WO2021121982A1

WO2021121982A1 - Process for the preparation of a hydrotreating and/or hydrocracking catalyst by impregnation in a melted medium, catalyst obtained, and use thereof

Info

Publication number: WO2021121982A1
Application number: PCT/EP2020/084177
Authority: WO
Inventors: Elodie Devers; Audrey BONDUELLE-SKRZYPCZAK; Mathieu Digne; Anne BOFFO; Malika Boualleg
Original assignee: IFP Energies Nouvelles
Priority date: 2019-12-17
Filing date: 2020-12-01
Publication date: 2021-06-24
Also published as: FR3104465B1; FR3104465A1

Abstract

The invention relates to a process for the preparation, by impregnation in a melted medium, of a hydrotreatment and/or hydrocracking catalyst, said process comprising the following steps: a) bringing water in contact with said porous support so as to obtain a wet porous support; b) bringing said wet porous support in contact with at least one hydrated metal acid comprising at least one group VIB metal, wherein the melting temperature of said hydrated solid metal acid is between 20 and 100 °C, in order to form a solid mixture, the weight ratio between the metal acid and the porous support being between 0.1 and 2.5; c) heating while stirring the solid mixture obtained at the end of step b) to a temperature between the melting temperature of the metal acid and 100 °C. The invention also relates to the catalyst and its use in the field of hydrotreatment and/or hydrocracking.

Description

PROCESS FOR THE PREPARATION OF A HYDROTREATMENT AND / OR HYDROCRACKING CATALYST BY IMPREGNATION IN MELTED 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 impregnation 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, the purpose of a hydrotreatment catalyst for hydrocarbon cuts is 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 forms5 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. de5 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 this 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. However, 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 VIB 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.

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 impregnation in a molten medium.

Objects of the invention

The invention relates to a process for preparing a hydrotreatment and / or hydrocracking catalyst comprising a porous support based on alumina or silica or silica-alumina and at least one metal from group VIB, 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) water is brought into contact with said porous support of so as to obtain a wet porous support, b) said wet porous support is brought into contact with at least one hydrated metal acid comprising at least one metal from group VIB, the melting point of said hydrated metal acid of which is between 20 and 100 ° C. , to form a solid mixture, the mass ratio between said metallic acid and said porous support being between 0.1 and 2.5, c) the solid mixture obtained at the end of step b) is heated with stirring at a temperature between the melting point of said hydrated metal acid is 100 ° C. The Applicant has in fact observed that the use of hydrated metal acid comprising at least one metal from group VIB and having a melting point of between 20 and 100 ° C makes it possible to introduce a metal from group VIB into a porous support by impregnation in molten medium.

The hydrated metallic acid, which is in the form of powder, is mixed with the porous support (step b), then this solid mixture is heated in order to melt the metallic acid in the support, thus making it possible to obtain the catalyst ( step c). However, the acid has the peculiarity of only melting in the presence of sufficient partial pressure of water. In other words, it is necessary to keep the molecules of water of crystallization to ensure its fusion. In order to guarantee sufficient partial water pressure, the support is first moistened by impregnating with water (step a).

The preparation process according to the invention thus has the advantages of an impregnation in a molten medium, in particular the absence of any preparation of solution or the use of solvent and the absence of the need for drying or subsequent calcination even if such steps are possible.

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 not achievable by impregnation using a solution of impregnation.

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 impregnation using an impregnation solution. with however a simplified preparation and the possibility of loading more metal of 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, the quantity of water introduced into the support in step a) is between 10 and 70% of its water uptake volume. 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, to form a solid mixture, the molar ratio (metal of group VI I l) / (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 to form a solid mixture, the phosphorus / (group VI B 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 VI B 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.

Alternatively, after step c), a step d) of drying the catalyst obtained in step c) is carried out at a temperature below 200 ° C.

According to one variant, a step e) of calcining the catalyst obtained in step d) is carried out at a temperature greater than or equal to 200 ° C and less than or equal to 600 ° C under an inert atmosphere or under an atmosphere containing oxygen. .

According to one variant, before step a) or after step c), an impregnation step is carried out using an impregnation solution and in which said support or said catalyst is brought into contact with a solution. impregnation 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 at a temperature below 200 ° C and optionally a calcination step at a temperature greater than or equal to 200 ° C and less than or equal to 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.

According to one variant, the catalyst is subjected to a sulfurization step after step c) or the optional steps d) and e).

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 a porous support based on alumina or silica or silica-alumina and at least one metal from group VIB, 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) water is brought into contact with said porous support of so as to obtain a wet porous support, b) said wet porous support 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 solid mixture, the mass ratio between said metallic acid and said porous support being between 0.1 and 2.5, c) the solid mixture 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 a): Contacting the water with the oxide support

According to step a) of the preparation process according to the invention, water is brought into contact with said porous support so as to obtain a wet porous support.

This step of wetting the porous support is necessary in order to be able to melt the hydrated metal acid in step c). This is because the acid has the particularity of only melting in the presence of sufficient partial pressure of water. In other words, it is necessary to keep the water molecules of crystallization of the metallic acid hydrated to ensure its fusion.

Contacting step a) can be carried out by dry impregnation. The water can for example be poured drop by drop onto the support contained in a rotating bezel.

According to one variant, the quantity of water introduced into the porous support is between 10 and 70%, and preferably between 30 and 50% of its water uptake volume.

Advantageously, after the water has come into contact with the support, the wet porous support is allowed to mature. Maturation allows the water to disperse homogeneously within the porous support.

Any maturation step 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, preferably between thirty minutes and fifteen hours and particularly preferably between thirty minutes and six hours, is sufficient. The porous support is a porous support based on alumina or silica or silica-alumina.

The porous support advantageously has a total pore volume of between 0.1 and 1.5 cm ³ . g- ¹ , preferably between 0.4 and 1.1 cm ³ . g ¹ . 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 specific surface of the porous support is advantageously between 5 and 400 m ² . g- ¹ , preferably between 10 and 350 m ² .g- ¹ , more preferably between 40 and 350 m ² .g- ¹ . 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 porous support has a water uptake volume or VRE of between 0.2 and 1.6 cm ³ . g ¹ , preferably between 0.5 and 1, 2 cm ³ . g ¹ . The retention volume is determined as follows: poured over a known mass of support, placed in a bezel rotated with the aid of a motor, deionized water, drop by drop using of a graduated burette, while the support is mixed manually using a spatula. When the support begins to adhere to the wall of the bezel, the drip is stopped and the volume of water used is noted. The volume of water / mass of support ratio is then calculated, the water uptake volume (VRE) being expressed in cm ³ / g.

When the oxide support is based on alumina, it contains more than 50% by weight of alumina relative to the total weight of the support and, in general, it contains only alumina or silica-alumina such as as defined below.

Preferably, the oxide support comprises alumina, and more preferably extruded alumina. Preferably, the alumina is gamma alumina.

In another preferred case, the porous 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 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 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.

When the support of said catalyst is based on silica, it contains more than 50% by weight of silica relative to the total weight of the support and, in general, it contains only silica.

According to a particularly preferred variant, the oxide support consists of alumina, silica or silica-alumina. According to a particularly preferred variant, the oxide support consists of gamma alumina.

The oxide support can also advantageously additionally contain from 0.1 to 80% by weight, preferably from 0.1 to 50% 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 support is advantageously in the form of balls, extrudates, pellets or irregular and non-spherical agglomerates, the specific shape of which may result from a crushing step.

Step b): Bringing the metallic acid into contact with the wet support

According to step b) of the preparation process according to the invention, said wet porous support is brought into contact with at least one hydrated metal acid comprising at least one metal from group VI B, the melting point of said hydrated metal acid of which is within between 20 and 100 ° C, to form a solid mixture, the mass ratio between said hydrated metallic acid and said porous support being between 0.1 and 2.5. The hydrated metal acid must have a relatively low melting point, especially lower than its decomposition temperature. The melting point of the 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 (hUSiMo ^ Cho, XH2O, melting point T = 47-55 ° C), hydrated molybdosilicic acid (H ₆ Moi ₂ 0 _4i Si, XH2O, melting point T = 45-70 ° C), hydrated phosphotungstic acid (H3PW12O40, 28H2O, melting point T = 89 ° C ), hydrated silicotungstic acid (hUSiW ^ C o, XH2O, melting point T = 53 ° C).

The mass ratio between said hydrated metal acid and said porous support is between 0.1 and 2.5, preferably between 0.3 and 2.0.

In this step, the hydrated metallic acid is in solid form, that is to say that the bringing into contact between said porous support and said hydrated metallic acid is carried out 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 porous support and hydrated metal acid can be done by any method known to those skilled in the art. Preferably, the placing in contact of said porous support and of said hydrated metal acid is carried out with contact means chosen from among convective mixers, drum mixers or static mixers.

Step b) is preferably carried out for a period of between 5 minutes to 12 hours depending on the type of mixer used, preferably between 10 minutes and 4 hours, and even more preferably between 15 minutes and 3 hours. According to a first variant, step b) consists of bringing said wet porous support into contact with at least one hydrated metal acid comprising at least one metal from group VI B, the melting point of said hydrated solid metal acid of which is between 20 and 100 ° C, to form a solid mixture, the mass ratio between said metallic acid and said porous support being between 0.1 and 2.5.

Although the addition of other solid compounds to the catalyst obtained according to the preparation process of the invention after step c) is not necessary to obtain a catalytic activity close to those of catalysts according to the state of the art (prepared by impregnation using an impregnation 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, to form a solid mixture with the porous support and the hydrated metal acid, 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 (NC> 3) 2, 6H ₂ O, melting point T = 55.0 ° C), taken alone or as a mixture.

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. 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 on the surface of 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 of group VIB) in order to ultimately increase the catalytic activity, one can add to the porous support / hydrated metal acid mixture a phosphorus compound in solid form, in particular phosphoric acid. 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, to form a solid mixture with the porous support and the hydrated metal acid and optionally the metal salt comprising at least one group VIII metal.

The phosphorus / (metals 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 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, to form a solid mixture with the porous support and the hydrated metal acid, and optionally the metal salt comprising at least one metal from group VIII and phosphoric acid.

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.

Step c): Heating with stirring

According to step c) of the preparation process according to the invention, the solid mixture obtained at the end of step b) is heated with stirring to a temperature between the melting point of said hydrated metal 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.

Even more preferably, step c) is carried out by means of a drum mixer whose speed of rotation is between 4 and 70 revolutions / minute, preferably between 10 and 60 revolutions / minute.

After step c), the hydrotreatment and / or hydrocracking catalyst is obtained which comprises at least one porous support based on alumina or on silica or on silica-alumina and at least one metal from group VIB in the form of hydrated metallic acid.

Step d): Drying (optional)

After heating step c), the catalyst can be subjected to a drying step d) 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 d) is generally higher than the heating temperature of step c). Preferably, the drying temperature of step d) 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 bed passed through 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.

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

The drying step can in particular be carried out when an organic compound is present. 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.

Step e): Calcination (optional)

According to another variant, at the end of the drying step d), a calcination step e) 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 oxygen (air for example). The duration of this heat treatment is generally between 0.5 hours and 16 hours, preferably between 1 hour and 5 hours. 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 introduced. 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.

When an organic compound is present, whether it is introduced by impregnation in a molten medium or by impregnation using an impregnation solution, the catalyst is preferably not subjected to calcination. Impregnation step using an impregnation solution via post-impregnation (optional)

According to one variant, it may be advantageous in certain cases to add to the catalyst obtained according to stage c) of the preparation process according to the invention, or to the catalyst obtained after the optional drying stage d) or after stage optional e) calcining at least one of the additional metal precursors by impregnation using an impregnation solution (conventional 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 heating step c), or the optional drying step d) or the optional calcination step e), can be followed by an impregnation step using a 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.

In this case, the metal from group VIB, when it is introduced, is preferably chosen from molybdenum and tungsten. The group VIII metal 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 preferably the active phase consists of cobalt and molybdenum, of 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 c).

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 (H3PM012O40), and their salts, and optionally silicomolybdic acid (HUSiMo ^ C 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 (hUSiW ^ O ^) 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 of group VI I l) / (metal of group VI B) is generally between 0.1 and 0.8, preferably between 0.15 and 0.6.

Phosphorus can also be added to 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 VI B is between 0.1 and 2.5 mol / mol, preferably between 0.1 and 2.0 mol / mol, and even more preferred 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. 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.

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 glycoldimethylether, glycerol, acetophenone, 2,4-pentanedione, pentanone, acetic acid, maleic acid, malic acid, malonic acid, oxalic acid, gluconic acid, tartaric acid, citric acid, g-ketovaleric acid, a succinate of C1-C4 dialkyl, and more particularly dimethyl succinate, methyl acetoacetate, ethyl acetoacetate, 2-methoxyethyl 3-oxobutanoate, 2-methacryloyloxyethyl 3-oxobutanoate, dibenzofuran, a crown ether , orthophthalic acid, glucose, fructose, sucrose, sorbitol, xylitol, g-valerolac tone, 2-acetylbutyrolactone, propylene carbonate, 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, ethyl 3-hydroxybutanoate, ethyl 3-ethoxypropanoate, methyl 3-methoxypropanoate, 2-ethoxyethyl acetate, 2-butoxyethyl acetate, 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- 2-methyl-pyrrolidinone, dimethylformamide, ethylenediaminetetraacetic acid (EDTA), alanine, glycine, nitrilotriacetic acid (NTA), N- (2-hydroxyethyl) ethylenediamine-N, N ', N '- triacetic (HEDTA), diethylene-triaminepentaacetic 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 compound containing sulfur 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 benzothiophene or a sulfoxide 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 VIB in the catalyst is between 0.01 and 5 mol / mol, preferably between 0.05 and 3 mol / mol, preferably between 0 0.05 and 2 mol / mol and very preferably between 0.1 and 1.5 mol / mol.

When more than one organic compound is present, the different molar ratios apply for each of the organic compounds present.

The impregnation step 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 means known to those skilled in the art. job. 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 prior measurement of an adsorption isotherm which links the concentration of the 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 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 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 a single impregnation with dryness of said catalyst, using the impregnation solution.

The impregnation step using an impregnation solution comprises several modes of implementation. 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). , is 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 carrying out several impregnation steps, each impregnation step is preferably followed by an intermediate drying step 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 °. Optionally, a maturation period was observed between the impregnation step and the intermediate drying step. In addition, a calcination step can be carried out after the drying step, at a temperature between 200 ° C and 600 ° C, preferably between 250 ° C and 550 ° C, under an inert atmosphere ( nitrogen for example) or in an atmosphere containing oxygen (air for example).

Impregnation step using an impregnation solution via pre-impregnation (optional)

According to another variant, it may be advantageous in certain cases to add, before step a) of the process according to the invention, to the porous support based on alumina or on silica or on silica-alumina at least one of the precursors. metals and / or phosphorus and / or an additional organic compound by impregnation using an impregnation solution (conventional prepreg).

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, step a) of bringing water into contact with the oxide support can be preceded by an impregnation step using an impregnation solution and in which in contact with said catalyst with an 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 or sulfur.

The pre-impregnation step can be performed in the same way as the post-impregnation step described above. It generally comprises at least one impregnation step, followed by drying and possibly calcination as described for the post-impregnation step.

This pre-impregnation step is particularly advantageous when it is desired to introduce an organic compound having a melting point above 100 ° C.

Among the organic compounds comprising oxygen and / or nitrogen and / or sulfur and having a melting point higher than 100 ° C, one will preferably choose malonic acid, citric acid, acid gluconic, glucose, fructose, 2-methoxyethyl 3-oxobutanoate, 5-methyl-2-furaldehyde.

In this case, the molar ratio of the organic compound added per metal from group VI B present in the catalyst subsequently introduced via impregnation in a molten medium and optionally supplemented by a pre- or post-impregnation 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 an organic compound is present, the catalyst is preferably not subjected to calcination.

Step e) Sulfurization (optional step)

Before its use for the hydrotreatment and / or hydrocracking reaction, it is advantageous to transform the catalyst obtained according to the process according to the invention into a sulfurized catalyst in order to form its active species. This stage of activation or sulfurization is carried out by methods well known to those skilled in the art, and advantageously under 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 c), or optionally resulting from drying step d) or resulting from calcination step e), 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 c), the hydrotreatment and / or hydrocracking catalyst is obtained which comprises at least one porous support based on alumina or on silica or on silica-alumina and at least one metal from group VI B under form of hydrated metallic acid. 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.

Unlike the catalysts prepared by conventional impregnation, the catalyst prepared according to the preparation process according to the invention partially retains the heteropolyanions introduced by the hydrated metal acid. Heteropolyanions are visible by Raman spectroscopy.

The catalyst obtained thus has a characteristic Raman spectrum grouping together characteristic bands of the heteropolyanion (s) of Keggin PXYnC _t f and / or RUi ₂ 0 ₄ o ^{c type} - where Y is a metal from group VIB and X is a metal from group VIII (and X x).

According to Griboval, Blanchard, Payen, Fournier, Dubois in Catalysis Today 45 (1998) 277 fig. 3 e), the main bands of the PCoMon0 ₄ o ^x structure are on catalyst dried at 232, 366, 943, 974 cm ¹ and according to MT Pope "Heteropoly and Isopoly oxometalates", Springer Verlag, p 8, these bands are not characteristic of the nature of the X or Y atom, but of the structure of the heteropolyanion. The most intense band characteristic of this type of lacunar Keggin heteropolyanion is at 974 cnr ¹ .

According to Griboval, Blanchard, Gengembre, Payen, Fournier, Dubois, Bernard, Journal of Catalysis 188 (1999) 102, fig. 1 a), the main bands of PMoi ₂ 0 ₄ o ^x_ are in the mass state of G heteropolyanion, for example with cobalt in counterion at 251, 603, 902, 970, 990 cm ¹ . The most intense band characteristic of this Keggin heteropolyanion is located at 990 cm ¹ . MT Pope "Heteropoly and Isopoly oxometalates", Springer Verlag, p 8, also teaches us that these bands are not characteristic of the nature of the X or Y atom, but of the structure of G heteropolyanion of Keggin, complete, lacunar or substituted.

The exact position of the bands, their shapes and their relative intensities may vary to some extent depending on the recording conditions of the spectrum, while remaining characteristic of this molecule. Raman spectra of organic compounds are also well documented either in Raman spectrum databases (see for example, Spectral Database for Organic Compounds, http://riodb01.ibase.aist.go.jp/sdbs/cgi- bin /direct_frame_top.cgi) or by the suppliers of the product (see for example, www.sigmaaldrich.com).

The Raman spectra were obtained with a dispersive Raman type spectrometer equipped with an argon ionized laser (514 nm). The laser beam is focused on the sample using a microscope equipped with a x50 long working distance objective. The power of the laser sample level is of the order of 1 mW. The Raman signal emitted by the sample is collected by the same objective and is dispersed using an 1800 rpm network then collected by a CCD detector. The spectral resolution obtained is of the order of 0.5 cm ^{· 1} . The spectral zone recorded is between 300 and 1800 cm ¹ . The acquisition time was set at 120 s for each Raman spectrum recorded.

The total content of metal from group VI B (introduced by the hydrated metal acid and optionally supplemented by impregnation using an impregnation solution comprising a metal from group VI B in pre- or 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 pre- or 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 may also have a total phosphorus content (introduced by phosphoric acid by impregnation in a molten medium or by impregnation using an impregnation solution comprising phosphoric acid) present in the mixture. 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 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 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.

Hydrotreatment and / or hydrocracking process

Finally, another subject of the invention is the use of the catalyst prepared by the preparation process according to the invention in processes for the hydrotreatment and / or hydrocracking of hydrocarbon cuts. The process for 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 ebullating 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 circulation 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 as a result of 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. It is possible to provide a device for removing the hhS from the effluent issuing from the first hydrodesulfurization reactor 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, d 'hydrodeoxygenation, hydrodemetallation or 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 feedstocks, or the hydrodesulphurization of the residues or the extensive hydrodesulphurization of gas oils (U LSD 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 h ¹ and preferably between 0.2 and 5 h 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 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 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 h 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 processes or hydroconversion, 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 hydrotreatment 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 may 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 fr ¹ and preferably 0.1 -6.0 h ¹ , preferably 0, 2-3.0 fr ¹ , and the quantity of hydrogen introduced is such that the ratio volume liter of hydrogen / liter of hydrocarbon, expressed in 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 2000 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 below 340 ° C. at atmospheric pressure, and better still less than 370 ° C. at atmospheric pressure, greater than 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 conventional manner known to those skilled in the art under suitable 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 the unsaturated compounds present in order to limit the 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 removing the H2S from the effluent from the first hydrodesulfurization reactor before treating said effluent in the second hydrodesulfurization reactor.

The examples which follow demonstrate that 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 impregnation using a impregnation solution with, however, a simplified preparation and the possibility of loading more metal of group VI B. Examples

Example 1: Preparation of the reference catalyst C1

Catalyst C1 is prepared by dry impregnation of a gamma alumina (SBET 270 m ² / g, Vp 0.75 cm ³ / g), crushed so as to obtain grains of 300 to 500 μm (VRE 1.2 cm ³ / g), with a solution containing hydrated phosphomolybdic acid H ₃ PMoi ₂ C> ₄ o, 28H ₂ C> (PMA). The concentration of PMA in solution is adjusted so as to obtain 22% by weight of M0O3 on the final catalyst. After maturing for 3 hours, the catalyst is dried at 120 ° C. for 2 hours.

Example 2: Preparation of catalyst C2 in accordance with the invention

10 g of the same support crushed to 300-500 μm used for the preparation of catalyst C1 was pre-impregnated with water by adding 5 cm ³ of water, ie 42% of the VRE. The water is poured drop by drop onto the support contained in a rotating bezel. In order to let the support soak up properly, it is placed in a maturator for 1 h. The support prepreg with water is then transferred to the reactor and 4 g of PMA, the melting point of which is 85 ° C., are added. The reflux is set up and the reactor is heated to 85 ° C. with stirring for 3 h. The catalyst is then left to mature for 18 hours. Catalyst C2 is thus obtained which contains 22% by weight of M0O3.

Example 3: Preparation of catalyst C3 according to the invention

10 g of the same support crushed to 300-500 μm used for the preparation of catalyst C1 was pre-impregnated with water by adding 5 cm ³ of water, ie 42% of the VRE. The water is poured drop by drop onto the support contained in a rotating bezel. In order to let the support soak up properly, it is placed in a maturator for 1 h. The support pre-impregnated with water is then transferred to the reactor and 4.85 g of PMA are added. The reflux is set up and the reactor is heated to 85 ° C. with stirring for 3 h. The catalyst is then left to mature for 18 hours. The catalyst C3 is thus obtained which contains 26% by weight of M0O3. Example 4 Preparation of the catalyst C4 in accordance with the invention

10 g of the same support crushed to 300-500 μm used for the preparation of catalyst C1 was pre-impregnated with water by adding 5 cm ³ of water, ie 42% of the VRE. The water is poured drop by drop onto the support contained in a rotating bezel. In order to let the support soak up properly, it is placed in a ripener for 1 hour. The support prepreg with water is then transferred to the reactor and 13 g of PMA are added. The reflux is set up and the reactor is heated to 85 ° C. with stirring for 3 h. The catalyst is then left to mature for 18 hours. The catalyst C4 is thus obtained which contains 48% by weight of MOO3.

Example 5: Preparation of catalyst C5 according to the invention

10 g of the same support crushed to 300-500 μm used for the preparation of catalyst C1 was pre-impregnated with water by adding 5 cm ³ of water, ie 42% of the VRE. The water is poured drop by drop onto the support contained in a rotating bezel. In order to let the support soak up properly, it is placed in a ripener for 1 hour. The support pre-impregnated with water is then transferred to the reactor and 4.2 g of PMA as well as 2.5 g of cobalt nitrate hexahydrate are added. The reflux is set up and the reactor is heated to 85 ° C. with stirring for 3 h. The catalyst is then left to mature for 18 hours. Catalyst C5 is thus obtained which contains 22 wt% MoO3 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 1 according to the equation following and in relative with respect to the activity of catalysts C1, 22% by weight M0O3 prepared by dry impregnation. kHYD = WH x Ln (1 / (1 -C _Tq i _ub ™)) with X _oluene , conversion of toluene by hydrogenation The activity results are given in the following table. These results show that a catalyst prepared by melt impregnation with the same 22 wt% molybdenum oxide content is more active than the reference catalyst prepared by dry impregnation with an activity of 122.

Increasing the amount of molybdenum oxide by melt impregnation to 26 wt% gives an activity of 178.

Increasing the amount of molybdenum oxide by melt impregnation to 48 wt%, which would not be possible by dry impregnation gives an activity of 583.

The catalyst prepared by molten impregnation with cobalt and molybdenum gives an activity of 544. In addition, the preparation of catalysts according to the invention does not require a solvent, nor a drying step.

Claims

1. Process for preparing a hydrotreatment and / or hydrocracking catalyst comprising a porous support based on alumina or on silica or on silica-alumina and at least one metal from group VIB, the group metal content. VIB being between 5 and 55% by weight expressed as metal oxide of group VIB relative to the total weight of the catalyst, said process comprising the following steps: a) water is brought into contact with said porous support so as to obtain a wet porous support, b) contacting said wet porous support with at least one hydrated metallic acid comprising at least one metal from group VIB whose melting point of said hydrated metallic acid is between 20 and 100 ° C, to form a solid mixture, the mass ratio between said metallic acid and said porous support being between 0.1 and 2.5, c) the solid mixture obtained at the end of step b) is heated with stirring to a temperature of between fusi temperature on said metal acid and 100 ° 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 amount of water introduced into the support is between 10 and 70% of its water uptake volume.

4. 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, to form a solid mixture, the molar ratio (metal of group VIII) / (metal of group VIB) being between 0.1 and 0.8.

5. Method according to the preceding claim, wherein said metal salt is a hydrated nitrate salt.

6. 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.

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

8. 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.

9. 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.

10. Method according to one of the preceding claims, wherein after step c) is carried out a step d) of drying the catalyst obtained in step c) at a temperature below 200 ° C.

11. Process according to the preceding claim, in which a stage e) of calcining the catalyst obtained in stage d) is carried out at a temperature greater than or equal to 200 ° C and less than or equal to 600 ° C under an inert atmosphere or under an inert atmosphere. oxygen-containing atmosphere.

12. Method according to one of the preceding claims, wherein before step a) or after step c) an impregnation step is carried out with the aid of an impregnation solution and in which one puts in contacting said support or said catalyst 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 at a temperature below 200 ° C and optionally by a calcination step at a temperature greater than or equal to 200 ° C and less than or equal to 600 ° C under an inert atmosphere or in an oxygen-containing atmosphere.

13. Process according to the preceding claim, in which 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, y-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-pyrrolid inedione, 5-methyl-2 (3H) -furanone, 1-methyl-2-piperidinone, and 4-aminobutanoic acid.

14. Method according to one of the preceding claims, wherein the catalyst is subjected to a sulfurization step after step c) or optional steps d) and e).

15. Catalyst obtained according to the preparation process according to claims 1 to 14.

16. Use of the catalyst prepared according to one of claims 1 to 14 in a hydrotreatment and / or hydrocracking process of hydrocarbon cuts.