WO2009144412A2

WO2009144412A2 - Method for producing medium distillates by hydrocracking of charges arising from the fischer-tropsch process with an amorphous material catalyst

Info

Publication number: WO2009144412A2
Application number: PCT/FR2009/000556
Authority: WO
Inventors: Christophe Bouchy; Alexandra Chaumonnot
Original assignee: Ifp; Eni S.P.A.
Priority date: 2008-05-28
Filing date: 2009-05-13
Publication date: 2009-12-03
Also published as: FR2931833B1; FR2931833A1; WO2009144412A3

Abstract

The invention relates to a method for producing medium distillates from a paraffinic charge produced by Fischer-Tropsch synthesis, implementing a hydrocracking/hydroisomerization catalyst containing at least one hydro-dehydrogenating metal selected from the group of metals of periodic classification Group VIB and Group VIII and a substrate formed from at least one amorphous material containing silicon having hierarchical and organized porosity, consisting of at least two elementary spherical particles, each of said particles including a mesostructured silicon oxide matrix having a mesopore diameter of 1.5 to 30 nm and having amorphous microporous walls of a thickness of 1.5 to 50 nm, said elementary spherical particles having a maximum diameter of 200 microns.

Description

PROCESS FOR THE PRODUCTION OF MEDIUM DISTILLATES BY HYDROCRACKING FISCHER-TROPSCH PROCESS CHARGES WITH A CATALYST BASED ON AMORPHOUS MATERIAL

The present invention relates to a method for producing middle distillates from a paraffinic feedstock produced by Fischer-Tropsch synthesis, using a hydrocracking / hydroisomerization catalyst comprising at least one hydro-dehydrogenating metal chosen from the group formed by the Group VIB and Group VIII metals of the Periodic Table and a support consisting of at least one amorphous material comprising structured hierarchical porosity silicon, consisting of at least two elementary spherical particles, each of said particles comprising a matrix based on mesostructured silicon oxide having a mesopore diameter of between 1.5 and 30 nm and having amorphous and microporous walls with a thickness of between 1.5 and 50 nm, said elementary spherical particles having a maximum diameter of 200 microns.

State of the art

In the Fischer Tropsch process, the synthesis gas (CO + H ₂ ) is catalytically converted into oxygenates and essentially linear hydrocarbons in gaseous, liquid or solid form. These products are generally free of heteroatomic impurities such as, for example, sulfur, nitrogen or metals. They also contain practically little or no aromatics, naphthenes and more generally cycles especially in the case of the use of cobalt catalysts. On the other hand, they may have a significant content of oxygenated products which, expressed by weight of oxygen, is generally less than about 5% by weight and also an unsaturated content (olefinic products in general) generally less than 10% by weight. . However, these products, mainly made of normal paraffins, can not be used as such, in particular because of their cold-holding properties that are not very compatible with the usual uses of petroleum fractions. For example, the pour point of a linear hydrocarbon containing 20 carbon atoms per molecule (boiling point equal to about 340 ^° C., that is often included in the middle distillates cut) is + 37 ^° C. about which makes its use impossible, the specification being -15 ° C for diesel.

Starting charges intended to be treated in a gasification unit producing a gas consisting essentially of carbon monoxide and hydrogen, known to those skilled in the art as synthesis gas, said synthesis gas then making it possible to recompose a set of hydrocarbon cuts using the Fischer Tropsch process may be derived from renewable sources such as, for example, lignocellulosic type feedstocks, such as wood or straw waste. Products lignocellulosics are mainly formed of lignins and cellulose. The impurities contained in this type of lignocellulosic biomass feedstock are essentially solid impurities, metals in particular alkaline (Na, K), and sulfur compounds, as well as chlorinated and nitrogenous compounds.

The feedstocks may also be derived from renewable sources, such as oils and fats of plant or animal origin, or mixtures of such fillers, containing triglycerides and / or fatty acids and / or esters. Among the possible vegetable oils, they can be raw or refined, wholly or in part, and derived from the following plants: rapeseed, sunflower, soybean, palm, palm kernel, olive, coconut, jatropha this list is not limiting. Algae or fish oils are also relevant. Among the possible fats, there may be mentioned all animal fats such as bacon or fats consisting of residues from the food industry or from the food service industries. The charges thus defined contain triglyceride and / or fatty acid structures, whose fatty chains contain a number of carbon atoms of between 8 and 25.

Starting charges intended to be treated in a gasification unit producing a gas consisting essentially of carbon monoxide and hydrogen, known to those skilled in the art as synthesis gas, said synthesis gas then making it possible to recompose a set of hydrocarbon cuts using the Fischer Tropsch process may also be derived from the finely ground coal and purified so as to contain a reduced ash concentration.

The hydrocarbons resulting from the Fischer-Tropsch process comprising predominantly n-paraffins must be converted into more valuable products such as, for example, diesel fuel or kerosene, which are obtained, for example, after catalytic hydroisomerisation reactions. All the catalysts currently used in hydroconversion and / or hydroisomerization are of the bifunctional type associating an acid function with a hydrogenating function. The acid function is provided by supports with large surface areas (generally 150 to 800 m ² g ^-1 ) with surface acidity, such as halogenated aluminas (chlorinated or fluorinated in particular), phosphorus aluminas, combinations of boron and aluminum, silica-aluminas and silica aluminas. The hydrogenating function is provided either by one or more metals of group VIII of the periodic table of the elements, such as the elements iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium and platinum, or by a combination of at least one Group VI metal such as chromium, molybdenum and tungsten and at least one Group VIII metal. The balance between the two functions, acid and hydrogen, is the fundamental parameter that governs the activity and the selectivity of the catalyst. A weak acidic function and a strong hydrogenating function give catalysts which are not very active and selective towards isomerization whereas a strong acid function and a low hydrogenating function give very active and cracking-selective catalysts. A third possibility is to use a strong acid function and a strong hydrogenating function to obtain a very active catalyst but also very selective towards isomerization. It is therefore possible, by judiciously choosing each of the functions to adjust the activity / selectivity couple of the catalyst. Conventional catalysts for catalytic hydrocracking are for the most part constituted by weakly acidic supports, such as silica-aluminas or siliceous aluminas, for example. These systems are more particularly used to produce middle distillates of very good quality. Many of the hydrocracking market catalysts are based on Group VIII metal silica-alumina. These systems have a very good selectivity in middle distillates, and the products formed are of good quality (US 6,733,657). The disadvantage of all these silica-alumina catalyst systems is, as mentioned, their low activity. On the other hand, catalyst systems based on zeolite (in particular zeolite USY or beta) are very active for the hydrocracking reaction but are not very selective.

In the quest for new aluminosilicate materials, so-called "mesostructured" materials, discovered in the early 90s, represent an attractive alternative (GJ AA Soler-lllia, C. Sanchez, B. Lebeau, J. Patarin, Chem Rev. , 2002, 102, 4093). Indeed, thanks to so-called "soft chemistry" synthesis methods, amorphous mesoporous materials whose size and pore morphology are controlled have been obtained. These mesostructured materials are thus generated at low temperature by the coexistence in aqueous solution or in polar solvents of inorganic precursors with structuring agents, generally molecular or supramolecular, ionic or neutral surfactants. The control of electrostatic or hydrogen bonding interactions between the inorganic precursors and the structuring agent together with hydrolysis / condensation reactions of the inorganic precursor leads to a cooperative assembly of the organic and inorganic phases generating micellar aggregates of uniformly sized surfactants. and controlled within an inorganic matrix. This phenomenon of cooperative self-assembly, governed inter alia by the concentration of structuring agent, can be induced by progressive evaporation of a reagent solution whose concentration of agent structurant is less than the critical micelle concentration, which can lead for example to the formation of a mesostructured powder after atomization of the solution (aerosol technique). The release of the porosity is then obtained by removing the surfactant, which is conventionally carried out by chemical extraction processes or by heat treatment. Depending on the nature of the inorganic precursors and the structuring agent used as well as the operating conditions imposed, several families of mesostructured materials have been developed. For example, the M41S family initially developed by Mobil (JS Beck, JC Vartuli, WJ Roth, ME Leonowicz, CT Kresge, KD Schmitt, CT-W Chu, DH Oison, EW Sheppard, SB McCullen, JB Higgins, J. L Schlenker, J. Am Chem Soc, 1992, 114, 27, 10834), consisting of mesoporous materials obtained via the use of ionic surfactants such as quaternary ammonium salts, having a generally hexagonal, cubic or lamellar structure, Pores of uniform size in a range of 1.5 to 10 nm and amorphous walls of thickness of the order of 1 to 2 nm has been extensively studied. Similarly, the use of amphiphilic block-type macromolecular structuring agents has led to the development of the family of materials called SBA, these solids being characterized by a generally hexagonal, cubic or lamellar structure, large pores uniform in a range of 4 to 50 nm and amorphous walls of thickness in a range of 3 to 7 nm. However, it has been shown that, although having particularly interesting textural and structural properties (in particular for the treatment of heavy loads), the mesostructured aluminosilicate materials thus obtained developed a catalytic activity which was in all respects similar to that of their porous counterparts. unorganized (D. Zaho, J. Feng, Q. Huo, N. Melosh, GH Fredrickson, BF Chmelke, GD Stucky, Science, 1998, 279, 548, Y.-H. Yue, A. Gideon, J.- L. Bonardet, Espinose JB, Melosh N., Fraissard J., Surf Stud, ScL Catal., 2000, 129, 209). Numerous studies have therefore been undertaken with the aim of developing materials having a zeolite microporosity and a mesostructured porosity so as to simultaneously benefit from the zeolite-specific catalytic properties and from the catalytic and especially textural properties of the organized mesoporous phase.

A large number of synthetic techniques making it possible to generate materials having this bi-porosity have thus been listed in the literature (US 6,669,924, Z. Zhang, Y. Han, F. Xiao, S. Qiu, L Zhu, R Wang, Y. Yu, Z. Zhang, Zou B., Y. Wang, Sun H., Zhao D, Y. Wei, J. Am Chem Soc, 2001, 123, 5014 A. Karlsson, M. Stock, R. Schmidt, Micropor, Mesopor, Mater., 1999, 27, 181, P. Prokesova, S. Mintova, J. Cejka, T. Bein, Micropor. Mesopor. Mater., 2003, 64, 165; DT On, S. Kaliaguine, Angew. Chem. Int. Ed., 2002, 41, 1036). From an experimental point of view, contrary to the "aerosol" technique mentioned above, the aluminosilicate materials with hierarchical porosity thus defined are not obtained by a progressive concentration of inorganic precursors and (s) the agent (s). ) structuring (s) within the solution where they are present but are conventionally obtained by direct precipitation in an aqueous solution or in polar solvents by varying the value of the critical micelle concentration of the structuring agent. In addition, the synthesis of these materials obtained by precipitation requires a curing step in an autoclave and a filtration step of the generated suspension. The elementary particles usually obtained do not have a regular shape and are generally characterized by a size generally ranging between 200 and 500 nm and sometimes more.

By attempting to develop hydrocracking and paraffinic charge hydroisomerization catalysts such as Fischer-Tropsch synthesis feeds, the Applicant has discovered a process for producing middle distillates from a paraffinic feedstock produced by synthesis. Fischer-Tropsch, using a novel hydrocracking / hydroisomerization catalyst comprising at least one hydrodehydrogenating metal selected from the group consisting of Group VIB metals and Group VIII of the Periodic Table and a support comprising at least one material amorphous composition comprising structured hierarchical porosity silicon, said amorphous material comprising structured hierarchical porosity silicon consisting of at least two elementary spherical particles, each of said particles comprising a mesostructured silicon oxide matrix having a mesopore diameter between 1, 5 th at 30 nm and having amorphous and microporous walls with a thickness of between 1.5 and 50 nm, said elementary spherical particles having a maximum diameter of 200 microns.

Object of the invention

The present invention therefore relates to a process for the production of middle distillates. This process makes it possible to increase the amount of average distillates available by hydrocracking the heavier paraffinic compounds present in the outlet effluent of the Fischer-Tropsch unit, and which have boiling points higher than those of the kerosene cuts. and diesel, for example the fraction 370 ⁰ C ⁺ . More specifically, the invention relates to a method for producing middle distillates from a paraffinic feedstock produced by Fischer-Tropsch synthesis using a particular catalyst as defined in the description which follows.

Said method advantageously operates at a temperature of between 270 and 400 ^° C., a pressure of between 1 and 9 MPa, a space velocity of between 0.5 and 5 h ^-1 and a hydrogen flow rate adjusted to obtain a ratio of 400. to 1500 normal liters of hydrogen per liter of charge.

Preferably, the amorphous walls of said matrix based on silicon oxide consist entirely of proto-zeolite entities at the origin of the microporosity. These are species prepared from reagents used for the synthesis of zeolites or related solids, the preparation of said species has not been conducted to the stage of formation of crystallized zeolites. Thus, formulations resulting in any zeolite or related solid developing acidity properties can be used. As a result, said matrix based on silicon oxide further comprises at least one element X, the chemical nature of X being a function of the composition of said formulations used. Advantageously, X is the aluminum element. The present invention also relates to the preparation of the catalyst according to the invention.

Interest of the invention

The amorphous material comprising silicon having hierarchical and organized porosity constituting the catalyst according to the invention consisting of a mesostructured inorganic matrix, based on of silicon oxide, with amorphous and microporous walls, simultaneously exhibits the structural and textural properties of silicon oxide-based materials and, more precisely, mesostructured aluminosilicate materials, as well as properties of acid-base properties superior to the properties acido-basicity presented by the prior amorphous aluminosilicate materials, devoid of precursors of protozeolitic entities, and prepared according to synthesis protocols well known to those skilled in the art using inorganic precursors of silica and alumina. Moreover, the presence within the same spherical particle of micrometric or even nanometric size of organized mesopores in a microporous and amorphous inorganic matrix leads to a privileged access of the reagents and products of the reaction to the microporous sites during the use of the material as constituent element of the catalyst according to the invention in processes for the conversion of charges containing hydrocarbons, in particular accompanied by hydroisomerization of the long n-paraffins contained in said charges. In addition, the material according to the invention consists of spherical elementary particles, the diameter of these particles being at most equal to 200 μm, preferably less than 100 μm, advantageously varying from 50 nm to 20 μm, very advantageously to 50 nm. at 10 μm and even more advantageously from 50 nm to 3 μm. The limited size of these particles as well as their homogeneous spherical shape makes it possible to have a better diffusion of the reagents and the products of the reaction when the material is used as constitutive element of the catalyst according to the invention in processes for the conversion of fillers containing hydrocarbons.

The set of properties specific to the amorphous material comprising silicon with hierarchical and organized porosity thus induces catalytic properties specific to the catalyst according to the invention comprising said material when it is used in a process for producing middle distillates from a feedstock. paraffinic produced by Fischer-Tropsch synthesis. Indeed, while attempting to develop hydrocracking catalysts and hydroisomerization of paraffinic feedstocks resulting from the Fischer-Tropsch synthesis, the applicant has discovered a process for producing middle distillates from a paraffinic feedstock produced by Fischer synthesis. Tropsch, implementing a novel hydrocracking / hydroisomerization catalyst comprising at least one hydrodehydrogenating metal selected from the group consisting of Group VIB metals and Group VIII of the Periodic Table and a support comprising at least said amorphous material comprising silicon with hierarchical and organized porosity. Characterization techniques

The amorphous material comprising silicon having hierarchical and organized porosity constituting the catalyst according to the invention is characterized by several analysis techniques and in particular by X-ray diffraction at low angles (low-angle XRD), by nitrogen volumetry ( BET), Transmission Electron Microscopy (TEM) and Fluorescence X (FX).

Nitrogen volumetry, which corresponds to the physical adsorption of nitrogen molecules in the porosity of the material via a progressive increase in pressure at constant temperature, provides information on the textural characteristics (mesopore diameter, type of porosity, specific surface area). of the amorphous material present in the catalyst according to the invention. In particular, it provides access to the total value of the microporous and mesoporous volume of the amorphous material present in the catalyst according to the invention. The appearance of the nitrogen adsorption isotherm and of the hysteresis loop can provide information on the presence of the microporosity linked to the proto-zeolitic entities constituting the amorphous walls of the matrix of each of the spherical particles of the amorphous material present. in the catalyst according to the invention and on the nature of the mesoporosity. In the following description, the diameter of the mesospores ψ of the amorphous material present in the catalyst according to the invention corresponds to the mean diameter at the desorption of nitrogen defined as a diameter such that all the pores smaller than this diameter constitute 50 % of the pore volume (Vp) measured on the desorption branch of the nitrogen isotherm. The quantitative analysis of the microporosity of the amorphous material present in the catalyst according to the invention is carried out using methods "t" (method Lippens-De Boer, 1965) or "a _s " (method proposed by Sing) that correspond to transformations of the starting adsorption isotherm as described in "Adsorption bypowders and porous solids, Principles, methodology and applications" written by F. Rouquerol, J. Rouquerol and K. Sing, Academy Press, 1999. These methods allow access in particular to the value of the microporous volume characteristic of the microporosity of the amorphous material present in the catalyst according to the invention as well as to the specific surface of the sample. The reference solid used is LiChrospher Si-1000 silica (M. Jaroniec, M. Kruck, JP Olivier, Langmuir, 1999, 15, 5410). As regards the mesostructured matrix of the amorphous material present in the catalyst according to the invention, the difference between the value of the mesopore diameter φ and the correlation distance between mesopores d defined by DRX at the low angles as described below makes it possible to access the magnitude e where e = d - φ and is characteristic of the thickness of the amorphous walls of the mesostructured matrix of the amorphous material present in the catalyst according to the invention. Similarly, the curve V _ads (ml / g) = f (α _s ) obtained via the method O ₃ mentioned above is characteristic of the presence microporosity within the amorphous material present in the catalyst and leads to a micropore volume value in a range of 0.01 to 0.4 ml / g. The determination of the total microporous and mesoporous volume and the microporous volume as described above leads to a value of the mesoporous volume of the amorphous material present in the catalyst according to the invention in a range of 0.01 to 1 ml / g.

The technique of low-angle X-ray diffraction (values of the angle 2Θ between 0.5 and 3 °) makes it possible to characterize the periodicity at the nanoscale generated by the organized mesoporosity of the amorphous material present in the catalyst according to the invention. 'invention. In the following description, the X-ray analysis is carried out on powder with a diffractometer operating in reflection and equipped with a rear monochromator using copper radiation (wavelength of 1.5406 A). The peaks usually observed on the diffractograms corresponding to a given value of the angle 2Θ are associated with the inter-reticular distances d _(hk i) characteristic of the structural symmetry of the material, ((hkl) being the Miller indices of the reciprocal lattice) by the Bragg relation: 2 d _(hk i ₎ * sin (D) = n ^* D This indexation then allows the determination of the mesh parameters (abc) of the direct network, the value of these parameters being a function of the hexagonal, cubic structure , or vermicular obtained and characteristic of the periodic organization of the mesopores of the amorphous material present in the catalyst according to the invention. The Transmission Electron Microscopy (TEM) analysis is a technique also widely used to characterize the mesostructuration of the amorphous material present in the catalyst according to the invention. This allows the formation of an image of the studied solid, the observed contrasts being characteristic of the structural organization, the texture and the morphology of the particles observed, the resolution of the technique reaching a maximum of 0.2 nm. The analysis of the image also makes it possible to access the characteristic parameters d and φ of the amorphous material present in the catalyst according to the invention defined above.

The composition of the amorphous material present in the catalyst according to the invention can be determined by Fluorescence X (FX). The overall composition of the catalyst comprising at least one hydro-dehydrogenating metal selected from the group consisting of Group VIB metals and Group VIII of the Periodic Table and a support comprising at least one amorphous material comprising structured hierarchical porosity silicon can be determined by X-ray Fluorescence or Atomic Absorption depending on the nature of the constituent elements of the catalyst. In the case of a catalyst shaped in the form of beads, extruded for example, the distribution of the constituent elements of the catalysts within the beads, extruded, for example can be evaluated by means of elementary microanalysis by electronic probe (Castaing microprobe), or even for example the book "Physico-chemical analysis of industrial catalysts", Technip, 2001.

The measurement of the dispersion of Group VIB and Group VIII metals can also be carried out by any method known to those skilled in the art. By way of example, the dispersion of the noble metals of group VIII such as platinum can be carried out by the H ₂ / O ₂ titration method.

Finally, the analytical techniques mentioned for characterizing the amorphous material comprising hierarchized and organized porosity silicon can also be used to characterize the catalyst, in particular X-ray diffraction at low angles (X-ray at low angles), the volumetry at the lower end. Nitrogen (BET) and Transmission Electron Microscopy (TEM).

Detailed description of the invention

Said method advantageously operates at a temperature of between 270 and 400 ^° C. and preferably between 300 and 390 ^° C., a pressure of between 1 and 9 MPa and preferably between 2 and 8 MPa, a space velocity of between 0.5. and 5 h ^-1 and preferably between 0.8 and 3 h ^-1 and a hydrogen flow rate adjusted to obtain a ratio of 400 to 1500 normal liters of hydrogen per liter of filler and preferably a ratio of 600 and 1300 normal liters of hydrogen per liter of charge.

Hydrocracking and Hydroisomerization Catalyst Preferably, said hydrocracking / hydroisomerization catalyst comprises: 0.1 to 60%, preferably 0.1 to 50% and even more preferably 0.1 to 40% of at least one hydro-dehydrogenating metal selected from the group consisting of Group VIB metals and group VIII,

from 40 to 99.9% of a support comprising: 0 to 99% and preferably 2 to 98%, preferably 5 to 95% of at least one amorphous or poorly crystallized porous inorganic binder of the oxide type,

0.01 to 60%, preferably 0.05 to 40%, preferably 0.05 to 35% and very preferably 0.05 to 20% of an amorphous material comprising silicon with hierarchical and organized porosity. The percentages are expressed as percentages by weight relative to the total mass of the catalyst.

a) The hydro-dehydrogenating function.

According to the invention, the catalyst comprises at least one hydro-dehydrogenating metal selected from the group consisting of Group VIII metals and Group VIB metals, taken alone or in admixture.

Preferably, the group VIII elements are chosen from iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium or platinum, taken alone or as a mixture. According to a preferred embodiment, the elements of group VIII are the noble metals advantageously chosen from platinum and palladium.

According to another preferred embodiment, the group VIII elements are non-noble metals advantageously chosen from iron, cobalt and nickel. Preferably, the group VIB elements of the catalyst according to the present invention are selected from tungsten and molybdenum.

In the case where the hydrogenating function comprises a group VIII element and a group VIB element, the following metal combinations are preferred: nickel-molybdenum, cobalt-molybdenum, iron-molybdenum, iron-tungsten, nickel-tungsten, cobalt- tungsten, and very preferably: nickel-molybdenum, cobalt-molybdenum, nickel-tungsten. It is also possible to use combinations of three metals such as for example nickel-cobalt-molybdenum. When a combination of Group VI and Group VIII metals is used, the catalyst is then preferably used in a sulfurous form. The content of the hydro-dehydrogenating element of said catalyst according to the present invention chosen from the group formed by the metals of group VIB and non-noble group VIII is advantageously between 0.1 and 60% by weight relative to the total mass of said catalyst preferably between 0.1 and 50% by weight and very preferably between 0.1 and 40% by weight.

When the hydro-dehydrogenating element is a noble metal of group VIII, the catalyst preferably contains a noble metal content of between 0.05 and 10% by weight, even more preferably from 0.1 to 5% by weight relative to to the total mass of said catalyst.

b) The amorphous material comprising silicon with hierarchical and organized porosity. According to the invention, said amorphous material comprising structured hierarchical porosity silicon consists of at least two elementary spherical particles, each of said particles comprising a mesostructured silicon oxide-based matrix having a mesopore diameter included between 1.5 and 30 nm and having amorphous and microporous walls with a thickness of between 1.5 and 50 nm, said elementary spherical particles having a maximum diameter of 200 microns. The material present in the catalyst according to the invention is a hierarchically porous material in the fields of microporosity and mesoporosity and organized in the field of mesoporosity. For the purposes of the present invention, a material having a hierarchized and organized porosity means a material having a double porosity on the scale of each of said spherical particles: a mesoporosity, that is to say the presence of pores organized on the mesoporous scale having a uniform diameter of between 1.5 and 30 nm and preferably between 1.5 and 15 nm, distributed homogeneously and uniformly in each of said particles (mesostructuration) and a microporosity induced by the amorphous walls, the characteristics of this microporosity being a function of the proto-zeolitic entities constituting the amorphous walls of the matrix of each of the spherical particles of the hierarchized and organized porosity material present in the catalyst according to the invention. The microporosity is characterized by the presence of micropores, within said amorphous walls, having a diameter of less than 1.5 nm. The constituent support of the catalyst according to the invention also has one or more interparticle and / or intraparticular textural macroporosity (s). It should be noted that a porosity of microporous nature may also result from the interlaying of the surfactant, used during the preparation of the hierarchical and organized porosity material present in the catalyst according to the invention, with the inorganic wall at the level of the organic-inorganic interface developed during the mesostructuration of the inorganic component of said hierarchical and organized porosity material present in the catalyst according to the invention. Advantageously, none of the spherical particles constituting the material present in the catalyst according to the invention has macropores.

Preferably, the matrix based on silicon oxide each forming spherical particles of the hierarchical and organized porosity material present in the catalyst according to the invention has amorphous walls consisting entirely of protozeolithic entities, which are origin of the microporosity present within each of the spherical particles of the material present in the catalyst according to the invention. The proto-zeolitic entities are species prepared from reagents used for the synthesis of zeolites or related solids, the preparation of said species not having been conducted to the stage of the formation of crystallized zeolites. As a result, said small protozeolitic entities are not detected when they are characterized by X-ray diffraction at large angles. More specifically and in accordance with the invention, the proto-zeolite entities integrally and homogeneously constituting the amorphous microporous walls of the matrix of each of the spherical particles of the material present in the catalyst according to the invention are species resulting from the setting the presence of at least one structuring agent, at least one silicic precursor and at least one precursor of at least one element X, under variable conditions of time and temperature making it possible to obtain a clear solution, said species being able to serve as a initiates the synthesis of any zeolite or related solid developing acidity properties and in particular but not limited to those listed in "Atlas of zeolite framework types", δ " ¹ revised Edition, 2001, C. Baerlocher, WM Meier As a result, said silicon oxide matrix further comprises at least one element X, the chemical nature of which e X being a function of the chemical nature of said proto-zeolite entities used and may be non-exhaustively one of the following: aluminum, iron, germanium, boron and titanium. Advantageously, X is the aluminum element. In this case, the matrix of the material present in the catalyst according to the invention is an amorphous aluminosilicate, a precursor of a crystallized aluminosilicate material. This amorphous aluminosilicate has an Si / Al molar ratio equal to that of the solution of silicic and aluminic precursors leading to the formation of the proto-zeolitic entities integrally forming the amorphous and microporous walls of the matrix.

The term zeolite or related solid well known to those skilled in the art all crystalline microporous oxide solids whose atomic elements constituting the inorganic framework have a coordination IV. By definition, the name "zeolite" is attributed to said microporous silicic or aluminosilicic oxide solids. Similarly, the term "related solid" refers to all the oxide solids microporous crystallites whose atomic elements constituting the inorganic framework have an IV coordination, said microporous silicic or aluminosilicic oxide solids being excluded. Any zeolite or related solid having at least one trivalent atomic element at the origin of the presence of a negative charge of said framework and which can be compensated by a positive charge of protonic nature can develop acidity properties. In particular, aluminosilicate zeolites and related solids of silicoaluminophosphate type develop such properties. The proto-zeolite entities which constitute integrally the amorphous walls of the matrix of each of the particles of the material present in the catalyst according to the invention and at the origin of the microporosity thereof are preferably species for the primer of at least one zeolite selected from aluminosilicates ZSM-5, ZSM-48, ZSM-22, ZSM-23, ZBM-30, EU-1, EU-2, EU-11, Beta, zeolite A, Y, USY, VUSY, SDUSY, mordenite, NU-87, NU-88, NU-86, NU-85, IM-5, IM-12, IZM-2 and Ferrierite and / or at least one related solid selected from SAPO-11 silicoaluminophosphates and SAPO-34. Very preferably, the proto-zeolite entities integrally forming the amorphous and microporous walls of the matrix of each of the particles of the material present in the catalyst according to the invention are species for the primer of at least one zeolite chosen from the aluminosilicates of structural type MFI, BEA ₁ FAU, LTA and / or at least one related solid selected from silicoaluminophosphates of structural type AEL, CHA. The matrix based on silicon oxide, included in each of the spherical particles constituting the material present in the catalyst according to the invention, is mesostructured: it has mesopores having a uniform diameter of between 1.5 and 30 nm and preferably between 1, 5 and 15 nm, distributed homogeneously and evenly in each of the spherical particles. The material located between the mesopores of each of said spherical particles is micoporous and fully amorphous and forms walls, or walls, whose thickness is between 1 and 50 nm, preferably between 1 and 30 nm. The thickness of the walls corresponds to the distance separating a first mesopore from a second mesopore, the second mesopore being the pore closest to the first mesopore. The mesostructuration of the hierarchized and organized porosity material present in the catalyst according to the invention may be of the vermicular, cubic or hexagonal type depending on the nature of the surfactant used for the implementation of the material present in the catalyst according to the invention.

According to the invention, said elementary spherical particles constituting the hierarchical and organized porosity material present in the catalyst according to the invention have a maximum diameter equal to 200 microns, preferably less than 100 microns, advantageously between 50 nm and 20 μm, very advantageously between 50 nm and 10 μm, and even more advantageously between 50 nm and 3 μm. More specifically, they are present in the material present in the catalyst according to the invention in the form of aggregates. The hierarchical and organized porosity material present in the catalyst according to the invention advantageously has a specific surface area of between 100 and 1100 m ² / g and very advantageously between 200 and 1000 m ² / g.

The hierarchical and organized porosity material present in the catalyst according to the invention advantageously has a mesoporous volume measured by nitrogen volumetry of between 0.01 and 1 ml / g and a microporous volume measured by nitrogen volumetry between 0.01 and 0.4 ml / g.

The hierarchical and organized porosity material comprising silicon constituting the catalyst according to the invention is advantageously obtained according to the preparation process which comprises: a) the preparation of a clear solution containing the precursor elements of protozeolitic entities, namely at least one structuring agent, at least one silicic precursor and at least one precursor of at least one element X, X being advantageously aluminum; b) mixing in solution at least one surfactant and at least said clear solution obtained according to a) such that the ratio of the volumes of inorganic and organic materials is between 0.26 and 4; c) aerosol atomizing said solution obtained in step b) to lead to the formation of spherical droplets; d) drying said droplets and e) removing said structuring agent and said surfactant to obtain an amorphous material with hierarchical porosity in the range of microporosity and mesoporosity and organized in the range of mesoporosity. Subsequently this process and called "method of preparing the material hierarchized and organized porosity".

According to step a) of the method for preparing the material with hierarchical and organized porosity, the clear solution containing the precursor elements of protozeolitic entities, namely at least one structuring agent, at least one silicic precursor and at least one precursor of at least one element X, X being advantageously aluminum, is advantageously produced from operating protocols known to those skilled in the art. The silicic precursor used for the implementation of step a) of the method of preparation of the hierarchized and organized porosity material is advantageously chosen from the precursors of silicon oxide well known to those skilled in the art. In particular, it is advantageous to use a silicic precursor chosen from the silica precursors normally used in the synthesis of zeolites or related solids by For example solid powdered silica, silicic acid, colloidal silica, dissolved silica or tetraethoxysilane also called tetraethylorthosilicate (TEOS) are used. Preferably, the silicic precursor is TEOS.

The precursor of the element X, used for the implementation of step a) of the method for preparing the material with hierarchical and organized porosity, can advantageously be any compound comprising the element X and able to release this element in solution, especially in aqueous or aquo-organic solution, in reactive form. In the case where X is aluminum, the aluminum precursor is advantageously an inorganic aluminum salt of formula AIZ ₃ , Z being a halogen, a nitrate or a hydroxide. Preferably, Z is chlorine. The aluminum precursor may also be an aluminum sulphate of formula AI ₂ (SO ₄ ) ₃ . The aluminum precursor can also be an organometallic precursor of formula AI (OR) ₃ or R = ethyl, isopropyl, n-butyl, s-butyl (Al (O ⁵ C ₄ Hg) ₃ ) or t-butyl or a chelated precursor such as that aluminum acetylacetonate (AI (C ₅ H ₈ O ₂ ) ₃ ). Preferably, R is s-butyl. The aluminum precursor may also advantageously be sodium or ammonium aluminate or the alumina proper in one of its crystalline phases known to those skilled in the art (alpha, delta, teta, gamma), preferably under hydrated form or that can be hydrated.

It is also advantageous to use mixtures of the precursors mentioned above. Some or all of the aluminic and silicic precursors may optionally advantageously be added in the form of a single compound comprising both aluminum atoms and silicon atoms, for example an amorphous silica-alumina.

The structuring agent used for the implementation of step a) of the method for preparing the material with hierarchical and organized porosity may advantageously be ionic or neutral depending on the nature of the zeolite or related solid that would be obtained from said entities proto-zeolite. It is common to use the structuring agents of the following non-exhaustive list: nitrogenous organic cations such as tetrapropylammonium (TPA), elements of the family of alkalis (Cs, K, Na, etc.), ethercouronnes, diamines and any other structuring agent well known to those skilled in the art for the synthesis of zeolite or related solid.

The clear solution containing the precursor elements of protozeolitic entities is generally obtained according to step a) of the process for preparing the hierarchical and organized porosity material by preparing a reaction mixture containing at least one silicic precursor, at least one precursor of at least one element X, X being advantageously aluminum, and at least one structuring agent. The reaction mixture is either aqueous or aquo-organic, for example a water-alcohol mixture. It is preferred to working in a basic reaction medium during the various steps of the method of preparation of the hierarchical and organized porosity material in order to promote the development of the proto-zeolitic entities constituting the amorphous and microporous walls of the matrix of each of the particles of the material present in the catalyst according to the invention. The basicity of the solution is advantageously ensured by the basicity of the structuring agent used or by basification of the reaction mixture by the addition of a basic compound, for example an alkali metal hydroxide, preferably sodium hydroxide. . The reaction mixture may advantageously be subjected to hydrothermal conditions under autogenous pressure, optionally by adding a gas, for example nitrogen, at a temperature between room temperature and 200 ⁰ C, preferably between room temperature and 170 ⁰ C and still more preferably at a temperature which does not exceed 120 ^° C. until the formation of a clear solution containing the precursor elements of the proto-zeolitic entities constituting the amorphous and microporous walls of the matrix of each of the spherical particles of the material present in the catalyst according to the invention. According to a preferred procedure, the reaction mixture containing at least one structuring agent, at least one silicic precursor and at least one precursor of at least one element X, X being advantageously the aluminum is matured at room temperature so as to obtain a clear solution containing the precursor elements of proto-zeolithic entities capable of generating the formation of crystallized zeolite entities.

According to step a) of the process for preparing the material with hierarchical and organized porosity, the precursor elements of the proto-zeolitic entities present in the clear solution are advantageously synthesized according to operating protocols known to those skilled in the art. In particular, for a material according to the invention in which the matrix of each spherical particle is made up of protozeolite beta entities, a clear solution containing precursor elements of protozeolitic beta entities is advantageously produced from the operating protocol described. P. Prokesova, S. Mintova, J. Cejka, T. Bein et al., Micropor. Mesopor. Mater., 2003, 64, 165. For a material according to the invention in which the matrix of each spherical particle consists of proto-zeolitic entities of FAU type, a clear solution containing precursor elements of protozeolitic entities of type FAU is performed from the operating procedures described by Y. Liu, WZ Zhang, TJ Pinnavaia et al., J. Am. Chem. Soc., 2000, 122, 8791 and KR Kloetstra, HW Zandbergen, JC Jansen, H. vanBekkum, Microporous Mater., 1996, 6, 287. For a material according to the invention, the matrix of each spherical particle consists of entities Protozegic ZSM-5, a clear solution containing precursor elements of proto-zeolitic entities ZSM-5 is realized from the operating protocol described by AE Persson, BJ Schoeman, J. Sterte, J.-E. Otterstedt, Zeolites, 1995, 15, 611.

According to step b) of the method of preparation of the hierarchical and organized porosity material, the surfactant used is advantageously an ionic or nonionic surfactant or a mixture of both. Preferably, the ionic surfactant is chosen from anionic surfactants such as sulphates, for example sodium dodecyl sulphate (SDS). Preferably, the nonionic surfactant may be any copolymer having at least two parts of different polarities conferring properties of amphiphilic macromolecules. These copolymers may comprise at least one block that is part of the non-exhaustive list of the following families of polymers: fluorinated polymers (- [CH ₂ -CH ₂ -CH ₂ -CH ₂ -O-CO-RI-with R 1 = C ₄ F ₉ , C ₈ F ₁₇ , etc.), biological polymers such as polyamino acids (poly-lysine, alginates, etc.), dendrimers, polymers consisting of poly (alkylene oxide) chains. Any other amphiphilic copolymer known to a person skilled in the art may advantageously be used if it makes it possible to obtain a stable solution in step b) of the process for preparing the material with hierarchical and organized porosity, such as poly (styrene). for example (S. Fôrster, M. Antionnetti, Adv Mater., 1998, 10, 195, S. Fôrster, T. Plantenberg, Angew Chem Int.Ed, 2002, 41, 688; Colfen, Macromol, Rapid Commun., 2001, 22, 219). In the context of the present invention, a block copolymer consisting of poly (alkylene oxide) chains is preferably used. Said block copolymer is preferably a block copolymer having two, three or four blocks, each block consisting of a poly (alkylene oxide) chain. For a two-block copolymer, one of the blocks consists of a poly (alkylene oxide) chain of hydrophilic nature and the other block consists of a poly (alkylene oxide) chain of a nature hydrophobic. For a copolymer with three blocks, at least one of the blocks consists of a chain of poly (alkylene oxide) hydrophilic nature while at least one of the other blocks consists of a poly ( alkylene oxide) of hydrophobic nature. Preferably, in the case of a three-block copolymer, the hydrophilic poly (alkylene oxide) chains are poly (ethylene oxide) chains denoted (PEO) _x and (PEO) _Z and the Poly (alkylene oxide) chains of hydrophobic nature are chains of poly (propylene oxide) denoted (PPO) _y , poly (butylene oxide) chains, or mixed chains, each chain of which is a mixture of several alkylene oxide monomers. Very preferably, in the case of a three-block copolymer, it consists of two poly (ethylene oxide) chains and a poly (propylene oxide) chain. More specifically, use is made of a compound of formula (PEO) _x - (PPO) _y - (PEO) _z where x is between 5 and 300 and y is between 33 and 300 and z is between 5 and 300. Preferably , the values of x and z are identical. A compound is advantageously used in which x = 20, y = 70 and z = 20 (P123) and a compound in which x = 106, y = 70 and z = 106 (F127). Commercial nonionic surfactants known as Pluronic (BASF), Tetronic (BASF), Triton (Sigma), Tergitol (Union Carbide), Brij (Aldrich) are useful as nonionic surfactants in step b ) of the method for preparing the hierarchized and organized porosity material. For a four-block copolymer, two of the blocks consist of a poly (alkylene oxide) chain of hydrophilic nature and the other two blocks consist of a chain of poly (alkylene oxide) hydrophobic nature. The solution obtained at the end of step b) of the process for preparing the hierarchical and organized porosity material in which at least said surfactant and at least said clear solution obtained according to step a) are mixed can advantageously be acidic, neutral or basic. Preferably, said solution is basic and preferably has a pH greater than 9, this pH value being generally imposed by the pH of the clear solution containing the protozeolitic entity precursor elements obtained according to step a) of the process preparation of the material with hierarchical and organized porosity. The solution obtained at the end of step b) may be aqueous or may be a water-organic solvent mixture, the organic solvent preferably being a polar solvent, in particular an alcohol, preferably ethanol. The amount of organic compounds, that is to say in surfactant and structuring agent, present in the mixture according to step b) of the process for preparing the material with hierarchical and organized porosity is advantageously defined with respect to the quantity of material inorganic present in said mixture following the addition of the clear solution containing the precursor elements of proto-zeolitic entities obtained according to step a) of the method of preparation of the hierarchical and organized porosity material. The amount of inorganic material corresponds to the amount of material of the silicic precursor and at least one of the precursor of element X. The volume ratio Vi _n o _r ga _n _ic A / _u o _r e Ganiq in the mixture obtained after the implementation of step b) is such that the organic-inorganic binary system formed during the atomization step c) of the method for preparing the material with hierarchical and organized porosity undergoes a process of mesostructuring by self-assembly surfactant together with the hydrolysis / condensation reactions of the various inorganic precursors. Said volume ratio

OrganicOrganic / organic β is defined COITime SUI: OrganicOrganic / organic = (m _in org * Porg) / (m _O rg * Pinorg) Where nii _nor g is the final mass of the inorganic fraction in the form of condensed oxide (s) ) in the solid elementary particle obtained by atomization, m _org is the total mass of the nonvolatile organic fraction found in the solid elementary particle obtained by atomization, p _org and p _inor g are the densities respectively associated with the organic fractions. non-volatile and inorganic. In the context of the invention, when the element X is aluminum and for a simplification of the calculations (approximations valid for a large majority of nonvolatile organic fraction and for an inorganic fraction of the "aluminosilicate network" type), it is considered that that p _org = 1 and p _in o _r g = 2. In the context of the invention, m _in org generally corresponds to the mass of SiO ₂ added to that of the mass of AlO ₂ when X is aluminum, and m _org corresponds to the mass of the structuring agent, for example TPAOH, added with the mass of the surfactant, for example the surfactant F127. The polar solvent preferably ethanol, and water and sodium hydroxide, are not taken into account in the calculation of said ratio _n Vinorga iqueA / orgaπique- species comprising an element X, advantageously aluminum species, for the preparation of the material present in the catalyst according to the invention, after the implementation of said step b) are not taken into account for the calculation of the Vi _πor g _anic / V _or gaπic volume ratio defined above. According to the invention, the amount of organic matter and the amount of inorganic material in the mixture obtained after carrying out step b) is such that the ratio Vj _norg iqueA a _n / orga _n ic is in a range of 0.26 to 4 and preferably in a range of 0.30 to 2. In accordance with step b) of the method of preparation of the hierarchical and organized porosity material, the initial concentration of surfactant, introduced into the mixture , defined by C ₀ is such that C ₀ is less than or equal to c _mc , the parameter c _mc representing the critical micellar concentration well known to those skilled in the art, that is to say the concentration limit beyond which occurs the phenomenon of self-arrangement of the surfactant molecules in the solution obtained at the end of step b). Before atomization, the concentration of surfactant molecules of the solution obtained at the end of step b) of the method of preparation of the hierarchized and organized porosity material does not therefore lead to the formation of particular micellar phases. In a preferred implementation of the process according to the invention, the concentration C ₀ is lower than the c _mc , the ratio VinorganiqueA / organic is such that the composition of the binary system verifies the composition conditions for which a mechanism of mesostructuration occurs by cooperative self-assembly of the reagents (Vi _n o _r ga _n iqueA / o _r g _year _ics between 0.26 and 4, preferably between 0.3 and 2) and the solution referred to in step b) method of preparing the hierarchical and organized porosity material is a basic water-alcohol mixture.

The step of atomizing the mixture according to step c) of the method for preparing the material with hierarchical and organized porosity advantageously produces spherical droplets. The size distribution of these droplets is lognormal. The aerosol generator used here is a commercial model 9306A device supplied by TSI having an atomizer 6 jets. The atomization of the solution is carried out in a chamber into which a carrier gas, an O ₂ / N ₂ mixture (dry air), is sent under a pressure P equal to 0.15 MPa. According to step d) of the method of preparation of the hierarchized and organized porosity material, said droplets are dried. This drying is advantageously carried out by transporting said droplets via the carrier gas, the O ₂ / N ₂ mixture, in PVC tubes, which leads to the gradual evaporation of the solution, for example from the basic aqueous-organic solution. obtained during step b) of the process for preparing the material with hierarchical and organized porosity, and thus obtaining spherical elementary particles. This drying is advantageously perfect by a passage of said particles in a furnace whose temperature can be adjusted, the usual range of temperature ranging from 50 to 600 ⁰ C and preferably from 80 to 400 ⁰ C, the residence time of these particles in the oven being of the order of the second. The particles are then advantageously harvested on a filter. A pump placed at the end of the circuit promotes the routing of species in the aerosol experimental device. The drying of the droplets according to step d) of the method of preparation of the hierarchically and organically porous material is advantageously followed by a passage in an oven at a temperature of between 50 and 150 ° C.

In the particular case where the element X, used for the implementation of step a) of the method of preparation of the hierarchical and organized porosity material, is the aluminum element and where the sodium element is present in the solution obtained in accordance with step a) of the method of preparation of the hierarchical and organized porosity material via the use of sodium hydroxide and / or a soda structuring agent ensuring the basicity of said clear solution, it is preferred performing an additional ion exchange step for exchanging the Na ⁺ cation by the NH ₄ ⁺ cation between steps d) and e) of the method for preparing the hierarchized and organized porosity material. This exchange, which leads to the formation of protons H ⁺ after step e) of the method of preparation of the material with hierarchical and organized porosity in the preferred case where the removal of the structuring agent and the surfactant is carried out by calcination under air, is carried out according to operating protocols well known to those skilled in the art. One of the usual methods consists in suspending the dried solid particles from step d) of the method of preparation of the hierarchized and organized porosity material in an aqueous solution of ammonium nitrate. The assembly is then advantageously brought to reflux for a period of 1 to 6 hours. The particles are then advantageously recovered by filtration (centrifugation 9000 rpm), washed and then dried by passing in an oven at a temperature between 50 and 150 ° C. This ion exchange / washing / drying cycle can advantageously be repeated several times and preferably two more times. This exchange cycle may advantageously also be carried out after steps d) and e) of the method for preparing the material with hierarchical and organized porosity. Under these conditions, step e) is then advantageously reproduced after the last exchange cycle so as to generate the protons H ⁺ as explained above.

According to step e) of the method of preparation of the hierarchical and organized porosity material, the elimination of the structuring agent and the surfactant, in order to obtain the material present in the catalyst according to the invention with hierarchical porosity in the areas of microporosity and mesoporosity and organized in the field of mesoporosity, is advantageously carried out by chemical extraction processes or by heat treatment and preferably by calcination under air in a temperature range of 300 to 1000 ⁰ C and more specifically in a range of 400 to 600 ⁰ C for a period of 1 to 24 hours and preferably for a period of 2 to 12 hours. In the case where the solution referred to in step b) of the process for preparing the hierarchized and organized porosity material is a water-organic solvent mixture, preferably a basic one, it is essential during step b) of the method of preparing the material with a hierarchical and organized porosity that the surfactant concentration at the origin of the mesostructuration of the matrix is less than the critical micellar concentration and that the ratio Vj _noπ - _anιque / V _org anique is in a range of 0, 26 to 4 and preferably in a range of 0.30 to 2 so that the evaporation of said aqueous-organic solution, preferably basic, during step c) of the method for preparing the material with hierarchical porosity and organized by the aerosol technique induces a phenomenon of micellization or self-assembly leading to the mesostructuration of the matrix of the material present in the catalyst according to the invention. 'invention. When C ₀ <c _mc , the mesostructuration of the matrix of the material present in the catalyst according to the invention is consecutive to a progressive concentration, within each droplet, of the precursor elements of proto-zeolitic entities of the clear solution obtained at step a) of the method for preparing the hierarchical and organized porosity material and of at least one surfactant introduced during step b) of the method for preparing the hierarchical and organized porosity material, up to a concentration of surfactant c> c _mc resulting from evaporation of the aqueous-organic solution, preferably basic.

According to a first preferred embodiment of the process for preparing the hierarchically organized and organized porosity material, at least one precursor of at least one element X, X being advantageously aluminum, is introduced for the implementation of said step b) of the method for preparing the material with hierarchical and organized porosity. Thus, the mixture in solution of at least one surfactant and at least said clear solution obtained according to step a) of the process of the invention is carried out in the presence of at least one precursor of said element X, advantageously among the aluminum precursors, described above in the present description, for the implementation of said step a) of the method for preparing the material with hierarchical and organized porosity. According to said first preferred embodiment of the process for preparing the hierarchical and organized porosity material, the preparation of the clear solution according to step a) of the method for preparing the hierarchized and organized porosity material is carried out either in the presence or in the absence of at least one precursor of at least one element X. According to a second preferred embodiment of the preparation method of the invention, at least one precursor of at least one element X, X being advantageously aluminum , is introduced during the implementation of said step d) and / or said step e) of the method of preparation of the hierarchical and organized porosity material, in order to produce a surface modification of the material present in the catalyst according to the invention. According to said second preferred embodiment of the process for preparing the material with hierarchical and organized porosity, said precursor of at least one element X, advantageously the aluminic precursor, is introduced during the implementation of said step d) and / or said step e) by any surface modification technique well known to those skilled in the art such as the grafting of at least one precursor of at least one element X, the dry impregnation of at least one precursor at least one element X and the impregnation in excess of at least one precursor of at least one element X. Said precursor of at least one element X, advantageously an aluminum precursor, introduced during the implementation of said step d) and / or of said step e) of the method of preparation of the material with hierarchical porosity and organized by a surface modification technique, is chosen from the precursors of said element X, preferably one of the aluminum precursors, described above in the present description, for the implementation of said step a) of the method for preparing the hierarchized and organized porosity material. According to said second preferred embodiment of the process for preparing the hierarchical and organized porosity material, step a) of the method for preparing the hierarchical and organized porosity material is carried out in the presence or in the absence of at least one precursor at least one element X, advantageously an aluminum precursor, and step b) of the process for preparing the hierarchical and organized porosity material is carried out in the presence or in the absence of at least one precursor of at least one element X, advantageously an aluminum precursor. In accordance with the method for preparing the hierarchical and organized porosity material, said first preferred embodiment of the method for preparing the porous material hierarchical and organized and said second preferred embodiment of the method of preparation of the hierarchical and organized porosity material are only optional variants of the method of preparation of the hierarchized and organized porosity material. Also, when the mesostructured matrix of each of the spherical particles of the material present in the catalyst according to the invention comprises an element X, advantageously aluminum, said element X, advantageously aluminum, is introduced either during said step a) of the method of preparation of the hierarchical and organized porosity material for the preparation of said clear solution, either during said step b) in accordance with said first preferred embodiment of the method for preparing the hierarchically porous and organized material, or again during the course of said step d) and / or said step e) according to said second preferred embodiment of the process for preparing the hierarchically organized porous material. The element X, advantageously aluminum, can also be introduced, several times, during the implementation of several steps in all possible combinations of the embodiments described above. In particular, it is advantageous to introduce the aluminum during said step a) and said step b) or during said step a) and said step d) and / or said step e).

In the case where the element X is advantageously aluminum, the amorphous aluminosilicate obtained according to the method of preparation of the hierarchized and organized porosity material then has a Si / Al molar ratio defined from the amount of silicon element introduced during of step a) of the method of preparation of the hierarchical and organized porosity material and of the total quantity of aluminum element introduced into the step (s) of the method of preparation of the material with hierarchical porosity and organized according to the different modes of preferred embodiment described above. Under these conditions and preferably, the range of the Si / Al molar ratio of the material according to the invention is between 1 and 1000.

When said first preferred embodiment of the process for the preparation of the hierarchical and organized porosity material is applied, the quantities of organic and inorganic material to be introduced for the implementation of step b) are to be adjusted according to the amount of additional material element X, preferably aluminum, introduced in step b) according to said first mode so that the total amount of organic and inorganic material introduced for the preparation of the material present in the catalyst according to the invention allows a micellization phenomenon leading to the mesostructuration of the matrix of each particle of said material. The material present in the catalyst according to the invention with hierarchical porosity in the fields of microporosity and mesoporosity and organized in the field of mesoporosity can advantageously be obtained in the form of powder, beads, pellets, granules, or extrudates, the shaping operations being carried out by conventional techniques known to those skilled in the art. Preferably, the material present in the catalyst according to the invention with a hierarchical porosity in the fields of microporosity and mesoporosity and organized in the mesoporosity range is obtained in the form of a powder, which consists of elementary spherical particles having a maximum diameter of 200 microns, which facilitates the diffusion of the reagents when the material is used as constituent element of the catalyst according to the invention in a process of hydroisomerization and hydrocracking of feeds from the Fischer-Tropsch process.

c) The mineral binder.

The catalyst according to the invention may advantageously contain an amorphous or poorly crystalline porous inorganic binder of the oxide type, the preferred binder being of the alumina type. The alumina compounds advantageously used according to the invention are partially soluble in acid medium. They are advantageously chosen wholly or partly from the group of alumina compounds of general formula AI ₂ O ₃ , nH ₂ O. It is particularly advantageous to use hydrated alumina compounds such as: hydrargillite, gibbsite, bayerite, boehmite, pseudo-boehmite and amorphous or essentially amorphous alumina gels. It is also advantageous to use the dehydrated forms of these compounds which consist of transition aluminas and which comprise at least one of the phases taken from the group: rho, khi, eta, gamma, kappa, theta, and delta, which differ essentially in the organization of their crystalline structure. The alpha alumina commonly called corundum can advantageously be incorporated in a small proportion in the support according to the invention. The aluminum hydroxide AI ₂ O ₃ , nH ₂ O used more preferably is advantageously boehmite, pseudo-boehmite and amorphous or essentially amorphous alumina gels. A mixture of these products under any combination may be used as well. Boehmite is generally described as an aluminum monohydrate of formula AI ₂ O ₃ , nH ₂ O which in fact encompasses a wide continuum of materials of variable degrees of hydration and organization with more or less well defined boundaries: the most hydrated gelatinous boehmite, with n being greater than 2, the pseudo-boehmite or the microcrystalline boehmite with n between 1 and 2, then the crystalline boehmite and finally the well crystallized boehmite in large crystals with n close to 1 The morphology of aluminum monohydrate can advantageously vary within wide limits between these two acicular and prismatic extreme forms. A whole set of variable shapes can advantageously be used between these two forms: chain, boats, interwoven plates.

Relatively pure aluminum hydrates can advantageously be used in powder form, amorphous or crystallized or crystallized containing an amorphous part. The aluminum hydrate can also advantageously be introduced in the form of aqueous suspensions or dispersions. The aqueous suspensions or dispersions of aluminum hydrate used according to the invention may advantageously be gelable or coagulable. The aqueous dispersions or suspensions may also advantageously be obtained as is well known to those skilled in the art by peptization in water or acidulated water of aluminum hydrates.

The aluminum hydrate dispersion may advantageously be produced by any method known to those skilled in the art: in a "batch" reactor, a continuous mixer, a kneader, a colloid mill. Such a mixture may advantageously also be carried out in a piston-flow reactor and in particular in a static mixer. Lightnin reactors can be mentioned.

In addition, it is also advantageous to use as a source of alumina an alumina having been previously subjected to a treatment that may improve its degree of dispersion. By way of example, it will be possible to improve the dispersion of the alumina source by a preliminary homogenization treatment. For homogenization, it is advantageous to use at least one of the homogenization treatments described in the text that follows.

The aqueous dispersions or suspensions of alumina that can be used include aqueous suspensions or dispersions of fine or ultra-fine boehmites which are composed of particles advantageously having dimensions in the colloidal field.

The fine or ultra-fine boehmites advantageously used according to the present invention may in particular have been obtained according to the French patent FR-B-1 261 182 and FR-B-1 381 282 or in the European patent application EP-A- 196. It is also advantageous to use aqueous suspensions or dispersions obtained from pseudo-boehmite, amorphous alumina gels, aluminum hydroxide gels or ultra-fine hydrargillite gels.

Aluminum monohydrate can advantageously be purchased from a variety of commercial sources of alumina such as in particular PURAL®, CATAPAL®, DISPERAL®, DISPAL® marketed by the company SASOL or HIQ® marketed by ALCOA, or according to the methods known to those skilled in the art: it can advantageously be prepared by partial dehydration of aluminum trihydrate by conventional methods or it can advantageously be prepared by precipitation. When these aluminas are in the form of a gel, they are advantageously peptized with water or an acidulated solution. In precipitation, the acid source may advantageously be for example chosen from at least one of the following compounds: aluminum chloride, aluminum sulphate, aluminum nitrate. The basic aluminum source may be selected from basic aluminum salts such as sodium aluminate and potassium aluminate.

d) Preparation of a support constituted by the amorphous material comprising structured hierarchical porosity silicon and the binder.

Formatting

The shaping of the support according to the invention can advantageously be prepared according to all the methods well known to those skilled in the art. The amorphous material may advantageously be introduced according to any method known to those skilled in the art and at any stage of the preparation of the support or catalyst.

According to a preferred method of preparation, the amorphous material may advantageously be introduced during the dissolution or suspension of the alumina compounds advantageously used according to the invention. The amorphous material may be, without limitation, for example in the form of powder, ground powder, suspension, suspension having undergone a deagglomeration treatment. Thus, for example, the amorphous material may advantageously be slurried acidulated or not at a concentration adjusted to the final content of amorphous material targeted on the support. This suspension, commonly known as a slurry, is then mixed with the alumina compounds. The support can advantageously be shaped by any technique known to those skilled in the art. The shaping can advantageously be carried out for example by extrusion, by pelletization, by the method of drop coagulation ("oil-drop"), by rotating plate granulation or by any other method well known to those skilled in the art. . The shaping can advantageously also be carried out in the presence of the various constituents of the catalyst and extrusion of the obtained mineral paste, by pelletizing, shaped into beads at the rotating bezel or drum, drop coagulation, "oil-drop" , "oil-up", or any other known method of agglomeration of a powder containing alumina and optionally other ingredients selected from those mentioned above. The catalysts used in the process according to the invention advantageously have the shape of spheres or extrudates. It is however advantageous that the catalyst is in the form of extrudates with a diameter of between 0.5 and 5 mm and more particularly between 0.7 and 2.5 mm. The shapes are advantageously cylindrical (which may be hollow or not), cylindrical twisted, multilobed (2, 3, 4 or 5 lobes for example), rings. The cylindrical shape is preferably used in a preferred manner, but any other form may advantageously be used.

Moreover, these supports implemented according to the present invention may advantageously have been treated as is well known to those skilled in the art by additives to facilitate the shaping and / or improve the final mechanical properties of the supports. By way of example of additives, mention may be made especially of cellulose, carboxymethylcellulose, carboxyethylcellulose, tall oil, xanthan gums, surfactants, flocculating agents such as polyacrylamides, carbon black, starches, stearic acid, polyacrylic alcohol, polyvinyl alcohol, biopolymers, glucose, polyethylene glycols, etc.

Water may be advantageously added or removed to adjust the viscosity of the paste to be extruded. This step can be performed at any stage of the kneading step. In order to adjust the solid content of the paste to be extruded to make it extrudable, it is also advantageous to add a predominantly solid compound and preferably an oxide or a hydrate. A hydrate is preferably used and even more preferably an aluminum hydrate. The loss on ignition of this hydrate is advantageously greater than 15%.

Extrusion can advantageously be performed by any conventional tool, commercially available. The paste resulting from the mixing is advantageously extruded through a die, for example by means of a piston or a single screw or twin extrusion screw. This extrusion step can advantageously be performed by any method known to those skilled in the art.

The support extrusions according to the invention advantageously have generally a crush strength of at least 70 N / cm and preferably greater than or equal to 100 N / cm.

Heat treatment

The drying is advantageously carried out by any technique known to those skilled in the art. To obtain the support of the present invention, it is preferable to calcine preferably in the presence of molecular oxygen, for example by conducting a sweep of air, at a temperature of less than or equal to 1100 ^° C. At least one calcination can advantageously be performed after any of the steps of the preparation. This treatment, for example, can be carried out in crossed bed, in a licked bed or in a static atmosphere. For example, the furnace used may advantageously be a rotating rotary kiln or be a vertical kiln with radial traversed layers. The calcination conditions (temperature and time) depend mainly on the maximum temperature of use of the catalyst. The preferred calcination conditions are advantageously between more than one hour at 200 ^° C. and less than one hour at 1100 ° C. The calcination can advantageously be carried out in the presence of water vapor. The final calcination may optionally be carried out in the presence of an acidic or basic vapor. For example, the calcination can advantageously be carried out under partial pressure of ammonia.

e) Deposit of the hydro-dehydrogenating function.

The hydro-dehydrogenating function may advantageously be introduced at any stage of the preparation, very preferably after forming the support. The shaping is advantageously followed by calcination. Under these conditions, the hydro-dehydrogenating function can also advantageously be introduced before or after this calcination. The preparation generally ends with a calcination at a temperature of 250 to 600 ^° C. Another of the preferred methods according to the present invention advantageously consists in shaping the support after kneading thereof, then passing the dough thus obtained to through a die to form extrudates with a diameter of between 0.4 and 4 mm. The hydro-dehydrogenating function may advantageously then be introduced in part only or in full, at the time of mixing. It can also advantageously be introduced by one or more ion exchange operations on the calcined support.

In a preferred manner, the support is impregnated with an aqueous solution. The impregnation of the support is preferably carried out by the "dry" impregnation method well known to those skilled in the art. The impregnation may advantageously be carried out in a single step by a solution containing all of the hydro-dehydrogenating elements constituting the final catalyst.

The hydro-dehydrogenating function can advantageously be introduced by one or more impregnation operations of the shaped and calcined support, with a solution containing at least one precursor of at least one oxide of at least one metal chosen from the group formed by the metals of group VIII and the metals of group VIB, the precursor (s) of at least one oxide of at least one metal of group VIII being preferably introduced after that (those) of the group VIB or at the same time as the last (s), if the catalyst contains at least one Group VIB metal and at least one Group VIII metal. In the case where the catalyst advantageously contains at least one element of group VIB, for example molybdenum, it is for example possible to impregnate the catalyst with a solution containing at least one element of group VIB, to dry, to calcine. The impregnation of molybdenum may advantageously be facilitated by the addition of phosphoric acid in the ammonium paramolybdate solutions, which also makes it possible to introduce the phosphorus so as to promote the catalytic activity.

The following elements: boron and / or silicon and / or phosphorus can be introduced into the catalyst at any level of the preparation and according to any technique known to those skilled in the art.

A preferred method according to the invention consists in depositing the selected promoter element or elements, for example the boron-silicon pair, on the calcined or non-calcined support, preferably calcined. For this purpose, an aqueous solution of at least one boron salt, such as ammonium biborate or ammonium pentaborate, is prepared in an alkaline medium and in the presence of hydrogen peroxide, and a so-called dry impregnation is carried out in which the pore volume of the support is filled with the solution containing, for example, boron. In the case where, for example, silicon is also deposited, for example a solution of a silicon-type silicon compound or a silicone oil emulsion is used.

The element (s) promoters) chosen (s) in the group formed by silicon, boron and phosphorus can advantageously be introduced by one or more impregnation operations with excess of solution on the calcined support. The boron source may advantageously be boric acid, preferably orthoboric acid H ₃ BO ₃ , ammonium biborate or pentaborate, boron oxide, boric esters. The boron may for example be introduced in the form of a mixture of boric acid, hydrogen peroxide and a basic organic compound containing nitrogen such as ammonia, primary and secondary amines, cyclic amines, compounds of the family of pyridine and quinolines and compounds of the pyrrole family. Boron may be introduced for example by a boric acid solution in a water / alcohol mixture.

The preferred phosphorus source is orthophosphoric acid H ₃ PO ₄ , but its salts and esters such as ammonium phosphates are also suitable. Phosphorus can for example be introduced in the form of a mixture of phosphoric acid and a compound Nitrogen-containing basic organic compounds such as ammonia, primary and secondary amines, cyclic amines, pyridine and quinoline family compounds, and pyrrole family compounds.

Many sources of silicon can advantageously be employed. Thus, it is possible to use tetraethylorthosilicate Si (OEt) ₄ , siloxanes, polysiloxanes, silicones, silicone emulsions, halide silicates such as ammonium fluorosilicate (NH ₄ ) ₂ SiF ₆ or sodium fluorosilicate Na ₂ SiF ₆ . Silicomolybdic acid and its salts, silicotungstic acid and its salts can also be advantageously employed. Silicon may advantageously be added for example by impregnation of ethyl silicate in solution in a water / alcohol mixture. The silicon may be added, for example, by impregnating a silicone or silicic acid silicon compound suspended in water.

The noble metals of group VIII of the catalyst of the present invention may advantageously be present in whole or in part in metal (s) and / or oxide form.

The sources of noble elements of group VIII which can advantageously be used are well known to those skilled in the art. For the noble metals halides are used, for example chlorides, nitrates, acids such as chloroplatinic acid, hydroxides, oxychlorides such as ruthenium ammoniacal oxychloride. It is also advantageous to use cationic complexes such as ammonium salts when it is desired to deposit the platinum on the amorphous material comprising silicon with a hierarchized porosity organized by cation exchange.

Embodiments according to the invention

a) First embodiment.

According to a preferred embodiment of the invention, the process comprises the following steps from a feed resulting from the Fischer-Tropsch synthesis: a) separation of a single so-called heavy fraction with an initial boiling point of between 120 - 200 ⁰ C, b) hydrotreatment of at least a portion of said heavy fraction, c) fractionation into at least 3 fractions:

at least one intermediate fraction having an initial boiling point T1 between 120 and 200 ^° C., and a final boiling point T 2 greater than 300 ° C. and less than 410 ° C., at least one light boiling fraction at least below the intermediate fraction, at least one heavy fraction boiling above the intermediate fraction, d) passing at least a portion of said intermediate fraction over a hydroisomerizing catalyst, e) passing at least a portion of said heavy fraction over the catalyst, hydrocracking / hydroisomerization according to the invention, f) distillation of the hydrocracked / hydroisomerized fractions to obtain middle distillates, and recycling of the residual fraction boiling above said middle distillates in step (e) on the catalyst according to the invention processing the heavy fraction.

The description of this embodiment will be made with reference to Figure 1 without Figure 1 limiting the interpretation.

Step (a)

The effluent from the Fischer-Tropsch synthesis unit arriving via line 1 is fractionated in a separation means (2) (for example by distillation) in at least two fractions: at least a light fraction and a heavy fraction at least initial boiling point equal to a temperature between 120 and 200 ⁰ C and preferably between 130 and 180 ⁰ C and even more preferably at a temperature of about 150 ⁰ C, in other words the cutting point is located between 120 and 200 ⁰ C. The light fraction of Figure 1 out through the pipe (3) and the heavy fraction through the pipe (4). This fractionation can be achieved by methods well known to those skilled in the art such as flash, distillation, etc. By way of non-limiting example, the effluent from the Fischer-Tropsch synthesis unit will be flashed, decanted to remove water and distilled to obtain at least the two fractions described above. . The light fraction is not treated according to the process of the invention but may for example constitute a good load for petrochemicals and more particularly for a steam cracking unit (5). The heavy fraction previously described is treated according to the process of the invention.

Step (b) At least a portion of said heavy fraction (step a) is allowed in the presence of hydrogen (line 6) in a zone (7) containing a hydrotreatment catalyst which aims to reduce the content of compounds olefinic and unsaturated as well as possibly decompose the oxygenates present in the fraction, as well as possibly break down any traces of sulfur and nitrogen compounds present in the heavy fraction. This hydrotreating step is non-converting, ie the conversion of the fraction 37O ⁰ C ⁺ fraction 37O ⁰ C ^" is preferably less than 20% by weight, preferably less than 10% by weight and very preferably less than 5% by weight.

The catalysts used in this step (b) are hydrotreating catalysts which are non-crunchy or slightly cracking and comprise at least one Group VIII metal and / or a Group VI metal of the periodic table of elements. The catalyst preferably comprises at least one metal of the metal group formed by nickel, molybdenum, tungsten, cobalt, ruthenium, indium, palladium and platinum and comprises at least one support. A combination of at least one Group VI metal (especially molybdenum or tungsten) and at least one Group VIII metal (especially cobalt and nickel) of the Periodic Table of Elements may be used. The concentration of the non-noble group VIII metal when it is used is 0.01 to 15% by weight of equivalent with respect to the finished catalyst and that of the group VI metal (in particular molybdenum or tungsten). is from 5% to 30% by weight of oxide equivalent relative to the finished catalyst. When a combination of Group VI and Group VIII metals is used, the catalyst is then preferably used in a sulfurous form.

Advantageously, at least one element selected from P, B, Si is deposited on the support. This catalyst may advantageously contain phosphorus; indeed, this compound provides two advantages to hydrotreatment catalysts: an ease of preparation, particularly in the impregnation of nickel and molybdenum solutions, and a better hydrogenation activity.

In a preferred catalyst, the total concentration of metals of groups VI and VIII, expressed as metal oxides, is between 5 and 40% by weight and preferably between 7 and 30% by weight and the weight ratio expressed as metal oxide. (or metals) of group VI on metal (or metals) of group VIII is between 1, 25 and 20 and preferably between 2 and 10. Advantageously, if there is phosphorus, the concentration of phosphorus oxide P ₂ O ₅ is less than 15% by weight and preferably less than 10% by weight. It is also possible to use a catalyst containing boron and phosphorus; advantageously boron and phosphorus are promoter elements deposited on the support, as is for example taught according to patent EP 297 949. The sum of the amounts of boron and phosphorus, respectively expressed by weight of boron trioxide and phosphorus pentoxide , relative to the carrier weight, is about 5 to 15% and the boron phosphorus atomic ratio is about 1: 1 to 2: 1 and at least 40% of the volume The total porosity of the finished catalyst is contained in pores with an average diameter greater than 13 nanometers. Preferably, the amount of Group VI metal such as molybdenum or tungsten is such that the Group VIB phosphorus atomic atomic ratio is about 0.5: 1 to 1.5: 1; the amounts of Group VIB metal and Group VIII metal, such as nickel or cobalt, are such that the atomic ratio of Group VIII metal to Group VIB metal is about 0.3: 1 to 0.7 1. The amounts of Group VIB metal expressed in weight of metal relative to the weight of finished catalyst is about 2 to 30% and the amount of Group VIII metal expressed as weight of metal relative to the weight of finished catalyst is about 0.01 to 15%. Another particularly advantageous catalyst contains promoter silicon deposited on the support. An interesting catalyst contains BSi or PSi.

Ni-sulfide catalysts on alumina, NiMo on alumina, NiMo on alumina doped with boron and phosphorus and NiMo on silica-alumina are also preferred. Advantageously, eta or gamma alumina will be chosen as support. In the case of the use of noble metals (platinum and / or palladium), the metal content is preferably between 0.05 and 3% by weight relative to the finished catalyst and preferably between 0.1 and 2% by weight. weight of the finished catalyst. The noble metal is preferably used in its reduced and non-sulphurized form. It is also possible to use a reduced, non-sulfurized nickel catalyst. In this case the metal content in its oxide form is between 0.5 and 25% by weight relative to the finished catalyst. Preferably, the catalyst also contains a group IB metal such as copper, in proportions such that the mass ratio of the group IB metal and nickel on the catalyst is between 1 and 1:30. These metals are deposited on a support which is preferably an alumina, but which may also be boron oxide, magnesia, zirconia, titanium oxide, a clay or a combination of these oxides. These catalysts can be prepared by any method known to those skilled in the art or can be acquired from companies specializing in the manufacture and sale of catalysts. In the hydrotreating reactor (7), the feedstock is brought into contact with the catalyst in the presence of hydrogen at operating temperatures and pressures which make it possible to hydrogenate the olefins present in the feedstock. Preferably, the catalyst and the operating conditions chosen will also make it possible to carry out the hydrodeoxygenation, ie the decomposition of the oxygenated compounds (mainly alcohols) and / or the hydrodesulfurization or hydrodenitrogenation of the possible traces of sulfur compounds. and / or nitrogen present in the charge. Reaction temperatures used in the hydrotreating reactor are between 100 and 400 ⁰ C ₁ , preferably between 150 and 350 ⁰ C, even more preferably between 150 and 300 ⁰ C. The total pressure range used varies from 5 to 150 bar, preferably from 10 to 100 bar and even more preferably from 10 to 90 bar. The hydrogen that feeds the hydrotreatment reactor is introduced at a rate such that the volume ratio hydrogen / hydrocarbons is between 50 and 3000 normal liters per liter, preferably between 100 and 2000 normal liters per liter and even more preferably between 150 and 1500 normal liters per liter. The charge rate is such that the hourly volume velocity is between 0.1 and 10 h ^-1 , preferably between 0.2 and 5 h ^-1 and even more preferably between 0.2 and 3 h ^-1 . Under these conditions, the content of unsaturated and oxygenated molecules is reduced to less than 0.5% by weight and to less than 0.1% by weight in general.The hydrotreating step is conducted under conditions such that the conversion to products having boiling points greater than or equal to 370 ^° C. in products having boiling points below 37 ^° C. is limited to 20% by weight, preferably less than 10% by weight, and so even more preferred is less than 5% by weight.

Step (c)

The effluent from the hydrotreatment reactor is fed via a pipe (8) into a fractionation zone (9) where it is fractionated into at least three fractions:

at least one light fraction (leaving via line 10), the constituent compounds of which have boiling points below a temperature T1 between 120 and 200 ^° C., and preferably between 130 and 180 ^° C. and even more preferred at a temperature of about 15O ⁰ C. In other words the cutting point is between 120 and 200 ⁰ C,

at least one intermediate fraction (line 11) comprising the compounds whose boiling points are between the cut point T1, previously defined, and a temperature T2 greater than 300 ^° C., more preferably still greater than 350 ° C and less than 41O ⁰ C or better at 370 ⁰ C - at least one so-called heavy fraction (line 12) comprising the compounds having boiling points higher than the cutting point T2 previously defined. Step (d)

At least a portion of said intermediate fraction is then introduced (line 11), as well as possibly a stream of hydrogen (line 13) into the zone (14) containing a hydroisomerization catalyst. The operating conditions under which this step (d) is carried out are as follows. The pressure is maintained between 2 and 150 bar and preferably between 5 and 100 bar and advantageously between 10 and 90 bar, the space velocity is between 0.1 h ^-1 and 10 h ^-1 and preferably between 0.2 and 7 h ^-1 and advantageously between 0.5 and 5.0 h ^-1 . The flow of hydrogen is adjusted to obtain a ratio of 100 to 2000 normal liters of hydrogen per liter of filler and preferably between 150 and 1500 normal liters. The temperature used in this step is between 200 and 450 ^° C. and preferably between 250 ^° C. and 450 ^° C., advantageously between 300 and 450 ^° C., and still more advantageously greater than 320 ° C. or for example between 320 and 420 ^° C.

The hydroisomerization step (d) is advantageously carried out under conditions such that the pass conversion into products with boiling points greater than or equal to 150 ^° C. into products having boiling points below 150 ^° C. the lowest possible, preferably less than 50%, even more preferably less than 30%, and very preferably less than 15% by weight, and allows to obtain middle distillates (gas oil and kerosene) having properties cold (pour point and freezing) sufficiently good to meet the specifications in force for this type of fuel.

Thus, in this step (d), it is sought to promote hydroisomerization rather than hydrocracking. The catalysts used are of the bifunctional type, that is to say that they have a hydro / dehydrogenating function and a hydroisomerizing function. The hydro / dehydrogenating function is generally provided either by noble metals (Pt and / or Pd) active in their reduced form or by Group VI non-noble metals (particularly molybdenum and tungsten) in combination with non-noble metals of Group VIII (particularly nickel and cobalt), preferably used in their sulfurized form. The hydroisomerizing function is provided by acidic solids, such as zeolites, halogenated alumina, pillar clays, heteropolyacids or sulphated zirconia. An alumina binder may also be used during the catalyst shaping step. The metal function can be introduced on the catalyst by any method known to those skilled in the art, such as for example comalaxing, dry impregnation, exchange impregnation. In the case where the hydroisomerization catalyst comprises at least one noble metal of group VIII, the noble metal content is advantageously between 0.01 and 5% by weight. weight with respect to the finished catalyst, preferably between 0.1 and 4% by weight and very preferably between 0.2 and 2% by weight. Before use in the reaction, the noble metal contained in the catalyst must be reduced. One of the preferred methods for conducting the reduction of the metal is the treatment under hydrogen at a temperature of between 150 ^° C. and 65 ^° C. and a total pressure of between 1 and 250 bar. For example, a reduction consists of a plateau at 150 ^° C. for two hours and then a rise in temperature to 450 ^° C. at a rate of 1 ° C./min and then a two-hour plateau at 450 ^° C. throughout this reduction step, the hydrogen flow rate is 1000 normal liters of hydrogen per liter of catalyst and the total pressure kept constant at 1 bar. Note also that any ex-situ reduction method is suitable.

In the case where the hydroisomerization catalyst comprises at least one group VI metal in combination with at least one group VIII non-noble metal, the group VI metal content of the hydroisomerization catalyst is advantageously comprised in oxide equivalent. between 5 and 40% by weight relative to the finished catalyst, preferably between 10 and 35% by weight and very preferably between 15 and 30% by weight and the group VIII metal content of said catalyst is advantageously included, in oxide equivalent, between 0.5 and 10% by weight relative to the finished catalyst, preferably between 1 and 8% by weight and very preferably between 1, 5 and 6% by weight. Before use in the reaction, group VI and non-noble Group VIII metals must be sulfurized. Any in-situ or ex-situ sulphurization method known to those skilled in the art is suitable.

The hydro / dehydrogenating metal function can advantageously be introduced on said catalyst by any method known to those skilled in the art, such as, for example, comalaxing, dry impregnation, exchange impregnation. According to step (d) of hydroisomerization of the process according to the invention, the hydroisomerisation catalyst comprises at least one molecular sieve, preferably at least one zeolite molecular sieve and more preferably at least one zeolite molecular sieve. 10 MR one-dimensional as a hydroisomerizing function. Zeolite molecular sieves are defined in the "Atlas of Zeolite Structure Types" classification, W. M. Meier, D. H. Oison and Ch. Baerlocher, 5th revised edition, 2001, Elsevier, to which the present application also refers. Zeolites are classified according to the size of their pore openings or channels.

One-dimensional 10 MR zeolite molecular sieves have pores or channels whose opening is defined by a ring of 10 oxygen atoms (10 MR aperture). The zeolite molecular sieve channels having a 10 MR aperture are advantageously unidirectional one-dimensional channels that open directly to the outside of said zeolite. 10 MR zeolite molecular sieves monodimensionnels present in said hydroisomerization catalyst advantageously comprise silicon and at least one element T selected from the group formed by aluminum, iron, gallium, phosphorus and boron, preferably aluminum. The Si / Al ratios of the zeolites described above are advantageously those obtained in the synthesis or obtained after post-synthesis dealumination treatments well known to those skilled in the art, such as and not limited to the hydrothermal treatments followed or no acid attacks or even direct acid attacks by solutions of mineral or organic acids. They are preferably almost completely in acid form, that is to say that the atomic ratio between the monovalent compensation cation (for example sodium) and the element T inserted in the crystalline lattice of the solid is advantageously less than 0.1, preferably less than 0.05 and most preferably less than 0.01. Thus, the zeolites used in the composition of said selective hydroisomerization catalyst are advantageously calcined and exchanged by at least one treatment with a solution of at least one ammonium salt so as to obtain the ammonium form of the zeolites which, once calcined, leads to to the acid form of said zeolites.

The said monodimensional 10 MR zeolite molecular sieve of said hydroisomerization catalyst is advantageously chosen from zeolite molecular sieves of structure type TON (chosen from ZSM-22 and NU-10, taken alone or as a mixture), FER (chosen from ZSM). -35 and ferrierite, taken alone or as a mixture), EUO (selected from EU-1 and ZSM-50, taken alone or as a mixture), SAPO-11 or zeolitic molecular sieves ZBM-30 or ZSM 48, taken alone or mixed. Preferably, said one-dimensional 10 MR zeolite molecular sieve is chosen from zeolitic molecular sieves ZBM-30, NU-10 and ZSM-22, taken alone or as a mixture. Very preferably, said one-dimensional 10 MR zeolite molecular sieve is ZBM-30 synthesized with the organic structuring agent triethylenetetramine. In fact, the use of said ZBM-30 produces much better results in terms of yield and activity than the other zeolites, and in particular that ZSM 48. The one-dimensional 10 MR zeolite molecular sieve content is advantageously between 5 and 95% by weight, preferably between 10 and 90% by weight, more preferably between 15 and 85% by weight and very preferably between 20 and 80% by weight relative to the finished catalyst. The catalysts obtained are shaped in the form of grains of different shapes and sizes. They are generally used in the form of cylindrical or multi-lobed extrusions such as bilobed, trilobed, straight-lobed or twisted, but may optionally be manufactured and used in the form of crushed powders, tablets, rings, beads. , wheels. The formatting can be made with other matrices than alumina, such as for example magnesia, amorphous silica-aluminas, natural clays (kaolin, bentonite, sepiolite, attapulgite), silica, titanium oxide, oxide boron, zirconia, aluminum phosphates, titanium phosphates, zirconium phosphates, coal and mixtures thereof. It is preferred to use matrices containing alumina, in all its forms known to those skilled in the art, and even more preferably aluminas, for example gamma-alumina. Other techniques than extrusion, such as pelletizing or coating, can be used.

Step

At least part of said heavy fraction is introduced via line (12) into a zone (15) where it is placed in the presence of hydrogen (25) in contact with a catalyst used in the process according to the present invention and under the operating conditions of the process of the present invention to produce a cut middle distillates (kerosene + diesel) having good properties cold.

The catalyst used in the zone (15) of step (e) to carry out the hydrocracking and hydroisomerization reactions of the heavy fraction is the catalyst defined in the first part of the patent application. It should be noted that the catalysts used in the reactors (14) and (15) may be strictly identical or different (for example, by varying the proportion and nature of the acidic solid in the catalyst, the nature of the binder or the quantity and nature of the hydrogenating phase). During this step (e) the fraction entering the reactor undergoes in contact with the catalyst and in the presence of hydrogen essentially hydrocracking reactions which, accompanied by hydroisomerization reactions of n-paraffins, will allow to improve the quality of the formed products and more particularly the cold properties of kerosene and diesel, and also to obtain very good yields of middle distillates. The conversion to products having boiling points greater than or equal to 37O ⁰ C in products with boiling points below 370 ⁰ C is greater than 50% by weight, often at least 60% and preferably greater than or equal to 70%.

Step (f)

The effluents leaving the reactors (14) and (15) are sent via lines (16) and (17) to a distillation train, which incorporates atmospheric distillation and optionally vacuum distillation, and which is intended to separate on the one hand the light products inevitably formed during steps (d) and (e) for example the gases (C ₁ -C ₄ ) (line 18) and a gasoline section (line 19), and distilling at least one section diesel (line 21) and a kerosene cut (line 20). The gas oil and kerosene fractions can be recycled (line 23) partly, jointly or separately, at the top of the hydroisomerization reactor (14) of step (d).

It is also distilled a fraction (line 22) boiling over diesel fuel, that is to say whose compounds which constitute it have boiling points higher than those of middle distillates (kerosene + diesel). This fraction, called the residual fraction, generally has an initial boiling point of at least 350 ^° C., preferably greater than 37 ^° C. This fraction is advantageously recycled via the pipe (22) at the top of the reactor (15). hydroisomerization and hydrocracking of the heavy fraction (step e). It may also be advantageous to recycle part of the kerosene and / or part of the gas oil in step (d), step (e) or both. Preferably, at least one of the kerosene and / or diesel fractions is partially recycled in step (d) (zone 14). It has been found that it is advantageous to recycle a portion of the kerosene to improve its cold properties. Advantageously and at the same time, the non-hydrocracked fraction is partially recycled in step (e) (zone 15).

It goes without saying that the diesel and kerosene cuts are preferably recovered separately, but the cutting points are adjusted by the operator according to his needs. In Figure 1, there is shown a distillation column (24), but two columns can be used to separately treat the sections from areas (14) and (15). In Figure 1, there is shown only the recycling of kerosene on the reactor catalyst (14). It goes without saying that one can also recycle a portion of the gas oil (separately or with kerosene) and preferably on the same catalyst as kerosene.

b) Second embodiment.

Another embodiment of the invention comprises the following steps: a) separation of at least a light fraction of the feedstock so as to obtain a single so-called heavy fraction with an initial boiling point of between 120-200 ^° C., b) optional hydrotreatment of said heavy fraction, optionally followed by a step c) removal of at least a portion of the water and optionally CO, CO ₂ , NH ₃ , H ₂ S ₁ d) passage over the catalyst hydrocracking / hydroisomerization according to the invention of at least a portion of said optionally hydrotreated fraction, conversion to the catalyst according to the invention above describes products with higher boiling points or at 37 ^° C. in products with a boiling point of less than 370 ^° C. is greater than

40% by weight, e) distillation of the hydrocracked / hydroisomerized fraction to obtain middle distillates, and recycling in step d) of the residual fraction boiling above said middle distillates.

The description of this embodiment will be made with reference to Figure 2 without Figure 2 limiting the interpretation.

Stage (a) The effluent from the Fischer-Tropsch synthesis unit arriving via line 1 is fractionated in a separation means (2) (for example by distillation) in at least two fractions: at least one light fraction and a heavy fraction with an initial boiling point of between 120 and 200 ° C. and preferably between 130 and 180 ° C. and even more preferably at a temperature of about 150 ^° C., in other words the cutting point is situated between 120 and 200 ^° C. The light fraction resulting from fractionation leaves via line (3) and the heavy fraction via line (4).

This fractionation can be achieved by methods well known to those skilled in the art such as flash, distillation, etc. By way of non-limiting example, the effluent from the Fischer-Tropsch synthesis unit will be flashed, decanted to remove water and distilled to obtain at least the two fractions described above. .

The light fraction is not treated according to the process of the invention but may for example constitute a good load for petrochemicals and more particularly for a steam cracking unit (5). The heavy fraction previously described is treated according to the process of the invention.

Step fb)

Optionally, this fraction is admitted in the presence of hydrogen (line 6) in a zone (7) containing a hydrotreatment catalyst which has the objective of reducing the content of olefinic and unsaturated compounds as well as possibly decomposing the oxygenated compounds ( mainly alcohols) present in the heavy fraction described above, as well as possibly breaking down any traces of sulfur and nitrogen compounds present in the heavy fraction. This hydrotreating step is non-converting, that is to say that the conversion of the fraction 37O ⁰ C ⁺ fraction 370 ⁰ C ^" is preferably less than 20% by weight, preferably less than 10% by weight and very preferably less than 5% by weight. The catalysts used in this step (b) are hydrotreatment catalysts described in step (b) of the first embodiment.

In the hydrotreating reactor (7), the feedstock is brought into contact with the catalyst in the presence of hydrogen at operating temperatures and pressures which make it possible to hydrogenate the olefins present in the feedstock. Preferably, the catalyst and the operating conditions chosen will also make it possible to carry out the hydrodeoxygenation, ie the decomposition of the oxygenated compounds (mainly alcohols) and / or the hydrodesulfurization or hydrodenitrogenation of the possible traces of sulfur compounds. and / or nitrogen present in the charge. The reaction temperatures used in the hydrotreating reactor are between 100 and 400 ^° C., preferably between 150 and 350 ^° C., more preferably between 150 and 300 ^° C. The total pressure range used varies from 5 to 150 bar, preferably between 10 and 100 bar and even more preferably between 10 and 90 bar. The hydrogen which feeds the hydrotreatment reactor is introduced at a rate such that the volume ratio hydrogen / hydrocarbons is between 50 to 3000 normal liters per liter, preferably between 100 and 2000 normal liters per liter and even more preferably between 150 and 1500 normal liters per liter. The charge rate is such that the hourly volume velocity is between 0.1 and 10 h ^-1 , preferably between 0.2 and 5 h ^-1 and even more preferably between 0.2 and 3 h ^-1 . Under these conditions, the content of unsaturated and oxygenated molecules is reduced to less than 0.5% by weight and to less than 0.1% by weight in general.The hydrotreating step is conducted under conditions such that the conversion to products having boiling points greater than or equal to 370 ^° C. in products having boiling points below 370 ^° C. is limited to 20% by weight, preferably less than 10% by weight, and so even more preferred is less than 5% by weight.

Step (c)

The effluent (line 8) from the hydrotreatment reactor (7) is optionally introduced into a water removal zone (9), the purpose of which is to eliminate at least partly the water produced during the reaction reactions. hydrotreating. This removal of water can be carried out with or without elimination of the gaseous fraction C ₄ ^" which is generally produced during the hydrotreatment step .The elimination of water is understood to mean the elimination of the water produced. by the hydrodeoxygenation reactions of the oxygenated compounds, but it may also include the elimination at least partly of the water of saturation of the hydrocarbons. the water can be made by all methods and techniques known to those skilled in the art, for example by drying, passage on a desiccant, flash, decantation.

Step (d) The heavy fraction (optionally hydrotreated) thus dried is then introduced (line 10) as well as optionally a stream of hydrogen (line 11) into the zone (12) containing the catalyst used in the process according to the invention and under the operating conditions of the process of the present invention. Another possibility of the process also according to the invention consists in sending all the effluent leaving the hydrotreating reactor (without drying) into the reactor containing the catalyst according to the invention and preferably at the same time as a stream of 'hydrogen. The catalyst used to carry out the hydrocracking and hydroisomerization reactions of the heavy fraction is the catalyst defined in the first part of the patent application. The operating conditions under which this step (d) is carried out are the operating conditions described according to the process according to the invention.

The hydroisomerization and hydrocracking step is carried out under conditions such that the pass conversion into products with boiling points greater than or equal to 370 ^° C. into products having boiling points below 370 ° C. is greater than 40% by weight, and even more preferably at least 50%, preferably greater than 60%, so as to obtain middle distillates (gas oil and kerosene) having sufficiently good cold properties (pour point , freezing point) to meet the applicable specifications for this type of fuel.

Step (e) The effluent (so-called hydrocracked and hydroisomerized fraction) leaving the reactor (12), step (d), is sent to a distillation train (13), which incorporates an atmospheric distillation and optionally a vacuum distillation, which is intended to separate the conversion products with a boiling point of less than 340 ^° C. and preferably less than 370 ° C., and especially including those formed during step (d) in the reactor (12), and of separating the residual fraction whose initial boiling point is generally greater than at least 34 ^° C. and preferably greater than or equal to at least 370 ^° C. Among the conversion products, it is separated in addition to the light gases C ₁ -C ₄ (line 14) at least one gasoline fraction (line 15), and at least one middle distillates fraction kerosene (line 16) and diesel (line 17). The residual fraction whose initial boiling point is generally greater than at least 340 ° C and preferably greater than or equal to at least 37O ⁰ C is recycled (line 18) at the head of the reactor (12) hydroisomerization and hydrocracking. It may also be advantageous to recycle (line 19) in step (d) (reactor 12) part of the kerosene and / or part of the gas oil thus obtained (s).

c) Third embodiment.

Another embodiment of the invention comprises the following steps: a) fractionation (step a) of the feedstock in at least three fractions:

at least one intermediate fraction having an initial boiling point T1 of between 120 and 200 ^° C., and a final boiling point T 2 greater than 300 ° C. and less than 410 ^° C.,

at least one light fraction boiling below the intermediate fraction,

at least one heavy fraction boiling above the intermediate fraction, b) hydrotreatment (step b) of at least a portion of said intermediate fraction, then passage (step d) in a treatment process of at least a part of the hydrotreated fraction on a hydroisomerizing catalyst, c) removal of at least a portion of the water produced during the hydrotreatment reactions and optionally CO, CO ₂ , NH ₃ , H ₂ S, d) passage (step d) on the hydrocracking / hydroisomerization catalyst according to the invention of at least a part of said heavy fraction with a conversion of products 370 ⁰ C ⁺ to products 370 ⁰ C ^" greater than 40% by weight, e) and f) distillation ( steps e and f) of at least a portion of the hydrocracked / hydroisomerized fractions to obtain middle distillates.

The description of this embodiment will be made with reference to FIG. 3 without limiting the interpretation.

Step (a)

The effluent from the Fischer-Tropsch synthesis unit comprises mainly paraffins, but also contains olefins and oxygenated compounds such as alcohols.

It also contains water, CO ₂ , CO and unreacted hydrogen as well as light hydrocarbon compounds Ci to C ₄ in the form of gas, or possibly sulfur or nitrogen impurities. The effluent from the Fischer-Tropsch synthesis unit arriving via line (1) is fractionated in a fractionation zone (2) in at least three fractions:

at least one light fraction (leaving via line 3), the constituent compounds of which have boiling points below a temperature T1 between 120 and 200 ° C., and preferably between 130 and 18O ⁰ C and even more preferably at a temperature of about 15O ⁰ C. In other words the cutting point is between 120 and 200 ⁰ C ₁

at least one intermediate fraction (line 4) comprising the compounds whose boiling points are between the cut point T1, previously defined, and a temperature T2 greater than 300 ^° C., more preferably still greater than 350 ° C and less than 410 ^° C. or better still at 370 ° C.

at least one so-called heavy fraction (line 5) comprising the compounds having boiling points higher than the previously defined cutting point T2. Cutting at 370 ^° C. makes it possible to separate at least 90% by weight of the oxygenated compounds and of the olefins, and most often at least 95% by weight. The heavy cut to be treated is then purified and removal of the heteroatoms or unsaturated by hydrotreating is then not necessary. Fractionation is obtained here by distillation, but it can be carried out in one or more steps and by other means than distillation.

This fractionation can be achieved by methods well known to those skilled in the art such as flash, distillation, etc. By way of non-limiting example, the effluent from the Fischer-Tropsch synthesis unit will be flashed, decanted to remove water and distilled to obtain at least the three fractions described above. . The light fraction is not treated according to the process of the invention but may for example constitute a good load for a petrochemical unit and more particularly for a steam cracker (steam cracking unit 6).

The heavier fractions previously described are treated according to the process of the invention.

Step (b)

Said intermediate fraction is admitted via line (4), in the presence of hydrogen supplied by the pipe (7), into a hydrotreatment zone (8) containing a hydrotreatment catalyst, which aims to reduce the olefinic and unsaturated compounds as well as possibly decompose the oxygenated compounds (mainly alcohols) present in the heavy fraction described above, as well as possibly decompose any traces of sulfur and nitrogen compounds present in the heavy fraction. This hydrotreating step is non-converting, that is to say that the conversion of the 15O ⁰ C ⁺ fraction to 150 ° C fraction is preferably less than 20% by weight, of preferred way less than 10% by weight and very preferably less than 5% by weight.

The catalysts used in this step (b) are hydrotreatment catalysts described in step (b) of the first embodiment. In the hydrotreatment reactor (8), the feedstock is brought into contact with the catalyst in the presence of hydrogen and at operating temperatures and pressures which make it possible to hydrogenate the olefins present in the feedstock. Preferably, the catalyst and the operating conditions chosen will also make it possible to carry out the hydrodeoxygenation, ie the decomposition of the oxygenated compounds (mainly alcohols) and / or the hydrodesulfurization or hydrodenitrogenation of the possible traces of sulfur compounds. and / or nitrogen present in the charge. The reaction temperatures used in the hydrotreating reactor are between 100 and 400 ^° C., preferably between 150 and 350 ^° C., more preferably between 150 and 300 ^° C. The total pressure range used varies from 5 to 150 bar, preferably 10 to 100 bar and even more preferably 10 to 90 bar. The hydrogen which feeds the hydrotreatment reactor is introduced at a rate such that the volume ratio hydrogen / hydrocarbons is between 50 to 3000 normal liters per liter, preferably between 100 and 2000 normal liters per liter and even more preferably between 150 and 1500 normal liters per liter. The charge rate is such that the hourly volume velocity is between 0.1 and 10 h ^-1 , preferably between 0.2 and 5 h ^-1 and even more preferably between 0.2 and 3 h ^-1 . Under these conditions, the content of unsaturated and oxygenated molecules is reduced to less than 0.5% by weight and to less than 0.1% by weight in general.The hydrotreating step is conducted under conditions such that the conversion to products having boiling points greater than or equal to 150 ° C in products having boiling points below 150 ° C is limited to 20% by weight, preferably less than 10% by weight and so even more preferred is less than 5% by weight.

Step (c) The effluent from the hydrotreatment reactor is optionally introduced into a water removal zone (9) which is intended to remove at least a portion of the water produced during the hydrotreatment reactions. . This removal of water can be carried out with or without elimination of the gaseous fraction C ₄ ^" which is generally produced during the hydrotreatment step .The elimination of water is understood to mean the elimination of the water produced. by the hydrodeoxygenation reactions of the oxygenated compounds, but it may also include the elimination at least partly of the saturation water of the hydrocarbons. The elimination of water can be carried out by any method and technique known to those skilled in the art, for example by drying, passing on a desiccant, flash, decantation.

Step (d)

The fraction thus possibly dried is then introduced (line 10), as well as possibly a stream of hydrogen (line 11) into the zone (12) containing a hydroisomerizing catalyst. Another possibility of the process also according to the invention consists in sending all of the effluent leaving the hydrotreating reactor (without drying) into the reactor containing the hydroisomerizing catalyst and preferably at the same time as a stream of hydrogen.

The hydroisomerizing catalysts are as described in step (d) of the first embodiment. The operating conditions under which this step (d) is carried out are as follows. The pressure is maintained between 2 and 150 bar and preferably between 5 and 100 bar and advantageously between 10 and 90 bar, the space velocity is between 0.1 h ^-1 and 10 h ^-1 and preferably between 0.2 and 7 hr ^-1 is preferably between 0.5 and 5.0 hr ^-1 . The hydrogen flow rate is adjusted to obtain a ratio of 100 to 2000 normal liters of hydrogen per liter of filler and preferably between 150 and 1500 normal liters of hydrogen per liter of filler. The temperature used in this step is between 200 and 450 ^° C. and preferably between 250 ^° C. and 450 ° C., advantageously between 300 and 450 ° C., and even more advantageously greater than 320 ° C. or for example between 320 and 420 ° C. vs. The hydroisomerization step (d) is advantageously carried out under conditions such that the pass conversion into products with boiling points greater than or equal to 150 ^° C. in products having boiling points below 150 ° C. is the lowest possible, preferably less than 50%, even more preferably less than 30%, and makes it possible to obtain middle distillates (gas oil and kerosene) having cold properties (pour point and freezing point) sufficiently good to meet the specifications in force for this type of fuel. Thus, in this step (d), it is sought to promote hydroisomerization rather than hydrocracking.

Step

Said heavy fraction whose boiling points are greater than the cutting point T2, previously defined, is introduced via the line (5) into a zone (13) where it is placed, presence of hydrogen (26), in contact with a catalyst according to the invention and under the operating conditions of the process of the present invention in order to produce a cut middle distillates (kerosene + gas oil) having good properties when cold. The catalyst used in the zone (13) of step (e) to carry out the hydrocracking and hydroisomerization reactions of the heavy fraction is the catalyst defined in the first part of the patent application. It should be noted that the catalysts used in the reactors (12) and (13) may be strictly identical or different (for example, by varying the proportion and the nature of the acidic solid in the catalyst, the nature of the binder or the quantity and nature of the hydrogenating phase). During this step (e) the fraction entering the reactor undergoes in contact with the catalyst and in the presence of hydrogen essentially hydrocracking reactions which, accompanied by hydroisomerization reactions of n-paraffins, will allow to improve the quality of the formed products and more particularly the cold properties of kerosene and diesel, and also to obtain very good yields of middle distillates. The conversion to products having boiling points greater than or equal to 370 ^° C. in products with boiling points below 370 ^° C. is greater than 40% by weight, often at least 50% and preferably greater than or equal to 60%.

In this step (e), it will therefore seek to promote hydrocracking, but preferably by limiting the cracking of middle distillates. The choice of operating conditions makes it possible to finely adjust the quality of the products (gas oil, kerosene) and in particular the cold properties of kerosene, while maintaining a good yield of diesel and / or kerosene. The method according to the invention makes it quite interesting to produce both kerosene and diesel fuel, which are of good quality while minimizing the production of lighter, unwanted cuts (naphtha, LPG).

Step (fl

The effluent at the outlet of the reactor (12), step (d), is sent to a distillation train, which incorporates an atmospheric distillation and optionally a vacuum distillation, and whose purpose is to separate, on the one hand, the light products inevitably formed during step (d), for example the gases (C ₁ -C ₄ ) (line 14) and a petrol section (line 15), and distilling at least one gasoil section (line 17) and a kerosene section ( driving 16). The gas oil and kerosene fractions can be recycled (line 25) partly, jointly or separately, at the top of the hydroisomerization reactor (12) of step (d). The effluent leaving step (e) is subjected to a separation step in a distillation train so as to separate on the one hand the light products inevitably formed during step (e), for example the gases (C ₁ -C ₄ ) (line 18) and a gasoline section (line 19), to distil a gasoil section (line 21) and a kerosene section (line 20) and to distil the fraction (line 22) boiling over diesel, that is to say whose compounds which constitute it have boiling points higher than those of middle distillates (kerosene + diesel). This fraction, termed the residual fraction, generally has an initial boiling point of at least 350 ⁰ C ₁ preferably greater than 370 ⁰ C. This non hydrocracked fraction is advantageously recycled to the head of the reactor (13) hydroisomerization and hydrocracking of step (e). It may also be advantageous to recycle a portion of the kerosene and / or a portion of the gas oil in step (d), step (f) or both. Preferably, at least one of the kerosene and / or diesel fractions is recycled in part (line 25) in step (d) (zone 12). It has been found that it is advantageous to recycle a portion of the kerosene to improve its cold properties. Advantageously and at the same time, the non-hydrocracked fraction is partially recycled in step (f) (zone 13).

It goes without saying that the diesel and kerosene cuts are preferably recovered separately, but the cutting points are adjusted by the operator according to his needs.

In Figure 3, there is shown two columns (23) and (24) of distillation, but only one can be used to treat all cuts from areas (12) and (13).

In Figure 3, there is shown only the recycling of kerosene on the reactor catalyst (12). It goes without saying that one can also recycle a portion of the gas oil (separately or with kerosene) and preferably on the same catalyst as kerosene. It is also possible to recycle part of the kerosene and / or a part of the gas oil produced in the lines (20) and (21).

d) Fourth embodiment.

Another embodiment of the invention comprises the following steps: a) optional fractionation of the feedstock into at least one heavy fraction with an initial boiling point of between 120 and 200 ^° C., and at least one light fraction boiling between below said heavy fraction, b) optional hydrotreatment of at least part of the feedstock or heavy fraction, optionally followed by c) the elimination of at least part of the water, d) passing at least a portion of the effluent or the optionally hydrotreated fraction onto a first hydrocracking / hydroisomerization catalyst according to the invention, e) distillation of the hydroisomerized and hydrocracked effluent to obtain middle distillates (kerosene , diesel) and a residual fraction boiling over the middle distillates, f) passing at least a portion of said residual heavy fraction and / or a portion of said middle distillates over a second hydrocracking / hydroisomerization catalyst according to and distillation of the resulting effluent to obtain middle distillates.

The description of this embodiment will be made with reference to FIGS. 4 and 5, without these figures limiting the interpretation.

Step (a)

When this step is implemented, the effluent from the Fischer-

Tropsch is fractionated (for example by distillation) in at least two fractions: at least one light fraction and at least one heavy fraction with initial boiling point equal to a temperature of between 120 and 200 ^° C. and preferably between 130 and 180 ^° C. ⁰ C and even more preferably at a temperature of about 150 ⁰ C, in other words the cutting point is between 120 and 200 ° C.

The heavy fraction generally has paraffin contents of at least 50% by weight. This fractionation can be achieved by methods well known to those skilled in the art such as flash, distillation, etc. By way of non-limiting example, the effluent from the Fischer-Tropsch synthesis unit will be flashed, decanted to remove water and distilled to obtain at least the two fractions described above. .

The light fraction is not treated according to the process of the invention but may for example constitute a good load for petrochemicals and more particularly for a steam cracking unit. At least one heavy fraction previously described is treated according to the method of the invention.

Step fb) Optionally, this fraction or at least part of the initial charge, is admitted via line (1) in the presence of hydrogen (brought by the pipe (2)) in a zone (3) containing a catalyst of hydrotreatment which aims to reduce the content of olefinic and unsaturated compounds as well as possibly to decompose the oxygenated compounds (mainly alcohols) present in the heavy fraction described above, as well as possibly to decompose possible traces of compounds sulfur and nitrogen present in the heavy fraction. This hydrotreating step is non-converting, i.e. the conversion of the fraction 370 ⁰ C. ⁺ fraction 370 ⁰ C ^"is preferably less than 20% by weight, preferably less than 10% by weight and very preferably less than 5% by weight The catalysts used in this step (b) are described in step (b) of the first embodiment.

In the hydrotreatment reactor (3), the feedstock is contacted with the catalyst in the presence of hydrogen and at operating temperatures and pressures for hydrogenation of the olefins present in the feedstock. Preferably, the catalyst and the operating conditions chosen will also make it possible to carry out the hydrodeoxygenation, ie the decomposition of the oxygenated compounds (mainly alcohols) and / or the hydrodesulfurization or hydrodenitrogenation of the possible traces of sulfur compounds. and / or nitrogen present in the charge. The reaction temperatures used in the hydrotreating reactor are between 100 and 400 ^° C., preferably between 150 and 35 ^° C., more preferably between 150 and 300 ° C. The total pressure range used varies from 5 to 150 bar, preferably from 10 to 100 bar and even more preferably from 10 to 90 bar. The hydrogen that feeds the hydrotreatment reactor is introduced at a rate such that the volume ratio hydrogen / hydrocarbons is between 50 and 3000 normal liters per liter, preferably between 100 and 2000 normal liters per liter and even more preferably between 150 and 1500 normal liters per liter. The charge rate is such that the hourly volume velocity is between 0.1 and 10 h ^-1 , preferably between 0.2 and 5 h ^-1 and even more preferably between 0.2 and 3 h ^-1 . Under these conditions, the content of unsaturated and oxygenated molecules is reduced to less than 0.5% by weight and to less than 0.1% by weight in general. The hydrotreating step is carried out under conditions such that the conversion to products having boiling points greater than or equal to 37O ⁰ C in products having boiling points below 370 ^° C. is limited to 20% by weight. weight, preferably less than 10% by weight and even more preferably less than 5% by weight.

Step (c)

The effluent (line 4) from the hydrotreatment reactor (3) is optionally introduced into a zone (5) for removing water, the purpose of which is to eliminate at least part of the water produced during the reaction reactions. hydrotreating. This elimination of water can be carried out with or without elimination of the gaseous fraction C ₄ ^' which is generally produced during the stage hydrotreating. The elimination of water is understood to mean the elimination of the water produced by the hydrodeoxygenation reactions of the oxygenated compounds, but it may also include the elimination at least partly of the saturation water of the hydrocarbons. The elimination of water can be carried out by any method and technique known to those skilled in the art, for example by drying, passing on a desiccant, flash, decantation.

Step (d)

At least part and preferably all of the hydrocarbon fraction (at least part of the feed or at least part of the heavy fraction of step a) or at least part of the hydrotreated fraction or feed and optionally dried) is then introduced (line 6) and optionally a stream of hydrogen (line 7) into the zone (8) containing the catalyst according to the invention. Another possibility of the process also according to the invention consists in sending part or all of the effluent leaving the hydrotreating reactor (without drying) into the reactor containing the catalyst according to the invention and preferably at the same time as a flow of hydrogen.

Before use in the reaction, if the hydrogenating phase of the catalyst consists of at least one noble metal, the metal contained in the catalyst must be reduced. One of the preferred methods for conducting the reduction of the metal is the treatment in hydrogen at a temperature of between 150 ^° C. and 650 ^° C. and a total pressure of between 1 and 250 bar. For example, a reduction consists of a stage at 150 ° C. for 2 hours then a rise in temperature up to 450 ^° C. at the rate of 1 ° C./min and then a plateau of 2 hours at 450 ^° C. throughout this reduction step, the hydrogen flow rate is 1000 normal liters of hydrogen per liter of catalyst. Note also that any ex-situ reduction method is suitable.

Step

The hydroisomerized and hydrocracked effluent leaving the reactor (8), step (d), is sent to a distillation train (9) which incorporates an atmospheric distillation and optionally a vacuum distillation which is intended to separate the conversion products. of boiling point below 34O ⁰ C and preferably below 370 ° C and including including those formed in step (d) in the reactor (8), and to separate the residual fraction whose initial point of boiling is generally greater than at least 34O ⁰ C and preferably greater than or equal to at least 370 ° C. Among the conversion products and hydroisomerized it is separated, in addition to the light gases C ₁ -C ₄ (line 10) at least one gasoline fraction (line 11), and at least a middle distillates fraction kerosene (line 12) and diesel (line 13).

Step (T) The process according to the invention uses a second zone (16) containing a hydrocracking and hydroisomerization catalyst described in the first part of the patent. It passes on this catalyst, in the presence of hydrogen (line 15) an effluent selected from a portion of the product kerosene (line 12), a portion of the gas oil (line 13) and the residual fraction and preferably the residual fraction of which the initial boiling point is generally greater than at least 37O ⁰ C.

During this step, the fraction entering the reactor (16) undergoes, in the presence of hydrogen, hydroisomerization and / or hydrocracking reactions in the reactor, which will make it possible to improve the quality of the products formed and more particularly the properties cold kerosene and diesel, and obtain improved middle distillate yields over the prior art.

The choice of operating conditions makes it possible to finely adjust the quality of the products (middle distillates) and in particular the cold properties.

The operating conditions in which this step (f) is carried out are the operating conditions in accordance with the process according to the invention. The operator will adjust the operating conditions on the first and second hydrocracking and hydroisomerization catalyst so as to obtain the desired product qualities and yields.

Thus, generally speaking, on the first catalyst, the conversion by pass to products with boiling points greater than or equal to 150 ^° C. in products with boiling points below 150 ^° C. is less than 50% by weight, of preferably less than 30% by weight. These conditions allow the individual to adjust the ratio kerosene / diesel produced and the cold properties of middle distillates, and more particularly kerosene. Also generally, on the second catalyst, when the residual fraction is treated, the pass conversion into products with a boiling point greater than or equal to 370 ° C. in products with a boiling point of less than 37 ^° C., is superior. 40% by weight, preferably greater than 50%, more preferably 60%. It can even be advantageous to have conversions of at least 80% weight.

When a part of the kerosene and / or a part of the gas oil is (are) treated on the second catalyst, the pass conversion into products with boiling points greater than or equal to 150 ° C in products with boiling points below 150 ⁰ C is less than 50% by weight, preferably less than 30%.

In general, the operating conditions applied in the reactors (8) and (16) may be different or identical. Preferably, the operating conditions used in the two hydroisomerization and hydrocracking reactors are chosen to be different in terms of operating pressure, temperature, hourly space velocity and H ₂ / feed ratio.

This embodiment allows the operator to adjust the qualities and / or yields of kerosene and diesel.

The effluent from the reactor (16) is then sent via line (17) in the distillation train so as to separate the conversion products, gasoline, kerosene and diesel.

In FIG. 4, there is shown an embodiment with the residual fraction (driving

14) passing in the zone (16) of hydroisomerization and hydrocracking (step f), the resulting effluent being sent (line 17) in the zone (9) of separation.

Advantageously, at the same time, the kerosene and / or the diesel fuel may be partially recycled (line 18) in the hydroisomerization and hydrocracking zone (8).

(step d) on the first catalyst.

In FIG. 5, a part of the kerosene and / or a part of the product gas oil passes into the hydroisomerization and hydrocracking zone (16) (step f), the effluent obtained being sent (conducting 17) in the separation zone (9). At the same time, the residual fraction (line 14) is recycled to the hydroisomerization and hydrocracking zone (8) (step d) on the first catalyst.

It has been found that it is advantageous to recycle a portion of the kerosene on a hydrocracking and hydroisomerization catalyst to improve its cold properties.

Figures 4 and 5 show only the recycling of kerosene. It goes without saying that one can also recycle a portion of the gas oil (separately or with kerosene) and preferably on the same catalyst as kerosene.

The invention is not limited to these four embodiments.

The products obtained The obtained gas oil (s) has a pour point of at most 0 ° C, generally below -1O ⁰ C and often below -15 ° C. The cetane number is greater than 60, generally greater than 65, often greater than 70.

The kerosene (s) obtained have a freezing point of not more than -35 ° C, generally less than -40 ^° C. The smoke point is greater than 25 mm, generally greater than 30 mm. In this process, gasoline production (not sought) is the most low possible. The gasoline yield will always be less than 50% by weight, preferably less than 40% by weight, advantageously less than 30% by weight or even 20% by weight or even 15% by weight.

The following examples illustrate the present invention without, however, limiting its scope.

Example 1 Preparation of the Hydrotreatment Catalyst (C1)

The catalyst is an industrial catalyst based on palladium on alumina noble metal with a palladium content of 0.3% by weight relative to the total weight of the finished catalyst, supplied by AXENS.

Example 2 Preparation of a Hydroisomerization and Hydrocracking Catalyst According to the Invention (C4)

a) Synthesis of an amorphous material comprising structured hierarchical porosity silicon

In the preparation described below, is calculated the ratio V _inor ganiqueA / _O rg _an ic from the mixture of step b). This ratio is defined as follows: Inorganic V / organic = (m _inor g ^* Porg) / (m _O rg

^* Pinorg) where m _in0r g is the final mass of the inorganic fraction in the form of condensed oxide (s), namely SiO ₂ and AlO ₂ , in the solid elementary particle obtained by atomization, m _org is the mass total of the non-volatile organic fraction found in the solid elemental particle obtained by atomization, namely the surfactant and the structuring agent, p _org and p _inorg are the densities respectively associated with the nonvolatile and inorganic organic fractions. In the following examples, we consider that p _org = 1 and p _inorg

= 2. Also the report Viπorganique / Vorganique ^β St Calculated COMM ^β being equal to V _in o ganic / Vorganique = (m + rn _If o2 ιo2 _A) / [2 * (m + nt structuring _age nitensioactif)] - L ' ethanol, soda, water does not count in the calculation of that report _nor ganiqueA vj / organic-

The preparation of the hierarchically porous material (C2) in the domains of microporosity and mesoporosity and organized in the mesoporosity domain whose microporous amorphous walls consist of ZSM-5 aluminosilicate protozeolites (MFI) such that the molar ratio Si / Al = 12 is carried out as follows.

6.86 g of a solution of tetrapropylammonium hydroxide (TPAOH 40% by mass in an aqueous solution) are added to 1.71 g of aluminum sec-butoxide (Al (O ^S C ₄ H ₉₎ ₃₎ . After 30 min with vigorous stirring at room temperature, 27 g of demineralized water and 17.66 g of tetraethylorthosilicate (TEOS) are added. Everything is left under lively agitation at room temperature for 4 days to obtain a clear solution. To this solution is then added a solution containing 66.61 g of ethanol, 61.24 g of water and 5.73 g of surfactant F127 (pH of the mixture = 12). Iπorganique the ratio V / Vo _r ga _n ic of the mixture is equal to 0.32 and is calculated as described above. The whole is left stirring for 10 minutes. The assembly is sent into the atomization chamber of the aerosol generator as described in the description above and the solution is sprayed in the form of fine droplets under the action of the carrier gas (dry air ) introduced under pressure (P = 1.5 bar). The droplets are dried according to the protocol described in the description of the invention above: they are conveyed via an O ₂ / N ₂ mixture in PVC tubes. They are then introduced into an oven set at a drying temperature set at 350 ^° C. The harvested powder is then dried for 18 hours in an oven at 95 ° C. The powder is then calcined under air for 5 hours at 550 ^° C. The solid is characterized by XRD at low angles, by nitrogen volumetric analysis, by TEM, by SEM, by FX. The TEM analysis shows that the final material has an organized mesoporosity characterized by a vermicular structure. The nitrogen volumetric analysis combined with the O ₃ method analysis leads to a microporous V _micro (N ₂ ) volume value of 0.03 ml / g, a mesoporous V _meso (N ₂₎ volume value. ) of 0.45 ml / g and a specific surface of the final material of S = 595 m ² / g. The mesoporous diameter φ characteristic of the mesostructured matrix is 5 nm. The small angle XRD analysis leads to the visualization of a correlation peak at the angle 2Θ = 0.98 °. The Bragg relation 2 d ^* sin (θ) = 1, 5406 makes it possible to calculate the correlation distance d between the organized mesopores of the material, namely d = 9 nm. The thickness of the walls of the mesostructured material defined by e = d - φ is therefore e = 4 nm. The Si / Al molar ratio obtained by FX is 12. An SEM image of the spherical elementary particles thus obtained indicates that these particles have a size characterized by a diameter ranging from 50 to 3000 nm, the size distribution of these particles being centered around 300 nm.

b) Preparation of the "C2 / Binder" Support According to the Invention (C3)

A "C2 / binder" support according to the invention (called C3) is manufactured in the following manner: 2 grams of solid C2 are mixed with 48 grams of a matrix composed of ultrafine tabular boehmite or alumina gel marketed under the name SB3 by Condéa Chemie Gmbh. This powder mixture was then mixed with an aqueous solution containing 66% by weight nitric acid (7% by weight of acid per gram of dry gel) and then kneaded for 15 minutes. The kneaded paste is then extruded through a die 1, 2 mm in diameter. The extrudates are then calcined at 500 ^° C. (rising ramp of 5 ° C / min) for 2 hours in a traversed bed in dry air (1 I air / h / gram of solid). This gives the solid C3.

c) Deposition of the hydro-dehydrogenating function (C4) The final catalyst (called C4) is obtained after deposition of the hydrogenating function on the support C3.

The extrudates of the support C3 are subjected to a step of dry impregnation with an aqueous solution of hexachloroplatinic acid H ₂ PtCl ₆ , left to mature in a water-based maturator for 24 hours at room temperature and then calcined at 500 ^° C. (ramp of rise of 5 ° C / min) for two hours in bed traversed in dry air (2 I air / h / gram of solid). The weight content of platinum of the finished catalyst after calcination is 0.89%. Its dispersion measured by H ₂ / O ₂ titration is 88% and the platinum distribution coefficient measured by a Castaing microprobe is equal to 0.85.

Example 3 Treatment of a Fischer-Tropsch Filler According to the Process According to the Invention

A feedstock from the Fischer-Tropsch synthesis on a cobalt catalyst is separated into two fractions, the heavier fraction having the characteristics given in Table 1. This heavy fraction is treated in a hydrogen-traversed bed lost on the catalyst. C1 hydrotreatment under operating conditions that allow the removal of olefinic and oxygen compounds and traces of nitrogen. The operating conditions selected are the following:

WH (load volume / volume of catalyst / hour) = 2 h ^-1 , - total working pressure: 50 bar, hydrogen / feed ratio: 200 normal liters / liter, temperature: 270 ° C.

Table 1: Characteristics of the heavy fraction.

After the hydrotreating, olefins content, oxygen compounds and nitrogen compounds from the effluent falls below a detection threshold, while the conversion of the fraction 370 ⁰ C. ⁺ fraction 370 ⁰ C ^"is negligible (less than 5% weight), see Table 2. The carbon monoxide and / or carbon dioxide and / or water and / or ammonia formed during the hydrotreatment are removed by a flash and decant step.

Table 2: Characteristics of the heavy fraction after processing.

The hydrotreated effluent constitutes the hydrocracking feedstock sent to the hydroisomerization and hydrocracking catalyst C4 according to the invention.

Before testing, the catalyst C4 undergoes a reduction step under the following operating conditions:

hydrogen flow rate: 1600 normal liters per hour and per liter of catalyst; rise in ambient temperature at 120 ^° C. at 10 ° C./min;

- one-hour stage at 120 ° C,

- rise from 120 ° C to 450 ° C at 5 ° C / min,

- two hour stage at 450 ° C,

- pressure: 1 bar After reduction, the catalytic test is carried out under the following conditions:

- total pressure of 40 bar,

- H ₂ ratio over load of 1200 normal liters / liter, - hourly volume velocity (WH) equal to 1 hr ^"1

The conversion of the fraction 370 ⁰ C ⁺ is taken equal to:

C (370 ° C ⁺ ) = [(% of 370 ^o C ^" _ef fiu _e πts) - (% of 370 ° σ _loaded )] / [100 - (% of 370 ⁰ C ^ e)] with

% of 370 ° C ^" efflue _n ts = mass content of compounds with boiling points below

370 ⁰ C in the effluents and

% 370 ^o C ^_'ch arge = weight content of compounds having lower boiling points

370 ⁰ C in the hydrocracking feedstock.

The reaction temperature is adjusted so as to obtain a conversion level of the fraction 370 ⁰ C ⁺ equal to 75% by weight. The gas chromatographic analyzes make it possible to obtain the distribution of the different cuts in the hydrocracked effluent (Table 3):

- C ₁ -C ₄ cut: hydrocarbons with 1 to 4 carbon atoms inclusive,

- C ₅ -C ₉ cut: hydrocarbons of 5 to 9 carbon atoms inclusive (naphtha cut),

- C ₁₀ -Cu cut: hydrocarbons of 10 to 14 carbon atoms inclusive (kerosene cut),

C ₁₅ -C ₂₂ fraction: hydrocarbons of 15 to 22 carbon atoms inclusive (gasoil fraction),

- C ₂₂ ⁺ cuts: hydrocarbons with more than 22 carbon atoms included (cut 370 ⁰ C ⁺ ).

Table 3: Arficial re artition of the hydrolytic effluent (GC)

These results show (Table 3) that the use of a hydroisomerization and hydrocracking catalyst according to the invention and in a process according to the invention allows by hydrocracking and hydroisomerization of a paraffinic filler resulting from the Fischer synthesis process. -Tropsch to produce middle distillates (kerosene and diesel).

Claims

claims

1. Process for producing middle distillates from a paraffinic feedstock produced by Fischer-Tropsch synthesis, using a hydrocracking / hydroisomerization catalyst comprising at least one hydro-dehydrogenating metal chosen from the group formed by the metals of the group VIB and Group VIII of the Periodic Table and a support formed of at least one amorphous material comprising structured hierarchical porosity silicon, consisting of at least two elementary spherical particles, each of said particles comprising an oxide-based matrix mesostructured silicon, having a mesopore diameter of between 1.5 and 30 nm and having amorphous and microporous walls with a thickness of between 1.5 and 50 nm, said elementary spherical particles having a maximum diameter of 200 microns.

2. The method of claim 1 wherein said method operates at a temperature between 270 and 400 ° C, at a pressure of between 1 and 9 MPa, at a space velocity between 0.5 and 5 h ^{* 1} and at a Hydrogen flow rate adjusted to obtain a ratio of 400 to 1500 normal liters of hydrogen per liter of charge.

3. Method according to one of claims 1 or 2 wherein said hydrocracking / hydroisomerization catalyst comprises:

0.1 to 60% of at least one hydro-dehydrogenating metal selected from the group consisting of Group VIB and Group VIII metals, from 40 to 99.9% of a support comprising:

0 to 99% of at least one amorphous or poorly crystallized porous inorganic binder of the oxide type,

- 0.01 to 60% of an amorphous material comprising silicon hierarchized and organized porosity, the percentages being expressed as a weight percentage relative to the total mass of the catalyst.

4. Method according to one of claims 1 to 3 wherein the elements of group VIII are selected from iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium or platinum , taken alone or mixed.

5. The method of claim 4 wherein the group VIII elements are the noble metals selected from platinum and palladium.

6. The method of claim 4 wherein the group VIII elements are non-noble metals selected from iron, cobalt and nickel.

7. The method of claim 4 wherein the group VIB elements are selected from tungsten and molybdenum.

8. Process according to one of Claims 3 to 7, in which the content of the hydro-dehydrogenating element chosen from the group formed by the metals of group VIB and of the non-noble group VIII is between 0.1 and 60% by weight relative to to the total mass of said catalyst.

9. Method according to one of claims 3 to 7 wherein the content of hydro-dehydrogenating element selected from the group formed by the noble metals of group VIII is between 0.05 and 10% by weight relative to the total mass of said catalyst.

10. Method according to one of claims 1 to 9 wherein said walls consist entirely of proto-zeolitic entities.

11. The method of claim 10 wherein the proto-zeolitic entities are species for the primer of at least one zeolite selected from aluminosilicates ZSM-5, ZSM-48, ZSM-22, ZSM-23, ZBM-30. , ElM ₁ EU-2, EU-11, Beta, zeolite A, Y, USY, VUSY, SDUSY, mordenite, NU-87, NU-88, NU-86, NU-85, IM-5, IM-12, IZM-2 and Ferrierite and / or at least one related solid selected from SAPO-11 and SAPO-34 silicoaluminophosphates.

12. Process according to claim 11, in which the proto-zeolitic entities are species for the primer of at least one zeolite chosen from aluminosilicates of structural type MFI, BEA, FAU, LTA and / or at least one related solid chosen from among silicoaluminophosphates of structural type AEL, CHA.

13. Method according to one of claims 1 to 11 wherein said method comprises the following steps: a) separation of a single so-called heavy fraction with initial boiling point between 120-200 ⁰ C ₁ b) hydrotreatment of at least a part of said heavy fraction, c) fractionation into at least 3 fractions: - at least an intermediate fraction having an initial boiling point T1 between

120 and 200 ^° C., and a final boiling point T 2 greater than 300 ^° C. and less than 410 ° C.,

at least one light fraction boiling below the intermediate fraction,

at least one heavy fraction boiling above the intermediate fraction, d) passing at least a portion of said intermediate fraction over a hydroisomerizing catalyst, e) passing at least a portion of said heavy fraction over the catalyst, hydrocracking / hydroisomerization according to the invention, f) distillation of the hydrocracked / hydroisomerized fractions to obtain middle distillates, and recycling of the residual fraction boiling above said middle distillates in step (e).

14. Method according to one of claims 1 to 11 wherein said method comprises the following steps: a) separation of at least a light fraction of the feed so as to obtain a single so-called heavy fraction with initial boiling point included between 120-200 ° C, b) optional hydrotreatment of said heavy fraction, optionally followed by a step c) removal of at least a portion of the water and optionally CO, CO ₂ , NH ₃ , H ₂ S d) passing through the hydrocracking / hydroisomerization catalyst according to the invention of at least a portion of said optionally hydrotreated fraction, conversion to the catalyst according to the invention described above for products with higher boiling points or equal to 370 ⁰ C in products with boiling points below 370 ⁰ C is greater than 40% by weight, e) distillation of the hydrocracked / hydroisomerized fraction to obtain middle distillates, and recycling in step d) of the fraction residue it boils above said middle distillates.

15. Method according to one of claims 1 to 11 wherein said method comprises the following steps: a) fractionation of the feedstock in at least three fractions: at least one intermediate fraction having an initial boiling point T1 between

120 and 200 ° C., and a final boiling point T 2 greater than 300 ^° C. and less than 410 ^° C., at least one light fraction boiling below the intermediate fraction,

at least one heavy fraction boiling above the intermediate fraction, b) hydrotreatment of at least a portion of said intermediate fraction, then passage into a process for treating at least a portion of the hydrotreated fraction on a

Hydroisomerizing catalyst, c) removal of at least a portion of the water produced during the hydrotreatment reactions and optionally CO, CO ₂ , NH ₃ , H ₂ S, d) passing over the hydrocracking / hydroisomerization catalyst according to the invention of at least part of said heavy fraction with a conversion of products greater than

Boiling points greater than or equal to 370 ^° C. in products with boiling points below 370 ^° C. above 40% by weight, e) and f) distillation of at least a portion of the hydrocracked / hydroisomerized fractions in order to obtain middle distillates.

16. The method according to one of claims 1 to 11 wherein said process comprises the following steps: a) optionally fractionation of the feedstock into at least one heavy fraction with an initial boiling point of between 120 and 200 ° C, and at least one light fraction boiling below said heavy fraction, b) optionally hydrotreating at least part of the feedstock or heavy fraction, optionally followed by c) removal of at least a portion of the feedstock or heavy fraction; water, d) passage of at least a portion of the effluent or the optionally hydrotreated fraction to a first hydrocracking / hydroisomerization catalyst according to

The invention, e) distillation of the hydroisomerized and hydrocracked effluent to obtain middle distillates and a residual fraction boiling over middle distillates, f) passage of at least a portion of said residual heavy fraction and / or a portion of said middle distillates on a second catalyst

30 _. hydrocracking / hydroisomerization according to the invention, and distillation of the resulting effluent to obtain middle distillates.

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