled reduction trials and electron magnetic resonance data show that substantially all of the cobalt component remains in the form of the reducible oxide. Investigation of the crystallites contained in the catalyst according to the invention_in cobalt, carried out using the X-ray technique. and electron magnetic resonance, after exposing the catalyst to hydrocarbons in the reforming operation described below, show that substantially all of the cobalt component · is reduced to its elemental state under these conditions. '

Analysis of the reduced catalyst shows the following component content (calculated as elements): platinum about 0.30 wt%, cobalt about 1.0 wt%, tin about 0.2 wt%,. chlorides about 1.09% by weight. This corresponds to a mole ratio of tin to platinum of 1.1 × 65 and a mole ratio of cobalt to platinum of 11: 1. The obtained acid multi-metal catalyst was marked with the symbol "A".

Example II. In order to compare the new acid poly metal catalyst according to the invention with the known catalyst, two or more times, studies were carried out to emphasize the benefits of the interaction of the cobalt component with the tin component and platinum. The product obtained as described in Example 1 and marked with the symbol "A" was used as the acidic multi-fluid catalyst. As a control catalyst, a bi-metal weforming catalyst was used, containing platinum and tin as a ucornladder-dehydration component, a chloride component and as a? -A1? Support. The composition of this catalyst, marked "B", is as follows: about 0.6% by weight of platinum, about 0.5% by weight of tin, and about 1.19% by weight of chloride. The catalyst was prepared as described in Example 1, except that the cobalt component was excluded and the tin and platinum content was increased two- and two- and a half-fold, respectively.

The catalysts will be used separately in accelerated and stringent reforming in order to obtain in a relatively short time information about their relative activity, selectivity and durability in the process of and reforming the low-octane gasoline fraction. In both tests, the raw material used was the low-grade gasoline fraction, the characteristics of which are presented in Table 1. In both cases, the test was carried out under substantially anhydrous conditions. The only significant source of water was present in the raw material in the amount of 14-18 parts by weight per million parts of this raw material. Both tests were performed under essentially sulfur-free conditions. The only source of sulfur was the raw material in which it was present in the amount of 0.1 parts per million parts of the raw material.

Table I

Characteristics of reformed gasoline

<td> 1</td><td> 2</td>

<td>Density at 15 ° C</td><td> 0,7398</td>

<td>Distillation profile, ° C</td><td></td>

<td>the beginning of the boil</td><td> 80 ,</td>

<td>5% boiling point</td><td> 93</td>

<td> 10% ”</td><td> 99</td>

<td> 30% ” '</td><td> 111'</td>

<td> 50% ”</td><td> 118</td>

<td>70% c</td><td> 140</td>

<td> 90% ”</td><td>J60</td>

<td>end of boiling</td><td> 190</td>

<td>Chlorides, parts by weight n £</td><td></td>

<td>- million ' .</td><td> 0,35</td>

<td>Nitrogen, parts per million by weight</td><td> 0,2</td>

<td>Sulfur, parts per million by weight</td><td>Ol</td>

<td>.Water, parts per million by weight</td><td> 14-18 ,</td>

<td>Octane number</td><td> 41,0</td>

<td>Paraffins,% by volume</td><td> 67</td>

<td>.Naphthenes,% by volume</td><td> 21,2</td>

<td>Aromatic compounds,</td><td></td>

<td>% by volume</td><td> 11,8</td>

322

The accelerated reforming attempt was aimed at testing in a very short time whether the assessed catalyst has. improved performance when applied to stringent reforming. Each trial consisted of a series of 24-hour Assessment Periods, subdivided into a 12-hour reforming period in which reformed product C was taken from the machine and analyzed.₅+ i 12-h ^^ j ^ th period of stoppage. Both tests were carried out under identical conditions, with a liquid flow rate of 3.0 h^-1, a pressure of 21.4 atm, a gas to oil ratio of 10: 1, and by continuously varying the reactor inlet temperature so as to maintain the octane number value of 100 for the C5 + fraction.

Both tests were carried out in a pilot downstream reforming plant, including a fixed bed reactor of the catalyst to be evaluated, a hydrogen separation zone, a reflux column and appropriate heating devices, pumps, condensers, compressors and other conventional equipment. The flow system of the installation provides for mixing the recycle hydrogen stream with the subssrate and heating the mixture to the desired conversion temperature. The heated mixture is fed from the top to the reactor containing the tested catalyst in a fixed bed. The effluent is collected at the bottom of the reactor, cooled to about 13 ° C, and passed * through a gas-liquid separation zone where the hydrogen-rich gas phase is separated from the liquid hydrocarbon phase. A portion of the gas phase is passed continuously through a sodium scrubber with a high surface area, and the water and sulfur-free hydrogen stream is returned to the reactor to feed the hydrogen cycle. The excess gas phase from the separation zone is recovered as a hydrogen-containing product stream (usually called excess recycle gas). The liquid phase is withdrawn from the separation zone and fed to a debutanizing column where the C-C4 light fractions are collected, and the main product is withdrawn from the bottom of the C5 + reformed fraction stream.

The results of separate tests carried out on the particularly preferred catalyst according to the invention, marked with the symbol "A" and the control catalyst, marked with the symbol "B" are shown in Table 2, expressed by the temperature in ° C at the inlet of the reactor, necessary for utayma, Table 2

Results of the Accelerated Reforming Attempt

<td rowspan="2">Cycle</td><td colspan="2">Catalyst "A"</td><td colspan="2">Catalyst "B"</td>

<td>Temperature ° C</td><td>The yield of the C fraction₅+</td><td>Temperature ° C</td><td>The yield of the C fraction₅⁺</td>

<td> 1</td><td> 510,3</td><td> 70,02</td><td> 535,6</td><td> 71,95</td>

<td> 2</td><td> 509,7</td><td> 69,05</td><td> 536,9</td><td> 72,57</td>

<td> 3</td><td>Ś13.6</td><td> —</td><td> 538,9</td><td> —</td>

<td> 4</td><td> 514,2</td><td> 70,27</td><td> 539,7</td><td> 71,64</td>

<td> 5</td><td> 515,6</td><td> —</td><td> 540,0</td><td> —</td>

<td> 6</td><td> 516,7</td><td> 70,36</td><td>541J</td><td> 71,56</td>

<td> 7</td><td> 517,8</td><td> —</td><td> 542,2</td><td> —</td>

<td> 8</td><td> 517,5</td><td> 70,96</td><td> 542,5</td><td> 72,07</td>

<td> 9</td><td> 519,2</td><td> —</td><td> —</td><td> —</td>

the assumed value of the octane number and the amount of the C5 + reformed product in% by volume of the raw material.

The data presented in Table 2 show that the main effect of introducing the platinum-tin cobalt component into the double-metal catalyst is a significant improvement in its quality, expressed as an increase in activity and its stability, which allows to obtain better results with the use of a much smaller amount of platinum than in the absence of the component. cobalt.

Thus, the data presented in the table shows that the acid multimetallic catalyst of the present invention far outperforms the control catalyst under the stringent reforming conditions. As detailed above, a good measure of the activity of a reforming catalyst is the reactor inlet temperature to achieve the target octane number of the reformed product, and the data on this variable in Table 2 clearly show that Catalyst "A" is much more active. from catalyst "B". The activity difference corresponds to an inlet temperature difference of 20 ° C or more. This is a remarkable difference considering that a temperature difference of 10-11 ° C, typically, doubles the reaction rate.

Thus, this 20 ° C difference means that the catalyst of the invention is approximately four times more active than the control catalyst. An example of the benefits resulting from this is illustrated by the data for the test cycle 8 (for -192 hours). At this point, catalyst "A" required the reactor inlet temperature to maintain the assumed octane rating of 517.5 ° C, and at the same time catalyst "B" 542.5 ° C. The temperature difference of 25 ° C is clear evidence of the ability of the catalyst of the invention to significantly accelerate the reforming rate without significantly altering the yield of the C5 + fraction. The activity of the catalyst is, however, only one of the characteristics of the catalyst and, in order to prove the superiority of the catalyst according to the invention, it must be shown that it is also more selective and more stable. The selectivity is measured directly by the yield of the C5 + fraction, and the data in Table 2 [show that the yield of the C5 + fraction with the use of catalyst "A" is equal to that obtained with the use of catalyst "B". (The dashes in Table 2 indicate that the product was not analyzed in the given period). Persistence is assessed by the rate of change in activity and selectivity as explained above. The data on the change of temperature presented in Table 2 to maintain the assumed yield of the C5 + fraction clearly cancel out the excellent stability of the catalyst according to the invention.

Taken together, the data in Table 2 shows that the cobalt component is an efficient and effective promoter of the platinum and tin containing acid reforming catalyst under stringent conditions.

Example III. To further illustrate the superiority of the polymephalic acid catalyst of the present invention, p99 322 was used.

permanent comparative studies between Catalyst "A" and Control Catalyst "B" in a pilot plant with substantially the same flow pattern as set forth in Example II. The composition of the reforming substrate is shown in Table 3.

Table 3

Characteristics of reformed gasoline

<td> 1</td><td> 2</td>

<td>Density at 15 ° C</td><td> 0,7560</td>

<td>Distillation profile, ° C</td><td></td>

<td>the beginning of the boil</td><td> 95</td>

<td>5% boiling point</td><td> 105</td>

<td> 10% /</td><td> 110</td>

<td> 30% „</td><td> 121</td>

<td> 50% „</td><td> 134</td>

<td>70% n</td><td> 147</td>

<td> 90% *</td><td> 163</td>

<td> 95% „</td><td> 170 .</td>

<td>end of boiling</td><td> \ 203</td>

<td>Chlorides, parts by weight na</td><td></td>

<td>million</td><td> 0,5</td>

<td>Nitrogen, parts by weight per million</td><td> 0,13</td>

<td>Sulfur, parts per million by weight</td><td>Ό, 1</td>

<td>Water, parts per million by weight</td><td> 5</td>

<td>Octane number</td><td> 46,9</td>

<td>Paraffins,% by volume</td><td> 47^7</td>

<td>Naphthenes,% by volume</td><td> 44,4</td>

<td>Aromatic compounds,% v / v</td><td></td>

<td>material</td><td>'Λ 7^,9</td>

Comparative tests were carried out under the same pressure conditions for both catalysts

21.4 atmospheres, a liquid volume flow rate of 2.5 hr -1, a 4: 1 mole ratio of recycle gas to hydrocarbon, and reactor inlet temperature varied continuously to maintain the octane number of C5 + reformed product at 100.

The test results are shown in Table 4. It is given therein. temperature at the inlet to the reactor, necessary to meet the assumed octane number of the reformed product and product yield C5 + in the volumetric flow, converted to, m³ per kg of catalyst. The time is given in terms of m3 flux per kg catalyst. ;

As can be seen from the data in Table 4, long-term installation trials. pilot post20

Table 4

Test results in a pilot plant

<td rowspan="2">Time m3 / stream / kg</td><td colspan="2">Catalyst "A"</td><td colspan="2">Catalyst "B"</td>

<td>distemper- round ° C</td><td>yield of the C5 + fraction</td><td>distemper- round ° C</td><td>yield of the C5 + fraction</td>

<td> 1</td><td> 2</td><td> 3</td><td> 4</td><td> 5</td>

<td> 0,35</td><td> 498</td><td> 74,0</td><td> 515</td><td> 79,0</td>

<td> 0,53</td><td> 496</td><td> 75,5</td><td> 516</td><td> 79,0</td>

<td> 0,70</td><td> 497</td><td> 73,5</td><td> 521</td><td> 79,0</td>

<td> 0,88</td><td> 498</td><td> 75,0</td><td> 524</td><td> 79,2</td>

<td> 1,05</td><td> 499</td><td> 74,0</td><td> 525</td><td> 78,9</td>

<td> 1,23</td><td> 499</td><td> 76,1</td><td> . 526</td><td> 78,0</td>

<td> 1,40</td><td> 500</td><td> 76,0</td><td> 529</td><td> 77,6</td>

<td> 1,58</td><td> 501</td><td> 74,0</td><td> 530</td><td> 77,9 .</td>

<td> 1,75</td><td> 501</td><td> 76,0</td><td> 531</td><td> 77,9</td>

<td> 1,93</td><td> 504</td><td> 76,0</td><td> 533</td><td> 77,9</td>

<td> 2,10</td><td> 507</td><td> 76,3</td><td> ' 536</td><td> 77,0</td>

<td> 2,28</td><td> 508</td><td> 75,7</td><td> . 540</td><td> 76,4</td>

<td> - 2,45</td><td> 509</td><td> 76,1</td><td> —</td><td> —</td>

<td> 2,63</td><td> 512</td><td> 76,2</td><td> —</td><td> —</td>

<td> 2,80</td><td> 513</td><td> 76,2</td><td> —</td><td> —</td>

<td> 2,98</td><td> 515</td><td> 76,5</td><td> —</td><td> —</td>

<td> 3,15</td><td> 518 .</td><td> —</td><td> —</td><td> —</td>

<td> 3,33</td><td> 521</td><td> —</td><td> —</td><td> —</td>

<td> 3,50</td><td> 524</td><td> —</td><td> —</td><td> - — -</td>

claim the exceptional activity and the stability of the activity of the multi-metal acid catalyst according to the invention.