Hydrocracking catalysts containing zeolite Y specialized for naphtha production.

Abstract

The present invention describes a selective hydrocracking catalyst for naphtha fractions and a hydrocracking process using said catalyst, which comprises at least one hydrodehydrogenating element selected from the group consisting of elements of group VIB and non-precious group VIII of the periodic table, employed alone or as a mixture, and a support comprising at least one porous mineral matrix, gamma zeolite with a primary crystal lattice parameter a0 greater than 24.42A, and beta zeolite, the weight ratio of said gamma zeolite to said beta zeolite in the catalyst being strictly greater than 12.

Description

[Technical field]

[0001] The present invention relates to a hydrocracking catalyst based on zeolite USY and its use for the production of naphtha by hydrocracking of petroleum fractions of the vacuum distillate and gas oil type. This type of process is used in particular in projects aimed at the conversion of hydrocarbon feedstocks for the production of petrochemical intermediates and gasoline fuels. [Background technology]

[0002] Hydrocracking catalysts are generally classified on the basis of the nature of their acid functions, in particular catalysts containing amorphous acid functions of the silica-alumina type and catalysts containing zeolitic cracking functions, e.g. zeolite Y or zeolite beta.

[0003] Hydrocracking catalysts are also classified according to the main products obtained when they are used in the hydrocracking process, the two main products being middle distillates and naphtha.

[0004] Naphtha or naphtha fraction is understood to mean a petroleum fraction having a boiling point lower than the middle distillate fraction. The middle distillate fraction generally has a cut point between 150°C and 370°C, in order to maximize the production of kerosene and gas oil. However, in the case of a process specifically targeted to the production of naphtha, for example, the lower cut point of the middle distillate fraction may be increased to increase the yield of naphtha.

[0005] For this purpose, naphtha fractions can have boiling points between the boiling point of hydrocarbon compounds having six carbon atoms per molecule (or 68°C boiling point) and up to 216°C, and include gasoline fractions.

[0006] There is high demand for gasoline and naphtha fractions, which is why refiners for many years have focused on hydrocracking catalysts that are selective towards the naphtha fraction.

[0007] It is known to use catalysts based on zeolites of the FAU type to produce naphtha fractions.

[0008] Patent document 1 (Shell) describes zeolite Y of the FAU type, a catalyst containing said zeolite, its preparation and its use in hydrocracking processes. In particular, the lattice parameter of FAU zeolite is 24.40-24.50 angstroms (Å), the silica-alumina mole ratio (SAR) is 5-10 and the alkali metal content is less than 0.15% by weight. Such zeolites have been demonstrated to have high selectivity towards naphtha fractions, in particular towards heavy naphtha fractions, when they are used in hydrocracking processes.

[0009] In the patent application (Patent Document 2) (Shell), the lattice constant is 24.42-24.52 angstroms (Å), the silica-alumina molar ratio (SAR) is 10-15, and the surface area is 910-1020 m 2 The preparation of FAU zeolites with a catalytic activity of 100-150 / g is described. This series teaches that catalysts containing this zeolite are particularly selective towards naphtha fractions when used in processes for converting hydrocarbon fractions.

[0010] In the patent application (Patent Document 3) (Shell), the low lattice constant is 24.10 to 24.40 angstroms (Å), the silica-alumina molar ratio (SAR) is greater than 12, preferably 20 to 100, and the BET specific surface area is 850 m 2US Pat. No. 5,399,633 describes a hydrocracking process using a catalyst comprising zeolite Y having a molecular weight of more than 1000 s / g and a micropore volume of more than 0.28 mL / g. US Pat. No. 5,399,633 teaches that zeolites with low lattice constants are known to be selective towards middle distillates but less active than zeolites with higher lattice constants. The catalyst comprising a zeolite with low lattice constant according to the invention of US Pat. No. 5,399,633 nevertheless provides high activity combined with good selectivity towards middle distillates.

[0011] Other catalysts based on zeolite Y and zeolite beta may also be used.

[0012] Patent (UOP) describes a hydrocracking catalyst containing zeolite beta and zeolite Y, the lattice constant of zeolite Y being 24.38-24.50 angstroms (Å), the catalyst being characterized by a weight ratio of Y / beta of 5-12. The catalyst has a relatively high proportion of zeolite Y compared to the proportion of zeolite beta. These catalysts have been demonstrated to have improved selectivity and activity compared to conventional commercial catalysts. Also disclosed is a hydrocracking process using said catalyst at high temperature and pressure to convert a hydrocarbon feedstock into products having lower boiling points and lower molecular weights. In particular, the resulting products contain a majority of components boiling in the naphtha fraction temperature range (C6-216°C).

[0013] While attempting to develop a new hydrocracking catalyst selective towards naphtha fractions, the Applicant has surprisingly discovered that it is possible to obtain a hydrocracking catalyst which is obtained by combining at least one hydrodehydrogenating element selected from the group formed by the elements of group VIB and the non-noble metal elements of group VIII of the periodic table, and at least one porous mineral matrix, the initial lattice parameter a0 of the unit cell being strictly less than 24.40 Å and the BET specific surface area being between 700 and 1000 m 2It has been found that a catalyst comprising a support containing zeolite Y, the support having a micropore volume, determined by nitrogen adsorption, of greater than 0.28 mL / g and a Bronsted acidity, determined by nitrogen adsorption, of greater than 300 micromol / g, makes it possible to obtain, in particular, an improved selectivity towards naphtha fractions compared to prior art catalysts. [Prior art documents] [Patent documents]

[0014] [Patent Document 1] U.S. Patent No. 7,611,689 [Patent Document 2] WO 11 / 067258 [Patent Document 3] WO 04 / 0487988 [Patent Document 4] U.S. Patent No. 7,510,645 Summary of the Invention [Means for solving the problem]

[0015] (Subject of the Invention) More specifically, the present invention relates to a process for the production of naphtha fractions, comprising at least one hydrodehydrogenating element, selected from the group formed by the elements of group VIB and the non-noble metal elements of group VIII of the periodic table, used alone or in a mixture, and at least one porous mineral matrix, the initial lattice parameter a0 of the unit cell being strictly less than 24.40 Å and the BET specific surface area being between 700 and 1000 m. 2 and a support comprising zeolite Y having a micropore volume greater than 0.28 mL / g as determined by nitrogen adsorption and a Bronsted acidity strictly greater than 300 micromol / g.

[0016] The invention advantageously comprises at least one hydrodehydrogenating element, employed alone or in a mixture, selected from the group formed by the elements of group VIB and the non-noble metal elements of group VIII of the periodic table, and at least one porous mineral matrix, the initial lattice parameter a0 of the unit cell being less than 24.40 Å and the BET specific surface area being between 700 and 1000 m 2 and a support comprising zeolite Y having a micropore volume greater than 0.28 mL / g as determined by nitrogen adsorption and a Bronsted acidity greater than 300 micromol / g.

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

[0018] One advantage of the present invention is that it provides a hydrocracking catalyst for obtaining improved selectivity towards naphtha fractions when used in the hydrocracking process according to the invention compared to catalysts from the prior art.

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

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

[0021] The advantage of the advantageous embodiment of the present invention is that it provides a hydrocracking catalyst comprising said zeolite Y and beta zeolites having the specific characteristics claimed, in a specific Y / Beta mass ratio, which allows an improved activity as well as an improved selectivity towards naphtha fractions to be obtained when said catalyst is used in a hydrocracking process according to the invention, compared to prior art catalysts.

[0022] In the present invention, the conversion activity of a hydrocracking catalyst for naphtha production is determined by comparing the temperature that must be used during catalytic testing to produce at least 65% by weight of products with a boiling point below 216° C. The lower the temperature required, the more active the catalyst is. This temperature reduction makes it possible, for example, to limit the energy consumption of the process and increase the cycle time for using the catalyst, as well as to process less active feedstocks without modifying the processing volume and scheme.

[0023] Throughout the rest of the text, the term "specific surface area" refers to the BET specific surface area (SBET) determined by nitrogen adsorption according to standard ASTM 4365-19, established from the Brunauer-Emmett-Teller method described in The Journal of the American Chemical Society, 60, 309 (1938). Textural analysis by nitrogen adsorption also allows the micropore volume, i.e. the volume of pores with an opening of less than 2 nm, to be determined. Before the analysis, the zeolite powder is activated at 500° C. for 5 hours.

[0024] Similarly, mesopore volume is determined by nitrogen adsorption. Throughout the following text, the term "micropore" means a pore with an opening smaller than 2 nm, and "mesopore" means a pore with an opening larger than 2 nm.

[0025] Throughout the following text, the Bronsted acidity of zeolite Y is measured by adsorption of pyridine followed by thermal desorption and subsequent infrared spectroscopy (FTIR). This method is conventionally used to characterize acidic solids, such as Y zeolites, as described in the journal CA Emeis, Journal of Catalysis, 141, 347 (1993). Prior to the analysis, the zeolite powder is compressed in the form of pellets of 16 mm diameter and activated at 450° C. under secondary vacuum. The steps of introduction of pyridine in the gas phase in contact with the activated pellets and thermal desorption are carried out at 150° C. The concentration of pyridinium ions detected by FTIR after thermal desorption at 150° C. corresponds to the Bronsted acidity of the zeolite and is expressed in micromol / g.

[0026] For the purposes of the present invention, the various embodiments presented may be used alone or in combination with each other, without any limitations on the combinations.

[0027] For purposes of the present invention, various ranges of parameters for a given process, such as pressure ranges and temperature ranges, may be used alone or in combination, e.g., for purposes of the present invention, a preferred range of pressure values ​​may be combined with a more preferred range of temperature values.

[0028] In the following text, the groups of chemical elements are given according to the CAS classification (CRC Handbook of Chemistry and Physics, published by CRC Press, editor DR Lide, 81st edition, 2000-2001). For example, group VIII according to the CAS classification corresponds to metals from columns 8, 9 and 10 according to the new IUPAC classification, and group VIB corresponds to metals from column 6.

[0029] In the text that follows, the expressions "of between A and B" and "between A and B" are equivalent and mean that both limits of the interval (A, B) are included in the stated range of values. If this were not the case and if both limits were not included in the stated range, such an explanation would be provided by the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] Detailed Description of the Invention (hydrogenation / dehydrogenation function) According to the invention, the catalyst comprises at least one hydrodehydrogenating element selected from the group formed by the elements of group VIB and the non-noble metal elements of group VIII of the periodic table, used alone or in a mixture.

[0031] Preferably, the group VIII elements are selected from iron, cobalt and nickel, used alone or as a mixture, preferably nickel and cobalt. Preferably, the group VIB elements are selected from tungsten and molybdenum, used alone or as a mixture. The following combinations of metals are suitable: nickel-molybdenum, cobalt-molybdenum, nickel-tungsten, cobalt-tungsten, highly preferred: nickel-molybdenum, nickel-tungsten. It is also possible to use combinations of three metals, for example nickel-cobalt-molybdenum.

[0032] The content in the catalyst of elements from group VIII is advantageously between 0.5% and 8% by weight of oxide, preferably between 0.5% and 6% by weight of oxide, highly preferably between 1.0% and 4% by weight of oxide relative to the total weight of said catalyst. The content in the catalyst of elements from group VIB is advantageously between 1% and 30% by weight of oxide, preferably between 2% and 25% by weight of oxide, highly preferably between 5% and 20% by weight of oxide, even more preferably between 5% and 16% by weight of oxide, relative to the total weight of said catalyst.

[0033] Preferably, the catalyst used according to the invention may also contain a promoter element, which is selected from phosphorus, boron, silicon, and highly preferably is phosphorus. When the catalyst contains phosphorus, the phosphorus content is advantageously between 0.5% and 10% by weight of P2O5 oxide, preferably between 1% and 6% by weight of P2O5 oxide, and more preferably between 1% and 4% by weight of P2O5 oxide relative to the total weight of said catalyst.

[0034] (Carrier) The catalyst according to the invention comprises a support which comprises, preferably consists of, at least one porous mineral matrix, zeolite Y, preferably dealuminated zeolite USY, the initial lattice parameter a0 of the unit cell of said zeolite Y being strictly less than 24.40 Å and the BET specific surface area being between 700 and 1000 m 2 / g, micropore volume is greater than 0.28 mL / g, and Bronsted acidity is greater than 300 micromol / g.

[0035] The porous mineral matrix used in the support of the catalyst, also called binder, advantageously consists of at least one refractory oxide, preferably selected from the group formed by alumina, silica-alumina, clay, titanium oxide, boron oxide and zirconia, used alone or as a mixture. Preferably, the porous mineral matrix is ​​selected from alumina and silica-alumina, used alone or as a mixture. More preferably, the porous mineral matrix is ​​alumina. The alumina can advantageously be in any of its forms known to the skilled person. Highly preferably, the alumina is gamma alumina, for example boehmite.

[0036] Preferably, the support comprises from 15% to 55% by weight, preferably from 25% to 50% by weight, highly preferably from 25% to 40% by weight of a binder relative to the total weight of the support.

[0037] According to the invention, the initial lattice parameter a0 of the unit cell of the zeolite Y of the support is strictly less than 24.40 Å.

[0038] Preferably, the initial lattice parameter a0 of the unit cell of the zeolite Y used is less than 24.40 Å, preferably between 24.30 and 24.39 Å, preferably between 24.32 and 24.39 Å, preferably between 24.32 and 24.38 Å, highly preferably between 24.34 and 24.38 Å.

[0039] The initial lattice parameter a0 of the unit cell of a given zeolite Y is the value of the initial lattice parameter a0 of the zeolite Y used in the synthesis of the catalyst according to the invention.

[0040] The initial lattice parameter a0 of the unit cell of zeolite Y is determined by X-ray diffraction according to standard ASTM 03942-80.

[0041] According to the present invention, the specific surface area of ​​the zeolite Y is 700 to 1000 m, as measured by nitrogen physical adsorption according to the BET method. 2 / g, preferably 750 to 950 m 2 / g, preferably 800 to 950m 2 / g.

[0042] According to the invention, the micropore volume of said zeolite Y, determined by nitrogen adsorption, is greater than 0.28 mL / g, preferably greater than 0.285 mL / g and advantageously less than 0.34 mL / g.

[0043] According to the invention, the Bronsted acidity of said zeolite Y is greater than 300 micromol / g, preferably between 320 and 500 micromol / g, preferably between 325 and 425 micromol / g.

[0044] Preferably, said zeolite Y has a silica-alumina molar ratio (SAR) of 5-50, preferably 5-20, preferably >5 and <12.

[0045] Preferably, the mesopore volume of said zeolite Y is greater than 0.12 mL / g, preferably greater than 0.16 mL / g, preferably between 0.18 and 0.24 mL / g.

[0046] Preferably, the content of zeolite Y, preferably dealuminated zeolite USY, in the support is between 15% and 80% by weight, preferably between 20% and 75% by weight, preferably between 40% and 70% by weight relative to the total weight of the support.

[0047] Said zeolites are advantageously defined in the classification "Atlas of Zeolite Framework Types", 6th Revised Edition", Ch. Baerlocher, LB McCusker, DH Olson, 6th Edition, Elsevier, 2007, Elsevier.

[0048] According to a preferred embodiment of the invention, the Y zeolite, preferably a dealuminated USY zeolite, as defined above and having particular characteristics suitable for implementing the support of the catalyst used in the process according to the invention, is advantageously prepared from a Y zeolite of FAU structure type, preferably having an overall Si / Al atomic ratio of 2.3 to 2.8 after synthesis and advantageously in the NaY type after synthesis. Said Y zeolite of FAU structure type advantageously undergoes one or more steps of ion exchange followed by a dealumination step, by which the alkali cations belonging to groups IA and IIA of the periodic table present in the cation positions of the crudely synthesized Y zeolite of FAU structure type are partially or completely replaced by NH4 + Substitution with cations, preferably Na + Cation to NH4 + It becomes possible to substitute with a cation.

[0049] Alkaline cation NH4 + The partial or complete exchange of the alkali cations with NH4 is from 80% to 100%, preferably from 85% to 99.5%, more preferably from 88% to 99%. + It is understood to mean the exchange with cations. At the end of one or more ion exchange steps, the residual amount of alkali cations in the zeolite Y, preferably Na + The residual amount of cations is the alkali cations originally present in the zeolite Y, preferably Na + Relative to the amount of cations, it is advantageously between 0% and 20%, preferably between 0.5% and 15%, preferably between 1.0% and 12%.

[0050] Preferably, this step involves carrying out multiple ion exchanges with a solution containing at least one ammonium salt selected from ammonium chlorate, sulfate, nitrate, phosphate or acetate to remove the alkali cations present in the zeolite, preferably Na + The cations are at least partially removed. Preferably, the ammonium salt is ammonium nitrate NH4NO3.

[0051] Therefore, at the end of one or more ion exchange steps, the alkali cations in the zeolite Y, preferably Na + The residual content of cations is preferably such that the molar ratio of alkali cations / aluminium, preferably the Na / Al molar ratio, is 0:1 to 0:1, preferably 0:1 to 0.005:1, more preferably 0:1 to 0.008:1.

[0052] The desired ratio of alkali cation / aluminum, preferably Na / Al, is determined by the NH4 + This can be achieved by adjusting the concentration, ion exchange temperature and number of ion exchanges. + The concentration is advantageously less than 0.01 mol L -1 and 12 mol L -1 Between 1.00 and 1.00 mol L -1 and 10 mol L -1 The temperature of the ion exchange step advantageously varies between 20° C. and 100° C., preferably between 60° C. and 95° C., preferably between 60° C. and 90° C., more preferably between 60° C. and 85° C., even more preferably between 60° C. and 80° C. The number of ion exchanges advantageously varies between 1 and 10, preferably between 1 and 4.

[0053] The zeolite Y obtained, preferably of structure type FAU, can then undergo a dealumination step, which may advantageously be carried out by any method known to the person skilled in the art. Preferably, the dealumination is carried out by a thermal treatment, optionally in the presence of water vapor (or "steaming") and / or by one or more acid attacks. The acid attacks are advantageously carried out by treatment with an aqueous inorganic or organic acid solution.

[0054] Preferably, the dealumination step consists of a heat treatment followed by one or more acid attacks or only one or more acid attacks.

[0055] Preferably, the zeolite Y is subjected to a heat treatment, optionally in the presence of water vapor, the temperature at which the heat treatment is carried out is between 200°C and 900°C, preferably between 300°C and 900°C, and even more preferably between 400°C and 750°C. The duration of said heat treatment is advantageously greater than or equal to 0.5 hours, preferably between 0.5 hours and 24 hours, and highly preferably between 1 hour and 12 hours. In the case where the heat treatment is carried out in the presence of water, the volume percentage of water vapor during the heat treatment is advantageously between 5% and 100%, preferably between 20% and 100%, and highly preferably between 40% and 100%. Any volume part present that is not water vapor is formed from air. The flow rate of the gas formed from water vapor and optionally air is advantageously less than 0.2 L·h -1 ·g -1 ~10L·h -1 ·g -1 (Zeolite Y).

[0056] The heat treatment allows the extraction of aluminum atoms from the structure of zeolite Y, while keeping the overall Si / Al atomic ratio of the treated zeolite unchanged.

[0057] The step of heat treatment in the presence of water vapor may advantageously be repeated as many times as necessary to obtain a dealuminated zeolite USY suitable for mounting the support of the catalyst used in the process according to the invention and having a lattice parameter a0 of the unit cell strictly less than 24.40 Å.

[0058] The step of heat treatment, optionally in the presence of water vapor, is advantageously followed by an acid attack step which makes it possible to partially or completely remove the aluminum debris resulting from the step of heat treatment in the presence of water vapor and which partially blocks the porosity of the dealuminated zeolite; the acid attack thus makes it possible to unblock the porosity of the dealuminated zeolite.

[0059] The acid attack may advantageously be carried out by suspending the zeolite Y (possibly having undergone a previous heat treatment) in an aqueous solution containing an inorganic or organic acid. The inorganic acid may be nitric acid, sulphuric acid, hydrochloric acid, phosphoric acid or boric acid. The organic acid may be formic acid, acetic acid, oxalic acid, tartaric acid, maleic acid, malonic acid, malic acid, lactic acid or any other water-soluble organic acid. The concentration of the inorganic or organic acid in the solution is advantageously less than 0.01 mol L -1 and 2.0 mol L -1 Between 0.5 and 1.5 mol L -1 and 1.0 mol L -1 The temperature of the acid attack step is advantageously between 20° C. and 100° C., preferably between 60° C. and 95° C., preferably between 60° C. and 90° C., more preferably between 60° C. and 80° C. The duration of the acid attack is advantageously between 5 minutes and 8 hours, preferably between 30 minutes and 4 hours, preferably between 1 hour and 2 hours.

[0060] Upon completion of the step or steps of heat treatment, optionally in the presence of water vapor, and the optional acid attack step, the process for modifying zeolite Y advantageously comprises removing the alkali cations still present in the cation sites in the zeolite Y, preferably Na. + The ion exchange step is carried out in a manner similar to the ion exchange step described above.

[0061] Optionally one or more steps of heat treatment in the presence of water vapor and an optional acid attack step and an optional alkali cation, preferably Na + At the end of the step of partial or complete exchange of cations, the method for modifying the zeolite Y may include a calcination step, which makes it possible to remove organic species present in the porosity of the zeolite, such as those provided by the acid attack step or the step of partial or complete exchange of alkali cations, and in addition makes it possible to generate the proton form of the zeolite Y and to impart acidity thereto for the purposes of its application.

[0062] The calcination may advantageously be carried out in a muffle or tubular furnace, under dry air or under an inert atmosphere, in a swept or transverse bed. The calcination temperature is advantageously between 200° C. and 800° C., preferably between 450° C. and 600° C., preferably between 500° C. and 550° C. The duration of the calcination held is advantageously between 1 and 20 hours, preferably between 6 and 15 hours, preferably between 8 and 12 hours.

[0063] Therefore, the initial lattice parameter a of the unit cell of the obtained zeolite Y, preferably the dealuminated zeolite USY, is strictly less than 24.40 Å and the specific surface area, measured by nitrogen physisorption using the BET method, is between 700 and 1000 m 2 / g, the micropore volume, determined by nitrogen adsorption, is greater than 0.28 mL / g, and the Bronsted acidity is greater than 300 micromol / g.

[0064] In a preferred embodiment, the support also includes zeolite beta.

[0065] Zeolite beta 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, patent US 3 308 069 describes the use of tetraethylammonium hydroxide, and patent US 5 139 759 describes the use of tetraethylammonium cations derived from tetraethylammonium halide compounds. Another standard method for preparing zeolite beta is given in the book "Verified Synthesis of Zeolitic Materials".

[0066] The zeolite beta used in the support according to the invention preferably has an overall SAR atomic ratio of between 10 and 100, preferentially between 20 and 50, more preferably between 20 and 30. The zeolite beta used in the support according to the invention advantageously has a specific surface area, measured by nitrogen physical adsorption according to the BET method, of between 400 and 800 m 2 / g, preferably 500 to 750m 2 / g, preferably 550 to 700m 2 / g.

[0067] In the case where the support comprises zeolite beta, the support advantageously has a zeolite beta content of 2% to 40% by weight, preferably 5% to 35% by weight, preferably 10% to 35% by weight, relative to the total weight of said support.

[0068] In the case where the support comprises zeolite beta, the weight ratio of said zeolite Y to said zeolite beta in the catalyst is 1-40.

[0069] Preferably, the weight ratio of said zeolite Y to said zeolite beta in the catalyst is 1-20, preferably 1.2-15, more preferably 1.2-8.

[0070] This weight ratio is calculated from the dry mass of the zeolites, ie the mass (dry mass) of the zeolites calibrated for their water content determined by measuring the loss on ignition at 1000°C.

[0071] In the case where the support comprises only zeolite USY (without zeolite beta), it preferably consists of: - zeolite Y, preferably dealuminated zeolite USY; the initial lattice parameter a0 of the unit cell is strictly less than 24.40 Å; from 15% to 80% by weight, preferably from 20% to 70% by weight, preferably from 40% to 70% by weight, relative to the total weight of the support; at least one porous mineral matrix; representing from 20% to 85% by weight, preferably from 20% to 60% by weight, highly preferably from 20% to 50% by weight relative to the total weight of said support;

[0072] In the case where the support comprises zeolite USY and zeolite Beta, it preferably consists of: - zeolite Y, preferably dealuminated zeolite USY; the initial lattice parameter a0 of the unit cell is strictly less than 24.40 Å; from 15% to 80% by weight, preferably from 20% to 70% by weight, preferably from 40% to 70% by weight, relative to the total weight of the support; - zeolite beta; from 2% to 40% by weight, preferably from 5% to 35% by weight, or from 10% to 35% by weight, relative to the total weight of the support; and at least one porous mineral matrix; from 5% to 83% by weight, preferably from 15% to 40% by weight, highly preferably from 20% to 40% by weight, relative to the total weight of the support;

[0073] Preferably, the zeolite Y content of the catalyst is between 7% and 78% by weight relative to the total weight of said catalyst.

[0074] Preferably, in the case where zeolite beta is present in the catalyst formulation, the zeolite beta content of said catalyst is between 2% and 39% by weight relative to the total weight of said catalyst.

[0075] Preferably, the content of at least one porous mineral matrix in said catalyst is between 4% and 81% by weight relative to the total weight of said catalyst.

[0076] The hydrocracking catalyst advantageously has a Y / beta ratio within these ranges which makes it possible not only to obtain an improved selectivity towards naphtha fractions when said catalyst is used in the hydrocracking process according to the invention, but also to obtain an improved activity compared to prior art catalysts.

[0077] (Catalyst Preparation) The catalyst is advantageously prepared by conventional methods used in the art.

[0078] In particular, the catalyst is prepared by a preparation method comprising the following steps: - preparing the carrier, comprising: mixing at least one porous mineral matrix with zeolite Y and, in an advantageous embodiment in which zeolite beta is present, with zeolite beta, the initial lattice parameter a0 of the unit cell of the zeolite Y being strictly less than 24.40 Å and the specific surface area, measured by nitrogen physisorption using the BET method, being between 700 and 1000 m 2 / g, the micropore volume, as determined by nitrogen adsorption, is greater than 0.28 mL / g, the Bronsted acidity is greater than 300 micromol / g, and the weight ratio of the zeolite Y to the zeolite beta in the catalyst is 1-20; and forming the mixture; - introducing at least one hydrodehydrogenating element selected from the group formed by the elements of group VIB of the periodic table, preferably nickel and cobalt, the non-noble metal elements of group VIII of the periodic table, preferably iron, cobalt, nickel and mixtures thereof, preferably nickel and cobalt, onto the support by the following steps: - adding at least one precursor of said element during shaping to introduce at least a portion of said element, impregnating the support with at least one precursor of said element, an optional step, at the end of the preparation of the support, of drying and / or calcining and / or of introducing at least one hydrodehydrogenating element.

[0079] More specifically, the catalyst is prepared by a preparation method comprising the following steps: a) preparing a zeolite Y, preferably a dealuminated zeolite USY, having the specific crystallographic characteristics claimed by the above process, b) preparing zeolite beta in the case where it is present in the catalyst formulation according to the invention, c) mixing with a porous mineral matrix and shaping to obtain a carrier; d) introducing at least one hydrodehydrogenating element onto the support by at least one of the following methods: adding at least one precursor of said element during shaping to introduce at least a portion of said element; impregnating the support with at least one precursor of said hydrodehydrogenating element; Optionally, drying and / or calcining the product obtained at the end of each of the preparation steps a) or b) or c) or d).

[0080] The carrier may be advantageously shaped by any technique known to those skilled in the art, for example by extrusion, pelletization, the dropwise congealing (oil drop) method, granulation on a rotating plate or any other method known to those skilled in the art.

[0081] The supports are preferably formed into granules of various shapes and sizes. They are generally used in the form of cylindrical or multilobed pellets, for example trilobed, tetralobed or multilobed pellets, of straight or twisted shape, but can also be produced and used in the form of crushed powder, lozenges, rings, beads or wheels. However, the catalyst is advantageously in the form of pellets with a diameter of 0.5 to 5 mm, more particularly 0.7 to 3 mm, monolobed and more particularly 1.0 to 2.5 mm. The shape is cylindrical (which may or may not be hollow), twisted cylindrical, multilobed (for example 2, 3, 4 or 5 lobes) or annular. Any other shape may be used.

[0082] One suitable forming method consists in co-kneading said zeolite with a binder, preferably alumina, in the form of a wet gel for a few tens of minutes, preferably between 10 and 40 minutes, then forcing the paste thus obtained through a die to form pellets, the diameter of which is preferably between 0.5 and 5 mm.

[0083] According to another preferred shaping method, the zeolite can be introduced during the synthesis of the porous mineral matrix. For example, according to this preferred embodiment of the invention, the zeolites Y and Beta are added during the synthesis of a porous mineral matrix, for example a silico-aluminic matrix: in this case, the zeolite can advantageously be added to a mixture composed of an alumina compound and a completely soluble silica compound in an acid medium.

[0084] The elements of group VIB and / or group VIII may optionally be introduced during the shaping step, so as to introduce at least a portion of said elements by adding at least one compound of said elements.

[0085] The introduction of at least one hydrodehydrogenating element may advantageously be accompanied by the introduction of at least one promoter element selected from phosphorus, boron, silicon, preferably phosphorus, and optionally by the introduction of an element of group VIIA and / or group VB. The shaped solid is optionally dried at a temperature between 60° C. and 250° C. and optionally calcined at a temperature between 250° C. and 800° C. for a period between 30 minutes and 6 hours.

[0086] The step of introducing at least one hydrodehydrogenating element is advantageously carried out by methods known to those skilled in the art, in particular by one or more operations of impregnating the shaped and calcined or dried, preferably calcined, support with a solution containing precursors of elements of groups VIB and / or VIII, optionally precursors of at least one promoter element and optionally precursors of at least one element of groups VIIA and / or VB.

[0087] Preferably, said step d) is carried out by a method of dry impregnation with a solution containing hydrogenation / dehydrogenation functionalities, i.e. precursors of elements of group VIB and / or group VIII, optionally followed by a drying step, but preferably without a calcination step.

[0088] In cases where the catalyst of the invention contains a non-noble Group VIII metal, the Group VIII metal is preferably introduced in one or more operations of impregnation of the formed and calcined support, either after the introduction of Group VIB or simultaneously with the introduction of Group VIB.

[0089] The introduction of at least one hydrodehydrogenating element may then optionally be followed by drying at a temperature between 60°C and 250°C and optionally by calcination at a temperature between 250°C and 800°C.

[0090] The sources of molybdenum and tungsten are advantageously selected from the oxides and hydroxides, molybdic and tungstic acids and their salts, in particular the ammonium salts, such as ammonium molybdate, ammonium heptamolybdate and ammonium tungstate, phosphomolybdic acid, phosphotungstic acid and their salts, silicomolybdic acid, silicotungstic acid and their salts. Use is preferably made of the oxides and ammonium salts, such as ammonium molybdate, ammonium heptamolybdate and ammonium tungstate.

[0091] Sources of non-noble Group VIII elements that may be used are well known to those skilled in the art. For example, for non-noble metals, use may be made of nitrates, sulfates, hydroxides, phosphates, halides (e.g., chlorides, bromides, fluorides), carboxylates, e.g., acetates, carbonates.

[0092] The preferred source of phosphorus is orthophosphoric acid H3PO4, but its salts and esters, such as ammonium phosphate, are also suitable.Phosphorus may be introduced, for example, in the form of a mixture of phosphoric acid with nitrogen-containing basic organic compounds, such as aqueous ammonia, primary and secondary amines, cyclic amines, compounds of the pyridine and quinoline series, and compounds of the pyrrole series.Tungstophosphoric acid or tungstomolybdic acid may be used.

[0093] The phosphorus content is adjusted to form mixed compounds in the solution and / or on the support, such as tungsten-phosphorus or molybdenum-tungsten-phosphorus, without this limiting the scope of the invention. These mixed compounds can be heteropolyanions. These compounds can be, for example, Anderson heteropolyanions.

[0094] The source of boron can be boric acid, preferably orthoboric acid H3BO3, ammonium diborate or ammonium pentaborate, boron oxide or boric acid ester. Boron can be introduced, for example, in the form of a mixture of boric acid, aqueous hydrogen peroxide and nitrogen-containing basic organic compounds, such as aqueous ammonia, primary and secondary amines, cyclic amines, compounds of the pyridine and quinoline series and compounds of the pyrrole series. Boron can be introduced, for example, by a solution of boric acid in a water / alcohol mixture.

[0095] Many sources of silicon may be used. Thus, use may be made of ethyl orthosilicate Si(OEt)4, siloxanes, polysiloxanes, silicones, silicone emulsions, silicate halides, such as ammonium fluorosilicate (NH4)2SiF6 or sodium fluorosilicate Na2SiF6. Silicomolybdic acid and its salts, silicotungstic acid and its salts may be advantageously used. Silicon may be added, for example, by impregnation with a solution of ethyl silicate in a water / alcohol mixture. Silicon may be added, for example, by impregnation with a silicon compound of the silicone or silicic acid type suspended in water.

[0096] 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, use may be made of oxides such as diniobium pentoxide Nb2O5, niobate Nb2O5·H2O, niobium hydroxide and polyoxoniobates, niobium alkoxides of formula Nb(OR1)3 (wherein R1 is an alkyl group), niobium oxalate NbO(HC2O4)5, or ammonium niobate. Use is preferably made of niobium oxalate or ammonium niobate.

[0097] The sources of group VIIA 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 organic compounds. In the latter case, the salts are advantageously formed in the reaction mixture by reaction between an organic compound and hydrofluoric acid. It is also possible to use hydrolyzable compounds capable of releasing fluoride anions in water, such as ammonium fluorosilicate (NH4)2SiF6, silicon tetrafluoride SiF4 or sodium fluorosilicate Na2SiF6. Fluorine can be introduced, for example, by impregnation with an aqueous solution of hydrofluoric acid or ammonium fluoride.

[0098] (hydrocracking method) 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, for example in the process according to the invention, can advantageously be in the form of a sulfide. The Group VIB metal and / or the non-noble Group VIII metal of said catalyst are therefore present in the form of a sulfide.

[0099] The catalysts used in the process according to the invention are then advantageously subjected beforehand to a sulfurization treatment for converting, at least in part, the metallic species into the sulfide form before they are brought into contact with the feedstock to be treated. This activation treatment by sulfurization can be carried out either in situ, i.e. in the reactor, or ex situ, by any of the methods well known to the person skilled in the art and already described in the literature.

[0100] Conventional sulfurization processes well known to those skilled in the art consist of heating the catalyst in the presence of hydrogen sulfide (either of high purity or, for example, under a flow of hydrogen-hydrogen sulfide mixture) at temperatures between 150° C. and 800° C., preferably between 250° C. and 600° C., typically in a flow-through bed reaction zone.

[0101] Another subject of the invention is the process for the synthesis of at least one hydrocarbon feedstock, preferably in liquid form, 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 temperatures between 200 ° C and 480 ° C, at a total pressure between 1 MPa and 25 MPa, with a ratio of the volume of hydrogen per volume of hydrocarbon feedstock of 80 to 5000 liters / liter, at an hourly space velocity (HSV) of 0.1 to 50 h , defined by the ratio of the volumetric flow rate of the hydrocarbon feedstock, preferably in liquid form, per volume of catalyst charged in the reactor. -1 and a process for hydrocracking in the presence of the catalyst according to the invention.

[0102] Advantageously, the catalyst according to the invention is used in the hydrocracking process according to the invention after a pretreatment section containing one or more hydrotreating catalysts, which may be any catalyst known to the person skilled in the art and which makes it possible to reduce the content of certain pollutants, such as nitrogen, sulfur or metals, in the feedstock (see below). The operating conditions of this pretreatment section (HSV, temperature, pressure, hydrogen flow rate, liquids, reaction configuration, etc.) may be various and variable according to the knowledge of the person skilled in the art.

[0103] (Feed material) A wide variety of feedstocks can be processed by the hydrocracking process according to the invention. The feedstock used in the hydrocracking process according to the invention is a hydrocarbon feedstock, at least 50% by weight of the compounds of which have an initial boiling point above 300° C. and a final boiling point below 650° C., preferably at least 60% by weight, preferably at least 75% by weight, more preferably at least 80% by weight of the compounds of which have an initial boiling point above 300° C. and a final boiling point below 650° C.

[0104] The feedstocks are advantageously chosen from LCO (Light Cycle Oil, light gas oils obtained from catalytic cracking units), atmospheric distillates, vacuum distillates, for example gas oils obtained from direct distillation of crude oil or from conversion units, for example FCC, coking or visbreaking units, feedstocks originating from units for the extraction of aromatics from lubricant base stocks or feedstocks resulting from the solvent dewaxing of lubricant base stocks, distillates originating from fixed-bed or ebullated-bed desulfurization or hydroconversion processes of AR (atmospheric residues) and / or VR (vacuum residues) and / or deasphalted oils, and paraffins obtained from the Fischer-Tropsch process, used alone or in mixtures. Mention may be made of feedstocks of renewable origin (for example vegetable oils, animal fats, oils from hydrothermal conversion or pyrolysis of lignocellulosic biomass), and also plastic pyrolysis oils. The above list is not limiting. Said feedstock preferably has a boiling point T5 above 300°C, preferably above 340°C, i.e. 95% of the compounds present in the feedstock have a boiling point above 300°C, suitably above 340°C.

[0105] The nitrogen content of the feedstock treated in the process 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 4000 ppm by weight, even more preferably between 1000 and 4000 ppm by weight. The sulphur content of the feedstock treated in the process according to the invention is advantageously between 0.01% and 5% by weight, preferably between 0.2% and 4% by weight, even more preferably between 0.5% and 3% by weight.

[0106] The feedstock may optionally contain metals. The cumulative content of nickel and vanadium in the feedstock treated in the process according to the invention is preferably less than 1 ppm by weight.

[0107] The feedstock may optionally contain asphaltenes. The asphaltene content is generally less than 3000 ppm by weight, preferably less than 1000 ppm by weight, and even more preferably less than 200 ppm by weight.

[0108] Advantageously, when the catalyst according to the invention is used after the hydrotreating section described above, the nitrogen, sulfur, metal or asphaltene content in the liquid injected into the process according to the invention using the catalyst according to the invention is reduced. Preferably, the organic nitrogen content in the feedstock treated in the hydrocracking process according to the invention is then, after hydrotreating, between 0 and 200 ppm, preferably between 0 and 50 ppm, even more preferably between 0 and 30 ppm. The sulfur content is preferably less than 1000 ppm, the asphaltene content is preferably less than 200 ppm, while the metal (Ni or V) content is less than 1 ppm.

[0109] The hydrocracking process according to the invention may include 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 carried out 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.

[0110] According to the present invention, the temperature during the process for hydrocracking the hydrocarbon feedstock according to the present invention is 200°C to 480°C, the total pressure is 1MPa to 25MPa, the ratio of the volume of hydrogen per volume of the hydrocarbon feedstock is 80 to 5000 liters / liter, and the hourly space velocity (HSV), defined by the ratio of the volumetric flow rate of the hydrocarbon feedstock per volume of the catalyst loaded in the reactor, is 0.1 to 50 h -1 It is.

[0111] Preferably, the hydrocracking process according to the present invention is carried out in the presence of hydrogen at a temperature of 250° C. to 480° C., preferably 320° C. to 450° C., and more preferably 330° C. to 435° C., and at a pressure of 2 to 25 MPa, and more preferably 3 to 20 MPa, and at a space velocity of 0.1 to 20 h . -1 , preferably 0.1 to 6 hours -1 , preferably 0.2 to 3 hours -1 The amount of hydrogen introduced is set so that the volume ratio of hydrogen volume (liters) / hydrocarbon volume (liters) is 100 to 2000 L / L.

[0112] The process can be carried out in one or two steps depending on the targeted feedstock conversion degree, with or without recycling the unconverted fraction. The catalyst according to the invention can be used in a non-limiting manner in one or two steps of the hydrocracking process, alone or in combination with another hydrocracking catalyst.

[0113] The operating conditions used in the process according to the invention generally make it possible to obtain a conversion per pass of more than 15% by weight, and even more preferably between 20% by weight and 100% by weight, to products having a boiling point below 340° C., and even better below 370° C.

[0114] The examples illustrate the invention but do not limit its scope.

[0115] (Example) Example 1 - Preparation of Comparative Catalyst A The preparation by shaping of the support for catalyst A is carried out by kneading-extrusion of a commercial zeolite USY (zeolite CBV712 from Zeolyst) in the presence of 70% by weight of a commercial boehmite (Pural SB3, Sasol). The lattice parameter of the zeolite USY is 24.32 Å, the SiO2 / Al2O3 molar ratio is 22.9 and the specific surface area is 910 m2, measured by nitrogen physisorption according to the BET method. 2 / g, the micropore volume, determined by nitrogen adsorption, is 0.30 mL / g, and the Bronsted acidity is 200 μmol / g. The resulting pellets are dried at 80° C. and then calcined in moist air (5% by weight water per kg of dry air) at 600° C. The calcined support contains, on a dry basis, 70% by weight zeolite and 30% by weight alumina.

[0116] Catalyst A is prepared by dry impregnation of the resulting support with 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 amount of precursor in the solution is adjusted according to the targeted concentration on the final catalyst. After dry impregnation, the catalyst is dried in air at 120°C.

[0117] The mass percentages in the catalyst are respectively, on a dry basis, as follows: molybdenum (in the form of MoO3) 15.1 wt. %, nickel (in the form of NiO) 3.3 wt. %.

[0118] Example 2 - Preparation of Comparative Catalyst B The preparation by shaping of the support for catalyst B is carried out by kneading-extrusion in the presence of 60% by weight of zeolite USY and 10% by weight of commercial zeolite beta (zeolite CP814e, Zeolyst) in commercial boehmite (Pural SB3, Sasol). The lattice parameter of zeolite USY is 24.35 Å, the SiO2 / Al2O3 molar ratio is 12 and the specific surface area according to the BET method is 845 m 2 / g, the micropore volume, determined by nitrogen adsorption, is 0.26 mL / g, the Bronsted acidity is 290 μmol / g, the SiO2 / Al2O3 molar ratio of zeolite beta is 25, and the specific surface area, measured by nitrogen physical adsorption by the BET method, is 670 m 2 The resulting pellets are dried at 80° C. and then calcined in moist air (5% by weight water per kg of dry air) at 600° C. The calcined support contains, on a dry basis, 60% by weight of zeolite USY, 10% by weight of zeolite beta and 30% by weight of alumina, i.e. the weight ratio of USY / beta is 6.

[0119] Catalyst B is prepared by dry impregnation of the resulting support, 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 amount of precursor in the solution is adjusted according to the targeted concentration on the final catalyst. After dry impregnation, the catalyst is dried in air at 120°C.

[0120] The mass percentages in the catalyst are respectively, on a dry basis, as follows: molybdenum (in the form of MoO3) 15.1 wt. %, nickel (in the form of NiO) 3.3 wt. %.

[0121] Example 3 - Preparation of Comparative Catalyst C The preparation by shaping of the support for catalyst C is carried out by kneading-extrusion in the presence of 70% by weight of zeolite USY commercial boehmite (Pural SB3, Sasol). The lattice parameter of zeolite USY is 24.35 Å, the SiO2 / Al2O3 ratio is 12 and the specific surface area according to the BET method is 845 m 2 / g, the micropore volume, determined by nitrogen adsorption, is 0.26 mL / g, and the Bronsted acidity is 290 μmol / g. The resulting pellets are dried at 80° C. and then calcined in moist air (5% by weight water per kg of dry air) at 600° C. The calcined support contains, on a dry basis, 70% by weight of zeolite USY and 30% by weight of alumina.

[0122] Catalyst C is prepared by dry impregnation of the resulting support, 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 amount of precursor in the solution is adjusted according to the targeted concentration on the final catalyst. After dry impregnation, the catalyst is dried in air at 120°C.

[0123] The mass percentages in the catalyst are respectively, on a dry basis, as follows: molybdenum (in the form of MoO3) 15.1 wt. %, nickel (in the form of NiO) 3.3 wt. %.

[0124] Example 4 - Preparation of Comparative Catalyst D The preparation by shaping of the support for catalyst D is carried out by kneading-extrusion in the presence of 60% by weight of zeolite Y and 10% by weight of commercial zeolite beta (CP814e, Zeolyst) in commercial boehmite (Pural SB3, Sasol). The lattice parameter of zeolite Y is 24.42 Å, the SiO2 / Al2O3 molar ratio is 5.2 and the specific surface area, measured by nitrogen physisorption according to the BET method, is 725 m 2 / g, the micropore volume, determined by nitrogen adsorption, is 0.29 mL / g, the Bronsted acidity is 270 μmol / g, the SiO2 / Al2O3 molar ratio of zeolite beta is 25, and the specific surface area, measured by nitrogen physical adsorption according to the BET method, is 670 m 2 The pellets obtained are dried at 80° C. and then calcined at 600° C. in moist air (5% by weight water per kg of dry air). The calcined support contains, on a dry basis, 60% by weight of zeolite USY, 10% by weight of zeolite beta and 30% by weight of alumina, i.e. the weight ratio of USY / beta in the catalyst is 6.

[0125] Catalyst D is prepared by dry impregnation of the resulting support, 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 amount of precursors in the solution is adjusted according to the targeted concentration on the final catalyst. After dry impregnation, the catalyst is dried in air at 120° C.

[0126] The mass percentages in the catalyst are respectively, on a dry basis, as follows: molybdenum (in the form of MoO3) 15.1 wt. %, nickel (in the form of NiO) 3.3 wt. %.

[0127] Example 5 - Preparation of Comparative Catalyst E The preparation by shaping of the support for catalyst E is carried out by kneading-extrusion in the presence of 70% by weight of zeolite USY commercial boehmite (Pural SB3, Sasol). The lattice parameter of zeolite Y is 24.54 Å, the SiO2 / Al2O3 molar ratio is 5.4 and the specific surface area, measured by nitrogen physisorption according to the BET method, is 811 m2. 2 / g, the micropore volume, determined by nitrogen adsorption, is 0.28 mL / g, and the Bronsted acidity is 600 μmol / g. The resulting pellets are dried at 80° C. and then calcined in moist air (5% by weight water per kg of dry air) at 600° C. The calcined support contains, on a dry basis, 70% by weight of zeolite USY and 30% by weight of alumina.

[0128] Catalyst E is prepared by dry impregnation of the resulting support, 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 amount of precursor in the solution is adjusted according to the targeted concentration on the final catalyst. After dry impregnation, the catalyst is dried in air at 120° C.

[0129] The mass percentages in the catalyst are respectively, on a dry basis, as follows: molybdenum (in the form of MoO3) 15.1 wt. %, nickel (in the form of NiO) 3.3 wt. %.

[0130] Example 6 - Preparation of Catalyst F in Accordance with the Invention The preparation by shaping of the support for catalyst F is carried out by kneading-extrusion in the presence of 70% by weight of zeolite USY of commercial boehmite (Pural SB3). The lattice parameter of zeolite USY is 24.37 Å, the SiO2 / Al2O3 molar ratio is 11 and the specific surface area, measured by nitrogen physisorption according to the BET method, is 864 m2. 2 / g, the micropore volume, determined by nitrogen adsorption, is 0.29 mL / g, and the Bronsted acidity is 339 μmol / g.

[0131] The resulting pellets are dried at 80° C. and then calcined in moist air (5% by weight water per kg of dry air) at 600° C. The calcined support contains, on a dry basis, 70% by weight of zeolite USY and 30% by weight of alumina. After dry impregnation, the catalyst is dried in air at 120° C.

[0132] Catalyst F is prepared by dry impregnation of the resulting support with 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 amount of precursor in the solution is adjusted according to the targeted concentration on the final catalyst.

[0133] The mass percentages in the catalyst are, respectively, on a dry basis: molybdenum (in the form of MoO3) 10 wt. %, nickel (in the form of NiO) 2.0 wt. %.

[0134] Example 7 - Preparation of Catalyst G in Accordance with the Invention The preparation by shaping of the support for catalyst G is carried out by kneading-extrusion in the presence of 60% by weight of zeolite USY and 10% by weight of commercial zeolite beta (CP814e, Zeolyst) in commercial boehmite (Pural SB3, Sasol). The lattice parameter of zeolite USY is 24.37 Å, the SiO2 / Al2O3 molar ratio is 11 and the specific surface area, measured by nitrogen physisorption according to the BET method, is 864 m2. 2 / g, the micropore volume, determined by nitrogen adsorption, is 0.29 mL / g, the Bronsted acidity is 339 μmol / g, the SiO2 / Al2O3 molar ratio of the zeolite beta is 25, and the specific surface area, measured by nitrogen physical adsorption according to the BET method, is 670 m 2 / g.

[0135] The pellets obtained are dried at 80° C. and then calcined in moist air (5% by weight of water per kg of dry air) at 600° C. The calcined support contains, on a dry basis, 60% by weight of zeolite USY, 10% by weight of zeolite beta and 30% by weight of alumina, i.e. a weight ratio of Y / Beta in the catalyst=6. After dry impregnation, the catalyst is dried in air at 120° C.

[0136] Catalyst G is prepared by dry impregnation of the resulting support with 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 amount of precursor in the solution is adjusted according to the targeted concentration on the final catalyst.

[0137] The mass percentages in the catalyst are, respectively, on a dry basis: molybdenum (in the form of MoO3) 10 wt. %, nickel (in the form of NiO) 2.0 wt. %.

[0138] Example 8 - Preparation of Catalyst H in Accordance with the Invention The preparation by shaping of the support for catalyst H is carried out by kneading-extrusion in the presence of 50% by weight of zeolite USY and 20% by weight of commercial zeolite beta (CP814e, Zeolyst) in commercial boehmite (Pural SB3). The lattice parameter of zeolite USY is 24.37 Å, the SiO2 / Al2O3 molar ratio is 11 and the specific surface area, measured by nitrogen physisorption according to the BET method, is 864 m2. 2 / g, the micropore volume, determined by nitrogen adsorption, is 0.29 mL / g, the Bronsted acidity is 339 μmol / g, the SiO2 / Al2O3 molar ratio of the zeolite beta is 25, and the specific surface area, measured by nitrogen physical adsorption according to the BET method, is 670 m 2 / g.

[0139] The pellets obtained are dried at 80° C. and then calcined in moist air (5% by weight of water per kg of dry air) at 600° C. The calcined support contains, on a dry basis, 50% by weight of zeolite USY, 20% by weight of zeolite beta and 30% by weight of alumina, i.e. a weight ratio of USY / beta in the catalyst=2.5. After dry impregnation, the catalyst is dried in air at 120° C.

[0140] Catalyst H is prepared by dry impregnation of the resulting support with 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 amount of precursor in the solution is adjusted according to the targeted concentration on the final catalyst.

[0141] The mass percentages in the catalyst are, respectively, on a dry basis: molybdenum (in the form of MoO3) 10 wt. %, nickel (in the form of NiO) 2.0 wt. %.

[0142] Example 9 - Preparation of Catalyst I in Accordance with the Invention The preparation by shaping of the support for catalyst I is carried out by kneading-extrusion in the presence of commercial boehmite (Pural SB3, Sasol) with 40% by weight of zeolite USY and 30% by weight of zeolite beta (CP814e, Zeolyst). The lattice parameter of zeolite USY is 24.37 Å, the SiO2 / Al2O3 molar ratio is 11 and the specific surface area, measured by nitrogen physisorption according to the BET method, is 864 m2. 2 / g, the micropore volume, determined by nitrogen adsorption, is 0.29 mL / g, the Bronsted acidity is 339 μmol / g, the SiO2 / Al2O3 molar ratio of the zeolite beta is 25, and the specific surface area, measured by nitrogen physical adsorption according to the BET method, is 670 m 2 / g.

[0143] The pellets obtained are dried at 80° C. and then calcined in moist air (5% by weight water per kg of dry air) at 600° C. The calcined support contains, on a dry basis, 40% by weight of zeolite USY, 30% by weight of zeolite beta and 30% by weight of alumina, i.e. a weight ratio of Y / Beta in the catalyst=1.33. After dry impregnation, the catalyst is dried in air at 120° C.

[0144] Catalyst I is prepared by dry impregnation of the resulting support with 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 amount of precursor in the solution is adjusted according to the targeted concentration on the final catalyst.

[0145] The mass percentages in the catalyst are, respectively, on a dry basis: molybdenum (in the form of MoO3) 10 wt. %, nickel (in the form of NiO) 2.0 wt. %.

[0146] Example 10 The performance of the above catalysts is evaluated in a single step in the hydrocracking of feedstocks containing vacuum distillate fractions and gas oils using an isothermal test pilot unit in a downflow configuration.

[0147] The test feedstock undergoes hydrotreating (HDT). After the hydrotreating step, the density of the test feedstock at 15° C. is 0.8755 g / mL, the residual nitrogen content is 23 ppm by weight, and the residual sulfur content is 16 ppm by weight. The initial boiling point of the simulated distillation for the test feedstock after hydrotreating is 163.3° C., and the end point is at 578.7° C. The 50% point of the simulated distillation is at 391.7° C. To simulate the partial pressures of hydrogen sulfide and ammonia generated by the HDT step of the process, the test feedstock is spiked with DMDS and aniline, respectively, to obtain 8820 ppm by weight of sulfur and 1900 ppm by weight of nitrogen in the final spiked feedstock.

[0148] Each catalyst was evaluated separately and sulfided prior to hydrocracking tests under straight run gas oil (SRGO) feedstock (i.e., gas oil feedstock derived from direct distillation of crude oil) with 4 wt.% dimethyl sulfide (DMDS) and 2 wt.% aniline. The HSV for the sulfidation run was 2h. -1(HSV=Hourly Space Velocity), the H2 / feed volume ratio is 1000 NL / L, the total pressure is 140 bar (i.e., 14.0 MPa), and the holding temperature is 350° C. for 6 hours.

[0149] After sulfurization, the operating conditions are adjusted to those used for the hydrocracking tests: HSV 1.5h -1 , H2 / feed volume ratio of 1000 NL / L, total pressure of 140 bar (i.e., 14.0 MPa). The reactor temperature is adjusted to target a net conversion of 65 wt.% of the 216°C+ fraction after 150 hours from the feed.

[0150] Net conversion is defined as the yield of the cut (or fraction) boiling below 216°C minus the yield of the cut present in the test feedstock boiling below 216°C.

[0151] The performance of the catalysts is compared with that of catalyst D, taken as the reference, and is reported in Table 1. The relative activity in degrees Celsius (°C) is obtained from the difference between the temperature obtained with the catalyst under evaluation to obtain a net conversion of 65% and that obtained with reference catalyst D. Similarly, the relative yield of the 68-216°C cut is determined as the difference between the yields obtained at a net conversion of 65% by weight of the 216°C+ cut. A positive value indicates a higher activity or yield.

[0152] [Table 1]

[0153] The results reported in Table 1 indicate that the lattice constant is 24.37 Å and the BET specific surface area is 864 m 2 Catalysts F, G, H, I according to the invention, consisting of zeolite USY with a 0.01% sieve / g, a micropore volume of 0.29 mL / g, and an acidity of 339 μmol / g, are shown to show a systematic gain in yield towards the naphtha fraction compared to comparative catalysts A, B, C, D, and E.

[0154] More specifically, it is found that Comparative Catalyst A, whose lattice constant is in accordance with the present invention but whose acidity is not in accordance with the present invention, shows a clear reduction in the yield towards the naphtha fraction compared to Catalyst F, which is in accordance with the present invention.

[0155] Moreover, the addition of zeolite beta to the zeolite USY according to the invention also makes it possible to adjust the conversion activity without significantly changing the high selectivity towards naphtha fractions, thus making it possible to obtain catalysts with both improved activity and improved selectivity compared to the prior art. For example, the combination of the zeolite USY according to the invention with zeolite beta makes it possible to increase the conversion activity while still retaining a high selectivity towards naphtha fractions (catalysts F and G according to the invention). Conversely, the addition of this same zeolite beta to the zeolite USY not according to the invention does not make it possible to obtain this same gain in activity (comparative catalysts B and C).

Claims

1. A hydrocracking catalyst comprising at least one hydrodehydrogenating element selected, alone or in mixture, from the group formed by the elements of Group VIB and the non-noble metal elements of Group VIII of the Periodic Table, and a support, the support comprising at least one porous mineral matrix, zeolite Y, the unit cell of which has an initial lattice parameter a ０ is strictly less than 24.40 Å, and the BET specific surface area is between 700 and 1000 m ２ / g, the micropore volume, as determined by nitrogen adsorption, is greater than 0.28 mL / g, and the Bronsted acidity is greater than 300 micromol / g.

2. Catalyst according to claim 1, wherein the group VIII element is selected from iron, cobalt, nickel, preferably from nickel and cobalt, alone or in mixture, and the content of group VIII element is between 0.5% and 8% by weight of oxide, preferably between 0.5% and 6% by weight of oxide, highly preferably between 1.0% and 4% by weight of oxide, relative to the total weight of the catalyst.

3. Catalyst according to claim 1, wherein the Group VIB element is selected from tungsten and molybdenum, alone or in a mixture, and the content of Group VIB element is between 1% and 30% by weight of oxide, preferably between 2% and 25% by weight of oxide, highly 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 the catalyst.

4. Catalyst according to claim 1, wherein the Bronsted acidity of the zeolite Y is greater than 300 micromol / g, preferably between 320 and 500 micromol / g, preferably between 325 and 425 micromol / g.

5. The initial lattice constant a of the unit cell of zeolite Y ０ 2. The catalyst of claim 1, wherein the .lambda. is 24.30 to 24.39 Å, preferably 24.32 to 24.39 Å, preferably 24.32 to 24.38 Å, highly preferably 24.34 to 24.38 Å.

6. 10. The catalyst of claim 1, wherein the support also comprises zeolite beta, and the weight ratio of said zeolite Y to said zeolite beta in the catalyst is 1-40.

7. Catalyst according to claim 1, wherein the zeolite Y content of the catalyst is between 7 and 78% by weight relative to the total weight of the catalyst.

8. Catalyst according to claim 1, wherein zeolite beta is present in the catalyst formulation, the zeolite beta content of said catalyst being between 2 and 39% by weight relative to the total weight of said catalyst.

9. Catalyst according to claim 1, wherein the content of at least one porous mineral matrix of said catalyst is between 4 and 81% by weight relative to the total weight of said catalyst.

10. 10. A process for the hydrocracking of at least one hydrocarbon feedstock, wherein at least 50% by weight of the compounds of the hydrocarbon feedstock have an initial boiling point above 300°C and a final boiling point below 650°C, the hydrocracking being carried out in the presence of a catalyst according to any one of claims 1 to 9, wherein the temperature is between 200°C and 480°C, the total pressure is between 1 MPa and 25 MPa, the ratio of the volume of hydrogen to the volume of hydrocarbon feedstock is between 80 and 5000 liters / liter, and the hourly space velocity (HSV), defined by the ratio of the volumetric flow rate of the hydrocarbon feedstock to the volume of catalyst loaded in the reactor, is between 0.1 and 50 h －１ That's the method.