METHOD FOR PREPARING A CATALYST BASED ON CATALYST FINS

Abstract

A process for preparing a catalyst from catalyst fines comprising a metal of group VIB, a metal of group VIII, and an oxide support, said fines having a D90 size less than or equal to 500 micrometers, the process comprising the following steps: a) mixing said fines with an extrusion aid, and optionally an inorganic oxide binder, b) kneading the mixture obtained in step a) by adding an aqueous solution containing a carboxylic acid, c) optionally adding to said mixture obtained in step b) a neutralizing agent selected from an inorganic base and an organic base, d) shaping the mixture obtained in step b) or c) by extrusion to obtain a solid, e) drying the solid obtained in step d) at a temperature below 200°C, without subsequent calcination.

Description

Title of the invention: METHOD FOR PREPARING A CATALYST BASED ON CATALYST FINS Field of the invention

[0001] The present invention relates to a process for preparing a catalyst from catalyst fines comprising at least one metal from group VIB and / or at least one metal from group VIIIB, and an oxide support. These catalysts are particularly intended for use in hydrocarbon hydrotreating and / or hydrocracking units. Previous art

[0002] Usually, a hydrotreating catalyst for hydrocarbon cuts aims to eliminate the sulfur or nitrogen compounds contained in them in order to bring, for example, a petroleum product to the required specifications (sulfur content, aromatic content, etc.) for a given application (motor fuel, gasoline or diesel, domestic fuel oil, jet fuel).

[0003] Conventional hydrotreating and / or hydrocracking catalysts generally comprise an oxide support and an active phase based on metals from groups VIB and VIII in their oxide forms, as well as phosphorus. The preparation of these catalysts generally includes a step of impregnating the support with the metals and phosphorus, followed by drying and calcination to obtain the active phase in its oxide forms. Before their use in a hydrotreating and / or hydrocracking reaction, these catalysts are generally subjected to sulfidation to form the active species.

[0004] The addition of an organic compound to hydrotreating catalysts to improve their activity has been recommended by those skilled in the art, particularly for catalysts prepared by impregnation followed by drying without subsequent calcination. These catalysts are often called "additized dried catalysts." They are known to improve the dispersion of metals on the surface of the support and / or to play a beneficial role during the sulfidation of the catalysts. Numerous documents describe the use of various ranges of organic compounds as additives, such as nitrogen-containing organic compounds and / or oxygen-containing organic compounds. Several patents, for example, claim the use of carboxylic acids (EP1402948, EP0482817).In particular, in document EP0482817, citric acid, but also tartaric, butyric, hydroxyhexanoic, malic, gluconic, glyceric, glycolic, and hydroxybutyric acids were described.

[0005] During its operation in a hydrotreating and / or hydrocracking process, the catalyst becomes deactivated by the accumulation of coke and / or sulfur compounds or compounds containing other heteroelements on its surface. After a certain period, its replacement is therefore necessary. One way to dispose of spent catalysts is to send them to a landfill, but this is becoming increasingly difficult due to environmental constraints.

[0006] To combat these drawbacks, the regeneration of hydrotreating catalysts from middle distillates or spent residues is an economically and environmentally attractive process because it allows these catalysts to be reused in industrial units rather than being sent to landfill or recycled (metal recovery). However, regenerated catalysts are generally less active than the original catalysts.

[0007] To compensate for the lack of hydrodesulfurizing activity in the regenerated catalyst, an additional treatment known as "rejuvenation" can be applied. The rejuvenation process consists of re-impregnating the regenerated catalyst with a solution containing metallic precursors and / or organic or inorganic additives.

[0008] During the various stages of fresh catalyst preparation, regeneration, or rejuvenation processes, catalyst fines and / or out-of-specification catalysts (insufficient metal / metal content, insufficient mechanical strength, catalyst dimensions smaller than required) are generally produced. It would be advantageous to recycle these catalyst fines and / or out-of-specification catalysts to manufacture new catalysts.

[0009] The preparation of catalyst from catalyst fines is known.

[0010] US patents US6127299 and US6030915 describe a process for preparing a catalyst suitable for hydrotreating heavy hydrocarbon feedstocks, comprising regenerating a spent catalyst, grinding to obtain fines, mixing the fines with a binder, and shaping by extrusion in the presence of an inorganic acid, followed by drying and calcination. The fines incorporation rate is between 5 and 95 wt%.

[0011] US2012 / 0205290 relates to a hydrotreating catalyst comprising a support formed from a mixture of inorganic oxide powder and catalyst fines, said catalyst also containing a metallic component, a chelating agent, and a polar additive, which are subsequently impregnated. The incorporation rate of fines is a maximum of 50% by weight. The support is prepared by mixing in the presence of an inorganic acid, followed by drying and calcination.

[0012] Document CN112547080 describes a process for preparing a catalyst suitable for hydrotreating a diesel feedstock, comprising grinding to obtain fines, mixing the fines with a binder, and shaping by extrusion in the presence of a inorganic or organic acid, followed by drying and calcination at temperatures between 400 and 1000°C. The fines incorporation rate is between 10 and 50% by weight.

[0013] As indicated in the summarized documents above, it is desirable to have a process for preparing a catalyst that uses catalyst fines. However, it should be noted that the use of catalyst fines in the preparation and as components of certain catalyst compositions may result in a final catalyst exhibiting some reduced performance characteristics compared to new catalysts prepared without the use of fines.

[0014] The present invention aims to improve the processes for preparing a catalyst from catalyst fines to provide a final catalyst that can incorporate a high percentage of fines into the catalyst. Objects of the invention

[0015] The invention proposes a process for preparing a catalyst from catalyst fines comprising at least one metal from group VIB and / or at least one metal from group VIII, and an oxide support, said fines having a D90 size less than or equal to 500 micrometers, the process comprising at least the following steps:

[0016] a) said fines are mixed with an extrusion aid, and optionally an inorganic oxide binder,

[0017] b) the mixture obtained in step a) is kneaded by adding an aqueous solution containing a carboxylic acid,

[0018] c) optionally, a neutralizing agent chosen from an inorganic base and an organic base is added to the mixture obtained in step b),

[0019] d) the mixture obtained in step b) or c) is shaped by extrusion to obtain a solid,

[0020] e) the solid obtained in step d) is dried at a temperature below 200°C, without calcining it subsequently.

[0021] The preparation process according to the invention makes it possible to obtain a catalyst that is more active than comparable catalysts prepared with a final calcination step while ensuring good mechanical resistance.

[0022] Similarly, the preparation process according to the invention makes it possible to incorporate a high proportion of fines into the catalyst. Indeed, since the active phase containing the metals is supplied by the fines in the final catalyst, it is clearly advantageous to incorporate a high proportion of fines into the catalyst in order to obtain high activity and / or to avoid having to reintroduce metals by impregnation later. The preparation process according to the invention makes it possible, in particular, to obtain a catalyst with a proportion of fines greater than 50% by weight, the remainder being an inorganic oxide binder. It is even possible to obtain a catalyst with an incorporation rate of 100% by weight in fines, that is to say a catalyst which does not contain any added inorganic oxide binder.

[0023] According to one variant, the D90 size of the fines is less than 300 micrometers.

[0024] According to one variant, the fines content is between 10% and 100% relative to the weight of the catalyst prepared by the process according to the invention.

[0025] According to one variant, the fines have a group VIB metal content of between 5 and 40% by weight of oxide of group VIB metal and a group VIII metal content of between 1 and 50% by weight of oxide of group VIII metal relative to the weight of the fines.

[0026] According to one variant, the fine oxide support is chosen from alumina, silica, silica-alumina, titanium or magnesium oxide used alone or in mixture with alumina or silica-alumina.

[0027] According to one variant, said inorganic oxide binder is present and is selected from the group formed by the following oxides or their hydrated forms: alumina, silica, silica-alumina, clays, titanium oxide, boron oxide and zirconia, taken alone or in mixture.

[0028] According to one variant, the content of extrusion aid agent is between 0.1 and 10% weight relative to the weight of dry fines and optional dry inorganic oxide binder introduced in step a).

[0029] According to one variant, the extrusion aid agent is chosen from methylcellulose, cellulose, carboxy-methyl-cellulose, carboxy-ethyl-cellulose.

[0030] According to one variant, the carboxylic acid is chosen from formic acid, acetic acid, oxalic acid, citric acid, γ-ketovaleric acid, alone or in mixture.

[0031] According to one variant, the amount of carboxylic acid added is defined by a total acid rate, expressed as a percentage relative to the weight of the dry fines and the optional dry inorganic oxide binder introduced in step a) and is between 0.1 and 20 wt%.

[0032] According to one variant, the aqueous solution containing a carboxylic acid further contains at least one organic compound exhibiting complexing properties.

[0033] According to one variant, when step c) is carried out, said mixture obtained in step b) is added a neutralizing agent chosen from an inorganic base and an organic base, said inorganic base being chosen from sodium hydroxide, potassium hydroxide, and ammonia, alone or in mixture and said organic base being chosen from amines and quaternary ammonium compounds, alone or in mixture.

[0034] According to one variant, the quantity of neutralizing agent is defined by a neutralization rate expressed as a base molar percentage relative to the number of moles of protons present in step b) and is between 1 and 100%.

[0035] According to one variant, the process includes a step f) in which at least one metal from group VIB and / or at least one metal from group VIII, and optionally phosphorus and / or at least one organic compound comprising oxygen and / or nitrogen and / or sulfur, is brought into contact with said catalyst obtained after step e) of drying, the contacting being followed by a drying step at a temperature below 200°C, without subsequent calcination.

[0036] According to one embodiment, said catalyst obtained after drying step e) or after step f) is subjected to a sulfidation step, without an intermediate calcination step. Definitions

[0037] In the sense of the present invention, the different embodiments presented can be used alone or in combination with each other, without limitation of combination.

[0038] In the sense of the present invention, the different parameter ranges for a given step, such as pressure ranges and temperature ranges, can be used alone or in combination. For example, in the sense of the present invention, a preferred range of pressure values ​​can be combined with a preferred range of temperature values.

[0039] In the following text, the expressions "between ... and ..." and "between ... and ..." are equivalent and mean that the limit values ​​of the interval are included in the range of values ​​described. If this were not the case and the limit values ​​were not included in the range described, such clarification will be provided by the present invention.

[0040] In this description, the term "include" is synonymous with (means the same as) "include" and "contain," and is inclusive or open and does not exclude other elements not mentioned. It is understood that the term "include" includes the exclusive and closed term "consist."

[0041] According to the present invention, the pressures are absolute pressures, also noted as abs., and are given in absolute MPa (or abs. MPa), unless otherwise indicated.

[0042] In the following text, the groups of chemical elements are given according to the CAS classification (CRC Handbook of Chemistry and Physics, publisher CRC Press, editor-in-chief DR Lide, 81st edition, 2000-2001). For example, group VIII (or VIIIB) according to the CAS classification corresponds to the metals of columns 8, 9 and 10 according to the new IUP AC classification, and group VIB to the metals of column 6.

[0043] Elemental analyses, typically by inductively coupled plasma (ICP) spectrometry, or by X-ray fluorescence spectrometry, more commonly called X-ray fluorescence (FX), make it possible to quantify the content of the different elements of the fines pretreated at 550°C under air.

[0044] The catalyst obtained by the process according to the invention has a specific pore distribution, where the macroporous and mesoporous volumes are measured by mercury intrusion and the microporous volume is measured by nitrogen adsorption.

[0045] By "macropores" we mean pores whose opening is greater than 50 nm.

[0046] By "mesopores", we mean pores whose opening is between 2 nm and 50 nm, inclusive.

[0047] By "micropores" we mean pores whose opening is less than 2 nm.

[0048] In the following description of the invention, the term specific surface means the surface specific BET determined by nitrogen adsorption in accordance with ASTM D 3663-78 established from the BRUNAUER-EMMETT-TELLER method described in the periodical "The Journal of American Society", 60, 309, (1938).

[0049] The volume of macropores and mesopores is measured by mercury intrusion porosimetry according to ASTM D4284-83 at a maximum pressure of 4000 bar (400 MPa), using a surface tension of 484 dyne / cm and a contact angle of 140°. The wetting angle was taken to be 140° following the recommendations of the book "Techniques de l'ingénieur, traité analyse et caractérisation", P 1050-5, written by Jean Charpin and Bernard Rasneur.

[0050] The value from which mercury fills all intergranular voids is set at 0.2 MPa, and beyond this is considered that mercury penetrates the pores of the sample.

[0051] The macroporous volume of the catalyst is defined as the cumulative volume of mercury introduced at a pressure between 0.2 MPa and 30 MPa, corresponding to the volume contained in pores with an apparent diameter greater than 50 nm.

[0052] The mesoporous volume of the catalyst is defined as the cumulative volume of mercury introduced at a pressure between 30 MPa and 400 MPa, corresponding to the volume contained in the pores with an apparent diameter between 3.6 nm and 50 nm.

[0053] The volume of the micropores is measured by nitrogen porosimetry. The quantitative analysis of the microporosity is carried out using the "t" method (Lippens-De Boer method, 1965) which corresponds to a transform of the initial adsorption isotherm as described in the book "Adsorption by powders and porous solids. Principles, methodology and applications" written by F. Rouquérol, J. Rouquérol and K. Sing, Academie Press, 1999.

[0054] In the following description of the invention, the total porous volume of the catalyst is understood to mean the sum of the mesoporous, macroporous (measured by intrusion in a mercury porosimeter) and microporous (measured by nitrogen porosimetry) volumes.

[0055] The mechanical strength of the material according to the invention is determined by the grain-by-grain (GBG) crush test. This is a standardized test (ASTM D4179-01) which consists of subjecting a material in the form of a millimeter-sized object, such as a ball, pellet, or extrudate, to a compressive force generating fracture. The analysis is repeated on a number of individual solids, typically between 10 and 200. The average of the measured lateral fracture forces constitutes the average EGG, which is expressed in the case of granules in units of force (N), and in the case of extrudates in units of force per unit length (daN / mm or decaNewton per millimeter of extrudate length).

[0056] The contents of the different components used in the process according to the invention (fines, binder, carboxylic acid, neutralizing agent...) are expressed on the basis of the weight of the dry fines and possibly on the basis of the weight of the dry inorganic oxide binder when present.

[0057] The loss on ignition (or LOI) of a solid is the relative mass loss (expressed as a percentage) of a solid when it has been heated to 1000°C for 3 hours in a muffle furnace. LOI thus expresses the water and organic compound content. When the fines contain molybdenum, the LOI is measured at 550°C for 3 hours in a muffle furnace. This measurement allows the weight of the dry fines and dry binder to be determined. Detailed description of the invention

[0058] The present invention proposes a method for preparing a catalyst from catalyst fines. The thin ones

[0059] Catalyst fines can originate from a fresh, used, regenerated and / or rejuvenated catalyst. They can also originate from a fresh, used, regenerated and / or rejuvenated capture mass.

[0060] Preferably, the fines come from a fresh catalyst or a regenerated catalyst. Preferably, the fines come from a regenerated catalyst.

[0061] According to a first embodiment, the fines can come from a fresh catalyst. This term includes a catalyst that has not already been used in production, but which is generally out of specification, for example because it contains an insufficient metal content or too low mechanical resistance, or is smaller than the required size resulting from the various unit operations of manufacturing new catalysts.

[0062] According to a second embodiment, the fines may originate from a spent catalyst. A "spent" catalyst is understood to mean a catalyst that is at least partially spent, that is, one that has already been used in production, particularly in hydrotreating or hydroconversion plants such as hydrocracking. A "spent" catalyst is understood to include, in particular, a catalyst that is at least partially spent but has not been regenerated or rejuvenated. The spent catalyst may comprise coke and / or sulfur. as described above. The spent catalyst may undergo a deoiling step before grinding.

[0063] The oil removal step generally comprises contacting the spent catalyst with a stream of inert gas (i.e., essentially oxygen-free), for example in a nitrogen or similar atmosphere, at a temperature between 300°C and 400°C, preferably between 300°C and 350°C. The inert gas flow rate, expressed as a flow rate per unit volume of catalyst, is 5 to 150 NL.h⁻¹ for 3 to 7 hours. Alternatively, the oil removal step can be carried out using light hydrocarbons, by steam treatment, or any other similar process.

[0064] According to a third embodiment, the fines can come from a regenerated catalyst. This term includes a used catalyst, possibly de-oiled, which has been subjected to a coke and sulfur removal step: a regeneration step, which makes it possible to remove all or part of the coke, sulfur and / or chlorine possibly deposited on the catalyst.

[0065] The regeneration step is generally carried out in a gas stream containing oxygen, usually air. The water content in the gas is generally between 0 and 50 wt%. The gas flow rate, in terms of flow rate per unit volume of the at least partially spent catalyst, is preferably 20 to 2000 NL.h⁻¹, more preferably 30 to 1000 NL.h⁻¹, and particularly preferably 40 to 500 NL.h⁻¹. The regeneration time is preferably 2 hours or more, more preferably 2.5 hours or more, and particularly preferably 3 hours or more. The regeneration of the spent catalyst, possibly de-oiled, is generally carried out at a temperature between 320°C and 550°C, preferably between 360°C and 500°C.

[0066] According to a fourth embodiment, the fines can originate from a rejuvenated catalyst. This term includes a regenerated catalyst that has been re-impregnated with a solution containing metallic precursors and / or organic or inorganic additives.

[0067] Fines can be naturally produced during the various stages of catalyst manufacturing or during the loading or unloading operations of a catalyst from the industrial unit from which it is removed.

[0068] Fines can also be produced during regeneration. Indeed, the quantity of fines produced during regeneration is generally quite high given the damage caused to the catalyst structure by the high temperature of regeneration.

[0069] Fines can also be deliberately produced, for example by grinding a fresh catalyst that is out of size (or not) or a used catalyst that has been regenerated and / or rejuvenated.

[0070] An important feature of the invention is that the catalyst fines are in the form of reasonably small particles or in a powdery form so as to allow the catalyst fines to be mixed with other components to provide a mixture that can be shaped or agglomerated.

[0071] Thus, fines with a D90 size that is too large, or the catalyst used to produce fines, are subjected to a preliminary grinding step if necessary. It is of course possible to carry out several successive grinding steps to achieve the desired particle size D90. Any method known to those skilled in the art can be implemented to perform this crushing or grinding step, such as, for example, the use of a ball mill or a blade mill.In this case, the grinding step is carried out in such a way as to obtain fines having a D90 size less than or equal to 500 micrometers, preferably less than 300 micrometers, or even less than 200 micrometers, preferably between 1 and 500 micrometers, preferably between 1 and 300 micrometers, preferably between 1 and 200 micrometers, or even between 1 and 160 micrometers or between 1 and 100 micrometers, even more preferably between 1 and 60 micrometers, and particularly preferably between 1 and 20 micrometers.

[0072] The D90 size is defined in that 90% of the volume population of the fines has an equivalent diameter less than or equal to 500 micrometers, preferably less than 300 micrometers, or even less than 200 micrometers, and generally between 1 and 500 micrometers, preferably between 1 and 300, preferably between 1 and 200 micrometers, or even between 1 and 160 micrometers or between 1 and 100 micrometers, even more preferably between 1 and 60 micrometers, and particularly preferably between 1 and 20 micrometers. The equivalent diameter, denoted "de", is defined according to the following relationship: de = 6V / S, where V is the volume of the particle and S is the surface area of ​​the sphere with the same volume as the particle.

[0073] The particle size distribution of fines is measured by laser scattering particle size analysis according to ASTM D4464. This technique is based on the principle of light diffraction. Suspended particles (in a solvent such as water or in an air stream) diffract the light emitted by a laser beam contained in the instrument. The spatial distribution of this light, a function of particle size, is recorded by an array of photodiodes. Analysis of this distribution in the focal plane makes it possible to determine the proportion of each size class and leads to knowledge of the particle size distribution of the grains contained in the sample.

[0074] The fines have the same composition as the catalysts from which they originate. The fines, whether they come from a fresh, used, regenerated and / or rejuvenated catalyst, comprise at least one oxide support, at least one metal from Group VIII and / or less one metal from group VIB, and optionally phosphorus and optionally an organic compound comprising oxygen and / or nitrogen and / or sulfur. They may also, but are not limited to, include coke and / or sulfur, particularly when they are fines from a regenerated or spent catalyst.

[0075] The oxide support is usually a porous solid selected from the group consisting of: aluminas, silica, silica-aluminas, or titanium or magnesium oxides used alone or in a mixture with alumina or silica-alumina. Preferably, the oxide support is essentially composed of at least one transition alumina, that is to say, it comprises at least 51 wt%, preferably at least 60 wt%, most preferably at least 80 wt%, or even at least 90 wt% of transition alumina. It is preferably composed solely of one transition alumina. Preferably, the oxide support of said catalyst is a gamma-phase alumina.

[0076] In another preferred case, the oxide present in the oxide support is a silica-alumina containing at least 50% by weight of alumina relative to the total weight of the composite support. The silica content in the support is at most 50% by weight relative to the total weight of the support, most often less than or equal to 45% by weight, preferably less than or equal to 40% by weight.

[0077] According to a particularly preferred embodiment, the oxide support consists of alumina, silica or silica-alumina.

[0078] The oxide support may also advantageously contain from 0.1 to 80 wt%, preferably from 0.1 to 50 wt%, of zeolite relative to the total weight of the support. In this case, all known sources of zeolite and all associated preparation methods may be incorporated. Preferably, the zeolite is selected from the FAU, BEA, ISV, IWR, IWW, MEI, and UWY groups, and more preferably, the zeolite is selected from the FAU and BEA groups, such as Y and / or beta zeolite, and particularly preferably, such as USY and / or beta zeolite.

[0079] The oxide support advantageously has a total pore volume of between 0.1 and 1.5 mL / g, preferably between 0.4 and 1.1 mL / g. The total pore volume is measured by mercury porosimetry according to ASTM D4284-92 with a wetting angle of 140°, for example using a Microméritics™ Autopore III™ instrument.

[0080] The specific surface area of ​​the oxide support is advantageously between 5 and 400 m².g*, preferably between 10 and 350 m².g*, more preferably between 40 and 350 m².g*. The specific surface area is determined in the present invention by the BET method according to ASTM D3663.

[0081] The active phase of the fines comprises at least one metal from Group VIB and / or at least one metal from Group VIII. The metal from Group VIB is preferably chosen from molybdenum and tungsten, or a mixture of these two elements. The metal from Group VIII is preferably chosen from cobalt, nickel, and a mixture of these two elements. The active phase is preferably chosen from the group formed by the combination of the elements nickel-molybdenum, cobalt-molybdenum, nickel-cobalt-molybdenum, nickel-tungsten, nickel-molybdenum-tungsten, and nickel-cobalt-tungsten.

[0082] The Group VIII metal content is between 1 and 50% by weight of Group VIII metal oxide relative to the weight of the fines, preferably between 1.5 and 9% by weight, and preferably between 2 and 8% by weight. When the metal is cobalt or nickel, the metal content is expressed as CoO and NiO, respectively.

[0083] The metal content of group VIB is between 5 and 40 wt% of the oxide of the group VIB metal relative to the total weight of the fines, preferably between 8 and 35 wt%, most preferably between 10 and 30 wt%. When the metal is molybdenum or tungsten, the metal content is expressed as MoO3 and WO3 respectively.

[0084] The molar ratio of group VIII metal to group VIB metal in the fines, when these contain both types of metals, is preferably between 0.1 and 0.8, preferably between 0.15 and 0.6 and even more preferably between 0.2 and 0.6 or between 0.3 and 0.5.

[0085] The fines may also include phosphorus as a dopant. The dopant is an added element which, in itself, has no catalytic character but which increases the catalytic activity of the active phase.

[0086] The phosphorus content is then preferably between 0.1 and 20% by weight expressed as P2O5 relative to the total weight of the fines, preferably between 0.2 and 15% by weight expressed as P2O5, and most preferably between 0.3 and 8% by weight expressed as P2O5.

[0087] The molar ratio of phosphorus to the element of group VIB is greater than or equal to 0.05, preferably greater than or equal to 0.07, preferably between 0.08 and 1, preferably between 0.01 and 0.9 and most preferably between 0.15 and 0.6.

[0088] The fines may contain sulfur. The sulfur content is then less than 15% by weight, preferably between 1 and 15% by weight expressed as an element relative to the total weight of the fines, preferably between 2 and 12%, and most preferably between 4 and 10% by weight. The sulfur content is measured by elemental analysis according to ASTM D5373.

[0089] The fines may include coke, particularly when they originate from a spent catalyst that has not been regenerated. It should be noted that the term "coke" in this application refers to a hydrocarbon-based substance deposited on the surface of the catalyst during its use, highly cyclized and condensed, and having an appearance similar to graphite.

[0090] The coke content, expressed as a percentage by weight of the carbon element, is less than 20% by weight and may be between 2 and 20% by weight, preferably between 3 and 16% by weight, and in particular between 4 and 14% by weight relative to the total weight of the fines. The coke content is determined according to ASTM D5373.

[0091] Preferably, the fines contain little or no sulfur. The sulfur content is then preferably less than 5% by weight, preferably between 0.1% and 3% by weight, preferably between 0.1% and 2% by weight, and particularly preferably between 0.1% and 0.8% by weight relative to the total weight of the fines. The fines may also be sulfur-free.

[0092] Preferably, the fines contain little or no coke. The coke content is then preferably less than 5% by weight, preferably between 0.1% and 4% by weight, preferably between 0.1% and 2% by weight, and particularly preferably between 0.1% and 1% by weight, or even between 0.1% and 0.5% by weight relative to the total weight of the fines. The fines may also contain no coke.

[0093] Optionally, the fines may also have a low content of contaminants from the feed treated by the spent or regenerated catalyst from which it originates such as nickel (from contamination), vanadium, iron, titanium, silicon, calcium, sodium, potassium, chlorine and arsenic.

[0094] Preferably, the silicon content (in addition to that possibly present by the silica of the support) is less than 2% by weight and very preferably less than 1% by weight relative to the weight of the fines.

[0095] Preferably, the arsenic content is less than 2000 ppm by weight and most preferably less than 1000 ppm by weight relative to the weight of the fines.

[0096] Preferably, the content for each metal, nickel, vanadium, iron, is less than 1% by weight and most preferably less than 5000 ppm by weight relative to the weight of the fines.

[0097] Preferably, the fines are not contaminated, i.e., they contain less than 100 ppm by weight of silicon (in addition to that possibly present in the oxide support), less than 100 ppm by weight of sodium (in addition to that possibly present in the oxide support), less than 50 ppm by weight of arsenic, less than 50 ppm by weight of iron, less than 50 ppm by weight of chlorine, less than 2000 ppm by weight of vanadium and less than 2000 ppm by weight of nickel (contamination). This can be the case, in particular, when the fines come from a fresh or regenerated catalyst.

[0098] The fines used in the mixing in step a) of the process according to the invention can be wet or dry. When wet, the loss on ignition of the fines is between 0.1 and 50%, preferably between 0.5 and 40%, and most preferably between 1 and 30%.

[0099] All the contents of the different components of the fines are expressed on the basis of the weight of the dry fines. The inorganic oxide binder

[0100] According to the invention, the catalyst prepared by the process according to the invention may contain a binder. Said binder may advantageously be amorphous or crystalline. Preferably, said binder is advantageously selected from the group formed by the following oxides or their hydrated forms: alumina, silica, silica-alumina, clays, titanium dioxide, boron dioxide, and zirconia, alone or in mixtures. Preferably, said binder is alumina or an aluminum hydroxide, alone or in mixtures. Preferably, said binder is alumina in all its forms known to those skilled in the art, such as, for example, alpha, gamma, eta, and delta aluminas or hydroxides, such as boehmite, bayerite, or gibbsite. Said aluminas differ in their specific surface area and pore volume. Preferably, the inorganic oxide binder is alumina or boehmite.

[0101] The inorganic oxide binder used in the mixture in step a) of the process according to the invention can be wet or dry. When wet, the loss on ignition of the binder is between 5 and 80%, preferably between 6 and 70%, and preferably between 7 and 50%. Catalyst preparation

[0102] Step a) Mixing of fines and extrusion aid

[0103] According to step a), said fines are mixed with an extrusion aid agent, and optionally an inorganic oxide binder.

[0104] According to a preferred preparation method, the fines and the agent, and optionally the binder, can be mixed, without limitation, in the form of a powder, ground powder, suspension, or suspension that has undergone a deagglomeration treatment. Said fines and the agent, and optionally the binder, can advantageously be mixed by mechanical blending or by suspension at a concentration adjusted to the final content of fines and optionally binder targeted in the catalyst prepared according to the present invention.

[0105] The extrusion aid facilitates subsequent extrusion. The content of the extrusion aid is between 0.1 and 10 wt%, preferably between 0.1 and 5 wt%. and even more preferably between 0.1 and 3% by weight relative to the weight of the dry fines and the optional dry inorganic oxide binder introduced in step a).

[0106] The extrusion aid may be methylcellulose, for example Methocel™, cellulose, carboxymethylcellulose or carboxyethylcellulose. Preferably, the extrusion aid is methylcellulose (Methocel™).

[0107] Other extrusion shaping additives may also be added. Such additives are, for example, tall oil, xanthan gums, a surfactant, a flocculant such as polyacrylamides, carbon black, starches, stearic acid, polyacrylic alcohol, polyvinyl alcohol, biopolymers, glucose and polyethylene glycols.

[0108] The fines are introduced into the mixture in step a) such that the fines content is between 10% and 100% by weight of the catalyst obtained at the end of step e), preferably between 50% and 100% by weight, and most preferably between 75% and 100% by weight. The fines content in the catalyst obtained at the end of step e) is expressed on the basis of the dry weight of the fines.

[0109] Since the active phase is supplied by the fines in the catalyst obtained according to the process according to the invention, it is advantageous to integrate a high rate of fines incorporation into the catalyst in order to obtain high activity and / or to avoid having to reintroduce metals by impregnation thereafter.

[0110] The inorganic oxide binder is introduced into the mixture in step a) such that the inorganic oxide binder content is between 0% and 90% by weight of the catalyst obtained at the end of step e), preferably between 0% and 50% by weight, and most preferably between 0% and 25% by weight. The inorganic oxide binder content in the catalyst obtained at the end of step e) is expressed on a weight basis of the dry binder. The mixture in step a) may not contain any inorganic oxide binder. Step b) Peptization / kneading

[0111] According to step b), the mixture obtained in step a) is kneaded by adding an aqueous solution containing a carboxylic acid. A paste is thus obtained.

[0112] Carboxylic acid is a peptizing agent. The presence of a peptizing agent leads to the formation of a paste which is subsequently subjected to extrusion. The peptizing agent also minimizes macroporosity in the resulting catalyst and improves its mechanical strength.

[0113] The carboxylic acid is selected from formic acid, acetic acid, oxalic acid, citric acid, γ-ketovaleric acid alone or in mixture. Preferably, the carboxylic acid is citric acid.

[0114] The quantity of carboxylic acid added can advantageously be defined by a total acid content, expressed as a percentage relative to the weight of fines and possibly binder introduced in step a). The total acid content is between 0.1 and 20 wt%, preferably between 0.1 and 10 wt%, and most preferably between 1 and 9 wt%.

[0115] Water is optionally also introduced during step b), so that the loss on ignition of the mixture is between 20 and 80%, preferably between 30 and 70% and particularly preferably between 30 and 60%.

[0116] The mixing can advantageously be carried out by any conventional tool, commercially available.

[0117] The mixing time is generally between 1 minute and 1 hour, preferably between 5 and 30 minutes.

[0118] In an embodiment according to the invention, the aqueous solution containing a carboxylic acid further contains at least one organic compound having complexing (but not acidic) properties.

[0119] The organic compound (or at least one of them when there are several) exhibiting complexing properties may be selected from at least one of the following compounds: dimethylglyoxime, methyl acetoacetate, ethyl acetoacetate, ethyl lactate, methyl glycolate, ethyl glycolate, dimethyl malate, diethyl malate, dimethyl tartrate, diethyl tartrate, ethyl 3-hydroxybutanoate, ethyl 3-ethoxypropanoate, methyl 3-methoxypropanoate, methyl 3-(methylthio)propanoate, ethyl 3-(methylthio)propanoate, ethylene glycol, diethylene glycol, triethylene glycol, a polyethylene glycol (with a molecular weight between 200 and 1500) g / mol), propylene glycol, glycerol, 2-butoxyethanol, 2-(2-butoxyethoxy)ethanol, 2-(2-methoxyethoxy)ethanol, triethylene glycol dimethyl ether, a crown ether, acetophenone, 2,4-pentanedione, pentanone, glucose, fructose, sucrose,sorbitol, xylitol, mannitol, γ-valerolactone, propylene carbonate, octylamine, N-diethylformamide, N,N-dimethylformamide, N-methylformamide, N,N-dimethylacetamide, propanamide, λ-methyl-2-pyrrolidinone, tetramethylurea, N,N'-dimethylurea, acetonitrile, lactamide, furfurol, 2-furaldehyde, 5-hydroxymethylfurfural, ethyl 3-hydroxybutanoate, 2-hydroxyethyl acrylate, λ-vinyl-2-pyrrolidinone, N,N,N',N'-tetramethyl yltartramide, 3-hydroxypropionitrile, and N,N'-bis(2-hydroxyethyl)ethylenediamine.

[0120] According to a preferred embodiment, the organic compound exhibiting complexing properties is chosen from fructose, ethylene glycol, diethylene glycol and triethylene glycol.

[0121] The concentration of each organic compound exhibiting complexing properties of the aqueous solution containing a carboxylic acid is generally between 0.03 and 2 mol / L, preferably between 0.1 and 1.3 mol / L, and particularly preferably between 0.5 and 1 mol / L. Step c) Neutralization (optional)

[0122] A neutralization step c) can be carried out after the peptization step b) by adding to the mixture obtained in step b) a neutralizing agent chosen from an inorganic base or an organic base.

[0123] The inorganic base is chosen from sodium hydroxide, potassium hydroxide, and ammonia, alone or in mixtures, and the organic base is chosen from amines and quaternary ammonium compounds, alone or in mixtures. Preferably, the organic base is chosen from alkylethanolamines and ethoxylated alkylamines. The organic base is preferably used in aqueous solution. Most preferably, the neutralizing agent is an inorganic base, and preferably ammonia.

[0124] The amount of neutralizing agent can be defined by a neutralization rate expressed as a molar percentage of base relative to the number of moles of protons present in step b) and is between 1 and 100%. Preferably, the neutralization rate expressed as a molar percentage of base relative to the number of moles of protons is between 20 and 60%.

[0125] Water is optionally also introduced during the neutralization step, so that the loss on ignition of the mixture is between 20 and 80%, preferably between 30 and 70% and particularly preferably between 30 and 60%.

[0126] When the neutralization step by adding the neutralizing agent is carried out, the mixing is maintained under the conditions described above. Step d): Shaping by extrusion

[0127] According to step d), shaping is carried out by extrusion of the mixture obtained in step b) of peptization, or of the mixture obtained in step c) of neutralization when present, to obtain a solid.

[0128] Extrusion can advantageously be carried out using any conventional, commercially available tool. The mixture from step b) or c) is advantageously extruded through a die, for example, using a piston or a single or double screw extrusion die. This extrusion step can advantageously be carried out by any method known to those skilled in the art for obtaining a solid. The extrudates can be multilobed, for example, trilobed or quadrilobed. Step e) Drying

[0129] According to step e) of the process, the solid obtained in step d) is dried at a temperature below 200°C, advantageously between 50°C and 180°C, preferably between 70°C and 150°C, preferably between 80°C and 140°C, without calcining it subsequently, in order to obtain a catalyst.

[0130] The drying step can be carried out by any technique known to those skilled in the art. It is advantageously carried out at atmospheric pressure or reduced pressure. Preferably, this step is carried out at atmospheric pressure. It is advantageously carried out in a flow bed using air or any other hot gas. Preferably, when drying is carried out in a fixed bed, the gas used is either air or an inert gas such as argon or nitrogen. Most preferably, drying is carried out in a flow bed in the presence of nitrogen and / or air. Preferably, the drying step has a duration of between 5 minutes and 24 hours, preferably between 30 minutes and 10 hours, and most preferably between 1 hour and 8 hours.

[0131] The drying is carried out in such a way as to retain preferably at least 30% by weight of the carboxylic acid introduced during the peptization step, preferably this quantity is greater than 50% by weight and even more preferably greater than 70% by weight, calculated on the basis of the carbon remaining on the catalyst obtained.

[0132] It is important to emphasize that the catalyst obtained by the process according to the invention does not undergo calcination after drying in order to preserve at least part of the carboxylic acid in the catalyst. Calcination is understood here to mean heat treatment under a gas containing air or oxygen at a temperature greater than or equal to 200°C.

[0133] Step f) Introduction of active phase (optional)

[0134] Depending on the application of the catalyst and its target contents of metals from groups VIB and / or VIII, the process according to the invention may include a step f) of introducing one or more precursors of an active phase onto the catalyst obtained in step e). This may in particular be the case when the binder introduction rate is high.

[0135] Thus, according to the optional step f) of the preparation process according to the invention, at least one metal from group VIB and / or at least one metal from group VIII, and optionally phosphorus, and / or at least one organic compound comprising oxygen and / or nitrogen and / or sulfur, is brought into contact with said catalyst obtained after step e) of drying.

[0136] The group VIB metal and / or the group VIII metal introduced in this step f) may be the same as or different from the group VIB metal and the group VIII metal already introduced by the fines. A metal that was not present in the fines may be introduced.

[0137] The molar ratio of group VIII metal to group VIB metal in the final catalyst is generally between 0.1 and 0.8, preferably between 0.15 and 0.6.

[0138] Contacting at least one metal from group VIB and / or at least one metal from group VIII with said catalyst can advantageously be achieved by any A technique known to those skilled in the art, such as ion exchange, dry impregnation, excess impregnation, vapor deposition, etc. The contacting process may take place in one step or in several successive steps. According to a preferred method, said contacting step(s) is / are carried out by the so-called "dry" impregnation method well known to those skilled in the art by bringing into contact an impregnation solution containing a metal from Group VIII and / or a metal from Group VIB with said catalyst.

[0139] The contacting advantageously involves a precursor of said metals.

[0140] By way of example, molybdenum sources may include oxides and hydroxides, molybdic acids and their salts, in particular ammonium salts such as ammonium molybdate, ammonium heptamolybdate, phosphomolybdic acid (H3PMoi2O4o), and their salts, and possibly silicomolybdic acid (H4SiMoi2O4o) and its salts. Molybdenum sources may also include any heteropolycompound of the Keggin, lacunar Keggin, substituted Keggin, Dawson, Anderson, and Strandberg types, for example. Molybdenum trioxide and heteropolycompounds of the Keggin, lacunar Keggin, substituted Keggin, and Strandberg types are preferred.

[0141] The tungsten precursors that can be used are also well known to those skilled in the art. For example, tungsten sources include oxides and hydroxides, tungstic acids and their salts, in particular ammonium salts such as ammonium tungstate, ammonium metatungstate, phosphotungstic acid and their salts, and possibly silicotungstic acid (H4SiWi2O4O) and its salts. Tungsten sources can also be any heteropolycompound of the Keggin, lacunar Keggin, substituted Keggin, or Dawson type, for example. Ammonium oxides and salts such as ammonium metatungstate or heteropolyanions of the Keggin, lacunar Keggin, or substituted Keggin type are preferred.

[0142] The cobalt precursors that can be used are advantageously chosen from among oxides, hydroxides, hydroxycarbonates, carbonates and nitrates, for example. Cobalt hydroxide and cobalt carbonate are preferred.

[0143] Nickel precursors that can be used are advantageously chosen from oxides, hydroxides, hydroxycarbonates, carbonates and nitrates, for example.

[0144] Any impregnation solution described in the present invention may comprise any polar protic solvent known to those skilled in the art. Preferably, a polar protic solvent is used, for example, one chosen from the group consisting of methanol, ethanol, and water. Preferably, the solvent used in the impregnation solution is water.

[0145] According to another variant, the contacting step f) may also include contacting said catalyst obtained after the drying step e) with an impregnation solution containing phosphorus, in addition to the metal of group VIB and / or the metal of group VIII.

[0146] The total phosphorus to VIB group metal molar ratio in the catalyst is greater than or equal to 0.05, preferably greater than or equal to 0.07, preferably between 0.08 and 1, preferably between 0.1 and 0.9 and most preferably between 0.15 and 0.6.

[0147] The preferred phosphorus precursor is orthophosphoric acid H3PO4, but its salts and esters such as ammonium phosphates are also suitable. Phosphorus can also be introduced along with the element(s) of group VIB in the form of Keggin, lacunar Keggin, substituted Keggin, or Strandberg-type heteropolyanions.

[0148] According to yet another embodiment, the contacting step (f) may also include contacting said catalyst obtained after the drying step with an impregnation solution containing an organic compound containing oxygen and / or nitrogen and / or sulfur, in addition to the Group VIB metal, the Group VIII metal, and optionally phosphorus. The function of the additives or organic compounds is to increase the catalytic activity compared to the unadditized catalysts. Said organic compound is preferentially impregnated onto said catalyst after solubilization in aqueous or non-aqueous solution.

[0149] In this case, the total molar ratio of the organic compound per metal of group VIB in solution is between 0.01 and 5 mol / mol, preferably between 0.05 and 3 mol / mol, preferably between 0.05 and 2 mol / mol and most preferably between 0.1 and 1.5 mol / mol.

[0150] When several organic compounds are present, the different molar ratios apply to each of the organic compounds present.

[0151] Generally, the organic compound is chosen from a compound comprising one or more chemical functions chosen from a carboxylic, alcohol, thiol, thioether, sulfone, sulfoxide, ether, aldehyde, ketone, ester, carbonate, amine, nitrile, imide, oxime, urea and amide function, or a compound including a furanic ring or a sugar.

[0152] Preferably, it is selected from γ-valerolactone, 2-acetylbutyrolactone, triethylene glycol, diethylene glycol, ethylene glycol, ethylenediaminetetraacetic acid (EDTA), formic acid, acetic acid, oxalic acid, maleic acid, malonic acid, citric acid, gluconic acid, dimethyl succinate, glucose, fructose, sucrose, sorbitol, xylitol, γ-ketovaleric acid, dimethylformamide, β-methyl-2-pyrrolidinone, propylene carbonate, 2-methoxyethyl 3-oxobutanoate, bicine, tricine, 2-furaldehyde (also known as furfural), 5-hydroxymethylfurfural (also known as 5-(hydroxymethyl)-2-furaldehyde or 5-HMF), 2-acetylfuran, 5-methyl-2-furaldehyde, ascorbic acid, butyl lactate, ethyl 3-hydroxybutanoate, ethyl 3-ethoxypropanoate, 2-ethoxyethyl acetate, 2-butoxyethyl acetate, 2-hydroxyethyl acrylate, l-vinyl-2-pyrrolidinone, l,3-dimethyl-2-imidazolidinone, l-(2-hydroxyethyl)-2-pyrrolidinone, the l-(2-hydroxyethyl)-2,5-pyrrolidinedione, 5-methyl-2(3H)-furanone, l-methyl-2-piperidinone and 4-aminobutanoic acid.

[0153] Preferably, the organic compound is chosen from formic acid, acetic acid, oxalic acid, citric acid, γ-ketovaleric acid, fructose, ethylene glycol, diethylene glycol and triethylene glycol.

[0154] The organic compound introduced in this way may be identical or different from the carboxylic acid introduced during step b) of peptization and / or identical or different from the organic compound having complexing properties possibly introduced during step b) and maintained during drying in step e). Preferably it is identical.

[0155] The impregnation step has several implementation methods. They are distinguished in particular by the timing of the introduction of the organic compound, if present, which can be carried out either simultaneously with the impregnation of the metals (co-impregnation), afterward (post-impregnation), or before (pre-impregnation). Furthermore, the implementation methods can be combined.

[0156] Advantageously, after each impregnation step, the impregnated substrate is allowed to mature. Maturation allows the impregnation solution to disperse homogeneously within the substrate.

[0157] Any maturation step described in the present invention is advantageously carried out at atmospheric pressure, in a water-saturated atmosphere, and at a temperature between 17°C and 50°C, and preferably at ambient temperature. Generally, a maturation time of between ten minutes and forty-eight hours, and preferably between thirty minutes and six hours, is sufficient.

[0158] After the impregnation step(s) and the possible maturation step(s), the catalyst is generally dried at a temperature below 200°C, advantageously between 50°C and 180°C, preferably between 70°C and 150°C, most preferably between 75°C and 130°C, without further calcination, so as to obtain a dried catalyst.

[0159] The drying step can be carried out by any technique known to a person skilled in the art as described above.

[0160] According to one variant and advantageously when an organic compound is present, the drying is carried out in such a way as to retain preferably at least 30% by weight of the organic compound introduced during an impregnation step, preferably this quantity is greater than 50% by weight and even more preferably greater than 70% by weight, calculated on the basis of the carbon remaining on the catalyst.

[0161] As with drying step e), it is important to emphasize that the catalyst obtained at the end of step f) is not calcined after drying in order to preserve at least part of the carboxylic acid and possibly the organic compound with complexing properties introduced in step b), and possibly the organic compound containing oxygen and / or nitrogen and / or sulfur introduced in the optional step f) into the catalyst. Calcination is defined here as heat treatment under a gas containing air or oxygen at a temperature of 200°C or higher.

[0162] Before its use in a hydrotreating and / or hydrocracking reaction, it is advantageous to transform the catalyst obtained according to the process of the invention, optionally supplemented by impregnation with an active phase of a metal from group VIB and / or a metal from group VIII, phosphorus, and an organic compound, into a sulfide catalyst in order to form its active species. This activation or sulfidation step is carried out by methods well known to those skilled in the art, and advantageously under a sulfur-reducing atmosphere in the presence of hydrogen and hydrogen sulfide.

[0163] At the end of the drying step e) or after the possible introduction of the active phase of step f) of the process according to the invention, said catalyst is therefore advantageously subjected to a sulfidation step, without an intermediate calcination step.

[0164] Said catalyst is advantageously sulfided ex situ or in situ. The sulfiding agents are H2S gas, elemental sulfur, CS2, mercaptans, sulfides and / or polysulfides, hydrocarbon cuts with a boiling point below 400°C containing sulfur compounds, or any other sulfur-containing compound used for activating hydrocarbon feedstocks for the purpose of sulfiding the catalyst. Said sulfur-containing compounds are advantageously selected from alkyl disulfides such as, for example, dimethyl disulfide (DMDS), alkyl sulfides such as, for example, dimethyl sulfide, thiols such as, for example, n-butylmercaptan (or 1-butanethiol), and polysulfide compounds of the tertiononyl polysulfide type. The catalyst can also be sulfided by the sulfur contained in the feedstock to be desulfurized. Preferably, the catalyst is sulfided in situ in the presence of a sulfurizing agent and a hydrocarbon feedstock.Preferably, the catalyst is sulfided in situ in the presence of a hydrocarbon feedstock with added dimethyl disulfide. Characteristics of the catalyst obtained

[0165] The preparation process according to the present invention makes it possible to obtain a catalyst comprising at least one oxide support, at least one metal from Group VIII and / or at least one metal from Group VIB (derived from the fines and optionally introduced after the drying step e)), a carboxylic acid (introduced as a peptizing agent) and optionally phosphorus (derived from the fines or optionally introduced during step f)) and optionally another organic compound comprising oxygen and / or nitrogen and / or sulfur (derived from the fines or introduced during step f) or introduced in step b). The catalyst obtained according to the process of the invention may also include, without limitation, coke and / or sulfur, particularly when derived from the fines of a regenerated or spent catalyst.

[0166] The content of group VIII metal is between 0.5 and 50% by weight of group VIII metal oxide relative to the weight of the catalyst, preferably between 1.5 and 9% by weight, and preferably between 2 and 8% by weight.

[0167] The metal content of group VIB is between 2.5 and 40 wt% of oxide of group VIB metal relative to the weight of the catalyst, preferably between 8 and 35 wt%, most preferably between 10 and 30 wt%.

[0168] The molar ratio of group VIII metal to group VIB metal in the catalyst, when the latter contains both types of metals, is preferably between 0.1 and 0.8, preferably between 0.15 and 0.6 and even more preferably between 0.2 and 0.6 or between 0.3 and 0.5.

[0169] The phosphorus content is then preferably between 0.05 and 20% by weight expressed as P2O5 relative to the weight of the catalyst, preferably between 0.2 and 15% by weight expressed as P2O5, and most preferably between 0.3 and 8% by weight expressed as P2O5.

[0170] The phosphorus molar ratio to the element in group VIB is greater than or equal to 0.05, preferably greater than or equal to 0.07, preferably between 0.08 and 1, preferably between 0.01 and 0.9 and most preferably between 0.15 and 0.6.

[0171] The sulfur content may be between 0 and 15% by weight, expressed as an element relative to the weight of the catalyst, preferably between 1 and 12%, and most preferably between 2 and 10% by weight. Preferably, the catalyst contains little or no sulfur. The sulfur content is then preferably less than 5% by weight, preferably between 0.1% and 3% by weight, preferably between 0.1% and 2% by weight, and most preferably between 0.1% and 0.8% by weight. The catalyst may also be sulfur-free.

[0172] The coke content, expressed as a percentage by weight of the carbon element, may be between 0 and 20% by weight, preferably between 1.5 and 16% by weight, and in particular between 2 and 14% by weight relative to the weight of the catalyst. Preferably, the catalyst contains little or no coke. The coke content is then preferably less than 5% by weight, preferably between 0.1% and 4% by weight, preferably between 0.1% and 2% by weight, and particularly preferably between 0.1% and 1% by weight, or even between 0.1 and 0.5% by weight. The catalyst may also be coke-free.

[0173] The preparation process according to the present invention has in particular the advantage of leading to a catalyst having a very satisfactory mechanical resistance in relation to the porous volumes which characterize it, said resistance being materialized by the value of the grain-to-grain EGG crushing, of at least 0.4 daN / mm, preferably of at least 0.7 daN / mm, most preferably of at least 0.8 daN / mm.

[0174] The preparation process according to the present invention makes it possible to obtain a catalyst advantageously having a total pore volume, as measured by mercury porosimeter intrusion, of between 0.1 and 1.5 ml / g and preferably between 0.2 and 1.1 ml / g

[0175] The mesoporous volume of the catalyst prepared according to the invention, i.e. contained in the pores with a diameter between 2 and 50 nm, as measured by intrusion with a mercury porosimeter, is between 0.1 and 0.7 ml / g and preferably between 0.1 and 0.5 ml / g.

[0176] The macroporous volume of the catalyst prepared according to the invention, i.e. contained in the pores with a diameter greater than 50 nm, as measured by intrusion with a mercury porosimeter, is between 0 and 0.4 ml / g and preferably between 0 and 0.2 ml / g and very preferably between 0 and 0.1 ml / g, and particularly preferably between 0 and 0.08 ml / g.

[0177] The catalyst prepared according to the invention generally has a specific surface area of ​​between 5 and 400 m2 / g, preferably between 10 and 350 m2 / g, preferably between 40 and 350 m2 / g, most preferably between 150 and 340 m2 / g. Hydrotreating and / or hydrocracking process

[0178] The catalyst obtained according to the process of the invention can be used in hydrotreating and / or hydrocracking processes of hydrocarbon fractions and more particularly for hydrogenation, hydrodeazotation, hydrodearomatization, hydrodesulfurization, hydrodeoxygenation, hydrodemetallation or hydroconversion reactions of hydrocarbon feedstocks.

[0179] The process of hydrotreating and / or hydrocracking hydrocarbon cuts can be carried out in one or more reactors in series of the fixed bed type or of the bubbling bed type.

[0180] The hydrocarbon feedstock targeted by hydrotreatment and / or hydroconversion can be of different types. In particular, the feedstock may be of fossil origin or derived from the conversion of biomass or waste, either alone or in mixtures. The feedstocks that are treated, and in particular those listed below, generally contain heteroatoms such as sulfur, oxygen, and nitrogen, and, for heavy feedstocks, they most often also contain metals.

[0181] The fossil fuel feedstock is, in particular, a fraction derived from coal or hydrocarbons produced from natural gas, possibly in mixtures. It may also consist of heavy petroleum or synthetic fractions, for example, kerosene, gas oil, or distillates obtained by atmospheric and vacuum distillation to produce usable kerosene, gas oil, or vacuum distillate, either in the storage unit receiving products of the same type (a "pool") or to a downstream unit such as a catalytic cracking unit, where the feedstocks are "cracked" to produce shorter-chain hydrocarbons. It is common for the hydrotreating process to be, in fact, a preliminary step in the treatment of a feedstock by a hydroconversion / hydrocracking process.

[0182] The fossil-based feedstocks used in a hydrotreating process, in more detail, are for example gasoline, gas oil, vacuum gas oil, atmospheric residues, vacuum residues, atmospheric distillates, vacuum distillates, heavy fuel oils, oils, waxes and paraffins, used oils, residues or deasphalted crudes, feedstocks from thermal or catalytic conversion processes, taken alone or in mixtures.

[0183] The feedstock resulting from biomass conversion may advantageously be selected from vegetable oils, algae or algal oils, fish oils, used cooking oils, and fats of vegetable or animal origin; or mixtures of such feedstocks. Said vegetable oils may advantageously be crude or refined, wholly or partially, and derived from plants selected from rapeseed, sunflower, soybean, palm, olive, coconut, copra, castor, cottonseed, peanut, linseed, and crambe oils, and all oils derived, for example, from sunflower or rapeseed by genetic modification or hybridization, this list not being exhaustive. Said animal fats are advantageously selected from lard and fats composed of residues from the food industry or from the catering industry.Frying oils, various animal oils such as fish oil, tallow, and lard can also be used. Feed from biomass conversion can also be advantageously chosen from among the available options. methyl esters of fatty acids of vegetable and / or animal origin or methyl esters of fatty acids from used edible vegetable oils.

[0184] The feedstock resulting from biomass conversion can also be selected from feedstocks obtained from thermal or catalytic biomass conversion processes, such as oils produced from biomass, particularly lignocellulosic biomass, using various liquefaction methods, such as hydrothermal liquefaction or pyrolysis. The term "biomass" refers to material derived from recently living organisms, including plants, animals, and their by-products. The term "lignocellulosic biomass" refers to biomass derived from plants or their by-products. Lignocellulosic biomass is composed of carbohydrate polymers (cellulose, hemicellulose) and an aromatic polymer (lignin).

[0185] The feed from biomass conversion can also advantageously be chosen from feeds from the paper industry.

[0186] The feedstock from waste conversion can be a pyrolysis oil derived from plastics, tires, or solid recovered fuels (SRF). These oils are obtained by thermal pyrolysis, catalytic pyrolysis, or hydropyrolysis (pyrolysis in the presence of a catalyst and hydrogen).

[0187] The operating conditions used in the processes implementing the hydrotreating reactions of hydrocarbon feedstocks described above are generally as follows: the temperature is advantageously between 180 and 450°C, and preferably between 250 and 440°C, the pressure is advantageously between 0.5 and 30 MPa, and preferably between 1 and 18 MPa, the hourly volumetric rate is advantageously between 0.1 and 20 h 1 and preferably between 0.2 and 5 h 1, and the hydrogen / feed ratio expressed as volume of hydrogen, measured under normal temperature and pressure conditions, per volume of liquid feedstock is advantageously between 50 1 / 1 to 5000 1 / 1 and preferably 80 to 2000 1 / 1.

[0188] According to a first embodiment, the hydrotreating process is a hydrotreating process, and in particular a hydrodesulfurization (HDS) process, of a diesel fraction carried out in the presence of at least one catalyst obtained according to the invention. The hydrotreating process aims to eliminate the sulfur compounds present in the diesel fraction in order to meet current environmental standards, namely an authorized sulfur content of up to 10 ppm. It also makes it possible to reduce the aromatic and nitrogen content of the diesel fraction to be hydrotreated.

[0189] Said hydrotreated diesel cut contains from 0.02 to 5.0 wt% sulfur. It is advantageously obtained from direct distillation (or straight run diesel according to Anglo-Saxon terminology), from a coking unit, from a visbreaking unit (Anglo-Saxon), a steam cracking unit, a hydrotreating and / or hydrocracking unit for heavier feedstocks, and / or a fluid catalytic cracking unit. This diesel cut preferably contains at least 90% of the compounds with a boiling point between 250°C and 400°C at atmospheric pressure.

[0190] The hydrotreating process of said diesel cut is carried out under the following operating conditions: a temperature between 200 and 400°C, preferably between 300 and 380°C, a total pressure between 2 MPa and 10 MPa and more preferably between 3 MPa and 8 MPa with a hydrogen volume to hydrocarbon feed volume ratio, expressed as hydrogen volume, measured under normal temperature and pressure conditions, per liquid feed volume, between 100 and 600 liters per liter and more preferably between 200 and 400 liters per liter and a volumetric hourly (WH) rate between 1 and 10 h1, preferably between 2 and 8 h1. WH corresponds to the inverse of the contact time expressed in hours and is defined by the ratio of the volumetric flow rate of liquid hydrocarbon charge to the volume of catalyst charged in the reaction unit implementing the hydrotreatment process according to the invention.The reaction unit implementing the hydrotreating process of said diesel fraction is preferably operated in a fixed bed, moving bed or bubbling bed, preferably in a fixed bed.

[0191] According to a second embodiment, said hydrotreating and / or hydrocracking process is a hydrotreating (in particular hydrodesulfurization, hydrodeazotation, aromatic hydrogenation) and / or hydrocracking process of a distillate cut under vacuum carried out in the presence of at least one catalyst obtained according to the invention. Said hydrotreating and / or hydrocracking process, otherwise called a hydrocracking pretreatment process or hydrocracking process, aims, as the case may be, to remove sulfur, nitrogen, or aromatic compounds present in said distillate cut in order to perform pretreatment before conversion in catalytic cracking or hydroconversion processes, or to hydrocrack the distillate cut which may have been pretreated beforehand if necessary.

[0192] A wide variety of feedstocks can be treated by the vacuum hydrotreating and / or hydrocracking processes of distillates described above. They generally contain at least 20% by volume and often at least 80% by volume of compounds boiling above 340°C at atmospheric pressure. The feedstock may be, for example, vacuum distillates, as well as feedstocks from aromatic extraction units of lubricating oil bases or from solvent dewaxing of lubricating oil bases, and / or deasphalted oils, or the feedstock may be Deasphalted oil or paraffins from the Fischer-Tropsch process, or any mixture of the aforementioned feedstocks. Generally, the feedstocks have a boiling point (T5) above 340°C at atmospheric pressure, and preferably above 370°C at atmospheric pressure; that is, 95% of the compounds present in the feedstock have a boiling point above 340°C, and preferably above 370°C. The nitrogen content of the feedstocks treated in the processes according to the invention is usually greater than 200 ppm by weight, preferably between 500 and 10,000 ppm by weight. The sulfur content of the feedstocks treated in the processes according to the invention is usually between 0.01 and 5.0% by weight. The feedstock may optionally contain metals (for example, nickel and vanadium). The asphaltene content is generally less than 3,000 ppm by weight.

[0193] The catalyst obtained according to the invention is generally contacted, in the presence of hydrogen, with the feedstocks described above, at a temperature above 200°C, often between 250°C and 480°C, advantageously between 320°C and 450°C, preferably between 330°C and 435°C, under a pressure above 1 MPa, often between 2 and 25 MPa, preferably between 3 and 20 MPa, the volumetric velocity being between 0.1 and 20.0 h⁻¹ and preferably 0.1–6.0 h⁻¹, preferably 0.2–3.0 h⁻¹, and the quantity of hydrogen introduced is such that the volumetric ratio of liters of hydrogen to liters of hydrocarbon, expressed as volume of hydrogen, measured under normal temperature and pressure conditions, per volume of liquid feedstock, is between 80 and 5,000 1 / 1 and most often between 100 and 2,000 1 / 1.These operating conditions used in the processes according to the invention generally make it possible to achieve conversions per pass, in products having boiling points below 340°C at atmospheric pressure, and preferably below 370°C at atmospheric pressure, of more than 15% and even more preferably between 20 and 95%.

[0194] Vacuum hydrotreating and / or hydrocracking processes for distillates using the catalysts obtained according to the invention cover pressure and conversion ranges from mild hydrocracking to high-pressure hydrocracking. Mild hydrocracking is defined as hydrocracking that results in moderate conversions, generally less than 40%, and operates at low pressure, generally between 2 MPa and 6 MPa.

[0195] The catalyst obtained according to the invention can be used alone, in one or more fixed-bed catalytic beds, in one or more reactors, in a so-called one-stage hydrocracking scheme, with or without liquid recycling of the unconverted fraction, or in a so-called two-stage hydrocracking scheme, possibly in association with a hydrorefining catalyst located upstream or downstream of said catalyst.

[0196] According to a third embodiment, the hydrotreating and / or hydrocracking process is advantageously implemented as a pretreatment in a fluidized bed catalytic cracking (FCC) process. The operating conditions of the pretreatment, in terms of temperature range, pressure, hydrogen recycling rate, and hourly volumetric rate, are generally identical to those described above for vacuum hydrotreating and / or hydrocracking processes of distillates. The FCC process can be carried out in a conventional manner known to those skilled in the art under suitable cracking conditions to produce lower molecular weight hydrocarbon products. A summary description of catalytic cracking can be found, for example, in Ullman's Encyclopedia of Industrial Chemistry, Volume A, 18, 1991, pages 61 to 64.

[0197] According to a fourth mode of use, said hydrotreating and / or hydrocracking process according to the invention is a hydrotreating process (in particular hydrodesulfurization) of a gasoline cut in the presence of at least one catalyst obtained according to the invention.

[0198] Unlike other hydrotreating processes, hydrotreating (in particular hydrodesulfurization) gasoline must meet a dual antagonistic constraint: ensuring deep hydrodesulfurization of gasoline and limiting the hydrogenation of unsaturated compounds present in order to limit the loss of octane number.

[0199] The feedstock is generally a hydrocarbon fraction having a distillation range between 30 and 260°C. Preferably, this hydrocarbon fraction is a gasoline fraction. Most preferably, the gasoline fraction is an olefinic gasoline fraction obtained, for example, from a fluid catalytic cracking unit.

[0200] The hydrotreating process consists of bringing the hydrocarbon cut into contact with the catalyst and hydrogen under the following conditions: at a temperature between 200 and 400°C, preferably between 230 and 330°C, at a total pressure between 1 and 3 MPa, preferably between 1.5 and 2.5 MPa, at a Volumetric Hourly (WH), defined as the volumetric flow rate of charge relative to the volume of catalyst, between 1 and 10 h1, preferably between 2 and 6 h1 and at a hydrogen / gasoline charge volume ratio between 100 and 600 Nl / 1, preferably between 200 and 400 Nl / 1.

[0201] The hydrotreating process for gasoline can be carried out in one or more reactors in series of the fixed bed or bubbling bed type. If the process is implemented using at least two reactors in series, it is possible to provide a device for removing H2S from the effluent from the first hydrodesulfurization reactor before treating said effluent in the second hydrodesulfurization reactor.

[0202] Although the present invention relates to a process for preparing a catalyst intended for use in hydrotreating and / or hydrocracking units of hydrocarbons, it is understood that the process according to the invention applies to the preparation of any catalyst comprising at least one metal from group VIII and / or at least one metal from group VIB, and an oxide support, such as, for example, selective hydrogenation catalysts, hydrotreating catalysts for residues (for example carried out in a boiling bed) or Fischer-Tropsch catalysts.

[0203] Fines which do not have the same function as the catalyst prepared by the process according to the invention can also be used, as long as the fines and the catalyst produced have at least one metal in common (hydrotreating catalyst, hydrocracking catalyst, Fischer-Tropsch catalyst). Examples

[0204] We start from a spent catalyst called CoMoP, containing molybdenum, cobalt and phosphorus deposited on an alumina support used in a hydrotreating process. It has previously been regenerated under a flow of dry air at 450°C for 4 hours.

[0205] The regenerated catalyst contains molybdenum, phosphorus and cobalt. The composition of the catalyst is expressed in terms of oxides and referred to the mass of dry catalyst: 21.6 wt% of MoO3 (14.4 wt% of molybdenum), 3.7 wt% of CoO (2.9 wt% of cobalt, i.e. a molar ratio Co / Mo of 0.33) and 3.2 wt% of P2O5 (1.4 wt% of phosphorus, i.e. a molar ratio P / Mo of 0.3).

[0206] Example 1: Preparation of catalyst A according to the invention

[0207] To prepare catalyst A, the regenerated CoMo catalyst is ground to a particle size such that the D90 is equal to 30 µm. The fines are introduced with 3 wt% of Methocel™ into a closed vessel of a Brabender-type cam-arm mixer. A peptizing agent, citric acid (C6H8O7), is added to achieve an acid content of 10%. Water is also gradually added to achieve a loss on ignition (LOI) of 40%, the value being adjusted according to the formulation to obtain a homogeneous and cohesive paste. The paste is mixed for 15 min and then extruded using a piston extruder through a 1.8 mm diameter die mm. The resulting extradites are dried (16 hours at 80°C in a ventilated oven under air). The characteristics of the catalyst A obtained are given in Table 1.

[0208] Example 2: Non-compliant preparation of catalyst B

[0209] To prepare catalyst B, the regenerated CoMo catalyst is ground to a particle size such that the D90 is equal to 30 µm. The fines are introduced with 2 wt% of Methocel™ into a closed tank of a Brabender-type cam-arm mixer. A peptizing agent, nitric acid (HNO3), is added to achieve an acid content of 1%. Water is also gradually added to achieve a loss on ignition (LOI) of 40%, the value being adjusted according to the formulation to obtain a homogeneous and cohesive paste. The paste is mixed for 30 min and then extruded using a piston extruder through a 1.8 mm diameter die. The extrudates thus obtained are dried (16 hours at 80°C in an air-ventilated oven). The characteristics of the catalyst B obtained are given in Table 1.

[0210] Example 3: Preparation of non-conforming catalyst C

[0211] To prepare catalyst C, the regenerated CoMo catalyst is ground to obtain fines with a particle size such that D90 is equal to 70 µm. The fines are introduced with 2 wt% of Methocel™ into a closed vessel of a Brabender-type cam-arm mixer. A peptizing agent, citric acid (C6H8O7), is added to achieve an acid content of 6%. Water is also gradually added to achieve a loss on ignition (LOI) of 40%, the value being adjusted according to the formulation to obtain a homogeneous and cohesive paste. The paste is mixed for 10 min and then extruded using a piston extruder through a 1.8 mm diameter die. The resulting extrudates are dried (16 hours at 80°C in a ventilated oven under air) and then calcined at 450°C for 4 hours under dry air. The characteristics of the resulting catalyst C are given in Table 1.

[0212] Example 4: Preparation of catalyst D according to the invention

[0213] To prepare catalyst D, the regenerated CoMo catalyst is ground to obtain fines with a particle size such that D90 is equal to 60 µm. 27 g of fines are introduced, along with 9 g of alumina (binder) and 2 wt% of Methocel™, into a closed vessel of a Brabender-type cam-arm mixer. A peptizing agent, citric acid (C6H8O7), is added to achieve an acid content of 5%. Water is also gradually added to achieve a loss on ignition (LOI) of 47%, the value being adjusted according to the formulation to obtain a homogeneous and cohesive paste. The paste is mixed for 30 min, and then an ammonia solution is gradually introduced to neutralize 40% of the acidity and achieve a loss on ignition (LOI) of 49%. The dough is then kneaded for another 15 minutes and then extruded using a piston extruder through a 1.8 mm diameter die. The resulting extradites are dried for 16 hours at 80°C in a ventilated oven under air. The characteristics of the catalyst D obtained are given in Table 1.

[0214] Example 5: Preparation of non-conforming catalyst E

[0215] To prepare catalyst E, the regenerated CoMo catalyst is ground to a particle size such that the D90 is equal to 70 µm. 29 g of fines are introduced with 13 g of boehmite (binder) and 3 wt% of Methocel™ into a closed vessel of a Brabender-type cam-arm mixer. A peptizing agent, nitric acid (HNO3), is added to achieve an acid content of 3%. Water is also gradually added to achieve a loss on ignition (LOI) of 46%, the value being adjusted according to the formulation to obtain a homogeneous and cohesive paste. The paste is mixed for 30 min, then an ammonia solution is gradually introduced to neutralize 30% of the acidity and achieve a loss on ignition (LOI) of 48%. The dough is then kneaded for another 15 minutes and then extruded using a piston extruder through a 1.8 mm diameter die. The resulting extrudates are dried for 16 hours at 80°C in a ventilated oven.The characteristics of the catalyst E obtained are given in Table 1.

[0216] Example 6: Preparation of non-conforming catalyst F

[0217] To prepare catalyst F, the regenerated CoMo catalyst is ground to a particle size such that the D90 is equal to 70 µm. 16 g of fines are introduced with 22 g of boehmite (binder) and 3 wt% of Methocel™ into a closed vessel of a Brabender-type cam-arm mixer. A peptizing agent, citric acid (C6H8O7), is added to achieve an acid content of 4%. Water is also gradually added to achieve a loss on ignition (LOI) of 52%, the value being adjusted according to the formulation to obtain a homogeneous and cohesive paste. The paste is mixed for 30 min, then an ammonia solution is gradually introduced to neutralize 50% of the acidity and obtain a loss on ignition (LOI) of 54%. The dough is then kneaded for another 15 minutes and then extruded using a piston extruder through a 1.8 mm diameter die.The extrudates thus obtained are dried (16 hours at 80°C in a ventilated oven under air) then calcined at 450°C for 4 hours under dry air. The characteristics of the catalyst F obtained are given in Table 1.

[0218] Table 1 below summarizes the characteristics of the synthesized catalysts A to F.

[0219] [Tables 1] ABCDEF catalyst example according to non-compliant invention non-compliant according to non-compliant invention non-compliant peptizing agent citric acid nitric acid citric acid citric acid nitric acid citric acid Thermal treatment drying drying calcination drying drying calcination Total pore volume (mL / g) 0.41 0.44 0.41 0.60 0.45 0.47 Mesoporous volume (mL / g) 0.32 0.3 0.3 0.44 0.4 0.46 Mac roporous volume (m L / g) 0.09 0.14 0.11 0.16 0.05 0.01 SbET (HlVg) 160 150 160 200 190 260 EGG (daN / mm) 0.8 0.4 0.32 0.45 0.6 1.3

[0220] Example 7: Evaluation in hydrodesulfurization (HDS) of diesel fuel of catalysts A and D (according to the invention) and B, C, E and F (not according to the invention)

[0221] Catalysts A and D (according to the invention) and B, C, E and F (not according to the invention) were tested in diesel fuel hydrodesulfurization. The regenerated catalyst was also tested and serves as a reference.

[0222] The characteristics of the diesel fuel used are as follows: density at 15 °C = 0.8522 g / cm3, sulfur content = 1.44% by weight.

[0223] Simulated Distillation (ASTM D2887): PI: 155 °C 10%: 247 °C 50%: 315°C 90%: 392 °C PF: 444 °C

[0224] The test is carried out in a flow-through fixed-bed isothermal pilot reactor, with fluids flowing from bottom to top.

[0225] The catalysts are previously sulfided in situ at 350°C in the pressurized reactor using the test diesel fuel to which 2% by weight of dimethyl disulfide is added.

[0226] The hydrodesulfurization tests were conducted under the following operating conditions: a total pressure of 7 MPa, a catalyst volume of 30 cm3, a temperature of 330 to 360°C, with a hydrogen flow rate of 24 l / h and with a charging flow rate of 60 cm3 / h.

[0227] The catalytic performance of the tested catalysts is given in Table 2. It is expressed in degrees Celsius relative to the regenerated catalyst chosen as a reference: it corresponds to the temperature difference required to reach 50 ppm of sulfur in the effluent. A negative value means that the target sulfur content is reached at a lower temperature and that there is therefore an increase in activity.

[0228] [Tables2] Catalyst Dilution Peptization Agent Heat Treatment Delta T(°C) / Regenerated Catalyst Reference Regenerated Catalyst - - - 0.0 Invention A 100% fines citric acid drying -1.3 Invention D 75% fines + 25% alumina citric acid drying 2.4 Comparison B 100% fines nitric acid drying 1.2 Comparison E 75% fines + 25% boehmite nitric acid drying 9.2 Comparison C 100% fines citric acid calcination 1.9 Comparison F 50% fines + 50% boehmite citric acid calcination 16.6

[0229] Catalyst A (according to the invention) exhibits improved activity compared to a catalyst C prepared with a final calcination step or a catalyst B prepared from an inorganic acid.

[0230] Catalyst D (according to the invention) exhibits improved activity compared to a catalyst F prepared with a final calcination step or a catalyst E prepared from an inorganic acid.

Claims

Demands

1. A process for preparing a catalyst from catalyst fines comprising at least one metal from Group VIB and / or at least one metal from Group VIII, and an oxide support, said fines having a D90 size less than or equal to 500 micrometers, the process comprising at least the following steps: a) mixing said fines and an extrusion aid, and optionally an inorganic oxide binder, b) kneading the mixture obtained in step a) by adding an aqueous solution containing a carboxylic acid, c) optionally adding to said mixture obtained in step b) a neutralizing agent selected from an inorganic base and an organic base, d) shaping the mixture obtained in step b) or c) by extrusion to obtain a solid, e) drying the solid obtained in step d) at a temperature below 200°C, without subsequent calcination.

2. A method according to claim 1, wherein the D90 size of the fines is less than 300 micrometers.

3. A process according to any one of the preceding claims, wherein the fines content is between 10% and 100% relative to the weight of the catalyst prepared by the process according to the invention.

4. A process according to any one of the preceding claims, wherein the fines have a Group VIB metal content of between 5 and 40 wt% oxide of Group VIB metal and a Group VIII metal content of between 1 and 50 wt% oxide of Group VIII metal relative to the weight of the fines.

5. A method according to any one of the preceding claims, wherein the fine oxide support is selected from alumina, silica, silica-alumina, titanium oxide or magnesium oxide used alone or in mixture with alumina or silica-alumina.

6. A method according to any one of the preceding claims, wherein said inorganic oxide binder is present and is selected from the group formed by the following oxides or their hydrated forms: alumina, silica, silica-alumina, clays, titanium oxide, boron oxide and zirconia, taken alone or in mixture.

7. A process according to any one of the preceding claims, wherein the content of the extrusion aid is between 0.1 and 10% weight relative to the weight of the dry fines and the optional dry inorganic oxide binder introduced in step a).

8. A method according to any one of the preceding claims, wherein the extrusion aid agent is selected from methylcellulose, cellulose, carboxy-methyl-cellulose, carboxy-ethyl-cellulose.

9. A process according to any one of the preceding claims, wherein the carboxylic acid is selected from formic acid, acetic acid, oxalic acid, citric acid, γ-ketovaleric acid, alone or in mixture.

10. A process according to any one of the preceding claims, wherein the amount of carboxylic acid added is defined by a total acid content, expressed as a percentage relative to the weight of the dry fines and the optional dry inorganic oxide binder introduced in step a) and is between 0.1 and 20 wt%.

11. A method according to any one of the preceding claims, wherein the aqueous solution containing a carboxylic acid further contains at least one organic compound having complexing properties.

12. A process according to any one of the preceding claims, wherein when step c) is carried out, said mixture obtained in step b) is added a neutralizing agent selected from an inorganic base and an organic base, said inorganic base being selected from sodium hydroxide, potassium hydroxide, and ammonia, alone or in mixture and said organic base being selected from amines and quaternary ammonium compounds alone or in mixture.

13. A process according to any one of the preceding claims, wherein the amount of neutralizing agent is defined by a neutralization rate expressed as a base mole percentage relative to the number of moles of protons present in step b) and is between 1 and 100%.

14. A process according to any one of the preceding claims, wherein it comprises a step (f) in which at least one metal of Group VIB and / or at least one metal of Group VIII, and optionally phosphorus and / or at least one organic compound comprising oxygen and / or nitrogen and / or sulfur, is contacted with said catalyst obtained after drying step (e), the contact being followed by a drying stage at a temperature below 200°C, without subsequent calcination.

15. A process according to any one of the preceding claims, wherein said catalyst obtained after the drying step e) or after the step f) is subjected to a sulfidation step, without an intermediate calcination step.