Hydrocracking catalyst comprising a specific zeolite y for naphtha production

Abstract

The invention relates to a hydrocracking catalyst comprising at least one hydro-dehydrogenating element selected from the group consisting of group VIB elements and non-noble group VIII elements, individually or as a mixture, from the periodic table, and a support comprising at least one porous mineral matrix, a first zeolite Y having an initial crystal parameter a0 of the elementary mesh that is between 24.40 Å and 24.52 Å, a BET specific surface area of between 850 and 1020 m2 / g, a microporous volume determined by nitrogen adsorption of greater than 0.28 ml / g and a Brønsted acidity of greater than 600 micromoles / g.

Description

[0001] HYDROCRACKING CATALYST COMPRISING A SPECIFIC Y-ZEOLITE FOR THE PRODUCTION OF NAPHTHA

[0002] Field of invention

[0003] The invention relates to a USY zeolite-based hydrocracking catalyst and its use for the production of naphtha by hydrocracking vacuum distillate and diesel-type petroleum fractions. This type of process is particularly used in schemes intended for the conversion of hydrocarbon feedstocks for the production of petrochemical intermediates and gasoline fuels.

[0004] Hydrocracking catalysts are generally classified on the basis of the nature of their acid function, in particular catalysts comprising an amorphous acid function of the silica-alumina type and catalysts comprising a zeolitic cracking function such as zeolite Y or zeolite beta.

[0005] Hydrocracking catalysts are also classified according to the major product obtained when used in a hydrocracking process, the two major products being middle distillates and naphtha.

[0006] Naphtha cut is the petroleum fraction with a lower boiling point than the middle distillate cut. The middle distillate cut generally has a cut point between 150°C and 370°C to maximize kerosene and diesel production. However, in the case of a process specifically oriented to the production of naphtha, for example, the lower cut point of the middle distillate cut can be increased to increase naphtha yields.

[0007] For this purpose, the naphtha cut can have boiling points ranging from that of hydrocarbon compounds having 6 carbon atoms per molecule (or 68°C boiling point) up to 216°C and includes the gasoline cut.

[0008] There is a strong demand for gasoline and naphtha cuts. This is why refiners have focused for several years on naphtha-selective hydrocracking catalysts. It is known to use FAU-type zeolite catalysts to produce a naphtha cut.

[0009] US7611689 (Shell) describes a FAU type Y zeolite, a catalyst comprising said zeolite, its preparation and its use in a hydrocracking process. In particular, the FAU zeolite has a lattice parameter of between 24.40 and 24.50 angstroms (Å), a silica to alumina molar ratio (SAR) of between 5 and 10, a BET specific surface area of ​​between 650 and 900 m2 / g and an alkali metal content of less than 0.15% by weight. It is demonstrated that such zeolites have a high selectivity towards the naphtha fraction and in particular a high selectivity towards the heavy naphtha fraction, when used in a hydrocracking process.

[0010] Patent application WO11067258 (Shell) describes the preparation of a FAU zeolite having a lattice parameter between 24.42 and 24.52 angstroms (Â), a silica to alumina molar ratio (SAR) between 10 and 15, and a BET specific surface area between 910 and 1020 m2 / g. The family teaches that the catalyst comprising this zeolite is particularly selective towards the naphtha fraction when used in a hydrocarbon fraction conversion process.

[0011] Patent application WO040487988 (Shell) describes a hydrocracking process using a catalyst comprising a Y zeolite having a low lattice parameter of between 24.10 and 24.40 angstroms (Å), a silica to alumina molar ratio (SAR) greater than 12 and preferably between 20 and 100 and a BET specific surface area greater than 850 m2 / g and a micropore volume greater than 0.28 ml / g. WO040487988 teaches that zeolites having a low lattice parameter are known to be selective towards the middle distillate cut but less active than zeolites having a higher lattice parameter. Catalysts comprising the low lattice parameter zeolites according to the invention of WO040487988 nevertheless make it possible to obtain high activity combined with good selectivity towards middle distillates.

[0012] Other Y and Beta zeolite catalysts can also be used.

[0013] US7510645 (UOP) describes a hydrocracking catalyst containing a Beta zeolite and a Y zeolite, the Y zeolite having a lattice parameter between 24.38 and 24.50 angstroms (Å), the catalyst being characterized by a Y / Beta mass ratio between 5 and 12. The catalyst has a relatively high proportion of Y zeolite compared to the proportion of Beta zeolite. It is demonstrated that these catalysts have improved selectivity and activity compared to conventional commercial catalysts. Also described is a hydrocracking process using said catalysts at high temperature and high pressure to convert a hydrocarbon feedstock into a product having a lower boiling point and molecular weight. In particular, the product obtained comprises a large proportion of a component boiling in the temperature range of the naphtha cut (C6-216°C).

[0014] In attempting to develop a new selective hydrocracking catalyst for the naphtha fraction, the applicant surprisingly discovered that a catalyst comprising at least one hydro-dehydrogenating element chosen from the group formed by the non-noble elements of group VIB and group VIII of the periodic table, and a support comprising at least one porous mineral matrix, a Y zeolite having an initial crystalline parameter aO of the elementary mesh greater than or equal to 24.40 Å, a BET specific surface area of ​​between 850 and 1020 m2 / g, a micropore volume determined by nitrogen adsorption greater than 0.28 ml / g and a Bronsted acidity greater than 600 micromole / g makes it possible to obtain improved selectivity towards the naphtha fraction, in particular compared to the catalysts of the state of the art.

[0015] Subject of the invention

[0016] More specifically, the present invention relates to a selective hydrocracking catalyst for the naphtha fraction, comprising at least one hydro-dehydrogenating element chosen from the group formed by the elements of group VIB and of group VIII non-noble taken alone or in a mixture of the periodic table, and a support comprising at least one porous mineral matrix, a Y zeolite having an initial crystalline parameter aO of the elementary mesh of between 24.40 Å and 24.52 Å, a BET specific surface area of ​​between 850 and 1020 m2 / g, a micropore volume determined by nitrogen adsorption greater than 0.28 ml / g and a Bronsted acidity greater than 600 micromole / g.

[0017] Another object of the present invention is a process for hydrocracking a hydrocarbon feedstock in the presence of said catalyst.

[0018] An advantage of the present invention is to provide a hydrocracking catalyst allowing the obtaining of an improved selectivity towards the naphtha cut when said catalyst is used in a hydrocracking process according to the invention, compared to the catalysts of the state of the art.

[0019] In the present invention, the selectivity of hydrocracking catalysts for the production of naphtha is determined during a catalytic test and corresponds to the fraction, in weight percentage, of the boiling product in the range of the naphtha cut, i.e. between the boiling temperature of hydrocarbon compounds having 6 carbon atoms per molecule (or 68°C boiling point) up to 216°C, relative to the total mass of product at the outlet of the process.

[0020] According to an advantageous embodiment, the catalyst according to the invention also comprises a beta zeolite.

[0021] An advantage of the advantageous embodiment of the present invention is to provide a hydrocracking catalyst comprising said Y zeolite having the specific characteristics claimed and a beta zeolite in a specific Y / beta mass ratio allowing not only the obtaining of an improved selectivity towards the naphtha cut when said catalyst is used in a hydrocracking process according to the invention, but also an improved activity compared to the catalysts of the prior art.

[0022] In the present invention, the converting activity of hydrocracking catalysts for the production of naphtha is determined during a catalytic test by comparing the temperature at which the catalyst must be operated to produce at least 65% by weight of products having a boiling point below 216°C. The lower the required temperature, the more active the catalyst. This reduction in temperature makes it possible, for example, to limit the energy consumption of the process and to increase the catalyst usage cycle time, or even to treat less reactive feedstocks without modifying the capacity and the process flowsheet.

[0023] Throughout the rest of the text, the term specific surface area refers to the BET specific surface area (SBET) determined by nitrogen adsorption in accordance with ASTM 4365-19 established from the BRUNAUER-EMMETT-TELLER method described in the periodical "The Journal of American Society", 60, 309, (1938). Analysis of the texture by nitrogen adsorption also makes it possible to determine the micropore volume, i.e. the volume of pores with an opening of less than 2 nm. Before analysis, the zeolite powder is activated at 500°C for 5 hours. In the same way, the volume of mesopores is determined by nitrogen adsorption. Throughout the rest of the text, the term "micropores" refers to pores with an opening of less than 2 nm, and the term "mesopores" refers to pores with an opening of more than 2 nm.

[0024] Throughout the rest of the text, the Bronsted acidity of zeolite Y is measured by adsorption and subsequent thermodesorption of pyridine followed by infrared spectroscopy (FTIR). This method is conventionally used to characterize acidic solids such as zeolite Y as described in the periodical CA Emeis "Journal of Catalysis", 141, 347, (1993). Before analysis, the zeolite powder is compacted in the form of a 16 mm diameter pellet and is activated under secondary vacuum at 450°C. The introduction of pyridine in the gas phase in contact with the activated pellet as well as the thermodesorption step are carried out at 150°C. The concentration of pyridinium ion detected by FTIR after thermodesorption at 150°C corresponds to the Bronsted acidity of the zeolite and is expressed in micromole / g.

[0025] For the purposes of the present invention, the various embodiments presented can be used alone or in combination with each other, without limitation of combination.

[0026] For the purposes of the present invention, the different parameter ranges for a given step such as pressure ranges and temperature ranges may be used alone or in combination. For example, for the purposes of the present invention, a preferred range of pressure values ​​may be combined with a more preferred range of temperature values.

[0027] In the following text, the groups of chemical elements are given according to the CAS classification (CRC Handbook of Chemistry and Physics, publisher CRC press, editor-in-chief DR Lide, 81st edition, 2000-2001). For example, group VIII according to the CAS classification corresponds to the metals in columns 8, 9 and 10 according to the new IUPAC classification, and group VIB to the metals in column 6.

[0028] In the remainder of the text, the expressions "between ... and ..." and "between .... and ..." are equivalent and mean that the limit values ​​of the interval are included in the range of values ​​described. If this were not the case and the limit values ​​were not included in the range described, such clarification will be provided by the present invention. In the present description, the expression "greater than ..." is understood as strictly greater, and symbolized by the sign ">", and the expression "less than" as strictly less, and symbolized by the sign "<".

[0029] In this description, the overall SiO2 / AI2O3 molar ratio of a zeolite is also called SAR or silica-alumina ratio according to English terminology. The SiO2 / AI2O3 molar ratio is measured by X-ray fluorescence.

[0030] Detailed description of the invention

[0031] The hydro / dehydrogenating function

[0032] According to the invention, the catalyst comprises at least one hydro-dehydrogenating element chosen from the group formed by the non-noble elements of group VIB and group VIII of the periodic table, taken alone or as a mixture.

[0033] Preferably, the elements of group VIII are chosen from iron, cobalt, nickel, taken alone or in a mixture, and preferably from nickel and cobalt. Preferably, the elements of group VIB are chosen from tungsten and molybdenum, taken alone or in a mixture. The following combinations of metals are preferred: nickel-molybdenum, cobalt-molybdenum, nickel-tungsten, cobalt-tungsten, and very preferably: nickel-molybdenum, nickel-tungsten. It is also possible to use combinations of three metals such as for example nickel-cobalt-molybdenum.

[0034] The content of the catalyst in group VIII element is advantageously between 0.5 and 8% by weight of oxide relative to the total weight of said catalyst, preferably between 0.5 and 6% by weight of oxide and very preferably between 1.0 and 4% by weight of oxide. The content of the catalyst in group VIB element is advantageously between 1 and 30% by weight of oxide relative to the total weight of said catalyst, preferably between 2 and 25% by weight of oxide, very preferably between 5 and 20% by weight of oxide, and even more preferably between 5 and 16% by weight of oxide.

[0035] Preferably, the catalyst used according to the invention may also contain a promoter element chosen from phosphorus, boron, silicon, very preferably phosphorus. When the catalyst contains phosphorus, the phosphorus content is advantageously between 0.5 and 10% by weight of P2O5 oxide relative to the total weight of said catalyst, preferably between 1 and 6% by weight of P2O5 oxide and more preferably between 1 and 4% by weight of P2O5 oxide.

[0036] The support

[0037] The catalyst according to the invention comprises a support which comprises and is preferably constituted by at least one porous mineral matrix, a Y zeolite, preferably a USY dealuminated zeolite, said Y zeolite having an initial crystalline parameter aO of the elementary mesh of between 24.40 Å and 24.52 Å, a BET specific surface of between 850 and 1020 m2 / g, a micropore volume greater than 0.28 ml / g and a Bronsted acidity greater than 600 micromole / g.

[0038] The porous mineral matrix used in the catalyst support, also called binder, is advantageously composed of at least one refractory oxide, preferably chosen from the group formed by alumina, silica-alumina, clay, titanium oxide, boron oxide and zirconia, taken alone or as a mixture. Preferably, the porous mineral matrix is ​​chosen from alumina and silica-alumina, taken alone or as a mixture. More preferably, the porous mineral matrix is ​​alumina. Alumina can advantageously be in any of its forms known to those skilled in the art. Very preferably, the alumina is gamma alumina, for example boehmite.

[0039] Preferably, said support comprises from 15 to 55% by weight of binder, preferably from 25% to 50% by weight, and very preferably between 25% and 40% by weight, relative to the total weight of said support.

[0040] According to the invention, the support comprises a Y zeolite having an initial crystalline parameter aO of the elementary mesh of between 24.40 Å and 24.52 Å.

[0041] Preferably, the initial crystalline parameter aO of the elementary mesh of the zeolite Y used is between 24.40 and 24.51 Å, preferably between 24.43 and 24.51 Å and very preferably between 24.45 and 24.48 Å.

[0042] The initial crystal parameter aO of the unit cell of zeolite Y given is the value of the initial crystal parameter aO of zeolite Y used in the synthesis of the catalyst according to the invention. The initial crystal parameter aO of the unit cell of zeolite Y is measured by X-ray diffraction according to the ASTM 03942-80 standard.

[0043] According to the invention, said Y zeolite has a specific surface area measured by nitrogen physisorption according to the BET method of between 850 and 1020 m2 / g, preferably between 875 and 995 m2 / g, and preferably between 900 and 970 m2 / g.

[0044] According to the invention, said zeolite Y has a microporous volume determined by nitrogen adsorption greater than 0.28 ml / g and preferably greater than 0.30 ml / g and advantageously greater than 0.31 ml / g and advantageously less than 0.34 ml / g.

[0045] According to the invention, said zeolite Y has a Bronsted acidity greater than 600 micromole / g, preferably greater than 650 micromole / g, more preferably greater than 700 micromole / g and very preferably greater than 760 micromole / g. Preferably, said zeolite Y has a Bronsted acidity less than 1000 micromole / g.

[0046] Preferably, said zeolite Y has a silica to alumina molar ratio (SAR) of between 5 and 50, preferably between 5 and 20, and more preferably between 5 and 10.

[0047] Preferably, said zeolite Y has a mesoporous volume greater than or equal to 0.18 ml / g, preferably between 0.18 and 0.27 ml / g, preferably between 0.20 and 0.26 ml / g and very preferably between 0.22 and 0.25 ml / g.

[0048] Preferably, said support has a content of zeolite Y, and preferably of dealuminated zeolite USY, of between 15 and 80% by weight relative to the total weight of said support, preferably between 20 and 75% by weight, and preferably between 40 and 75% by weight.

[0049] Said zeolites are advantageously defined in the classification “Atlas of Zeolite Framework Types, 6th revised edition”, Ch. Baerlocher, LB Mc Cusker, DH Oison, 6th Edition, Elsevier, 2007, Elsevier".

[0050] According to a preferred embodiment of the invention, the Y zeolite having the combination of particular characteristics defined above and suitable for the use of the catalyst support used in the process according to the invention is advantageously prepared according to preparation methods known to those skilled in the art.

[0051] Advantageously, the zeolite Y having the combination of particular characteristics defined above and suitable for the implementation of the catalyst support used in the process according to the invention is obtained according to a preparation process comprising several steps. Among these steps, the mixing in an aqueous medium of at least one alkali metal, at least one organic compound R, R being a quaternary ammonium formed of carbon chains comprising between 1 and 4 carbon atoms, at least one source of silicon SiO2, and at least one source of aluminum AI2O3, makes it possible to obtain a homogeneous mixture called precursor gel. This precursor gel can undergo an optional maturing step and an optional step of adding seeds of a zeolite of structural type FAU. At the end of these optional steps, the precursor gel undergoes a hydrothermal treatment until said zeolite Y is formed.

[0052] Thus, said Y zeolite obtained has an initial crystalline parameter aO of the elementary mesh between 24.40 Å and 24.52 Å, a specific surface area measured by nitrogen physisorption according to the BET method between 850 and 1020 m2 / g, a microporous volume determined by nitrogen adsorption greater than 0.28 ml / g and a Bronsted acidity greater than 600 micromole / g.

[0053] The support can advantageously also comprise a Beta zeolite.

[0054] Beta zeolite is generally synthesized from a reaction mixture containing a structuring agent. The use of structuring agents is well known to those skilled in the art: for example, US Patent 3,308,069 describes the use of tetraethylammonium hydroxide, and US Patent 5,139,759 describes the use of the tetraethylammonium cation derived from a tetraethylammonium halide compound. Another standard method for preparing Beta zeolite is given in the book Verified Synthesis of Zeolitic Materials.

[0055] The Beta zeolite used in the support according to the invention preferably has an overall atomic ratio SAR of between 10 and 100, preferably between 20 and 50, and preferably between 20 and 30. The Beta zeolite used in the support according to the invention advantageously has a specific surface area measured by nitrogen physisorption according to the BET method of between 400 and 800 m2 / g, preferably between 500 and 750 m2 / g, and preferably between 550 and 700 m2 / g.

[0056] In the case where the support comprises a Beta zeolite, the support advantageously has a Beta zeolite content of between 2 and 40%, preferably between 5 and 35%, and more preferably between 10 and 35% by weight relative to the total weight of said support. In the case where the support comprises a Beta zeolite, the weight ratio of said Y zeolite to said Beta zeolite in the catalyst is between 1 and 40.

[0057] Preferably, the weight ratio of said Y zeolite to said Beta zeolite in the catalyst is between 1 and 20, and preferably between 1.2 and 15, and more preferably between 1.2 and 8.

[0058] This weight ratio is calculated from the dry masses of zeolites, i.e. the masses of zeolites corrected for their water content determined by measuring Loss on Ignition at 1000°C. (dry mass)

[0059] In the case where the support comprises only USY zeolite (without Beta zeolite), it is preferably made up of:

[0060] - 15 to 80%, preferably 20 to 70%, and more preferably 40 to 70%, by weight relative to the total weight of said support of a Y zeolite, preferably a dealuminated USY zeolite, having an initial crystalline parameter aO of the elementary mesh of between 24.40 Å and 24.52 Å;

[0061] - from 20 to 85% by weight, preferably between 20% and 60% by weight, and very preferably between 20% and 50% by weight relative to the total weight of said support of at least one porous mineral matrix.

[0062] In the case where the support comprises USY zeolite and Beta zeolite, it preferably consists of:

[0063] - 15 to 80%, preferably 20 to 70%, and more preferably 40 to 70%, by weight relative to the total weight of said support of a Y zeolite, preferably a dealuminated USY zeolite, having an initial crystalline parameter aO of the elementary mesh of between 24.40 Å and 24.52 Å;

[0064] - from 2 to 40%, preferably 5 to 35%, 10 to 35% by weight relative to the total weight of said support of a Beta zeolite; and

[0065] - from 5 to 83% by weight, preferably between 15% and 40% by weight, and very preferably between 20% and 40% by weight relative to the total weight of said support of at least one porous mineral matrix. Preferably, the catalyst has a Y zeolite content of between 7 and 78% by weight relative to the total weight of said catalyst.

[0066] Preferably, in the case where a Beta zeolite is present in the formulation of the catalyst, said catalyst has a Beta zeolite content of between 2 and 39% by weight relative to the total weight of said catalyst.

[0067] Preferably, said catalyst has a content of at least one porous mineral matrix of between 4 and 81% by weight relative to the total weight of said catalyst.

[0068] The hydrocracking catalyst advantageously having a Y / beta ratio within these ranges not only allows improved selectivity to be obtained towards the naphtha cut when said catalyst is used in a hydrocracking process according to the invention, but also improved activity compared to state-of-the-art catalysts.

[0069] Catalyst preparation

[0070] The catalyst is advantageously prepared according to the conventional methods used in the prior art.

[0071] In particular, the catalyst is prepared according to a preparation method comprising:

[0072] - a support preparation step including:

[0073] - the mixture of at least one porous mineral matrix with a Y zeolite having an initial crystalline parameter ao of the elementary mesh between 24.40 Å and 24.52 Å, a specific surface area measured by nitrogen physisorption according to the BET method between 850 and 1020 m2 / g, a microporous volume determined by nitrogen adsorption greater than 0.28 ml / g and a Bronsted acidity greater than 600 micromole / g, and, optionally with a Beta zeolite, the weight ratio of said Y zeolite to said Beta zeolite in the catalyst being between 1 and 40 in the case where the Beta zeolite is present and

[0074] - the shaping of said mixture;

[0075] - the introduction of at least one hydro-dehydrogenating element chosen from the group formed by the elements of group VIB of the periodic table, preferably nickel and cobalt, the non-noble elements of group VIII of the periodic table, preferably iron, cobalt, nickel, and their mixtures, and preferably nickel and cobalt, and their mixtures, onto the support by:

[0076] - addition of at least one precursor of said element during shaping so as to introduce at least part of said element,

[0077] - impregnation of the support with at least one precursor of said element,

[0078] - possibly a drying and / or calcination step at the end of the preparation of the support and / or the step of introducing at least one hydro-dehydrogenating element.

[0079] More particularly, the catalyst is prepared according to a preparation process comprising the following steps: a) preparation of the Y zeolite having the specific crystallographic characteristic claimed according to the process described above, b) preparation of the Beta zeolite in the case where a beta zeolite is present in the formulation of the catalyst according to the invention, c) mixing with a porous mineral matrix and shaping to obtain the support, d) introduction of at least one hydro-dehydrogenating element onto the support by at least one of the following methods:

[0080] - addition of at least one precursor of said element during shaping so as to introduce at least part of said element,

[0081] - impregnation of the support with at least one precursor of said hydro-dehydrogenating element,

[0082] Possibly drying and / or calcination of the products obtained at the end of each of the preparation steps a) or b) or c) or d).

[0083] The support can advantageously be shaped by any technique known to those skilled in the art. The shaping can be carried out, for example, by extrusion, by pelletizing, by the oil-drop coagulation method, by granulation on a rotating plate or by any other method well known to those skilled in the art.

[0084] The support is preferably shaped into grains of various shapes and sizes. They are generally used in the form of cylindrical or polylobed extrudates such as trilobed, quadrilobed or polylobed, straight or twisted, but can optionally be manufactured and used in the form of crushed powders, tablets, rings, balls, wheels. However, it is advantageous for the catalyst to be in the form of extrudates with a diameter of between 0.5 and 5 mm and more particularly between 0.7 and 3 mm and even more particularly between 1.0 and 2.5 mm. The shapes are cylindrical (which may or may not be hollow), twisted cylindrical, multilobed (2, 3, 4 or 5 lobes for example), rings. Any other shape can be used.

[0085] One of the preferred shaping methods consists of co-kneading said zeolites with the binder, preferably alumina, in the form of a wet gel for a few tens of minutes, preferably between 10 and 40 minutes, then passing the paste thus obtained through a die to form extrudates with a diameter preferably between 0.5 and 5 mm.

[0086] According to another of the preferred shaping methods, said zeolites can be introduced during the synthesis of the porous mineral matrix. For example, according to this preferred embodiment of the present invention, said Y and Beta zeolites are added during the synthesis of a porous mineral matrix, such as for example a silico-aluminum matrix: in this case, said zeolites can be advantageously added to a mixture composed of an alumina compound in an acid medium with a totally soluble silica compound.

[0087] The introduction of the elements of group VIB and / or VIII may optionally take place during the shaping step, by adding at least one compound of said element, so as to introduce at least part of said element.

[0088] The introduction of at least one hydro-dehydrogenating element may advantageously be accompanied by that of at least one promoter element chosen from phosphorus, boron, silicon and preferably phosphorus and optionally the introduction of an element from group VI IA and / or VB. The shaped solid is optionally dried at a temperature of between 60 and 250°C and optionally calcined at a temperature of 250 to 800°C for a period of between 30 minutes and 6 hours.

[0089] The step of introducing at least one hydro-dehydrogenating element is advantageously carried out by a method well known to those skilled in the art, in particular by one or more operations of impregnation of the shaped and calcined or dried, and preferably calcined, support with a solution containing the precursors of the elements of group VIB and / or VIII, optionally the precursor of at least one promoter element and optionally the precursor of at least one element of group VI IA and / or group VB.

[0090] Preferably, said step d) is carried out by a dry impregnation method with a solution containing the precursors of the hydro / dehydrogenating function, i.e. elements from group VIB and / or VIII, optionally followed by a drying step and preferably without a calcination step.

[0091] In the case where the catalyst of the present invention contains a non-noble metal of group VIII, the metals of group VIII are preferably introduced by one or more operations of impregnation of the shaped and calcined support, after those of group VIB or at the same time as the latter.

[0092] The introduction of at least one hydro-dehydrogenating element may then be optionally followed by drying at a temperature between 60 and 250°C and optionally by calcination at a temperature between 250 and 800°C.

[0093] The sources of molybdenum and tungsten are advantageously chosen from oxides and hydroxides, molybdic and tungstic acids and their salts, in particular ammonium salts such as ammonium molybdate, ammonium heptamolybdate, ammonium tungstate, phosphomolybdic acid, phosphotungstic acid and their salts, silicomolybdic acid, silicotungstic acid and their salts. Ammonium oxides and salts such as ammonium molybdate, ammonium heptamolybdate and ammonium tungstate are preferably used.

[0094] The sources of non-noble Group VIII elements that can be used are well known to those skilled in the art. For example, for non-noble metals, nitrates, sulfates, hydroxides, phosphates, halides such as chlorides, bromides and fluorides, and carboxylates such as acetates and carbonates will be used.

[0095] The preferred source of phosphorus is orthophosphoric acid H3PO4, but its salts and esters such as ammonium phosphates are also suitable. Phosphorus can, for example, be introduced as a mixture of phosphoric acid and a basic organic compound containing nitrogen such as ammonia, primary and secondary amines, cyclic amines, compounds of the pyridine and quinoline family, and compounds of the pyrrole family. Tungstophosphoric or tungstomolybdic acids can be used.

[0096] The phosphorus content is adjusted, without this limiting the scope of the invention, so as to form a mixed compound in solution and / or on the support, for example tungsten-phosphorus or molybdenum-tungsten-phosphorus. These mixed compounds may be heteropolyanions. These compounds may be Anderson heteropolyanions, for example.

[0097] The source of boron may be boric acid, preferably orthoboric acid H3BO3, ammonium biborate or pentaborate, boron oxide, boric esters. Boron may, for example, be introduced in the form of a mixture of boric acid, hydrogen peroxide and a basic organic compound containing nitrogen such as ammonia, primary and secondary amines, cyclic amines, compounds of the pyridine and quinoline family and compounds of the pyrrole family. Boron may be introduced, for example, by a solution of boric acid in a water-alcohol mixture.

[0098] Many sources of silicon can be used. For example, ethyl orthosilicate Si(OEt)4, siloxanes, polysiloxanes, silicones, silicone emulsions, halide silicates such as ammonium fluorosilicate (NH4)2SiF6 or sodium fluorosilicate Na2SiF6 can be used. Silicomolybdic acid and its salts, silicotungstic acid and its salts can also be used advantageously. Silicon can be added, for example, by impregnating ethyl silicate in solution in a water-alcohol mixture. Silicon can be added, for example, by impregnating a silicon compound of the silicone type or silicic acid suspended in water.

[0099] The sources of group VB elements that can be used are well known to those skilled in the art. For example, among the sources of niobium, it is possible to use oxides, such as diniobium pentaoxide Nb2O5, niobic acid Nb2O5.H2O, niobium hydroxides and polyoxoniobates, niobium alkoxides of formula Nb(OR1)3 where R1 is an alkyl radical, niobium oxalate NbO(HC2O4)5, ammonium niobate. Preferably, niobium oxalate or ammonium niobate are used.

[0100] The sources of Group VI IA elements that can be used are well known to those skilled in the art. For example, fluoride anions can be introduced in the form of hydrofluoric acid or its salts. These salts are formed with alkali metals, ammonium or an organic compound. In the latter case, the salt is advantageously formed in the reaction mixture by reaction between the organic compound and hydrofluoric acid. It is also possible to use hydrolyzable compounds that can release fluoride anions into water, such as ammonium fluorosilicate (NH4)2SiF6, silicon tetrafluoride SiF4 or sodium tetrafluoride Na2SiF6. Fluorine can be introduced, for example, by impregnation of an aqueous solution of hydrofluoric acid or ammonium fluoride.

[0101] Hydrocracking process

[0102] The catalyst according to the invention is then advantageously used in a hydrocracking process, in particular for the production of naphtha. The catalyst used in a hydrocracking process, such as the process according to the invention, may advantageously be in sulfurized form. The non-noble metals of group VIB and / or group VIII of said catalyst are therefore present in sulfurized form.

[0103] The catalysts used in the processes according to the present invention are then advantageously subjected beforehand to a sulfurization treatment making it possible to transform, at least in part, the metallic species into sulfurized form before they are brought into contact with the feedstock to be treated. This sulfurization activation treatment is well known to those skilled in the art and can be carried out by any method already described in the literature, either in-situ, i.e. in the reactor, or ex-situ.

[0104] A conventional sulfurization method well known to those skilled in the art consists of heating the catalyst in the presence of hydrogen sulfide (pure or for example under a flow of a hydrogen-hydrogen sulfide mixture) at a temperature between 150 and 800°C, preferably between 250 and 600°C, generally in a crossed-bed reaction zone.

[0105] Another subject of the present invention also relates to a process for hydrocracking at least one hydrocarbon feedstock, preferably in liquid form, of which at least 50% by weight of the compounds have an initial boiling point greater than 300°C and a final boiling point less than 650°C, at a temperature between 200°C and 480°C, at a total pressure between 1 MPa and 25 MPa, with a ratio of hydrogen volume to hydrocarbon feedstock volume of between 80 and 5000 liters per liter and at an Hourly Volume Velocity (WH) defined by the ratio of the volume flow rate of hydrocarbon feedstock, preferably liquid, to the volume of catalyst loaded into the reactor of between 0.1 and 50 h-1, in the presence of the catalyst according to the invention.Advantageously, the catalyst according to the invention is used in the hydrocracking process according to the invention after a so-called pretreatment section containing one or more hydrotreatment catalyst(s) which may be any catalyst known to those skilled in the art and which makes it possible to reduce the content of certain contaminants in the feedstock (see below) such as nitrogen, sulfur or metals. The operating conditions (WH, temperature, pressure, hydrogen flow rate, liquid, reaction configuration, etc.) of this so-called pretreatment section may be diverse and varied in accordance with the knowledge of those skilled in the art.

[0106] Charges

[0107] A wide variety of feedstocks can be treated by the hydrocracking processes according to the invention. The feedstock used in the hydrocracking process according to the invention is a hydrocarbon feedstock of which at least 50% by weight of the compounds have an initial boiling point above 300°C and a final boiling point below 650°C, preferably of which at least 60% by weight, preferably of which at least 75% by weight and more preferably of which at least 80% by weight of the compounds, have an initial boiling point above 300°C and a final boiling point below 650°C.

[0108] The feedstock is advantageously chosen from LCO (Light Cycle Oil, light gas oils from a catalytic cracking unit), atmospheric distillates, vacuum distillates such as, for example, gas oils from the direct distillation of crude oil or from conversion units such as FCC, coker or visbreaking, feedstocks from units for extracting aromatics from lubricating oil bases or from solvent dewaxing of lubricating oil bases, distillates from desulfurization or hydroconversion processes in a fixed bed or in a bubbling bed of RAT (atmospheric residues) and / or RSV (vacuum residues) and / or deasphalted oils, and deasphalted oils, paraffins from the Fischer-Tropsch process, taken alone or in a mixture.Mention may be made of feedstocks of renewable origin (such as vegetable oils, animal fats, hydrothermal conversion oil or lignocellulosic biomass pyrolysis oil) as well as plastic pyrolysis oils. The above list is not limiting. Said feedstocks preferably have a boiling point T5 greater than 300°C, preferably greater than 340°C, i.e. 95% of the compounds present in the feedstock have a boiling point greater than 300°C, and preferably greater than 340°C. The nitrogen content of the feedstocks treated in the processes according to the invention is advantageously greater than 500 ppm by weight, preferably between 500 and 10,000 ppm by weight, more preferably between 700 and 4,000 ppm by weight and even more preferably between 1,000 and 4,000 ppm by weight.The sulfur content of the feedstocks treated in the processes according to the invention is advantageously between 0.01 and 5% by weight, preferably between 0.2 and 4% by weight and even more preferably between 0.5 and 3% by weight.

[0109] The charge may optionally contain metals. The cumulative nickel and vanadium content of the charges treated in the processes according to the invention is preferably less than 1 ppm by weight.

[0110] The feedstock may optionally contain asphaltenes. The asphaltene content is generally less than 3000 ppm by weight, preferably less than 1000 ppm by weight, even more preferably less than 200 ppm by weight.

[0111] Advantageously, when the catalyst according to the invention is used after a hydrotreatment section as described above, the nitrogen, sulfur, metal or asphaltene content of the liquid injected into the process according to the invention using the catalyst according to the invention is reduced. Preferably, the organic nitrogen content of the feedstock treated in the hydrocracking process according to the invention is then, after hydrotreatment, between 0 and 200 ppm, preferably between 0 and 50 ppm, and even more preferably between 0 and 30 ppm. The sulfur content is preferably less than 1000 ppm and the asphaltene content is preferably less than 200 ppm while the metal (Ni or V) content is less than 1 ppm.

[0112] The hydrocracking process according to the invention may comprise a fractionation step between the pretreatment of the feedstock and the hydrocracking reactor(s) using the catalyst according to the invention. In the preferred case where the hydrocracking process is operated without fractionation (gas and liquid) between the pretreatment and the hydrocracking reactor(s) using the catalyst according to the invention, the nitrogen and sulfur removed from the liquid after the pretreatment are injected in the form of NH3 and H2S into the reactor(s) containing the catalyst according to the invention.

[0113] In accordance with the invention, the hydrocracking process of said hydrocarbon feedstock according to the invention is carried out at a temperature of between 200°C and 480°C, at a total pressure of between 1 MPa and 25 MPa, with a ratio of hydrogen volume to hydrocarbon feedstock volume of between 80 and 5000 liters per liter and at an Hourly Volumetric Velocity (WH) defined by the ratio of the volumetric flow rate of hydrocarbon feedstock to the volume of catalyst loaded into the reactor of between 0.1 and 50 h-1.

[0114] Preferably, the hydrocracking process according to the invention operates in the presence of hydrogen, at a temperature between 250 and 480°C, preferably between 320 and 450°C, very preferably between 330 and 435°C, under a pressure between 2 and 25 MPa, preferably between 3 and 20 MPa, at a space velocity between 0.1 and 20 h-1, preferably 0.1 and 6 h-1, preferably between 0.2 and 3 h-1, and the quantity of hydrogen introduced is such that the volume ratio liter of hydrogen / liter of hydrocarbon is between 100 and 2000 L / L.

[0115] The process can be carried out in one or two stages depending on the level of conversion of the target feedstock, with or without recycling of the unconverted fraction. The catalyst according to the invention can be used in a non-limiting manner in one or both stages of the hydrocracking process, alone or in combination with another hydrocracking catalyst.

[0116] These operating conditions used in the processes according to the invention generally make it possible to achieve conversions per pass, into products having boiling points below 340°C, and better still below 370°C, greater than 15% by weight and even more preferably between 20 and 100% by weight.

[0117] The examples illustrate the invention without limiting its scope.

[0118] EXAMPLES

[0119] Example 1 - Preparation of a comparative catalyst A

[0120] The catalyst support A is prepared by kneading-extrusion shaping of 70% by weight of USY zeolite having a mesh parameter of 24.53 Å, a silica to alumina molar ratio (SAR) of 9, a specific surface area measured by nitrogen physisorption according to the BET method of 925 m2 / g, a micropore volume determined by nitrogen adsorption of 0.32 ml / g, a mesoporous volume determined by nitrogen adsorption of 0.12 ml / g and a Bronsted acidity of 852 pmol / g in the presence of commercial boehmite (Pural SB3, Sasol). The extrudates obtained are dried at 80°C and then calcined at 600°C in humid air (5% by weight of water per kg of dry air). The calcined support comprises, on a dry basis, 70% by weight of zeolite, and 30% by weight of alumina.

[0121] Catalyst A is prepared by dry impregnation of the support thus obtained using an aqueous solution containing the elements Ni, Mo. This solution is obtained by dissolving the following precursors in water: nickel nitrate, and ammonium heptamolybdate. The quantity of precursors in solution is adjusted according to the concentrations targeted on the final catalyst. After dry impregnation, the catalyst is dried at 120°C in air.

[0122] The mass percentages in the catalyst are respectively: 15.1% by weight of molybdenum (in Mo03 form), 3.3% by weight of nickel (in NiO form) on a dry basis.

[0123] Example 2 - Preparation of a comparative catalyst B

[0124] The catalyst support B is prepared by kneading-extrusion shaping of 70% by weight of USY zeolite having a mesh parameter of 24.48 Å, a silica to alumina molar ratio (SAR) of 6, a specific surface area measured by nitrogen physisorption according to the BET method of 827 m2 / g, a micropore volume determined by nitrogen adsorption of 0.27 ml / g, a mesoporous volume determined by nitrogen adsorption of 0.16 ml / g and a Bronsted acidity of 614 pmol / g in the presence of commercial boehmite (Pural SB3, Sasol). The extrudates obtained are dried at 80°C and then calcined at 600°C in humid air (5% by weight of water per kg of dry air). The calcined support comprises, on a dry basis, 70% by weight of USY zeolite, and 30% by weight of alumina. Catalyst B is prepared by dry impregnation of the support thus obtained using an aqueous solution containing the elements Ni, Mo.This solution is obtained by dissolving the following precursors in water: nickel nitrate and ammonium heptamolybdate. The quantity of precursors in solution is adjusted according to the concentrations targeted for the final catalyst. After dry impregnation, the catalyst is dried at 120°C in air.

[0125] The mass percentages in the catalyst are respectively: 15.1% by weight of molybdenum (in Mo03 form), 3.3% by weight of nickel (in NiO form) on a dry basis.

[0126] Example 3 - Preparation of a comparative catalyst C

[0127] The catalyst support C is prepared by kneading-extrusion shaping of 70% by weight of USY zeolite having a mesh parameter of 24.48 Å, a silica to alumina molar ratio (SAR) of 6, a specific surface area measured by nitrogen physisorption according to the BET method of 847 m2 / g, a micropore volume determined by nitrogen adsorption of 0.29 ml / g, a mesoporous volume determined by nitrogen adsorption of 0.11 ml / g and a Bronsted acidity of 420 pmol / g, in the presence of commercial boehmite (Pural SB3, Sasol). The extrudates obtained are dried at 80°C and then calcined at 600°C in humid air (5% by weight of water per kg of dry air). The calcined support comprises, on a dry basis, 70% by weight of USY zeolite, and 30% by weight of alumina.

[0128] Catalyst C is prepared by dry impregnation of the support thus obtained using an aqueous solution containing the elements Ni, Mo. This solution is obtained by dissolving the following precursors in water: nickel nitrate, and ammonium heptamolybdate. The quantity of precursors in solution is adjusted according to the concentrations targeted on the final catalyst. After dry impregnation, the catalyst is dried at 120°C in air.

[0129] The mass percentages in the catalyst are respectively: 15.1% by weight of molybdenum (in Mo03 form), 3.3% by weight of nickel (in NiO form) on a dry basis.

[0130] Example 4 - Preparation of a catalyst D according to the invention

[0131] The catalyst support D is prepared by kneading-extrusion shaping of 70% by weight of USY zeolite having a mesh parameter of 24.47 Å, a silica to alumina molar ratio (SAR) of 9, a specific surface area measured by nitrogen physisorption according to the BET method of 931 m2 / g, a micropore volume determined by nitrogen adsorption of 0.31 ml / g, a mesoporous volume determined by nitrogen adsorption of 0.24 ml / g and a Bronsted acidity of 698 pmol / g in the presence of commercial boehmite Pural SB3.

[0132] The extrudates obtained are dried at 80°C and then calcined at 600°C in humid air (5% by weight of water per kg of dry air). The calcined support comprises, on a dry basis, 70% by weight of USY zeolite, and 30% by weight of alumina.

[0133] Catalyst D is prepared by dry impregnation of the support thus obtained using an aqueous solution containing the elements Ni, Mo. This solution is obtained by dissolving the following precursors in water: nickel nitrate, and ammonium heptamolybdate. The quantity of precursors in solution is adjusted according to the concentrations targeted on the final catalyst. After dry impregnation, the catalyst is dried at 120°C in air.

[0134] The mass percentages in the catalyst are respectively: 15.0% by weight of molybdenum (in Mo03 form), 3.2% by weight of nickel (in NiO form) on a dry basis.

[0135] Example 5 - Preparation of a catalyst E according to the invention

[0136] The catalyst support E is prepared by kneading-extrusion shaping of 60% by weight of USY zeolite having a mesh parameter of 24.47 Å, a silica to alumina molar ratio (SAR) of 9, a specific surface area measured by nitrogen physisorption according to the BET method of 931 m2 / g, a micropore volume determined by nitrogen adsorption of 0.31 ml / g, a mesoporous volume determined by nitrogen adsorption of 0.24 ml / g and a Bronsted acidity of 698 pmol / g, and 10% by weight of commercial Beta zeolite (CP814E, Zeolyst) having a SiO2 / AI2O3 molar ratio of 25, a specific surface area measured by nitrogen physisorption according to the BET method of 670 m2 / g, in the presence of commercial boehmite (PuralSB3, Sasol).

[0137] The extrudates obtained are dried at 80°C and then calcined at 600°C in humid air (5% by weight of water per kg of dry air). The calcined support comprises, on a dry basis, 60% by weight of USY zeolite, 10% by weight of Beta zeolite and 30% by weight of alumina, i.e. a Y / Beta weight ratio = 6 in the catalyst. After dry impregnation, the catalyst is dried at 120°C in air.

[0138] Catalyst E is prepared by dry impregnation of the support thus obtained using an aqueous solution containing the elements Ni, Mo. This solution is obtained by dissolving the following precursors in water: nickel nitrate, and ammonium heptamolybdate. The quantity of precursors in solution is adjusted according to the concentrations targeted on the final catalyst.

[0139] The mass percentages in the catalyst are respectively: 15.0% by weight of molybdenum (in Mo03 form), 3.2% by weight of nickel (in NiO form) on a dry basis.

[0140] Example 6 - Preparation of a comparative catalyst F according to SHELL patent US7611689

[0141] The catalyst support F is prepared by kneading-extrusion shaping of 70% by weight of USY zeolite having a mesh parameter of 24.46 Å, a silica to alumina molar ratio (SAR) of 8.1, a specific surface area measured by nitrogen physisorption according to the BET method of 810 m2 / g, a micropore volume determined by nitrogen adsorption of 0.27 ml / g, a mesoporous volume determined by nitrogen adsorption of 0.14 ml / g and a Bronsted acidity of 510 pmol / g in the presence of commercial boehmite (Pural SB3, Sasol). The extrudates obtained are dried at 80°C then calcined at 600°C under humid air (5% by weight of water per kg of dry air). The calcined support comprises, on a dry basis, 70% by weight of USY zeolite, and 30% by weight of alumina.

[0142] Catalyst F is prepared by dry impregnation of the support thus obtained using an aqueous solution containing the elements Ni, Mo. This solution is obtained by dissolving the following precursors in water: nickel nitrate, and ammonium heptamolybdate. The quantity of precursors in solution is adjusted according to the concentrations targeted on the final catalyst.

[0143] The mass percentages in the catalyst are respectively: 15.0% by weight of molybdenum (in Mo03 form), 3.2% by weight of nickel (in NiO form) on a dry basis.

[0144] Example 7

[0145] The performance of the catalysts described above is evaluated in hydrocracking of a feedstock comprising a vacuum distillate and gas oil fraction in one stage using an isothermal test pilot unit in downflow configuration.

[0146] This test feed undergoes hydrotreatment (HDT). After this hydrotreatment step, the test feed has a density at 15°C of 0.8755 g / mL, a residual nitrogen content of 23 ppm wt and a residual sulfur content of 16 ppm wt. The initial point of the simulated distillation for this test feed after hydrotreatment is 163.3°C and the final point is 578.7°C. The 50% wt point of the simulated distillation is at 391.7°C. In order to simulate the partial pressure of hydrogen sulfide and ammonia generated by the HDT step of the process, the test feed is supplemented with DMDS and aniline respectively so as to obtain 8820 ppm wt of sulfur and 1900 ppm wt of nitrogen in the final supplemented feed.

[0147] Each catalyst is evaluated separately and is sulfurized prior to the hydrocracking test under SRGO charge or straight run diesel, i.e. diesel from the direct distillation of petroleum with the addition of 4% by weight of dimethyl sulfide (DMDS) and 2% by weight of aniline. Sulfurization is carried out at WH of 2 h-1 (WH = Hourly Volume Velocity), an H2 / charge volume ratio of 1000 NL / L, a total pressure of 140 bar (i.e. 14.0 MPa) and a holding temperature of 350°C for 6 hours.

[0148] After sulfurization, the operating conditions are adjusted to those used for the hydrocracking test: WH of 1.5 h-1, an H2 / load volume ratio of 1000 NL / L, a total pressure of 140 bar (i.e. 14.0 MPa). The reactor temperature is adjusted to target a net conversion of the 216°C+ fraction of 65% by weight after 150 hours under load.

[0149] Net conversion is defined as the yield of the boiling point cup (or fraction) below 216°C minus the yield of the boiling point cup below 216°C present in the test charge.

[0150] The performances of the catalysts are compared with that of the catalyst D taken as reference and reported in Table 1. The relative activity in degrees Celsius (°C) is obtained by difference of temperatures between the catalyst to be evaluated and that obtained for the reference catalyst D to obtain a net conversion of 65%. Similarly the relative yield in cut 68-216°C is taken by difference of yields obtained at 65% net conversion weight of the cut 216°C+. A positive value induces a higher activity or yield. Table 1

[0151] Table 1. Characteristics and performance positioning of catalysts A to F.

[0152] The results reported in Table 1 show that catalyst D according to the invention, consisting of a USY zeolite with a mesh parameter of 24.47 Å, a BET surface area of ​​931 m2 / g, a micropore volume of 0.31 ml / g and an acidity of 698 pmol / g, exhibits a systematic gain in activity compared to comparative catalysts B and C without degradation of yield and a gain in selectivity towards the naphtha cut compared to comparative catalyst A without degradation of activity.

[0153] More particularly, we note that the comparative catalyst A having an acidity in accordance with the invention but a non-compliant mesh parameter shows a clear reduction in yield towards the naphtha cut compared to the catalyst D in accordance with the invention.

[0154] Furthermore, the addition of a Beta zeolite to the USY zeolite according to the invention demonstrates that the presence of Beta, the USY zeolite used in the catalyst according to the invention also leads to high performances both in activity and in selectivity towards the naphtha cut and superior to those obtained with catalysts of the prior art.

[0155] We note that the comparative catalyst F, having an acidity, microporous volume and SBET not in accordance with the invention, has a lower activity compared to the catalyst D in accordance with the invention.

Claims

Claims 1. Hydrocracking catalyst comprising at least one hydro-dehydrogenating element chosen from the group formed by the non-noble elements of group VIB and group VIII of the periodic table, taken alone or as a mixture, and a support comprising at least one porous mineral matrix, a Y zeolite having an initial crystalline parameter aO of the elementary mesh of between 24.40 Å and 24.52 Å, a BET specific surface area of ​​between 850 and 1020 m2 / g, a micropore volume determined by nitrogen adsorption greater than 0.28 ml / g and a Bronsted acidity greater than 600 micromole / g.

2. Catalyst according to claim 1 in which the elements of group VIII are chosen from iron, cobalt, nickel, taken alone or in a mixture and preferably from nickel and cobalt, the content of element of group VIII being between 0.5 and 8% by weight of oxide, preferably between 0.5 and 6% by weight of oxide and very preferably between 1.0 and 4% by weight of oxide, relative to the total weight of said catalyst.

3. Catalyst according to one of claims 1 or 2 in which the elements of group VIB are chosen from tungsten and molybdenum, taken alone or in a mixture, the content of element of group VIB being between 1 and 30% by weight of oxide, preferably between 2 and 25% by weight of oxide, very preferably between 5 and 20% by weight of oxide, and even more preferably between 5 and 16% by weight of oxide, relative to the total weight of said catalyst.

4. Catalyst according to one of claims 1 to 3 wherein said zeolite Y has a Bronsted acidity greater than 650 micromole / g, preferably greater than 700 micromole / g and very preferably greater than 760 micromole / g and preferably, said zeolite Y has a Bronsted acidity less than 1000 micromole / g.

5. Catalyst according to one of claims 1 to 4 in which the initial crystalline parameter aO of the elementary mesh of the zeolite Y is between 24.40 and 24.51 Å, preferably between 24.43 and 24.51 Å and very preferably between 24.45 and 24.48 Å.

6. Catalyst according to one of claims 1 to 5 in which said zeolite Y has a specific surface area measured by nitrogen physisorption according to the BET method of between 875 and 995 m2 / g, and preferably between 900 and 970 m2 / g. ZI 7. Catalyst according to one of claims 1 to 6 in which said zeolite Y has a microporous volume determined by nitrogen adsorption greater than 0.30 ml / g and advantageously greater than 0.31 ml / g and advantageously less than 0.34 ml / g.

8. Catalyst according to one of claims 1 to 7 in which said zeolite Y has a silica to alumina molar ratio (SAR) of between 5 and 50, preferably between 5 and 20, and more preferably between 5 and 10.

9. Catalyst according to one of claims 1 to 8 in which said zeolite Y has a mesoporous volume greater than or equal to 0.18 ml / g, preferably between 0.18 and 0.27 ml / g, preferably between 0.20 and 0.26 ml / g and very preferably between 0.22 and 0.25 ml / g.

10. Catalyst according to one of claims 1 to 9 wherein said catalyst also comprises a Beta zeolite.

11. Process for hydrocracking at least one hydrocarbon feedstock of which at least 50% by weight of the compounds have an initial boiling point above 300°C and a final boiling point below 650°C, at a temperature between 200°C and 480°C, at a total pressure between 1 MPa and 25 MPa, with a ratio of hydrogen volume to hydrocarbon feedstock volume between 80 and 5000 liters per liter and at an Hourly Volumetric Flow Rate (WH) defined by the ratio of the hydrocarbon feedstock volume flow rate to the volume of catalyst loaded into the reactor between 0.1 and 50 h-1, in the presence of the catalyst according to one of claims 1 to 10.

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