RU2434053C2 - Procedure for production of hydrocarbons fractions - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: invention refers to procedure of production of hydrocarbon fractions including stage of catalytic hydro-cracking of source hydrocarbon compounds containing poly-cyclic aromatic hydrocarbons and where ratio of carbon atoms forming aromatic cycle is as high, as mole 35 %. Also, the said ratio corresponds to a share of carbon atoms forming aromatic cycles in total amount of carbon atoms in oil at presence of hydrogen with purpose of conversion of not less, than 40 % of fractions with boiling temperature as high, as 215°C into fractions, boiling temperature of which is less, than 215°C. Thus, there is produced oil subjected to hydro-cracking containing 30 vol. % or more of mono-cycle aromatic hydrocarbons.

EFFECT: production of light hydrocarbons and simultaneously efficient and selective production of mono-cyclic aromatic hydrocarbon corresponding to alkyl-benzenes of high value.

8 cl, 57 ex, 10 tbl

Description

FIELD OF THE INVENTION

The present invention relates to a method for producing fractions of various hydrocarbons by hydrocracking specific petroleum oils containing polycyclic aromatic hydrocarbons. In particular, the present invention relates to a method for producing hydrocarbon fractions by preparing hydrocracked liquid petroleum products that selectively contain a large amount of monocyclic aromatic hydrocarbons, and then producing light hydrocarbon fractions such as a liquefied petroleum gas (LPG) fraction, a gasoline fraction, kerosene fraction, fraction of light diesel fuel, non-aromatic ligroin fraction and monocyclic aromatic hydrocarbon.

State of the art

In recent years, there has been a marked increase in demand for lighter petrochemical products, in particular petrochemical feedstocks represented by BTX hydrocarbons (benzene, toluene and xylene). In addition, in addition to BTX hydrocarbons, aromatic hydrocarbons, due to their high octane number, are widely used as components for formulating gasoline compositions. The liquid catalytic cracking method can be an example of a method for producing fractions containing monocyclic aromatic hydrocarbons that are represented by BTX hydrocarbons. Although this method allows you to obtain approximately 50 vol.% Ligroin fraction, the content of monocyclic aromatic hydrocarbons in the ligroin fraction is a maximum of approximately 20%, and the content of hydrocarbons BTX is less than 10%. The catalytic reforming process can also be an example of a process for the selective production of aromatic hydrocarbons. However, the starting materials for the catalytic reforming process are limited to ligroin fractions having the same boiling range, so their number is limited. For this reason, in order to increase the variety of starting materials and obtain cheaper raw materials, a method for producing monocyclic aromatic hydrocarbons from fractions heavier than BTX is needed.

In addition to the method of liquid catalytic cracking, a method of producing vacuum gas oil hydrocracking is widely used as a method for producing light petroleum oils by cracking heavy petroleum oils. In the vacuum gas oil hydrocracking method, the desired fractions are obtained by forcing the starting materials into contact with the catalyst at high temperature in the presence of gaseous hydrogen under high pressure. These methods used to be usually used only to obtain fractions such as light diesel fuels and jet fuels, the boiling point of which is in the range from about 150 to 370 ° C. Thus, a method of obtaining a product that has the required properties for use as light diesel fuel or jet fuel, i.e. a method that allows to achieve the lowest possible content of aromatic substances.

On the other hand, with regard to various petroleum intermediates that are obtained from oil refining processes, due to both regional and international environmental requirements, there is a tendency to reduce the consumption of fractions with a high sulfur content or high aromatic content as fuel components . For example, since the fraction of light diesel fuel, also called light catalytic cracking oil (LCO), which is obtained by liquid catalytic cracking, or the fraction of light diesel fuel, which is obtained by thermal cracking, contain a large amount of sulfur or contain a large amount of polycyclic aromatic substances, then these fractions, when used as diesel fuel, emit sulfur oxide or particles. Thus, the preparation of compositions using large quantities of these fractions causes difficulties.

Patent Document 1 describes the use of LCO and similar substances as raw materials for use in a hydrocarbon conversion reaction. However, the proposed method is simply a method for producing light diesel fuel and kerosene. Patent Document 1 does not describe the preparation of aromatic compounds represented by BTX hydrocarbons. Patent Document 2 discloses a method for treating aromatic hydrocarbons with hydrogen in order to reduce the amount of particles formed during combustion. However, the object of the method is to obtain linear hydrocarbons by reducing the content of aromatic substances. Patent Document 3 discloses a process for the hydrogenation of polycyclic aromatic compounds using a solid catalyst. The aim of the method is to obtain light diesel fuel having an improved cetane number. This method is not a technological method that allows to reduce the molecular weight of polycyclic aromatic compounds and to turn the compounds into raw materials suitable even for petrochemical processes. Patent Documents 4 and 5 provide methods for producing gasoline fractions by hydrocracking LCO fractions. The purpose of these methods is to control the rate of conversion to gasoline fractions under relatively mild reaction conditions so that a certain number of fractions of light diesel fuel is retained. Patent Document 6 discloses a method for producing kerosene fractions, light diesel fractions and naphtha fractions by hydrocracking a mixture of LCO and VGO fractions (vacuum gas oil). The main objective of the method is to obtain kerosene fractions and fractions of light diesel fuel. The predominant production of BTX hydrocarbons is not provided.

Patent Document 7 discloses a method for reducing the molecular weight of heavy aromatic hydrocarbons containing nine or more carbon atoms, but the number of aromatic cycles is not indicated. The difficulty of converting aromatic hydrocarbons having two or more cycles into monocyclic aromatic hydrocarbons is not discussed. Non-patent document 1 proposes a method for the partial production of BTX hydrocarbons using LCO as a feedstock. However, the object of the method is to obtain diesel fuel and gasoline. It is not a method of predominantly obtaining BTX. Non-patent document 2 also discloses a method for producing high octane gasoline by hydrocracking 1-methylnaphthalene, which is a bicyclic aromatic hydrocarbon, contained in large quantities in LCO fractions. However, since the reaction produces a large amount of cycloparaffins and isoparaffins, the octane number of the product remains low at approximately 85. Thus, this method is not a method for the selective production of monocyclic aromatic hydrocarbons.

As indicated above, despite the many disclosed methods for producing naphthenes by hydrogenation of aromatic nuclei of polycyclic aromatic hydrocarbons or methods for partial hydrogenation of aromatic nuclei of polycyclic aromatic hydrocarbons, methods have not been developed for the selective preparation of alkyl benzenes represented by the BTX fraction using heavy hydrocarbons as starting compounds.

[Patent Document 1] JP-A-2004-148314

[Patent Document 2] JP-A-H08-183962

[Patent Document 3] JP-A-2000-226589

[Patent Document 4] Japanese Patent No. 3001963

[Patent Document 5] JP-B-H03-170598

[Patent document 6] WO 2006/062712

[Patent Document 7] Japanese Patent No. 3302553

[Non-patent document 1] Thakkar et a., National Petrochemical & Refiners Association, Annual Meeting, AM-05-53 (2005)

[Non-patent document 2] Demirel et al., Fuel, Vol. 77, No.4, p. 301-311 (1998)

Description of the invention

Problems to be Solved by the Present Invention

In connection with the foregoing, an object of the present invention is to provide a method for producing at least two hydrocarbon fractions selected from an LPG fraction, a gasoline fraction, a kerosene fraction, a light diesel fuel fraction, a monocyclic aromatic hydrocarbon fraction and a non-aromatic naphtha fraction from a hydrocracked oil by hydrocracking a hydrocarbon fraction containing polycyclic aromatic hydrocarbons in order to convert them into light hydrocarbon fractions, avoiding volume of such problems as coking, and at the same time obtaining, with high efficiency and selectivity, monocyclic aromatic hydrocarbons, which are alkylbenzenes of greater value.

Means for solving these problems

As a result of intensive studies, the authors of the present invention found that aromatic hydrocarbons represented by alkylbenzenes and fractions of various light hydrocarbons can be obtained with high yield due to the choice of the type of carbon structures constituting the initial hydrocarbon compounds used in the hydrocracking, and process conditions , as well as due to strict control of hydrogenation and cracking activity in the process of hydrocracking. This discovery led to the development of the concept of a method for producing hydrocarbon fractions of the present invention.

In particular, the present invention is a method as described below.

(1) A method for producing hydrocarbon fractions, comprising the step of catalytic hydrocracking of starting hydrocarbon compounds that contain polycyclic aromatic hydrocarbons and in which the ratio of carbon atoms forming the aromatic cycle is not less than 35 mol%, wherein said ratio is the fraction of carbon atoms forming aromatic cycles in the total number of carbon atoms in oil, in the presence of hydrogen, with the aim of converting at least 40% of the fractions whose boiling point is nent is not less than 215 ° C, the fraction boiling point of less than 215 ° C, and producing hydrocracked petroleum oil containing 30 vol.% or more of the monocyclic aromatic hydrocarbon.

(2) The method according to (1), wherein the operating conditions at the hydrocracking stage are pressure, which is from 2 to 10 MPa, temperature, which is from 200 to 450 ° C, hourly volumetric rate of liquid (LHSV), which is from 0.1 to 10.0 h ^-1 , the hydrogen / oil ratio, which is from 100 to 5000 nl / l, and the fraction of residual carbon of the aromatic rings, which is the ratio of the fraction of carbon atoms forming the aromatic cycle, in the hydrocracked oil to fraction of carbon atoms forming an aromatic cycle in the starting angle hydrogen compounds is not less than 0.5.

(3) The method according to (1) or (2), wherein the hydrocarbon feeds are petroleum oil fractions obtained from a catalytic cracking unit, thermal cracking unit, ethylene cracking unit, supercritical liquid cracking unit, or thermal reforming unit, or a mixture of two or more amounts of said petroleum oil fractions.

(4) The method according to any one of (1) to (3), wherein the distillation characteristics of the starting hydrocarbon compounds are such that 10 vol.% Of the distillate has a boiling point in the range of 140 to 230 °, and 90 vol.% Of the distillate has a temperature boiling range from 230 to 600 °.

(5) The method according to any one of paragraphs (1) to (4), which further comprises a separation step, in order to obtain at least two hydrocarbon fractions selected from an LPG fraction, a gasoline fraction, a kerosene fraction, a light diesel fraction , non-aromatic ligroin fractions and fractions of monocyclic aromatic hydrocarbons from hydrocracked oil, which is obtained by hydrocracking.

(6) The method according to any one of paragraphs (1) to (5), wherein the hydrocracking catalyst comprises a carrier which is a mixed oxide and a binder that combines the mixed oxide and at least one metal selected from Group VI metals and metals of group VIII of the periodic table of elements and deposited on a carrier, and has the following properties: specific surface area from 100 to 800 m ² / g, average pore diameter from 3 to 15 nm, and pore volume occupied by pores with a diameter from 2 to 60 nm is from 0.1 to 1.0 ml / g.

(7) The method according to (6), wherein the mixed oxide comprises at least one of mixed silicon and aluminum oxides, mixed silicon and titanium oxides, mixed silicon and zirconium oxides, mixed silicon and magnesium oxides, mixed silicon oxides, aluminum and titanium, mixed oxides of silicon, aluminum and zirconium, tungsten-containing zirconium oxide, sulfated zirconium oxide and zeolite.

(8) The method according to (6), wherein the binder comprises at least one of alumina, mixed silica and aluminum, and mixed boron and aluminum oxide.

The effect of using the invention

In accordance with the method for producing hydrocarbon fractions of the present invention, hydrocarbon fractions having high boiling points are converted to hydrocarbon fractions having low boiling points, and, in addition, when using petroleum oil containing a large amount of polycyclic aromatic hydrocarbons as raw material, and contacting the oil with an optimal hydrocracking catalyst in the presence of hydrogen in such a way as to prevent catalyst poisoning, with a greater formed with high yield value alkylbenzenes (the monocyclic aromatic hydrocarbons) represented BTX fraction. In addition, since a hydrocracking catalyst is used that is most suitable for hydrocracking and has a predetermined composition and desired properties that are suitably balanced in terms of hydrocracking activity and hydrogenation activity, gas generation due to excessive cracking can be controlled, and the decrease in activity caused by coking due to coking due to hydrogenation deficiency can be suppressed. In addition to the ability to produce alkylbenzenes in high yield and with high selectivity, it is possible to obtain an LPG fraction, a gasoline fraction, a kerosene fraction, a light diesel fuel fraction, a non-aromatic ligroin fraction and a monocyclic aromatic hydrocarbon fraction by separating the hydrocracked oil using a suitable known method. These fractions can be effectively used as products for formulating LPG compositions with low sulfur content, products for composing compositions of high octane gasoline with low sulfur content, products for composing compositions of kerosene with low sulfur content, products for composing compositions of light diesel fuel with high cetane number and low sulfur, products for the preparation of compositions of non-aromatic naphtha with low sulfur, as well as raw materials for petrochemicals eskogo synthesis and used to reduce the load on the environment.

BEST MODE FOR CARRYING OUT THE INVENTION

The term “polycyclic aromatic hydrocarbons” as used in the present invention refers to hydrocarbons having two or more aromatic rings, and the term “monocyclic aromatic hydrocarbon” refers to compounds whose hydrogen atoms are not substituted with 0 to 6 chain hydrocarbon groups, and the so-called "alkylbenzenes". The term “1,5-cyclic aromatic hydrocarbons” refers to compounds having one aromatic cycle and one saturated naphthalene cycle in a molecule, such as tetralin (1,2,3,4-tetrahydronaphthalene) and indane (2,3-dihydroindene).

The method for producing the hydrocarbon fractions of the present invention will be further described in more detail in the following order: feedstock for the hydrocracking reaction, pretreatment step, hydrocracking reaction, hydrocracking catalyst, method for producing a hydrocracking catalyst, oil refining method for hydrocracked petroleum oil and resulting hydrocarbons.

[Raw materials for hydrocracking reaction]

Petroleum oil, which is used to carry out the hydrocracking reaction of the present invention, contains polycyclic aromatic hydrocarbons. In petroleum oil, the ratio of carbon atoms forming aromatic cycles to the total number of carbon atoms in petroleum oil (ratio of carbon atoms forming aromatic cycle) is not less than 35 mol%, preferably not less than 40 mol%, and most preferably , not less than 45 mol.% If the ratio of carbon atoms forming aromatic rings to the total number of carbon atoms is less than 35 mol%., then the required monocyclic aromatic hydrocarbons (alkylbenzenes) cannot be obtained in high yield. The ratio of carbon atoms forming the aromatic cycle can be calculated by analyzing ¹³ C-NMR using a nuclear magnetic resonance spectrometer (NMR).

As for the number of aromatic cycles, it no longer means better. From the point of view of obtaining predominantly monocyclic aromatic hydrocarbons, the preferred polycyclic hydrocarbons in the feed are bicyclic aromatic hydrocarbons. Particularly preferred is a feedstock containing a small amount of tricyclic or polycyclic aromatic hydrocarbons having a larger number of cycles and a large amount of 1,5-cyclic and 2-cyclic aromatic hydrocarbons. The amount of tricyclic or polycyclic aromatic hydrocarbons having a larger number of cycles is preferably 5.0 vol% or less, more preferably 3.0 vol% or less, and most preferably 1.0 vol% or less; and the amount of bicyclic or polycyclic aromatic hydrocarbons having a larger number of cycles is preferably 10 vol% or more, more preferably 20 vol% or more, and most preferably 30 vol% or more. Preferably, a feedstock is used that contains 50 vol.% Or more, more preferably 60 vol.% Or more, and most preferably 70 vol.% Or more aromatic hydrocarbons, while aromatic hydrocarbons with less than three cycles are mainly used ( total amount of monocyclic, 1,5-cyclic and 2-cyclic aromatic hydrocarbons).

Preferred distillation characteristics can be determined based on the above aromatic compositions. In particular, if we take into account the boiling point (218 ° C) of a bicyclic aromatic hydrocarbon naphthalene, then at least the content of fractions with a boiling point in the range from 215 to 280 ° C is 10 vol.% Or more, and the content of fractions with a boiling point of 215 ° C. or higher is 30 vol.% or more and, more preferably, is 40 vol.% or more. Thus, as preferred distillation properties of the starting compounds, 10% of the distillate has a boiling point of from 100 to 230 ° C., more preferably, has a boiling point of from 140 to 230 ° C. and, even more preferably, has a boiling point of from 150 to 220 ° C, and 90% of the distillate has a boiling point of 230 to 600 ° C, more preferably has a boiling point of 230 to 400 ° C, even more preferably has a boiling point of 230 to 310 ° C, and most preferably has a boiling point from 265 to 300 ° C.

As inhibitors of the hydrocracking reaction, the feedstock for carrying out the hydrocracking reaction usually contains from 0.1 to 3000 mass ppm. nitrogen and from 0.1 to 3 wt.% sulfur. Basic sulfur compounds include benzothiophenes, dibenzothiophenes and sulfides. In the range of boiling temperatures of the feedstock, which is used according to the present invention, benzothiophenes and dibenzothiophenes fall in large quantities. Since it is known that dibenzothiophenes, due to the structure with delocalized electrons, are stable compounds and are difficult to react, the feedstock used in accordance with the present invention should preferably not contain too much dibenzothiophene.

As a petroleum oil containing polycyclic aromatic hydrocarbons that are used to carry out the hydrocracking reaction of the present invention, any petroleum oil can be used, provided that the ratio of carbon atoms forming the aromatic cycle to the total number of carbon atoms in the oil (fraction of carbon atoms forming an aromatic cycle) is 35 mol.% or more, and petroleum oil contains 30 vol.% or more fractions, the boiling point of which is 215 ° C or more.

In particular, fractions obtained by atmospheric distillation of crude oil, vacuum gas oil, obtained by vacuum distillation of residues formed at atmospheric pressure, distillates obtained during cracking of various heavy oils (from a catalytic cracking unit, from a thermal cracking unit, and etc.), such as catalytic cracking oil (in particular LCO) obtained from a catalytic cracking unit and thermal cracking oil obtained from a mouth thermal cracking tubes (coking plants, cracking furnaces for light cracking, etc.), heavy residues from the ethylene cracking unit, catalytic reformate obtained from the catalytic reforming unit, catalytic reformate enriched in aromatic compounds obtained from the catalytic reformate using the following extraction, distillation or separation on membranes (the term “aromatic enriched catalytic reformate” in the present description refers to fractions obtained m as a result of catalytic reforming and including aromatic compounds with 10 or more carbon atoms that contain 50 vol.% or more aromatic compounds), fractions obtained after the aromatic compounds extraction process, in order to obtain a basic lubricating oil, fractions enriched in aromatic compounds, obtained as a result of the process of paraffinization using solvents, and the like. Preferably, other hydrocarbon fractions resulting from a desulfurization process or a hydroconversion process (for example, heavy oil after a cracking process such as an oil oil process and an OCR process, as well as after a cracking process of a supercritical liquid for heavy oil) can also be used, with which carry out oil refining of residues obtained by atmospheric distillation, obtained by vacuum distillation of residues, clarified oil, oil sand, shale, coal and biome ssy.

As a hydrocarbon source for the hydrocracking reaction, distillates obtained in one or more of the above reforming units in any arbitrary order can also be used. These hydrocarbon sources can be used individually or in combination with two or more others to such an extent that the above range of the boiling point and the ratio of carbon atoms forming the aromatic cycle satisfy the determination of the hydrocarbon source for the hydrocracking reaction. Hydrocarbon sources having a boiling range and also having a ratio of carbon atoms forming an aromatic cycle that are outside the above range can also be used by correcting so that the boiling range and the ratio of carbon atoms forming an aromatic cycle are inside the above range. Among the aforementioned hydrocarbon sources, catalytic cracking oil, thermal cracking oil, vacuum gas oil, heavy ethylene cracking residues, catalytic reformate and supercritical fluid decomposition oil are preferred, with light catalytic cracking oil (LCO) being most preferred.

[Pretreatment Stage]

In accordance with the present invention, polycyclic aromatic hydrocarbons are selectively converted to monocyclic aromatic hydrocarbons by hydrocracking, and in addition, polycyclic aromatic hydrocarbons can be pretreated before hydrocracking is required. As indicated above, there are many starting compounds for the hydrocracking reaction, and the content of sulfur-containing and nitrogen-containing compounds that are present in the starting compounds is also diverse. The hydrocracking catalyst cannot fully function when the concentration of sulfur-containing and nitrogen-containing compounds is too high. Thus, it is preferable to preliminarily lower the sulfur content and nitrogen content using known methods as a pretreatment step before the behavior of the hydrocracking step. As an example of a pretreatment process, catalytic desulfurization in the presence of hydrogen, adsorption separation, sorption separation, oxidation and the like can be cited. Among them, catalytic desulfurization in the presence of hydrogen is most preferred. In the case of using the catalytic desulfurization method in the presence of hydrogen, the feedstock for carrying out the hydrocracking reaction is introduced into the interaction with the oil refining catalyst in the presence of hydrogen, preferably at a temperature of from 150 to 400 ° C, more preferably at a temperature of from 200 to 380 ° C and even more preferably, at a temperature of from 250 to 360 ° C., preferably under a pressure of from 1 to 10 MPa, and more preferably, under a pressure of from 2 to 8 MPa, wherein the hourly space velocity of the liquid (LHSV) is preferably from 0.1 to 10.0 h ⁻¹ , more preferably 0.1 to 8.0 h ^−1, and even more preferably 0.2 to 5.0 h ⁻¹ , wherein the hydrogen / petroleum oil, preferably, is from 100 to 5000 nl / l, and even more preferably, is from 150 to 3000 nl / l.

Due to the above processing, the sulfur content is reduced, preferably up to 500 mass ppm. or less, more preferably up to 100 mass ppm. or less and, most preferably, up to 50 mass ppm or less; and the nitrogen content is reduced, preferably, to 50 mass ppm. or less, more preferably up to 20 mass ppm. or less and, most preferably, up to 10 mass ppm Along with the catalytic oil refining carried out due to the above desulfurization and denitrification in the presence of hydrogen, aromatics can also partially hydrogenate. According to the present invention, reducing the amount of polycyclic aromatic hydrocarbons does not cause problems, however, it is undesirable to reduce the amount of monocyclic aromatic hydrocarbons. Therefore, it is preferable to carry out the treatment under reaction conditions under which hydrogenation can be stopped when the polycyclic aromatic hydrocarbons are hydrogenated to monocyclic or 1,5-cyclic aromatic hydrocarbons. Up to this point, it is preferable to control the hydrogenation reaction so that the remaining amount (in terms of volume) of the total amount of aromatic hydrocarbons at the end of the reaction is 0.90 or more of the amount before the reaction, more preferably 0.95 or more, and even more preferably, was 0.98 or more.

There are no particular restrictions for the catalytic oil refining catalyst, which is used in the preliminary stage of the catalytic desulfurization in the presence of hydrogen. Preferably, a catalyst is used containing at least one metal selected from group VI or group VIII of the Periodic Table, which is supported on a refractory oxide support. As a specific example of such a catalyst, a catalyst containing at least one metal selected from molybdenum, tungsten, nickel, cobalt, platinum, palladium, iron, ruthenium, osmium, rhodium and iridium as metals of group VI or group VIII can be cited. A periodic table that is supported on a carrier, which at least is a carrier selected from alumina, silica, boron and zeolite. Catalytic oil refining catalysts are used after such treatments as drying, reduction, sulfidation and the like, which may be required before hydrogenation. The amount of catalyst in the pretreatment step is preferably 10 to 200 vol.% Of the amount of hydrocracking catalyst. If the amount of catalyst is 10 vol% or less, sulfur removal is not sufficient; on the other hand, if it is 200 vol.% or more, then a large installation will be required, which makes the process inefficient. The pre-treatment step and the hydrocracking step can be carried out in a reactor column that contains separate catalyst beds filled with a suitable catalyst, or can be carried out in separate reactor columns. To accelerate the reaction, a hydrogen supply line can be placed between the two catalyst beds, and a line for discharging the reacted gas can be installed upstream of the hydrogen supply line in order to discharge the reacted gas and introduce fresh hydrogen gas. There is no need to mention that the pre-treatment step and the hydrocracking step, respectively, can be carried out in separate plants.

[Hydrocracking reaction]

In the hydrocracking reaction of the present invention, the oil is contacted with a hydrocracking catalyst, which will be described in detail later, in the presence of hydrogen so as to convert 40% or more, preferably 50% or more of the fractions having a boiling point of 215 ° C. or higher into fractions having a boiling point of 215 ° C or lower, and thereby obtain various fractions of light hydrocarbons, including monocyclic aromatic hydrocarbons. In particular, hydrocracking oil containing 30% or more monocyclic aromatic hydrocarbons and other various fractions of light hydrocarbons is obtained from the starting hydrocarbon compounds by converting hydrocarbon fractions that have a boiling point higher than the specified boiling point for the starting hydrocarbons, in other words, by converting polycyclic hydrocarbons into monocyclic aromatic hydrocarbons (alkylbenzenes) by reducing the number of aromatic cycles of polycyclic their aromatic hydrocarbons.

Structural options for carrying out the reaction for hydrocracking of petroleum oil of the present invention are not specifically limited. Conventionally used reaction design variants may be used, such as a fixed bed, fluidized bed, fluidized bed, moving bed and the like. Among them, a reaction in a fixed bed is preferred due to the simplicity of the design of the process equipment and the ease of the process.

The hydrocracking catalyst used in the hydrocracking of the petroleum oil of the present invention is placed in a reactor and subjected to pre-treatment such as drying, reduction, sulfidation and the like before use. These pre-treatment methods are generally known to those skilled in the art and are carried out internally. the reactor column or outside the reactor column by well known methods. The activation of the catalyst by sulfidation is carried out by treating the hydrocracking catalyst in a stream from a mixture of hydrogen and hydrogen sulfide at a temperature of from 150 ° C to 800 ° C and, preferably, at a temperature of from 200 ° C to 500 ° C.

Hydrocracking conditions, such as reaction temperature, reaction pressure, hydrogen flow rate, hourly space velocity of the liquid, and the like, can be appropriately adjusted according to the properties of the starting compounds, the quality of the desired product, the volume of production, the performance of the oil refining units and pre-treatment. The starting compounds for hydrocracking are contacted with a hydrocracking catalyst in the presence of hydrogen at a temperature of from 200 to 450 ° C, more preferably at a temperature of from 250 to 430 ° C and, even more preferably, at a temperature of from 280 to 400 ° C, under a pressure of from 2 up to 10 MPa and, more preferably, under a pressure of 2 to 8 MPa with a LHSV value of from 0.1 to 10.0 hour ^-1 , more preferably equal to from 0.1 to 8.0 hour ^-1 and, even more preferably equal to from 0.2 to 5.0 hour ^-1 , while the ratio of hydrogen / petroleum oil (by volume) is in the range from 100 to 5 000 nl / l and preferably ranges from 150 to 3000 nl / l. Polycyclic aromatic hydrocarbons in the original hydrocarbon compounds used for the hydrocracking reaction are decomposed and converted to the desired monocyclic aromatic hydrocarbons (alkylbenzenes) by hydrocracking under the above conditions. Reaction conditions outside the above range are undesirable due to insufficient cracking activity, rapid catalyst degradation, and the like.

[Hydrocracking catalyst]

The hydrocracking catalyst of the present invention includes a carrier made of a mixed oxide and a binder that combines the mixed oxide and at least one metal selected from group VI and group VIII of the Periodic Table, which is supported on the carrier. The catalyst is shaped into tablets (cylindrical tablets, granules of special shapes), granules, spheres, and the like. The catalyst mainly has a specific surface, the value of which is from 100 to 800 m ² / g, an average pore diameter in the range from 3 to 15 nm and the pore volume occupied by pores with a diameter of from 2 to 60 nm, which is from 0.1 up to 1.0 ml / g.

The specific surface area is the BET specific surface area, which is determined by the method of nitrogen adsorption in accordance with ASTM D3663-78. More preferably, the specific surface area is from 150 to 700 m ² / g and, even more preferably, is from 200 to 600 m ² / g. If the specific surface of BET is less than the above range, the degree of dispersion of the active metal is insufficient and the activity does not increase. On the other hand, if the BET specific surface is larger than the above range, then a sufficient pore volume cannot be maintained, and thus, the reaction products are not dispersed enough and the development of the reaction can be quickly suppressed, which is undesirable.

The average pore diameter of the hydrocracking catalyst is more preferably 0.4 to 12 nm and most preferably 5.0 to 10 nm. The pore volume occupied by pores with a diameter of from 2 to 60 nm, more preferably, is from 0.15 to 0.8 ml / L and, most preferably, is from 0.2 to 0.7 ml / L. Since there are corresponding ranges of the average pore diameter and pore volume with respect to the size of the molecules involved in the reaction and the dispersion of the molecules, both too large and too small values of the average pore diameter and pore volume are not preferred.

Characteristics of pores, the so-called mesopores, i.e. the above pore diameter and pore volume can be measured by nitrogen gas absorption, and the ratio between pore volume and pore diameter can be calculated by the BJH method or a similar method. The average pore diameter is defined as the pore diameter corresponding to the accumulated pore volume at the moment when the accumulated pore volume is half of the total volume (V) on the storage curve for the pore volume obtained by accumulating the entire volume for pores of each pore diameter, with the total pore volume (V) represents the accumulation of pore volume occupied by pores whose diameter is in the range from 2 to 60 nm, and it is determined at a relative pressure of 0.9667 by the method of absorption of gaseous nitrogen.

Catalysts having macropores, mesopores or micropores can be used as hydrocracking catalysts of the present invention. Since the characteristics of the mesopores of the mixed oxide-based support can usually be maintained until the preparation of the catalyst, the characteristics of the mesopores of the hydrocracking catalyst can mainly be controlled by controlling the mixing conditions (time, temperature, torque) and calcination conditions (time, temperature, type and flow rate used for gas calcination) so that the mixed oxide support can have the above mesopore characteristics.

The characteristics of the macropores can be controlled by controlling the voids between the mixed oxide particles and the content of the binder. The voids between the mixed oxide particles can be controlled by the diameter of the mixed oxide particles, and the binder content can be controlled by the mixed amount of the binder.

The characteristics of micropores mainly depend on pores that are naturally present in mixed oxides, such as zeolites, but they can also be controlled by dealumination with water vapor and the like.

The properties and conditions of molding the binder, which will be discussed later, can also influence the characteristics of mesopores and macropores. To obtain a carrier, the mixed oxide is mixed with an inorganic oxide (binder) matrix.

[Mixed oxide]

The mixed oxide used in the present invention refers to a mixed oxide having solid acid properties. For example, many double mixed oxides are known in addition to mixed oxides, the acidity of which is confirmed by K.Shibata, T.Kiyoura, J. Kitawaga, K. Tanabe, Bull. Chem. Soc. Jpn., 46, 2985 (1973). Among such mixed oxides, silica-alumina, silica-titania, silica-zirconia and silica-magnesium oxide may preferably be used as the mixed oxide used in the present invention. Silica-alumina-titania and silica-alumina-zirconia can preferably be used as ternary mixed oxides. The mixed oxide used in the present invention includes zeolites such as USY type zeolite.

Either one or more mixed oxides selected from silica-alumina, silica-titanium oxide, silica-zirconia, silica-magnesium oxide, silica-alumina-titania, silica-alumina zirconium, tungsten-containing zirconia, sulfated zirconia, aluminum sulfate and zeolite can be used individually or in combination in the form of mixed oxides, respectively. In particular, if silica-alumina is used as the mixed oxide, the ratio (molar ratio) of silica / alumina is preferably from 1 to 20.

Although there are no specific restrictions on the zeolite, the zeolites are preferably X-type, Y-type, β-type, MOR-type or MFI-type zeolite, and among them, Y-type, β-type or MFI type. Among Y-type zeolites, zeolites such as HY-type zeolites obtained by ion exchange of an alkali metal are more preferable than alkali-metal zeolites such as Na-Y-type zeolite. USY-type zeolites (ultra-stable Y-type zeolites) obtained by dealumination of H-type zeolite can be used. USY type zeolite is obtained by acid treatment, high temperature treatment, steam treatment and the like, and its distinctive feature is high resistance to destruction of the crystal structure, the content of alkali metal ions is less than 1.0 wt.%, Preferably less than 0, 5 wt.%, The lattice constant is 2.46 nm or less, and the molar ratio silica / alumina (SiO ₂ / Al ₂ O ₃ ) is 5 or more.

Without problems in the present invention, any HY-type and USY-type zeolites can be used regardless of the preparation method, provided that the zeolite has an alumina: silica ratio in the range of 1: 2.0 to 1: 10.0 and a faujasite structure . In the present invention, crystalline aluminosilicate with a lattice constant of 2.43 to 2.46 nm, in the first case, is preferably obtained by de-alkalization of a Y-type zeolite followed by steam and / or acid treatment. If the lattice constant exceeds 2.46 nm, the crystal structure can be destroyed and the splitting activity of the catalyst and the yield of the desired fractions decreases when the aluminosilicate is forced to contact with an aqueous solution, the acidity of which is less than 3 during the above acid treatment. Aluminosilicate with a lattice constant of less than 2.43 has poor crystallinity as well as poor acidity. The catalyst has poor cleavage ability and gives the desired fractions with only a low yield. The lattice constant is calculated using the lattice pitch d, which is obtained by x-ray diffraction in accordance with the following equation:

Lattice constant = d × (h ² + k ² + l ² ) ^1/2

where h, k and l are Miller indices.

The de-alkalization is carried out by immersing a Y-type zeolite in a solution containing ammonia or the like, in order to conduct an ion exchange of an alkali metal such as Na ⁺ for ammonium ions or the like, and the resulting product is calcined. In this way, an HY-type zeolite is first prepared, and a USY (ultra-stable Y) -type zeolite with an even lower alkali metal content can be obtained by repeating several times the above sequence of treatments with intermediate preparation of a SY (stable Y) -type zeolite. The alkali metal content of the de-alkalized USY type zeolite is preferably less than 1.0% by weight and more preferably less than 0.5% by weight.

The steam treatment can be carried out by forcing the zeolite subjected to de-alkalization to come into contact with water vapor in the range from 500 to 800 ° C., and preferably in the range from 550 to 750 ° C. The acid treatment can be carried out by dipping the zeolite in an aqueous solution of nitric acid with a pH of 3 or less and the like. Either steam treatment or acid treatment can be carried out efficiently, however, crystalline aluminosilicate having the above lattice constant values can be obtained by partial de-alkalization using a combination of both steam treatment and acid treatment, followed by drying and calcination.

In addition to the Y-type zeolite, it is also possible to use the MOR-type zeolite represented by β-type zeolite and mordenite, and the MFI-type zeolite represented by ZSM-5 zeolite. Since these types of zeolites are of great importance to the ratio of silicon oxide / alumina, they can be used without special de-alkalizing treatment.

A crystalline aluminosilicate in which the silica / alumina ratio is controlled in this way can be converted into a crystalline aluminosilicate containing a transition metal, or into a crystalline aluminosilicate containing a rare earth element by dipping in a solution that contains a salt of a transition metal such as iron, cobalt, nickel, molybdenum, tungsten, copper, zinc, chromium, titanium, vanadium, zirconium, cadmium, tin or lead, or a rare metal salt such as lanthanum, cerium, ytterbium, europium or dysprosium, so that enter these metal ions. Crystalline aluminosilicate containing a transition metal crystalline aluminosilicate and a rare earth element containing crystalline aluminosilicate can be used in the hydrocracking reaction described below individually or in combination with two or more of these types of crystalline aluminosilicates.

[Binder]

As a binder, it is convenient to use porous or amorphous substances, alumina, silica-alumina, titania-alumina, zirconia-alumina, boria-alumina, etc. Of these, alumina, silica-alumina and boron-alumina are preferred, since they have high bonding strength with the mixed oxide and a large specific surface area. These inorganic oxides are not only able to serve as a carrier for the active metal, but also act as a binder, which combines with the mixed oxide and serves to enhance the strength of the catalyst. The specific surface area of the binder is preferably 30 m ² / g or more.

Fine particles of aluminum hydroxide and / or hydrated alumina (hereinafter referred to simply as “alumina powder”), in particular alumina monohydrate having a bomite structure such as pseudobomite (hereinafter, it can simply be denoted simply as “alumina”), can preferably be used as a binder, which is one of the components of the carrier, since they have the ability to increase activity and selectivity hydrocracking reaction. Fine particles of aluminum hydroxide and / or hydrated alumina containing boron oxide, in particular alumina monohydrate having a bomite structure, such as pseudobomite containing boron oxide, can also be preferably used as a binder, since they have the ability to increase the activity and selectivity of the reaction hydrocracking.

Alumina monohydrate, a commercially available source of alumina (e.g., PURAL (registered trademark), CATAPAL (registered trademark), DISPERAL (registered trademark) and DISPAL (registered trademark), which are commercially available from SASOL, VERSAL ( registered trademark), which is commercially produced by UOP, and HIQ (registered trademark), which is commercially produced by ALCOA, etc.). You can also get alumina monohydrate in the usual way by partial dehydration of alumina trihydrate. If the alumina monohydrate is in the form of a gel, then the gel can be peptized with water or acidified water. If alumina is synthesized by precipitation, the source of acidic aluminum can be selected from aluminum chloride, aluminum sulfate, aluminum nitrate, and the like, and the source of basic aluminum can be selected from sodium aluminate, potassium aluminate, and the like.

The mixed amount of the binder is preferably from 5 to 70 wt.% And preferably from 10 to 60 wt.% Of the total amount of the mixed oxide and binder of which the catalyst is composed. If the amount is less than 5 wt.%, Then the mechanical strength of the catalyst is reduced; and if it is more than 70 wt.%, the hydrocracking activity and selectivity can generally decrease. If a mixed oxide is used as USY zeolite, the amount of USY zeolite is preferably 1 to 80 wt.% Of the total amount of the mixed oxide and binder of which the catalyst is composed, and most preferably 10 to 70 wt.% . If the amount is less than 1 wt.%, The effect of increasing activity in the hydrocracking reaction when using USY zeolite is weakly expressed; and if it is more than 80 wt.%, the average selectivity of the distillate is relatively reduced.

[Metal component]

The hydrocracking catalyst of the present invention as an active component contains a metal selected from group VI and group VIII of the Periodic table. Among the metals of group VI and group VIII, mainly molybdenum, tungsten, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium and platinum are used. The metals may be used individually or a combination of two or more metals may be used. Metals are preferably added in such an amount that the total content of Group VI and Group VIII metals in the hydrocracking catalyst is preferably 0.05 to 35 wt.% And preferably 0.1 to 30 wt.%. When molybdenum is used as the metal, the molybdenum content in the hydrocracking catalyst is preferably 5 to 20% by weight, and most preferably 7 to 15% by weight. When tungsten is used as the metal, the tungsten content of the hydrocracking catalyst is preferably from 5 to 30 wt.%, And most preferably from 7 to 25 wt.%. An amount of molybdenum or tungsten less than the above is undesirable, since the hydrogenation function of the active metal, necessary for the hydrocracking reaction, is insufficient. On the other hand, if the amount of molybdenum or tungsten is greater than the ranges indicated above, the active metal exhibits an undesirable tendency to rapidly aggregate.

When molybdenum or tungsten is used as the metal, the additional addition of cobalt or nickel can lead to a beneficial enhancement of the hydrogenation function of the active metal. In this case, the total amount of cobalt or nickel in the hydrocracking catalyst is preferably from 0.5 to 10 wt.% And, most preferably, from 1 to 7 wt.%. When one or more metals selected from rhodium, iridium and platinum are used, the content of said metals is preferably from 0.1 to 5 wt.% And, most preferably, from 0.2 to 3 wt.%. If the amount is less than the above range, then effective hydrogenation cannot be achieved. If the amount is greater than the above range, the addition efficiency is undesirably degraded, which makes the process uneconomical.

The component in the form of a Group VI metal, which must be applied to the carrier as the active ingredient, can be applied by impregnating the carrier with an aqueous solution of a compound such as ammonium paramolybdate, molybdenum acid, ammonium molybdate, molybdenum phosphoric acid, ammonium tungstate, tungsten acid, tungsten anhydride and tungsten phosphoric acid.

As a component of a Group VIII metal, an aqueous solution of a compound such as nitrate, sulfate, chloride, fluoride, bromide, acetate, carbonate or phosphate of nickel or cobalt can be used; or an aqueous solution of a compound such as chloroplatinic acid, platinum dichlorotetraamine, platinum tetrachlorhexamine, platinum chloride, platinum iodonium, potassium chloroplatinate, palladium acetate, palladium chloride, palladium nitrate, palladium acetylacetonate, rhodium acetate, rhodium chloride, rhodium chloride, rhodium chloride, osmium, iridium chloride, etc.

In addition, phosphorus, boron, potassium, and rare earths such as lanthanum, cerium, ytterbium, europium, and dysprosium can be added as a third component.

[Method for producing a hydrocracking catalyst]

The hydrocracking catalyst of the present invention can be obtained by combining a mixed oxide-based support and a binder by mixing, molding the resulting mixture, then drying and calcining the resulting mixture, and then by impregnating the support with an aqueous solution of the metal component, followed by drying and calcination. A method for producing a hydrocracking catalyst of the present invention will be described below, however, the method is not limited to the following procedure. Other methods may also be used by which a catalyst having the indicated pore characteristics and performance properties can be prepared.

For the implementation of the above mixing, any mixer that is commonly used to prepare the catalyst can be used. In the General case, it is convenient to use a method that includes loading the starting compounds, adding water and mixing the mixture using a paddle mixer. The order of addition of the starting compounds, additional components, and the like is not specifically limited. Water is added during the mixing process, however, there is no need to add water if the starting compound is a suspension. In addition to water or in place of water, organic solvents such as ethanol, isopropanol, acetone, methyl ethyl ketone, methyl isobutyl ketone and the like can be added. The mixing temperature and mixing time may vary depending on the mixed oxide and binders that are used as starting compounds. There are no special restrictions on temperature and mixing time, provided that the necessary pore structure can be obtained. Similarly, other components, for example, an acid, such as nitric acid, a base, such as aqueous ammonia, an organic compound, such as citric acid and ethylene glycol, a water-soluble high molecular weight compound, such as cellulose ethers and polyvinyl alcohol, ceramic fiber, and the like, may be added and mixed in such an amount that the properties of the catalyst of the present invention are maintained.

After mixing, the mixed substances can be molded using the molding method that is commonly used in the preparation of the catalyst. In particular, it is preferable to use extrusion blow molding using a screw extruder, which allows efficiently molding the catalyst in the form of granules (cylindrical granules, granules of a special shape), grains, spherical particles, etc., as well as an oil drop method that allows efficiently form spherical particles. Although there are no special restrictions on the size of the product obtained, for example, cylindrical granules with a diameter of 0.5 to 20 mm and a length of 0.5 to 15 mm can easily be obtained.

The formed product obtained in this way is dried and calcined to obtain a carrier. Calcination can be carried out in a gas atmosphere, such as air or nitrogen, at a temperature of 300 to 900 ° C. for 0.1 to 20 hours.

The method of applying the metal component to the carrier is not particularly limited. An aqueous solution of the metal oxide or salt to be applied is obtained, such as nitrate, acetate, carbonate, phosphate or halide, and the metal component is applied by spraying, by impregnation, by ion-exchange, and the like. More than one metal component can be applied by repeating a treatment including application and drying.

For example, after the carrier is impregnated with an aqueous solution containing a component in the form of a Group VI metal, the carrier is dried at a temperature of from room temperature to 150 ° C., preferably at a temperature in the range of 100 to 130 ° C. for 0.5 hour or more, or the carrier without drying, as is, you can sequentially soak in an aqueous solution containing a component in the form of a metal of group VIII, then dry at a temperature of from room temperature to 150 ° C, preferably at a temperature in the range from 100 to 130 ° C for 0.5 hour or more followed by calc by initiating at a temperature of from 350 to 800 ° C., preferably at a temperature of from 450 to 600 ° C. for 0.5 hours, a catalyst is obtained.

The Group VI or Group VIII metal supported on the catalyst of the present invention may be in any form, such as a metal form, sulfide, and the like.

[Mechanical strength of hydrocracking catalyst and carrier]

The greater the mechanical strength of the hydrocracking catalyst, the more preferable the catalyst becomes. For example, the crushing strength of a cylindrical pellet with a diameter of 1.6 mm is preferably 3 kg or more, and more preferably 4 kg or more. In the process of preparing the catalyst by applying a metal component to the formed support by the impregnation method, it is desirable that the formed support itself be of sufficient strength so that the catalyst can be prepared in high yield. In particular, in order to ensure the mechanical strength of the molded catalyst of the present invention, the crushing strength of a cylindrical pellet with a diameter of 1.6 mm should preferably also be 3 kg or more, and more preferably 4 kg or more.

The bulk density of the catalyst is preferably from 0.4 to 2.0 g / cm ³ , more preferably from 0.5 to 1.5 g / cm ³ and, most preferably, from 0.6 to 1.2 g / cm ³ .

[Properties of hydrocracked oil]

At the hydrocracking stage, 40 vol.% Or more fractions with a boiling point of 215 ° C. or higher in the original hydrocarbon compounds are converted into fractions having a boiling point of 215 ° C. or less. The content of fractions having a boiling point of not more than 215 ° C, i.e. hydrocarbons lighter than naphthalene, in the hydrocracked oil is 40 vol% or more, preferably 50 vol% or more, more preferably 60 vol% or more, and most preferably 75 vol% or more. The content of monocyclic aromatic hydrocarbons (alkylbenzenes) in the hydrocracked oil that results from hydrocracking is preferably 30 vol% or more, more preferably 35 vol% or more, and even more preferably 40 vol% or more; the content of 1,5-cyclic aromatic hydrocarbons is preferably 30 vol.% or less, more preferably 28 vol.% or less; and the content of polycyclic aromatic hydrocarbons is preferably 10 vol% or less, more preferably 7 vol% or less, and even more preferably 5 vol% or less.

In addition, the ratio of the proportion of carbon atoms forming the aromatic cycle in the hydrocracked oil to the fraction of carbon atoms forming the aromatic cycle in the feed (ratio of the residual carbon of the aromatic cycle) is 0.5 or more, more preferably 0.6 or more and most preferably 0.7 or more. If the ratio of the residual carbon of the aromatic cycle is less than 0.5, then this means that an undesired excessive cracking reaction occurs, which leads to coking and reduces the life of the catalyst.

[Post-processing step]

In the method of the present invention, similarly to the pretreatment step, a posttreatment step may be provided, if necessary, to purify the hydrocracked oil resulting from the hydrocracking. Although there are no special restrictions on the post-treatment step, the type and amount of catalyst and the conditions used in the pre-treatment step can also be used in the post-treatment step. The post-treatment step can be carried out immediately after the hydrocracking step, in order to process the hydrocracked oil, or it can be carried out after the separation step so that each hydrocarbon fraction obtained in the separation step is processed. By implementing the post-processing step, the amount of impurities in the product can be significantly reduced. For example, sulfur and nitrogen can be reduced to 0.1 mass ppm. or less.

[Method for the separation of hydrocracked oil]

The hydrocracked oil can be divided into products such as the LPG fraction, gasoline fraction, kerosene fraction, light diesel fraction, non-aromatic ligroin fraction and monocyclic aromatic hydrocarbons using the appropriate separation step. Despite the fact that these fractions, as is, can be used as LPG, gasoline, kerosene, diesel fuel or feedstock for petrochemical synthesis, if the refined product meets the technical requirements, usually these fractions can be used to obtain these refined products by compiling mixtures and for oil refining. Special restrictions on the oil refining process are not imposed. Depending on the properties of the product, any conventional known methods may be used, such as fine distillation, adsorption separation, sorption separation, extraction separation, membrane separation and the like. Suitable operating conditions for the separation step may be selected.

Distillation is a widely used method that separates the hydrocracked oil, for example, into an LPG fraction, a gasoline fraction, a kerosene fraction and a light diesel fraction by using a difference in boiling point. In particular, an LPG fraction can be obtained from the hydrocracked oil, which is the lightest fraction with a boiling point in the range of about 0 to 30 ° C .; a gasoline fraction having a boiling point higher than the LPG fraction, which is up to about 150-215 ° C; a kerosene fraction having a boiling point higher than the gasoline fraction, which is in the range from about 215 up to 260 ° C; and a fraction of light diesel fuel having a boiling point higher than the kerosene fraction, which is in the range from about 260 up to 370 ° C. Fractions heavier than the fraction of light diesel fuel can be recycled as an unprocessed product to be processed again at the hydrocracking stage, or they can be used as starting compounds for formulating fuel compositions A and the like.

The method of extraction separation of aromatic compounds, which allows you to separate the aromatic component and the non-aromatic component using an appropriate solvent, can be applied by appropriate combination with the above distillation method. In this case, the gasoline fraction and / or the kerosene fraction obtained by distillation are mixed with a solvent, such as sulforane (tetrahydrothiophene dioxide), which selectively extracts aromatic compounds. The mixture is divided into an extract fraction in which aromatic compounds are selectively extracted with sulforane and a raffinate fraction in which paraffinic hydrocarbons that are not extracted with sulforane are concentrated by treating the mixture under extraction conditions at a temperature of from 20 to 100 ° C and pressure from normal pressure to 1 , 0 MPa. Since the extract fraction containing components with a boiling point of at least 80 ° C or higher, which is obtained by extraction treatment, contains selectively extracted aromatic compounds, if necessary, this fraction after catalytic oil refining in the presence of hydrogen can be used to obtain the product in as a source of starting aromatic substances. Since the raffinate fraction contains relatively large amounts of isoparaffins and naphthenes, this fraction, as is, can be used as a source of starting materials for formulating high-octane gasoline compositions, and can also be used as a starting material for catalytic reforming and conversion to aromatic hydrocarbons.

Aromatic components and sulforan in the extract fraction, which is extracted with sulforan, can be easily separated by distillation. The isolated sulforan can be reused as a solvent for the extraction. The isolated aromatic components can be converted to para-xylene, benzene and the like, which are of great value by transalkylation, isomerization, etc.

[Hydrocarbons obtained from processing]

As examples of hydrocarbon products obtained using the above separation methods, one can cite an LPG fraction with a boiling point in the range from minus 10 to 30 ° С, a gasoline fraction with a boiling point in the range from 30 to 215 ° С, a kerosene fraction with a boiling point in the range from 215 to 260 ° C, the fraction of light diesel fuel with a boiling point in the range from 260 to 370 ° C and the residue that remains after separation of these fractions. According to the present invention, the smaller the amount of residues, the better. The residue can be converted to lighter compounds by returning to the hydrocracking step.

You can also extract the gasoline fraction with a solvent, such as sulforane, to obtain an extract fraction and a raffinate fraction. The raffinate fraction is a non-aromatic ligroin fraction and is suitable as a source for formulating gasoline compositions, as a solvent, and the like. The extract fraction is a monocyclic aromatic hydrocarbon (alkylbenzenes), which are suitable for the production of oil products.

EXAMPLES

The method for producing the hydrocarbon fractions of the present invention is explained in detail and specifically using the examples and comparative examples that are given below.

[Preparation of hydrocracking catalyst]

1078 g of a USY type zeolite (HSZ-350HUA, manufactured by Tosoh Corp.), which has a SiO ₂ / Al ₂ O ₃ ratio of 10.5, a lattice constant of 2.439 nm, and a specific surface of 650 m ² / g, mixed with 1033 g of alumina powder (Pural SB, manufactured by SASOL Corp.) and 500 ml of a 4.0 wt.% nitric acid solution and 875 g of ion-exchange purified water were added. The mixture was stirred, extruded in the form of three-petal granules, dried at 130 ° C for six hours and calcined at 600 ° C for six hours to obtain a carrier.

The carrier was impregnated by spraying with an aqueous solution of ammonium molybdate, dried at 130 ° C for six hours, impregnated by spraying with an aqueous solution of nickel nitrate, dried at 130 ° C for six hours and calcined at 500 ° C for 30 min in a stream of air with obtaining catalyst A. The composition (supported metal content) and typical properties of catalyst A are shown in table 4.

The pore characteristics of catalyst A were measured by a nitrogen gas adsorption method and it was determined that the specific surface was 387 m ² / g, the pore volume occupied by pores with a diameter in the range from 2 to 60 nm was 0.543 ml / g, and the average pore diameter was 9, 6 nm. Catalyst A had a stable diameter of 1.2 mm, an average length of 4.0 mm, an average crushing strength of 12.0 kg, and a bulk density of 0.668 g / cm ³ . A stable diameter indicates the height of the granules if placed on a flat surface.

The following instruments were used to measure the properties of the catalyst.

[Method for determining the characteristics of pores]

To determine the characteristics of pores (specific surface area, pore volume occupied by pores with a diameter in the range from 2 to 60 nm, and average pore diameter), the ASAP 2400 device manufactured by Micromeritics was used by the method of nitrogen gas adsorption.

[Method for determining the average value of crushing strength]

The average crush strength of three-petal granules was measured using a device designed to determine the tensile strength of tablets, TH-203CP, manufactured by Toyama Sangyo Co., Ltd. A round measuring probe with a tip diameter of 5 mm was used. The measuring probe abutted and applied pressure in the center of the cylindrical sample to measure pressure at the time of destruction of the sample. The average value of crushing strength was determined by averaging the measurement results of 20 randomly selected samples.

Example 1

The light fraction (feedstock A) obtained by fractionation of light catalytic cracking oil (LCO) into two fractions at 240 ° C was used to carry out the hydrocracking reaction using catalyst A at a reaction pressure of 3.0 MPa, LHSV value of 1.0 hour ^-1 , the ratio of hydrogen / oil 1400 nl / l and a reaction temperature of 380 ° C. The properties of the feedstock A are shown in table 1, and the properties of the product are shown in table 2. In table 2, the degree of conversion of fractions with a temperature of 215 ° C or higher is the value obtained by the following equation.

The degree of conversion of fractions of 215 ° C or higher (%) = 100 fractions of 215 ° C or higher in the oil obtained after processing (% vol.) / Fraction of 215 ° C or higher in the feedstock (vol.%) × 100

The ratio of the proportion of carbon atoms forming the aromatic cycle in the hydrocracked oil to the fraction of carbon atoms forming the aromatic cycle in the feedstock (fraction of the residual carbon of the aromatic cycle) is also shown in Table 2. The yield of liquid reaction products is the residual ratio (wt.% ) after the reaction of fractions with 5 or more carbon atoms.

Example 2

The hydrocracking reaction was carried out under the same conditions as in Example 1, except that the reaction temperature was 400 ° C. The properties of the oil obtained by the reaction are shown in table 2.

Example 3

The hydrocracking reaction was carried out under the same conditions as in example 1, except that the LHSV was 0.5 hour ^-1 . The properties of the oil obtained by the reaction are shown in table 2.

Example 4

The hydrocracking reaction was carried out using feedstock C (a mixture of 30 vol.% 1-methylnaphthalene, 30 vol.% O-xylene and 40 vol.% Normal dodecane), the properties of which are shown in table 1, and catalyst A as a hydrocracking catalyst under pressure reactions 3.0 MPa, LHSV 1.0 hour ^-1 , with a hydrogen / oil ratio of 683 nl / l and at a reaction temperature of 380 ° C. The properties of the oil obtained by the reaction are shown in table 2.

Example 5

The hydrocracking reaction was carried out under the same conditions as in example 4, except that the LHSV was 0.3 h ^-1 . The properties of the oil obtained by the reaction are shown in table 2.

Comparative Example 1

The hydrocracking reaction was carried out under the same conditions as in Example 1, except that feedstock B (light catalytic cracking oil: LCO) was used, the properties of which are shown in Table 1. The properties of the oil obtained by the reaction are given in table 2.

Reference Example 2

The hydrocracking reaction was carried out under the same conditions as in Example 2, except that feedstock B (light catalytic cracking oil: LCO) was used, the properties of which are shown in Table 1. The properties of the oil obtained by the reaction are shown in table 2.

Reference Example 3

The hydrocracking reaction was carried out under the same conditions as in Example 3, except that feedstock B (light catalytic cracking oil: LCO) was used, the properties of which are shown in Table 1. The properties of the oil obtained by the reaction are given in table 2.

Reference Example 4

The hydrocracking reaction was carried out under the same conditions as in example 4, except that the reaction pressure was 1.0 MPa. The properties of the oil obtained by the reaction are shown in table 2.

Reference Example 5

The reaction was carried out using feedstock D (vacuum gas oil of Middle East crude oil: VGO), the properties of which are shown in table 1, and catalyst A at a reaction pressure of 4.0 MPa, LHSV 0.3 h ^-1 , with a hydrogen / oil ratio of 400 nl / l and at a reaction temperature of 388 ° C. The properties of the oil obtained by the reaction are shown in table 2.

The hydrocracked oils obtained in Examples 1-3 and Comparative Example 5 were separated by distillation into an LPG fraction (30 ° C. or less), a gasoline fraction (30 to 215 ° C.), a kerosene fraction (215 to 260 ° C), a fraction of light diesel fuel (from 260 to 370 ° C) and the remainder. The yield (% vol.) Of each fraction from each oil obtained as a result of the reaction is shown in table 3.

Table 1 Feedstock A Feedstock B Feedstock C Feedstock D Density g / cm ³ 0.9018 0.9136 0.8688 0.9357 Sulfur content wt. ppm 580 1380 2270 23890 Nitrogen content wt. ppm 143 260 3,5 1210 Bromine number g-Br ₂ / 100g 5 four 0,0 5,0 All aromatic hydrocarbons about.% 72,2 70.9 60.0 51.7 Monocyclic aromatic hydrocarbons about.% 15.1 10,4 30,0 7.3 1,5-cyclic aromatic hydrocarbons about.% 21.7 17.0 0 13,2 Bicyclic aromatic hydrocarbons about.% 35.5 37,4 30,0 18.1 The proportion of carbon atoms forming the aromatic cycle mol% 0 6.0 0 13.1 Tricyclic aromatic hydrocarbons or aromatic hydrocarbons with a large number of cycles ° C 52.9 52.6 45.7 31.6 Distillation Characteristics Initial Boiling Point (IBP) ° C 143 146.5 140 196 The temperature of 10% distillate ° C 200.5 206.0 145 319 The temperature of 90% of the distillate 272.5 315.50 240 533 End Point (EP) ° C 286.0 355.5 250 601 Fractions with a boiling point of 215 ° C or higher about.% 73.0 80.0 70 99

table 2 Example Comparative example one 2 3 four 5 one 2 3 four 5 Raw materials BUT BUT BUT FROM FROM AT AT AT FROM D Hydrocracking Catalyst BUT BUT BUT BUT BUT BUT A A A A Reaction temperature ° C 380 400 380 380 380 380 400 380 380 380 Reaction pressure MPa 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 1,0 4.0 Lhsv hour ^-1 1,0 1,0 0.5 1,0 0.3 1,0 1,0 0.5 1,0 0.3 Hydrogen / oil ratio nl / l 1400 1400 1400 683 683 1400 1400 1400 683 400 Reaction yield about.% 86 80 84 91 70 89 87 90 98 87 Sulfur content wt. ppm 2 2 0.8 22 7 four 6 four 32 one hundred Nitrogen content wt. ppm <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 29th Distillation Characteristics The temperature of 10% distillate ° C 78.5 88.5 85.5 30,0 <30.0 125.5 125.5 126.5 146.0 229.5 50% distillate temperature ° C 166.0 173.0 171.5 164.0 85.0 218.0 219.5 226.0 198.0 375.0 The temperature of 90% of the distillate ° C 245.0 254.5 253.0 230,0 157.0 304.0 307.5 310.0 239.0 495.0 The degree of conversion of fractions with so Kip. 215 ° C or higher % 69.9 63.0 64,4 52,2 90.3 35.0 33.8 30,0 2.2 7.5 Monocyclic aromatic hydrocarbons about.% 31,0 38.7 39.0 43.0 52.0 16.9 25.0 24.3 26.5 6.8 Benzene about.% 1,2 1,6 1,5 1.9 5.3 0.7 1,0 0.9 0.2 0 Toluene about.% 6.0 7.1 7.0 9.0 21,2 3.3 4.3 3.8 0.5 0 Xylenes about.% 8.2 8.2 8.7 23.7 20.5 4.8 5.2 4.9 24.9 0 Ortho about.% 2.1 2.0 2.1 5.9 4.7 1.4 1.3 1.3 19.5 0 Meta about.% 4.3 4.3 4.6 12.8 11.0 2,4 2.7 2.5 4.8 0 Couple about.% 1.8 1.9 2.0 5,0 4.8 1,0 1,2 1,1 0.6 0 Ethylbenzene about.% 1.8 1.7 1.8 0.5 0 0.6 1,1 1,0 0 0 1,5-cyclic aromatic hydrocarbons about.% 27.4 22.0 18.3 7.8 0,0 33.7 26.1 27.9 27.9 18.8 Bicyclic aromatic hydrocarbons about.% 8.6 6.8 4.1 0.3 0,0 16.1 13.1 10.3 9.3 13.8 Tricyclic aromatic hydrocarbons or aromatic hydrocarbons with a large number of cycles about.% 0.3 1,2 0.9 0,0 0,0 1.8 2,3 0.8 0,0 5.9 The proportion of carbon atoms forming the aromatic cycle mol% 43.6 47.1 43,4 36.9 42,2 46.1 48.5 42.9 43.6 13.7 The proportion of residual carbon of the aromatic cycle - 0.82 0.89 0.82 0.81 0.92 0.87 0.92 0.82 0.95 0.43

Table 3 Example 1 Example 2 Example 3 Reference Example 5 LPG fraction about.% 27 31 27 13 Gasoline fraction about.% 65 58 60 8 Kerosene fraction about.% fourteen 16 fifteen 10 Light diesel fraction about.% 5 6 7 32 The remainder about.% one one one 51 Total about.% 112 112 110 114

As can be seen from examples 1-3 in table 2, it was found that in comparison with the application of vacuum gas oil, widely used as a feedstock in the hydrocracking reaction (comparative example 5), when hydrocracking using hydrocarbon sources that have a suitable fraction of carbon atoms forming an aromatic cycle and a suitable boiling range, under the appropriate conditions of the hydrocracking reaction, the required monocyclic aromatic hydrocarbons can be obtained in high yield (a alkylbenzenes), in particular BTX fractions, such as the most valuable benzene and toluene. In addition, from table 3, which shows the yield of each fraction obtained from hydrocracked oils, it is also seen that with a higher yield a more valuable gasoline fraction can be obtained and at the same time an LPG fraction, a gasoline fraction, a kerosene fraction and a light diesel fuel fraction can be obtained. and reduce the content of impurities, such as sulfur and nitrogen-containing components.

Examples 6-10

1036 g of a HY type zeolite (HSZ-350HSA manufactured by Tosoh Corp.), which has a SiO ₂ / Al ₂ O ₃ ratio of 5.6, a lattice constant of 2.45 nm, and a specific surface area of 650 m ² / g, was mixed with 1390 g of alumina powder (Versal 250, manufactured by UOP Corp.) and 652 ml of a 4.0 wt.% nitric acid solution and 163 g of ion-exchange purified water were added. The mixture was stirred, extruded in the form of three-petal granules, dried at 130 ° C for six hours and calcined at 600 ° C for six hours to obtain a carrier.

The carrier was impregnated by spraying with an aqueous solution of ammonium molybdate, dried at 130 ° C for six hours, impregnated by spraying with an aqueous solution of nickel nitrate, dried at 130 ° C for six hours and calcined at 500 ° C for 30 min in an air stream with obtaining catalyst B. The properties of catalyst B are shown in table 4.

Hydrocracking of feedstock C was carried out using catalyst B instead of catalyst A, under the process conditions indicated at the top of table 5 (examples 6-10). The yield of liquid products and the properties of the resulting oil treatment are shown in table 5.

Examples 11-15

Catalyst C was prepared in the same manner as Catalyst B, except that 1202 g of NH ₄ -Y-type zeolite (HSZ-341NHA, manufactured by Tosoh Corp.), which has a SiO ₂ / Al ₂ O ₃ ratio equal to 6.9, a lattice constant of 2.452 nm, and a specific surface of 700 m ² / g and 1202 g of alumina powder (Versal 250, manufactured by UOP Corp.). The properties of catalyst C are shown in table 4.

Hydrocracking according to examples 11-15 was carried out under the same conditions as in examples 6-10, except that catalyst C was used instead of catalyst B, as indicated at the top of table 5. The yield of liquid products and the properties of the resulting oil treatment are given in table 5.

Examples 16-19

Catalyst D was prepared in the same way as Catalyst C, except that 1684 g of NH ₄ -Y type zeolite (HSZ-341NHA, manufactured by Tosoh Corp.) were used, 834 g of alumina powder (Versal 250, manufactured by UOP Corp.), 500 ml of a 4.0 wt.% Solution of nitric acid and 50 g of water purified by ion exchange. The properties of the catalyst D are shown in table 4.

Hydrocracking according to examples 16-19 was carried out under the same conditions as in examples 6-9, except that catalyst D was used instead of catalyst B, as indicated at the top of table 6. The properties of the resulting oil treatment are shown in table 6 .

Examples 20-24

Catalyst E was prepared in the same way as Catalyst B, except that 1719 g of a zeolite NH ₄ β-type (CP814E, manufactured by Zeolyst International), which has a SiO ₂ / Al ₂ O ₃ ratio of 23.6, was used and a specific surface area of 680 m ² / g, 834 g of alumina powder (Versal 250, manufactured by UOP Corp.), 500 ml of a 4.0 wt.% nitric acid solution and 100 g of ion-exchange purified water. The properties of the catalyst E are shown in table 4.

Hydrocracking according to examples 20-24 was carried out under the same conditions as in examples 6-10, except that catalyst E was used instead of catalyst B, as indicated at the top of table 6. Properties and the like of the resulting oil treatment in table 6.

Examples 25-29

Catalyst F was prepared in the same manner as catalyst B, except that 1000 g of H-β-type zeolite (HSZ-940HOA, manufactured by Tosoh Corp.), which has a SiO ₂ / Al ₂ O ₃ ratio of 36, was used. , 9, and a specific surface area of 450 m ² / g and 1390 g of alumina powder (Versal 250, manufactured by UOP Corp.). The properties of the catalyst F are shown in table 4.

Hydrocracking according to examples 25-29 was carried out under the same conditions as in examples 6-10, except that catalyst F was used instead of catalyst B, as indicated in the upper part of table 7. Properties and the like of the resulting oil treatment in table 7.

Examples 30-34

Catalyst G was obtained in the same way as catalyst F, except that 1400 g of H-β-type zeolite (HSZ-940HOA, manufactured by Tosoh Corp.) was used, 834 g of alumina powder (Versal 250, manufactured by UOP Corp.) .), 500 ml of a 4.0 wt.% Solution of nitric acid and 100 g of water purified by ion exchange. The properties of the catalyst G are shown in table 4.

Hydrocracking according to examples 30-34 was carried out under the same conditions as in examples 6-10, except that catalyst G was used instead of catalyst B, as indicated at the top of table 7. Properties and the like of the resulting oil treatment in table 7.

Examples 35-39

Catalyst H was prepared in the same manner as catalyst B, except that 1533 g of zeolite NH ₄ -ZSM-5 (CBV3020E, manufactured by Zeolyst International), which had a SiO ₂ / Al ₂ O ₃ ratio of 30.6, were used. and a specific surface area of 400 m ² / g, 834 g of alumina powder (Versal 250, manufactured by UOP Corp.), 500 ml of a 4.0 wt.% nitric acid solution and 100 g of ion-exchange purified water. The properties of the catalyst H are shown in table 4.

Hydrocracking according to examples 35-39 was carried out under the same conditions as in examples 6-10, except that catalyst H was used instead of catalyst B, as indicated in the upper part of table 8. Properties and the like of the resulting oil treatment are given in table 8.

Examples 40-44

Catalyst I was prepared in the same manner as catalyst C, except that an aqueous solution of cobalt nitrate was used instead of an aqueous solution of nickel nitrate. The properties of catalyst I are shown in table 4.

Hydrocracking according to examples 40-44 was carried out under the same conditions as in examples 6-10, except that catalyst I was used instead of catalyst B, as indicated in the upper part of table 8. Properties and the like of the resulting oil treatment in table 8.

Comparative Examples 6-10

2300 g of alumina powder (Pural SB, manufactured by SASOL Corp.) was mixed with 363 g of boric acid (manufactured by Kanto Chemical Co., Inc.) and 1000 ml of a 3.0 wt.% Nitric acid solution and 250 g of water were added, purified by ion exchange. The mixture was stirred, extruded in the form of cylindrical granules, dried at 130 ° C for six hours and calcined at 600 ° C for six hours to obtain a carrier.

The carrier was impregnated by spraying with an aqueous solution of ammonium molybdate, dried at 130 ° C for six hours, impregnated by spraying with an aqueous solution of cobalt nitrate, dried at 130 ° C for six hours and calcined at 500 ° C for 30 min in a stream of air with obtaining catalyst J. The properties of catalyst J are shown in table 4.

Hydrocracking in comparative examples 6-10 was carried out under the same conditions as in examples 6-10, except that catalyst J was used instead of catalyst A, as indicated at the top of table 9, and the reaction temperature in comparative examples 6-8 , respectively, was 320 ° C, 350 ° C and 380 ° C. The yield of liquid products and the properties of the resulting oil treatment are shown in table 9.

Table 5 Example 6 7 8 9 10 eleven 12 13 fourteen fifteen Raw materials C C C C C C C C C C Hydrocracking Catalyst B B B B B FROM C C C C Reaction temperature ° C 300 320 350 350 350 300 320 350 350 350 Reaction pressure MPa 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 Lhsv hour ^-1 1,0 1,0 1,0 1,5 0.5 1,0 1,0 1,0 1,5 0.5 Hydrogen / oil ratio nl / l 1365 1365 1365 1365 1365 1365 1365 1365 1365 1365 Reaction yield about.% 98 99 93 96 81 96 98 89 93 65 Sulfur content wt. ppm 6 four 3 2 3 2 one 0.8 0.4 3 Nitrogen content wt. ppm <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 Distillation Characteristics The temperature of 10% distillate ° C 139.0 138.0 74.0 110.0 <30.0 139.0 110.0 <30.0 85.0 <30.0 50% distillate temperature ° C 208.0 208.0 199.0 207.0 137.0 208.0 206.0 144.0 203.0 66.0 The temperature of 90% of the distillate ° C 217.0 217.0 216.0 216.0 212.0 216.0 217.0 214.0 216.0 169.0 The degree of conversion of fractions with so Kip. 215 ° C or higher % 46 41 59 65 81 65 51 76 68 one hundred Monocyclic aromatic hydrocarbons about.% 35,4 36,4 41.3 38.9 41.3 39.8 40.3 40.6 40,4 36,4 Benzene about.% 0.3 0.5 1.3 0.8 2.6 0.4 0.8 2.0 1.3 3.2 Toluene about.% 1,6 2.6 6.3 3.8 12.6 2.6 4.0 9.1 5.9 13.6 Xylenes about.% 27.7 25.7 25,4 27.9 18.1 27.1 26.5 21.5 26.3 14,4 Ortho about.% 15.0 11.6 8.3 13.6 4.1 12.5 10.6 6.1 12.1 3.2 Meta about.% 10.9 11.6 13.0 11.6 9.9 12,2 12.7 11,4 11.3 7.8 Couple about.% 1.8 2.5 4.1 2.7 4.1 2,4 3.2 4.0 2.9 3.4 Ethylbenzene about.% 0 0.1 0.3 0.1 0.5 0.1 0.1 0.4 0.3 0 1,5-cyclic aromatic hydrocarbons about.% 13,2 16,2 11,4 15.8 5,4 14.0 12.3 8.2 12.7 0 Bicyclic aromatic hydrocarbons about.% 0.3 0.3 0.2 0.6 0 0.2 1,0 0.6 0.4 0 Tricyclic aromatic hydrocarbons or aromatic hydrocarbons with a large number of cycles about.% 0 0 0 0 0 0 0 0 0 0 The proportion of carbon atoms forming the aromatic cycle mol% 30.5 34.0 34.5 36.0 35.6 34.7 33,2 34.2 34,4 36.6 The proportion of residual carbon of the aromatic cycle - 0.67 0.74 0.76 0.79 0.78 0.76 0.73 0.75 0.75 0.80

Table 6 Example 16 17 eighteen 19 twenty 21 22 23 24 Raw materials C C C C C C C C C Hydrocracking Catalyst D D D D E E E E E Reaction temperature ° C 300 320 350 350 300 320 350 350 350 Reaction pressure MPa 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 Lhsv hour ^-1 1,0 1,0 1,0 1,5 1,0 1,0 1,0 1,5 0.5 Hydrogen / oil ratio nl / l 1365 1365 1365 1365 1365 1365 1365 1365 1365 Reaction yield about.% 90 91 83 91 97 77 69 75 65 Sulfur content wt. ppm 3 2 2 0.8 3 3 6 7 2 Nitrogen content wt. ppm <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 Distillation Characteristics The temperature of 10% distillate ° C 139.0 110.0 <30.0 34.0 59.0 <30.0 <30.0 <30.0 <30.0 50% distillate temperature ° C 207.0 203.0 130.0 189.0 144.0 81.0 105.0 90.0 104.0 The temperature of 90% of the distillate ° C 217.0 216.0 214.0 216.0 220.0 143.0 166.0 164.0 165.0 The degree of conversion of fractions with so Kip. 215 ° C or higher % 40 59 81 65 51 97 one hundred 92 one hundred Monocyclic aromatic hydrocarbons about.% 38.1 41.9 40.3 41.9 39.7 50.1 68.5 50,2 69.6 Benzene about.% 0.5 1,2 2.7 1.7 0.7 2.9 3.2 2,3 4.0 Toluene about.% 2.9 5,6 12.7 7.9 1.8 10.9 17.1 9.2 21.0 Xylenes about.% 25,2 25.6 17.3 24.0 31,0 27.0 26.7 30.6 27.6 Ortho about.% 10.6 8.1 3.9 8.4 13.0 6.1 6.1 7.5 6.2 Meta about.% 12.1 13.6 9.5 12.0 14,4 14.7 14.3 16,2 14.9 Couple about.% 2.5 3.9 3.9 3.6 3.6 6.2 6.3 6.9 6.5 Ethylbenzene about.% 0.1 0.2 0.6 0.4 0.2 1.4 1,6 1,2 1,2 1,5-cyclic aromatic hydrocarbons about.% 13.6 7.3 2,8 7.7 22.5 2.2 0 4.7 0 Bicyclic aromatic hydrocarbons about.% 0.2 0 0 0.2 0.4 0 0 0.5 0 Tricyclic aromatic hydrocarbons or aromatic hydrocarbons with a large number of cycles about.% 0 0 0 0 0 0 0 0 0 The proportion of carbon atoms forming the aromatic cycle mol% 32.1 31.3 32.9 33.3 43.8 53.3 65,4 55,4 64.1 The proportion of residual carbon of the aromatic cycle - 0.70 0.68 0.72 0.73 0.96 1.17 1.43 1.21 1.40

Table 7 Example 25 26 27 28 29th thirty 31 32 33 34 Raw materials C C C C C C C C C C Hydrocracking Catalyst F F F F F G G G G G Reaction temperature ° C 300 320 350 350 350 300 320 350 350 350 Reaction pressure MPa 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 Lhsv hour ^-1 1,0 1,0 1,0 1,5 0.5 1,0 1,0 1,0 1,5 0.5 Hydrogen / oil ratio nl / l 1365 1365 1365 1365 1365 1365 1365 1365 1365 1365 Reaction yield about.% 94 86 77 73 63 99 82 76 74 74 Sulfur content wt. ppm 2 2 0.6 0.5 3 2 2 3 2 one Nitrogen content wt. ppm <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 Distillation Characteristics The temperature of 10% distillate ° C 83.0 <30.0 <30.0 <30.0 <30.0 109.0 <30.0 <30.0 <30.0 <30.0 50% distillate temperature ° C 197.0 115.0 119.0 85.0 104.0 203.0 109.0 128.0 86.0 119.0 The temperature of 90% of the distillate ° C 215.0 202.0 165.0 150.0 166.0 216.0 173.0 168.0 161.0 169.0 The degree of conversion of fractions with so Kip. 215 ° C or higher % 73 89 one hundred 97 one hundred 68 92 one hundred 95 one hundred Monocyclic aromatic hydrocarbons about.% 40.9 46.5 69.9 50.1 66.7 38.5 48.8 75.9 49.2 73,4 Benzene about.% 0.7 1,6 2,3 2,3 2.7 0.5 2.1 2.6 2.2 2.7 Toluene about.% 1,5 6.4 15.1 10.6 16,4 1,1 8.6 16.7 9.5 16.9 Xylenes about.% 30,2 28.1 28.8 26.8 26.5 31,2 27.4 30,0 28.0 28,4 Ortho about.% 12.5 7.4 6.7 6.4 6.1 14.0 6.5 6.9 7.0 6.5 Meta about.% 14.2 15,5 15.4 14.5 14.2 13.9 15,2 15.9 14.9 15,2 Couple about.% 3,5 5.2 6.7 5.9 6.2 3.3 5.7 7.2 6.1 6.7 Ethylbenzene about.% 0.2 0.9 1.7 1.4 1.3 0.2 1.3 1.9 1.3 1.7 1,5-cyclic aromatic hydrocarbons about.% 19,2 10.7 0 2.2 0 18.5 6.1 0 3.2 0 Bicyclic aromatic hydrocarbons about.% 0.1 0.1 0 0 0 0.4 0.1 0 0.2 0 Tricyclic aromatic hydrocarbons or aromatic hydrocarbons with a large number of cycles about.% 0 0 0 0 0 0 0 0 0 0 The proportion of carbon atoms forming the aromatic cycle mol% 41.2 50.7 64.3 53.5 63.6 37.5 51.6 66.8 53.5 66.0 The proportion of residual carbon of the aromatic cycle - 0.90 1,11 1.41 1.17 1.39 0.82 1.13 1.46 1.17 1.44

Table 8 Example 35 36 37 38 39 40 41 42 43 44 Raw materials C C C C C C C C C C Hydrocracking Catalyst H H H H H I I I I I Reaction temperature ° C 300 320 350 350 350 300 320 350 350 350 Reaction pressure MPa 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 Lhsv hour ^-1 1,0 1,0 1,0 1,5 0.5 1,0 1,0 1,0 1,5 0.5 Hydrogen / oil ratio nl / l 1365 1365 1365 1365 1365 1365 1365 1365 1365 1365 Reaction yield about.% 70 31 41 32 39 one hundred one hundred 96 98 80 Sulfur content wt. ppm four 61 fourteen 3 one 3 one 2 3 2 Nitrogen content wt. ppm <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 Distillation Characteristics The temperature of 10% distillate ° C <30.0 <30.0 <30.0 <30.0 <30.0 139.0 137.0 59.0 109.0 <30.0 50% distillate temperature ° C 138.0 <30.0 84.0 <30.0 38,0 208.0 207.0 198.0 206.0 137.0 The temperature of 90% of the distillate ° C 220.0 103.0 139.0 105.0 110.0 220.0 220.0 216.0 216.0 212.0 The degree of conversion of fractions with so Kip. 215 ° C or higher % 65 one hundred one hundred one hundred one hundred 40 41 59 65 81 Monocyclic aromatic hydrocarbons about.% 61.1 31.7 70.6 39.9 60.7 37.1 39.3 42.1 38.8 39.9 Benzene about.% 2,4 5.3 9.3 8.7 13.1 0.3 0.6 1,5 0.9 2.6 Toluene about.% 11.6 17.5 29.2 23.6 35.3 1.8 3.2 7.1 4.3 12.3 Xylenes about.% 35.6 8.8 26.2 7.6 12,4 27,2 27.0 25,2 27.3 17,2 Ortho about.% 7.5 0 5,6 0 0 15.1 11.8 8.2 13,4 4.0 Meta about.% 20.3 8.8 14.2 7.6 12,4 10.5 12.5 13.0 11.3 9.3 Couple about.% 7.8 0 6.4 0 0 1,6 2.7 4.0 2.6 3.9 Ethylbenzene about.% 1,5 0 0 0 0 0 0.3 0.3 0.2 0.5 1,5-cyclic aromatic hydrocarbons about.% 17,2 0 0 0 0 17.6 14.6 9.9 15.3 4.8 Bicyclic aromatic hydrocarbons about.% 0.2 0 0 0 0 0.3 0.3 0.2 0.7 0 Tricyclic aromatic hydrocarbons or aromatic hydrocarbons with a large number of cycles about.% 0 0 0 0 0 0 0 0 0 0 The proportion of carbon atoms forming the aromatic cycle mol% 57.3 63.0 77.0 69.0 75.3 35,2 33.5 34.8 35.7 34.3 The proportion of residual carbon of the aromatic cycle - 1.25 1.38 1.68 1.51 1.65 0.77 0.73 0.76 0.78 0.75

Table 9 Comparative example 6 7 8 9 10 Raw materials C C C C C Hydrocracking Catalyst J J J J J Reaction temperature ° C 320 350 380 350 350 Reaction pressure MPa 3.0 3.0 3.0 3.0 3.0 Lhsv hour ^-1 1,0 1,0 1,0 1,5 0.5 Hydrogen / oil ratio nl / l 1365 1365 1365 1365 1365 Reaction yield about.% 83 84 83 90 70 Sulfur content wt. ppm 8 7 6 3 fifteen Nitrogen content wt. ppm <0.5 <0.5 <0.5 <0.5 <0.5 Distillation Characteristics The temperature of 10% distillate ° C 141.0 141.0 141.0 141.0 143.0 50% distillate temperature ° C 210.0 211.0 209.0 212.0 209.0 The temperature of 90% of the distillate ° C 228.0 232.0 233.0 238.0 224.0 The degree of conversion of fractions with so Kip. 215 ° C or higher % 27 27 32 3 46 Monocyclic aromatic hydrocarbons about.% 28.9 29.9 30.6 25.6 33,2 Benzene about.% 0 0 0.1 0 0.1 Toluene about.% 0 0.1 0.2 0 0.1 Xylenes about.% 26.1 26,4 26.6 23.9 28.7 Ortho about.% 25.8 26.1 25.7 23.7 28.0 Meta about.% 0.3 0.3 0.8 0.2 0.6 Couple about.% 0 0 0.1 0 0.1 Ethylbenzene about.% 0 0 0 0 0 1,5-cyclic aromatic hydrocarbons about.% 24.7 23.0 24.0 29.0 20.1 Bicyclic aromatic hydrocarbons about.% 1,6 3,7 5.2 8.4 2,4 Tricyclic aromatic hydrocarbons or aromatic hydrocarbons with a large number of cycles about.% 0 0 0 0 0 The proportion of carbon atoms forming the aromatic cycle mol% 30.7 32.9 38.3 37.9 34.6 The proportion of residual carbon of the aromatic cycle - 0.67 0.72 0.84 0.83 0.76

Examples 45-47

The hydrocracking reaction was carried out under the same conditions as in example 4, except that the LHSV was 0.5 h ⁻¹ , the hydrogen / oil ratio was 1365 nl / l, the reaction temperature was 320 ° C., and the reaction pressure in the example 45 was 5.0 MPa, the reaction pressure in example 46 was 7.0 MPa, the reaction pressure in example 47 was 9.0 MPa. The properties of the oil obtained by the reaction are shown in table 10.

Table 10 Example 45 46 47 Raw materials C C C Hydrocracking Catalyst A A A Reaction temperature ° C 320 320 320 Reaction pressure MPa 5,0 7.0 9.0 Lhsv hour ^-1 0.5 0.5 0.5 Hydrogen / oil ratio nl / l 1365 1365 1365 Reaction yield about.% 85 84 85 Sulfur content wt. ppm 13 7 four Nitrogen content wt. ppm <0.5 <0.5 <0.5 Distillation Characteristics The temperature of 10% distillate ° C 121.0 110.5 110.5 50% distillate temperature ° C 207.0 203.0 203.0 The temperature of 90% of the distillate ° C 215.0 214.5 215.0 The degree of conversion of fractions with so Kip. 215 ° C or higher % 84 89 86 Monocyclic aromatic hydrocarbons about.% 32,5 35,4 34.5 Benzene about.% 0.8 1,2 1,1 Toluene about.% 3.2 4.9 4,5 Xylenes about.% 18.5 18.7 18.2 Ortho about.% 7.2 5.7 5,6 Meta about.% 9.3 10,2 9.9 Couple about.% 2.0 2,8 2.7 Ethylbenzene about.% % vol. 0.2 0.2 1,5-cyclic aromatic hydrocarbons about.% 6.8 % vol. 5,4 Bicyclic aromatic hydrocarbons about.% 0 % vol. 0 Tricyclic aromatic hydrocarbons or aromatic hydrocarbons with a large number of cycles about.% 0 0 0 The proportion of carbon atoms forming the aromatic cycle mol% 28.6 30.9 30,0 The proportion of residual carbon of the aromatic cycle - 0.63 0.68 0.66

As can be clearly seen from examples 6-47 in tables 5-8 and 10, it was found that, compared with the application of a conventional hydrocracking catalyst widely used for carrying out a hydrocracking reaction (comparative examples 6-10), when hydrocracking specific hydrocarbon sources using a suitable of the hydrocracking catalyst, the conversion of bicyclic aromatic hydrocarbons into the required monocyclic aromatic hydrocarbons (alkylbenzenes) is efficiently carried out and the most valuable BTX fractions, such as benzene and toluene. It has also been shown that hydrocracking is effective in reducing the content of impurities, such as sulfur and nitrogen components.

The properties of the starting compounds and oils obtained by the reaction in the above examples and comparative examples were analyzed using the following methods.

Density was measured by varying density in accordance with JIS K2249, and distillation parameters were determined by atmospheric pressure distillation in accordance with JIS K2254.

The fraction of carbon atoms forming an aromatic ring was determined using a nuclear magnetic resonance spectrometer (NMR) (GSX270, manufactured by JEOL Ltd.) using deuterochloroform as a solvent and tetramethylsilane (0 ppm) as an internal standard. The carbon atoms forming the aromatic cycle and the carbon atoms forming the aliphatic structure for each carbon-containing group were quantitatively determined by the calculation method from the ratio when integrating the spectrum signals with the Fourier transform based on measurements carried out in the SGNNE mode at 32768 points with the width of the frequency domain of observation 27027 Hz, a pulse width of 2 μs, a pulse delay time of 30 s and a pulse count of 2000. Carbon atoms with a chemical shift of 120 to 150 ppm. in the resulting spectrum were considered to belong to aromatic carbon atoms and are indicated in mol.% of the total number of carbon atoms.

The composition of monocyclic aromatic hydrocarbons (alkylbenzenes) (gasoline, toluene and xylene) and the composition of 1,5-cyclic aromatic hydrocarbons (tetralins) were determined using a carbon composition analyzer (manufactured by Shimadzu Corp.) and calculated in accordance with JIS K2536.

The type analysis (cycle analysis) of aromatic compounds was carried out in accordance with the methodology of the Japan Petrochemical Institute (JPI-5S-49-97) using high-performance liquid chromatography (HPLC), while the n-hexane and RI method were used as the mobile phase as a detector .

Sulfur content was determined in accordance with JIS K2541 Method for Determining Sulfur Content, where an X-ray fluorescence method was used for a sample with a high sulfur content, and coulometric microtiter was used for a sample with a low sulfur content. The nitrogen content was determined by chemiluminescence in accordance with the method of JIS K2609 Determination of nitrogen content.

The bromine number was determined by electrometric titration in accordance with JIS K2605 Determination of the bromine number.

Industrial applicability

As indicated above, according to the present invention, polycyclic aromatic hydrocarbons that were used only as fuel, such as heavy oil or light diesel fuel, can be effectively and selectively converted to monocyclic aromatic hydrocarbons, which are more valuable alkylbenzenes, by hydrocracking specific starting materials. compounds in the specific conditions of the process, without causing problems such as coking. Thus, fractions that were not used as starting compounds for monocyclic aromatic hydrocarbons can be used, and thus it is more efficient to use sources of petrochemical feedstocks.

Claims (8)

1. A method of producing hydrocarbon fractions, comprising the step of catalytic hydrocracking of starting hydrocarbon compounds that contain polycyclic aromatic hydrocarbons and in which the ratio of carbon atoms forming the aromatic cycle is not less than 35 mol%, wherein said ratio is the fraction of carbon atoms, forming aromatic cycles in the total number of carbon atoms in oil in the presence of hydrogen in order to convert at least 40% of the fractions whose boiling point is It is not less than 215 ° C in the fraction whose boiling point is less than 215 ° C, and to obtain hydrocracked petroleum oil containing 30 vol.% or more monocyclic aromatic hydrocarbons. 2. The method of claim 1 wherein the operating conditions in the hydrocracking step are a pressure which ranges from 2 to 10 MPa, a temperature which is from 200 to 450 ° C, LHSV, which is 0.1 to 10.0 parts ^{- 1} , the hydrogen / oil ratio, which is from 100 to 5000 nl / l, and the fraction of residual carbon of the aromatic cycle, which is the ratio of the fraction of carbon atoms forming the aromatic cycle, in the hydrocracked oil to the fraction of carbon atoms forming the aromatic cycle in the original hydrocarbon compounds is not m her than 0.5. 3. The method according to claim 1 or 2, where the starting hydrocarbon compounds are petroleum oil fractions obtained from a catalytic cracking unit, thermal cracking unit, ethylene cracking unit, supercritical liquid cracking unit or thermal reforming unit, or a mixture of two or more the amount of these fractions of petroleum oil. 4. The method according to claim 1, where the distillation characteristics of the starting hydrocarbon compounds are such that 10 vol.% Of the distillate has a boiling point in the range from 140 to 230 °, and 90 vol.% Of the distillate has a boiling point in the range from 230 to 600 °. 5. The method according to claim 1, which further includes a separation step in order to obtain at least two hydrocarbon fractions selected from an LPG fraction, a gasoline fraction, a kerosene fraction, a light diesel fraction, a non-aromatic naphtha fraction and a monocyclic aromatic hydrocarbon fraction, from hydrocracked oil, which is obtained by hydrocracking. 6. The method according to claim 1, where the hydrocracking catalyst includes a carrier, which is a mixed oxide, and a binder that combines a mixed oxide and at least one metal selected from metals of group VI and metals of group VIII of the Periodic table of elements and deposited on the carrier, and has the following properties: specific surface area from 100 to 800 m ² / g, average pore diameter from 3 to 15 nm, and the pore volume occupied by pores with a diameter from 2 to 60 nm, is from 0.1 to 1, 0 ml / g. 7. The method according to claim 6, where the mixed oxide includes at least one of mixed oxides of silicon and aluminum, mixed oxides of silicon and titanium, mixed oxides of silicon and zirconium, mixed oxides of silicon and magnesium, mixed oxides of silicon, aluminum and titanium mixed oxides of silicon, aluminum and zirconium, tungsten-containing zirconium oxide, sulfated zirconium oxide and zeolite. 8. The method according to claim 6, where the binder includes at least one of alumina, mixed silicon oxide and aluminum and a mixed oxide of boron and aluminum.