Process for producing middle distillates by co-processing of mineral feedstocks with renewable feedstocks involving a range of catalysts including a beta zeolite-based catalyst - Patent Application 20070122997

Abstract

The present invention provides a method for producing middle distillates from at least one fossil hydrocarbon feedstock, comprising the steps of hydrotreating the feedstock and hydrocracking the hydrotreated feedstock, wherein the hydrocracking step comprises contacting the hydrotreated feedstock with at least one first catalyst comprising at least one Group VIB metal and / or at least one Group VIII metal, a support comprising at least one zeolite having at least a series of channels, the openings of which are defined by rings of 12 oxygen atoms, and at least one binder, and contacting all of the effluent from the above step with a second catalyst comprising at least one Group VIB metal and / or at least one Group VIII metal, a support comprising at least one zeolite of the BEA structure code, and at least one binder.

Description

[Technical Field]

[0001] The present invention relates to a process for producing middle distillates comprising a hydrotreating step and a hydrocracking step, the hydrocracking step being characterized by utilizing two catalysts in two separate hydrocracking zones operated in series.

[0002] This process converts a range of hydrocarbon feedstocks into desired products (naphtha, jet fuel, diesel). These hydrocarbon feedstocks include "fossil" feedstocks such as vacuum distillate (VD) or vacuum gas oil (VGO) obtained from direct distillation of crude oil or conversion units such as FCC, coking, H-oil, or visbreaking units; feedstocks obtained from the Fischer-Tropsch process; feedstocks obtained from the conversion of bituminous and shale oils; and at least one renewable feedstock selected from vegetable oil, algae oil, cooking oil, and animal fat, which may be virgin or used, alone or in mixtures, as well as feedstocks derived from renewable sources such as biomass, plastics, tires, and household waste, alone or in mixtures. These feedstocks may optionally contain metals and / or nitrogen and / or oxygen and / or sulfur.

[0003] The object of the process according to the invention is to produce middle distillates, which essentially comprise petroleum fractions having initial and final boiling points in the range of 130-300°C, and gas oil fractions having initial and final boiling points in the range of 220-390°C.

[0004] In particular, the present invention relates to a method for producing middle distillates from a hydrocarbon feedstock, preferably of the vacuum distillate type, alone or in a mixture with at least one renewable feedstock selected from vegetable oils, algae oils, cooking oils and animal fats, which may be virgin or used, or as a feedstock obtained from the reprocessing of biomass / plastics / tires and household waste, alone or in a mixture, the method comprising a hydrotreating step and a hydrocracking step, the hydrocracking step being carried out in the presence of a train of two specific catalysts employed in two separate catalytic zones, the entire effluent obtained from the first catalytic zone being sent directly to the second catalytic zone in contact with the second catalyst, without intermediate separation of the gas phase between the two catalytic zones of the second hydrocracking step.

[0005] In particular, the first catalyst utilized in the first catalytic zone of the hydrocracking step comprises at least one metal from Group VI of the periodic table and / or at least one metal from Group VIII, and a support comprising at least one large pore zeolite (12MR), which allows for a fairly significant conversion of the hydrocarbon feedstock upstream of the second catalyst.

[0006] The second catalyst utilized in the second catalytic zone of the hydrocracking step, according to the present invention, comprises at least one Group VIB metal and / or at least one Group VIII metal of the Periodic Table, and a support comprising at least one zeolite of the BEA structure type. [Background technology]

[0007] Processes for producing middle distillates, including hydrocracking heavy petroleum fractions, are currently essential in refining and allow refiners to refine lighter fractions, such as gasoline, jet fuel, and diesel, from surplus and easily unimprovable heavy feedstocks that are required by refiners to meet their production needs. Certain hydrocracking processes also allow for the production of highly refined residues that can provide excellent base stocks for the production of oils. Compared with catalytic cracking (FCC), the advantage of catalytic hydrocracking is that it produces very high-quality middle distillates. Conversely, the gasoline produced has a much lower octane rating than that obtained from catalytic cracking.

[0008] The flexibility of this process derives from three main factors: the operating conditions used, the type of catalyst utilized, and the possibility of hydrocracking the hydrocarbon feedstock in one or two steps. Therefore, it is suitable for processing and converting any type of hydrocarbon feedstock, as long as it is suitable for injection into the catalytic reactor in liquid form. In particular, feedstocks obtained by the distillation of crude oil, either alone or in mixtures, can also be used, as can vegetable oils and animal fats.

[0009] This can be carried out in a single step in one or more reactors in series in the presence of a first catalyst that not only hydrocracking the hydrocarbon feedstock to lower boiling point products but also converts residual organic compounds containing sulfur and nitrogen to sulfides and ammonia, respectively.

[0010] The hydrocracking catalysts used in the processes for purifying middle distillates are bifunctional, i.e., they combine an acid function with a hydro-dehydrotreating function. The acid function is generally of the order of 150-1000 m, such as halogenated (especially chlorinated or fluorinated) alumina, combinations of boron and aluminium oxide, amorphous silica-alumina and zeolites. 2 ·g -1The hydrogenation-dehydrogenation function is provided by one or more metals from Group VIB of the Periodic Table of 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.

[0011] The balance between the two functions is one of the parameters that govern the activity and selectivity of a catalyst. The weak acid function and the strong hydro-dehydrotreating function are less active, but generally at high temperatures (above 390-400 °C) and low feed space velocities (HSV, expressed as the volume of feed processed per unit volume of catalyst and per hour, is generally 2 h -1 ) and gives a catalyst with very good selectivity to middle distillates (jet fuel and diesel). Conversely, a strong acid function and a weak hydro-dehydrotreating function gives a catalyst that is active but has poorer selectivity to middle distillates.

[0012] One type of conventional hydrocracking catalyst is based on moderately acidic amorphous oxides, such as silica-alumina. These systems are used to produce high-quality middle distillates and, in some cases, oil bases. A drawback of these catalysts based on amorphous supports is their low activity.

[0013] For example, catalysts containing zeolite Y or catalysts containing, for example, partly zeolite beta exhibit higher activity than silica-alumina but lower selectivity for middle distillates (jet fuel and gas oil).

[0014] Generally, hydrocracking catalysts containing only zeolite Y do not make it possible to obtain good low-temperature properties for petroleum fractions (regarding the crystal appearance point) as well as for light oil fractions (regarding the cloud point, pour point, and plugging point of the low-temperature filters of the fractions). These values ​​are highly correlated with the higher-boiling normal paraffins present in these fractions. In order to meet fuel specifications for low-temperature properties, it may be necessary for the refiner to lower the final boiling point of the fraction (reducing the content of high-boiling paraffins) to the benefit of the heavy fractions that are not or hardly improvable, with the direct effect of a decrease in their yield.

[0015] The prior art refers to numerous studies aimed at improving the selectivity of zeolite catalysts for middle distillates in hydrocracking processes. The latter generally consist of a transition metal-based hydro-dehydrogenation phase deposited on a support containing a zeolite, usually zeolite USY. The hydro-dehydrogenation phase is generally in the form of a sulfide of the transition metal.

[0016] For example, studies have been conducted on the use of catalysts containing zeolite Y modified, for example, by dealumination through steaming or acid attack, on composite catalysts, or on the use of small crystals of zeolite Y. Other patent applications, such as U.S. Pat. No. 7,585,405, describe the use of catalysts containing mixtures of zeolites, such as zeolite beta and USY, to improve the performance of hydrocracking catalysts. Fine-tuning of the USY / β ratio is necessary to maximize the yield of middle distillates, which is required here, in particular, by precisely selecting zeolite USY with a lattice parameter between 24.37 and 24.44 Å. No mention is made of changes in the relative yields of gas oil and petroleum fractions.

[0017] In contrast, patent applications such as WO 08085517 provide for the use of a single zeolite source for the formulation of catalysts. It is taught that the incorporated zeolite beta preferably has an SAR of less than 30 and undergoes little or no post-treatment after removal of the structuring agent used in its preparation. Compared to other catalyst formulations containing zeolite beta that have undergone various heat treatments in the presence of steam (steaming), an increase in middle distillate yield of the order of 2-3 percentage points has been demonstrated, without specifying the respective yields of gas oil or petroleum fractions.

[0018] Various technical solutions have been proposed which, in principle, result in an improvement in the yield of middle distillates when the catalyst or operating conditions of the hydrocracking process are changed, but this improvement is generally brought about by an increase in the yield of light oil fractions, an increase in the yield of petroleum fractions whose yield remains low or even zero.

[0019] One alternative consists in using a first hydrocracking catalyst containing acid functions followed by a second catalyst containing zeolite beta, without intermediate separation of either gas or liquid between the two catalytic zones, as described in US Pat. No. 7,749,373. Preferably, in this case the second catalyst contains zeolite beta with an SAR greater than 25, very preferably greater than 250. An example is shown: after pre-hydrotreatment of a vacuum distillate feedstock, with an SAR equal to 30, a sequence of first 75% by volume of a catalyst containing 10% by weight of zeolite Y in its support with a lattice parameter equal to 24.29 Å, followed by a catalyst containing 3% by weight of β in its support, said β having an SAR of 300, makes it possible to reduce the operating temperature by 4° C. and achieve a target conversion of 87%, compared to a loading carried out with only a catalyst supported on zeolite Y. Subsequently, an increase of 3.5% by weight is also achieved in the middle distillate yield, but this is entirely due to the increase in the yield in the light oil fraction, and the oil yield remains unchanged (its low-temperature properties also remain unchanged). In other words, the process utilizing this catalyst train, in addition to improving the yield of the light oil fraction, also improves the low-temperature properties of this light oil fraction in terms of pour point, but the process does not allow any improvement in the yield of the oil fraction obtained. The same is true for the low-temperature properties of the oil fraction, which, for the same amount of catalyst used, are identical to those obtained for a process using only a catalyst containing zeolite Y.

[0020] In order to particularly maximize the production of middle distillates and reduce the carbon footprint of the refining process, it may also prove advantageous to work with renewable feedstocks in addition to fossil feedstocks, which may result in a reduction in the carbon footprint. Among the renewable feedstocks, for example, nC, which after hydroprocessing generally have boiling points consistent with those of fossil gas oil fractions, 15 ~nC 18This refers to vegetable oils, animal fats, or used cooking oils, which yield hydrocarbons primarily composed of long, straight-chain paraffins. Nevertheless, these straight-chain paraffins impart poor low-temperature properties to diesel, which necessitates the isomerization of these compounds to achieve the required fuel specifications. Another advantageous solution is to convert these straight-chain paraffins by selective hydrocracking for direct incorporation into petroleum fractions. This also allows the introduction of renewable carbon into these fossil fractions. The production of biokerosene, also known as SAF ("Sustainable Aviation Fuel"), is particularly sought after for decarbonizing the aviation sector, both civil and military.

[0021] Therefore, in the context of reducing greenhouse gas emissions, refineries must increase the proportion of biofuels in fuels. Public authorities aim to promote the use of biofuels in transportation, not only for land transport (diesel and petroleum engines) but also for aviation. For example, the Ancre Roadmap (the French National Alliance for the Coordination of Energy Research), published in June 2018, assessed the French sector's potential for the production of biofuels for aviation, taking into account the maturity and development time of these industrial sectors. The adoption process thus follows the French goal of introducing aviation biofuels to 5% of France's total by 2030. Additionally, the French National Low Carbon Strategy (SNBC), revised in 2018, sets long-term guidance for aviation, aiming to replace traditional fossil fuels by 50% with biofuels by 2050. Therefore, biofuel production has been accelerating in recent years and will continue to increase significantly in the future.

[0022] Numerous patent applications describe the co-processing of renewable feedstocks with fossil-sourced fuels to produce either gas oil or petroleum fractions, or both, which fractions contain a portion of biogenic carbon.

[0023] For example, in the hydroprocessing method including co-processing, the introduction of a renewable lipid feedstock containing triglycerides with a petroleum fossil feedstock, a diesel fraction, is described in French Patent No. 2949475, European Patent No. 1693432, and European Patent No. 2046917. This introduction makes it possible to produce a renewable diesel fraction and incorporate it directly into the diesel oil pool obtained from fossil resources without investing in a dedicated hydroprocessing unit. The advantages of co-processing a triglyceride-containing feedstock with a fossil petroleum fraction compared to the processing of a pure lipid feedstock include, for example: - Polymerization limitations related to the thermal instability of renewable feedstocks, - Reduction of sulfur, nitrogen and aromatics content due to dilution effect; - Limitations on heat release associated with hydroprocessing of biological feedstocks; - reduction of the CO and CO2 content in the gaseous effluent: limiting the inhibitory effect of CO on catalytic activity and limiting the risk of corrosion in the presence of water and CO2; - increasing the solubility of hydrogen in the mixture to be treated, etc., as described in full detail in French patent no. 2 949 475.

[0024] The hydrotreating process makes it possible to produce essentially renewable gas oil fractions, i.e. fractions with an initial boiling point of 250°C or 280°C and a final boiling point ranging up to 340°C or 370°C, depending on the rate of introduction at the inlet of the process.

[0025] In addition to renewable diesel, the hydrocracking process makes it possible to produce lighter biogenic products such as biokerosene and bionaphtha.

[0026] The production of bio-kerosene (or SAF) is receiving increasing attention in comparison with the production of renewable diesel within the context of the energy transition. Meanwhile, the upgrading of biological feedstocks into bio-naphtha for the petrochemical industry (with the aim of producing olefins, BTX aromatics, polymers and cosmetics, etc.) is also attracting interest. Refiners are therefore increasingly interested in technological solutions that allow the introduction of bio-kerosene into fossil oil and the production of bio-naphtha for the petrochemical industry.

[0027] Inventions such as WO 2009 / 148909 describe that pure feedstocks containing triglycerides, such as palm oil and animal fats, can be converted over a series of hydrotreating (over a sulfided NiMo catalyst supported on alumina) and hydrocracking (over a Pt-PD catalyst supported on amorphous silica-alumina) steps for the production of bionaphtha in yields of up to 28 wt.%.

[0028] Patent application WO 2011 / 012439 describes that lipid feedstocks can be converted to n-paraffins and propane by hydrodeoxygenation and decarbonylation over conventional hydrotreating catalysts. These n-paraffins, including fossil naphtha, are then blended and injected into a steam cracking unit for the production of olefins, diolefins, and aromatics.

[0029] EP 2143777 describes a method for hydrocracking a feedstock consisting of a mixture of vacuum distillates and vegetable or animal fat feedstocks using a series of hydrotreating catalysts (NiMo / Al2O3 type), followed by a hydrocracking catalyst (NiMo / zeolite type), followed by a post-treatment catalyst (hydrodesulfurization type), which allows obtaining a diesel fuel with a very low sulfur content. The incorporation of biological feedstocks containing vacuum distillates according to this invention significantly increases the yield of diesel fuel, but unfortunately, this leads to a decrease in the yield of petroleum. For example, this document notes a 6% increase in the yield of diesel fuel, but also a decrease of more than 3% in the yield of petroleum fuel due to the addition of 10% by weight of soybean oil as a mixture with the vacuum distillate. On the other hand, the diesel fuel obtained has deteriorated low-temperature properties: its cloud point is 3°C higher than that of fossil diesel fuel obtained without the addition of soybean oil.

[0030] It is well known that under hydrotreating operating conditions, n-paraffins obtained from lipid feedstocks are hardly converted. Therefore, at the end of the process, the main products found are normal paraffins with the same or only one less carbon atom number than the starting carboxylic acid chains present in the triglycerides. Currently, the most abundant liquid feedstocks for biofuel production are rapeseed oil, soybean oil, palm oil, and their derivatives, as well as, to a lesser extent, used cooking oil and animal fats. These renewable feedstocks contain triglycerides with fatty chains containing 16 and 18 carbon atoms. Therefore, the main products obtained after hydrotreating are mainly normal paraffins containing 15 to 18 carbon atoms. Consequently, these biological feedstocks are found primarily in the gas oil fraction, i.e., fractions with initial and final boiling points in the range of 220 to 390 °C.

[0031] In this case, obtaining the biokerosene fraction requires a further selective hydrocracking step.

[0032] US Patent No. 8,039,682 describes a process for producing petroleum from renewable feedstocks, optionally by co-processing with fossil feedstocks, which comprises the steps of hydrotreating, hydrodeoxygenation, isomerization and selective hydrocracking in the presence of a multifunctional catalyst or series of catalysts, gas / liquid separation of the resulting eluates, followed by separation of the paraffinic eluate to produce a jet fuel eluate, a light naphtha eluate and an eluate heavier than jet fuel, and then recycling the eluate heavier than jet fuel into a reaction zone at a recycle / feedstock volume ratio of 0.1 to 8.

[0033] Finally, catalytic systems are available that are capable of hydroisomerizing and / or selective hydrocracking compounds of gas oil hydrocarbon fractions into lighter petroleum fractions, which would make it possible to refine large amounts of (bio)petroleum from a very wide range of feedstocks without modifying existing processes, although, to the applicant's knowledge and as highlighted by all of the previously reported examples, existing knowledge does not make it possible to carry out this type of transformation. [Prior art documents] [Patent documents]

[0034] [Patent Document 1] U.S. Patent No. 7,585,405 [Patent Document 2] International Publication No. 08085517 [Patent Document 3] International Publication No. 08085517 [Patent Document 4] U.S. Patent No. 7,749,373 [Patent Document 5] French Patent No. 2949475 [Patent Document 6] European Patent No. 1693432 [Patent Document 7] European Patent No. 2046917 [Patent Document 8] French Patent No. 2949475 [Patent Document 9] International Publication No. 2009 / 148909 [Patent Document 10] International Publication No. 2011 / 012439 [Patent Document 11] European Patent No. 2143777 [Patent Document 12] U.S. Patent No. 8,039,682 Summary of the Invention [Means for solving the problem]

[0035] The applicant has discovered that the use of a process for refining middle distillates, which uses a fossil hydrocarbon feedstock as a mixture with a previously hydrotreated renewable feedstock and includes a hydrocracking step, and the use of a specific catalyst train, without modifying the process for hydrocracking the fossil feedstock, allows the production of high yields of petroleum and gas oil fractions, including the introduction of a high degree of biogenic carbon.

[0036] In particular, the use of a train of a first hydrocracking catalyst in a first catalytic zone comprising a large pore zeolite, preferably a large pore zeolite having at least one opening of at least 12 MR, and a metal of group VIB and a metal of group VIII according to the periodic table, followed by the use of a second catalyst in a second catalytic zone comprising a support comprising at least one metal of group VIB and / or at least one metal of group VIII of the periodic table and at least one zeolite of the BEA structure code, without any separation being carried out between the first and second catalytic zones, When the latter is used throughout the hydrocracking step, i.e., in 100% of the volume intended for the hydrocracking step, it makes it possible to improve the selectivity for the petroleum fractions compared to those obtained in a hydrocracking process using only the first catalyst, while at the same time producing low-temperature properties for the gas oil and the petroleum fractions that are improved compared to the use of any other catalyst or series of catalysts known to those skilled in the art.

[0037] The subject of the present invention is a process for producing middle distillates from at least one fossil hydrocarbon feedstock, in which at least 50% by weight of the compounds have an initial boiling point higher than 250 ° C and a final boiling point lower than 800 ° C, said fossil hydrocarbon feedstock can be new or used, and which is obtained by mixing, alone or in mixtures, at least one renewable feedstock selected from vegetable oils, algal oils, cooking oils and animal fats, and also by mixing, alone or in mixtures, feedstocks obtained from the reprocessing of biomass / plastics / tires and household waste. and co-processing the feed mixture, the process comprising hydrotreating the feed mixture in the presence of hydrogen and at least one hydrotreating catalyst, and hydrocracking at least some, preferably all, of the hydrotreated feed, the hydrocracking step being carried out at a temperature of 200°C to 480°C, a total pressure of 1 MPa to 25 MPa, a ratio of the volume of hydrogen to the volume of hydrocarbon feed of 80 to 5000 liters per liter, and a flow rate of 0.1 to 50 h, defined as the ratio of the volume of liquid hydrocarbon feed to the volume of catalyst introduced into the reactor. -1 and the hydrocracking step of the hydrotreated feedstock is carried out at a space velocity (HSV) of at least a) contacting, in a first catalytic zone, at least some, and preferably all, of the hydrotreated feedstock with at least one first catalyst comprising at least one Group VIB metal and / or at least one Group VIII metal of the periodic table, a support comprising at least one zeolite having at least a series of channels the openings of which are defined by rings of 12 oxygen atoms (12MR), and at least one binder; b) subsequently contacting in a second catalytic zone, without any intermediate separation step between the first and second catalytic zones, all of the effluent from step a) with a second catalyst comprising at least one metal from Group VIB and / or at least one metal from Group VIII of the Periodic Table, a support comprising at least one zeolite of the BEA structure code, and at least one binder.

[0038] An advantage of the present invention is that it provides a process for producing middle distillates for use in hydrocracking processes, where a particular catalyst series makes it possible to obtain high yields of petroleum, as well as low temperature properties of petroleum and gas oil fractions that are improved compared to those obtained in the prior art.

[0039] In particular, the advantage of the present invention is to provide a hydrocracking process which makes it possible to improve primarily the selectivity for petroleum fractions, while also obtaining low-temperature properties for petroleum and gas oil fractions which are improved compared to the use of prior art catalysts, or trains of such catalysts.

[0040] For the purposes of the present invention, the various embodiments presented may be used alone or in combination with each other, without being limited to combinations.

[0041] For purposes of the present invention, various ranges of parameters of 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.

[0042] In the following text, groups of chemical elements are given according to the CAS classification (CRC Handbook of Chemistry and Physics, published by CRC Press, editor in chief DRLide, 81st edition, 2000-2001). For example, group VIII according to the CAS classification corresponds to the metals of rows 8, 9 and 10 according to the new IUPAC classification, and group VIB corresponds to the metals of row 6.

[0043] In the text that follows, the expressions "between ... and ..." and "between ... and ..." are equivalent and mean that the limits of the interval are included in the range of values ​​stated. If this is not the case, or even if the limits are not included in the range stated, such clarification is provided by the present invention.

[0044] In this specification, the expression "greater than" is understood to mean strictly greater than and is represented by the symbol ">", and the expression "less than" is understood to mean strictly less than and is represented by the symbol "<".

[0045] The overall SiO2 / Al2O3 molar ratio of a zeolite is also referred to herein as the SAR, or silica-alumina ratio. The SiO2 / Al2O3 molar ratio is measured by X-ray fluorescence. DETAILED DESCRIPTION OF THE INVENTION

[0046] (Description of the embodiment) The present invention relates to a process for producing middle distillates from at least one fossil hydrocarbon feedstock, in which at least 50 wt. % of the compounds have an initial boiling point above 250°C and a final boiling point below 800°C, alone or in a mixture with at least one renewable feedstock selected from vegetable oils, algal oils and animal fats, which may be virgin or used as a mixture, and as a feedstock obtained from the reprocessing of plastics / tires and household waste, alone or in a mixture.

[0047] (Feed material) A wide variety of hydrocarbon feedstocks can be processed by the hydrocracking process according to the invention. The fossil hydrocarbon 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 250°C and a final boiling point below 800°C, preferably at least 60%, preferably at least 75%, more preferably at least 80% by weight of the compounds have an initial boiling point above 250°C and a final boiling point below 800°C.

[0048] The fossil hydrocarbon feedstock is advantageously chosen from gas oils obtained from catalytic cracking units or LCO (light cycle oil), atmospheric distillates, vacuum distillates obtained from direct distillation of crude oil or from conversion units such as FCC, coking, H-oil or visbreaking units, feedstocks derived from units for extracting aromatics from lube oil bases or obtained from solvent dewaxing of lube oil bases, fractions obtained from processes for fixed-bed or ebulate-bed desulfurization or hydroconversion of ATR (atmospheric residue) and / or VR (vacuum residue) and / or deasphalted oils. The above list is not limiting. The feedstock has a boiling point T5 greater than 200°C, preferably greater than 340°C, i.e. 95% by weight of the compounds present in the feedstock have a boiling point greater than 250°C, preferably greater than 340°C.

[0049] According to the invention, a fossil hydrocarbon feedstock is treated in the process according to the invention as a mixture comprising at least one renewable feedstock selected from vegetable oils, cooking oils, algal oils and animal fats, which may be virgin or used, alone or as a mixture, and feedstocks obtained from biomass / plastics / tires and household waste, alone or as a mixture.

[0050] The vegetable oils may advantageously be crude or wholly or partially refined and may be obtained from the following plants: rapeseed, sunflower, soybean, palm, palm kernel, olive, coconut, jatropha, but this list is not limiting. Algal oils or fish oils are also relevant. The animal fats are advantageously composed of residues from the food industry or chosen from blubber and fats originating from the catering industry.

[0051] These feedstocks contain essentially triglyceride-type chemical structures, known to those skilled in the art as fatty acid triesters, also known as free fatty acids. Thus, fatty acid triesters are composed of three fatty acid chains. These fatty acid chains, in triester form or free fatty acid form, have some unsaturation per chain, generally 0-3, referred to as the number of carbon-carbon double bonds per chain, but this can be particularly high for algae-derived oils, which generally have 5-6 unsaturations per chain.

[0052] More generally, the process according to the invention is capable of treating the above-mentioned feedstocks alone or as a mixture, whatever the proportions.

[0053] Preferably, the content of renewable feedstock in the feedstock mixture is between 0.5% and 40% by weight, preferably between 1% and 35% by weight, preferably between 2% and 30% by weight, more preferably between 5% and 25% by weight, relative to the total mass of the feedstock to be treated in the process according to the invention.

[0054] These feedstocks may optionally contain metals and / or nitrogen and / or oxygen and / or sulphur. Where appropriate, the process according to the invention optionally and advantageously comprises a liquid / gas separation step between the step of hydrotreating the feedstock and the hydrocracking step.

[0055] The nitrogen content of the feedstocks treated in the process according to the invention is generally greater than 500 ppm by weight, preferably between 500 and 10,000 ppm by weight, even more preferably between 700 and 4,000 ppm by weight, even more preferably between 1,000 and 4,000 ppm by weight. The sulphur content of the feedstocks 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.

[0056] 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, preferably less than 5 ppm by weight, preferably less than 3 ppm by weight, even more preferably less than 1 ppm by weight.

[0057] 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 300 ppm by weight.

[0058] Due to the presence of renewable feedstocks derived from biomass, the feedstocks treated in the process according to the invention may also contain oxygenated compounds, the content of which varies greatly depending on the feedstock converted in the process according to the invention, and is generally less than 50% by weight, preferably less than 15% by weight, very preferably less than 5% by weight, and even more preferably less than 2% by weight.

[0059] (Embodiment) According to the present invention, the method comprises a step of hydrotreating the feedstock in the presence of hydrogen and at least one hydrotreating catalyst, the hydrotreating step preferably being carried out at a temperature of 200-450°C under a pressure of 2-25 MPa for 0.1-6 hours. -1 The process is carried out at a space velocity of 100 to 5000 Nl / l with the amount of hydrogen introduced so that the volume ratio of liters of hydrogen to liters of hydrocarbon is 100 to 5000 Nl / l.

[0060] Operating conditions such as temperature, pressure, hydrogen recycle ratio and space velocity vary widely depending on the nature of the feedstock, the desired product quality and the available refinery equipment.

[0061] Preferably, the hydrotreating step according to the invention is carried out at a temperature of 250 to 450°C, very preferably 300 to 430°C, under a pressure of 5 to 20 MPa for 0.2 to 5 hours. -1 The process is carried out at a space velocity of 1000 rpm and with an amount of hydrogen introduced such that the volume ratio of liters of hydrogen to liters of hydrocarbon is 300-3000 Nl / l.

[0062] Conventional hydrotreating catalysts may advantageously be used in supported or unsupported form and preferably contain at least one amorphous support and at least one hydrotreating-dehydrotreating element selected from at least one non-noble metal element of groups VIB and VIII, usually at least one element of group VIB (especially from molybdenum or tungsten, taken alone or in a mixture) and at least one non-noble metal element of group VIII (especially from nickel or cobalt, taken alone or in a mixture).

[0063] Preferably, the amorphous support is alumina or silica-alumina.

[0064] Preferred catalysts are selected from catalysts NiMo, NiW, NiMoW or CoMo supported on alumina, and NiMo, NiW or NiMoW supported on silica-alumina.

[0065] The effluent obtained from the hydrotreating step and the portion entering the hydrocracking step a), preferably all of them, generally preferably contain a nitrogen content of less than 300 ppm by weight, less than 200 ppm by weight, preferably less than 100 ppm by weight, preferably less than 50 ppm by weight.

[0066] The process according to the invention may advantageously comprise a separation step between the hydrotreating and hydrocracking steps.

[0067] In one embodiment, the process according to the present invention does not include a separation step between the hydrotreating and hydrocracking steps.

[0068] According to the present invention, the method comprises a step of hydrocracking at least some, preferably all, of the hydrotreated feedstock, the hydrocracking step being carried out at a temperature of 200°C to 480°C, at a total pressure of 1 MPa to 25 MPa, with a ratio of the volume of hydrogen to the volume of hydrocarbon feedstock of 80 to 5000 liters per liter, and a flow rate of 0.1 to 50 h, defined as the ratio of the volume of liquid hydrocarbon feedstock to the volume of catalyst introduced into the reactor. -1 The process is carried out at a high space velocity (HSV).

[0069] Preferably, the hydrocracking step of the process according to the invention is carried out in the presence of hydrogen at a temperature of 250 to 480°C, preferably 320 to 450°C, very preferably 330 to 435°C, under a pressure of 2 to 25 MPa, preferably 3 to 20 MPa, for 0.1 to 20 hours. -1 , preferably 0.1 to 6 hours -1 , preferably 0.2 to 3 hours -1 The amount of hydrogen introduced is such that the volume ratio of liters of hydrogen to liters of hydrocarbon is 100 to 3000 l / l.

[0070] These operating conditions used in the process according to the invention generally make it possible to obtain conversions per pass to products with boiling points below 340°C, better still below 370°C, of ​​more than 15% by weight, even more preferably between 20% and 95% by weight.

[0071] In addition, the petroleum fractions produced by the process according to the invention have a crystallization vanishing point of less than -20° C., preferably less than -30° C., even more preferably less than -47° C. The gas oil fractions produced by the process have a cloud point of less than 15° C., preferably less than 5° C., and very preferably less than -5° C.

[0072] In accordance with the present invention, the step of hydrocracking at least some, and preferably all, of the hydrotreated feedstock comprises at least a) contacting the hydrotreated feedstock in a first catalytic zone with at least one first catalyst comprising at least one Group VIB metal and / or at least one Group VIII metal of the periodic table, a support comprising at least one zeolite having at least a series of channels the openings of which are defined by rings of 12 oxygen atoms (12MR), and at least one binder; b) subsequently contacting in a second catalytic zone, without any intermediate separation step between the first and second catalytic zones, all of the effluent from step a) with a second catalyst comprising at least one metal from Group VIB and / or at least one metal from Group VIII of the Periodic Table, a support comprising at least one zeolite of the BEA structure code, and at least one binder.

[0073] The first catalyst used in the first catalytic zone of hydrocracking step a) which preferably comprises at least one metal from group VIB and at least one metal from group VIII of the periodic table, taken alone or as a mixture, is preferably a sulfided phase catalyst.

[0074] Preferably, the metal of group VIB of the periodic table is selected from the group formed by tungsten and molybdenum, taken alone or in a mixture. According to a preferred embodiment, the metal of group VIB is molybdenum. According to a preferred embodiment, the metal of group VIB is tungsten.

[0075] Preferably, the non-noble metal of group VIII of the periodic table is selected from the group formed by cobalt and nickel, taken alone or in a mixture. According to a preferred embodiment, the non-noble metal of group VIII is cobalt. According to a preferred embodiment, the non-noble metal of group VIII is nickel.

[0076] Preferably, the catalyst comprises at least one metal of group VIB in combination with at least one non-noble metal of group VIII, the non-noble metal of group VIII being selected from the group formed by cobalt and nickel, taken alone or in admixture, and the metal of group VIB being selected from the group formed by tungsten and molybdenum, taken alone or in admixture.

[0077] In one embodiment, the following combinations of metals are used: nickel-molybdenum, cobalt-molybdenum, nickel-tungsten, cobalt-tungsten, and more advantageously also nickel-molybdenum and nickel-tungsten.

[0078] In the case where the catalyst comprises at least one metal of group VIB in combination with at least one non-noble metal of group VIII, the content of metal of group VIB, as oxide equivalent, is advantageously between 5% and 40% by weight, preferably between 10% and 35% by weight, preferably between 15% and 30% by weight, relative to the total mass of the catalyst, and the content of non-noble metal of group VIII, as oxide equivalent, is advantageously between 0.5% and 10% by weight, preferably between 1% and 8% by weight, very preferably between 1.5% and 6% by weight, relative to the total weight of the catalyst.

[0079] When the catalyst comprises at least one metal from Group VIB in combination with at least one non-noble metal from Group VIII, the catalyst is a sulfided catalyst.

[0080] For example, three metal combinations such as nickel-cobalt-molybdenum, nickel-molybdenum-tungsten, and nickel-cobalt-tungsten may also be used.

[0081] In one embodiment, the following combinations of metals are used: nickel-niobium-molybdenum, cobalt-niobium-molybdenum, nickel-niobium-tungsten, cobalt-niobium-tungsten, with the preferred combinations being nickel-niobium-molybdenum and cobalt-niobium-molybdenum. Four metal combinations, for example, nickel-cobalt-niobium-molybdenum, can also be used.

[0082] The catalyst may advantageously also contain at least one doping element selected from the group consisting of boron and phosphorus, preferably phosphorus.

[0083] The first catalyst is advantageously - 0.1% to 10% by weight, preferably 0.1% to 15% by weight, of at least one doping element selected from the group consisting of boron and phosphorus, preferably oxide of phosphorus, relative to the total mass of the catalyst, from 0% to 60% by weight, preferably from 0.1% to 50% by weight, and even more preferably from 0.1% to 40% by weight, of at least one element selected from group VB, preferably an oxide of niobium, relative to the total mass of the catalyst; - 0% to 20% by weight, preferably 0.1% to 15% by weight, and even more preferably 0.1% to 10% by weight of at least one element selected from group VIIA, preferably an oxide of fluorine, relative to the total mass of the catalyst.

[0084] According to the invention, the support of the first catalyst used in the first catalytic zone of hydrocracking step a) according to the invention comprises at least one zeolite having at least a series of channels whose openings are defined by rings of 12 oxygen atoms (12MR), as well as at least one binder.

[0085] The binder used in the support of the first catalyst, also called porous mineral matrix, advantageously consists of at least one refractory oxide, preferably selected from the group consisting of alumina, silica-alumina, clay, titanium oxide, boron oxide and zirconia, taken alone or in a mixture. Preferably, the binder is selected from alumina and silica-alumina, taken alone or in a mixture. More preferably, the binder is alumina. Advantageously, the alumina may be in any of its forms known to those skilled in the art. Highly preferably, the alumina is gamma alumina, for example boehmite.

[0086] Preferably, the support of the first catalyst comprises 20% to 99% by weight of binder, preferably 30% to 99% by weight, very preferably 50% to 95% by weight, very preferably 60% to 95% by weight, based on the total weight of the support.

[0087] The zeolite used in the support of the first catalyst is advantageously chosen from zeolites of FAU, BEA, ISV, IWR, IWW, MEI and UWY structural type, taken alone or in a mixture, and preferably chosen from zeolites of FAU and BEA structural type, taken alone or in a mixture.

[0088] In a preferred embodiment, the zeolite is selected from zeolite Y and zeolite beta taken alone or as a mixture, preferably the zeolite is zeolite Y, very preferably dealuminated zeolite USY.

[0089] Preferably, the support of the first catalyst comprises from 1% to 80% by weight, preferably from 1% to 70% by weight, even more preferably from 5% to 50% by weight, very preferably from 5% to 40% by weight of at least one zeolite, relative to the total mass of the support.

[0090] Preferably, the support of the first catalyst comprises: - from 1% to 80% by weight, preferably from 1% to 70% by weight, even more preferably from 5% to 50% by weight, and very preferably from 5% to 40% by weight of at least one zeolite relative to the total mass of the support, consisting of 20% to 99% by weight, preferentially 30% to 99% by weight, preferably 50% to 95% by weight, very preferably 60% to 95% by weight of at least said binder, relative to the total mass of said support;

[0091] In a preferred embodiment, the first catalyst comprises zeolite Y alone.

[0092] In another preferred embodiment, the first catalyst comprises zeolite USY and zeolite beta.

[0093] 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.

[0094] The zeolite Y used in the support of the first catalyst advantageously has an initial lattice parameter a of the unit cell of less than 24.55 Å, preferentially less than 24.45 Å, preferably less than 24.40 Å and even more preferably less than 24.35 Å. Preferably, the initial lattice parameter a of the unit cell is greater than 24.24 Å, preferably greater than 24.26 Å.

[0095] The zeolite Y used in the support of the first catalyst advantageously has a molecular weight of 550 to 1200 m as measured by nitrogen physisorption according to the BET method. 2 / g, preferentially 600-1100m 2 / g, preferably 650 to 1050 m 2 / g specific surface area.

[0096] According to a preferred embodiment of the invention, the zeolite Y suitable for use as the support of the catalyst a) used in the process according to the invention is advantageously prepared from a zeolite Y of the FAU structural type, preferably having an overall Si / Al atomic ratio of 2.3 to 2.8 after synthesis, advantageously in the form of NaY after synthesis. Said zeolite Y of the FAU structural type is advantageously subjected to one or more ion exchange steps before being subjected to a dealumination step. By the ion exchange(s), alkaline cations belonging to groups 1 and 2 of the periodic table present in the cation positions in the crudely synthesized zeolite Y of the FAU structural type are replaced with NH4 + Cation, preferably Na + cation to NH4 + It is possible for it to be partially or completely substituted with cations.

[0097] NH4 + The partial or total exchange of alkaline cations with cations is 80% to 100%, preferably 85% to 99.5%, more preferably 88% to 99% of the alkaline cations with NH4. + At the end of the ion exchange step(s), the alkaline cations initially present in the zeolite Y, preferably Na, are exchanged with the cations. + The residual amount of alkaline cations in the zeolite Y relative to the amount of cations, preferably Na + The residual amount of cations is advantageously between 0% and 20%, preferentially between 0.5% and 15%, preferably between 1.0% and 12%.

[0098] Preferably, this step involves removing the alkaline cations present in the zeolite, preferably Na + To at least partially remove the cations, multiple ion exchanges are carried out with a solution containing at least one ammonium salt selected from ammonium chlorate, sulfate, nitrate, phosphate or acetate, preferably ammonium nitrate NH4NO3.

[0099] Therefore, the alkaline cations in the zeolite Y at the end of one or more ion exchange steps, preferably Na+ The residual content of cations is preferably such that the alkaline cation / aluminium molar ratio, preferably the Na / Al molar ratio, is between 0:1 and 0.005:1, more preferably between 0:1 and 0.008:1.

[0100] The desired alkaline cation / aluminum ratio, preferably Na / Al, is determined by the NH4 + The NH4 concentration in the ion exchange solution can be obtained by adjusting the ion exchange temperature and the number of ion exchanges. + The concentration is advantageously between 0.01 and 12 mol l -1 between 1.00 and 10 mol l, preferably between 1.00 and 10 mol l -1 The temperature of the ion exchange step advantageously varies between 20 and 100°C, preferentially between 60 and 95°C, preferentially 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.

[0101] If appropriate, the zeolite Y obtained, preferably of the FAU structural type, may then be subjected to a dealumination step, which may advantageously be carried out by any method known to those skilled in the art. Preferably, dealumination is carried out by one or more acid attacks, optionally by heat treatment in the presence of steam (known as "steaming") and / or advantageously by treatment with an aqueous mineral or organic acid solution.

[0102] Preferably, the dealumination step involves a heat treatment followed by one or more acid attacks, or one or more acid attacks alone.

[0103] Preferably, the heat treatment to which the zeolite Y is subjected, optionally in the presence of steam, is carried out at a temperature between 200 and 900°C, preferably between 300 and 900°C, even more preferably between 400 and 750°C. The duration of the heat treatment is advantageously greater than or equal to 0.5 hours, preferably between 0.5 and 24 hours, very preferably between 1 and 12 hours. If the heat treatment is carried out in the presence of water, the volume percentage of steam during the heat treatment is advantageously between 5% and 100%, preferably between 20% and 100%, very preferably between 40% and 100%. The optionally present volume fraction not made up of steam is formed from air. The flow rate of steam and optionally formed gas from air is advantageously 0.2 l h of zeolite Y. -1 ·g -1 and 10l·h -1 ·g -1 is.

[0104] 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.

[0105] The heat treatment step in the presence of steam may advantageously be repeated as many times as necessary to obtain a Y zeolite suitable for use in the process according to the invention and suitable for implementing a support for a catalyst having a unit cell lattice parameter a of less than 24.55 Å, preferentially less than 24.45 Å, preferably less than 24.40 Å and even more preferably less than 24.35 Å.

[0106] The optional heat treatment step in the presence of steam is advantageously followed by an acid attack step which makes it possible to partially or completely remove the aluminate debris resulting from the heat treatment step in the presence of steam which may partially block the pores of the dealuminated zeolite, and thus makes it possible to unblock the pores of the dealuminated zeolite.

[0107] The acid attack may advantageously be carried out by suspending the zeolite Y, optionally previously subjected to a heat treatment, in an aqueous solution containing a mineral or organic acid. The mineral acid may be nitric acid, sulfuric 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 between 0.01 and 2.0 mol l -1 , preferably 0.5 to 10 mol l -1 The temperature of the acid attack step is advantageously between 20 and 100° C., preferentially between 60 and 95° C., preferably between 60 and 90° C., 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, preferably between 1 hour and 2 hours.

[0108] At the end of the heat treatment step(s), optionally in the presence of steam, and optionally the acid attack step, the process for modifying zeolite Y advantageously comprises the step of removing the alkaline cations, preferably Na, still present in the cation sites in the zeolite Y. + It comprises at least one partial or complete exchange step of cations, which is carried out in the same manner as the ion exchange step described above.

[0109] heat treatment step(s), optionally in the presence of steam, and optionally an acid attack step, and alkaline cations, preferably Na + At the end of the partial or complete cation exchange step, the process for modifying the zeolite Y may include a calcination step, which makes it possible to remove organic species present in the pores of the zeolite, for example those provided by the acid attack step or by the partial or complete alkaline cation exchange step. In addition, the calcination step makes it possible to produce a protonated form of the zeolite Y, which makes it possible to provide acidity for its use.

[0110] Calcination may advantageously be carried out in a muffle or tubular furnace, under dry air or in an inert atmosphere, in a swept or traversed bed. The calcination temperature is advantageously between 200 and 800° C., preferentially between 450 and 600° C., preferably between 500 and 550° C. The duration of the calcination hold is advantageously between 1 and 20 hours, preferentially between 6 and 15 hours, preferably between 8 and 12 hours.

[0111] The zeolite Y thus obtained has an initial lattice parameter a of the unit cell of less than 24.55 Å, preferentially less than 24.45 Å, preferably less than 24.40 Å, even more preferably less than 24.35 Å, and a lattice parameter a of 550-1200 m as measured by nitrogen physisorption according to the BET method. 2 / g, preferentially 600-1100m 2 / g, preferably 650 to 1050 m 2 / g specific surface area.

[0112] In a preferred embodiment, in addition to the zeolite USY, the support of the first catalyst also comprises zeolite beta, which zeolite beta has an overall SiO2 / Al2O3 molar ratio, or SAR, of between 10 and 100, preferentially between 20 and 50, preferably between 20 and 30. The zeolite beta used in the support of the first catalyst according to the invention advantageously has a SiO2 / Al2O3 molar ratio, or SAR, of between 400 and 800 m, as measured by nitrogen physisorption according to the BET method. 2 / g, preferentially 500-750m 2 / g, preferably 550 to 700m 2 / g specific surface area.

[0113] 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, U.S. Patent No. 3,308,069 describes the use of tetraethylammonium hydroxide, and U.S. Patent No. 5,139,759 describes the use of tetraethylammonium cations derived from tetraethylammonium halide compounds. Another standard method for preparing zeolite beta is presented in the book "Verified Synthesis of Zeolitic Materials."

[0114] In the preferred embodiment, where the support of the first catalyst comprises zeolite USY and zeolite beta, the first catalyst comprises: - 0.9% to 79.9% by weight, preferentially 1% to 70% by weight, preferably 5% to 50% by weight, and even more preferably 5% to 40% by weight of zeolite Y with an initial lattice parameter a0 of the unit cell of less than 24.55 Å, relative to the total weight of the support; - 0.1% to 6% by weight, preferentially 0.2% to 5% by weight, and preferably 0.5% to 5% by weight of zeolite beta relative to the total weight of the support, - comprising, and preferably consisting of, 20% to 99% by weight, preferentially 30% to 99% by weight, very preferably 50% to 95% by weight, and even more preferably 60% to 95% by weight of at least one binder, relative to the total weight of the support.

[0115] According to step b) of the process according to the invention, the process comprises contacting, in a second catalytic zone, all of the effluent obtained from step a), without any intermediate separation step between the first and second catalytic zones, with a second catalyst comprising at least one metal of group VIB and / or at least one metal of group VIII of the periodic table, a support comprising at least one zeolite of the BEA structure code, and at least one binder.

[0116] Preferably, the effluent obtained from step a) is passed to the second catalytic zone without an intermediate gas / liquid separation step.

[0117] The second catalyst used in the second catalytic zone of hydrocracking step b), which preferably comprises at least one metal from group VIB and at least one metal from group VIII of the periodic table, taken alone or as a mixture, is preferably a catalyst in sulfide form.

[0118] Preferably, the metal of group VIB of the periodic table is selected from the group formed by tungsten and molybdenum, taken alone or in a mixture. According to a preferred embodiment, the metal of group VIB is molybdenum. According to a preferred embodiment, the metal of group VIB is tungsten.

[0119] Preferably, the non-noble metal of group VIII of the periodic table is selected from the group formed by cobalt and nickel, taken alone or in a mixture. According to a preferred embodiment, the non-noble metal of group VIII is cobalt. According to a preferred embodiment, the non-noble metal of group VIII is nickel.

[0120] Preferably, the second catalyst comprises at least one metal of group VIB in combination with at least one non-noble metal of group VIII, the non-noble metal of group VIII being selected from the group formed by cobalt and nickel, taken alone or in admixture, and the metal of group VIB being selected from the group formed by tungsten and molybdenum, taken alone or in admixture.

[0121] In one embodiment, the following combinations of metals are used: nickel-molybdenum, cobalt-molybdenum, nickel-tungsten, cobalt-tungsten, with the preferred combinations being nickel-molybdenum and nickel-tungsten.

[0122] In the case where the second catalyst comprises at least one metal of group VIB in combination with at least one non-noble metal of group VIII, the content of metal of group VIB, as oxide equivalent, is advantageously between 5% and 40% by weight, preferably between 10% and 35% by weight, preferably between 15% and 30% by weight, relative to the total mass of the catalyst, and the content of non-noble metal of group VIII, as oxide equivalent, is advantageously between 0.5% and 10% by weight, preferably between 1% and 8% by weight, very preferably between 1.5% and 6% by weight, relative to the total weight of the catalyst.

[0123] When the second catalyst comprises at least one metal of Group VIB in combination with at least one non-noble metal of Group VIII, the catalyst is a sulfided catalyst.

[0124] For example, three metal combinations such as nickel-cobalt-molybdenum, nickel-molybdenum-tungsten, and nickel-cobalt-tungsten may also be used.

[0125] In one embodiment, the following combinations of metals are used: nickel-niobium-molybdenum, cobalt-niobium-molybdenum, nickel-niobium-tungsten, cobalt-niobium-tungsten, with the preferred combinations being nickel-niobium-molybdenum and cobalt-niobium-molybdenum. Four metal combinations, for example, nickel-cobalt-niobium-molybdenum, can also be used.

[0126] The catalyst may advantageously also contain at least one doping element selected from the group consisting of boron and phosphorus, preferably phosphorus.

[0127] The second catalyst is advantageously - 0.1% to 10% by weight, preferably 0.1% to 15% by weight, of at least one doping element selected from the group consisting of boron and phosphorus, preferably oxide of phosphorus, relative to the total mass of the catalyst, from 0% to 60% by weight, preferably from 0.1% to 50% by weight, and even more preferably from 0.1% to 40% by weight, of at least one element selected from group VB, preferably an oxide of niobium, relative to the total mass of the catalyst; - 0% to 20% by weight, preferably 0.1% to 15% by weight, and even more preferably 0.1% to 10% by weight of at least one element selected from group VIIA, preferably an oxide of fluorine, relative to the total mass of the catalyst.

[0128] According to the invention, the support of the second catalyst used in the second catalytic zone of the hydrocracking step b) according to the invention comprises at least one zeolite of the BEA structural code and at least one binder.

[0129] Preferably, the zeolite of the BEA structural code is zeolite beta, preferably zeolite beta having an overall silica to alumina molar ratio SAR of 10-300, preferentially 10-100, preferably 10-50, preferably 10-30, more preferably 10-25, even more preferably 12-24, even more preferably 15-24.

[0130] 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, U.S. Patent No. 3,308,069 describes the use of tetraethylammonium hydroxide, and U.S. Patent No. 5,139,759 describes the use of tetraethylammonium cations derived from tetraethylammonium halide compounds. Another standard method for preparing zeolite beta is shown in the book "Verified Synthesis of Zeolitic Materials" (Elsevier, 2001).

[0131] The zeolite beta used in the support of the second catalyst according to the invention advantageously has an average crystal size of less than 500 nm, preferably less than 350 nm. Advantageously, these crystals may optionally be in the form of agglomerates with a size ranging from 500 to 800 μm, preferably less than 25 μm. Furthermore, the zeolite beta used in the support of the catalyst b) according to the invention has a mean crystal size of less than 500 nm, preferably less than 350 nm, as measured by nitrogen physisorption according to the BET method. 2 / g, preferentially 500-750m 2 / g, preferably 550 to 720 m 2 / g, a specific surface area greater than 0.2 mL / g, preferentially greater than 0.40 mL / g as determined by BJH, and a mesopore volume of at least 120 m 2 / g, preferentially 140m 2 / g, very preferably at least 150m 2 / g, and even more preferably 150 to 300 m 2 / g. Finally, the ratio of the external surface area to the total BET surface area of ​​the zeolite beta contained in the support of catalyst b) is preferably between 15% and 50%, very preferably between 18 and 40%, even more preferably between 21% and 37%.

[0132] The binder used in the support of the second catalyst, also called porous mineral matrix, advantageously consists of at least one refractory oxide, preferably selected from the group consisting of alumina, silica-alumina, clay, titanium oxide, boron oxide and zirconia, taken alone or in a mixture. Preferably, the binder is selected from alumina and silica-alumina, taken alone or in a mixture. More preferably, the binder is alumina. Advantageously, the alumina may be in any of its forms known to those skilled in the art. Highly preferably, the alumina is gamma alumina, for example boehmite.

[0133] Preferably, the support of the second catalyst comprises 20% to 99% by weight of binder, preferably 30% to 99% by weight, very preferably 50% to 95% by weight, very preferably 60% to 95% by weight, based on the total weight of the support.

[0134] Preferably, the support of the second catalyst comprises: - from 1% to 70% by weight, preferentially from 1% to 50% by weight, even more preferably from 1.5% to 40% by weight, even more preferably from 2% to 30% by weight of at least one zeolite beta relative to the total mass of the support, comprising, and preferably consisting of, 30% to 99% by weight, preferentially 50% to 99% by weight, preferably 60% to 98% by weight, and very preferably 70% to 98% by weight of at least said binder, relative to the total mass of said support;

[0135] The second catalyst used in step b) of the process according to the invention may advantageously contain at least one other zeolite in its support. Where applicable, the other zeolite(s) are advantageously chosen from zeolites having at least one series of channels, the openings of which are defined by rings of 12 oxygen atoms (12MR), obtained alone or in a mixture, in particular from zeolites of the FAU, BEA, ISV, IWR, IWW, MEI, UWY, MFI and MTW structural types, or from zeolite IZM-2, preferably from zeolites of the FAU and BEA structural types, obtained alone or in a mixture. Preferably, the second catalyst may contain, in addition to a zeolite of the BEA structural code, another zeolite of the FAU structural code, preferably zeolite Y.

[0136] Preferably, the zeolite Y that may be used in the second catalyst has an initial lattice parameter a of the unit cell of less than 24.55 Å, preferentially less than 24.45 Å, preferably less than 24.40 Å, even more preferably less than 24.35 Å, and a pore size of 550 to 1200 m, as measured by nitrogen physisorption by the BET method. 2 / g, preferentially 600-1100m 2 / g, preferably 650 to 1050 m 2 / g specific surface area.

[0137] Preferably, the zeolite Y may be prepared according to the same method as described for the zeolite Y used in step a) of the process according to the invention.

[0138] In this case, the support of the second catalyst used in the process according to the invention comprises at least one zeolite of the BEA structural code, at least one zeolite Y, and at least one binder, said support preferably comprising: - from 1% to 50% by weight, preferentially from 1% to 30% by weight, even more preferably from 1.5% to 20% by weight, even more preferably from 2% to 30% by weight of at least one zeolite beta relative to the total mass of the support, - from 0.5% to 50% by weight, preferentially from 1% to 30% by weight, preferably from 1.5% to 10% by weight, and even more preferably from 2% to 5% by weight of at least one zeolite Y, relative to the total mass of the support; comprising, and preferably consisting of, 30% to 98.5% by weight, preferentially 40% to 98% by weight, preferably 70% to 97% by weight, and very preferably 65% ​​to 96% by weight of at least said binder, relative to the total mass of said support;

[0139] In this case, the second catalyst used in step b) of the process according to the invention is preferably different from the first catalyst used in step a) of the process.

[0140] In the hydrocracking step, the volume fraction of the first catalyst used in step a) relative to the total of the two catalysts used in step a) and step b) is preferably 50% to 95% by volume, preferably 60% to 95% by volume, very preferably 65% ​​to 90% by volume, and even more preferably 65% ​​to 85% by volume.

[0141] Preferably, the volume fraction of the second catalyst used in step b) relative to the total of the two catalysts used in steps a) and b) is 5% to 50% by volume, preferably 5% to 40% by volume, very preferably 10% to 35% by volume, and even more preferably 15% to 35% by volume.

[0142] The process for producing middle distillates according to the invention may advantageously be carried out according to any of the embodiments known in the prior art.

[0143] The process may advantageously be carried out in one or more stages, in one or more reactors, in fixed beds or evaporating beds, with or without a recycle, possibly after the hydrotreating step aimed at removing some sulfur, nitrogen or oxygen compounds present in the feedstock. If a recycle is carried out, it may take place at any point in the process, either in the hydrotreating step or in the first catalytic zone of hydrocracking step a).

[0144] In one embodiment of the "two-stage" hydrocracking process, the effluent obtained from step b) of the hydrocracking process is sent to a fractionating column in order to recover at least a middle fraction and at least a heavy fraction comprising unconverted compounds, said heavy fraction being sent either to a second step of hydrocracking, advantageously in the presence of hydrogen and a hydrocracking catalyst, or to hydrotreating step a).

[0145] (Preparation of the first and second catalysts according to the present invention) The first and second catalysts used in step a) and step b), respectively, of the hydrocracking step of the process according to the invention are advantageously prepared according to conventional methods used in the prior art.

[0146] In particular, the catalyst(s) - preparing a carrier, at least one porous mineral matrix, In the case of the first catalyst, at least one zeolite having at least a series of channels whose openings are defined by rings of 12 oxygen atoms (12MR); In the case of the second catalyst, mixing with at least one zeolite of the BEA structural code having an SAR of less than 25; forming said mixture; at least one hydrogenation-dehydrogenation element selected from the group formed by the elements of group VIB of the periodic table, preferably molybdenum and tungsten, the non-noble metal elements of group VIII of the periodic table, preferably cobalt, nickel, and mixtures thereof, preferably nickel and cobalt, and mixtures thereof, - introduction onto the support by adding at least one precursor of said element during shaping, in order to incorporate at least a portion of said element; and / or - preparing a support, comprising impregnating the support with at least one precursor of said element, - optionally prepared according to a preparation method which includes a step of drying and / or calcining, at the end of the preparation of the support, and / or a step of introducing at least one hydrogenation-dehydrogenation treatment element.

[0147] More specifically, the first catalyst is prepared by the following steps: - preparing a zeolite, preferably zeolite Y, having at least a series of channels whose openings are defined by rings of 12 oxygen atoms (12MR), according to methods known from the prior art, - mixing with a porous mineral matrix and shaping to obtain a carrier; - introducing at least one hydrogenation-dehydrogenation element onto the support by at least one of the following methods: (i) adding at least one precursor of said element during shaping in order to introduce at least a portion of said element; (ii) impregnating the support with at least one precursor of said hydrogenation-dehydrogenation element; Optionally, the product obtained at the end of each of the above preparation steps is dried and / or calcined according to a preparation method.

[0148] Likewise, more specifically, the second catalyst may be prepared by the following steps: - preparing a zeolite of the BEA structural code having an SAR of less than 25 according to the methods known from the prior art, - mixing with a porous mineral matrix and shaping to obtain a carrier; - introducing at least one hydrogenation-dehydrogenation element onto the support by at least one of the following methods: (i) adding at least one precursor of said element during shaping in order to introduce at least a portion of said element; (ii) impregnating the support with at least one precursor of said hydrogenation-dehydrogenation element; Optionally, the product obtained at the end of each of the above preparation steps is dried and / or calcined according to a preparation method.

[0149] Preferably, the porous mineral matrix is ​​derived from an alumina gel with a crystal size of 2 to 35 nm.

[0150] Preferably, the alumina gel used has a sulfur content of 0.001% to 1% by weight, preferably 0.001% to 0.40% by weight, very preferably 0.003% to 0.33% by weight, more preferably 0.005% to 0.25% by weight.

[0151] Preferably, the alumina gel used contains a sodium content of 0.001% to 1% by weight, preferably 0.001% to 0.15% by weight, very preferably 0.0015% to 0.10% by weight, more preferably 0.002% to 0.040% by weight.

[0152] The alumina gel used advantageously has a high degree of dispersibility which makes it possible to facilitate the shaping of said gel according to any of the methods known to those skilled in the art, in particular by kneading extrusion, by granulation, by the technique known as the oil drop technique.

[0153] The alumina has a specific surface area and pore distribution that is calibrated and adapted for use in a process for hydrocracking the hydrocarbon feedstock.

[0154] Preferably, the alumina is purely mesoporous, with no micropores present.

[0155] Preferably, the carrier is advantageously 100 m 2 / g and a mesopore volume of 0.5 mL / g or more, preferably 0.6 mL / g or more.

[0156] The mesopore volume of the support is defined as the volume contained in pores having an average diameter of 2 to 50 nm and is measured using mercury intrusion porosimetry.

[0157] Preferably, the alumina thus prepared and used in the present invention is a non-mesostructured alumina.

[0158] The carrier may be advantageously shaped by any technique known to those skilled in the art, for example by extrusion, by pelletizing, by oil drop congealing, by rotating plate granulation, or by any other method known to those skilled in the art.

[0159] The support is preferably formed into particles of various shapes and diameters. They are generally used in the form of cylindrical extrudates or multi-shaped extrudates, such as trilobes, tetralobes, or multi-shaped extrudates, in either a straight or twisted form, but may optionally be produced and used in the form of crushed powders, tablets, rings, beads, or wheels. However, the catalyst is advantageously in the form of extrudates having 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 may be cylindrical (which may or may not be hollow), twisted cylindrical, multi-lobed (e.g., two-lobed, three-lobed, four-lobed, or five-lobed), or toric. Any other shape may also be used.

[0160] One of the preferred shaping methods consists in co-kneading the zeolite with a binder in wet gel form, preferably alumina, for several tens of minutes, preferably 10 to 40 minutes, and then forcing the paste thus obtained through a die to form extrudates with a diameter preferably between 0.5 and 5 mm.

[0161] According to another preferred method of formation, the zeolite may be introduced during the synthesis of the porous mineral matrix. For example, according to this preferred embodiment of the invention, the zeolite, preferably zeolite Y, optionally β, is added during the synthesis of the porous mineral matrix, for example a silicoaluminous matrix, in which case the zeolite may be added to a mixture of alumina compounds in an acidic medium, advantageously containing a fully soluble silica compound.

[0162] According to the invention, the raw material obtained at the end of the shaping step is then subjected to a calcination step at a temperature of 500-1000°C for a duration of 2-10 hours, in the presence or absence of an air stream containing up to 60% by volume of water.

[0163] Preferably, the firing step is carried out at a temperature of 540°C to 850°C.

[0164] Preferably, the firing step is carried out for a duration of between 2 hours and 10 hours.

[0165] When the binder is specified as alumina gel, otherwise boehmite, the calcination step allows for the transition from boehmite to the final alumina.

[0166] The group VIB and / or group VIII elements may optionally be introduced during molding by adding at least one compound of said element to introduce at least a portion of said element.

[0167] The introduction of at least one hydrogenation-dehydrogenation treatment element may advantageously be accompanied by the introduction of at least one promoter element selected from phosphorus, boron, silicon and preferably phosphorus, optionally with the introduction of an element of group VIIA and / or VB. The shaped solid is optionally dried at a temperature between 60 and 250°C and optionally calcined at a temperature between 250 and 800°C for a duration between 30 minutes and 6 hours.

[0168] The step of introducing at least one hydrogenation-dehydrogenation element is advantageously carried out by methods known to those skilled in the art, and in particular by one or more operations of impregnating the shaped, calcined or dried support, preferably the 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.

[0169] Preferably, the introduction is carried out by dry impregnation with a solution containing precursors of the hydrogenation / dehydrogenation functions, i.e. precursors of group VIB and / or group VIII elements, optionally followed by a drying step, preferably without a calcination step.

[0170] When the catalyst of the present invention contains a non-noble Group VIII metal, the Group VIII metal is preferably introduced after the Group VIB metal, or at the same time as the latter, by one or more operations of impregnation of the shaped and calcined support.

[0171] The introduction of at least one hydrogenation-dehydrogenation treatment element may optionally be followed by drying at a temperature between 60 and 250°C, followed by calcination, optionally at a temperature between 250 and 800°C.

[0172] The sources of molybdenum and tungsten are advantageously selected from oxides and hydroxides, molybdic and tungstic acids and their salts, in particular 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. It is preferred to use oxides and ammonium salts such as ammonium molybdate, ammonium heptamolybdate and ammonium tungstate.

[0173] Sources of non-noble Group VIII metal elements that can be used are well known to those skilled in the art, for example, for non-noble metals, nitrates, sulfates, hydroxides, phosphates, halides such as chlorides, bromides and fluorides, carboxylates such as acetates and carbonates are used.

[0174] The preferred phosphorus source is orthophosphoric acid H3PO4, but its salts and esters, such as ammonium phosphate, are also suitable.Phosphorus can be introduced, for example, in the form of a mixture of phosphoric acid and nitrogen-containing basic organic compounds, such as aqueous ammonia, primary and secondary amines, cyclic amines, compounds of the pyridine and quinoline families, and compounds of the pyrrole family.Tungsten phosphate or tungsten molybdate can also be used.

[0175] 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, without limiting the scope of the present invention. These mixed compounds may be heteropolyanions. These compounds may be, for example, Anderson heteropolyanions.

[0176] The boron source may be boric acid, preferably orthoboric acid H3BO3, ammonium diborate or ammonium pentaborate, boron oxide, or boric acid ester. Boron can be introduced, for example, in the form of a mixture of boric acid, aqueous hydrogen peroxide, and nitrogen-containing basic organic compounds, such as aqueous ammonia, primary and secondary amines, cyclic amines, compounds of the pyridine and quinoline families, and compounds of the pyrrole family. Boron can be introduced, for example, by a solution of boric acid in a water / alcohol mixture.

[0177] Sources of Group VB elements that can be used are well known to those skilled in the art. For example, among niobium sources, oxides such as niobium pentoxide Nb2O5, niobate Nb2O5·H2O, niobium hydroxide and polyoxyniobic acid, niobium alkoxide of formula Nb(OR1)3, where R1 is an alkyl radical, niobium oxalate NbO(HC2O4)5, or ammonium niobate can be used. It is preferred to use niobium oxalate or ammonium niobate.

[0178] Sources of elements from Group VIIA that can be used are well known to those skilled in the art. For example, fluoride anions may be introduced in the form of hydrofluoric acid or its salts. These salts are formed with alkali metals, ammonium, or organic compounds. In the latter case, the salts are advantageously formed in the reaction mixture by the reaction between the organic compound and hydrofluoric acid. It is also possible to use hydrolyzable compounds that can release fluoride anions in water, such as ammonium silicofluoride (NH4)2SiF6, silicon tetrafluoride SiF4, or sodium silicofluoride Na2SiF6. Fluorine may be introduced, for example, by impregnation with an aqueous solution of hydrofluoric acid or ammonium fluoride.

[0179] Organic additives may optionally be added to any step in the preparation of the catalyst, preferably to the impregnation solution alone or together with the various metal precursors.

[0180] Before injecting the feedstock, the catalysts used in the process according to the invention are subjected to a sulfurization treatment in order to convert, at least in part, the metal species into sulfides before contacting them 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 known to those skilled in the art and already described in the literature. This treatment can be carried out simultaneously or successively for the two catalysts used in the process.

[0181] Conventional sulfurization processes, well known to those skilled in the art, consist of heating the catalyst in the presence of sulfide (neat or in a stream of, for example, a hydrogen / sulfide mixture) at temperatures between 150 and 800°C, preferably between 250 and 600°C, generally in a fluidized bed reaction zone.

[0182] The present invention is illustrated by the following examples, which are not intended to be limiting in any way.

[0183] (Example) Example 1: Preparation of support S1 containing zeolite Y and zeolite β The support S1 has a lattice parameter of 24.30 Å, a SiO2 / Al2O3 molar ratio (SAR) of 30, and a pH of 890 m as measured by nitrogen physisorption using the BET method in the presence of commercial boehmite (Pural SB3 from Sasol). 2 15 wt.% commercial zeolite USY with a specific surface area of ​​15 wt. / g, a SiO2 / Al2O3 molar ratio of 24, and a specific surface area of ​​670 m2 measured by nitrogen physisorption by the BET method. 2 The support was prepared by kneading extrusion of 5 wt.% of commercial zeolite beta per kg of zeolite β. The resulting extrudates were dried at 80°C and subsequently calcined at 600°C under moist air (5 wt.% water per kg of dry air). The calcined support contains, on a dry basis, 15 wt.% zeolite USY, 5 wt.% zeolite beta, and 80 wt.% alumina.

[0184] Example 2: Preparation of support S2 containing zeolite beta with an SAR of less than 25 The support S2 was prepared in the presence of commercial boehmite (Pural SB3 from Sasol) with a SiO2 / Al2O3 molar ratio of 24 and a solubility of 670 m as measured by nitrogen physisorption using the BET method. 2 The support was prepared by kneading extrusion of 5 wt. % of commercial zeolite beta, which has a specific surface area of ​​1000 nm / g. The resulting extrudates were dried at 80°C and subsequently calcined at 600°C under moist air (5 wt. % water per kg of dry air). The calcined support contains, on a dry basis, 5 wt. % zeolite beta and 95 wt. % alumina.

[0185] Example 3: Preparation of Support 3 Containing Zeolite Y The support S3 has a lattice parameter of 24.30 Å, a SiO2 / Al2O3 molar ratio of 30, and a solubility of 890 m as measured by nitrogen physisorption by the BET method in the presence of commercial boehmite (Pural SB3 from Sasol). 2 The support was prepared by kneading extrusion of 20 wt. % of commercial zeolite USY, which has a specific surface area of ​​0.15 g / g. The resulting extrudates were dried at 80°C and subsequently calcined at 600°C under moist air (5 wt. % water per kg of dry air). The calcined support contains, on a dry basis, 5 wt. % zeolite beta, 20 wt. % zeolite USY, and 80 wt. % alumina.

[0186] Example 4: Preparation of support S4 containing (possibly containing) zeolite beta with an SAR greater than 200 The support S2 was prepared in the presence of commercial boehmite (Pural SB3 from Sasol) with a SiO2 / Al2O3 molar ratio of 250 and a pH of 580 m as measured by nitrogen physisorption using the BET method. 2 The support was prepared by kneading extrusion of 5 wt. % of commercial zeolite beta, which has a specific surface area of ​​1000 nm / g. The resulting extrudates were dried at 80°C and subsequently calcined at 600°C under moist air (5 wt. % water per kg of dry air). The calcined support contains, on a dry basis, 5 wt. % zeolite beta and 95 wt. % alumina.

[0187] Example 5: Preparation of alumina support S5 The support S2 was prepared by kneading and extrusion of commercially available boehmite (Pural SB3 from Sasol). The extrudates were dried at 80°C and subsequently calcined at 600°C under moist air (5% by weight of water per kg of dry air). The calcined support is therefore zeolite-free.

[0188] Example 6: Preparation of catalyst: - C1: NiMoP(USY+β) supported on S1 -C2: NiMoP supported on S2 (β alone with SAR=24) -C3: NiMoP(USY+β) supported on S3 -C4: NiMoP supported on S4 (β with SAR=250 alone) -C5: NiMoP supported on zeolite-free S5 alumina Catalysts C1, C2, C3, and C4 were similarly prepared by dry impregnation of supports S1, S2, S3, and S4, respectively, using an aqueous solution containing elements such as Ni and Mo. The solution was obtained by dissolving the following precursors in water: nickel nitrate and ammonium heptamolybdate. The amount of precursor in the solution was adjusted as a function of the desired concentration on the final catalyst. After dry impregnation, the catalysts were dried under air at 120 °C.

[0189] Catalyst C5 was prepared in two steps. Catalyst C5_int was first prepared from support S5, similar to catalysts C1-C4, with different target contents and similar drying. This catalyst C5_int was then dry-impregnated with a solution of triethylene glycol (TEG) with a TEG / Mo molar ratio of 0.5 mol / mol and a volume composition of the solvent consisting of 50 v / v% water and 50 v / v% ethanol. After a final drying step at 100 °C, the final catalyst C5 was obtained.

[0190] The mass proportions in the catalyst are those shown in the table below:

[0191] [Table 1]

[0192] Example 7 (comparative): Hydrocracking of a mixture containing 83% by weight of a vacuum distillate and 17% by weight of animal fat over a train of hydrotreating catalysts followed by hydrocracking catalysts based on zeolite USY and zeolite beta.

[0193] Example 8 (comparative): Hydrocracking of a mixture containing 83% by weight of a vacuum distillate and 17% by weight of animal fat over a train of a hydrotreating catalyst followed by a hydrocracking catalyst based solely on zeolite USY.

[0194] Example 9 (according to): Hydrocracking a mixture containing 83 wt. % of a vacuum distillate and 17 wt. % of an animal fat over a series of a hydrotreating catalyst, followed by a first hydrocracking catalyst based on zeolite USY and zeolite beta, followed by a second hydrocracking catalyst based on zeolite beta with an SAR of 250. The volume fractions of the first and second hydrocracking catalysts are 75 vol. % and 25 vol. %, respectively.

[0195] Example 10 (according to): Hydrocracking a mixture containing 83 wt. % of a vacuum distillate and 17 wt. % of an animal fat over a series of hydrotreating catalysts, followed by a first hydrocracking catalyst based solely on zeolite USY, followed by a second hydrocracking catalyst based on zeolite beta with an SAR of 250. The volume ratios of the first to second hydrocracking catalysts are 25 vol. % and 75 vol. %, respectively.

[0196] Example 11 (according to): Hydrocracking a mixture containing 83 wt. % of a vacuum distillate and 17 wt. % of an animal fat over a series of hydrotreating catalysts, followed by a first hydrocracking catalyst based on zeolite USY and zeolite beta, followed by a second hydrocracking catalyst based on zeolite beta having an SAR of 24. The volume ratios of the first to second hydrocracking catalysts are 25 vol. % and 75 vol. %, respectively.

[0197] Example 12 (according to): Hydrocracking a mixture containing 83 wt. % of a vacuum distillate and 17 wt. % of an animal fat over a train of a hydrotreating catalyst, followed by a first hydrocracking catalyst based solely on zeolite USY, followed by a second hydrocracking catalyst based on zeolite β with an SAR of 24. The volume ratios of the first to second hydrocracking catalysts are 25 vol. % and 75 vol. %, respectively.

[0198] The feedstock characteristics for Examples 7-12, a mixture containing 83 wt. % vacuum distillate and 17 wt. % animal fat, are listed in Table 2.

[0199] The feedstock before being injected into the hydrocracking step is pretreated with a hydrotreating catalyst at a total pressure of 14 MPa and at a temperature and HSV pair that makes it possible to obtain an organic nitrogen content of 10 ppm at the hydrotreated feedstock, i.e., at the inlet of the hydrocracking catalyst bed.

[0200] All of the hydrotreating effluent from the hydrotreating section is sent directly to the hydrocracking section without any intermediate separation step. The temperature of the hydrocracking catalyst is controlled to achieve an overall conversion of the 370°C+ fraction of 86 wt%.

[0201] In Examples 9 to 12, the ratio of the first hydrocracking catalyst to the second hydrocracking catalyst is set to 75% by volume / 25% by volume, respectively, and there is no intermediate separation of the eluate between these two hydrocracking catalysts.

[0202] All of the examples are compared at the same total pressure of 14 MPa, the same total volume of catalyst, and the same feed flow rate.

[0203] The performance of the method is evaluated in terms of: Conversion activity through the weighted average temperature of both hydrocracking section 1 and section 2 required to achieve an overall conversion of 86% of the -370°C+ fraction, or WABT (weighted average bed temperature) (Table 3); Oil yields between -150 and 280°C (Table 2); - as well as low temperature flow properties (via the crystal vanishing point for petroleum oils and the cloud point for diesel oils) (Table 2).

[0204] The yields of the main products listed in Table 2 are calculated for the liquid feedstock, i.e., a mixture containing 83 wt. % vacuum distillate and 17 wt. % animal fat before the hydrotreating step. Note that the sum of the yields listed in Table 3 does not add up to 100% (but does add up to 98.7%) because the co-products (HS, NH, CO, CO, and water) and hydrogen consumption are not reported in Table 3, since they are produced during the hydrotreating step, which is the same for all systems compared, and does not vary from system to system.

[0205] (Properties of mixtures of vacuum distillate and animal fat)

[0206] [Table 2]

[0207] "SD" as simulated distillation Operating conditions and performance of the methods of Examples 7-12

[0208] [Table 3]

[0209] In Example 9 according to the invention, compared to Example 7, which uses only one hydrocracking catalyst comprising zeolite USY and zeolite beta throughout the catalytic zone, the use of a series of catalysts comprising zeolite USY and zeolite beta followed by a catalyst comprising zeolite beta with SAR=250 also allowed for an improvement in the low temperature properties of the petroleum and diesel fractions (a decrease in the crystallization vanishing point of the petroleum fraction and the cloud point of the diesel fraction of 5° C. and 9° C., respectively), as well as an improvement in the oil yield (+0.1%).

[0210] In Example 10 according to the invention, compared to Example 8, which uses only one train of hydrocracking catalysts containing only zeolite USY throughout the catalytic zone, the use of a series of catalysts containing only zeolite USY followed by a catalyst containing zeolite β with SAR=250 also allowed an improvement in the low temperature properties of the petroleum and diesel fractions (a decrease in the crystallization vanishing point of the petroleum fraction and the cloud point of the diesel fraction of 7° C. and 10° C., respectively), as well as an improvement in the oil yield (+0.2%).

[0211] In Example 11 (according to the invention), a series of supported hydrocracking catalysts comprising a mixture of zeolite USY and zeolite beta, followed by a supported catalyst (according to the invention) comprising zeolite beta with an SAR equal to 24, makes it possible to simultaneously obtain an improvement in the low-temperature properties of diesel and petroleum (a reduction in the crystallization vanishing point of the petroleum fraction of 4° C. and 8° C., respectively, in Example 11 according to the invention, and in the cloud point of the diesel fraction), as compared to Example 7, and to maximize the yield of petroleum (+1.3%).

[0212] In Example 12 (according to the invention), a series of supported hydrocracking catalysts comprising zeolite USY alone, followed by a catalyst supported on zeolite beta with a Si / Al ratio of 24, makes it possible to improve the oil yield (+0.6%) compared to Example 8. Likewise, the low-temperature properties of petroleum and diesel oils also improved compared to Example 8 (reduction in the crystallization vanishing point of the petroleum fraction and in the cloud point of the diesel fraction at 4° C. and 8° C., respectively), which shows that the invention also works with a first catalyst consisting only of USY without beta.

Claims

1. 1. A process for producing middle distillates from at least one fossil hydrocarbon feedstock, at least 50% by weight of which has an initial boiling point higher than 250°C and a final boiling point lower than 800°C, wherein the fossil hydrocarbon feedstock is co-processed as a feed mixture with at least one renewable feedstock selected from vegetable oils, algal oils, cooking oils and animal fats, which may be new or used, alone or as a mixture, and with feedstocks obtained from the reprocessing of biomass / plastics / tires and household waste, alone or as a mixture, the process comprising the steps of hydrotreating the feedstock mixture in the presence of hydrogen and at least one hydrotreating catalyst, and hydrocracking at least a part, preferably all, of the hydrotreated feedstock, wherein the hydrocracking step is carried out at a temperature of 200°C to 480°C, a total pressure of 1 MPa to 25 MPa, a ratio of the volume of hydrogen to the volume of hydrocarbon feedstock of 80 to 5000 liters / liter, and a flow rate defined by the ratio of the volume of liquid hydrocarbon feedstock to the volume of catalyst introduced into the reactor, for a period of 0.1 to 50 h. －１ and the step of hydrocracking the hydrotreated feedstock is carried out at a space velocity (HSV) of at least a) contacting in a first catalytic zone at least a portion, preferably all, of said hydrotreated feed mixture with at least one first catalyst comprising at least one Group VIB metal and / or at least one Group VIII metal of the periodic table, a support comprising at least one zeolite having at least a series of channels the openings of which are defined by rings of 12 oxygen atoms (12MR), and at least one binder; b) subsequently contacting in a second catalytic zone, without any intermediate separation step between said first and second catalytic zones, all of the effluent obtained from step a) with a second catalyst comprising at least one metal from Group VIB and / or at least one metal from Group VIII of the Periodic Table, a support comprising at least one zeolite of the BEA structure code, and at least one binder.

2. 2. The process according to claim 1, wherein the fossil hydrocarbon feedstock is selected from gas oils obtained from catalytic cracking units, atmospheric distillates, vacuum distillates obtained from direct distillation of crude oil or from conversion units such as FCC, coking, H-oil or visbreaking units, feedstocks derived from units for the extraction of aromatics from lube oil bases or obtained from the solvent dewaxing of lube oil bases, ATR (atmospheric residue) and / or VR (vacuum residue) and / or fractions obtained from processes for fixed bed or ebulate bed desulfurization or hydroconversion of deasphalted oils.

3. 3. The method according to claim 1 or 2, wherein the vegetable oil is raw or wholly or partially refined and is obtained from the following plants: rapeseed, sunflower, soybean, palm, palm kernel, olive, coconut, jatropha, and the animal fat is composed of residues from the food industry or is selected from blubber or fats originating from the catering industry.

4. 4. The process according to claim 1, wherein the zeolite used in the support of the first catalyst is selected from zeolites of FAU, BEA, ISV, IWR, IWW, MEI and UWY structural types, taken alone or in a mixture, and preferably selected from zeolites of FAU and BEA structural types, taken alone or in a mixture.

5. 5. The process according to claim 4, wherein the zeolite used in the support of the first catalyst is selected from zeolite Y and zeolite beta, taken alone or as a mixture, preferably the zeolite is zeolite Y, very preferably dealuminated zeolite USY.

6. 6. The process according to claim 5, wherein the zeolite Y used in the support of the first catalyst has an initial lattice parameter a of the unit cell of less than 24.55 Å, preferentially less than 24.45 Å, preferably less than 24.40 Å and even more preferably less than 24.35 Å.

7. 7. The process according to any one of claims 1 to 6, wherein the zeolite of BEA structure code used in the support of the second catalyst is zeolite beta, preferably having a SiO2 / Al2O3 molar ratio or SAR between 10 and 300, preferentially between 10 and 100, preferably between 10 and 50, preferably between 10 and 30, more preferably between 10 and 25, even more preferably between 12 and 24, still more preferably between 15 and 24.

8. 8. The process according to claim 7, wherein the second catalyst used in step b) is chosen from zeolites having at least a series of channels whose openings are defined by rings of 12 oxygen atoms (12MR), obtained alone or as a mixture, and preferably chosen from zeolites of FAU, BEA, ISV, IWR, IWW, MEI, UWY, MFI and MTW structural types, or zeolite IZM-2, and may contain at least one other zeolite chosen from zeolites of FAU and BEA structural types, obtained alone or as a mixture.

9. 9. The process according to any one of claims 1 to 8, wherein the volume fraction of the first catalyst used in step a) of the hydrocracking step relative to the total of the two catalysts used in step a) and step b) is preferably 50% to 95% by volume, preferably 60% to 95% by volume, very preferably 65% ​​to 90% by volume, even more preferably 65% ​​to 85% by volume.

10. 10. The method according to any one of claims 1 to 9, wherein the volume fraction of the second catalyst used in step b) relative to the total of the two catalysts used in steps a) and b) is between 5% and 50% by volume, preferably between 5% and 40% by volume, very preferably between 10% and 35% by volume, and even more preferably between 15% and 35% by volume.

11. 11. The process according to any one of claims 1 to 10, wherein the effluent obtained from step b) of the hydrocracking step is sent to a fractionation column to recover at least a middle fraction and at least a heavy fraction comprising unconverted compounds, the heavy fraction being sent either to a second step of hydrocracking in the presence of hydrogen and a hydrocracking catalyst, or to hydrotreating step a).

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