Catalyst Comprising a Silico-Aluminate Matrix and a Zeolite-Based Support, Its Preparation and Process for Hydrocracking of Hydrocarbon Feedstocks - Patent application

Abstract

The present invention describes a catalyst comprising at least one hydrogenation / dehydrogenation element selected, alone or as a mixture, from the group formed by the elements of groups VIB and VIII of the periodic table, and a support comprising at least one zeolite and one amorphous silica-alumina, the zeolite having an acid site distribution index (ASDI) greater than 0.15 and a density of acid sites (determined by H / D exchange) between 0.05 and 1 mmol / g, the support having a pore volume (measured by nitrogen porosimetry) developed in pores with a diameter between 6 nm and 11 nm less than 0.5 mL / g, a granular density measured by mercury displacement under a pressure of 0.003 MPa greater than 0.93 g / mL and a tapped packing density (TPD) greater than 0.5 g / mL and less than 0.65 g / mL. Further subject matter of the invention relates to a process for preparing said catalyst, comprising at least one step of preparing a silica-alumina gel by mixing a silica precursor with a specific alumina precursor, and to a process for hydrocracking a hydrocarbon feedstock in the presence of said catalyst.

Description

[Technical field]

[0001] The present invention relates to a catalyst comprising a silica-aluminate matrix and a zeolite-based support, and to a hydroconversion process using same.

[0002] The aim of this process is essentially to produce middle distillates, i.e. fractions having an initial boiling point of at least 150°C and a final boiling point below that of the residue, for example below 350°C or else below 390°C. [Background technology]

[0003] Hydrocracking of heavy petroleum fractions is a method frequently used in refining, which allows excess but not easily upgradeable heavy feedstocks to produce the lighter fractions that oil refiners are looking for to adapt their production to the demand structure, such as gasoline, jet fuel and light gas oil. Certain hydrocracking processes also make it possible to obtain highly refined residues that may provide excellent base stocks for oils. The advantage of catalytic hydrocracking compared to catalytic cracking is that it provides very good quality middle distillates (jet fuel and gas oil). Conversely, the gasoline produced has a much lower octane number than that obtained from catalytic cracking.

[0004] Hydrocracking is a process that derives its flexibility from three main factors: the operating conditions employed, the type of catalyst used and the fact that the hydrocracking of the hydrocarbon feedstock may be carried out in one or two steps.

[0005] The higher the catalytic activity of a catalyst, the more efficient the conversion of the feedstock. Therefore, a very active catalyst may be used at a lower temperature than a less active catalyst while maintaining the same level of conversion of the feedstock, which allows to extend the catalyst's life and reduce operating costs. The catalytic activity per unit volume of a catalyst is the product of the tapped packing density (TPD, defined below) of said catalyst and its catalytic activity per unit mass. In order to minimize the operating costs related to the mass of catalyst introduced in a given reactor volume, it is advantageous for said catalyst to have a high catalytic activity per unit mass and a low TPD. The optimal conversion of the hydrocarbon feedstock is therefore the subject of a compromise between high catalytic activity and optimized TPD.

[0006] The TPD of catalysts is related to their composition, their porous texture and their geometric shape. The hydrocracking catalysts used in hydrocracking processes are all of the bifunctional type, combining an acid function with a hydrogenation function. The acid function is generally at a temperature of 100m 2 / g to 800m 2 / g and having a surface acidity, such as halogenated (especially chlorinated or fluorinated) aluminas, combinations of oxides of boron and aluminum, amorphous silica-alumina and zeolites. The hydrogenation function is provided by one or more metals from Group VIII of the Periodic Table of the Elements, or by a combination of at least one metal from Group VIB and at least one metal from Group VIII of the Periodic Table.

[0007] The balance between the two acid functions and the hydrogenation function is one of the parameters governing the activity and selectivity of the catalyst. Catalysts provided by weak acid functions and strong hydrogenation functions are less active and generally operate at high temperatures (above 390-400°C) and low feed space velocities (HSV, expressed as the volume of feedstock to be treated per unit volume of catalyst per time, generally less than 2), but have very good selectivity for middle distillates. Conversely, catalysts provided by strong acid functions and weak hydrogenation functions are active, but have worse selectivity for middle distillates.

[0008] One type of conventional hydrocracking catalyst is based on moderately acidic amorphous supports, such as silica-alumina. These systems are used to produce good quality middle distillates and sometimes oil bases. Supports consisting of zeolites in an aluminate matrix are more acidic supports and also allow the obtaining of middle distillates, but generally with reduced selectivity. "Composite" catalyst supports consist of a mixture of one or more highly acidic zeolites, such as USY zeolites, with a moderately acidic amorphous matrix, such as silica-alumina, which have intermediate activity and selectivity.

[0009] The performance qualities of these catalysts are closely linked to their physicochemical properties, and more specifically their textural properties.

[0010] Patent document 1 describes a hydrocracking catalyst and its use in hydrocracking processes, the catalyst comprising a hydrogenation / dehydrogenation element, a Y zeolite and a silica-alumina matrix, the catalyst having a specific pore distribution with a reduced content of macropores, in particular contained in pores with a diameter of more than 500 Å, a pore volume measured by mercury porosimetry of less than 0.01 mL / g and a high TPD of the catalyst (more than 0.85 g / mL).

[0011] US Pat. No. 5,399,633 describes, in part, doped (P, B or Si) hydrocracking catalysts on supports based on zeolites and aluminosilicate matrices, which have a reduced content of macropores and a pore volume contained in pores with a diameter of more than 500 Å, as measured by mercury porosimetry, of less than 0.1 mL / g, as well as hydrocracking / hydroconversion and hydrotreating processes using said catalysts.

[0012] Patent application (Patent Document 3) describes a hydrocracking catalyst and its use in hydrocracking processes, said catalyst comprising at least one metal selected from elements from groups 6 and 8 to 10 of the periodic table of the elements and a support comprising molecular sieves, preferably Y zeolite, alumina and silica-alumina. The nanopore volume of the support expressed in pores with a size of 6 to 11 nm is 0.5 to 0.9 mL / g, and the mesopore volume of the support (pores with a size of 2 to 50 nm) is 0.7 to 1.2 mL / g. Finally, the granular density of the support is 0.7 to 0.9 g / mL. The use of a catalyst support having these properties makes it possible to obtain higher activities and better yields of middle distillates compared to the use of conventional catalyst supports not having these properties.

[0013] Patent applications (Patent Documents 4 and 5) describe a hydrocracking catalyst and its use in hydrocracking processes, said catalyst comprising a support, amorphous silica-alumina and a stabilized Y zeolite having an acid site distribution index (ASDI) of 0.02 to 0.12, the volume of macropores in said zeolite accounting for 15% to 25% of the total pore volume of said zeolite and at least one metal selected from the elements of groups 6 and 8 to 10 of the periodic table.

[0014] Patent application 6 describes a hydrocracking catalyst and its use in hydrocracking processes, the catalyst comprising a support, at least one metal from groups 6 and 8, and at least 10% by weight of a USY zeolite having an acid site density (determined by H / D exchange) of 0.350 to 0.650 mmol / g and an acid site distribution index (ASDI) of 0.05 to 0.15, the acid site density and ASDI being determined by H / D exchange at 80° C. of acidic hydroxyl groups by FTIR infrared spectroscopy. The use of a zeolite with this combination of acidities makes it possible to obtain improved selectivity for the 121° C.-288° C. cut and improved activity at 60% conversion.

[0015] Finally, a patent application (Patent Document 7) describes a support comprising Y zeolite and an amorphous inorganic oxide, the support having a unimodal pore distribution characterized by the presence of a single narrow peak in the mesopore range of 4-50 nm, a TPD of the support of 0.35-0.50 g / mL, and a pore volume expressed in pores with diameters of 4-50 nm greater than 0.4 mL / g, accounting for at least 50% of the total pore volume. [Prior art documents] [Patent documents]

[0016] [Patent Document 1] French Patent No. 2863913 [Patent Document 2] European Patent No. 1830959 [Patent Document 3] International Publication No. 2015 / 164334 [Patent Document 4] International Publication No. 2016 / 069071 [Patent Document 5] International Publication No. 2016 / 069073 [Patent Document 6] US Patent Application Publication No. 2016 / 0296922 [Patent Document 7] International Publication No. 2005 / 084799 Summary of the Invention [Means for solving the problem]

[0017] Unexpectedly, the applicant has demonstrated that a catalyst support with a specific porosity, comprising at least one silica-alumina and said zeolite, results in improved catalytic performance qualities in terms of selectivity for middle distillates when used in hydrocracking processes, compared to prior art catalysts. In particular, the specific porosity of said support results from the process for preparing said silica-alumina, and very particularly from the characteristics of the alumina precursor used in the synthesis of the silica-alumina gel.

[0018] In a preferred embodiment, the applicant has demonstrated that the use of a zeolite with a specific acidity in a catalyst support with a specific porosity, said catalyst support comprising at least one silica-alumina and said zeolite, results in improved catalyst performance qualities, when used in hydrocracking processes, in terms of activity as well as selectivity for middle distillates, compared to prior art catalysts. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Description of the Invention (Characterization techniques) In the following, 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 the metals in columns 8, 9 and 10 according to the new IUPAC classification.

[0020] The various atomic contents in the zeolite, alumina precursor, and catalyst supports are measured by X-ray fluorescence, atomic absorption spectroscopy, or inductively coupled plasma (ICP) spectroscopy, using the method most appropriate for the values ​​being measured.

[0021] In this description, in accordance with the IUPAC convention, the term "micropore" is understood to mean a pore whose diameter is less than 2 nm; "mesopore" is understood to mean a pore whose diameter is more than 2 nm and less than 50 nm, and "macropore" is understood to mean a pore whose diameter is equal to or greater than 50 nm.

[0022] The term "specific surface area" of a zeolite, support or catalyst means the BET specific surface area determined by nitrogen adsorption according to standard ASTM D 3663-78, which is established from the Brunauer-Emmett-Teller method described in the paper "The Journal of the American Chemical Society, 60, 309 (1938)".

[0023] The pore distribution measured by nitrogen adsorption was determined by the Barrett-Joyner-Halenda (BJH) model. The nitrogen adsorption-desorption isotherm according to the BJH model is described in The Journal of the American Chemical Society, 73, 373 (1951) by EP Barrett, LG Joyner and PP Halenda. In the following disclosure of the present invention, the term "nitrogen pore volume" (N2 Vpore) is understood to mean the volume measured by nitrogen adsorption for P / P0=0.99 (the pressure at which nitrogen is deemed to fill all the pores).

[0024] The quantitative analysis of the microporosity (pores with a diameter less than 2 nm) is carried out by the "t" method (Lippens-De Boer method, 1965), which corresponds to the transformation of the starting nitrogen adsorption isotherm as described in the publication "Adsorption by Powders and Porous Solids. Principles, Methodology and Applications" written by F. Rouquerol, J. Rouquerol and K. Sing, Academic Press, 1999.

[0025] The "mercury pore volume" (Hg Vpore) of supports and catalysts is understood to mean the volume measured by mercury intrusion porosimetry according to standard ASTM D4284-83, at a maximum pressure of 4000 bar (400 MPa), with a surface tension of 485 dynes / cm and a contact angle of 140°. Following the recommendations of the publication "Techniques de l'ingenieur, traite analyse et caracterisation" [Engineer's Techniques, Analysis and Characterization Papers], written by Jean Charpin and Bernard Rasneur, pages 1050-1055, the wetting angle was taken to be equal to 140°. The value above which mercury fills all the interparticle voids is set to 0.2 MPa, above which mercury is considered to penetrate into the pores of the sample. To obtain better accuracy, the value of the pore volume corresponds to the value of the pore volume measured by mercury intrusion porosimetry measured on a sample minus the value of the pore volume measured by mercury intrusion porosimetry measured on the same sample for a pressure equivalent to 0.2 MPa.

[0026] The mean diameter (mean D(Hg)) is defined as the diameter in the range of 36 Å to 1000 Å such that all pores of a size less than this diameter constitute 50% of the mercury pore volume (Hg Vpore).

[0027] To explain the pore distribution measured by nitrogen adsorption or mercury porosimetry, V(<xnm)およびV(> V(x-ynm) defines the volume expressed in pores with diameters less than or greater than x nm, respectively. V(x-ynm) defines the volume expressed in pores with diameters between x nm and ynm.

[0028] To better characterize the pore distribution, the following pore distribution criteria are defined and measured by mercury porosimetry: - volume V1 corresponds to the volume contained in pores whose diameter is less than the mean diameter minus 3 nm; - volume V2 corresponds to the volume contained in pores whose diameter is greater than or equal to the mean diameter minus 3 nm and less than the mean diameter plus 3 nm; - volume V3 corresponds to the volume contained in pores whose diameter is greater than or equal to the mean diameter plus 3 nm; - volume V4 corresponds to the volume contained within pores whose diameter is less than the mean diameter minus 1.5 nm; - volume V5 corresponds to the volume contained in pores whose diameter is equal to or greater than the mean diameter minus 1.5 nm and less than the mean diameter plus 1.5 nm; - volume V6 corresponds to the volume contained within pores whose diameter is greater than or equal to the mean diameter plus 1.5 nm;

[0029] The granular density is given by the formula gd=M / V, where M is the mass and V is the volume of the sample. This volume V of the sample is determined by measuring the volume displaced when the sample is immersed in mercury under a pressure of 0.003 MPa.

[0030] The tapped packing density (TPD) of supports and catalysts is measured as described in the study by JF Le Page et al. "Applied Heterogeneous Catalysis", Technip, Paris, 1987. A graduated cylinder of acceptable dimensions is filled by successive additions, and between each addition the catalyst is tapped by shaking the cylinder until a constant volume is achieved. This measurement is generally performed on 1000 mL of tapped catalyst in a cylinder with a height to diameter ratio close to 5:1. This measurement may preferably be performed on an automated instrument, such as an Autotap instrument sold by Quantachrome®.

[0031] The dispersibility index of boehmite gel is defined as the weight percentage of peptized alumina gel that can be dispersed by centrifugation in a polypropylene tube at 3600 G for 10 minutes. Dispersibility is measured by dispersing 10% boehmite in a suspension in water that also contains 10% nitric acid relative to the mass of boehmite. The suspension is then centrifuged at 3600 G rpm for 10 minutes. The collected sediment is dried at 100° C. overnight and then weighed. The dispersibility index is indicated by DI and is obtained by the following calculation: DI (%)=100%-mass of dried sediment (%).

[0032] The crystallite dimensions of the boehmite gel are measured by X-ray diffraction using a PANalytical X'Pert Pro diffractometer, operated in reflection and equipped with a rear monochromator using CuKα radiation (λKα1=1.5406 Å, λKα2=1.5444 Å). The crystallite dimensions are measured along the two crystallographic directions

[0020] and

[0120] using the Scherrer formula given in the reference "Scherrer after sixty years: A survey and some new results in the determination of crystallite size", JI Langford and AJC Wilson, Appl. Cryst., 11, 102-113 (1978).

[0033] The lattice parameter a0 of the unit cell of the zeolite, ie the lattice constant, is determined by X-ray diffraction according to standard ASTM 03942-80.

[0034] The Bronsted acidity of zeolites is measured by adsorption and successive thermal desorption of pyridine followed by infrared (FTIR) spectroscopy. This method is conventionally used to characterize acidic solids, such as zeolites, as described in the article CA Emeis, Journal of Catalysis, 141, 347 (1993). Before 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 micromoles / g of zeolite.

[0035] The distribution of Brønsted acid sites and the acid site distribution index (ASDI) are determined by H / D exchange and subsequent IR spectroscopy according to the method described in the paper E.J.M.Hensen et al., J.Phys.Chem.C, 114, 8363-8374 (2010). Prior to the IR measurements, the samples were heated at 400-450 °C in vacuum (<1 × 10 -5 The sample is then thermally activated at 37° C. (1000 psi) for 1 hour under 1000 psi (20 Torr). The sample is then assayed by introducing deuterated benzene and equilibrating at 80° C. IR spectra are recorded before and after exposure to analyze the hydroxyl (OH) / deuterooxyl (OD) regions.

[0036] The density of the Brønsted acid site is 2676 cm -1 (First high frequency OD (HF), 2653 cm -1 (Second high frequency OD (HF'), 2632 and 2620 cm -1 (First low frequency OD (BF), 2600 cm -1 The Brønsted acid site density is expressed in mmol / g zeolite. The acid site distribution index (ASDI) represents the content of superactive acid sites present in the zeolite and is determined as follows: ASDI = (HF'+LF') / (HF+LF) In the remainder of the text, acid site distribution and acid site density refer to Bronsted acid sites, even if this is not explicitly stated.

[0037] In the remainder of the text, 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 is not the case and if both limits are not included in the stated range, such an explanation is given by the present invention.

[0038] For purposes of the present invention, ranges of various 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 range of preferred pressure values ​​may be combined with a range of more preferred temperature values.

[0039] (Summary of the invention) One subject of the present invention is a catalyst comprising at least one hydrogenation / dehydrogenation element, chosen alone or in a mixture from the group formed by the elements from groups VIB and VIII of the periodic table, and a support comprising at least one zeolite and at least one amorphous silica-alumina, the support having: the pore volume expressed in pores with diameters between 6 nm and 11 nm, as measured by nitrogen porosimetry, is less than 0.5 mL / g; - the granular density, measured by mercury displacement under a pressure of 0.003 MPa, is greater than 0.93 g / mL; - Tapped Packing Density (TPD) is greater than 0.5 g / mL and less than 0.65 g / mL.

[0040] A further subject of the invention relates to a method for preparing said catalyst, said method comprising at least one specific step of preparing a silica-alumina gel by mixing a silica precursor with an alumina precursor having specific characteristics, in particular: - The dispersibility index is between 15% and 70%; the sodium content is between 0.003% and 2% by weight, relative to the total mass of the alumina precursor; the sulfur content is between 0.005% and 2% by weight relative to the total mass of the alumina precursor; The above step is followed by a step of mixing the silica-alumina gel with a zeolite having specific properties.

[0041] Another subject of the invention is a process for hydrocracking a hydrocarbon feedstock in the presence of said catalyst.

[0042] One advantage of the present invention is to provide a catalyst which makes it possible to obtain a better activity and a better selectivity for middle distillates when it is used in a process for hydrocracking a hydrocarbon feedstock compared to the use of prior art catalysts which do not have these properties.

[0043] Detailed Description of the Invention The catalyst according to the invention comprises at least one hydrogenation / dehydrogenation element selected, alone or in a mixture, from the group formed by the elements from groups VIB and VIII of the periodic table.

[0044] Preferably, the element from group VIII is selected from iron, cobalt, nickel, utilized alone or as a mixture, preferably from nickel and cobalt, highly preferably from nickel.

[0045] Preferably, the element from group VIB is selected from tungsten and molybdenum, utilized alone or in a mixture, preferably tungsten.

[0046] Preferably, the active phase comprised by the catalyst according to the invention comprises, preferably consists of, at least one metal from group VIB, preferably tungsten, and at least one metal from group VIII, preferably nickel.

[0047] The following metal combinations are preferred: nickel-molybdenum, cobalt-molybdenum, nickel-tungsten, cobalt-tungsten, highly preferably: nickel-tungsten. It is also possible to use combinations of three metals, for example nickel-cobalt-molybdenum.

[0048] The content in the catalyst of elements from group VIII is advantageously between 0.03% and 15% by weight of oxide, preferably between 0.5% and 10% by weight of oxide and highly preferably between 1.0% and 8% by weight of oxide relative to the total weight of said catalyst.

[0049] The content in the catalyst of elements from group VIB is advantageously between 1% and 50% by weight of oxide, preferably between 5% and 40% by weight of oxide and even more preferably between 10% and 35% by weight of oxide relative to the total weight of said catalyst.

[0050] The catalyst according to the invention may optionally comprise at least one doping element, which is deposited on the catalyst and is selected from the group formed by phosphorus, boron and silicon, in which case the content by mass of boron, silicon and phosphorus, in the form of oxides, is between 0% and 15% by weight, preferably between 0% and 10% by weight and even more advantageously between 0% and 5% by weight.

[0051] Even more preferably, the catalyst does not contain doping elements of this type.

[0052] The catalyst according to the invention may optionally comprise at least one element from group VIIB, preferably manganese, in which case the weight content of the element from group VIIB is preferably between 0.005% and 20%, preferably between 0.5% and 10%, of the compound in the form of the oxide or metal.

[0053] The catalyst according to the invention may optionally contain at least one element from group VB, preferably niobium, in which case the weight content of the element from group VIIB is preferably between 0.005% and 40%, preferably between 0.5% and 20%, of the compound in the form of the oxide or metal.

[0054] (Carrier) The support contained in the catalyst according to the invention comprises at least one zeolite and at least one amorphous silica-alumina.

[0055] Preferably, said support consists of at least one zeolite, at least one amorphous silica-alumina and optionally a binder.

[0056] The zeolites used in the support of the catalyst according to the invention are selected from Y, USY, VUSY, SDUSY, mordenite, beta, EU-1, EU-2, EU-11, Nu-87, ZSM-48 or ZBM-30 zeolites, preferably Y, ultrastable Y (USY), highly ultrastable Y (VUSY) or dealuminated ultrastable Y (SDUSY) zeolites and beta zeolites, either alone or as a mixture. Highly preferably, the zeolites are selected from Y, ultrastable Y (USY), highly ultrastable Y (VUSY) and dealuminated ultrastable Y (SDUSY) zeolites.

[0057] These designations USY, VUSY and SDUSY are common in the literature but are not intended to limit the characterization of the zeolites of the present invention to such designations.

[0058] Said zeolites are advantageously defined in the classification "Atlas of Zeolite Framework Types, 6th revised edition", Ch. Baerlocher, LBMcCusker, DH Olson, 6th Edition, Elsevier, 2007, Elsevier.

[0059] Preferably, the zeolite has an acid site distribution index (ASDI), measured by H / D exchange, greater than 0.15 and preferably less than 0.4, preferably greater than 0.17, preferentially greater than 0.19, highly preferably between 0.20 and 0.35, even more preferably between 0.20 and 0.28.

[0060] Preferably, the acid site density of the zeolite (measured by H / D exchange) is from 0.05 to 1 mmol / g, preferably from 0.3 to 0.8 mmol / g, advantageously from 0.35 to 0.65 mmol / g, and highly preferably from 0.5 to 0.6 mmol / g.

[0061] Preferably, the acidity of the zeolite, measured by infrared monitoring of thermal desorption of pyridine, is greater than 100 micromol / g, preferably greater than 150 micromol / g, suitably between 160 and 800 micromol / g, more preferably between 180 and 400 micromol / g, even more preferably between 190 and 350 micromol / g.

[0062] Preferably, the zeolite used in the catalyst support according to the invention has: - Total SiO 2 / Al 2 O 3 The molar ratio is greater than 8, preferably between about 10 and 150, suitably between 12 and 120, and even more preferably between 20 and 80; the content of alkali or alkaline earth metal cations and / or rare earth cations, preferably the sodium content, determined on a zeolite calcined at 1100° C., is less than 0.2% by weight, preferably less than 0.1% by weight, suitably less than 0.05% by weight, - The lattice parameter a0 of the unit cell is 24.10×10 -10 ~24.45×10 -10 m, preferably 24.15 x 10 -10 ~24.40×10 -10 m, preferably 24.20×10 -10 ~24.38×10 -10 m, and even more preferably 24.24 × 10 -10 ~24.35×10 -10 m, - The specific surface area is determined by the BET method and is 400 m 2 / g, preferably 550m 2 / g, preferably 700m 2 / g, even more preferably 850m 2 / g or more. a total pore volume, determined by nitrogen physisorption at P / P0=0.99, of less than 0.2 mL / g, preferably between 0.3 and 0.7 mL / g, and advantageously between 0.5 and 0.65 mL / g; the volume expressed in pores with a diameter of less than 2 nm, measured by nitrogen physisorption, represents between 20% and 95%, preferably between 40% and 80%, and advantageously between 50% and 65% of the total pore volume; the volume expressed in pores with a diameter of more than 2 nm and less than 50 nm, measured by nitrogen physisorption, represents at least 5%, preferably at least 10%, advantageously between 15% and 70%, even more preferably between 20% and 50% of the total pore volume; the volume expressed in pores with a diameter of more than 8 nm, measured by nitrogen physisorption, represents at least 0.1%, preferably at least 1% and even more preferably at least 5% of the total pore volume; the volume expressed in pores with a diameter of more than 50 nm, measured by nitrogen physisorption, represents less than 15% of the total pore volume, preferably less than 10%. In a highly preferred embodiment, the zeolite is devoid of macropores.

[0063] The above characteristics of the zeolites are those of the zeolites used in the synthesis of the support of the catalyst according to the invention.

[0064] In the case where the zeolite is a Y, USY, VUSY or SDUSY zeolite, the zeolite used in the catalyst support having the particular characteristics defined above is advantageously prepared from a Y zeolite, preferably one 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 is advantageously subjected to one or more ion exchange steps followed by one or more dealumination steps. By one or more ion exchange steps, the alkali cations belonging to groups IA and IIA of the periodic table present in the cation positions in the crudely synthesized Y zeolite are replaced by NH 4 + Cation, preferably Na + Cation is NH 4 + It is possible for the cation to be partially or completely substituted.

[0065] NH 4 +The partial or total exchange of the alkali cations with cations is preferably from 80% to 100%, more preferably from 85% to 99.5%, and even more preferably from 88% to 99% of the alkali cations with NH 4 + It is understood to mean exchange with cations. At the end of one or more ion exchange steps, the remaining amount of alkali cations in the Y zeolite, preferably Na + The residual amount of cations is the amount of alkali cations initially present in the Y zeolite, preferably Na + Relative to the amount of cations, it is advantageously between 0% and 20%, preferably between 0.5% and 15%, and suitably between 1.0% and 12%.

[0066] 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 + Preferably, the ammonium salt is ammonium nitrate NH 4 NO 3 It is.

[0067] The desired alkali cation / aluminum ratio, preferably the Na / Al ratio, is determined by the NH 4 + The NH concentration of the ion exchange solution can be adjusted by adjusting the concentration, ion exchange temperature and the number of ion exchanges. 4 + 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 is advantageously between 20 and 100° C., preferably between 60 and 95° C., suitably between 60 and 90° C., more preferably between 60 and 85° C., and even more preferably between 60 and 80° C. The number of ion exchanges advantageously varies between 1 and 10, preferably between 1 and 4.

[0068] The Y zeolite obtained may then undergo one or more dealumination steps, which may advantageously be carried out by any of the methods known to those skilled in the art. Preferably, the dealumination is carried out by heat treatment, optionally in the presence of water vapor (or "steaming"), and / or by one or more acid attacks, which are advantageously carried out by treatment with aqueous inorganic or organic acid solutions.

[0069] Preferably, the dealumination step involves a heat treatment followed by one or more acid attacks, or only one or more acid attacks.

[0070] Preferably, the Y zeolite is subjected to a heat treatment, optionally in the presence of steam, at a temperature between 200 and 900°C, preferably between 300 and 900°C, and even more preferably between 400 and 750°C. The duration of said heat treatment is advantageously greater than 0.5 hours, preferably between 0.5 and 24 hours, and highly preferably between 1 and 12 hours. In the case where the heat treatment is carried out in the presence of water, the volumetric percentage of steam during the heat treatment is advantageously between 5% and 100%, preferably between 20% and 100%, and highly preferably between 40% and 100%. Any volumetric part that is not steam is formed from air. The flow rate of the gas formed from steam and optionally air is advantageously less than 0.2 L·h per g of Y zeolite weight. -1 ~10L·h -1 It is.

[0071] The heat treatment allows the extraction of aluminum atoms from the structure of Y zeolite while keeping the overall Si / Al atomic ratio of the treated zeolite unchanged.

[0072] The step of heat treatment in the presence of steam may advantageously be repeated as many times as necessary to obtain a Y zeolite suitable for implementing the support of the catalyst used in the process according to the invention and having the characteristics as claimed.

[0073] The step of heat treatment, optionally in the presence of steam, is advantageously followed by an acid attack step, which makes it possible to partially or completely remove aluminate debris resulting from the step of heat treatment in the presence of steam, which may partially block the porosity of the dealuminated zeolite; the acid attack makes it possible to leave the porosity of the dealuminated zeolite unblocked.

[0074] The acid attack may advantageously be carried out by suspending the Y zeolite, possibly previously subjected to a heat treatment, in an aqueous solution containing a mineral or organic acid. The mineral 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 mineral 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 and 100° C., preferably between 60 and 95° C., suitably between 60 and 90° C., and more preferably between 60 and 80° C. The duration of the acid attack is advantageously between 5 minutes and 8 hours, preferably between 30 minutes and 4 hours, and suitably between 1 hour and 2 hours.

[0075] Upon completion of the step or steps of heat treatment, optionally in the presence of steam, and the optional step of acid attack, the process for modifying the Y zeolite advantageously comprises removing the alkali cations, preferably Na, still present in the cation sites in the Y zeolite. + The ion exchange step is carried out in the same manner as the ion exchange step described above.

[0076] Optionally one or more steps of heat treatment in the presence of steam 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 Y zeolite may include a calcination step, which makes it possible to remove organic species present in the porosity of the zeolite, for example those provided by the acid attack step or by the step of partial or complete exchange of alkali cations, and which further makes it possible to generate the proton form of the Y zeolite and to endow it with acidity for the purposes of its application.

[0077] Calcination may advantageously be carried out in a muffle or tubular furnace, under dry air or in an inert atmosphere, in a swept or transverse bed. The calcination temperature is advantageously between 200 and 800° C., preferably between 450 and 600° C., and advantageously between 500 and 550° C. The duration of the calcination hold is advantageously between 1 and 20 hours, preferably between 6 and 15 hours, and advantageously between 8 and 12 hours.

[0078] The Y zeolite, preferably USY zeolite, obtained therefore advantageously has an acid site distribution index (ASDI) of more than 0.15, an acid site density (determined by H / D exchange) of 0.05-1 mmol / g, and the characteristics defined above.

[0079] Preferably, the weight content of zeolite in the support is generally between 0.1% and 60% by weight, preferably between 1% and 30% by weight, suitably between 2% and 15% by weight, more preferably between 3% and 12% by weight, even more preferably between 4% and 10% by weight, relative to the total weight of said support.

[0080] According to the present invention, the support also comprises amorphous silica-alumina.

[0081] The weight content of silica-alumina in the support is preferably 1% to 99.9% by weight, preferably 20% to 98% by weight, and suitably 40% to 96% by weight, relative to the total weight of said support.

[0082] Silica in silica-alumina (SiO 2The mass content of ) is 5% by weight to 95% by weight, preferably 10% by weight to 70% by weight, suitably 15% by weight to 60% by weight, and even more preferably 20% by weight to 50% by weight.

[0083] According to the process for preparing the catalyst according to the invention, said amorphous silica-alumina is obtained by reaction of a silica precursor with a specific alumina precursor having the characteristics claimed, and according to the preparation process detailed below, obtaining a silica-alumina gel, its shaping with zeolite, as well as thermal and hydrothermal treatments that make it possible to reach the characteristics of the support mentioned above are described.

[0084] According to the invention, the carrier comprises: the pore volume contained in pores having a diameter between 6 nm and 11 nm, as measured by nitrogen physisorption, is less than 0.5 mL / g; - the granular density is greater than 0.93 g / mL, measured by mercury displacement under a pressure of 0.003 MPa; - Tapped Packing Density (TPD) is greater than 0.5 g / mL and less than 0.65 g / mL.

[0085] Suitably, the support has a pore volume contained in pores having a diameter of more than 6 nm and less than 11 nm, measured by nitrogen physisorption, of 0.05 to 0.45 mL / g, preferably 0.1 to 0.35 mL / g.

[0086] Preferably, the granular density of the support is 0.95 to 1.5 g / mL, and more preferably 0.96 to 1.2 g / mL, measured by mercury displacement under a pressure of 0.003 MPa.

[0087] Preferably, the tapped packing density (TPD) of the support is 0.53 to 0.62 g / mL.

[0088] Said support of the catalyst according to the invention advantageously also has the following characteristics: - Specific surface area is determined by the BET method and is between 100 and 600 m 2 / g, preferably 150 to 450 m2 / g, more preferably 250 to 400m 2 / g, a total pore volume, measured by nitrogen porosimetry, of more than 0.45 mL / g, preferably between 0.5 and 1 mL / g, even more preferably between 0.6 and 0.7 mL / g; so that the volume expressed in pores with a diameter of more than 2 nm and less than 50 nm, measured by nitrogen physisorption, represents less than 99.9%, preferably between 40% and 99.5%, suitably between 80% and 99% of the total pore volume, and so that the volume expressed in pores with a diameter of less than 2 nm, measured by nitrogen physisorption, represents at least 0.1%, preferably between 0.2% and 50%, advantageously between 0.5% and 30%, even more preferably between 0.8% and 15% of the total pore volume, a total pore volume, measured by mercury porosimetry, of more than 0.45 mL / g, preferably between 0.5 and 1 mL / g, even more preferably between 0.5 and 0.75 mL / g; the pore volume contained in pores with a diameter of more than 14 nm, measured by mercury porosimetry, is less than 0.35 mL / g, preferably less than 0.25 mL / g; the pore volume contained in pores with a diameter of more than 16 nm, as measured by mercury porosimetry, is less than 0.3 mL / g, preferably less than 0.2 mL / g; the pore volume contained in pores with a diameter of more than 20 nm, measured by mercury porosimetry, is less than 0.15 mL / g, preferably less than 0.1 mL / g; the pore volume contained in pores with a diameter of more than 50 nm, measured by mercury porosimetry, is less than 0.01 mL / g, preferably less than 0.005 mL / g, and suitably this volume is 0; - a multimodal pore size distribution, measured by mercury porosimetry, in the domain of pores with a diameter between 4 and 50 nm, i.e. having at least two distinct peaks or one broad peak with one or more shoulders; with an average pore diameter between 4 and 50 nm, preferably between 5 and 20 nm, even more preferably between 6 and 16 nm; the ratio of the volume V2 defined above to the total pore volume; these two volumes are measured by mercury porosimetry; less than 0.8, preferably less than 0.7, even more preferably between 0.2 and 0.6, - preferably, the volume V3 as defined above is greater than 0.05 mL / g, advantageously greater than 0.06 mL / g and even more preferably between 0.07 and 0.35 mL / g; the ratio between the volume V5 and the volume V2 defined above is less than 0.8, preferably less than 0.7 and even more preferably between 0.2 and 0.6; Preferably, the volume V6 as defined above is greater than 0.05 mL / g, advantageously greater than 0.1 mL / g and even more preferably between 0.15 and 0.5 mL / g.

[0089] The carrier may optionally include a binder.

[0090] The 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 binder is alumina. Alumina can advantageously be in any of its forms known to the skilled artisan. Highly preferably, the alumina is selected from the group assembled from alpha, rho, chi, kappa, eta, gamma, theta and delta aluminas, preferably from gamma, theta and delta aluminas. In the case where the support comprises alumina, the weight content of alumina in the support of the catalyst according to the invention is preferably between 1% and 70% by weight, preferably between 2% and 60% by weight, even more preferably between 5% and 50% by weight, relative to the total weight of the support.

[0091] (Catalyst Characteristics) The catalyst according to the invention advantageously has the following characteristics: TPD: 0.5 to 1.5 g / mL, preferably 0.55 to 1.2 g / mL, more preferably 0.65 to 1 g / mL, even more preferably 0.7 to 0.85 g / mL, - Specific surface area; determined by BET method; 600 m 2 / g, preferably 50 to 450 m 2 / g, more preferably 170 to 350 m 2 / g, - total pore volume; measured by nitrogen porosimetry; greater than 0.2 mL / g, preferably between 0.25 and 0.80 mL / g, even more preferably between 0.35 and 0.55 mL / g; - total pore volume; measured by mercury porosimetry; greater than 0.2 mL / g, preferably between 0.25 and 0.75 mL / g, even more preferably between 0.3 and 0.55 mL / g; - a multimodal pore size distribution; measured by mercury porosimetry; in the domain of pores with diameters between 4 and 50 nm; i.e. having at least two distinct peaks or one broad peak with one or more shoulders; the average pore diameter is between 4 and 50 nm, preferably between 5 and 20 nm, even more preferably between 6 and 16 nm; the ratio of the volume V2 defined above to the total pore volume; these two volumes are measured by mercury porosimetry; less than 0.8, preferably less than 0.6, even more preferably between 0.2 and 0.55; preferably, the volume V3 as defined above is greater than 0.04 mL / g, advantageously between 0.05 and 0.45 mL / g and even more preferably between 0.1 and 0.25 mL / g; the ratio between the volume V5 and the volume V2; as defined above; less than 0.8, preferably less than 0.6, even more preferably between 0.2 and 0.55, preferably a volume V6; as defined above; greater than 0.05 mL / g, preferably greater than 0.1 mL / g, even more preferably between 0.1 and 0.4 mL / g, - a pore volume preferably contained in pores with a diameter of more than 14 nm; measured by mercury porosimetry; less than 0.3 mL / g, preferably less than 0.2 mL / g; - a pore volume preferably contained in pores with a diameter of more than 16 nm; less than 0.25 mL / g, preferably less than 0.15 mL / g; - the pore volume contained preferably in pores with a diameter of more than 20 nm; measured by mercury porosimetry; less than 0.15 mL / g, preferably less than 0.1 mL / g; the pore volume contained in pores with a diameter of more than 50 nm; measured by mercury porosimetry; less than 0.005 mL / g, preferably less than 0.003 mL / g; suitably, this volume is 0; the ratio of the pore volume contained in pores with a diameter of more than 50 nm to the total pore volume; these two volumes are measured by mercury porosimetry; is less than 2%, preferably less than 1% and suitably this ratio is 0; the ratio of the pore volume contained in pores with a diameter of more than 8 nm and less than 20 nm to the total pore volume; these two volumes are measured by mercury porosimetry; is more than 35%, preferably between 40% and 90%, even more preferably between 55% and 75%; the ratio of the pore volume contained in pores with a diameter of more than 20 nm and less than 50 nm to the total pore volume; these two volumes are measured by mercury porosimetry; less than 35%, preferably less than 25%, even more preferably less than 20%.

[0092] The weight content of the support in the catalyst is generally greater than 5% by weight, advantageously greater than 15% by weight, preferably between 40% and 95% by weight and even more preferably between 65% and 90% by weight, relative to the total weight of said catalyst.

[0093] The silica-alumina content by weight in the catalyst generally ranges from 1% to 99% by weight, advantageously from 10% to 85% by weight and preferably from 40% to 75% by weight relative to the total weight of said catalyst.

[0094] In the case where the support comprises an aluminate binder, the weight content of alumina in the catalyst is generally between 0.5% and 70% by weight, advantageously between 1% and 60% by weight and preferably between 3% and 50% by weight relative to the total weight of the catalyst.

[0095] The weight content of zeolite in the catalyst is generally between 0.1% and 30% by weight, advantageously between 0.2% and 20% by weight, preferably between 0.5% and 10% by weight, more preferably between 1% and 9% by weight and even more preferably between 1.5% and 8% by weight, relative to the total weight of said catalyst.

[0096] (Preparation method) Another subject of the invention is a process for preparing the catalyst according to the invention.

[0097] In particular, another subject of the invention is a process for preparing a catalyst according to the invention, comprising at least the following steps: a) preparing a silica-alumina gel by mixing a silica precursor with an alumina precursor; the alumina precursor having: · Dispersibility index: 15%~70%, Sodium content: 0.003% to 2% by weight relative to the total mass of the alumina precursor; Sulfur content: 0.005-2% by weight relative to the total mass of the alumina precursor; b) mixing at least one zeolite with a silica-alumina gel; the zeolite has an acid site distribution index (ASDI) greater than 0.15, as measured by H / D exchange; c) shaping the resulting mixture, optionally in the presence of an aluminate binder; d) at least one step of drying the shaped material; e) at least one step of thermal and / or hydrothermal treatment of the dried material; obtaining a support; f) introducing onto the support at least one hydrogenation / dehydrogenation element selected from the group formed by the elements from group VIB of the periodic table and the non-noble metal elements from group VIII of the periodic table; g) at least one step of drying the impregnated support; and e) optionally at least one step of thermal and / or hydrothermal treatment of the impregnated and dried support; to obtain said catalyst.

[0098] The characteristics of the support mentioned above correspond to the support obtained at the end of step e).

[0099] The above catalyst properties correspond to the catalyst optionally obtained upon completion of step h) in the case where steps g) and h) are performed.

[0100] (Step a)) According to the invention, the method comprises a step a) of preparing a silica-alumina gel by mixing a silica precursor with an alumina precursor, the alumina precursor having: - dispersibility index: 15% to 70%, preferably 30% to 70%, even more preferably 50% to 68%, sodium content: from 0.003% to 2% by weight relative to the total mass of the alumina precursor, preferably from 0.005% to 1% by weight, even more preferably from 0.006% to 0.1% by weight, Sulfur content: from 0.005% to 2% by weight relative to the total mass of the alumina precursor, preferably from 0.01% to 1% by weight, even more preferably from 0.02% to 0.2% by weight relative to the total mass of the alumina precursor.

[0101] The use of an alumina precursor having the claimed characteristics in step a) of preparing the silica-alumina gel makes it possible to obtain a particular porosity of the support.

[0102] Preferably, the alumina precursor is composed of crystallites, the sizes of which are obtained by the Scherrer formula in X-ray diffraction along the crystallographic directions

[0020] and

[0120] are 2-20 nm and 2-35 nm, respectively. Preferably, the crystallite size of the alumina precursor along the crystallographic direction

[0020] is 2-15 nm, and the crystallite size along the crystallographic direction

[0120] is 2-30 nm.

[0103] The alumina precursor advantageously has the general formula Al 2 O 3 nH 2 O. It is in particular possible to use aluminum hydrates, such as hydrazirite, gibbsite, bayerite, boehmite, pseudoboehmite and amorphous or essentially amorphous alumina gels. More preferentially used aluminum hydrates Al 2 O 3 nH 2 O is boehmite.

[0104] Said alumina precursor may advantageously be prepared according to any of the methods known to those skilled in the art. Depending on the acidic or basic nature of the initial aluminum-based compound, the aluminum hydrate is precipitated using a base or an acid, for example selected from the abovementioned hydrochloric acid, sulfuric acid, sodium hydroxide or the abovementioned basic or acidic compounds of aluminum. The two reactants may be aluminum sulfate and sodium aluminate. For an example of the preparation of alpha-alumina monohydrate using aluminum sulfate and sodium aluminate, reference may be made in particular to patent US4154812.

[0105] The silica precursor may be selected from the group formed by water-soluble alkaline silicates, silicic acid, silicic acid sol, cationic silicon salts such as hydrated sodium metasilicate, ammoniacal or alkaline Ludox®, quaternary ammonium silicates. The silica sol may be prepared according to any method known to those skilled in the art. Preferably, a decationized orthosilicic acid solution is prepared from the water-soluble alkaline silicates by ion exchange on a resin.

[0106] The silicic acid sol may be prepared according to any method known to those skilled in the art. Preferably, the silicic acid sol is prepared from an alkaline silicate in an aqueous solution by ion exchange on an ion exchange resin. The SiO in the silicic acid sol 2The content is 20 to 120 g / L, preferably 30 to 90 g / L, and even more preferably 40 to 80 g / L.

[0107] The alumina precursor according to the invention is advantageously dispersed in water contained in a vigorously stirred reactor to give alumina Al 2 O 3 A content of 4-15 g / L, preferably 5-12 g / L, and suitably 6-10 g / L per liter of suspension volume is achieved. The suspension is advantageously acidified with nitric acid to achieve a pH of 2-6, preferably 3-5, and then the silica precursor is added at ambient temperature, while maintaining vigorous stirring.

[0108] The suspension obtained is then advantageously heated to a temperature of between 40 and 95° C., preferentially between 50 and 70° C., and even more preferably between 55 and 65° C., for a period of between 10 and 180 minutes, preferentially between 20 and 120 minutes, and even more preferably between 40 and 100 minutes. The suspension is then filtered, and the silica-alumina gel obtained contains between 60% and 85% water.

[0109] (Step b)) The silica-alumina gel obtained in step a) is then mixed and kneaded, for example in a Brabender kneader, with a zeolite and optionally a binder, said zeolite having an Acid Site Distribution Index (ASDI) greater than 0.15, to obtain an extrudable paste.

[0110] Said zeolite also has the above mentioned characteristics.

[0111] To adjust the solids content of the paste to be extruded to make it extrudable, mainly solid compounds, preferably oxides or hydrates, may be added. Hydrates will be preferably used, even more preferably aluminium hydrates, which are precursors of aluminate binders.

[0112] In the case where the binder is an aluminate binder, the alumina precursor used in step b) may advantageously be the same or different from the alumina precursor used in step a).

[0113] (Step c)) The shaping step c) may be carried out, for example, by extrusion, pelletizing, the drop congealing (oil drop) method, granulation on a rotating plate or any other method known to the person skilled in the art.

[0114] Preferably, the shaping step c) is carried out by kneading extrusion.

[0115] The extrusion may be carried out by any conventional commercially available tool. The paste obtained from the kneading is extruded through a die, for example using a piston or single or twin screw extruder. This extrusion step may be carried out by any method known to the person skilled in the art.

[0116] Shaping may be carried out in the presence of various components of the catalyst.

[0117] Furthermore, the carriers used according to the invention may be treated with additives, as known to those skilled in the art, to facilitate the shaping of said carriers and / or to improve their final mechanical properties. Mention may be made in particular of the following additives: cellulose, carboxymethylcellulose, carboxyethylcellulose, tall oil, xanthan gum, surfactants, flocculants such as polyacrylamide, carbon black, starch, stearic acid, polyacryl alcohol, polyvinyl alcohol, biopolymers, glucose, polyethylene glycol, etc.

[0118] The support is preferably formed in the form of granules of various shapes and sizes. It is generally used in the form of twisted multilobed or cylindrical extrudates, but may be produced and used in the form of ground powder, spheres, rhomboids, tori, beads or wheels. However, the support is advantageously in the form of extrudates with a diameter of 0.5 to 5 mm, more particularly 0.7 to 3 mm, and even 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 toric. Trilobed and tetralobed forms are preferably used, but any other form may be used.

[0119] (Step d)) The shaped support thus obtained is then dried according to any technique known to those skilled in the art.

[0120] The drying step is carried out at a temperature between 15 and 250°C, preferably between 30 and 200°C, and even more preferably between 50 and 180°C, for a duration typically between 10 minutes and 24 hours. Longer treatment durations are not excluded, but do not contribute to improvements. The drying step is advantageously carried out under an inert or oxygen-containing atmosphere, at atmospheric pressure or at reduced pressure. Preferably, this drying step is carried out in the presence of air at atmospheric pressure.

[0121] (Step e)) The dried support is then subjected to at least one step of heat treatment and / or hydrothermal treatment according to any technique known to those skilled in the art. Hydrothermal treatment is understood to mean contact with water in the vapor or liquid phase. This treatment can be carried out, for example, in a traversing bed, a swept bed or in a static atmosphere. For example, the oven used can be a rotary oven or a vertical oven with radially traversed layers.

[0122] The thermal and / or hydrothermal treatment is carried out at temperatures between 250 and 1100°C, typically for durations between 15 minutes and 10 hours, under an inert or oxygen-containing atmosphere, optionally in the presence of water. Longer treatment durations are not excluded, but do not contribute to improvements. Several combined cycles of thermal or hydrothermal treatments may be carried out.

[0123] According to a preferred embodiment of the invention, the dried material is subjected to at least one hydrothermal treatment in the presence of air and steam at a temperature between 600 and 1100° C., preferably between 650 and 950° C., even more preferably between 750 and 900° C., for a duration between 30 minutes and 5 hours. The steam content is between 20 and 1000 g water per kg of dried air, preferably between 40 and 500 g water per kg of dried air, suitably between 100 and 350 g water per kg of dried air.

[0124] According to another preferred embodiment of the invention, the dried material is subjected to a heat treatment at a temperature between 250 and 700° C., preferably between 300 and 600° C., more preferably between 350 and 550° C., for a duration between 30 min and 5 h, and then the thus heat treated support is subjected to a hydrothermal treatment in the presence of air and steam, at a temperature between 600 and 1100° C., preferably between 650 and 950° C., more preferably between 750 and 900° C., for a duration between 30 min and 5 h. The steam content is between 20 and 1000 g water per kg of dry air, preferably between 40 and 500 g water per kg of dry air, and preferably between 100 and 350 g water per kg of dry air.

[0125] (Step f)) The support obtained in step e) is then subjected to a step f) of introducing onto said support at least one hydrogenation / dehydrogenation element selected from the group formed by the elements from groups VIB and VIII of the periodic table.

[0126] The step of introducing at least one hydrogenation / dehydrogenation element is advantageously carried out by any method known to the person skilled in the art, and in particular by one or more operations of impregnating the support obtained from step e) with a solution containing precursors of elements from groups VIB and / or VIII, optionally precursors of at least one doping element selected from the group formed by phosphorus, boron and silicon, and optionally precursors of at least one element from groups VIIB and / or VB.

[0127] Preferably, said step f) is carried out by dry impregnation with a solution containing precursors of the elements considered.

[0128] According to a first embodiment, said precursors of elements from groups VIB and / or VIII, optional precursors of doping elements and optional precursors of elements from groups VIIB and VB are deposited on said support by one or more co-impregnation steps, i.e. said precursors are introduced simultaneously on said support. The co-impregnation step or steps are preferentially carried out by dry impregnation or impregnation in an excess of solution. If this first embodiment comprises the implementation of several co-impregnation steps, each co-impregnation step is preferably followed by an intermediate drying step, during which the temperature is generally below 200° C., advantageously between 50 and 180° C., preferably between 60 and 150° C. and highly preferably between 75 and 140° C.

[0129] According to a preferred embodiment of the co-impregnation, the impregnation solution is preferably an aqueous solution. Preferably, the aqueous impregnation solution is prepared under pH conditions that promote the formation of heteropolyanions in the solution. For example, the pH of the aqueous impregnation solution is between 1 and 5.

[0130] According to a second embodiment, the precursors of one or more elements from group VIB, one or more elements from group VIII, optionally one or more doping elements and optionally one or more elements from groups VIIB and VB are introduced onto the support resulting from step e) by successive depositions in any order. The depositions may be carried out by dry impregnation, excess impregnation or else deposition / precipitation according to methods well known to those skilled in the art. In this second embodiment, an intermediate drying step may be carried out between two successive impregnations, generally at a temperature below 200° C., advantageously between 50 and 180° C., preferably between 60 and 150° C. and highly preferably between 75 and 140° C.

[0131] Regardless of the mode of deposition of the precursor, the solvent used in the composition of the impregnation solution is selected to dissolve the precursor, and may be, for example, water or an organic solvent (eg, an alcohol).

[0132] In a third embodiment, a solution of precursors of one or more metals selected from an element from group VIB, an element from group VIII, optionally phosphorus and optionally one or more elements from groups VIIB and VB is added during step b). The co-kneading is advantageously carried out in a kneader, for example a "Brabender" type kneader well known to those skilled in the art.

[0133] Precursors of elements from group VIB that may be used are well known to those skilled in the art.

[0134] Use may be made, by way of example, of molybdenum sources, of oxides and hydroxides, molybdic acid and its salts, in particular the ammonium salts, such as ammonium molybdate, ammonium heptamolybdate, phosphomolybdic acid (H 3 PMo 12 O 40 ) and its salts, and optionally silicomolybdic acid (H 4 SiMo 12 O 40) and its salts. The source of molybdenum can also be any heteropoly compound, for example of the Keggin, defect Keggin, substituted Keggin, Dawson, Anderson or Strandberg type. Preference is given to using molybdenum trioxide and heteropoly compounds of the Keggin, defect Keggin, substituted Keggin and Strandberg types.

[0135] For example, use may be made of, among the sources of tungsten, oxides and hydroxides, tungstic acid and its salts, in particular the ammonium salts, such as ammonium tungstate, ammonium metatungstate, phosphotungstic acid and its salts, and optionally silicotungstic acid (H 4 SiW 12 O 40 ) and its salts. The source of tungsten can also be any heteropoly compound, for example of the Keggin, defective Keggin, substituted Keggin or Dawson type. Use is preferably made of oxides and ammonium salts, for example ammonium metatungstate, or heteropoly compounds of the Keggin, defective Keggin or substituted Keggin type.

[0136] The precursors of elements from group VIII that may be used are also known to those skilled in the art. They are advantageously selected from the oxides, hydroxides, hydroxycarbonates, carbonates, carboxylates (such as acetates), nitrates, sulfates, phosphates and halides (such as chlorides, bromides and fluorides) of elements from group VIII. For example, nickel hydroxide, nickel hydroxycarbonate or nickel nitrate, cobalt carbonate or cobalt hydroxide are preferably used.

[0137] In the case where a doping element selected from phosphorus, boron or silicon is present, the preferred source of phosphorus is orthophosphoric acid H 3 PO 4However, its salts and esters, for example 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. Phosphorus may also be introduced simultaneously with one or more elements from group VIB in the form of heteropolyanions of the Keggin, defect-Keggin, substituted-Keggin or Strandberg type, for example tungstophosphoric acid.

[0138] The phosphorus content is adjusted to form mixed compounds in the solution and / or on the support, such as tungsten-phosphorus or molybdenum-phosphorus or molybdenum-tungsten-phosphorus, without this limiting the scope of the invention. These mixed compounds may be heteropolyanions, such as Anderson's heteropolyanions.

[0139] The source of boron is boric acid, preferably H orthoborate. 3 BO 3 , ammonium diborate or ammonium pentaborate, boron oxide or boric acid esters. The boron may 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. The boron may be introduced, for example, by a solution of boric acid in a water / alcohol mixture.

[0140] 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 (NH 4 ) 2 SiF 6 or sodium fluorosilicate 2 SiF 6Silicomolybdic acid and its salts, silicotungstic acid and its salts may be advantageously used. Silicon may be added, for example, by impregnation with ethyl silicate in solution in a water / alcohol mixture. Silicon may be added, for example, by impregnation with silicon compounds of the silicone or silicic acid type suspended in water.

[0141] In the case where the catalyst according to the invention also contains at least one element from group VB, the sources of elements from group VB that may 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 niobium pentoxide (Nb 2 O 5 , Niobate 2 O 5 H 2 O, niobium hydroxide and polyoxyniobate, formula Nb(OR1) 3 (wherein R1 is an alkyl group), niobium alkoxide, niobium oxalate NbO(HC 2 O 4 ) 5 or ammonium niobate. Preferably used are niobium oxalate or ammonium niobate.

[0142] In the case where the catalyst according to the invention also comprises at least one element from group VIIB, the sources of elements from group VIIB that may be used are well known to those skilled in the art.Preference is given to using the ammonium, nitrate and chloride salts.

[0143] (Step g)) The impregnated support obtained from step f) is then subjected to a drying step.

[0144] Preferably, said drying step is carried out at a temperature advantageously below 250° C., preferably between 15 and 250° C., more preferentially between 30 and 220° C., even more preferentially between 50 and 200° C., even more preferentially between 70 and 180° C., typically for a duration between 10 minutes and 24 hours. Longer durations are not excluded, but do not necessarily contribute to improvements.

[0145] The drying step may be carried out by any technique known to the person skilled in the art. It is advantageously carried out under an inert atmosphere or under an oxygen-containing atmosphere or under a mixture of an inert gas and oxygen. It is advantageously carried out at atmospheric pressure or at reduced pressure. Preferably, this step is carried out at atmospheric pressure in the presence of air or nitrogen.

[0146] (Step h) (optional) The impregnated and dried support obtained from step g) is then optionally subjected to a step of thermal and / or hydrothermal treatment, according to any technique known to the person skilled in the art, to obtain said catalyst according to the invention. This treatment may be carried out, for example, in a traversing bed, a swept bed or in a static atmosphere. For example, the oven used may be a rotary oven or a vertical oven with radially traversed layers.

[0147] The thermal and / or hydrothermal treatment is advantageously carried out at temperatures between 250°C and 1000°C, preferably between 300°C and 600°C, under an inert or oxygen-containing atmosphere, optionally in the presence of steam. The duration of this thermal treatment is generally between 15 minutes and 10 hours. Longer durations are not excluded, but do not necessarily contribute to improvements. The steam content is advantageously between 0 and 100 g water per kg of dry air, preferably between 0 and 80 g water per kg of dry air.

[0148] The catalyst according to the invention thus obtained is preferably subjected to a sulfurization treatment for its use in the hydrocracking process according to the invention, making it possible to at least partially convert the metal species into sulfides before contacting with the feedstock to be treated. The elements from groups VIB and VIII of the catalyst according to the invention may be present completely or partially in the form of metals and / or oxides and / or sulfides.

[0149] 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 known to those skilled in the art and already described in the literature.

[0150] The sulfurizing agent is H 2 S gas or any other sulfur-containing compound used for the activation of the hydrocarbon feedstock with the aim of sulfurizing the catalyst. Said sulfur-containing compound is advantageously chosen from alkyl disulfides, such as dimethyl disulfide (DMDS), alkyl sulfides, such as dimethyl sulfide, n-butyl thiol, polysulfide compounds of the tert-nonyl polysulfide type, such as TPS-37 or TPS-54 sold by Arkema, or any other compound known to the skilled person to obtain good sulfurization of the catalyst. Preferably, the catalyst is sulfurized in situ in the presence of a sulfurizing agent and a hydrocarbon feedstock. Highly preferably, the catalyst is sulfurized in situ in the presence of a hydrocarbon feedstock with the addition of dimethyl disulfide, at a temperature between 150 and 800°C, preferably between 250 and 600°C.

[0151] The present invention also relates to a process for hydrocracking and / or hydroconversion of a hydrocarbon feedstock using said catalyst according to the invention.

[0152] (hydrocracking method) Another subject of the invention likewise has the subject of a method for hydrocracking at least one hydrocarbon feedstock in the presence of the catalyst of the invention, the hydrocarbon feedstock being preferably in liquid form, at least 50% by weight of the compounds of which have a boiling point above 300° C. and below 650° C., the temperature during hydrocracking being between 200° C. and 480° C., the total pressure being between 1 MPa and 25 MPa, the ratio of the volume of hydrogen per volume of hydrocarbon feedstock being 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 (preferably in liquid form) per volume of catalyst packed in the reactor, being between 0.1 and 50 h . -1 It is.

[0153] Preferably, the hydrocracking process according to the invention is carried out in the presence of hydrogen, at a temperature of 250-480° C., preferably 320-450° C., highly preferably 330-435° C., at a pressure of 2-25 MPa, preferably 3-20 MPa, and at a space velocity of 0.1-20 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 3000 NL / L.

[0154] Even more preferably, the hydrocracking process according to the invention is carried out in the presence of hydrogen, where the temperature is between 300 and 400° C., the pressure is between 9 and 20 MPa and the space velocity is between 0.2 and 3 h . -1 The amount of hydrogen introduced is set so that the volume ratio of hydrogen volume (liters) / hydrocarbon volume (liters) is 100 to 2000 NL / L.

[0155] 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, which make 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.) can be varied in a wide variety according to the knowledge of the person skilled in the art.

[0156] (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, the boiling point of at least 50% by weight of the compounds of which is greater than 300° C. and less than 650° C., preferably at least 60% by weight, suitably at least 75% by weight, more preferably at least 80% by weight of the compounds of which is greater than 300° C. and less than 650° C.

[0157] The feedstock is advantageously chosen from LCO (Light Cycle Oil, light gas oil obtained from a catalytic cracking unit), atmospheric distillates, vacuum distillates, for example gas oils obtained from the 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 obtained from the solvent dewaxing of lubricant base stocks, distillates originating from processes for the fixed or ebullated bed desulfurization or hydroconversion of AR (atmospheric residues) and / or VR (vacuum residues) and / or deasphalted oils, and paraffins obtained from a Fischer-Tropsch process, or else any mixture of the abovementioned feedstocks. Mention may be made of feedstocks of renewable origin (e.g. vegetable oils, animal fats, oils from hydrothermal conversion or pyrolysis of lignocellulosic biomass), and also plastic pyrolysis oils, as well as these feedstocks on their own or in any mixture with the abovementioned hydrocarbon feedstocks. The above list is not limiting. The feedstock preferably has 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, suitably greater than 340°C.

[0158] 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 5000 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.

[0159] The feedstock may optionally contain metals. The combined nickel and vanadium content of the feedstock treated in the process according to the invention is preferably less than 10 ppm by weight, suitably less than 5 ppm by weight, even more preferably less than 1 ppm by weight.

[0160] The feedstock may optionally contain asphaltenes, which generally have an asphaltene content of less than 3000 ppm by weight, preferably less than 1000 ppm by weight, and even more preferably less than 200 ppm by weight.

[0161] Advantageously, when the catalyst according to the invention is used after the hydrotreating section, the nitrogen, sulfur, metal and / or asphaltene content in the liquid injected into the process according to the invention using the catalyst according to the invention is reduced. Advantageously, 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, more preferably between 0 and 30 ppm. The sulfur content is preferably less than 1000 ppm, preferably between 5 and 500 ppm, more preferably between 10 and 400 ppm. The asphaltene content is preferably less than 200 ppm, while the metal (Ni or V) content is less than 1 ppm.

[0162] The hydrocracking process according to the invention may include a fractionation step between the section for hydrotreating the feedstock and the hydrocracking reactor(s) using the catalyst according to the invention. In one embodiment where the hydrocracking process is carried out without (gas and liquid) fractionation between the hydrotreating section and the hydrocracking reactor(s) using the catalyst according to the invention (a "one-step" process), the nitrogen and sulfur removed from the liquid by hydrotreating are expressed as NH 3 and H 2In the preferred case where the hydrocracking process is carried out with (gas and liquid) fractionation between the hydrotreating section and at least one hydrocracking reactor using the catalyst according to the invention ("two-step" process), the NH 3 The content is 0 to 100 ppm, preferably 0 to 50 ppm, and even more preferably 0 to 20 ppm. 2 The S content is from 0 to 1000 ppm, preferably from 5 to 500 ppm, and even more preferably from 10 to 400 ppm.

[0163] The process can be carried out in one or two steps, as described below, depending on the targeted degree of feed conversion, with or without recycling of the unconverted fraction. Preferably, the process is carried out in two steps, with recycling of the unconverted fraction. The catalyst according to the invention can be used, without limitation, alone or in combination with another hydrocracking catalyst, in at least one hydrocracking reactor of one or two stages of the hydrocracking process. Preferably, the catalyst according to the invention is used in at least one hydrocracking reactor located downstream of the (gas and liquid) fractionation.

[0164] The operating conditions used in the process according to the invention generally make it possible to obtain a conversion per pass to products having a boiling point below 340° C., better still below 370° C.: more than 15% by weight, and even more preferably between 20 and 100% by weight.

[0165] In the "one-step" process, the feedstock to be converted is passed once over the hydrocracking catalyst. The resulting product is added directly to the refinery's gasoline, kerosene or diesel pool, and the unconverted fraction can serve as a base for oil or can be converted by the FCC process.

[0166] In the "two-step" process, an intermediate separation is carried out at the outlet from the first hydrocracking reactor, making it possible to separate the cracked products from the part not converted in the first reactor. The unconverted fraction of the feedstock is then sent to a second hydrocracking reactor containing a second hydrocracking catalyst, in order to increase the overall conversion of the feedstock to middle distillates.

[0167] The following examples are illustrative of the present invention but are not intended to limit the scope of the invention.

[0168] (Example) Example 1: Preparation of catalyst C1 (according to the invention) (Preparation of Silica-Alumina Gel SA1) The preparation of boehmite gel G1 is carried out according to example 1 of patent US 4,154,812 and spray dried. The obtained boehmite gel G1 has the following characteristics:

[0169] [Table 1]

[0170] 126 g of this boehmite gel are dispersed in 1450 g of water acidified with 3.9 g of 68% nitric acid. The resulting suspension is stirred at ambient temperature using a mechanical stirrer. The preparation of 1 liter of silicic acid sol is carried out by adding SiO 2 This is done by diluting the sodium silicate solution to the concentration required to obtain an equivalent amount of 60 g and passing it through an ion exchange resin (previously acidified). The obtained silica sol is added to the boehmite suspension with a flow rate of 22 mL / min using a peristaltic pump. The mixture is then heated to 60° C. and then aged at this temperature with stirring for 1 hour. The suspension is then filtered on a sintered Buchner-type device to obtain the silica-alumina gel SA1.

[0171] The silica content indicated by X-ray fluorescence measurement on silica-alumina gel SA1 is the total oxide content (SiO 2 +Al 2 O3 ) relative to SiO 2 Expressed in weight percent, it is 32.2% by weight.

[0172] The loss on ignition of this gel SA1 is 70.8%.

[0173] The loss on ignition corresponds to the moisture content of the material; it is measured via the loss of mass after heat treatment at 1000° C. for 4 hours.

[0174] (Zeolite Z1) A USY type zeolite Z1 is used, which has the following characteristics:

[0175] [Table 2]

[0176] (Forming of carrier S1) 218 g of silica-alumina gel SA1, 4 g of zeolite Z1 and 11.7 g of boehmite gel G1 are mixed and kneaded in a Z-arm kneader at 50 rpm, then the paste obtained is extruded through a three-lobed die with a diameter of 2.5 mm. The amount of zeolite Z1 added corresponds to a mass content of 5% by weight, the weight of Z1 relative to the total weight of the dry support.

[0177] (Hydrothermal treatment of carrier S1) After drying at 80° C. for 20 hours in a ventilated oven, the extrudates are hydrothermally treated at 450° C. for 2 hours under a stream of air containing less than 40 g of water per kilogram of dry air, then at 800° C. for 2 hours in the presence of steam containing 200 g of water per kilogram of dry air.

[0178] The characteristics of the carrier S1 thus obtained are summarized in Table 7 below.

[0179] Preparation of Catalyst C1 (According to the Invention) The catalyst C1 is obtained by dry impregnation of the support S1 with an aqueous solution containing tungsten and nickel salts. The tungsten salt is ammonium metatungstate (NH 4 ) 6 H 2 W 12 O 40 4H 2 O, and the nickel salt is nickel nitrate Ni(NO 3 ) 2 6H 2 After aging for 10 hours at ambient temperature in a water-saturated atmosphere, the impregnated extrudates are dried in a ventilated oven at 120° C. for 18 hours and then hydrothermally treated at 500° C. for 2 hours under a stream of air containing less than 40 g of water per kilogram of dry air by weight.

[0180] The characteristics of the catalyst C1 thus obtained are summarized in Table 8 below.

[0181] Example 2: Preparation of Catalyst C2 (Comparative Example) The adjustment of the support S2 of the catalyst C2 not in accordance with the invention is carried out using the commercially available PURAL® SB3 boehmite gel having the following characteristics:

[0182] [Table 3]

[0183] 115 g of commercial PURAL® SB3 boehmite gel are dispersed in 1450 g of water acidified with 3.9 g of 68% nitric acid. The resulting suspension is stirred at ambient temperature using a mechanical stirrer. The preparation of 1 liter of silicic acid sol is carried out by dispersing SiO in the sol. 2This is done by diluting the sodium silicate solution to the concentration required to obtain an equivalent amount of 60 g and passing it through an ion exchange resin (previously acidified). The obtained silica sol is added to the boehmite suspension with a flow rate of 22 mL / min using a peristaltic pump. The mixture is then heated to 60° C. and then aged at this temperature with stirring for 1 hour. The suspension is then filtered on a sintered Buchner-type device to obtain the silica-alumina gel SA2.

[0184] The silica content indicated by X-ray fluorescence measurement on silica-alumina gel SA2 is the total oxide content (SiO 2 +Al 2 O 3 ) relative to SiO 2 Expressed in weight percent, it is 32.0% by weight.

[0185] The loss on ignition of Gel SA2 is 74.5%.

[0186] (Forming of carrier S2) 247 g of silica-alumina gel SA2, 4 g of the zeolite Z1 used above and 11.6 g of boehmite are then kneaded in a Z-arm kneader at 50 rpm, and the paste obtained is then extruded through a three-lobed die with a diameter of 2.5 mm. The amount of zeolite Z1 added corresponds to a mass content of 5% by weight of Z1 relative to the total weight of the dry carrier.

[0187] (Hydrothermal treatment of carrier S2) After drying at 80° C. for 20 hours in a ventilated oven, the extrudates are hydrothermally treated at 450° C. for 2 hours under a stream of air containing less than 40 g of water per kilogram of dry air, then at 800° C. for 2 hours in the presence of steam containing 200 g of water per kilogram of dry air.

[0188] The characteristics of the carrier S2 thus obtained are summarized in Table 7 below.

[0189] (Preparation of Catalyst C2 (Comparative Example)) Catalyst C2 is obtained by dry impregnation of support S2 according to the same protocol as described for the preparation of catalyst C1. The physicochemical characteristics of catalyst C2 thus obtained are summarized in Table 8 below.

[0190] Example 3: Preparation and molding of catalyst C3 (comparative example) (Preparation of Silica-Alumina Gel SA3) The preparation of boehmite gel G3 is carried out according to example 1 of patent US6589908 and spray dried. The obtained boehmite gel G3 has the following characteristics:

[0191] [Table 4]

[0192] 119 g of this boehmite gel are dispersed in 1450 g of water acidified with 3.9 g of 68% nitric acid. The resulting suspension is stirred at ambient temperature using a mechanical stirrer. The preparation of 1 liter of silicic acid sol is carried out by adding SiO 2 This is done by diluting the sodium silicate solution to the concentration required to obtain an equivalent amount of 60 g and passing it through an ion exchange resin (previously acidified). The obtained silica sol is added to the boehmite suspension with a flow rate of 22 mL / min using a peristaltic pump. The mixture is then heated to 60° C. and then aged at this temperature with stirring for 1 hour. The suspension is then filtered on a sintered Buchner-type device to obtain the silica-alumina gel SA3.

[0193] The silica content indicated by X-ray fluorescence measurement on silica-alumina gel SA3 is the total oxide content (SiO 2 +Al 2 O 3 ) relative to SiO 2 Expressed in weight percent, it is 33.2% by weight.

[0194] The loss on ignition of SA3 is 72%.

[0195] (Forming of carrier S3) 226 g of silica-alumina gel SA3, 4 g of zeolite Z1 used above and 11.7 g of boehmite are then kneaded in a Z-arm kneader at 50 rpm, then the paste obtained is extruded through a three-lobed die with a diameter of 2.5 mm. The amount of zeolite Z1 added corresponds to a mass content of 5% by weight of Z1 relative to the total weight of the dry carrier.

[0196] (Hydrothermal treatment of carrier S3) After drying at 80° C. for 20 hours in a ventilated oven, the extrudates are hydrothermally treated at 450° C. for 2 hours under a stream of air containing less than 40 g of water per kilogram of dry air, then at 800° C. for 2 hours in the presence of steam containing 200 g of water per kilogram of dry air.

[0197] The characteristics of the carrier S3 thus obtained are summarized in Table 7 below.

[0198] (Preparation of Catalyst C3 (Comparative Example)) Catalyst C3 is obtained by dry impregnation of support S3 following the same protocol as described for the preparation of catalyst C1. The physicochemical characteristics of catalyst C3 thus obtained are summarized in Table 8 below.

[0199] Example 4: Preparation and molding of catalyst C4 (comparative example) The boehmite gel G1 described in Example 1 was heated in an autoclave at 110° C. for 1 hour to give, after filtration, a gel G4 having different characteristics from the gel G1, which are given below.

[0200] [Table 5]

[0201] 369 g of boehmite gel G4 are dispersed in 1200 g of water acidified with 3.9 g of 68% nitric acid. The resulting suspension is stirred at ambient temperature using a mechanical stirrer. 1 liter of silicic acid sol is prepared by dispersing SiO2 This is done by diluting the sodium silicate solution to the concentration required to obtain an equivalent amount of 60 g and passing it through an ion exchange resin (previously acidified). The obtained silica sol is added to the boehmite suspension with a flow rate of 22 mL / min using a peristaltic pump. The mixture is then heated to 60° C. and then aged at this temperature with stirring for 1 hour. The suspension is then filtered on a sintered Buchner-type device to obtain silica-alumina gel SA4.

[0202] The silica content indicated by X-ray fluorescence measurements on silica-alumina gel SA4 is the total oxide content (SiO 2 +Al 2 O 3 ) relative to SiO 2 Expressed in weight percent, it is 32.8% by weight.

[0203] (Forming of carrier S4) 264 g of silica-alumina gel SA4 (LOI=73.8%), 4 g of the zeolite Z1 used above and 11.6 g of boehmite are mixed and kneaded in a Z-arm kneader at 50 rpm, then the paste obtained is extruded through a three-lobe die with a diameter of 2.5 mm. The amount of zeolite Z1 added corresponds to a mass content of 5% by weight of Z1 relative to the total weight of the dry carrier.

[0204] (Hydrothermal treatment of carrier S4) After drying at 80° C. for 20 hours in a ventilated oven, the extrudates are hydrothermally treated at 450° C. for 2 hours under a stream of air containing less than 40 g of water per kilogram of dry air, then at 800° C. for 2 hours in the presence of steam containing 200 g of water per kilogram of dry air.

[0205] The characteristics of the carrier S4 thus obtained are summarized in Table 7 below.

[0206] (Preparation of Catalyst C4 (Comparative Example)) Catalyst C4 is obtained by dry impregnation of support S4 following the same protocol as described for the preparation of catalyst C1. The physicochemical characteristics of catalyst C4 thus obtained are summarized in Table 8 below.

[0207] Example 5: Preparation and molding of catalyst C5 (Zeolite Z5) Zeolite Z5 of the USY type was used, which has the following characteristics:

[0208] [Table 6]

[0209] (Forming of carrier S5) 207 g of the silica-alumina gel SA1 used in Example 1, 3.9 g of zeolite Z5 and 11.7 g of boehmite are then kneaded in a Z-arm kneader at 50 rpm, and the paste obtained is then extruded through a three-lobed die with a diameter of 2.5 mm. The amount of zeolite Z5 added corresponds to a mass content of 5% by weight of Z5 relative to the total weight of the dry carrier.

[0210] (Hydrothermal treatment of carrier S5) After drying at 80° C. for 20 hours in a ventilated oven, the extrudates are hydrothermally treated at 450° C. for 2 hours under a stream of air containing less than 40 g of water per kilogram of dry air, then at 800° C. for 2 hours in the presence of steam containing 200 g of water per kilogram of dry air.

[0211] The characteristics of the carrier S5 thus obtained are summarized in Table 7 below.

[0212] (Preparation of Catalyst C5 (Comparative Example)) Catalyst C5 is obtained by dry impregnation of support S5 following the same protocol as described for the preparation of catalyst C1. The physicochemical characteristics of catalyst C5 thus obtained are summarized in Table 8 below.

[0213] The characteristics of the different supports S1-S5 and the different catalysts C1-C5 are listed in the table below.

[0214] [Table 7]

[0215] [Table 8]

[0216] (Example 6: Evaluation of catalysts C1 to C5 in one-step hydrocracking of vacuum distillate) Catalysts C1 to C5, the preparation of which is described in Examples 1 to 5, are used to carry out hydrocracking of previously hydrotreated vacuum distillates, the main characteristics of which are given below.

[0217] [Table 9]

[0218] Catalysts C1-C5 are used according to the method of the present invention by using an isothermal test pilot unit containing a fixed bed reactor with upward flow of the feedstock. Dimethyl disulfide (DMDS) and aniline are added to the test feedstock, respectively, to obtain 2.8 wt.% sulfur and 1250 wt. ppm nitrogen in the added feedstock, simulating the partial pressures of hydrogen sulfide and ammonia generated by the hydrotreating step of the method.

[0219] Each catalyst was evaluated separately and prior to hydrocracking tests, it was sulfurized with straight-run gas oil containing 4 wt.% dimethyl disulfide (DMDS) and 2 wt.% aniline. The HSV (HSV = hourly space velocity) during sulfurization was 2h -1 and H 2 The volume ratio of the feedstock is 1000NL / L, the total pressure is 14MPa, the temperature is 350°C, for 6 hours.

[0220] After sulfurization, the operating conditions are adjusted to those used in the hydrocracking test: HSV: 1.5 h -1 , H 2 / Feed volume ratio: 1000 NL / L, total pressure: 14 MPa. The reactor temperature is adjusted to target a net conversion of 70 wt.% of the 370°C+ fraction after 150 hours with the feed.

[0221] The performance quality of the catalyst is expressed by the net conversion to products with boiling points below 370°C (NC_370-) and the total selectivity for middle distillates (150-370°C fraction) (GS_MD), which are expressed based on the simulated distillation results.

[0222] The net conversion NC to products boiling below 370° C. (NC_370−) is defined by: NC_370-=[(%370-Effluent)-(%370--Feedstock)] / [100-(%370--Feedstock)] where %370_effluent is the mass content of compounds in the effluent having a boiling point below 370° C. %370-Feed is the mass content of compounds in the feed that have a boiling point below 370°C.

[0223] The total selectivity for middle distillates (GS_MD) is defined by: GS_MD=(%150-370 effluent) / (%370-effluent) In the formula, %150-370 effluent is the mass content of compounds in the effluent having a boiling point between 150°C and 370°C.

[0224] The catalyst performance qualities obtained are given in Table 10 below.

[0225] [Table 10]

[0226] Example 6 therefore shows the overall advantage of using catalyst C1 according to the invention for hydrocracking of hydrocarbon feedstocks, in particular by making it possible to obtain a net conversion (NC_370): 70% to products with a boiling point below 370°C at a lower temperature than catalysts C2, C3, C4 and C5, while maintaining a high overall selectivity for middle distillates (GS_MD).

Claims

1. Catalyst comprising at least one hydrogenation / dehydrogenation element selected alone or in a mixture from the group formed by elements from groups VIB and VIII of the periodic table, and a support comprising at least one zeolite and at least one amorphous silica-alumina, said support being as follows: the pore volume expressed in pores with a diameter between 6 nm and 11 nm is less than 0.5 mL / g, as measured by nitrogen porosimetry; - the granular density is greater than 0.93 g / mL, measured by mercury displacement under a pressure of 0.003 MPa; - Tapped packing density (TPD) is greater than 0.5 g / mL and less than 0.65 g / mL.

2. Catalyst according to claim 1, wherein the content in the catalyst of elements from group VIII is from 0.03% to 15% by weight of oxide relative to the total weight of the catalyst, preferably from 0.5% to 10% by weight of oxide, highly preferably from 1.0% to 8% by weight of oxide, and the content in the catalyst of elements from group VIB is from 1% to 50% by weight of oxide relative to the total weight of the catalyst, preferably from 5% to 40% by weight of oxide, even more preferably from 10% to 35% by weight of oxide.

3. Catalyst according to claim 1, wherein the element from group VIII is nickel and the element from group VIB is tungsten.

4. 2. The catalyst of claim 1, wherein the zeolite is selected from Y, USY, VUSY, SDUSY, mordenite, beta, EU-1, EU-2, EU-11, Nu-87, ZSM-48 or ZBM-30 zeolites.

5. 5. The catalyst of claim 4, wherein the zeolite is selected from Y, ultrastable Y (USY), highly ultrastable Y (VUSY) or dealuminated ultrastable Y (SDUSY) zeolites.

6. 10. The catalyst of claim 1, wherein the zeolite has an acid site distribution index (ASDI) greater than 0.15, as determined by H / D exchange.

7. Catalyst according to claim 1, wherein the volume expressed in pores of the zeolite with a diameter of more than 50 nm accounts for less than 15%, preferably less than 10%, of the total pore volume, as measured by nitrogen physisorption.

8. Catalyst according to claim 1, wherein the pore volume contained in pores with a diameter of more than 6 nm and less than 11 nm of the support is between 0.05 and 0.45 mL / g, preferably between 0.1 and 0.35 mL / g, as measured by nitrogen physisorption.

9. Catalyst according to claim 1, wherein the support also comprises a binder, said binder consisting of at least one refractory oxide selected alone or in mixture from the group formed by alumina, silica-alumina, clay, titanium oxide, boron oxide and zirconia, preferably the binder is alumina.

10. Catalyst according to claim 1, wherein the weight content of silica-alumina in the catalyst is generally between 1% and 99% by weight, advantageously between 10% and 85% by weight, preferably between 40% and 75% by weight, relative to the total weight of said catalyst.

11. Catalyst according to claim 1, wherein the weight content of zeolite in the catalyst is generally between 0.1% and 30% by weight, advantageously between 0.2% and 20% by weight, preferably between 0.5% and 10% by weight, more preferably between 1% and 9% by weight and even more preferably between 1.5% and 8% by weight relative to the total weight of said catalyst.

12. A method for preparing the catalyst according to any one of claims 1 to 11, comprising at least the following steps: a) preparing a silica-alumina gel by mixing a silica precursor with an alumina precursor; said alumina precursor having: ・Dispersibility index: 15% to 70%, sodium content: from 0.003% to 2% by weight relative to the total mass of the alumina precursor; sulfur content: from 0.005% to 2% by weight relative to the total mass of the alumina precursor; b) mixing at least one zeolite with the silica-alumina gel obtained from step a); the zeolite has an acid site distribution index (ASDI) greater than 0.15, as measured by H / D exchange; c) shaping the resulting mixture, optionally in the presence of an aluminate binder; d) at least one step of drying the shaped material; e) at least one step of thermal and / or hydrothermal treatment of the dried material; obtaining a support; f) introducing onto the support at least one hydrogenation / dehydrogenation element selected from the group formed by elements from group VIB of the periodic table and non-noble metal elements from group VIII of the periodic table; g) at least one step of drying the impregnated support; and e) optionally at least one step of thermal and / or hydrothermal treatment of the impregnated and dried support; to obtain said catalyst.

13. A process for hydrocracking at least one hydrocarbon feedstock, the hydrocarbon feedstock preferably being in liquid form, at least 50% by weight of the compounds of the hydrocarbon feedstock having a boiling point above 300°C and below 650°C, the hydrocracking being carried out in the presence of a catalyst according to any one of claims 1 to 11 or a catalyst prepared according to the preparation process according to claim 12, 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 per 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, preferably in liquid form, per volume of catalyst charged in the reactor, is between 0.1 and 50 h －１ That's the method.