EA041286B1 - METHOD FOR PRODUCING BTX FROM A MIXTURE OF C5-C12 HYDROCARBONS - Google Patents

Description

The field of technology to which the invention belongs

The invention relates to a method for producing a hydrocracking catalyst. In addition, the invention relates to a method for producing a mixture of benzene, toluene and xylenes (BTX) from a mixed feedstock containing C5-C12 hydrocarbons by contacting said feedstock with said catalyst in the presence of hydrogen.

State of the art

It has previously been described in WO 02/44306 A1 and WO 2007/055488 A1 that compounds of aromatic hydrocarbons and LPG (liquefied petroleum gas; a mixture of C ₂ , C ₃ and C ₄ hydrocarbons) can be obtained from a mixed hydrocarbon feed having a boiling range 30-250°C. Therefore, a hydrocarbon feedstock having a boiling range of 30-250°C and hydrogen are introduced into the reaction zone in which said hydrocarbon feedstock is converted in the presence of a catalyst into aromatic hydrocarbon compounds, predominantly BTX, by hydrodealkylation and/or transalkylation, and into non-aromatic hydrocarbon compounds , mainly LPG, due to hydrocracking, and compounds of aromatic hydrocarbons and LPG are separated, respectively, by gas-liquid separation and distillation. The processes according to WO 02/44306 A1 and WO 2007/055488 produce a product stream containing a relatively large amount of non-aromatic hydrocarbons that boil in the BTX range, making it impossible to obtain chemically pure BTX without the use of solvent extraction methods, and a relatively large amount of fuel gas due to received CIS.

US 2009/0272672 discloses a process for the catalytic hydrodealkylation of C ₈ -C ₁₃ alkylaromatics mixed with C ₄ -C ₁₀ aliphatic and cycloaliphatic products which undergo aromatization and subsequent hydrodealkylation. In this method, hydrocarbons are treated with ZSM-5 zeolite having a SiO ₂ /Al ₂ O ₃ molar ratio of 5-100, which is modified with a platinum-molybdenum pair, at a temperature of 400 to 650°C, a pressure of 2 to 4 MPa and molar ratio H ₂ /feedstock in the range from 3 to 6.

US 2006/0287564 describes a process for increasing the yield of the product, benzene, from a mixture of hydrocarbons, which involves separating the hydrocarbon feed into a C6 or lower hydrocarbon stream and a _C7 or higher hydrocarbon stream. The C6 or lower hydrocarbon stream is separated into a non-aromatic hydrocarbon stream and an aromatic hydrocarbon stream by a solvent extraction process.

A C ₇ or higher hydrocarbon stream is reacted in the presence of a catalyst containing platinum/tin or platinum/lead.

US 3,957,621 describes a process for treating a heavy reformate from which benzene and lighter components have been substantially removed. The effluent includes most of the benzene in the feed and may include a significant proportion of toluene.

WO 2013/182534 discloses a process for producing BTX from a C ₅ -C ₁₂ mixture of hydrocarbons using a hydrocracking/hydrodesulfurization catalyst. According to WO 2013/182534, this process produces a mixture that is substantially free of impurities boiling with BTX, so that chemically pure BTX components can be easily obtained.

Although chemically pure BTX components are advantageously obtained in WO 2013182534, there is a demand for a process in which a product stream is obtained having a composition containing an increased amount of desirable components such as BTX and LPG and a lower amount of components such as methane.

US 2004/082461 discloses a process for impregnating with a Group VIII metal a molecular sieve extrudate and a binder, in which the binder contains a low acid refractory oxide binder material substantially free of alumina, by a) contacting the molecular sieve extrudate and binder with an aqueous solution of nitrate a salt of the corresponding Group VIII metal having a pH below 8, in which the molar ratio between the Group VIII metal cations in solution and the number of sorption sites present in the extrudate is equal to or greater than 1, and b) drying the molecular sieve extrudate and the binder obtained in step a).

US 2014/0316179 discloses a process for the preparation of a hydrocarbon aromatization catalyst. The method for producing a shaped catalyst may include: mixing uncalcined Ge-ZSM-5 zeolite and a binder to form a mixture; molding the mixture into molded zeolite; calcining the molded zeolite to form a molded zeolite containing up to 0.1 wt.% residual carbon or less; ion exchange of the molded zeolite with cesium to suppress the acidity of the zeolite; deposition of platinum on molded zeolite; and heating the molded zeolite to finally obtain a catalyst; in which the final catalyst contains from 4.0 to 4.8 wt.% cesium and from 0.4 to 1.5 wt.% platinum.

US 2014/039233 describes a catalyst composition suitable for converting alkanes having 3 to 12 carbon atoms into aromatic hydrocarbons, the catalyst composition comprising: MN/MA/Ga-zeolite, where MN is one or more noble metals and MA means one or more alkali metals and/or alkaline earth metals.

- 1 041286

The MN/MA/Ga zeolite is a zeolite containing: 0.01-10 wt.% MN based on the entire MN/MA/Ga zeolite; 0.01-10 wt.% MA based on the total MN/MA/Ga-zeolite; and 0.01-10 wt.% Ga based on the total MN/MA/Ga-zeolite.

The unpublished, co-pending application PCT/EP 2016/069554 describes a process for producing BTX using a hydrocracking catalyst, in which the hydrocracking catalyst comprises a molded body containing a zeolite and a binder and a hydrogenating metal deposited on the molded body, the hydrogenating metal being 0.010 -0.30 wt.% based on the entire catalyst, and where the zeolite is a ZSM-5 having a molar ratio of silicon dioxide (SiO ₂ ) to alumina (Al ₂ O ₃ ) 25-75. This application shows that such a ZSM-5 containing catalyst having a silica (SiO ₂ ) to alumina (Al ₂ O ₃ ) molar ratio of 2575 provides a hydrocracked product stream containing a small proportion of methane and substantially free of impurities boiling together with BTK, at a sufficiently high value of the mass flow rate.

The preparation of a hydrocracking catalyst may include a plurality of steps: obtaining a shaped body containing a zeolite and a binder, calcining the resulting shaped body, additional drying of the shaped body, deposition of the hydrogenating metal on the shaped body, washing or rinsing the shaped body with the precipitated hydrogenating metal, and heat treatment of the catalyst.

It would be desirable to obtain a hydrocracking catalyst with the desired activity in an efficient manner saving time, energy and materials in one or more of these steps.

Brief summary of the invention

It is an object of the present invention to provide a process for producing a hydrocracking catalyst and a process for converting a C ₅ -C ₁₂ hydrocarbon feed stream into a BTX containing product stream that satisfies the above and/or other needs.

Therefore, the present invention provides a process for producing a hydrocracking catalyst, comprising:

(i) obtaining a molded mass containing a zeolite and a binder, and the molded mass is obtained by shaping, calcining and cooling, where the zeolite is ZSM-5 having a molar ratio of silicon dioxide (SiO ₂ ) to alumina (Al ₂ O ₃ ) equal to 25-75, (ii) optionally drying the molded body at a temperature of 100-300°C for at least 1 hour, (iii) deposition of the hydrogenating metal on the molded body by impregnation for at most 2 hours, so that the amount hydrogenating metal was 0.010-0.30 wt.% based on the entire catalyst, (iv) optionally washing the deposited metal molded mass with water and (v) heat treating the precipitated metal molded mass in air at a temperature of 250300° C. for a period of 1- 5 o'clock

In addition, the present invention has developed a process for producing BTX, which includes the production of a hydrocracking catalyst according to the method according to the invention and additional steps:

(a) obtaining a hydrocracking feed stream containing C ₅ -C ₁₂ hydrocarbons, (b) contacting the hydrocracking feed stream in the presence of hydrogen with a hydrocracking catalyst under process conditions including a temperature of 425-580°C, an overpressure of 300-5000 kPa and a mass velocity stream 3-30 h' ¹ with the formation of the stream of hydrocracking product containing BTX and (c) separating BTX from the stream of hydrocracking product.

The hydrocracking catalyst obtained by the method according to the invention, which is used in the method for producing BTX according to the invention, includes a molded mass containing a zeolite, a binder, and a hydrogenating metal deposited on the molded mass, and the amount of hydrogenating metal is 0.010-0.30 wt. % based on the total catalyst, and the zeolite is ZSM-5 having a molar ratio of silicon dioxide (SiO ₂ ) to alumina (Al ₂ O ₃ ) equal to 25-75. The zeolite in the molded catalyst is in hydrogen form.

Surprisingly, the inventors found that a high efficiency catalyst having a molar ratio of silica (SiO ₂ ) to alumina (Al ₂ O ₃ ) of 2575 can be obtained in a very efficient manner, with the elimination or reduction in the duration of some stages that were usually considered necessary for the preparation of catalysts.

It has been considered in the prior art that it is necessary to pre-dry the molded body containing the zeolite and the binder before precipitation of the hydrogenation catalyst. It has been found that said pre-drying is optional for the molded body according to the invention in order to obtain the desired catalyst characteristics.

The molded mass is subjected to impregnation to deposit the hydrogenating metal on the molded mass. Surprisingly, it has been found that the duration of impregnation can be significantly reduced, for example, to a period of no more than 2 hours, in order to provide the desired catalytic properties.

- 2 041286 lyzer. Typically, the duration of impregnation in conventional processes at a temperature of approximately 60°C was 24 hours.

In addition, it has been found that the step of washing or rinsing with water the metal deposited on the molded body can be omitted. The terms rinsing and rinsing are used interchangeably here. Conventional washing or rinsing processes require a large amount of distilled water and thus eliminating this step reduces costs.

The product thus obtained is subsequently calcined, also for a short period of time, i.e. at most 5 hours. Typically, the calcination time in conventional processes was 20-24 hours.

Thus, in the method according to the invention, the catalyst is obtained in a very short period of time compared to the method known from the prior art, and thus a catalyst with the desired characteristics is obtained.

Detailed description of the invention

The process according to the invention, using the catalyst thus obtained, results in a hydrocracking product stream containing a small proportion of methane and practically free of impurities, boiling together with BTX, at a sufficiently high mass flow rate. The low proportion of methane means that more valuable components such as C2-C4 hydrocarbons and BTX are present in the hydrocracking product stream. The absence of BTX-boiling impurities in the product stream allows chemically pure BTX to be obtained by simple distillation of the product stream. This can be done at a relatively high mass flow rate, which means that the desired products can be obtained at a high rate, so a small reactor volume is required, resulting in lower capital costs (CAPEX).

Used in the invention, the term C _n hydrocarbons, where n is a positive integer, is used to refer to all hydrocarbons having n carbon atoms. In addition, the term C _n+ hydrocarbons is used to refer to all hydrocarbon molecules having n or more carbon atoms.

Therefore, the term C ₅₊ hydrocarbons is used to refer to a mixture of hydrocarbons having 5 or more carbon atoms.

Step a).

According to step a) of the process according to the invention, a hydrocracking feed stream containing C ₅ -C ₁₂ hydrocarbons is obtained.

Hydrocracking Feed Stream

Used in the method of the present invention, the hydrocracking feed stream is a mixture containing C ₅ -C ₁₂ hydrocarbons, preferably having a boiling point in the range of 30-195°C. Preferably, the hydrocracking feed stream mainly contains C5-C8 hydrocarbons.

The hydrocracking feed stream can be provided by obtaining a fresh feed stream and optionally mixing this stream with another stream, such as a recycle stream from a hydrocracked product stream, such as toluene, if desired. This mixing with another stream is optional. If mixing, for example, with a recycle stream does not occur, then the hydrocracking feed stream is the same as the fresh feed stream. Suitable examples of a fresh feed stream include, but are not limited to, first stage or multi-stage hydrotreated pyrolysis gasoline, straight run naphtha, hydrocracked gasoline, light coking naphtha and coke oven light gas oil, fluid catalytically cracked gasoline (FCC), reformate, or mixtures thereof, which are optionally subjected to processing such as hydrogenation, enrichment of monoaromatic compounds and/or removal of pentanes.

For example, a typical composition of the first stage of pyrolysis gasoline hydrotreatment may contain: 10-15 wt.% C ₅ olefins, 2-4 wt.% C ₅ paraffins and cycloparaffins, 3-6 wt.% C ₆ olefins, 1-3 wt.% C ₆ paraffins and naphthenes, 25-30 wt.% benzene, 15-20 wt.% toluene, 2-5 wt.% ethylbenzene, 3-6 wt.% xylenes, 1-3 wt.% trimethylbenzenes, 4-8 wt. .% dicyclopentadiene and 10-15 wt.% C9+ aromatic hydrocarbons, alkylstyrenes and indenes; for example, see table. E3.1 from Applied Heterogeneous Catalysis: Design, Manufacture, and Use of Solid Catalysts (1987) JF Le Page.

Preferably, the non-aromatic compounds in the hydrocracking feed stream are saturated (eg, by pre-hydrogenation) to reduce the exothermic effect in the bed containing the hydrocracking catalyst used in the process of the invention. Therefore, preferably, the fresh feed stream is a stream that has already been hydrogenated. Advantageously, hydrodesulfurization also takes place during the hydrogenation. This provides the advantage that the resulting fresh feed stream has a low sulfur content. The low sulfur content of the fresh feed stream is advantageous because the hydrocracking catalyst used according to the invention does not need to have hydrodesulfurization characteristics.

The fresh feed stream or hydrocracking feed stream used in the process of this ISO

- 3 041286 shaving, may contain up to 300 ppm. by mass of sulfur (that is, the mass of sulfur atoms found in any compounds, related to the mass of raw materials).

In some embodiments, the fresh feed stream used in the process of the present invention is a stream that has been treated to be enriched in monoaromatic compounds. As used herein, the term monoaromatic compound refers to a hydrocarbon compound having only one aromatic ring. Means and methods suitable for increasing the content of monoaromatic compounds in a mixed hydrocarbon stream are well known in the art, for example, the Maxene process; see Bhirud (2002) Proceedings of the DGMK-conference 115-122 (Proceedings of the conference).

In some embodiments, pentanes have been removed from the fresh feed stream used in the process of the present invention. Preferably the fresh feed stream contains at most 5 wt.% C ₅ hydrocarbons, more preferably at most 4 wt.%, at most 3 wt.%, at most 2 wt.%, or at most 1 wt.% C ₅ hydrocarbons.

Preferably, the hydrocracking feed stream is produced in a process that does not include a benzene or C ₆ removal step. This means that the intentional removal of benzene is not carried out in the production of a hydrocracking feed stream or fresh feed stream. According to the present invention, benzene-boiling impurities present in the hydrocracking feed stream are advantageously converted into useful LPG.

Preferably, the hydrocracking feed stream may contain at least 10 wt.% benzene, for example, at least 20 wt.% benzene, at least 30 wt.% benzene, or at least 40 wt.% benzene, and/or the most more than 90 wt.% benzene, for example, at most 80 wt.%, at most 70 wt.%, at most 60 wt.% or at most 50 wt.% benzene.

Preferably, the fresh feed stream may contain at least 10 wt.% benzene, for example, at least 20 wt.% benzene, at least 30 wt.% benzene or at least 40 wt.% benzene, and/or at most 90 wt.% benzene, for example, at most 80 wt.%, at most 70 wt.%, at most 60 wt.% or at most 50 wt.% benzene.

Step b).

According to step b) of the process of the invention, the hydrocracking feed stream is contacted, in the presence of hydrogen, in a hydrocracking reactor with a hydrocracking catalyst prepared according to the process of the invention.

The product obtained from the hydrocracking step of the process of the present invention (hydrocracking product stream) contains LPG, BTX and methane.

The term LPG as used in the invention refers to the common abbreviation for the term liquefied petroleum gas. LPG typically consists of a mixture of C2-C4 hydrocarbons, ie a mixture of _C2 , C3, and _C4 hydrocarbons.

The term BTX used in the invention is well known in the art and refers to a mixture of benzene, toluene and xylenes.

As used herein, chemically pure BTX refers to a mixture of hydrocarbons containing less than 5% by weight of hydrocarbons other than benzene, toluene and xylenes, preferably less than 4% by weight of hydrocarbons other than benzene, toluene and xylenes, more preferably less than 3% by weight of hydrocarbons other than benzene, toluene and xylenes, and most preferably less than 2.5% by weight of hydrocarbons other than benzene, toluene and xylenes.

In addition, chemically pure BTX obtained by the method of the present invention contains less than 1 wt.% non-aromatic C ₆₊ hydrocarbons, preferably less than 0.7 wt.% non-aromatic C ₆₊ hydrocarbons, more preferably less than 0, 5 wt.% non-aromatic C ₆₊ hydrocarbons and most preferably less than 0.2 wt.% non-aromatic C ₆₊ hydrocarbons. The most significant impurities are non-aromatic compounds that have a boiling range close to that of benzene, including (but not limited to) cyclohexane, methylcyclopentane, n-hexane, 2-methylpentane, and 3-methylpentane. The most significant non-aromatic compounds that have a boiling range close to that of toluene include 2,4-dimethylpentane, 3,3-dimethylpentane, and 2,2-dimethylpentane.

Therefore, the hydrocracked product stream is substantially free of non-aromatic C ₆₊ hydrocarbons. As used herein, the expression hydrocracked product stream is substantially free of non-aromatic C6+ hydrocarbons means that said hydrocracked product stream contains less than 1 wt. % non-aromatic C ₆₊ hydrocarbons, preferably less than 0.7 wt. % non-aromatic C ₆₊ hydrocarbons, more preferably less than 0.5 wt.% non-aromatic C ₆₊ hydrocarbons and most preferably less than 0.2 wt.% non-aromatic C ₆₊ hydrocarbons.

The term aromatic hydrocarbon is very well known in the art. Accordingly, the term aromatic hydrocarbon refers to cyclically conjugated hydrocarbons having a stability (due to delocalization) that is significantly greater than that of the hypothetical

- 4 041286 localized structures (eg Kekule structures). The most common method for determining the aromaticity of a given hydrocarbon is to study diatropicity in the 1H NMR spectrum, for example, the presence of chemical shifts in the range from 7.2 to 7.3 ppm. for the protons of the benzene ring.

The hydrocracked product stream obtained in the process of the present invention preferably contains less than 5% by weight of methane. Preferably, the hydrocracked product stream obtained in the process of the present invention contains less than 4 wt.% methane, more preferably less than 3 wt.% methane, even more preferably less than 2 wt.% methane, even more preferably less, than 1.5 wt.% methane, even more preferably less than 1.4 wt.% methane, even more preferably less than 1.3 wt.% methane, even more preferably less than 1.2 wt.% methane , even more preferably less than 1.1 wt.% methane, and most preferably less than 1 wt.% methane.

Preferably, the hydrocracked product stream is also substantially free of C ₅ hydrocarbons. As used herein, the expression hydrocracked product stream is substantially free of C ₅ hydrocarbons means that the hydrocracked product stream contains less than 1 wt% C ₅ hydrocarbons, preferably less than 0.7 wt% C ₅ hydrocarbons, more preferably less than 0.6 wt.% C ₅ hydrocarbons and most preferably less than 0.5 wt.% C ₅ hydrocarbons.

The main advantage of the process of the present invention is that the hydrocracked product stream is substantially free of non-aromatic C6+ hydrocarbons, as these hydrocarbons typically have a boiling range close to that of C6+ aromatics. Therefore, it may be difficult to separate non-aromatic C6+ hydrocarbons from aromatic C6+ hydrocarbons contained in the hydrocracked product stream by distillation.

Process conditions

The process conditions under which the feed stream is hydrocracked are a factor in determining the composition of the hydrocracked product stream.

Usually, if the space velocity is too high, not all of the impurities boiling with BTX are hydrocracked, so chemically pure BTX cannot be obtained by simple distillation of the product stream. However, if the space velocity is too low, the methane yield increases at the expense of propane and butane. In addition, at higher space velocity, a smaller reactor volume is required and thus capital costs are reduced. Therefore, it is advantageous to carry out the process of the invention at an increased space velocity, at which substantially all of the impurities boiling together with the BTX undergo hydrocracking.

It has been found that the hydrocracking step (b) can be advantageously carried out at a high space velocity, and at the same time hydrocracking of almost all impurities boiling with BTX is ensured due to the high activity of the catalyst. Without going into theory, the inventors believe that in the catalyst used in the method of the invention, the hydrogenating metal and zeolite are in close proximity to each other, which means a shorter diffusion path between these two centers. This allows for the hydrocracking of impurities boiling with BTX at a high volumetric feed rate.

Accordingly, in some preferred embodiments, step (b) is carried out at a mass flow rate (WHSV) of 3-30 h ^-1 , for example, at least 5 h ^-1 , at least 6 h ^-1 , at least 7 h ^-1 or at least 8 h ^-1 , and/or at most 25 h ^-1 , at most 20 h ^-1 , at most 15 h ^-1 , at most 10 h ^-1 . At a high mass flow rate, such as at least 8 h ^-1 , a small volume reactor can be specifically used, which reduces capital costs.

In addition, it has been found that step (b) can be carried out at a relatively low temperature. This provides increased process flexibility as well as reduced heat load and can extend the process cycle time. Accordingly, in preferred embodiments, step (b) is carried out at a temperature of 425-445°C. In other embodiments, step (b) is carried out at 450-580°C. An increased temperature range results in a high hydrocracking conversion.

Hydrocracking of the feed stream is carried out at an overpressure of 300-5000 kPa, more preferably at an overpressure of 600-3000 kPa, particularly preferably at an overpressure of 1000-2000 kPa and most preferably at an overpressure of 1200-1600 kPa. By pressurizing the reactor, the degree of conversion of C ₅₊ non-aromatic compounds can be increased, however, increasing the pressure also increases the yield of methane and the hydrogenation of aromatic rings to cyclohexane derivatives, which can be split to form LPG components. This leads to a decrease in the yield of aromatic compounds with increasing pressure, and since a certain amount of cyclohexane and its isomer -methylcyclopentane is not completely hydrocracked, high purity benzene can be obtained as a result at a pressure of 1200-1600 kPa.

The hydrocracking step is carried out in the presence of an excess of hydrogen in the reaction mixture. This means that an overstoichiometric amount of hydrogen is present in the hydrocracked reaction mixture. Preferably, the molar ratio of hydrogen to hydrocarbon molecules (HC)

- 5 041286 (H2/HC molar ratio) in the reacting feed is between 1:1 and 4:1, preferably between 1:1 and 3:1 and most preferably between 2:1 and 3:1. Increased purity of benzene in the product stream can be obtained by selecting a relatively low H2/HC molar ratio. In this context, the term hydrocarbon molecules means all hydrocarbon molecules present in the reacting feed, such as benzene, toluene, hexane, cyclohexane, etc. It is necessary to know the composition of the feed in order to then calculate the average molecular weight of this stream so that the correct value can be calculated. hydrogen supply rate. An excess amount of hydrogen in the reaction mixture inhibits the formation of coke, which presumably leads to catalyst deactivation.

Catalyst

The catalyst used in the method of the present invention is obtained by the method according to the invention.

In step (i) of the process for producing a hydrocracking catalyst according to the invention, a zeolite and binder-containing molded body is obtained, in which the zeolite is ZSM-5 having a molar ratio of silica (SiO ₂ ) to alumina (A12O3) of 25:75 . The shaped mass is obtained by molding, for example, extrusion of the zeolite and binder into a desired shape, calcination in air, for example, at a temperature between 400°C and 600°C, for example, for 1 to 16 hours, and cooling to room temperature. Such molded mass obtained by molding (extrusion) followed by calcination and cooling is commercially available. The molded mass is stored until further use.

The molded body stored at room temperature can be dried in step (ii) of drying the molded body at 100-300° C. for at least 1 hour, to step (iii). When step (ii) is carried out, the drying is preferably carried out at 200-300°C for 12 hours. However, preferably, the method according to the invention does not include step (ii), i.e., step (iii) is carried out without heat treatment (temperature reaches 100 °C) after step (i).

In step (iii), the molded body is subjected to a wet impregnation to deposit the hydrogenating metal on the molded body. The impregnation is carried out for at most 2 hours, for example 0.5-2 hours or 0.5-1.5 hours, which is significantly shorter than in conventional processes. The impregnation can be carried out even at room temperature, further reducing costs.

The shaped mass stored with the precipitated hydrogenating metal may be processed in a washing or rinsing step (iv) to step (v). Washing can be done with a large volume of water, but can also be done by introducing the molded mass into a container with a relatively small amount of water (eg, 5 times the volume of the molded mass). Preferably, however, the method according to the invention does not include step (iv).

In step (v), the molded body stored with the precipitated hydrogenating metal is heat treated in air for a short period of time, i.e. 1-5 hours. The temperature is 250-300°C and preferably 270-290°C. Preferably, the heat treatment is carried out at a temperature of 270-290°C for 1-3 hours.

In particularly preferred embodiments of the invention, the method according to the invention does not include step (ii) and does not include step (iv).

The hydrocracking catalyst used in the process of the present invention contains a hydrogenating metal and a molded body containing ZSM-5 zeolite and a binder, with the hydrogenating metal deposited on the molded body. Examples of shaped mass include, but are not limited to, pellets, tablets, particles, and extrudates of a spherical or cylindrical shape. Typically, the molded body has an average diameter of about 0.1 to 15 mm, for example about 1 to 7 mm, typically 1.4 to 3.5 mm. The diameter is usually measured with a caliper. Typically, the shaped mass has an average particle length of 3 to 8 mm. Used in the invention, the term "average" means the arithmetic mean. One specific example of a shaped mass is a cylindrical extrudate having an average diameter of approximately 1.6 mm (1/16 inch) with an average length of the extrudates of approximately 3 to 8 mm. In such a catalyst, the distance between the hydrogenating metal and the acidic site of the zeolite is smaller than in a mixed catalyst of a molded mass of zeolite and a hydrogenating metal deposited on a binder. An example of the latter would be a mixture of a ZSM-5 zeolite extrudate and platinum deposited on molded Al ₂ O ₃ .

In addition, it has been observed that in the process of the present invention, the hydrocracked product stream has a desirable LPG composition. Typically high C2 LPG can be more valuable than high C3 LPG. It has been observed that the hydrocracking catalyst used in the present invention provides an increased C2/C3 ratio compared to a hydrocracking catalyst containing a mixture of a ZSM-5 zeolite extrudate and hydrogenating metal deposited on a molded binder when the hydrocracking feed stream is naphtha. Therefore, the process of the present invention, in which the hydrocracking feed stream is naphtha, can be advantageously used to produce a hydrocracked product stream having a high C2/C3 ratio.

Zeolites are molecular sieves that have three-dimensional structures with distinct characteristics.

- 6 041286 cash, pores, cavities with a certain pore size. As used herein, the term zeolite or aluminosilicate zeolite refers to aluminosilicate molecular sieves. An overview of the characteristics of molecular sieves is given, for example, in the chapter Molecular sieves of the Kirk-Othmer Encyclopedia of Chemical Technology, Volume 16, p. 811-853; in Atlas of Zeolite Framework Types, 5th edition, Elsevier, 2001. Zeolite ZSM-5 is a zeolite having an average pore size of approximately 5-6 A. Zeolite ZSM-5 is a zeolite with 10-membered rings, that is, formed from rings consisting of 10 tetrahedra [SiO ₄ ] and [AlO ₄ ] ^- . Zeolite ZSM-5 zeolite has MFT structure. The negative charge arising from [AlO ₄ ] ^- is neutralized by the cation in the zeolite.

The molar ratio of silicon dioxide (SiO ₂ ) to alumina (Al ₂ O ₃ ) in ZSM-5 zeolite is in the range of 25-75.

Using a zeolite having a molar ratio of SiO ₂ to Al ₂ O ₃ equal to 25-75, optimal catalyst performance was demonstrated both in terms of activity (which is measured by mass flow rate), benzene formation, and total aromatics content (BTK, ethylbenzene and heavier) and methane in the product stream. Means and methods for quantifying the molar ratio of SiO ₂ to Al ₂ O ₃ in zeolite are well known in the art, and include (but are not limited to) AAS (Atomic Absorption Spectroscopy), ICP (Inductively Coupled Plasma Spectrometry) or X-ray Fluorescence Analysis (XRF) . It is noted that the molar ratio of SiO ₂ to Al ₂ O ₃ indicated in the invention means the ratio in the zeolite before mixing with the binder for molding into a molded mass. Preferably, the molar ratio of SiO ₂ to Al ₂ O ₃ is measured by XRF.

Preferably, the ratio of silica to alumina for ZSM-5 zeolite is in the range of 30-65, more preferably 35-60, more preferably in the range of 40-55. With this ratio, especially when the ratio of silica to alumina is at least 35, the best balance is obtained between the amount of aromatic hydrocarbons and the content of methane in the hydrocracked product stream and the mass flow rate achieved for the desired purity of benzene.

The zeolite is in hydrogen form, that is, there is at least a portion of the original cations associated with it, which are replaced by H+ ions. Methods for converting aluminosilicate zeolites into the hydrogen form are well known in the art. The first method involves direct treatment using an acid, such as a mineral acid (HNO ₃ , HCl, etc.). The second method involves direct exchange using an ammonium salt (eg NH4NO3) followed by calcination.

Since the zeolite is in its hydrogen form, it does not undergo exchange with the base. For example, the zeolite is not exchanged with the basic ions sodium or cesium, preferably not ion exchanged with alkali or alkaline earth metals (eg, from Group IA and IIA of the Periodic Table of the Elements). The catalyst according to the invention may contain a total of less than 0.05 wt.% sodium and cesium, preferably less than 0.04 wt.% or less than 0.01 wt.%, based on the total weight of the catalyst. This catalyst may contain a total of less than 0.05 wt.% alkali and alkaline earth metal, preferably less than 0.04 wt.%, or less than 0.01 wt.% based on the total weight of the catalyst. It is desirable that the zeolite be free of alkali or alkaline earth metal additives.

The catalyst used in the process of the present invention contains 0.010-0.30% by weight, preferably 0.010-0.15% by weight of the hydrogenating metal. In the context of the present invention, the term wt.%, when considering the content of the metal, which is part of the catalyst, refers to the wt.% of the specified metal relative to the total weight of the hydrogenating metal, zeolite and binder. The amount of hydrogenating metal in the catalyst can be determined, for example, by analyzing the catalyst by XRF.

Preferably the catalyst contains 0.015-0.095% by weight of the hydrogenating metal. It has been found that a catalyst containing a hydrogenating metal in this range gives a particularly high yield of benzene. Even more preferably, the catalyst contains 0.020-0.090 wt.%, 0.035-0.080 or 0.0400.075 wt.% hydrogenating metal. For such catalysts, the amount of benzene lost (reduction in the amount of benzene in the hydrocracked product stream relative to the hydrocracking feed stream) by the process of the invention and the amount of methane in the hydrocracked product stream is relatively small. The total amount of aromatics (BTK, ethylbenzene and heavier) in the hydrocracked product stream is relatively high.

Preferably, the hydrogenating metal is at least one element selected from Group 10 of the Periodic Table of the Elements, or rhodium or iridium. Preferred group 10 elements are palladium and platinum, especially platinum.

The hydrocracking catalyst used in the process of the invention must have sufficient hydrogenating activity. Accordingly, it is preferred that the catalyst be free of secondary metals such as tin, lead or bismuth, which inhibit the hydrogenating activity of the hydrogenating metal. Preferably the hydrocracking catalyst used in the infusion process

- 7 041286 of the present invention, respectively, contains less than 0.01 parts of tin and less than 0.02 parts of lead and less than 0.01 parts of bismuth (based on 100 parts by weight of the entire catalyst), preferably less than 0.005 parts of tin and less than 0.01 parts lead and less than 0.005 parts bismuth (based on 100 parts by weight of the total catalyst).

Further, preferably, the hydrocracking catalyst used in the process of the present invention suitably contains less than 0.01 parts of molybdenum (based on 100 parts by weight of the total catalyst).

The hydrocracking catalyst contains a molded mass comprising a ZSM-5 zeolite and a binder. The hydrogenating metal is deposited on the molded mass. The presence of a binder in the molded mass provides adequate crush strength of the catalyst to withstand pressure in a larger reactor.

The binder material may be an inorganic oxide material. The binder material may include an aluminum or silicon-containing material such as silica, alumina, clay, aluminum phosphate, aluminosilicate, or combinations containing at least one of the above materials. Alumina (Al ₂ O ₃ ) is the preferred binder. The catalyst may contain up to 99 wt.%, for example, from 1 to 99 wt.%, for example, from 10 to 50 wt.% or from 20 to 40 wt.% of the binder, based on the total weight of the catalyst.

Step c).

The hydrocracking product stream contains methane, LPG, BTX. The term LPG as used in the invention refers to the common abbreviation for the term liquefied petroleum gas. Typically LPG consists of a mixture of C2-C4 hydrocarbons, ie a mixture of C ₂ , C ₃ , and C ₄ hydrocarbons. The method includes step c) separating BTX from the hydrocracked product stream. Step c) may also include separating the LPG from the hydrocracked product stream. The hydrocracked product stream may be separated using standard means and techniques suitable for isolating the methane and unreacted hydrogen contained in the hydrocracked product stream as a first separated stream; LPG contained in the hydrocracked product stream as a second separated stream; and BTK as the third dedicated stream. Preferably, the BTX-containing stream is separated from the hydrocracked product stream by gas-liquid separation or distillation. Benzene may be further separated from the stream containing BTX.

One non-limiting example of said process for splitting a hydrocracked product stream includes a series of distillation steps. The first distillation stage at moderate temperature is designed to separate most of the aromatic compounds (liquid product) from hydrogen, H2S, methane and LPG components. The gaseous stream from this distillation stage is further cooled (to approximately -30° C.) and distilled again to separate the remaining aromatics and most of the propane and butane. The product gas (primarily hydrogen, H2S, methane and ethane) is then further cooled (to about -100°C) to separate the ethane, leaving the hydrogen, H2S and methane in the gaseous stream which can be recycled back to the hydrocracking reactor. To control the content of H2S and methane in the reacting feed, a portion of said recycle gaseous stream is removed from the system as a purge. The amount of material that is blown depends on the content of methane and H ₂ S in the recycle stream, which, in turn, depends on the composition of the feed. Since the purge contains mainly hydrogen and methane, this stream can be conveniently used as a fuel gas, or it can be further processed (for example, in a pressure-surge adsorption unit) to separately separate the high purity hydrogen stream and the methane/H ₂ S mixture stream, which can be used as fuel gas.

In a further embodiment, the present invention relates to a process for producing benzene from a feedstock containing C ₅ -C ₁₂ hydrocarbons, said process comprising the process of the present invention for producing BTX, which further comprises the step of contacting the BTX (or only the toluene and xylenes fractions of the resulting BTX ) with hydrogen under conditions suitable to produce a hydrodealkylation product stream that contains benzene and fuel gas.

Conditions suitable for the production of a hydrodealkylation product stream containing benzene and fuel gas are well known and are described in detail, for example, in WO 2013/182534, which is incorporated into the invention by reference.

Hydrodealkylation processes for a mixture of hydrocarbons containing C6-C9 aromatics include thermal hydrodealkylation and catalytic hydrodealkylation; see for example WO 2010/102712 A2. In the context of the present invention, catalytic hydrodealkylation is preferred since this hydrodealkylation process generally has a higher selectivity to benzene than thermal hydrodealkylation. Preferably, catalytic hydrodealkylation is used wherein the hydrodealkylation catalyst is selected from the group consisting of supported chromium oxide catalyst, supported molybdenum oxide catalyst, platinum on silica or alumina, and platinum oxide on silica or alumina.

One skilled in the art can readily determine the process conditions used in

- 8 041286 hydrodealkylation, also described in the invention as hydrodealkylation conditions. For example, the process conditions used in thermal hydrodealkylation are described in DE 1668719 A1 and include a temperature of 600-800°C, an overpressure of 3-10 MPa and a reaction time of 15-45 s. The process conditions used in the preferred catalytic hydrodealkylation preferably include a temperature of 500-650°C, an overpressure of 3.5-7 MPa and a mass flow rate of 0.5-2 h ^-1 ; also see Handbook of Commercial Catalysts: Heterogeneous Catalysts ed. (Handbook of Industrial Catalysts: Heterogeneous Catalysis) ed. Howard F. Rase (2000) at cit.

Typically, the hydrodealkylation product stream is separated into a liquid stream (containing benzene and other aromatic hydrocarbons) and a gaseous stream (containing hydrogen, H2S, methane and other high boiling point hydrocarbons) using a combination of cooling and distillation. The liquid stream can be further separated by distillation into a benzene stream, a C7-C9 aromatics stream, and a heavy aromatics stream. The C ₇ -C ₉ aromatics stream, or some portion thereof, can be fed back to the reactor section as a recycle stream to increase overall conversion and benzene yield. The heavy aromatic stream which contains polyaromatic molecules such as biphenyl is preferably not recycled to the reactor but may be exported as a separate product stream. The gaseous stream contains a significant amount of hydrogen and can be recycled back, by means of a recycle gas compressor, to the reactor section. A recycle gas purge can be used to control the concentration of methane and H2S in the reactant feed.

While the invention has been described in detail for purposes of illustration, it should be understood that the details are given for that purpose only, and variations of the invention may be made by those skilled in the art without departing from the spirit and scope of the invention as defined in the claims.

Additionally, it is noted that the invention relates specifically to all possible combinations of the features described here, especially preferably to those combinations of features that are given in the claims. Therefore, it can be recognized that the description gives all combinations of features related to the composition according to the invention; all combinations of features related to the method according to the invention, and all combinations of features related to the composition according to the invention and features related to the method according to the invention.

It is further noted that the term 'comprising' does not exclude the presence of other elements. However, it should also be understood that the description of a product/composition containing certain components also discloses a product/composition consisting of these components. A product/composition consisting of these components may be advantageous in that a simpler, more economical way to obtain the product/composition is offered. Likewise, it should also be understood that a description of a process that includes certain steps also discloses a process consisting of those steps. The process consisting of these steps may be advantageous in that a simpler, more economical process is provided.

The invention is now explained with the help of the following examples, however without limiting the invention to these examples.

Catalyst Synthesis Examples

In the examples described in the invention, the term zeolite extrudates refers to ZSM-5 extrudates (CBV 5524G CY (1.6), obtained from Zeolyst International) formed from approximately 80 wt.% ZSM-5 zeolite powder having a molar ratio of silica ( SiO ₂ ) to alumina (Al ₂ O ₃ ) about 50, and about 20 wt.% Al ₂ O ₃ as a binder. Directly obtained extrudates were prepared by extrusion and subsequent heat treatment and cooling. The directly produced ZSM-5 extrudates were in the H-form and contained <0.05 wt% Na ₂ O.

Preparation of a standard catalyst.

Standard Catalyst A.

The directly obtained ZSM-5 extrudates (110 g) were pre-dried in air at 150° C. overnight (15 h) and cooled to room temperature in a desiccator.

An aqueous 0.005M solution (82.1 g) of H ₂ PtCl ₆ .6H ₂ O was diluted in a flask with deionized water (205 g) and heated to 60°C. 100 g of pre-dried ZSM-5 extrudates are added to the solution and the flask is sealed. The extrudates in solution are stirred slowly (using a magnetic stirrer) at 60° C. for 24 hours; then the liquid is decanted.

The extrudates are then washed with a large volume of water (5 l). Additionally, the extrudates are washed with 1 l of water with stirring and isolated.

The extrudates are heated in air by raising the temperature (2°/min) from room temperature to 90°C, held for 15 h at 90°C, and then raised from 90°C (at a rate of 3°/min) to 280°C and incubated for 6 hours Using the method described above, many samples of catalysts were prepared, and the content of Pt and the average data on the characteristics of the catalyst are given in table. 2.

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Catalyst Example B. Savings in (iii) impregnation, (iv) rinsing, and (v) heat treatment.

The extrudates (10 g) are air dried at 300° C. for 2 hours (raising the temperature at a rate of 2°/min from room temperature to 300° C.) and the dried extrudates are used immediately after cooling.

An aqueous 0.005M solution (8.21 g) of H ₂ PtCl ₆ .6H ₂ O was diluted with deionized water (20.5 g). 10 g of pre-dried ZSM-5 extrudates are added to the solution at room temperature and the flask is sealed. The extrudates in solution are stirred slowly (using a magnetic stirrer) at room temperature for 1 hour and then the liquid is decanted.

The extrudates are then placed in a funnel filled with 50 ml of water and water is added dropwise at a constant rate (100 ml/h).

The extrudates are calcined in air, raising the temperature at a rate of 2°/min from room temperature to 90°C, holding for 3 hours at 90°C, and then raising the temperature at a rate of 3°/min from 90°C to 280°C and holding for 2 hours .

Catalyst Example C. Savings in (ii) drying, (iii) impregnation, (iv) rinsing, and (v) heat treatment.

The extrudates are used without any pre-drying.

An aqueous 0.005M solution (8.21 g) of H ₂ PtCl ₆ .6H ₂ O was diluted in a flask with deionized water (20.5 g) and heated to 60°C. The directly obtained ZSM-5 extrudates (10 g) are added to the solution and the flask is sealed. The extrudates are slowly mixed in solution (using a magnetic stirrer) at room temperature for 1 hour and then the liquid is decanted. The extrudates are then placed in a funnel filled with 50 ml of water and water is added dropwise at a constant rate (100 ml/h).

The extrudates are calcined in air, raising the temperature at a rate of 2°/min from room temperature to 90°C, holding for 3 hours at 90°C, and then raising the temperature at a rate of 3°/min from 90°C to 280°C and holding for 2 hours .

Catalyst Example D. Savings in (ii) drying, (iii) impregnation, (iv) rinsing, and (v) heat treatment.

The extrudates are used without any pre-drying.

An aqueous 0.005M solution (8.21 g) of H ₂ PtCl ₆ .6H ₂ O was diluted in a flask with deionized water (20.5 g) and heated to 60°C. The directly obtained ZSM-5 extrudates (10 g) are added to the solution and the flask is sealed. The extrudates are slowly mixed in solution (using a magnetic stirrer) at room temperature for 1 hour and then the liquid is decanted. The extrudates are calcined in air, raising the temperature at a rate of 2°/min from room temperature to 90°C, holding for 3 hours at 90°C, and then raising the temperature at a rate of 3°/min from 90°C to 280°C and holding for 2 hours .

Table 1. Savings in steps (ii)-(v) compared to standard catalyst

Catalyst (i) drying (iii) impregnation (iv) rinsing (v) heating IN energy, time material (water), time energy, time WITH energy, time energy, time material (water), time energy, time D energy, time energy, time material (water), time energy, time

Catalyst testing.

Referring to examples 1-4, the catalysts described in this application were tested in a hydrocracking process using a stainless steel tubular reactor, which is described below. The catalyst (0.10 g, particle size 0.42-0.84 mm /20-40 mesh/) is diluted to 3 ml by mixing with SiC (30 grit) and loaded into the reactor.

Reactor description: tube 1/4 in. (6.35 mm), wall thickness 0.028 in. (0.71 mm); thermocouple 1/16 in. (1.6 mm) with spacer 1/8 in. (3.2 mm); brass casing 12x1 inch; a bed of catalyst in the reactor about 5-6 inches long at the center of the shroud.

Catalyst preactivation (drying, Pt reduction), hydrocracking feed stream composition and reactor conditions are described in Examples 1-4.

In all experiments, the mass flow rate was adjusted to achieve a benzene purity of 99.82 wt% (benzene/benzene plus C ₆ non-aromatics) in the product stream.

Example 1 Catalyst A, weight 0.10 g.

Pre-treatment of the catalyst: (a) drying: in a stream of 40 ml/min H ₂ at an overpressure of 350 kPa (50 psi), at 130°C for 2 h; (b) post-treatment with H2S: 40 ml/min H ₂ (with 50 ppm H2S) at 350 kPa at 350° C. for 30 min.

The composition of the hydrocarbon feed: 70.0 wt.% benzene, 15.0 wt.% 3-methylpentane, 15.0 wt.% methylcyclopentane. The hydrocarbon feed rate varied from 20.6 to 24.7 μl/min, which corresponds to operation at a mass flow rate of 9.9 to 11.9 h ^-1 . The flow rate of H ₂ (+H ₂ S) was varied, maintaining the molar ratio of H ₂ /hydrocarbons from 4 to 1, and the content of H2S 50 ppm. for all raw materials.

Catalyst bed temperature 470°C, overpressure 1.4 MPa (200 psi).

Example 2 Catalyst B, weight 0.10 g.

Catalyst pre-treatment: as described in example 1.

The composition of the hydrocarbon feedstock and its supply: as described in example 1.

- 10 041286

The hydrocarbon feed rate varied from 18.5 to 22.7 μl/min, which corresponds to operation at a mass flow rate of 8.9 to 10.9 h ^-1 .

The flow rate of H ₂ (+H ₂ S) was varied as described in example 1.

The temperature in the catalyst bed is 470°C, the overpressure is 1.4 MPa.

Example 3 Catalyst C, weight 0.10 g

Catalyst pre-treatment: as described in example 1

The composition of the hydrocarbon feedstock and its supply: as described in example 1.

The hydrocarbon feed rate varied from 18.9 to 22.7 μl/min, which corresponds to operation at a mass flow rate of 9.1 to 10.9 h ^-1 .

The flow rate of H ₂ (+H2S) was varied as described in Example 1.

The temperature in the catalyst bed is 470°C, the overpressure is 1.4 MPa.

Example 4 Catalyst D, weight 0.10 g

Catalyst pre-treatment: as described in example 1.

The composition of the hydrocarbon feedstock and its supply: as described in example 1.

The hydrocarbon feed rate varied from 18.9 to 22.7 μl/min, which corresponds to operation at a mass flow rate of 9.1 to 10.9 h ^-1 .

The flow rate of H ₂ (+H2S) was varied as described in Example 1.

Temperature in the catalyst bed 470°C, pressure 1.4 MPa.

Table 2. Influence of the method of preparation on the characteristics of the catalyst

Example Catalyst Pt, wt.% purity of benzene wt.% mass flow rate, h ¹ %C in the output stream benzene methane light HC ¹ amount of aromatics 1 A 0.066 99.82 11.16 60.89 1.21 34.15 65.74 2 IN 0.0808 99.82 9.06 62.11 1.24 33.16 66.68 3 WITH 0.0758 99.82 9.72 59.89 1.13 35.79 64.10 4 D 0.0711 99.82 9.68 60.06 1.19 35.19 64.68

¹ Light HC = hydrocarbons C1-C ₅ .

It can be seen that the catalyst prepared according to the invention (B, C, D) exhibits comparable performance to the catalyst prepared by the time consuming procedures (A).

Below are some embodiments of the methods disclosed in the invention.

Embodiment 1: a method for producing a hydrocracking catalyst, comprising: (i) obtaining a molded body containing a zeolite and a binder, where the molded body is obtained by molding, calcining and cooling, and the zeolite is ZSM-5 having a molar ratio of silicon dioxide (SiO ₂ ) to aluminum oxide (Al ₂ O ₃ ) 25-75; (ii) optionally drying the molded mass at a temperature of 100-300° C. for a period of at least 1 hour; (iii) depositing the hydrogenating metal on the molded mass by impregnation over a period of at least 2 hours so that the amount of hydrogenating metal is 0.010-0.30 wt.%, based on the entire catalyst; (iv) optionally washing the deposited metal shaped body with water; and (v) heat treating the molded mass with the deposited metal in air at a temperature of 250-300° C. for a period of 1-5 hours; where the catalyst has a total content of sodium and cesium is less than 0.05 wt.% based on the total weight of the catalyst.

Embodiment 2. The method of Embodiment 1, wherein the method does not include step (ii).

Embodiment 3. The method of any one of the preceding embodiments, wherein the method does not include step (iv).

Embodiment 4. The method according to any one of the preceding embodiments, wherein step (v) is carried out at a temperature of 270-290°C for 1-3 hours.

Embodiment 5. The method according to any one of the preceding embodiments, wherein the catalyst contains a total of less than 0.05 wt.% alkali or alkaline earth metal, preferably less than 0.04 wt.%, or less than 0.01 wt.%, based on the total weight of the catalyst.

Embodiment 6. The method of Embodiment 1 wherein the zeolite has a silica (SiO ₂ ) to alumina (Al ₂ O ₃ ) mole ratio of 30-65, preferably 35-60, more preferably 40-55.

Embodiment 7. A process according to any one of the preceding embodiments, wherein the amount of hydrogenating metal is 0.015-0.095 wt.%, preferably 0.0350.080 wt.%, or 0.040-0.075 wt.%, based on the total catalyst.

Embodiment 8 The method of any one of the preceding embodiments wherein the hydrogenating metal is platinum.

Embodiment 9. The method according to any one of the preceding embodiments, wherein the hydrocracking catalyst contains 0.01 parts of bismuth, preferably contains

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Claims (7)

less than 0.01 parts of tin, less than 0.02 parts of lead, less than 0.01 parts of bismuth, and less than 0.01 parts of molybdenum (based on 100 parts by weight of the entire catalyst). Embodiment 10. A process according to any one of the preceding embodiments wherein the amount of binder in the hydrocracking catalyst is 10-50% by weight based on the total catalyst. Embodiment 11. The method of any one of the preceding embodiments wherein the hydrocracking catalyst is an extrudate having an average diameter of 0.115 mm. Embodiment 12. The process of any one of the preceding embodiments, wherein the catalyst contains less than 0.04% by weight of sodium and cesium in total, or less than 0.01% by weight based on the total weight of the catalyst. Embodiment 13. The method of any one of the preceding embodiments wherein no alkali or alkaline earth metals are added to the zeolite. Embodiment 14. The method of any one of the preceding embodiments wherein the zeolite is in hydrogen form. Embodiment 15. The method of any one of the preceding embodiments wherein the zeolite is not exchanged with a base. Embodiment 16. The method of any one of the preceding embodiments wherein the zeolite is not ion exchanged with any metal from Group IA or Group IIA of the Periodic Table of the Elements. Embodiment 17. A process for producing BTX, comprising: (a) obtaining a hydrocracking feed stream containing C ₅ -C ₁₂ hydrocarbons; (b) contacting the hydrocracking feed stream in the presence of hydrogen with a hydrocracking catalyst obtained using the process of any of the preceding embodiments under process conditions comprising a temperature of 425-580° C., an overpressure of 300-5000 kPa, and a mass flow rate of 3-30 h ^-1 , with the formation of the stream of hydrocracking product containing BTX; and (c) separating BTX from the hydrocracked product stream. Embodiment 18. The process of Embodiment 17, wherein the hydrocracking feed stream comprises a fresh feed stream that is first stage or multi-stage hydrotreated pyrolysis gasoline, straight-run naphtha, hydrocracked gasoline, light coking naphtha and coke oven light gas oil, FCC gasoline, product a reformer or a mixture thereof, which is optionally subjected to a treatment such as hydrogenation, enrichment in monoaromatic compounds and/or removal of pentanes, and optionally a recycle stream from the hydrocracked product stream. Embodiment 19. The process of any one of Embodiments 17-18, wherein the hydrocracking feed stream is produced by a process that does not include a benzene removal step. Embodiment 20. The process of any one of Embodiments 17-19 wherein the hydrocracking feed stream contains 10-90 wt % benzene. CLAIM 1. A method for producing a hydrocracking catalyst, consisting of the following successive stages: (i) obtaining an extrudate consisting of a zeolite and a binder, and the extrudate is obtained by shaping, calcining and cooling, where the zeolite is ZSM-5 having a molar ratio of silicon dioxide (SiO ₂ ) to alumina (A12O3) equal to 25- 75 and the binder is alumina; (ii) depositing the hydrogenating metal, which is Pt, on the extrudate by impregnation with an aqueous solution of H ₂ PtCl ₆ .6H ₂ O for 0.5 to 1.5 hours so that the amount of the hydrogenating metal is 0.015-0.095 wt.%. based on the entire catalyst; (iii) heat treatment of the metal-deposited extrudate in air at a temperature of 270-290°C for a period of 1-3 hours, with no drying of the extrudate after step (i) and before step (ii) at a temperature of 100-300°C in for a period of 1 hour; and washing the precipitated metal extrudate with water after step (ii) and before step (iii), the catalyst containing a total of less than 0.05 wt. % sodium and cesium. 2. The method according to claim 1, wherein the catalyst contains a total of less than 0.05 wt.% alkali or alkaline earth metal, preferably less than 0.04 wt.% or less than 0.01 wt.% based on the total weight of the catalyst. 3. The method according to claim 1, wherein the zeolite has a silica (SiO ₂ ) to alumina (A12O3) molar ratio of 30-65, preferably 35-60, more preferably 40-55. 4. Process according to any one of claims 1 to 3, wherein the amount of hydrogenating metal is 0.0350.080% by weight based on the total catalyst. - 12 041286 5. The process according to any one of claims 1 to 4, wherein the hydrocracking catalyst contains less than 0.01 parts of tin, less than 0.02 parts of lead, less than 0.01 parts of bismuth and less than 0.01 parts of molybdenum in terms of per 100 parts by weight of the total catalyst. 6. Process according to any one of claims 1 to 5, wherein the amount of binder in the hydrocracking catalyst is 10-50% by weight, based on the total catalyst. 7. A process according to any one of claims 1 to 6, wherein the hydrocracking catalyst is an extrudate having an average diameter of 0.1-15 mm. Eurasian Patent Organization, EAPO Russia, 109012, Moscow, Maly Cherkassky per., 2 -