WO2021121981A1

WO2021121981A1 - Method for preparing a hydrotreating and/or hydrocracking catalyst by co-mulling in a melt, and catalyst obtained in the use thereof

Info

Publication number: WO2021121981A1
Application number: PCT/EP2020/084176
Authority: WO
Inventors: Elodie Devers; Audrey BONDUELLE-SKRZYPCZAK; Mathieu Digne; Christophe Vallee
Original assignee: IFP Energies Nouvelles
Priority date: 2019-12-17
Filing date: 2020-12-01
Publication date: 2021-06-24
Also published as: FR3104466A1; FR3104466B1

Abstract

The invention relates to a method for preparing, by co-mulling in a melt, a catalyst comprising a metal from the group VIB and a medium comprising alumina, the method comprising the following steps: a) mixing an alumina precursor with an aqueous solution in order to obtain a paste, b) bringing the paste into contact with a hydrated metal acid comprising at least one metal from the group VIB, the melting point of the hydrated solid metal acid of which is between 20 and 100°C, the mass ratio between the metal acid and the porous medium being between 0.05 and 2.2, c) stirring the paste to a temperature between the melting temperature of the metal acid and 100°C, d) shaping the paste, e) drying, and f) calcining. The invention also relates to the catalyst and the use thereof in the field of hydrotreating and/or hydrocracking.

Description

PROCESS FOR PREPARING A HYDROTREATMENT AND / OR HYDROCRACKING CATALYST BY COMALAXING IN MOLTEN MEDIUM, CATALYST OBTAINED IN ITS USE

Field of the invention

The invention relates to a process for the preparation of a hydrotreatment and / or hydrocracking catalyst by co-mixing in a molten medium, the catalyst obtained by this process and its use in the field of hydrotreatment and / or hydrotreatment. hydrocracking.

State of the art

Usually, a hydrotreatment catalyst for hydrocarbon cuts aims to remove the sulfur or nitrogen compounds contained therein in order to bring, for example, a petroleum product to the required specifications (sulfur content, aromatics content etc ... ) for a given application (automotive fuel, gasoline or diesel, domestic fuel oil, jet fuel).

Conventional hydrotreatment catalysts generally include an oxide support and an active phase based on Group VI B and VIII metals in their oxide forms as well as phosphorus.

The preparation of these catalysts generally comprises an impregnation step using an impregnation solution containing metals and phosphorus on the support (also called conventional impregnation hereinafter), followed by drying and optionally d a calcination making it possible to obtain the active phase in their oxide forms. Prior to their use in a hydrotreatment and / or hydrocracking reaction, these catalysts are generally subjected to sulfurization to form the active species.

The hydrotreatment and / or hydrocracking catalysts based on metals from groups VI B and VIII prepared by a single impregnation step generally make it possible to achieve molybdenum and cobalt contents of respectively 30 and 7% by weight expressed as oxide. of metal relative to the weight of the catalyst, depending on the pore volume of the support used. When it is desired to prepare catalysts having a higher metal content, several successive impregnations are often necessary to obtain the metal content. desired metals, followed by at least one drying step, then optionally by a calcination step between each impregnation.

The preparation of hydrotreatment and / or hydrocracking catalysts based on metals from groups VI B and VIII having a high metal content by the conventional impregnation route thus involves a series of numerous steps and the use of solvent, such as water, which increases the associated manufacturing costs.

In addition, even by carrying out several successive impregnations, the maximum attainable molybdenum content is generally around 40% by weight expressed as molybdenum oxide relative to the weight of the catalyst, higher contents are not accessible with this technique.

Another preparation route is impregnation in a molten medium. This technique, particularly well described in the publication “Melt Infiltration: an Emerging Technique for the Preparation of Novel Functional Nanostructured Materials”, P.E. de Jongh, T.M. Eggenhuisen, Adv. Mater. 2013, 25, 6672-6690 is based on a one-step process based on the pressure-free and capillary infiltration of a molten liquid into a porous body.

Applied to the field of catalysis, impregnation in a molten medium consists in mixing a porous support with a solid metal salt having a relatively low melting point, in particular lower than its decomposition temperature, then heating the mixture to a temperature higher than the melting temperature of said metal salt in order to melt the salt in the support.

This technique is thus distinguished from conventional impregnation by several advantages, in particular by a simplified preparation. Indeed, it does not require preparation of solution or solvent because the metal precursors are used in the form of solids. Likewise, the catalyst obtained after heating the solid support / salt mixture does not need additional drying or calcination steps. In addition, a major advantage of impregnation in a molten medium is the fact that it is possible to obtain a catalyst with a very high metal content in a single step. This technique has the disadvantage of requiring a metal salt having a relatively low melting point, in particular lower than its decomposition temperature. Although such salts exist for the metals of group VIII, especially in the form of hydrated nitrate salt based on nickel or cobalt, there does not appear to be any group VI B salts which meet these low melting point criteria. . Indeed, salts based on a metal of group VIB tend to decompose before reaching their melting point.

However, there are hydrated metal acids based on a Group VIB metal which are in the form of powders and have a low melting point. However, these acids have the particularity of only melting in the presence of a sufficient amount of water. In other words, it is necessary to keep the water molecules of crystallization to ensure their fusion.

In order to prepare a catalyst heavily loaded with Group VIB metals in a few steps, it would be advantageous to introduce these acids into a support without the need to wet the support beforehand.

When preparing an alumina-based support from an alumina precursor, a first step is generally the shaping, that is to say the passage from a state of powder to a state of millimeter size support. Several shaping techniques exist depending on the application of the catalyst. The most commonly used technique is shaping by kneading / extrusion. Mixing involves peptizing an alumina precursor (often boehmite), that is, mixing the alumina precursor with a generally acidic solution in a mixer. The paste obtained is then extruded through a die to form extrudates of variable shape (cylinder, trilobe, quatrefoil, etc.), then the extrudates are dried and then calcined to form the alumina-based support.

The present invention is based on the fact that it is possible to introduce a hydrated metal acid based on a metal of group VIB in solid form into a paste obtained by kneading and subsequently to heat this mixture in order to melt hydrated metal acid. Indeed, the kneaded dough contains enough moisture so that the hydrated metal acid can keep the water molecules of crystallization to ensure its fusion. This technique will hereinafter be called “co-mixing in a molten medium” or “co-mixing in the melt”. Unlike known conventional co-mixing during which the active phase is provided by one or more solutions containing at least one metal from group VIB, co-mixing in a molten medium thus involves the introduction of the active phase in solid form into the paste followed by 'a heater.

The paste obtained after heating is then treated in a conventional manner by extrusion, drying and then calcination in order to obtain an alumina-based catalyst containing at least one metal from group VIB.

In this context, one of the objectives of the present invention is to provide a process for preparing a hydrotreatment and / or hydrocracking catalyst based on a group VIB metal prepared by co-mixing in a molten medium.

Objects of the invention

The invention relates to a process for preparing a hydrotreatment and / or hydrocracking catalyst comprising at least one metal from group VIB and a support comprising alumina, the content of metal from group VIB being between 5 and 55% by weight expressed as metal oxide from group VIB relative to the total weight of the catalyst, said process comprising the following steps: a) an alumina precursor is mixed with an aqueous solution, optionally containing an inorganic acid, in order to obtain a paste, b) said paste obtained in step a) is brought into contact with at least one hydrated metal acid comprising at least one metal from group VIB whose melting point of said hydrated metal acid is between 20 and 100 ° C. , to form a paste containing the hydrated metallic acid, the mass ratio between said metallic acid and said alumina precursor being between 0.05 and 2.2, c) the paste containing the hydrated metallic acid is heated with stirring obtained at the end of step b) at a temperature between the melting point of said metallic acid and 100 ° C, c ') optionally contacting said paste obtained in step c) with an aqueous solution containing a base, d) shaping the paste obtained in step c) or in step c'), e ) the shaped paste is dried at a temperature below 200 ° C to obtain a dried catalyst, f) the dried catalyst is calcined at a temperature between 200 and 1000 ° C.

The Applicant has in fact observed that the use of hydrated metal acid comprising at least one metal from group VI B and having a melting point of between 20 and 100 ° C makes it possible to introduce a metal from group VI B into a catalyst. by co-mixing in a molten medium.

The preparation process according to the invention thus exhibits the advantages of the molten medium, in particular the absence of any solution preparation or the use of solvent to introduce the active phase based on a metal from group VIB.

In addition, the preparation process according to the invention makes it possible to obtain a catalyst heavily loaded with metal from group VIB having in particular contents of metal from group VIB which are neither achievable by conventional impregnation using a solution of 'conventional impregnation, or by conventional co-mixing using an impregnation solution.

Thus, the catalyst obtained according to the preparation process according to the invention makes it possible to observe a catalytic activity in hydrotreatment and / or hydrocracking at least at the same level as a catalyst prepared by conventional co-mixing using a solution of impregnation with, however, a simplified preparation and the possibility of loading more metal from group VIB.

Alternatively, the hydrated metal acid is selected from hydrated phosphomolybdic acid, hydrated silicomolybdic acid, hydrated molybdosilicic acid, hydrated phosphotungstic acid and hydrated silicotungstic acid.

According to one variant, in step a) the alumina precursor is boehmite. According to one variant, in step a), a silicon precursor is also added to the mixture.

Alternatively, in step a) the acid is selected from nitric acid, hydrochloric acid, sulfuric acid and phosphoric acid. Alternatively, in step c ′) the base is chosen from ammonia, a mono-alkylamine, a dialkylamine, a tri-alkylamine, a tetra-alkylammonium hydroxide.

According to one variant, step b) further comprises bringing into contact with at least one metal salt comprising at least one metal from group VIII whose melting point of said metal salt is between 20 and 100 ° C, the molar ratio (metal of group VI II) / (metal of group VI B) being between 0.1 and 0.8.

According to one variant, said metal salt is a hydrated nitrate salt. According to a preferred variant, said metal salt is chosen from nickel nitrate hexahydrate, and cobalt nitrate hexahydrate, taken alone or as a mixture.

Alternatively, step b) further comprises contacting with phosphoric acid, the phosphorus / (group VIB metal) molar ratio being between 0.08 and 1.

According to one variant, step b) further comprises bringing into contact with an organic compound comprising oxygen and / or nitrogen and / or sulfur, the melting point of said organic compound of which is between 20 and 100 ° C, the organic compound / group VIB metal molar ratio being between 0.01 and 5.

According to this variant, the organic compound is chosen from maleic acid, sorbitol, xylitol, g-ketovaleric acid, 5-hydroxymethylfurfural and 1, 3-dimethyl-2-imidazolidinone.

According to one variant, after step f) an impregnation step g) is carried out using an impregnation solution and in which said catalyst is brought into contact with an impregnation solution comprising a metal from group VIB and / or a metal from group VIII and / or phosphorus and / or an organic compound comprising oxygen and / or nitrogen and / or sulfur, followed by a drying step h) at a temperature below 200 ° C and optionally a calcination step i) at a temperature between 200 ° C and 600 ° C under an inert atmosphere or under an atmosphere containing oxygen.

According to this variant, the organic compound is chosen from g-valerolactone, 2-acetylbutyrolactone, triethylene glycol, diethylene glycol, ethylene glycol, ethylenediaminetetra-acetic acid (EDTA), maleic acid, malonic acid, citric acid, gluconic acid, dimethyl succinate, glucose, fructose, sucrose, sorbitol, xylitol, g-ketovaleric acid, dimethylformamide, 1-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, acetate 2-ethoxyethyl, 2-butoxyethyl acetate, 2-hydroxyethyl acrylate, 1-vinyl-2-pyrrolidinone, 1, 3-dimethyl-2-imidazolidinone, 1- (2-hydroxyethyl) -2-pyrrolidinone, 1- (2-hydroxyethyl) -2,5-pyrrolidinedione, 5-methyl-2 (3H) - furanone, 1-methyl-2-piperidinone and l 4-aminobutanoic acid.

Alternatively, the catalyst is subjected to a sulfurization step after step f) or after optional steps h) or i).

The invention also relates to the catalyst obtained by the preparation process and its use in a hydrotreatment and / or hydrocracking process.

Description of the invention

The invention relates to a process for preparing a hydrotreatment and / or hydrocracking catalyst comprising at least one metal from group VI B and a support comprising alumina, the content of metal from group VIB being between 5 and 55% by weight expressed as group VIB metal oxide relative to the total weight of the catalyst, said process comprising the following steps: a) an alumina precursor is mixed with an aqueous solution, optionally containing an inorganic acid, in order to obtain a paste, b) said paste obtained in step a) is brought into contact with at least one hydrated metal acid comprising at least one metal from group VI B whose melting point of said hydrated metal acid is between 20 and 100 ° C, to forming a paste containing the hydrated metallic acid, the mass ratio between said metallic acid and said alumina precursor being between 0.05 and 2.2, c) the paste containing the hydrated metallic acid obtained is heated with stirring at after step b) at a temperature between the melting point of said metal acid and 100 ° C, c ') optionally contacting said paste obtained in step c) with an aqueous solution containing a base , d) the paste obtained in step c) or in step c ') is shaped, e) the shaped paste is dried at a temperature below 200 ° C to obtain a dried catalyst, f) the dried catalyst is calcined at a temperature between 200 and 1000 ° C.

Step a): Mixing the alumina precursor with an aqueous solution (peptization)

According to step a) of the preparation process according to the invention, an alumina precursor is mixed with an aqueous solution, optionally containing an inorganic acid, in order to obtain a paste.

The alumina precursor, often also called alumina gel, can be chosen from boehmite, gibbsite, bayerite or diaspore, alone or as a mixture. Preferably, the alumina precursor contains at least 50% by weight of AIOOH boehmite relative to the total weight of the alumina precursor. Most preferably, the alumina precursor is boehmite.

The alumina precursor used in step a) can be obtained according to various embodiments. Both precipitation and sol-gel synthesis are the most common methods used to produce boehmite. The alumina precursor used in step a) can contain an inorganic acid. The amount of acid contained in the alumina precursor is between 0 and 6%, expressed in mass of acid / mass of Al ₂ 0.

The alumina precursor, which is in powder form, is mixed with an aqueous solution optionally containing an inorganic acid. The inorganic acid can be selected from nitric acid, hydrochloric acid, sulfuric acid and phosphoric acid. Preferably nitric acid is used.

The amount of inorganic acid added is between 0 and 20%, preferably 0 and 10%, expressed in mass of acid / mass of Al C>.

Step a) of mixing is advantageously carried out by kneading. Step a) advantageously takes place in a mixer, for example a Z-arm mixer well known to those skilled in the art. The alumina precursor is placed in the mixer bowl. Then the aqueous solution possibly containing the inorganic acid is added to the syringe.

The speed of rotation of said mixer is generally between 0.5 and 200 revolutions per minute, preferably between 5 and 100 revolutions per minute.

The mixing time is generally between 2 minutes and 180 minutes, preferably between 5 minutes and 90 minutes.

Mixing step a) can be carried out at a temperature between 5 ° C and 100 ° C, preferably between 15 ° C and 60 ° C. It is preferably carried out at room temperature.

Any other element, for example silica in the form of a solution or emulsion of silicic precursor can be introduced at the time of this step a). The sources of silicon are well known to those skilled in the art. Mention may be made, by way of example, of silicic acid, silica in powder form or in colloidal form (silica sol), tetraethylorthosilicate Si (OEt) ₄ . The introduction of a silica precursor makes it possible to obtain a silica-alumina support.

Likewise, all sources of zeolite can be incorporated. Preferably, the zeolite is chosen from the group FAU, BEA, ISV, IWR, IWW, MEI, UWY and preferably, the zeolite is chosen from the group FAU and BEA, such as zeolite Y and / or beta, and particularly preferably such as USY and / or beta zeolite. Step b): Bringing the metallic acid into contact with the paste obtained in step a)

According to step b) of the preparation process according to the invention, said paste obtained in step a) is brought into contact with at least one hydrated metallic acid comprising at least one metal from group VI B, the melting point of which of said said paste. hydrated metallic acid is between 20 and 100 ° C, to form a paste containing hydrated metallic acid, the mass ratio between said metallic acid and said alumina precursor being between 0.05 and 2.2.

The hydrated metal acid should have a relatively low melting point, especially below its decomposition temperature. The melting point of hydrated metal acid is between 20 and 100 ° C, and preferably between 50 and 90 ° C.

The hydrated metal acid comprises at least one metal from Group VIB. The group VI B metal present in the acid is preferably chosen from molybdenum and tungsten.

The hydrated metal acid can additionally include phosphorus and silicon.

The metal acid can be an acid of a Keggin type heteropolyanion.

The hydrated metal acid is preferably chosen from hydrated phosphomolybdic acid (H3PM012O40, 28H2O, melting point T = 85 ° C), hydrated silicomolybdic acid (H SiMoi20 ₄ o, XH 0, melting point T = 47 -55 ° C), hydrated molybdosilicic acid (HeMoi ₂ 0 _4i Si, XH2O, melting point T = 45-70 ° C), hydrated phosphotungstic acid (H ₃ PW _I2 O ₄₀ , 28H ₂ 0, point melting point T = 89 ° C), hydrated silicotungstic acid (H SiWi ₂ 0 ₄ o, XH ₂ 0, melting point T = 53 ° C).

The mass ratio between said hydrated metal acid and said alumina precursor is between 0.05 and 2.2, preferably between 0.1 and 2.0.

In this step, the hydrated metallic acid is in solid form, that is to say that the hydrated metallic acid is brought into contact with the paste of step a) at a temperature below the melting temperature of said hydrated metallic acid. Step b) is preferably carried out at room temperature. According to step b), the contacting of said paste and the hydrated metal acid can be done by any method known to those skilled in the art. Preferably, the contacting is carried out by adding the hydrated metal acid to said paste in a mixer as described in step a).

The speed of rotation of said mixer is generally between 0.5 and 200 revolutions / minute, preferably between 5 and 100 revolutions per minute. It can be the same or different to the speed used in step a). Usually it is the same.

The mixing time is generally between 2 and 180 minutes, preferably between 2 and 90 minutes. It can be the same or different from the mixing time in step a).

According to a first variant, step b) consists of bringing said paste obtained in step a) into contact with at least one hydrated metallic acid comprising at least one metal from group VI B, the melting point of which of said metallic acid hydrated is between 20 and 100 ° C, to form a paste containing hydrated metal acid, the mass ratio between said metal acid and said alumina precursor being between 0.05 and 2.2.

Although the addition of other solid compounds to the catalyst obtained according to the preparation process of the invention after step f) is not necessary to obtain a catalytic activity close to those of catalysts according to the state of the art (prepared by co-mixing with the aid of a solution), it may be advantageous in certain cases to add other solid compounds to the solid mixture obtained in step b). Such compounds can in particular be a metal salt comprising at least one metal from group VIII, phosphoric acid or else an organic compound.

Thus, according to a second variant, step b) further comprises bringing into contact with at least one metal salt comprising at least one metal from group VIII whose melting point of said metal salt is between 20 and 100 ° C, the molar ratio (metal of group VI I l) / (metal of group VI B) being between 0.1 and 0.8.

The metal salt must have a relatively low melting point, especially lower than its decomposition temperature. The melting point of the metal salt is between 20 and 100 ° C, and preferably between 40 and 60 ° C. The metal salt comprises at least one metal from group VIII. The group VIII metal present in the salt is preferably chosen from nickel and cobalt.

Preferably, the metal salt is hydrated. Preferably, the metal salt is a hydrated nitrate salt. Preferably, the metal salt is chosen from nickel nitrate hexahydrate (Ni (NC> ₃ ) ₂ , 6H ₂ O, melting point T = 56.7 ° C) and cobalt nitrate hexahydrate (Co (N0 ₃ ) ₂ , 6H ₂ O, melting point T = 55.0 ° C), taken alone or as a mixture.

The molar ratio (metal of group VIII) / (metal of group VI B) is generally between 0.1 and 0.8, preferably between 0.15 and 0.6.

Preferably, the combination of the metals nickel-molybdenum, cobalt-molybdenum, nickel-tungsten, nickel-molybdenum-tungsten and nickel-cobalt-molybdenum and very preferably the active phase consists of cobalt and molybdenum, of nickel and molybdenum, nickel and tungsten or a nickel-molybdenum-tungsten combination.

It is well known that it is advantageous to add phosphorus to hydrotreating and / or hydrocracking catalysts. In fact, phosphorus has no catalytic character but increases the catalytic activity of the active phase by the formation of heteropolyanions which increases the dispersion of the elements in the support.

When hydrated phosphomolybdic acid or hydrated phosphotungstic acid is used as the metal acid hydrate, phosphorus is introduced into the catalyst along with the metal acid hydrate. In the case of hydrated phosphomolybdic acid, the P / Mo ratio is 0.08. In the case of hydrated phosphotungstic acid, the molar ratio of P / W is 0.08.

When it is desired to increase the molar ratio P / (metal from group VIB) in order to ultimately increase the catalytic activity, it is possible to add to the paste obtained in step a) a phosphorus compound in solid form, in particular the acid phosphoric. Phosphoric acid has a melting point of 42 ° C. Thus, according to a third variant, step b) further comprises bringing into contact with phosphoric acid. The phosphorus / (group VI B metal) molar ratio is generally between 0.08 and 1, preferably between 0.1 and 0.9, and very preferably between 0.15 and 0.8.

The addition of an organic compound to the hydrotreatment and / or hydrocracking catalysts to improve their activity has been recommended by those skilled in the art, in particular for catalysts which have been prepared by impregnation using an impregnation solution followed by drying without subsequent calcination. These catalysts are often called “additivated dried catalysts”. The introduction of an organic compound makes it possible to increase the dispersion of the active phase. The addition of an organic compound can also be carried out in the preparation process according to the invention when the organic compound is in solid form.

Thus, according to a fourth variant, step b) further comprises bringing into contact with an organic compound comprising oxygen and / or nitrogen and / or sulfur, the melting point of said organic compound of which is within between 20 and 100 ° C.

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 function, urea and amide or else compounds including a furan ring or also sugars.

Among the organic compounds comprising oxygen and / or nitrogen and / or sulfur and having a melting point of between 20 and 100 ° C, maleic acid, sorbitol, xylitol will preferably be chosen. , g-ketovaleric acid, 5-hydroxymethylfurfural (also known as 5- (hydroxymethyl) -2-furaldehyde or 5-HMF), 1, 3-dimethyl-2-imidazolidinone.

The organic compound / metal of group VI B molar ratio (contained in the hydrated metal acid) 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 very preferably between 0.1 and 1.5 mol / mol. After step b), a paste is thus obtained which comprises at least one metal from group VI B in the form of hydrated metallic acid and an alumina precursor. It may also additionally contain at least one metal from group VIII in the form of a metal salt and / or phosphoric acid and / or an organic compound comprising oxygen and / or nitrogen and / or sulfur.

Step c): Heating with stirring

According to step c) of the preparation process according to the invention, the paste containing the hydrated metallic acid obtained at the end of step b) is heated with stirring to a temperature between the melting point of said metallic acid and 100 ° C.

Step c) is advantageously carried out at atmospheric pressure. Step c) is generally carried out between 5 minutes and 12 hours, preferably between 5 minutes and 4 hours.

According to step c), the stirring (mechanical homogenization) of the mixture can be carried out by any method known to those skilled in the art. Preferably, convective mixers, drum mixers or static mixers can be used. Very preferably, step c) is carried out in a mixer as described in step a). The speed of rotation of said mixer is generally between 0.5 and 200 revolutions / minute, preferably between 5 and 100 revolutions per minute. It can be the same or different to the speed used in step a). Usually it is the same.

Step c '): Adding a basic solution (optional)

According to step c ’) of the preparation process according to the invention, said paste obtained in step c) is optionally contacted with an aqueous solution containing a base.

The base is selected from ammonia, mono-alkylamine, dialkylamine, trialkylamine, tetraalkylammonium hydroxide.

The amount of base added is such as to partially or totally neutralize the paste. The molar ratio: “number of moles of base added in step c ′) divided by number of moles of acid present in step a)” is generally between 0.1 and 2, preferably between 0.4 and 1. The contacting can be done by any method known to those skilled in the art. Preferably, convective mixers, drum mixers or static mixers can be used. Very preferably, step c ′) is carried out in a mixer as described in step a). The speed of rotation of said mixer is generally between 0.5 and 200 revolutions / minute, preferably between 5 and 100 revolutions per minute. It can be identical or different to the speed used in step a) or c). Usually it is the same.

Step c ’) can be carried out at a temperature between 5 ° C and 100 ° C, preferably between 15 ° C and 60 ° C. It is preferably carried out at room temperature.

Step d): Formatting

According to step d) of the process according to the invention, the paste obtained in step c) or optionally in step c ’) is shaped.

The shaping can be carried out using any technique known to those skilled in the art. It is generally carried out by extrusion.

Preferably, said paste obtained in step c) is shaped by extrusion in the form of extrudates with a diameter generally between 0.5 and 10 mm and preferably 0.8 and 3.2 mm and in a particularly preferred between 1.0 and 2.5 mm.

The shape of the extrudates can be cylindrical, three-lobed or four-lobed.

In a preferred embodiment, the catalyst is composed of trilobal or quadrilobed extrudates of size between 1.0 and 2.5 mm in diameter.

Step e): Drying

According to step e) of the process according to the invention, the shaped paste is dried at a temperature below 200 ° C to obtain a dried catalyst.

Step e) of drying is carried out at a temperature below 200 ° C, advantageously between 100 ° C and below 200 ° C, preferably between 50 ° C and 180 ° C, more preferably between 70 ° C and 150 ° C, very preferably between 75 ° C and 130 ° C. The drying temperature of step e) is generally higher than the heating temperature of step c). Preferably, the drying temperature of step e) is at least 10 ° C. higher than the heating temperature of step c).

The drying step is preferably carried out under an inert atmosphere or under an atmosphere containing oxygen.

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 at reduced pressure. Preferably, this step is carried out at atmospheric pressure. It is advantageously carried out in a crossed bed using air or any other hot gas. Preferably, when the drying is carried out in a fixed bed, the gas used is either air or an inert gas such as argon or nitrogen. Very preferably, the drying is carried out in a crossed bed in the presence of nitrogen and / or air. Preferably, the drying step has a duration of between 5 minutes and 4 hours, preferably between 30 minutes and 4 hours and very preferably between 1 hour and 3 hours.

Step f): calcination

According to step f) of the process according to the invention, the dried catalyst is calcined at a temperature between 200 and 1000 ° C.

Calcination step f) is carried out at a temperature between 200 and 1000 ° C, preferably between 300 and 900 ° C and even more preferably between 500 ° C and 850 ° C.

Preferably, the calcination step has a duration of between 0.5 hours and 16 hours, preferably between 1 hour and 5 hours.

It is generally carried out under an inert atmosphere (eg nitrogen) or under an atmosphere containing oxygen (eg air).

It can be performed in the presence of an air flow containing up to 60% water volume. If water is added, contact with water vapor can take place at atmospheric pressure (also called steaming according to English terminology). In the case of steaming, the water content is preferably between 150 and 900 grams per kilogram of dry air, and even more preferably between 250 and 650 grams per kilogram of dry air.

Said calcination step f) allows the transition from the alumina precursor to the final alumina. After this treatment, the active phase is thus in oxide form, the heteropolyanions are thus transformed into oxides. Likewise, the catalyst contains very little or no organic compound when it has been calcined. However, the introduction of the organic compound during its preparation made it possible to increase the dispersion of the active phase, thus leading to a more active catalyst.

Step g) of impregnation using an impregnation solution via post-impregnation (optional)

According to a variant, it may be advantageous in certain cases to add to the catalyst obtained according to step f) of the preparation process according to the invention, at least one of the additional metal precursors by impregnation with a solution of d. 'impregnation (classic post impregnation). It is also possible to add phosphorus or an organic compound.

This conventional impregnation step has the advantage of being able to use metal precursors or organic compounds which are not accessible via the molten medium technique (because in liquid form or having too high a melting point).

Thus, according to one variant, the calcination step f) can be followed by an impregnation step g) using an impregnation solution and in which said catalyst is brought into contact with a solution of impregnation comprising a metal from group VIB and / or a metal from group VIII and / or phosphorus and / or an organic compound comprising oxygen and / or nitrogen and / or sulfur.

In this case, the metal from group VIB, when it is introduced, is preferably chosen from molybdenum and tungsten. The metal from group VIII when it is introduced is preferably chosen from cobalt, nickel and a mixture of these two metals. Preferably, the combination of the metals nickel-molybdenum, cobalt-molybdenum, nickel-tungsten, nickel-molybdenum-tungsten and nickel-cobalt-molybdenum and very preferred, the active phase consists of cobalt and molybdenum, nickel and molybdenum, nickel and tungsten or a nickel-molybdenum-tungsten combination.

The group VIB metal introduced and / or the group VIII metal introduced may or may not be identical to the metals already present in the catalyst from step f).

By way of example, among the sources of molybdenum, use may be made of oxides and hydroxides, molybdic acids and their salts, in particular ammonium salts such as ammonium molybdate, ammonium heptamolybdate, phosphomolybdic acid (H ₃ PM0 ₁₂ O ₄₀ ), and their salts, and optionally silicomolybdic acid (H SiMoi ₂ 0 ₄ o) and its salts. The sources of molybdenum can also be any heteropolycompound such as Keggin, Lacunar Keggin, substituted Keggin, Dawson, Anderson, Strandberg, for example. Molybdenum trioxide and heteropolycompounds of Keggin, lacunar Keggin, substituted Keggin and Strandberg type are preferably used.

The tungsten precursors which can be used are also well known to those skilled in the art. For example, among the sources of tungsten, it is possible to use oxides and hydroxides, tungstic acids and their salts, in particular ammonium salts such as ammonium tungstate, ammonium metatungstate, phosphotungstic acid and theirs. salts, and optionally silicotungstic acid (H ₄ S1W ₁₂ O ₄₀ ) and its salts. The sources of tungsten can also be any heteropolycompound such as Keggin, lacunar Keggin, substituted Keggin, Dawson, for example. Oxides and ammonium salts such as ammonium metatungstate or heteropolyanions of the Keggin, lacunar Keggin or substituted Keggin type are preferably used.

The cobalt precursors which can be used are advantageously chosen from oxides, hydroxides, hydroxycarbonates, carbonates and nitrates, for example. Cobalt hydroxide and cobalt carbonate are preferably used.

The nickel precursors which can be used are advantageously chosen from oxides, hydroxides, hydroxycarbonates, carbonates and nitrates, for example. Nickel hydroxide and nickel hydroxycarbonate are preferably used.

In this case, the molar ratio (metal from group VIII) / (metal from group VIB) is generally between 0.1 and 0.8, preferably between 0.15 and 0.6. Phosphorus can also be introduced into the impregnation solution.

The preferred phosphorus precursor is orthophosphoric acid H ₃ PO ₄ , but its salts and esters such as ammonium phosphates are also suitable. The phosphorus can also be introduced at the same time as the metal (s) / metals of group VI B in the form of heteropolyanions of Keggin, lacunar Keggin, substituted Keggin or of the Strandberg type.

In this case, the molar ratio of the phosphorus added per metal from group VIB is between 0.1 and 2.5 mol / mol, preferably between 0.1 and 2.0 mol / mol, and even more preferably between 0.1 and 1.0 mol / mol.

An organic compound comprising oxygen and / or nitrogen and / or sulfur can also be introduced into the impregnation solution.

The function of additives or organic compounds is to increase the catalytic activity compared to catalysts without additives. Said organic compound is preferably impregnated on said catalyst after solubilization in aqueous or non-aqueous solution.

The organic compound containing oxygen can be one or more chosen from compounds comprising one or more chemical functions chosen from a carboxylic, alcohol, ether, aldehyde, ketone, ester or carbonate function or else compounds including a furan ring. or even sugars. By way of example, the organic compound containing oxygen can be one or more chosen from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, a polyethylene glycol (with a molecular weight of between 200 and 1500 g / mol), propylene glycol, 2-butoxyethanol, 2- (2-butoxyethoxy) ethanol, 2- (2-methoxyethoxy) ethanol, triethylene glycoldimethyl ether, glycerol, acetophenone, 2,4-pentanedione, pentanone, acetic acid, maleic acid, malic acid, malonic acid, oxalic acid, gluconic acid, acid tartaric acid, citric acid, g-ketovaleric acid, a C1-C4 dialkyl succinate, and more particularly dimethyl succinate, methyl acetoacetate, ethyl acetoacetate, 2- 3-oxobutanoate methoxyethyl, 2-methacryloyloxyethyl 3-oxobutanoate, dibenzofuran, crown ether, orthophthalic acid, glucose, fructose, sucrose, sorbitol, xylitol, y-valerolactone, 2-acetylbutyrolactone, carbonate propylene, 2-furaldehyde (also known as furfural), 5-hydroxymethylfurfural (also known as 5- (hydroxymethyl) -2-furaldehyde or 5-HMF), 2-acetylfuran, 5-methyl -2-furaldehyde, methyl 2-furoate, furfuryl alcohol (also known as furfuranol), furfuryl acetate, ascorbic acid, butyl lactate, butyl butyryllactate, 3-hydroxybutanoate ethyl, ethyl 3-ethoxypropanoate, methyl 3-methoxypropanoate, 2-ethoxyethyl acetate, 2-butoxy acetate ethyl, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and 5-methyl-2 (3H) -furanone.

The organic compound containing nitrogen can be one or more chosen from compounds comprising one or more chemical functions chosen from an amine or nitrile function. By way of example, the organic compound containing nitrogen can be one or more chosen from the group consisting of ethylenediamine, diethylenetriamine, hexamethylenediamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, acetonitrile , octylamine, guanidine or a carbazole.

The organic compound containing oxygen and nitrogen can be one or more chosen from compounds comprising one or more chemical functions chosen from a carboxylic acid, alcohol, ether, aldehyde, ketone, ester, carbonate or amine function. , nitrile, imide, amide, urea or oxime. For example, the organic compound containing oxygen and nitrogen can be one or more selected from the group consisting of 1,2-cyclohexanediaminetetraacetic acid, monoethanolamine (MEA), 1- methyl-2-pyrrolidinone, dimethylformamide, ethylenediaminetetraacetic acid (EDTA), alanine, glycine, nitrilotriacetic acid (NTA), N- (2-hydroxyethyl) ethylenediamine-N, N ', N '-triacetic (H EDTA), diethylenetriaminepentaacetic acid (DTPA), tetramethylurea, glutamic acid, dimethylglyoxime, bicine, tricine, 2-methoxyethyl cyanoacetate, 1-ethyl-2-pyrrolidinone , 1-vinyl-2- pyrrolidinone, 1, 3-dimethyl-2-imidazolidinone, 1- (2-hydroxyethyl) -2-pyrrolidinone, 1- (2-hydroxyethyl) -2,5-pyrrolidinedione, 1-methyl-2-piperidinone, 1-acetyl-2-azepanone, 1-vinyl-2-azepanone and 4-aminobutanoic acid.

The organic sulfur-containing compound can be one or more chosen from compounds comprising one or more chemical functions chosen from a thiol, thioether, sulfone or sulfoxide function. By way of example, the organic compound containing sulfur can be one or more chosen from the group consisting of thioglycolic acid, 2,2'-thiodiethanol, 2-hydroxy-4-methylthiobutanoic acid, a sulfonated derivative of a benzothiophene or a sulfoxidized derivative of a benzothiophene, methyl 3- (methylthio) propanoate and ethyl 3- (methylthio) propanoate.

Preferably, the organic compound contains oxygen, preferably it is chosen from g-valerolactone, 2-acetylbutyrolactone, triethylene glycol, diethylene glycol, ethylene glycol, ethylenediaminetetra-acetic acid (EDTA), 'maleic acid, malonic acid, citric acid, gluconic acid, dimethyl succinate, glucose, fructose, sucrose, sorbitol, xylitol, g-ketovaleric acid, dimethylformamide, 1-methyl-2-pyrrolidinone, propylene carbonate, 2-methoxyethyl 3-oxobutanoate, bicine, tricine, 2-furaldehyde (also known as furfuraldehyde), 5-hydroxymethylfurfural (also known as name 5- (hydroxymethyl) -2-furaldehyde or 5- HMF), 2-acetylfuran, 5-methyl-2-furaldehyde, ascorbic acid, butyl lactate, ethyl 3-hydroxybutanoate, 3 -ethylethoxypropanoate, 2-ethoxyethyl acetate, 2-butoxyethyl acetate, 2-hydroxyethyl acrylate, 1-vinyl-2-pyrrolidinone , 1, 3-dimethyl-2-imidazolidinone, 1- (2-hydroxyethyl) -2-pyrrolidinone, 1- (2-hydroxyethyl) -2,5-pyrrolidinedione, 5-methyl-2 (3H) - furanone, 1-methyl-2-piperidinone and 4-aminobutanoic acid.

In this case, the molar ratio of the organic compound added per metal from group VI B 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 very preferably between 0.1 and 1.5 mol / mol. When several organic compounds are present, the different molar ratios apply for each of the organic compounds present.

The impregnation step g) using an impregnation solution and in which said catalyst is brought into contact with an impregnation solution comprising a metal from group VIB and / or a metal from group VIII and / or phosphorus and / or an organic compound comprising oxygen and / or nitrogen and / or sulfur can be produced either by excess impregnation, or by dry impregnation, or by any other known means of Man skilled in the art.

Impregnation at equilibrium (or in excess), consists in immersing the support or the catalyst in a volume of solution (often considerably) greater than the pore volume of the support or of the catalyst while maintaining the system under agitation to improve the exchanges between the solution and the support or catalyst. An equilibrium is finally reached after diffusion of the different species into the pores of the support or catalyst. Control of the quantity of elements deposited is ensured by the preliminary measurement of an adsorption isotherm which links the concentration of elements to be deposited contained in the solution to the quantity of elements deposited on the solid in equilibrium with this solution.

Dry impregnation consists in introducing a volume of impregnation solution equal to the pore volume of the support or of the catalyst. Dry impregnation allows all of the metals and additives contained in the impregnation solution to be deposited on a given support or catalyst.

Any impregnation solution described above can comprise any polar protic solvent known to those skilled in the art. Preferably, a polar protic solvent is used, for example chosen from the group formed by methanol, ethanol and water. Preferably, the impregnation solution comprises a water-ethanol or water-methanol mixture as solvents in order to facilitate the impregnation of the compound containing a metal from group VIB (and optionally the compound containing a metal from group VIII and / or phosphorus and / or organic compound) on the catalyst. Preferably, the solvent used in the impregnation solution consists of water or of a water-ethanol or water-methanol mixture. In one possible embodiment, the solvent may be absent in the impregnation solution. In this case, phosphoric acid also acts as a solvent.

The impregnation step g) using an impregnation solution can be advantageously carried out by one or more impregnation in excess of solution or preferably by one or more dry impregnation and very preferably by only one dry impregnation of said catalyst, using the impregnation solution.

The impregnation step using an impregnation solution involves several implementation methods. They are distinguished in particular by the time of introduction of the organic compound when it is present and which can be carried out either at the same time as the impregnation of the metal of group VIB (co-impregnation), or after (post-impregnation). , or before (pre-impregnation). In addition, the modes of implementation can be combined. Preferably, a co-impregnation is carried out.

Advantageously, after each impregnation step, the impregnated support is allowed to mature. Curing allows the impregnation solution to disperse homogeneously within the substrate.

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

When performing several impregnation steps, each impregnation step is followed by an intermediate drying step and optionally by a calcination step as described below.

After the impregnation step g), a drying step h) is carried out. The drying step h) is carried out at a temperature below 200 ° C, advantageously between 100 ° C and below 200 ° C, preferably between 50 ° C and 180 ° C, more preferably between 70 ° C and 150 ° C, very preferably between 75 ° C and 130 ° C. The drying step is preferably carried out under an inert atmosphere or under an atmosphere containing oxygen.

When an organic compound is present, the catalyst is preferably dried without a subsequent calcination step. In this case, the drying is preferably carried out so as to preferably retain at least 30% by weight of the organic compound introduced, preferably this amount is greater than 50% by weight and even more preferably greater than 70% by weight, calculated. based on the carbon remaining on the catalyst. The remaining carbon is measured by elemental analysis according to ASTM D5373.

According to one variant, at the end of the drying step, a dried catalyst is then obtained, which will preferably be subjected to an optional activation step (sulfurization) for its subsequent use in a hydrotreatment process and / or hydrocracking.

According to another variant, the dried catalyst can be subjected to a calcination step i). The calcination step i) is carried out at a temperature between 200 ° C and 600 ° C, preferably between 250 ° C and 550 ° C, under an inert atmosphere (nitrogen for example) or under an atmosphere containing l oxygen (air for example). The duration of the calcination is generally between 0.5 hours and 16 hours, preferably between 1 hour and 5 hours.

Sulfurization step (optional step)

Before its use for the hydrotreatment and / or hydrocracking reaction, it is advantageous to convert the catalyst obtained according to the process according to the invention into a sulphide catalyst to form its active species. This activation or sulfurization step is carried out by methods well known to those skilled in the art, and advantageously in a sulfo-reducing atmosphere in the presence of hydrogen and hydrogen sulfide. This sulfurization can be carried out in situ or ex situ (inside or outside the reactor) of the reactor of the process according to the invention at temperatures between 200 and 600 ° C, and more preferably between 300 and 500 ° C.

The catalyst obtained at the end of step f), or optionally resulting from drying step h) or resulting from calcination step i), is therefore advantageously subjected to a sulfurization step.

Sulfurizing 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 the activation of the hydrocarbon feedstocks with a view to sulphurizing the catalyst. Said sulfur-containing compounds are advantageously chosen from alkyl disulphides such as, for example, dimethyl disulphide (DM DS), alkyl sulphides, such as for example dimethyl sulphide, thiols such as for example n -butylmercaptan (or 1-butanethiol) and polysulfide compounds of the tertiononylpolysulfide type. The catalyst can also be sulphurized by the sulfur contained in the feed to be desulphurized. Preferably, the catalyst is sulfurized in situ in the presence of a sulfurizing agent and a hydrocarbon feed. Very preferably, the catalyst is sulfurized in situ in the presence of a hydrocarbon feed supplemented with dimethyl disulfide.

Catalyst

After step f), the hydrotreatment and / or hydrocracking catalyst is obtained which comprises at least one metal from group VI B and a support comprising alumina. It may further comprise at least one metal from group VIII and / or phosphorus, and / or an organic compound comprising oxygen and / or nitrogen and / or sulfur.

The total content of metal from group VIB (introduced by the hydrated metal acid and optionally supplemented by impregnation using an impregnation solution comprising a metal from group VIB in post-impregnation) present in the catalyst is between 5 and 55% by weight, preferably between 10 and 50% by weight, and more preferably between 25 and 45% by weight expressed as group VI B metal oxide relative to the total weight of the catalyst.

The total content of metal from group VIII, when it is present, (introduced by the metal salt or by an impregnation using an impregnation solution comprising a metal from group VIII in post-impregnation) present in the catalyst is between 1 and 23% by weight, preferably between 2 and 18% by weight, and more preferably between 5 and 15% by weight expressed as group VIII metal oxide relative to the total weight of the catalyst.

The group VIII metal to group VI B metal molar ratio of the catalyst is generally between 0.1 and 0.8, preferably between 0.15 and 0.6.

Optionally, the catalyst can also have a total phosphorus content (introduced by phosphoric acid in step b) or by an impregnation using an impregnation solution comprising phosphoric acid in post- impregnation) present in the catalyst generally between 0.1 and 20% by weight of P2O5 relative to the total weight of catalyst, preferably between 0.2 and 15% by weight of P2O5, very preferably between 0.3 and 11% by weight of P2O5. For example, the phosphorus present in the catalyst is combined with the metal of group VI B and optionally also with the metal of group VIII in the form of heteropolyanions.

Furthermore, the phosphorus / (metal of group VIB) molar ratio is generally between 0.08 and 1, preferably between 0.1 and 0.9, and very preferably between 0.15 and 0.8 .

The contents of group VIB metal, group VIII metal and phosphorus in the catalyst are expressed as oxides after correction of the loss on ignition of the catalyst sample at 550 ° C for two hours in a muffle furnace. Loss on ignition is due to loss of moisture. It is determined according to ASTM D7348.

The total content of organic compound (s) containing oxygen and / or nitrogen and / or sulfur present in the catalyst after drying is generally between 1 and 30% by weight, preferably between 1, 5 and 25% by weight, and more preferably between 2 and 20% by weight relative to the total weight of the catalyst. The support comprises alumina. Preferably, it contains more than 50% by weight of alumina relative to the total weight of the support and, in general, it contains only alumina. Preferably, the alumina is gamma alumina. According to a particularly preferred variant, the support consists of gamma alumina.

In another preferred case, the support is a silica-alumina containing at least 50% by weight of alumina relative to the total weight of the 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%. The silica can be introduced in the form of precursors during step a) of mixing (kneading). According to another particularly preferred variant, the support consists of silica-alumina.

The support comprising alumina can also advantageously additionally contain from 0.1 to 80% by weight, preferably from 0.1 to 49% by weight of zeolite relative to the total weight of the support. In this case, all the sources of zeolite and all the associated preparation methods known to those skilled in the art can be incorporated. Preferably, the zeolite is chosen from the group FAU, BEA, ISV, IWR, IWW, MEI, UWY and preferably, the zeolite is chosen from the group FAU and BEA, such as zeolite Y and / or beta, and particularly preferably such as USY and / or beta zeolite.

The pore volume of the catalyst is generally between 0.1 cm ³ / g and 1.5 cm ³ / g, preferably between 0.15 cm ³ / g and 1.1 cm ³ / g. The total pore volume is measured by mercury porosimetry according to standard ASTM D4284 with a wetting angle of 140 °, as described in Rouquerol F.; Rouquerol J.; Singh K. "Adsorption by Powders & Porous Solids: Principle, methodology and applications", Academie Press, 1999, for example using a model Autopore III ™ apparatus of the brand Micromeritics ™.

The catalyst is characterized by a specific surface area of between 5 and 400 m ² / g, preferably between 10 and 350 m ² / g, preferably between 40 and 350 m ² / g, very preferably between 50 and 300 m ² / g. The specific surface area is determined in the present invention by the BET method according to the ASTM D3663 standard, a method described in the same work cited above. The catalyst is advantageously in the form of beads, extrudates, pellets or irregular and non-spherical agglomerates, the specific shape of which may result from a crushing step. Preferably, it is in the form of extrudates, particularly preferably in the form of trilobed or quadrilobed extrudates.

Hydrotreatment and / or hydrocracking process

Finally, another object of the invention is the use of the catalyst prepared by the preparation process according to the invention in hydrotreatment and / or hydrocracking processes of hydrocarbon cuts.

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

The hydrotreatment and / or hydrocracking process of hydrocarbon cuts is carried out in the presence of the catalyst prepared by the preparation process according to the invention. It can also be carried out in the presence of a mixture of the catalyst prepared by the preparation process according to the invention and of a catalyst prepared by conventional impregnation, using an impregnation solution, whether this be a fresh, regenerated or rejuvenated catalyst.

When the catalyst prepared by impregnation using an impregnation solution is present, it comprises at least one metal from group VIII, at least one metal from group VIB and an oxide support, and optionally phosphorus and / or an organic compound as described above.

The active phase and the support of the catalyst prepared by impregnation using an impregnation solution may or may not be identical to the active phase and to the support of the catalyst prepared by the preparation process according to the invention.

When the hydrotreatment and / or hydrocracking process of hydrocarbon cuts is carried out in the presence of a catalyst prepared by the preparation process according to the invention and of a catalyst prepared by conventional impregnation, it can be carried out in a reactor. of the fixed bed type containing several catalytic beds.

In this case, and according to a first variant, a catalytic bed containing the catalyst prepared by the preparation process according to the invention can precede a catalytic bed containing the catalyst prepared by conventional impregnation in the direction of flow of the feed.

In this case, and according to a second variant, a catalytic bed containing the catalyst prepared by conventional impregnation can precede a catalytic bed containing the catalyst prepared by the preparation process according to the invention in the direction of the flow of the feed.

In this case, and according to a third variant, a catalytic bed may contain a mixture of a catalyst prepared by the preparation process according to the invention and of a catalyst by conventional impregnation.

In these cases, the operating conditions are those described below. They are generally identical in the different catalytic beds except for the temperature which generally increases in a catalytic bed following the exothermic nature of the hydrodesulfurization reactions.

When the hydrotreatment and / or hydrocracking process of hydrocarbon cuts is carried out in the presence of a catalyst prepared by the preparation process according to the invention and of a catalyst prepared by conventional impregnation in several reactors in series of the bed type fixed or of the ebullating bed type, a reactor may comprise a catalyst prepared by the preparation process according to the invention while another reactor may comprise a catalyst prepared by conventional impregnation, or a mixture of a catalyst prepared by the process of preparation according to the invention and of a catalyst prepared by conventional impregnation, and this in any order. A device for removing the H2S from the effluent from the first hydrodesulfurization reactor can be provided before treating said effluent in the second hydrodesulfurization reactor. In these cases, the operating conditions are those described above and may or may not be identical in the different reactors.

The catalyst prepared according to the preparation process according to the invention and having preferably previously undergone a sulfurization step is advantageously used for the hydrotreatment and / or hydrocracking reactions of hydrocarbon feeds such as petroleum cuts, cuts resulting from coal or hydrocarbons produced from natural gas, optionally in mixtures or even from a hydrocarbon cut obtained from biomass and more particularly for the reactions of hydrogenation, hydrodenitrogenation, hydrodearomatization, hydrodesulfurization, hydrodeoxygenation, hydrodemetallation or d hydroconversion of hydrocarbon feeds.

In these uses, the catalyst which has preferably previously undergone a sulfurization step has an activity at least as good as the catalysts of the prior art. This catalyst can also advantageously be used during the pretreatment of catalytic cracking or hydrocracking feeds, or the hydrodesulfurization of residues or the extensive hydrodesulfurization of gas oils (ULSD Ultra Low Sulfur Diesel according to English terminology).

The feeds used in the hydrotreatment process are, for example, gasolines, gas oils, vacuum gas oils, atmospheric residues, vacuum residues, atmospheric distillates, vacuum distillates, heavy fuels, oils, waxes and paraffins, used oils, deasphalted residues or crude, feeds from thermal or catalytic conversion processes, lignocellulosic feeds or more generally feeds resulting from biomass such as vegetable oils, taken alone or as a mixture. The feeds that are processed, and in particular those mentioned above, generally contain heteroatoms such as sulfur, oxygen and nitrogen and, for heavy loads, they most often also contain metals.

The operating conditions used in the processes implementing the hydrotreatment reactions of hydrocarbon feeds 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 volume speed is advantageously between 0.1 and 20 fr ¹ and preferably between 0.2 and 5 fr ¹ , and the hydrogen / feed ratio expressed as a volume of hydrogen, measured under normal temperature and pressure conditions, per volume of liquid feed is advantageously between 50 l / l to 5000 l / l and preferably 80 to 2000 l / l. According to a first mode of use, said hydrotreatment process is a hydrotreatment process, and in particular hydrodesulfurization (H DS) process of a gas oil cut produced in the presence of at least one catalyst prepared according to the invention. Said hydrotreatment process aims to eliminate the sulfur compounds present in said gas oil cut so as to achieve the environmental standards in force, namely an authorized sulfur content of up to 10 ppm. It also makes it possible to reduce the aromatics and nitrogen contents of the diesel cut to be hydrotreated.

Said diesel cut to be hydrotreated contains from 0.02 to 5.0% by weight of sulfur. It is advantageously obtained from direct distillation (or straight run gas oil according to Anglo-Saxon terminology), from a coking unit (coking according to Anglo-Saxon terminology), from a visbreaking unit (visbreaking according to Anglo-Saxon terminology). Saxon), a steam cracking unit (steam cracking according to the English terminology), a hydrotreatment and / or hydrocracking unit for heavier feeds and / or a catalytic cracking unit (Fluid Catalytic Cracking according to Anglo-Saxon terminology). Said diesel cut preferably has at least 90% of the compounds whose boiling point is between 250 ° C and 400 ° C at atmospheric pressure.

The hydrotreatment process for said gas oil 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 volume ratio of hydrogen per volume of hydrocarbon feed, expressed as a volume of hydrogen, measured under normal temperature and pressure conditions, per volume of liquid feed, between 100 and 600 liters per liter and more preferably between 200 and 400 liters per liter and an hourly volume speed (WH) of between 1 and 10 h ¹ , preferably between 2 and 8 lr ¹ . The WH corresponds to the inverse of the contact time expressed in hours and is defined by the ratio of the volume flow rate of liquid hydrocarbon feedstock to the volume of catalyst loaded into the reaction unit implementing the hydrotreatment process according to the invention . The reaction unit implementing the hydrotreatment process for said gas oil cut is preferably carried out in a fixed bed, in a moving bed or in an ebullating bed, preferably in a fixed bed. According to a second mode of use, said hydrotreatment and / or hydrocracking process is a hydrotreatment process (in particular hydrodesulfurization, hydrodenitrogenation, hydrogenation of aromatics) and / or hydrocracking of a distillate cut under vacuum produced in the presence of at least one catalyst prepared according to the preparation process according to the invention. Said hydrotreatment and / or hydrocracking process, otherwise known as a hydrocracking or hydrocracking pretreatment process, is aimed, depending on the case, at removing the sulfur, nitrogen or aromatic compounds present in said distillate cut so as to carry out a pretreatment before conversion. in catalytic cracking or hydroconversion processes, or in hydrocracking the distillate cut which would possibly have been pretreated before if necessary.

A wide variety of feeds can be treated by the hydrotreating and / or hydrocracking processes of vacuum distillates described above. Generally they contain at least 20% by volume and often at least 80% by volume of compounds boiling above 340 ° C at atmospheric pressure. The feed may for example be vacuum distillates as well as feeds originating from units for extracting aromatics from lubricating oil bases or resulting from solvent dewaxing of lubricating oil bases, and / or deasphalted oils. , or else the feed can be a deasphalted oil or paraffins resulting from the Fischer-Tropsch process or even any mixture of the feeds mentioned above. In general, the charges have a boiling point T5 greater than 340 ° C at atmospheric pressure, and better still greater than 370 ° C at atmospheric pressure, that is to say that 95% of the compounds present in the charge have a point boiling above 340 ° C, and better still above 370 ° C. The nitrogen content of the feeds 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 feeds treated in the processes according to the invention is usually between 0.01 and 5.0% by weight. The filler can optionally contain metals (eg nickel and vanadium). The asphaltene content is generally less than 3000 ppm by weight.

The catalyst prepared according to the preparation process according to the invention is generally brought into contact, in the presence of hydrogen, with the charges 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 greater than 1 MPa, often between 2 and 25 MPa, preferably between 3 and 20 MPa, the volume speed being between 0.1 and 20.0 r ¹ and preferably 0.1 -6.0 lr ¹ , preferably 0, 2-3.0 fr ¹ , and the amount of hydrogen introduced is such that the volume ratio liter of hydrogen / liter of hydrocarbon, expressed as a volume of hydrogen, measured under normal temperature and pressure conditions, per volume of liquid feed, i.e. between 80 and 5,000 l / l and most often between 100 and 2,000 l / l. These operating conditions used in the processes according to the invention generally make it possible to achieve per-pass conversions, into products having boiling points lower than 340 ° C at atmospheric pressure, and better still lower than 370 ° C at atmospheric pressure, greater than at 15% and even more preferably between 20 and 95%.

The processes for hydrotreating and / or hydrocracking vacuum distillates using the catalysts prepared according to the preparation process according to the invention cover the pressure and conversion fields ranging from mild hydrocracking to high pressure hydrocracking. . The term “mild hydrocracking” means hydrocracking leading to moderate conversions, generally less than 40%, and operating at low pressure, generally between 2 MPa and 6 MPa.

The catalyst prepared according to the preparation process 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-step hydrocracking scheme, with or without liquid recycling. of the unconverted fraction, or else in a so-called two-step hydrocracking scheme, optionally in combination with a hydrorefining catalyst located upstream of the catalyst prepared according to the preparation process according to the invention.

According to a third mode of use, said hydrotreatment and / or hydrocracking process is advantageously implemented as a pretreatment in a fluidized bed catalytic cracking process (or FCC process for Fluid Catalytic Cracking according to English terminology) . The operating conditions of the pretreatment in terms of temperature range, pressure, hydrogen recycling rate, hourly volume speed are generally identical to those described above for the hydrotreatment and / or hydrocracking processes of vacuum distillates. The FCC process can be carried out in a standard known to those skilled in the art under the appropriate cracking conditions in order to produce hydrocarbon products of lower molecular weight. For example, a brief description of catalytic cracking can be found in ULLMANS ENCYCLOPEDIA OF INDUSTRIAL CHEMISTRY VOLUME A 18, 1991, pages 61 to 64.

According to a fourth mode of use, said hydrotreatment and / or hydrocracking process according to the invention is a hydrotreatment process (in particular hydrodesulfurization) of a gasoline cut in the presence of at least one catalyst prepared according to the invention. the preparation process according to the invention.

Unlike other hydrotreatment processes, the hydrotreatment (in particular hydrodesulfurization) of gasolines must make it possible to respond to a double antagonistic constraint: ensure deep hydrodesulfurization of the gasolines and limit the hydrogenation of unsaturated compounds present in order to limit loss of octane number.

The feed is generally a hydrocarbon cut having a distillation range of between 30 and 260 ° C. Preferably, this cut of hydrocarbons is a cut of the gasoline type. Very preferably, the gasoline cut is an olefinic gasoline cut obtained, for example, from a catalytic cracking unit (Fluid Catalytic Cracking according to English terminology).

The hydrotreatment process consists in bringing the hydrocarbon cut into contact with the catalyst prepared according to the preparation process according to the invention 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 an Hourly Volume Velocity (WH), defined as being the load volume flow based on the volume of catalyst, between 1 and 10 h ¹ , preferably between 2 and 6 fr ¹ and at a hydrogen / gasoline feed volume ratio of between 100 and 600 N l / l, preferably between 200 and 400 N l / l.

The gasoline hydrotreatment process can be carried out in one or more reactors in series of the fixed bed type or of the ebullated bed type. If the process is implemented by means of at least two reactors in series, it is possible to provide a device for eliminating H2S of the effluent from the first hydrodesulfurization reactor before treating said effluent in the second hydrodesulfurization reactor.

Examples

Example 1 Preparation of the co-mixed C1 reference catalyst 25.7 g of boehmite powder (loss on ignition of this powder: 32%) are introduced into the tank of a Z-arm mixer. The arms are rotated at a speed speed of 15 revolutions per minute, is started while 26.1 g of a solution of phosphomolybdic acid (concentration of the solution: 122 g of Mo / kg) and 170 mg of nitric acid diluted in 2.1 mL of water are added over two minutes. The speed of rotation is then fixed at 25 revolutions per minute for 30 minutes.

The paste obtained is collected and extruded through a cylindrical die with a diameter of 2 mm. The rods obtained are dried in an oven at 80 ° C. for 4 h then calcined in a muffle furnace at 540 ° C. for 4 h. Catalyst C1 is thus obtained which contains 22% by weight of

M 0O3. Example 2: Preparation of the C2 co-mixed catalyst in accordance with the invention

27.81 g of boehmite powder (loss on ignition of this powder: 32%) are introduced into the tank of a Z-arm mixer. The rotation of the arms, at a speed of 15 revolutions per minute, is started. while 189 mg of nitric acid diluted in 16.9 mL of water are added over two minutes. The speed of rotation is then set at 25 revolutions per minute, which allows the passage to paste.

After 10 minutes of mixing, 7.19 g of hydrated phosphomolybdic acid H ₃ PM0 ₁ 2O ₄₀ .28H2O (PMA), the melting point of which is 85 ° C., are added to the tank. The heating of the mixer tank is started with the set temperature of 85 ° C and the mixing is continued for a further 30 minutes. The paste obtained is collected and extruded through a cylindrical die with a diameter of 2 mm. The rods obtained are dried in an oven at 80 ° C. for 4 h then calcined in a muffle furnace at 540 ° C. for 4 h. Catalyst C2 is thus obtained which contains 22% by weight of M0O ₃ . Example 3: Preparation of catalyst C3 in accordance with the invention

26.5 g of boehmite powder (loss on ignition of this powder: 32%) are introduced into the tank of a Z-arm mixer. The rotation of the arms, at a speed of 15 revolutions per minute, is started. while 180 mg of nitric acid diluted in 16.1 mL of water are added over two minutes. The speed of rotation is then set at 25 revolutions per minute, which allows the passage to paste.

After 10 minutes of mixing, 8.53 g of PMA are added to the tank. The heating of the mixer tank is started with the set temperature of 85 ° C and the mixing is continued for a further 30 minutes. The paste obtained is collected and extruded through a cylindrical die with a diameter of 2 mm. The rods obtained are dried in an oven at 80 ° C. for 4 h then calcined in a muffle furnace at 540 ° C. for 4 h. The catalyst C3 is thus obtained which contains 26% by weight of M0O3.

Example 4 Preparation of catalyst C4 according to the invention 18.96 g of boehmite powder (loss on ignition of this powder: 32%) are introduced into the tank of a Z-arm mixer. The rotation of the arms, at a speed of 15 revolutions per minute, is started while 129 mg of nitric acid diluted in 12.4 mL of water are added over two minutes. The speed of rotation is then set at 25 revolutions per minute, which allows the passage to paste. After 10 minutes of mixing, 16.04 g of PMA are added to the tank. The heating of the mixer tank is started with the set temperature of 85 ° C and the mixing is continued for a further 30 minutes.

The paste obtained is collected and extruded through a cylindrical die with a diameter of 2 mm. The rods obtained are dried in an oven at 80 ° C. for 4 h then calcined in a muffle furnace at 540 ° C. for 4 h. The catalyst C4 is thus obtained which contains 48% by weight of MOO3. Example 5 Preparation of catalyst C5 in accordance with the invention

24.30 g of boehmite powder (loss on ignition of this powder: 32%) are introduced into the tank of a mixer arm in Z. The rotation of the arms, at a speed of 15 revolutions per minute, is started. while 165 mg of nitric acid diluted in 15.5 mL of water are added over two minutes. The speed of rotation is then set at 25 revolutions per minute, which allows the passage to paste.

After 10 minutes of mixing, 6.68 g of PMA and 4.02 g of cobalt nitrate hexahydrate are added to the tank. The heating of the mixer tank is started with the set temperature of 85 ° C and the mixing is continued for a further 30 minutes.

The paste obtained is collected and extruded through a cylindrical die with a diameter of 2 mm. The rods obtained are dried in an oven at 80 ° C. for 4 h then calcined in a muffle furnace at 540 ° C. for 4 h. Catalyst C5 is thus obtained which contains 22 wt% M0O3 and 4.6 wt% CoO.

Example 6: Evaluation of catalysts C1 to C6 in the hydrogenation of toluene

The catalysts were evaluated for the hydrogenation of toluene under sulfo-reducing conditions. The feed consists of dimethyldisulfide (5.9% wt) and toluene (20% wt) as a mixture in cyclohexane. The catalysts are pre-sulphurized in situ with the test feed at an hourly volume velocity (WH) of 4 h ¹ , a hydrogen to feed ratio of 450 L / L and a pressure of 6 MPa (60 bar). The temperature is increased from ambient conditions to 350 ° C with a ramp of 2 ° C min- ¹ . The catalytic test is then carried out with the following conditions: a temperature of 350 ° C, a pressure of 6 MPa (60 bar), an hourly volume speed (WH) of 2 h ¹ , and a hydrogen to feed ratio of 450 L / L. The reaction products are analyzed online by gas chromatography. The hydrogenation activity of toluene (A Hydro) is expressed by considering an order of 1 according to the following equation and in relation to the activity of catalyst C1, 22% by weight M0O3 prepared by conventional co-mixing. kHYD = WH x Ln (1 / (l-Xroiuene)) with X _ioiuene , conversion of toluene by hydrogenation

The activity results are given in the following table. These results show that a catalyst prepared by melt co-mixing with the same 22 wt% molybdenum oxide content is more active than the standard catalyst prepared by conventional co-mixing with an activity of 117.

Increasing the amount of molybdenum oxide by melt co-mixing to 26 wt% gives an activity of 143.

Increasing the amount of molybdenum oxide by moly co-mixing to 48 wt%, which would not be possible by conventional co-mixing, gives an activity of 235.

The catalyst prepared by melt co-mixing with cobalt and molybdenum gives an activity of 538.

Claims

1. Process for preparing a hydrotreatment and / or hydrocracking catalyst comprising at least one metal from group VIB and a support comprising alumina, the content of metal from group VIB being between 5 and 55% by weight expressed as metal oxide from group VIB relative to the total weight of the catalyst, said process comprising the following steps: a) an alumina precursor is mixed with an aqueous solution, optionally containing an inorganic acid, in order to obtain a paste, b) said paste obtained in step a) is brought into contact with at least one hydrated metal acid comprising at least one metal from group VIB whose melting point of said hydrated metal acid is between 20 and 100 ° C, to form a paste containing the hydrated metal acid, the mass ratio between said metal acid and said alumina precursor being between 0.05 and 2.2, c) the paste containing the hydrated metal acid obtained at the end is heated with stirring of th step b) at a temperature between the melting point of said metallic acid and 100 ° C, c ') optionally contacting said paste obtained in step c) with an aqueous solution containing a base, d) placing in contact forms the paste obtained in step c) or in step c '), e) the shaped paste is dried at a temperature below 200 ° C to obtain a dried catalyst, f) the dried catalyst is calcined at a temperature between 200 and 1000 ° C.

2. Method according to the preceding claim, wherein in step b) the hydrated metal acid is chosen from hydrated phosphomolybdic acid, hydrated silicomolybdic acid, hydrated molybdosilicic acid, hydrated phosphotungstic acid and hydrated silicotungstic acid.

3. Method according to one of the preceding claims, wherein in step a) the alumina precursor is boehmite.

4. Method according to one of the preceding claims, wherein in step a) a silicon precursor is further added to the mixture.

5. Method according to one of the preceding claims, wherein in step a) the inorganic acid is selected from nitric acid, hydrochloric acid, sulfuric acid and phosphoric acid.

6. Method according to one of the preceding claims, wherein in step c ') the base is chosen from ammonia, a mono-alkylamine, a dialkylamine, a tri-alkylamine, a tetra-alkylammonium hydroxide. .

7. Method according to one of the preceding claims, wherein step b) further comprises contacting with at least one metal salt comprising at least one metal from group VIII, the melting point of said metal salt is between 20 and 100 ° C, the molar ratio (metal of group VI I l) / (metal of group VI B) being between 0.1 and 0.8.

8. A method according to the preceding claim, wherein said metal salt is a hydrated nitrate salt.

9. Method according to the preceding claim, wherein said metal salt is chosen from nickel nitrate hexahydrate, and cobalt nitrate hexahydrate, taken alone or as a mixture.

10. Method according to one of the preceding claims, wherein step b) further comprises contacting with phosphoric acid, the molar ratio phosphorus / (metal of group VIB) being between 0.08 and 1.

11. Method according to one of the preceding claims, wherein step b) further comprises contacting with an organic compound comprising oxygen and / or nitrogen and / or sulfur whose temperature. melting point of said organic compound is between 20 and 100 ° C, the organic compound / metal of group VIB molar ratio being between 0.01 and 5.

12. The method of the preceding claim, wherein the organic compound is selected from maleic acid, sorbitol, xylitol, g-ketovaleric acid, 5-hydroxymethylfurfural and 1, 3-dimethyl-2-imidazolidinone.

13. Method according to one of the preceding claims, wherein after step f) an impregnation step g) is carried out using an impregnation solution and in which said catalyst is brought into contact with an impregnation solution. impregnation solution comprising a metal from group VI B and / or a metal from group VIII and / or phosphorus and / or an organic compound comprising oxygen and / or nitrogen and / or sulfur, followed by 'a drying step h) at a temperature below 200 ° C and optionally a calcination step i) at a temperature between 200 ° C and 600 ° C under an inert atmosphere or under an oxygen-containing atmosphere.

14. Method according to the preceding claim, wherein the organic compound is chosen from g-valerolactone, 2-acetylbutyrolactone, triethylene glycol, diethylene glycol, ethylene glycol, ethylenediaminetetra-acetic acid, maleic acid, l ' malonic acid, citric acid, gluconic acid, dimethyl succinate, glucose, fructose, sucrose, sorbitol, xylitol, g-ketovaleric acid, dimethylformamide, 1-methyl-2- pyrrolidinone, propylene carbonate, 2-methoxyethyl 3-oxobutanoate, bicine, tricine, 2-furaldehyde, 5-hydroxymethylfurfural, 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, 1-vinyl -2-pyrrolidinone, 1, 3-dimethyl-2-imidazolidinone, 1- (2-hydroxyethyl) -2-pyrrolidinone, 1- (2-hydroxyethyl) -2,5-pyrroli dinedione, 5-methyl-2 (3H) -furanone, 1-methyl-2-piperidinone, and 4-aminobutanoic acid.

15. Method according to one of the preceding claims, wherein the catalyst is subjected to a sulfurization step after step f) or after optional steps h) or i).

16. Catalyst obtained according to the preparation process according to claims 1 to 15.

17. Use of the catalyst prepared according to one of claims 1 to 15 in a hydrotreatment and / or hydrocracking process of hydrocarbon cuts.