A hydrocracking catalyst for the production of naphtha comprising a zeolite Y having a lattice parameter strictly greater than 24.50 angstroms and a beta zeolite, and having a Y / beta ratio of 5 to 12.

Abstract

The present invention describes a selective hydrocracking catalyst for naphtha fractions and further describes a hydrocracking process using said catalyst. The catalyst comprises at least one hydrodehydrogenating element selected from the group consisting of Group VIB and non-noble Group VIII elements of the Periodic Table, utilized alone or as a mixture, and a support comprising at least one porous mineral matrix, a gamma zeolite having a primary crystal lattice parameter a0 strictly greater than 24.42 Å, and a beta zeolite, the weight ratio of said gamma zeolite to said beta zeolite in the catalyst being 5-12.

Description

[Technical field]

[0001] The present invention relates to a hydrocracking catalyst based on zeolite Y and zeolite beta and also to its use for the production of naphtha by hydrocracking of petroleum fractions of the vacuum distillate and gas oil type. This type of process is used in schemes intended, inter alia, for the conversion of hydrocarbon feedstocks for the production of petrochemical intermediates and gasoline fuels. [Background technology]

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

[0003] Hydrocracking catalysts are also classified by the primary products obtained when they are used in a hydrocracking process; the two primary products are middle distillates and naphtha.

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

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

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

[0007] It is known to use catalysts based on FAU type zeolites for producing naphtha fractions.

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

[0009] Other catalysts based on zeolite Y and zeolite beta may also be used.

[0010] UOP describes hydrocracking catalysts containing zeolite beta and zeolite Y, the lattice constant of zeolite Y being 24.38-24.50 angstroms (Å), the catalysts being characterized by a Y / beta weight ratio of 5-12. The catalysts have a relatively large proportion of zeolite Y compared to the proportion of zeolite beta. These catalysts have been demonstrated to have improved selectivity and activity compared to conventional commercial catalysts. Also disclosed is a hydrocracking process using said catalysts at high temperatures and pressures to convert a hydrocarbon feedstock into products having lower boiling points and lower molecular weights. In particular, the resulting products contain a high proportion of components boiling within the naphtha fraction temperature range (C6-216°C).

[0011] In an attempt to develop a new hydrocracking catalyst selective for naphtha fractions, the Applicant has surprisingly discovered that it is possible to combine at least one hydrogenation-dehydrogenation element selected from the group formed by the elements of group VIB and the non-noble metal elements of group VIII of the periodic table, and at least one porous mineral matrix, the unit cell of which has an initial lattice constant a0 It has been found that a catalyst comprising a zeolite Y having a molecular weight distribution strictly greater than 24.50 Å and a support comprising zeolite beta, the weight ratio of said zeolite Y to said zeolite beta being between 5 and 12, makes it possible to obtain an improved selectivity towards naphtha fractions, in particular compared to prior art catalysts. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] U.S. Patent No. 7,611,689 [Patent Document 2] U.S. Patent No. 7,510,645 Summary of the Invention [Means for solving the problem]

[0013] (Subject of the Invention) More specifically, the present invention relates to a method for producing a porous mineral matrix comprising at least one hydrogenation-dehydrogenation element, selected alone or in a mixture from the group formed by the elements of group VIB and the non-noble metal elements of group VIII of the periodic table, and at least one porous mineral matrix having an initial lattice constant a of the unit cell. 0 and a support comprising zeolite beta, wherein the weight ratio of said zeolite Y to said zeolite beta in the catalyst is 5-12.

[0014] The invention advantageously comprises at least one hydrodehydrogenating element, used alone or in a mixture, selected from the group formed by the elements of group VIB and the non-noble metal elements of group VIII of the periodic table, and at least one porous mineral matrix, the unit cell of which has an initial lattice constant a 0 and a support comprising zeolite beta, wherein the weight ratio of said zeolite Y to said zeolite beta in the catalyst is 5-12.

[0015] The invention advantageously comprises at least one hydrodehydrogenating element selected from the group formed by the elements of group VIB and the non-noble metal elements of group VIII of the periodic table, used alone or in a mixture, and at least one porous mineral matrix, the unit cell of which has an initial lattice constant a 0 and a support comprising zeolite beta, wherein the weight ratio of said zeolite Y to said zeolite beta in the catalyst is 5-12.

[0016] This weight ratio is calculated from the dry mass of the zeolites, ie the mass of the zeolites (dry mass) corrected for their water content, determined by measuring the loss on ignition at 1000°C.

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

[0018] One advantage of the present invention is to provide hydrocracking catalysts for obtaining improved activity towards naphtha fractions when used in the hydrocracking process according to the present invention, compared to prior art catalysts, while maintaining selectivity towards naphtha fractions compatible with that obtained with prior art catalysts.

[0019] In the present invention, the conversion activity of a hydrocracking catalyst for naphtha production is determined by comparing the temperature at which the catalyst must be used to produce at least 65% by weight of products with a boiling point below 216° C. during catalytic testing. The lower the desired temperature, the more active the catalyst is. This reduction in temperature makes it possible, for example, to limit the energy consumption of the process and to increase the cycle time for using the catalyst, as well as to process less reactive feedstocks without modifying the capacity or scheme of the process.

[0020] In the present invention, the selectivity of the hydrocracking catalyst for naphtha production is determined during the catalytic test and corresponds to the proportion as a weight percentage relative to the total mass of products leaving the processing of the range of naphtha cuts, i.e. products boiling between the boiling temperature of hydrocarbon compounds containing 6 carbon atoms per molecule (i.e. 68°C boiling point) and 216°C.

[0021] For the purposes of the present invention, the various embodiments presented may be used alone or in combination with one another, without any limitations on said combinations.

[0022] For purposes of the present invention, various ranges of parameters for a given process, such as pressure ranges and temperature ranges, may be used alone or in combination. For example, for purposes of the present invention, a preferred range of pressure values ​​may be combined with a more preferred range of temperature values.

[0023] In the following text, the groups of chemical elements are given according to the CAS classification (CRC Handbook of Chemistry and Physics, published by CRC Press, editor DR Lide, 81st edition, 2000-2001). For example, group VIII according to the CAS classification corresponds to metals from columns 8, 9 and 10 according to the new IUPAC classification, and group VIB corresponds to metals from column 6.

[0024] In the text that follows, the expressions "of between A and B" and "between A and B" are equivalent and mean that both limits of the interval (A, B) are included in the stated range of both values. If this is not the case and if both limits are not included in the stated range, such an explanation is provided by the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Detailed Description of the Invention (hydrogenation / dehydrogenation function) According to the invention, the catalyst comprises at least one hydrodehydrogenation element selected from the group formed by the elements of group VIB and the non-noble metal elements of group VIII of the periodic table, used alone or in mixtures.

[0026] Preferably, the catalyst according to the invention comprises an active phase which comprises, and preferably consists of, at least one metal of group VIB and at least one metal of group VIII.

[0027] Preferably, the group VIII element is selected from iron, cobalt and nickel, used alone or as a mixture, preferably nickel and cobalt. Preferably, the group VIB element is selected from tungsten and molybdenum, used alone or as a mixture. The following combinations of metals are preferred: nickel-molybdenum, cobalt-molybdenum, nickel-tungsten, cobalt-tungsten, highly preferred: nickel-molybdenum, nickel-tungsten. It is also possible to use combinations of three metals, for example nickel-cobalt-molybdenum.

[0028] The content of elements from group VIII in the catalyst is advantageously between 0.5% and 8% by weight of oxide, preferably between 0.5% and 6% by weight of oxide, highly preferably between 1.0% and 4% by weight of oxide, relative to the total weight of said catalyst. The content of elements from group VIB in the catalyst is advantageously between 1% and 30% by weight of oxide, preferably between 2% and 25% by weight of oxide, highly preferably between 5% and 20% by weight of oxide, even more preferably between 5% and 16% by weight of oxide, relative to the total weight of said catalyst.

[0029] Preferably, the catalyst used according to the invention can also contain a promoter element. This promoter element is selected from phosphorus, boron, silicon, and is highly preferably phosphorus. When the catalyst contains phosphorus, the phosphorus content, relative to the total weight of said catalyst, is advantageously about P 2 O5 0.5% to 10% by weight of the oxide, preferably P 2 O 5 1% to 6% by weight of the oxide, more preferably P 2 O 5 The oxide weight is 1% to 4% by weight.

[0030] (Carrier) The catalyst according to the invention comprises a support, which comprises at least one porous mineral matrix and an initial lattice constant a of a unit cell. 0 greater than 24.50 Å, preferably strictly greater than 24.50 Å, and zeolite beta.

[0031] The porous mineral matrix used in the support of the catalyst, also called binder, advantageously consists of at least one refractory oxide, preferably selected from the group formed by alumina, silica-alumina, clay, titanium oxide, boron oxide and zirconia, used alone or as a mixture. Preferably, the porous mineral matrix is ​​selected from alumina and silica-alumina, used alone or as a mixture. More preferably, the porous mineral matrix is ​​alumina. The alumina can advantageously be in any of the forms known to the person skilled in the art. Highly preferably, the alumina is gamma alumina, for example boehmite.

[0032] Preferably, the support comprises from 15% to 60% by weight, preferably from 15% to 40% by weight, highly preferably from 20% to 40% by weight, of a binder relative to the total weight of the support.

[0033] According to the present invention, the support has an initial lattice constant a 0 is strictly greater than 24.50 Å.

[0034] Preferably, the initial lattice constant a of the unit cell of the zeolite Y used is 0is 24.52 Å to 24.70 Å, preferably 24.52 Å to 24.65 Å, preferably 24.52 Å to 24.60 Å, and highly preferably 24.52 Å to 24.58 Å.

[0035] Given the initial lattice parameter a of the unit cell of zeolite Y, 0 is the initial lattice constant a of the zeolite Y used in the synthesis of the catalyst according to the invention 0 The value is

[0036] Initial lattice parameter a of the unit cell of zeolite Y 0 is determined by X-ray diffraction according to standard ASTM D3942-80.

[0037] Preferably, the zeolite Y content of the support is between 35% and 70% by weight, preferably between 50% and 70% by weight, preferably between 55% and 65% by weight, relative to the total weight of the support.

[0038] Said zeolites are advantageously defined in the "Atlas of Zeolite Framework Types, 6th Revised Edition", Ch. Baerlocher, LB McCusker, DH Olson, 6th Edition, Elsevier, 2007, Elsevier's classification.

[0039] According to a preferred embodiment of the invention, the zeolite Y having the specific characteristics defined above and suitable for implementing the support of the catalyst used in the process according to the invention is advantageously prepared from a zeolite Y of FAU structure type, which zeolite Y has an overall Si / Al atomic ratio of 2.3 to 2.8 after synthesis and is advantageously in the form of NaY after synthesis. Said zeolite Y of FAU structure type advantageously undergoes one or more steps of ion exchange followed by a dealumination step, by which the alkali cations belonging to groups IA and IIA of the periodic table present in the cation positions in the crudely synthesized zeolite Y of FAU structure type are replaced by NH 4 + Cation, preferably Na+ Cation is NH 4 + It is possible to partially or completely replace the cation.

[0040] Alkaline cation NH 4 + The partial or complete exchange with cations is from 80% to 100%, preferably from 85% to 99.5%, more preferably from 88% to 99% of the alkali cations NH 4 + It is understood to mean exchange with cations. At the end of one or more ion exchange steps, the residual amount of alkali cations in the zeolite Y, preferably Na + The residual amount of cations is the alkali cations originally present in the zeolite Y, preferably Na + Relative to the amount of cations, it is advantageously between 0% and 20%, preferably between 0.5% and 15%, preferably between 1.0% and 12%.

[0041] Preferably, this step involves carrying out multiple ion exchanges, which are carried out with a solution containing at least one ammonium salt selected from the group consisting of ammonium chlorates, sulfates, nitrates, phosphates or acetates, to remove the alkali cations present in the zeolite, preferably Na. + Preferably, the ammonium salt is ammonium nitrate NH 4 NO 3 It is.

[0042] Therefore, the alkali cations, preferably Na, in the zeolite Y at the end of one or more ion exchange steps are + The residual cation content is preferably adjusted so that the molar ratio of alkali cation / ammonium, preferably the Na / Al molar ratio, is 0:1 to 0:1, preferably 0:1 to 0.005:1, more preferably 0:1 to 0.008:1.

[0043] The desired alkali cation / aluminum ratio, preferably Na / Al, 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 advantageously varies between 20° C. and 100° C., preferably between 60° C. and 95° C., preferably between 60° C. and 90° C., more preferably between 60° C. and 85° C., even more preferably between 60° C. and 80° C. The number of ion exchanges advantageously varies between 1 and 10, preferably between 1 and 4.

[0044] The zeolite Y obtained, preferably of structure type FAU, can then undergo a dealumination step which may advantageously be carried out by any method known to the person skilled in the art. Preferably, the dealumination is carried out by a thermal treatment, optionally in the presence of water vapor (or "steaming") and / or by one or more acid attacks, advantageously by treatment with an aqueous solution of a mineral or organic acid.

[0045] Preferably, the dealumination step involves a heat treatment followed by one or more acid attacks, or only one or more acid attacks.

[0046] Preferably, the temperature at which the heat treatment, optionally in the presence of water vapor, to which the zeolite Y is subjected, is between 200° C. and 900° C., preferably between 300° C. and 900° C., and even more preferably between 400° C. and 750° C. The duration of the heat treatment is advantageously greater than or equal to 0.5 h, preferably between 0.5 h and 24 h, and highly preferably between 1 h and 12 h. In the case where the heat treatment is performed in the presence of water, the volume percentage of water vapor during the heat treatment is advantageously between 5% and 100%, preferably between 20% and 100%, and highly preferably between 40% and 100%. Any volume part present that is not water vapor is formed from air. The flow rate of the gas formed from water vapor and optionally air is advantageously less than 0.2 L·h -1 ·g -1 ~10L·h -1 ·g -1 (Zeolite Y).

[0047] The heat treatment allows the extraction of aluminum atoms from the structure of zeolite Y while keeping the overall Si / Al atomic ratio of the treated zeolite unchanged.

[0048] The step of heat treatment in the presence of water vapor is advantageously suitable for carrying out the catalyst support used in the process according to the invention and has a lattice constant a 0 may be repeated as many times as necessary to obtain a zeolite Y where m is strictly greater than 24.50 Å.

[0049] The step of heat treatment, optionally in the presence of water vapor, is advantageously followed by a step of acid attack. The aluminic acid debris resulting from the step of heat treatment in the presence of water vapor partially blocks the porosity of the dealuminated zeolite. The acid attack makes it possible to partially or completely remove such aluminic acid debris; the acid attack thus makes it possible to unblock the porosity of the dealuminated zeolite.

[0050] The acid attack may advantageously be carried out by suspending the zeolite Y, which may have undergone a prior 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° C. and 100° C., preferably between 60° C. and 95° C., preferably between 60° C. and 90° C., more preferably between 60° C. and 80° C. The duration of the acid attack is advantageously between 5 minutes and 8 hours, preferably between 30 minutes and 4 hours, preferably between 1 hour and 2 hours.

[0051] Upon completion of the step or steps of heat treatment, optionally in the presence of water vapor, and the optional acid attack step, said method for modifying zeolite Y advantageously comprises removing the alkali cations still present in the cation sites in the zeolite Y, preferably Na + The ion exchange step is carried out in a manner similar to the ion exchange step described above.

[0052] Optionally, one or more steps of heat treatment in the presence of water vapor and an optional acid attack step and optionally an alkali cation, preferably Na + At the end of the step of partial or complete exchange of cations, the method for modifying the zeolite Y may include a calcination step, which makes it possible to remove organic species present in the zeolite porosity, such as those provided by the acid attack step or the step of partial or complete exchange of alkali cations, and in addition makes it possible to generate the proton form of the zeolite Y and to make it acidic for the purposes of its application.

[0053] The calcination may advantageously be carried out in a muffle or tubular furnace, under dry air or under an inert atmosphere, in a swept or transverse bed. The calcination temperature is advantageously between 200° C. and 800° C., preferably between 450° C. and 600° C., preferably between 500° C. and 550° C. The duration of the calcination held is advantageously between 1 and 20 hours, preferably between 6 and 15 hours, preferably between 8 and 12 hours.

[0054] Therefore, the initial lattice constant a of the unit cell of the obtained zeolite Y 0 is strictly greater than 24.50 Å.

[0055] The resulting zeolite Y advantageously has a specific surface area, measured by nitrogen physical adsorption using the BET method, of between 550 and 1000 m 2 / g, preferably 600 to 900m 2 / g, preferably 650 to 800m 2 / g.

[0056] According to the present invention, the support also comprises zeolite beta.

[0057] Zeolite beta is generally synthesized from a reaction mixture containing a structuring agent. The use of structuring agents is well known to those skilled in the art: for example, patent US 3,308,069 describes the use of tetraethylammonium hydroxide, and patent US 5,139,759 describes the use of tetraethylammonium cations derived from tetraethylammonium chloride compounds. Another standard method for preparing zeolite beta is given in the book "Verified Synthesis of Zeolitic Materials".

[0058] The zeolite beta used in the support according to the invention preferably has an overall SAR atomic ratio of between 10 and 100, preferentially between 20 and 50, more preferably between 20 and 30. The zeolite beta used in the support according to the invention advantageously has a specific surface area, measured by nitrogen physisorption according to the BET method, of between 400 and 800 m 2 / g, preferably 500 to 750m 2 / g, preferably 550 to 700m 2 / g.

[0059] Preferably, the zeolite beta content of the support is between 5% and 15% by weight, preferably between 7% and 14% by weight, preferably between 8% and 12% by weight, relative to the total weight of said support.

[0060] Preferably, the carrier comprises, preferably consists of: - Initial lattice constant a of the unit cell 0 strictly greater than 24.50 Å: 35% to 70%, preferably 50% to 70%, preferably 55% to 65%, by weight relative to the total weight of the support; - zeolite beta: from 5% to 15%, preferably from 7% to 14%, preferably from 8% to 12%, relative to the total weight of the support; and - at least one porous mineral matrix: from 15% to 60% by weight, preferably from 15% to 40% by weight, highly preferably from 20% to 40% by weight, relative to the total weight of the support;

[0061] According to the invention, the weight ratio of said zeolite Y to said zeolite beta in the catalyst is 5-12.

[0062] Preferably, the weight ratio of said zeolite Y to said zeolite Beta in the catalyst is 5-10, preferably 5-8.

[0063] Preferably, the zeolite Y content of the catalyst is between 18% and 69% by weight relative to the total weight of said catalyst.

[0064] Preferably, the zeolite beta content of the catalyst is between 2% and 15% by weight relative to the total weight of the catalyst.

[0065] Preferably, the content of at least one porous mineral matrix in said catalyst is between 8% and 59% by weight relative to the total weight of said catalyst.

[0066] The Y / Beta ratios within these ranges of the hydrocracking catalyst according to the invention make it possible to obtain improved conversion activity in cuts boiling below 216° C. (naphtha and gas) when said catalyst is used in the hydrocracking process according to the invention, in comparison with prior art catalysts, i.e. those having different weight ratios or contents and / or zeolites with lower lattice parameters.

[0067] (Catalyst Preparation) The catalyst is advantageously prepared by conventional methods used in the art.

[0068] In particular, the catalyst is prepared by a preparation method comprising the following steps: - preparing the carrier; comprising: At least one porous mineral matrix is ​​formed with an initial lattice constant a 0 the weight ratio of said zeolite Y to said zeolite beta in the catalyst is between 5 and 12, preferably between 5 and 10, preferably between 5 and 8; and forming the mixture; - introducing on the support at least one hydrodehydrogenating element selected from the group formed by the elements of group VIB of the periodic table, preferably nickel and cobalt, the non-noble metal elements of group VIII of the periodic table, preferably iron, cobalt, nickel, and mixtures thereof, preferably nickel and cobalt, and mixtures thereof; adding at least one precursor of said element during shaping so as to incorporate at least a portion of said element, impregnating the support with at least one precursor of said element, an optional step of drying and / or calcining at the end of the preparation of the support and / or of introducing at least one hydrodehydrogenating element.

[0069] More specifically, the catalyst is prepared according to a preparation method comprising the following steps: a) preparing a zeolite Y having the specific crystallographic characteristics claimed by the above process, b) preparing zeolite beta; c) mixing with a porous mineral matrix and shaping to obtain a carrier; d) introducing at least one hydrodehydrogenating element onto the support by at least one of the following methods: - adding at least one precursor of said element during shaping to introduce at least a portion of said element, impregnating a support with at least one precursor of said hydrodehydrogenating element, Optionally, at the end of each of the preparation steps a) or b) or c) or d) a drying and / or calcination of the product obtained is carried out.

[0070] The carrier may be advantageously shaped by any technique known to those skilled in the art, for example by extrusion, pelletizing, the drop congealing (oil drop) method, granulation on a rotating plate or any other method known to those skilled in the art.

[0071] The supports are preferably formed into granules of various shapes and sizes. They are generally used in the form of cylindrical or multilobed pellets, for example trilobed, tetralobed or multilobed pellets, of straight or twisted form, but may be produced and used in the form of crushed powders, pastilles, rings, beads or wheels. However, the catalyst is advantageously in the form of pellets with a diameter of 0.5 to 5 mm, more particularly 0.7 to 3 mm, monolayer and more particularly 1.0 to 2.5 mm. The shape is cylindrical (which may or may not be hollow), twisted cylindrical, multilobed (for example 2, 3, 4 or 5 lobes) or annular. Any other shape may be used.

[0072] One suitable forming method consists in co-kneading both said zeolites with a binder, preferably alumina, in the form of a wet gel for a few tens of minutes, preferably between 10 and 40 minutes, then forcing the paste thus obtained through a die to form pellets with a diameter preferably between 0.5 and 5 mm.

[0073] According to another of the preferred forming methods, the two zeolites can be introduced during the synthesis of the porous mineral matrix. For example, according to this preferred embodiment of the invention, the zeolites Y and Beta are added during the synthesis of the porous mineral matrix, for example a silicoaluminate matrix: in this case, the two zeolites can advantageously be added to a mixture consisting of an alumina compound and a completely soluble silica compound in an acid medium.

[0074] The elements of Group VIB and / or Group VIII may optionally be introduced by adding at least one compound of said elements during the shaping step to introduce at least a portion of said elements.

[0075] The introduction of at least one hydrodehydrogenating element may advantageously be accompanied by the introduction of at least one promoter element selected from phosphorus, boron, silicon, preferably phosphorus, and optionally by the introduction of an element of group VIIA and / or group VB. The shaped solid is optionally dried at a temperature between 60° C. and 250° C. and optionally calcined at a temperature between 250° C. and 800° C. for a period between 30 minutes and 6 hours.

[0076] The step of introducing at least one hydrodehydrogenating element is advantageously carried out by methods known to those skilled in the art, in particular by one or more operations of impregnating the shaped and calcined or dried, preferably calcined, support with a solution containing precursors of elements of groups VIB and / or VIII, optionally precursors of at least one promoter element and optionally precursors of at least one element of groups VIIA and / or VB.

[0077] Preferably, said step d) is carried out by a method of dry impregnation with a solution containing the hydrodehydrogenating functional groups, i.e. precursors of the elements of group VIB and / or group VIII, optionally followed by a drying step and preferably without a calcination step.

[0078] In cases where the catalyst of the invention contains a non-noble Group VIII metal, the Group VIII metal is preferably introduced by one or more operations of impregnation of the shaped and calcined support, either after or simultaneously with the Group VIB operation.

[0079] The introduction of at least one hydrogenating / dehydrogenating element can optionally be followed by drying at a temperature between 60°C and 250°C and, optionally, by calcination at a temperature between 250°C and 800°C.

[0080] The sources of molybdenum and tungsten are advantageously selected from the oxides and hydroxides, molybdic and tungstic acids and their salts, in particular the ammonium salts, such as ammonium molybdate, ammonium heptamolybdate and ammonium tungstate, phosphomolybdic acid, phosphotungstic acid and their salts, silicomolybdic acid, silicotungstic acid and their salts. Use is preferably made of the oxides and ammonium salts, such as ammonium molybdate, ammonium heptamolybdate and ammonium tungstate.

[0081] Sources of non-noble Group VIII elements that may be used are well known to those skilled in the art. For example, for non-noble metals, use may be made of nitrates, sulfates, hydroxides, phosphates, halides such as chlorides, bromides and fluorides, carboxylates such as acetates and carbonates.

[0082] The preferred source of phosphorus is orthophosphate H 3 PO 4However, its salts and esters, such as ammonium phosphate, are also suitable. Phosphorus may be introduced, for example, in the form of a mixture of phosphoric acid with nitrogen-containing basic organic compounds, such as aqueous ammonia, primary and secondary amines, cyclic amines, compounds of the pyridine and quinoline series and compounds of the pyrrole series. Tungstophosphoric or tungstomolybdic acids may be used.

[0083] The phosphorus content is adjusted to form mixed compounds, such as tungsten-phosphorus or molybdenum-tungsten-phosphorus, in the solution and / or on the support, but this is not intended to limit the scope of the present invention. These mixed compounds can be heteropolyanions. These compounds can be, for example, Anderson heteropolyanions.

[0084] The source of boron may be boric acid, preferably orthoboric acid H 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.

[0085] Many sources of silicon may be used. Thus, use may be made of ethyl orthosilicate, Si(OEt). 4 , siloxanes, polysiloxanes, silicones, silicone emulsions, silica 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 advantageously added, for example, by impregnation with a solution of ethyl silicate in a water / alcohol mixture. Silicon may be added, for example, by impregnation with a silicon compound of silicone or silicic acid type suspended in water.

[0086] Sources of Group VB elements that can be used are well known to those skilled in the art. For example, among sources of niobium, use may be made of oxides such as niobium pentoxide (Nb 2 O 5 , Nb niobate 2 O 5 H 2 O, niobium hydroxide and polyoxoniobates, formula Nb(OR1) 3 (wherein R1 is an alkyl group), niobium alkoxide, niobium oxalate NbO(HC 2 O 4 ) 5 or ammonium niobate. Preference is given to using niobium oxalate or ammonium niobate.

[0087] The sources of Group VIIA elements that can be used are well known to those skilled in the art. For example, fluoride anions can be introduced in the form of hydrofluoric acid or its salts. These salts are formed with alkali metals, ammonium or organic compounds. In the case of organic compounds, the salts are advantageously formed in the reaction mixture by reaction between the organic compound and hydrofluoric acid. Hydrolyzable compounds capable of releasing fluoride anions in water, such as ammonium fluorosilicate (NH 4 ) 2 SiF 6 , silicon tetrafluoride SiF 4 or sodium tetrafluoride 2 SiF 6 Fluorine can be introduced, for example, by impregnation with an aqueous solution of hydrofluoric acid or ammonium fluoride.

[0088] (hydrocracking method) The catalyst according to the invention is advantageously used in hydrocracking processes, in particular for the production of naphtha. The catalyst used in hydrocracking processes, such as the process according to the invention, can advantageously be in sulfided form. The Group VIB metals and / or non-noble Group VIII metals of said catalyst are therefore present in sulfided form.

[0089] The catalysts used in the process according to the invention are advantageously subjected to a prior sulfurization treatment in order to convert, at least in part, the metallic species into the sulfurized form before they are brought into contact with the feedstock to be treated. This activation treatment by sulfurization can be carried out either in situ, i.e. in the reactor, or ex situ, by any of the methods well known to the person skilled in the art and already described in the literature.

[0090] Conventional sulfurization processes well known to those skilled in the art consist of heating the catalyst in the presence of hydrogen sulfide (high purity or, for example, under a flow of hydrogen-hydrogen sulfide mixture) at temperatures between 150° C. and 800° C., preferably between 250° C. and 600° C., typically in a flow-through bed reaction zone.

[0091] Another subject of the invention is a process for hydrocracking at least one hydrocarbon feedstock, preferably in liquid form, in which at least 50% by weight of the compounds of said feedstock have an initial boiling point above 300° C. and a final boiling point below 650° C., said hydrocracking being carried out in the presence of a catalyst according to the invention, in which the temperature is between 200° C. and 480° C., in which the total pressure is between 1 MPa and 25 MPa, in which the volume ratio of hydrogen per volume of hydrocarbon feedstock is between 80 and 5000 liters / liter, in which the hourly space velocity (HSV), defined by the ratio of the volumetric flow rate of the hydrocarbon feedstock, which is preferably liquid, per volume of catalyst charged in the reactor, is between 0.1 and 50 h . -1 It is.

[0092] 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 skilled artisan and which makes it possible to reduce the content of certain pollutants, such as nitrogen, sulfur or metals, in the feedstock (see below). The operating conditions of this pretreatment section (HSV, temperature, pressure, hydrogen flow rate, liquids, reaction configuration, etc.) may vary widely according to the knowledge of the skilled artisan.

[0093] (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, in which at least 50% by weight of the compounds have an initial boiling point above 300° C. and a final boiling point below 650° C., preferably at least 60% by weight of the compounds, preferably at least 75% by weight of the compounds, more preferably at least 80% by weight of the compounds have an initial boiling point above 300° C. and a final boiling point below 650° C.

[0094] The feedstocks are advantageously chosen from LCO (Light Cycle Oil, light gas oils obtained from catalytic cracking units), atmospheric distillates, vacuum distillates, for example gas oils obtained from direct distillation of crude oil or from conversion units, for example FCC, coking or visbreaking units, feedstocks originating from units for the extraction of aromatics from lubricant base stocks or feedstocks resulting from the solvent dewaxing of lubricant base stocks, distillates originating from processes for the fixed-bed or ebullated-bed desulfurization or hydroconversion of AR (atmospheric residues) and / or VR (vacuum residues) and / or deasphalted oils, and paraffins obtained from the Fischer-Tropsch process, used alone or as a mixture. Mention may be made of feedstocks of renewable origin (for example vegetable oils, animal fats, oils from the hydrothermal conversion or pyrolysis of lignocellulosic biomass) and also plastic pyrolysis oils. The above list is not limiting. The boiling point T5 of said feedstock is preferably above 300°C, preferably above 340°C, i.e. 95% of the compounds present in the feedstock have a boiling point above 300°C, suitably above 340°C.

[0095] The nitrogen content of the feedstock treated in the process according to the invention is advantageously greater than 500 ppm by weight, preferably between 500 and 10,000 ppm by weight, more preferably between 700 and 4000 ppm by weight, even more preferably between 1000 and 4000 ppm by weight. The sulphur content of the feedstock treated in the process according to the invention is advantageously between 0.01% and 5% by weight, preferably between 0.2% and 4% by weight, even more preferably between 0.5% and 3% by weight.

[0096] The feedstock may optionally contain metals. The cumulative content of nickel and vanadium in the feedstock treated in the process according to the invention is preferably less than 1 ppm by weight.

[0097] The feedstock may optionally contain asphaltenes. The asphaltene content is generally less than 3000 ppm by weight, preferably less than 1000 ppm by weight, and even more preferably less than 200 ppm by weight.

[0098] Advantageously, when the catalyst according to the invention is used after the hydrotreating section described above, the nitrogen, sulfur, metal or asphaltene content in the liquid injected into the process according to the invention using the catalyst according to the invention is reduced. Preferably, the organic nitrogen content in the feedstock treated in the hydrocracking process according to the invention is then, after hydrotreating, between 0 and 200 ppm, preferably between 0 and 50 ppm, even more preferably between 0 and 30 ppm. The sulfur content is preferably less than 1000 ppm, the asphaltene content is preferably less than 200 ppm, while the metal (Ni or V) content is less than 1 ppm.

[0099] The hydrocracking process according to the invention may include a fractionation step between pretreatment of the feedstock and the hydrocracking reactor(s) using the catalyst according to the invention. In the preferred case where the hydrocracking process is carried out without fractionation (gas and liquid) between pretreatment and the hydrocracking reactor(s) using the catalyst according to the invention, the nitrogen and sulfur removed from the liquid after pretreatment are NH 3 and H 2 In the form of S, it is injected into the reactor or reactors containing the catalyst according to the invention.

[0100] According to the present invention, the temperature during the process for hydrocracking the hydrocarbon feedstock according to the present invention is 200°C to 480°C, the total pressure is 1MPa to 25MPa, the ratio of the volume of hydrogen per volume of the hydrocarbon feedstock is 80 to 5000 liters / liter, and the hourly space velocity (HSV), defined by the ratio of the volumetric flow rate of the hydrocarbon feedstock per volume of the catalyst loaded in the reactor, is 0.1 to 50 h -1 It is.

[0101] Preferably, the hydrocracking process according to the invention is carried out in the presence of hydrogen at a temperature between 250° C. and 480° C., preferably between 320° C. and 450° C., highly preferably between 330° C. and 435° C., under a pressure between 2 and 25 MPa, highly preferably between 3 and 20 MPa, for 0.1 to 20 h. -1 , preferably 0.1 to 6 hours -1 , preferably 0.2 to 3 hours -1 The amount of hydrogen introduced is set so that the volume ratio of hydrogen volume (liters) / hydrocarbon volume (liters) is 100 to 2000 L / L.

[0102] The process can be carried out in one or two steps depending on the targeted degree of conversion of the feedstock, with or without recycling the unconverted portion. The catalyst according to the invention can be used in a non-limiting manner in one or two steps of the hydrocracking process, alone or in combination with another hydrocracking catalyst.

[0103] The operating conditions used in the process according to the invention generally make it possible to obtain a conversion per pass of more than 15% by weight, and even more preferably between 20% by weight and 100% by weight, to products having a boiling point below 340° C., and even better below 370° C.

[0104] The examples illustrate the invention but do not limit its scope.

[0105] (Example) Example 1 - Preparation of Comparative Catalyst A The preparation by shaping of the support for catalyst A is carried out by kneading-extrusion of 60% by weight of commercial zeolite Y (zeolite CBV712 from Zeolyst) and 10% by weight of commercial zeolite beta (zeolite CP814e from Zeolyst) in the presence of commercial boehmite (Pural SB3 from SASOL). The lattice parameter of zeolite Y is 24.35 Å and SiO 2 / Al 2 O 3 The molar ratio is 12, and the specific surface area is 850 m, measured by nitrogen physical adsorption using the BET method. 2 / g, and SiO of zeolite beta 2 / Al 2 O 3 The molar ratio is 25, and the specific surface area is 670 m, as measured by nitrogen physical adsorption according to the BET method. 2 The extrudates obtained are dried at 80° C. and then calcined at 600° C. in moist air (5% by weight water per kg of dry air). The calcined support contains, on a dry basis, 60% by weight of zeolite Y, 10% by weight of zeolite beta and 30% by weight of alumina, i.e. a weight ratio of Y / Beta in the catalyst=6.

[0106] Catalyst A is prepared by dry impregnation of the resulting support with an aqueous solution containing the elements Ni, Mo. This solution is obtained by dissolving the following precursors in water: nickel nitrate and ammonium heptamolybdate. The amount of precursor in the solution is adjusted according to the targeted concentration on the final catalyst. After dry impregnation, the catalyst is dried in air at 120°C.

[0107] The mass percentages in the catalyst are as follows, on a dry basis: molybdenum (MoO 3 % by weight, and nickel (in the form of NiO) 3.3% by weight.

[0108] Example 2 - Preparation of Comparative Catalyst B The preparation by shaping of the support for catalyst B is carried out by kneading-extrusion in the presence of 60% by weight of zeolite Y and 10% by weight of commercial zeolite beta (zeolite CP814e from Zeolyst) in commercial boehmite (Pural SB3). The lattice parameter of zeolite Y is 24.42 Å and SiO 2 / Al 2 O 3 The molar ratio is 5.2, and the specific surface area is 800 m, measured by nitrogen physical adsorption using the BET method. 2 / g, and SiO of zeolite beta 2 / Al 2 O 3 The molar ratio is 25, and the specific surface area is 670 m, as measured by nitrogen physical adsorption according to the BET method.2 The pellets obtained are dried at 80° C. and then calcined at 600° C. in moist air (5% by weight water per kg of dry air). The calcined support contains, on a dry basis, 60% by weight of zeolite Y, 10% by weight of zeolite beta and 30% by weight of alumina, i.e., a weight ratio of Y / Beta in the catalyst=6.

[0109] Catalyst B is prepared by dry impregnation of the resulting support, using an aqueous solution containing the elements Ni, Mo. This solution is obtained by dissolving the following precursors in water: nickel nitrate and ammonium heptamolybdate. The amount of precursor in the solution is adjusted according to the targeted concentration on the final catalyst. After dry impregnation, the catalyst is dried in air at 120°C.

[0110] The mass percentages in the catalyst are as follows, on a dry basis: molybdenum (MoO 3 % by weight, and nickel (in the form of NiO) 3.3% by weight.

[0111] Example 3 - Preparation of Catalyst C in Accordance with the Invention The preparation by shaping of the support for catalyst C is carried out by kneading-extrusion in the presence of 60% by weight of zeolite Y and 10% by weight of commercial zeolite beta (CP814e) in commercial boehmite (Pural SB3). The lattice parameter of zeolite Y is 24.54 Å and SiO 2 / Al 2 O 3 The molar ratio is 5.2, and the specific surface area is 830 m, measured by nitrogen physical adsorption according to the BET method. 2 / g, and SiO of zeolite beta 2 / Al 2 O 3 The molar ratio is 25, and the specific surface area is 670 m, as measured by nitrogen physical adsorption according to the BET method. 2The pellets obtained are dried at 80° C. and then calcined at 600° C. in moist air (5% by weight water per kg of dry air). The calcined support contains, on a dry basis, 60% by weight of zeolite Y, 10% by weight of zeolite beta and 30% by weight of alumina, i.e., a weight ratio of Y / Beta in the catalyst=6.

[0112] Catalyst C is prepared by dry impregnation of the resulting support, using an aqueous solution containing the elements Ni, Mo. This solution is obtained by dissolving the following precursors in water: nickel nitrate and ammonium heptamolybdate. The amount of precursor in the solution is adjusted according to the targeted concentration on the final catalyst. After dry impregnation, the catalyst is dried in air at 120°C.

[0113] The mass percentages in the catalyst are as follows: molybdenum (MoO 3 % by weight, and nickel (in the form of NiO) 3.3% by weight.

[0114] Example 4 The performance of the above catalysts is evaluated in a single step in the hydrocracking of feedstocks containing vacuum distillate fractions and gas oils using an isothermal test pilot unit in a downflow configuration.

[0115] The test feedstock undergoes hydrotreating (HDT). After the hydrotreating step, the density of the test feedstock at 15° C. is 0.8755 g / mL, the residual nitrogen content is 23 ppm by weight, and the residual sulfur content is 16 ppm by weight. The initial boiling point of the simulated distillation for the test feedstock after hydrotreating is 163.3° C., and the end point is at 578.7° C. The 50% point of the simulated distillation is 391.7° C. To simulate the partial pressures of hydrogen sulfide and ammonia generated by the HDT step of the process, the test feedstock is spiked with DMDS and aniline, respectively, to obtain 8820 ppm by weight of sulfur and 1900 ppm by weight of nitrogen in the final spiked feedstock.

[0116] Each catalyst was evaluated separately and sulfided prior to hydrocracking tests under straight run gas oil (SRGO) feedstock (i.e., gas oil feedstock derived from direct distillation of crude oil) with 4 wt.% dimethyl sulfide (DMDS) and 2 wt.% aniline. The HSV for the sulfidation run was 2h. -1 (HSV = hourly space velocity), H 2 The volume ratio of the feedstock is 1000NL / L, the total pressure is 140 bar (ie, 14.0 MPa), and the holding temperature is 350°C for 6 hours.

[0117] After sulfurization, the operating conditions are adjusted to those used for the hydrocracking tests: HSV 1.5h -1 , H 2 / feed volume ratio of 1000 NL / L, total pressure of 140 bar (i.e., 14.0 MPa). The reactor temperature is adjusted to target a net conversion of 65 wt. % of the 216° C.+ fraction from the feed after 150 hours.

[0118] Net conversion is defined as the yield of the cut (or fraction) boiling below 216°C minus the yield of the cut present in the test feedstock boiling below 216°C.

[0119] The performance of the catalysts is compared with that of Catalyst B, which is considered as the benchmark, and is reported in Table 1.

[0120] The relative activity in degrees Celsius (°C) is obtained from the temperature difference between the temperature at which a net conversion of 65% is obtained for the reference catalyst B and that obtained for the catalyst under evaluation. The relative yield of the 68-216°C cut is determined as the difference between the yield of the catalyst under evaluation and the yield of reference catalyst B obtained at a net conversion of 65 wt% of the 216°C+ cut in the two cases. Positive values ​​indicate higher activity or yield.

[0121] [Table 1]

[0122] The results reported in the above table show that catalyst C according to the invention, having a combination of zeolites Y and Beta in a mass ratio of 6, with the lattice parameter of the Y zeolite being 24.54 Å, makes it possible to obtain a gain in activity in the conversion of fractions boiling above 216° C. to fractions boiling below 216° C. (naphtha and gas oil) relative to comparative catalysts A and B, which use Y zeolites with lower lattice parameters and comparable Y / Beta ratios, without loss of selectivity or yield for the naphtha fraction.

[0123] Catalyst C also shows a slight improvement in naphtha fraction yield relative to Catalyst A.

Claims

1. A hydrocracking catalyst comprising at least one hydrodehydrogenating element and a support, the hydrodehydrogenating element being selected, alone or in mixture, from the group formed by the elements of group VIB and the non-noble metal elements of group VIII of the periodic table, the support comprising at least one porous mineral matrix, the initial lattice constant of the unit cell being a ０ 1. A hydrocracking catalyst comprising zeolite Y having a pore size strictly greater than 24.50 Å, and zeolite beta, wherein the weight ratio of said zeolite Y to said zeolite beta in the catalyst is 5-12.

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

3. Catalyst according to claim 1, wherein the group VIB element is selected from tungsten and molybdenum, alone or in a mixture, and the content of group VIB element is between 1% and 30% by weight of oxide, preferably between 2% and 25% by weight of oxide, highly preferably between 5% and 20% by weight of oxide, and even more preferably between 5% and 16% by weight of oxide, relative to the total weight of the catalyst.

4. The catalyst contains phosphorus, and the phosphorus content is, relative to the total weight of the catalyst, ２ O ５ 0.5% to 10% by weight of the oxide, preferably P ２ O ５ 1.0 wt% to 6 wt% by weight of the oxide, more preferably P ２ O ５ 10. The catalyst of claim 1, wherein the oxide is present in an amount of 1.0% to 4% by weight.

5. The initial lattice constant a of the unit cell of zeolite Y ０ 2. The catalyst of claim 1, wherein the .lambda. is 24.52 Å to 24.70 Å, preferably 24.52 Å to 24.65 Å, preferably 24.52 Å to 24.60 Å, highly preferably 24.52 Å to 24.58 Å.

6. Catalyst according to claim 1, wherein the zeolite Y content of the catalyst is between 18% and 69% by weight relative to the total weight of the catalyst.

7. Catalyst according to claim 1, wherein the zeolite beta content of the catalyst is between 2% and 15% by weight relative to the total weight of the catalyst.

8. Catalyst according to claim 1, wherein the content of at least one porous mineral matrix of said catalyst is between 8% and 59% by weight relative to the total weight of said catalyst.

9. Catalyst according to claim 1, wherein the weight ratio of said zeolite Y to said zeolite beta in the catalyst is between 5 and 10, preferably between 5 and 8.

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