FR3161580A1 - PROCESS FOR PREPARING A CATALYST BASED ON FINES FROM A CATALYST LEANING RESIDUE - Google Patents

Abstract

Process for preparing a catalyst comprising a metal of Group VIB and/or a metal of Group VIII, and an oxide support: a) Fines having a D90 size less than or equal to 500 micrometers of a catalyst comprising a metal of Group VIB and/or a metal of Group VIII, and an oxide support are made available, b) A portion of the metal of Group VIB and/or a portion of the metal of Group VIII is extracted from said fines using an extraction solution comprising an acid to obtain a solution of the extracted metal(s) and a leaching residue, c) A mixture is prepared comprising said leaching residue obtained in step b) and an extrusion agent, d) The mixture is stirred, e) A neutralizing agent is optionally added, f) The mixture is shaped, g) The mixture is dried.

Description

PROCESS FOR PREPARING A CATALYST BASED ON FINES FROM A CATALYST LEANING RESIDUE Scope of the invention

The present invention relates to a process for preparing a catalyst from fines obtained from the leaching residue of a catalyst comprising at least one metal from group VIB and/or at least one metal from group VIIIB, and an oxide support. These catalysts are intended for use in hydrocarbon hydrotreating and/or hydrocracking units.

Previous art

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

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

The addition of an organic compound to hydrotreating catalysts to improve their activity has been recommended by those skilled in the art, particularly for catalysts prepared by impregnation followed by drying without subsequent calcination. These catalysts are often called "additized dried catalysts." They are known to improve the dispersion of metals on the support surface and/or to play a beneficial role during catalyst sulfidation. Numerous documents describe the use of various ranges of organic compounds as additives, such as nitrogen-containing and/or oxygen-containing organic compounds. Several patents, for example, claim the use of carboxylic acids (EP1402948, EP0482817). In particular, document EP0482817 describes citric acid, as well as tartaric, butyric, hydroxyhexanoic, malic, gluconic, glyceric, glycolic, and hydroxybutyric acids. The key difference lies in the drying process, which must be carried out at a temperature below 200°C.

During operation in hydrotreating and/or hydrocracking processes, the catalyst becomes deactivated due to the accumulation of coke and/or sulfur compounds or other heteroelements on its surface. After a certain period, its replacement is therefore necessary. One way to dispose of spent catalysts is through landfilling, but this is becoming increasingly difficult due to environmental constraints.

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

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

However, in some cases, catalysts cannot be regenerated or rejuvenated. Yet, spent catalysts from hydrocarbon hydrotreating or hydroconversion units contain metals of interest, namely at least one metal from group VIB and/or at least one metal from group VIII. Once spent, the metals contained in these catalysts are not currently recycled for the manufacture of new catalysts: they are mainly reused for the manufacture of special alloys, requiring complex purification operations, particularly to remove compounds from the recovered metals that are considered contaminating, such as arsenic, or problematic for the intended applications, such as phosphorus, the presence of which, for example, disrupts the properties of chromium steel alloys.

However, processes have been developed to recover metals from catalysts, in order to recycle them for the manufacture of new catalysts.

French patent application FR3117381 proposes the production of a recycled catalyst for the hydrotreating or hydroconversion of hydrocarbons. Group VIII and/or VIB metals are leached from an aqueous solution containing at least one organic compound with complexing properties, and possibly also acidic. The resulting solution is then used directly for impregnation onto an oxide support to produce a recycled catalyst; that is, the extracted metals remain in the liquid phase throughout the entire process. Unlike previous techniques, this process does not attempt to recover the metal in solid, monometallic form, thus avoiding numerous precipitation/filtration operations. The process is therefore easy to implement on an industrial scale.

However, at the end of this leaching stage, in addition to the leaching solution enriched with the target metals, a solid leaching residue is also recovered. This residue includes the oxide support and some of the metals that were not extracted. Given the current strong recycling focus, it would therefore be advantageous to utilize this leaching residue in the preparation of a new catalyst.

Therefore, the present invention aims to improve the recycling of catalysts through a process of preparing a catalyst from fines from a catalyst leaching residue to provide a final catalyst.

Objects of the invention

The invention proposes a method for preparing a catalyst comprising at least one metal from group VIB and/or at least one metal from group VIII, and an oxide support, said method comprising at least the following steps:

a) Fine particles having a D90 size less than or equal to 500 micrometers are made available from a source catalyst comprising at least one metal from group VIB and/or at least one metal from group VIII, and an oxide support, then

b) an extraction of part of the group VIB metal and/or part of the group VIII metal from said fines of the source catalyst is carried out by an extraction solution comprising at least one acid to obtain a solution of the extracted metal(s) and a leaching residue, then

(c) a mixture is prepared comprising said leaching residue obtained in step (b) and an extrusion aid, and optionally an inorganic oxide binder,

d) the mixture obtained in step c) is kneaded

e) Optionally, a neutralizing agent chosen from an inorganic base and an organic base is added to the mixture obtained in step d),

f) The mixture obtained in step d) or step e) is shaped by extrusion to obtain a solid,

g) the solid obtained in step f) is dried at a temperature below 200°C.

The preparation process according to the invention thus makes it possible to valorize a catalyst leaching residue to provide a new final catalyst.

It allows for the production of a catalyst from a leaching residue and optionally an inorganic oxide binder, preferably incorporating a high proportion of fines from the leaching residue. Since the active phase containing the metals is provided by the fines from the leaching residue in the final catalyst, it is advantageous to incorporate a high proportion of fines into the catalyst to achieve maximum activity and/or avoid the need to reintroduce excessive amounts of metals through subsequent impregnation. The presence of an inorganic oxide binder increases the mechanical strength (EGG) and, if necessary, reduces the macroporous volume of the catalyst obtained by the process according to the invention.

The process according to the invention also makes it possible to obtain a catalyst entirely obtained from the leaching residue (incorporation rate of 100% weight in fines from the leaching residue), that is to say a catalyst which does not contain any added inorganic oxide binder.

Furthermore, the catalyst obtained by the process according to the invention exhibits in particular a mechanical resistance (measured by EGG) and a macroporous volume compatible with its use in a hydrotreating and/or hydrocracking process.

Similarly, the concentrated extraction solution of the target metals obtained in step b) can also be used as an impregnation solution for the manufacture of another new catalyst as described in FR3117381. This means that the extracted metal(s) from the fines of the source catalyst are dissolved and remain in solution until they are reused as an addition to the impregnation solution to produce a new catalyst. The extraction solution can also be re-impregnated using the leaching residue.

The process according to the invention thus makes it possible to valorize both the extracted metal/metal(s) solution and the leaching residue for the preparation of new catalysts.

According to one variant, the process includes a step h) in which the dried solid obtained in step g) is calcined at a temperature between 200°C and 600°C.

According to one variant, the D90 size of the fines made available in step a) is less than 300 micrometers.

According to one variant, the fines made available at step a) have a group VIB metal content of between 5 and 40% by weight of group VIB metal oxide and a group VIII metal content of between 1 and 50% by weight of group VIII metal oxide relative to the weight of the fines.

According to one variant, the oxide support for the fines made available in step a) is chosen from alumina, silica, silica-alumina, titanium or magnesium oxide used alone or in a mixture with alumina or silica-alumina.

According to one variant, the acid in the extraction solution of step b) is an inorganic acid chosen from phosphoric acid, nitric acid, boric acid or sulfuric acid.

According to one variant, the acid in the extraction solution of step b) is an organic acid chosen from formic acid, acetic acid, oxalic acid, malonic acid, glutaric acid, glycolic acid, lactic acid, tartronic acid, citric acid, tartaric acid, pyruvic acid, γ-ketovaleric acid, succinic acid, acetoacetic acid, gluconic acid, ascorbic acid, phthalic acid, salicylic acid, maleic acid, malic acid, fumaric acid, acrylic acid, thioglycolic acid, 2-hydroxy-4-methylthiobutanoic acid, glutamic acid, N-acetylglutamic acid, alanine, glycine, cysteine, histidine, aspartic acid, N-acetylaspartic acid, 4-aminobutanoic acid, 1,2-cyclohexanediaminetetraacetic acid, ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), iminodiacetic acid (IDA), N-(2-hydroxyethyl)ethylenediamine-N,N′,N′-triacetic acid (HEDTA), diethylenetriaminepentaacetic acid (DTPA), bicine, tricine, 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP or etidronic acid), nitrilotris(methylenephosphonic) acid, diethylenetriaminepentakis(methylenephosphonic) acid, 4-sulfophthalic acid, 3-(N-morpholino)-2-hydroxy-1-propanesulfonic acid (MOPSO), 2-(4-Pyridinyl)ethanesulfonic acid, phenol-4-sulfonic acid, thiodiacetic acid and diglycolic acid.

According to one variant, the concentration of each acid in the extraction solution of step b) is between 0.03 and 2 mol/L.

According to one variant, the extraction solution in step b) further comprises at least one organic compound exhibiting complexing properties.

According to one variant, the loss on ignition of the leaching residue obtained in step b) is reduced by drying and/or by mixing the leaching residue with dry fines of the source catalyst and/or an inorganic oxide binder.

According to one variant, the content of extrusion aid in step c) is between 0.1 and 10% by weight relative to the weight of the dry leaching residue and the dry inorganic oxide binder when present.

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

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

According to one variant, said inorganic oxide binder is introduced into the mixture in step c) so that the content of inorganic oxide binder is less than 95% by weight relative to the weight of the dry catalyst obtained at the end of step g) of drying.

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

According to one variant, the process includes a step i) in which at least one metal from group VIB and/or at least one metal from group VIII, and optionally phosphorus and/or at least one organic compound comprising oxygen and/or nitrogen and/or sulfur, is brought into contact with the catalyst obtained after step g) of drying or after step h) of calcination, the contacting being followed by a drying step at a temperature below 200°C, and optionally by a subsequent calcination step.

According to one variant, the solution of metal(s) of group VIB and/or VIII extracted from step b) is used as an impregnation solution for a support, said extracted metal(s) remaining in liquid phase from extraction until impregnation.

Definitions

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

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

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

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

In this description, the term "extraction" is synonymous with the term "leaching," unless otherwise specified. The terms "leaching" or "extraction" in this description refer to the process of extracting one or more metals from a solid (fines of the source catalyst) by dissolving it in a liquid (leaching solution or extraction solution).

In this description, the term "leaching residue" is the solid remaining after a leaching/fines filtration operation of a source catalyst.

In this description, the term "metal/metals extracted" refers to the metals sought, i.e., metals from group VIII and/or VIB. Other metals are considered contaminants.

In this description, the term "contaminants" refers to undesirable elements in the source catalyst and in the extraction solution that are not intended to be extracted. Contaminants include, but are not limited to, nickel (from feedstock contamination) and/or vanadium and/or iron and/or titanium and/or silicon and/or calcium and/or sodium and/or potassium and/or chlorine and/or arsenic.

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

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

Elemental analyses, typically by inductively coupled plasma (ICP) spectrometry, or by X-ray fluorescence spectrometry, more commonly called X-ray fluorescence (FX), allow the content of the different elements of the fines pretreated at 550°C under air and of the extraction solution.

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

By “macropores”, we mean pores with an opening greater than 50 nm.

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

By “micropores” we mean pores with an opening of less than 2 nm.

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

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

We set at 0.2 MPa the value from which mercury fills all intergranular voids, and we consider that beyond this point mercury penetrates the pores of the sample.

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

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

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

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

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

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

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

Detailed description of the invention

The present invention relates to a process for preparing a catalyst from fines obtained from a leaching residue of a source catalyst comprising at least one metal from group VIB and/or at least one metal from group VIIIB, and an oxide support.

Step a) Provision of the fines

According to step a) of the preparation process according to the invention, fines having a D90 size less than or equal to 500 micrometers are made available to a source catalyst comprising at least one metal from group VIB and/or at least one metal from group VIII, and an oxide support.

The catalyst fines originate from a source catalyst, which can be fresh, used, regenerated and/or rejuvenated. They can also originate from a fresh, used, regenerated and/or rejuvenated capture mass.

Preferably, the fines come from a fresh or regenerated catalyst. Most preferably, the fines come from a regenerated catalyst.

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

According to a second embodiment, the fines may originate from a spent catalyst. A "spent" catalyst is understood to be one that is at least partially spent, meaning one that has already been used in production, particularly in hydrotreating or hydroconversion plants such as hydrocracking. A "spent" catalyst is specifically understood to include one that is at least partially spent but has not been regenerated or rejuvenated. The spent catalyst may contain coke and/or sulfur as described above.

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

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

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

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

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

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

Therefore, fines with a D90 size that is too large, or the catalyst used to produce fines, are subjected to a preliminary grinding step if necessary. It is, of course, possible to carry out several successive grinding steps to achieve the desired particle size D90. Any method known to those skilled in the art can be implemented to perform this crushing or grinding step, such as, for example, the use of a ball mill or a blade mill. In this case, the grinding step is carried out in such a way as to obtain fines having a D90 size less than or equal to 500 micrometers, preferably less than 300 micrometers, or even less than 200 micrometers, preferably between 1 and 500 micrometers, preferably between 1 and 300 micrometers, preferably between 1 and 200 micrometers, or even between 1 and 160 micrometers or between 1 and 100 micrometers, even more preferably between 1 and 60 micrometers, and particularly preferably between 1 and 20 micrometers. The D90 size is defined as follows: 90% of the volume population of fines has an equivalent diameter less than or equal to 500 micrometers, preferably less than 300 micrometers, or even less than 200 micrometers, and generally between 1 and 500 micrometers, preferably between 1 and 300 micrometers, preferably between 1 and 200 micrometers, or even between 1 and 160 micrometers or between 1 and 100 micrometers, even more preferably between 1 and 60 micrometers, and particularly preferably between 1 and 20 micrometers. The equivalent diameter, denoted "de", is defined according to the following relationship: de = 6V/S, where V is the volume of the particle and S is the surface area of the sphere with the same volume as the particle.

The particle size distribution of fines is measured by laser diffraction particle size analysis according to ASTM D4464. This technique is based on the principle of light diffraction. Suspended particles (in a solvent such as water or in an air stream) diffract the light emitted by a laser beam contained within the instrument. The spatial distribution of this light, a function of particle size, is recorded by an array of photodiodes. Analysis of this distribution in the focal plane allows the proportion of each size class to be determined, leading to knowledge of the particle size distribution within the sample.

Before any grinding to produce fines of suitable size, the source catalyst may undergo at least one pretreatment step prior to the process according to the invention. This optional pretreatment step consists of removing all or part of one or more impurities that may be present in the source catalyst, using any method known to those skilled in the art. The pretreatment step may include oil removal, regeneration, or water washing. These preliminary treatments aim to improve the efficiency of extraction through mechanical, physical, or chemical processes. Preferably, the pretreatment step includes a regeneration step to remove all or part of the coke, sulfur, and/or chlorine, as detailed below.

Degreasing

The discharge of the source catalyst from a hydrotreating and/or hydroconversion process is preferably preceded by a de-oiling step. The de-oiling step generally involves contacting the catalyst with a stream of inert gas (i.e., essentially oxygen-free), for example, in a nitrogen or similar atmosphere, at a temperature between 300°C and 400°C, preferably between 300°C and 350°C. The inert gas flow rate, expressed as a flow rate per unit volume of catalyst, is 5 to 150 NL· ^h⁻¹ for 3 to 7 hours. Alternatively, the de-oiling step can be carried out using light hydrocarbons, by steam treatment, or any other similar process.

The degreasing stage is generally followed by a drying stage and/or a heating stage, preferably at a temperature between 50°C and 200°C.

The drying gas is preferably an inert gas such as nitrogen.

Regeneration

The source catalyst, possibly de-oiled, can be subjected to a coke and sulfur removal step: a regeneration step, which allows the removal of all or part of the coke, sulfur and/or chlorine possibly deposited on the source catalyst.

Although possible, regeneration is preferably not carried out by keeping the loaded catalyst in the hydrotreating reactor (in-situ regeneration). Preferably, the source catalyst is therefore extracted from the reactor and sent to a regeneration facility to perform the regeneration there (ex-situ regeneration).

The regeneration step is generally carried out in a gas stream containing oxygen, usually air. The water content in the gas is generally between 0 and 50% by weight. The gas flow rate, measured in terms of flow rate per unit volume of the source catalyst and/or source catalyst fines, is preferably 20 to 2000 NL· ^h⁻¹ , more preferably 30 to 1000 NL·h⁻¹, and particularly preferably 40 to 500 NL· ^h⁻¹ . The regeneration time is preferably 2 hours or more, more preferably 2.5 hours or more, and particularly preferably 3 hours or more. Regeneration is generally carried out at a temperature between 320°C and 550°C, preferably between 360°C and 500°C.

The regenerated catalyst consists of the oxide support and the active phase, which is composed of at least one metal from Group VIB and/or at least one metal from Group VIII, and optionally phosphorus from the source catalyst. The regenerated catalyst contains substantially the same amount of Group VIB and/or VIII metal as the source catalyst. The regenerated catalyst contains substantially the same amount of contaminants, with the exception of coke, sulfur, and chlorine.

The regenerated catalyst is characterized by a specific surface area of between 20 and 400 m²/g, preferably between 30 and 280 m²/g, preferably between 40 and 260 m²/g, most preferably between 80 and 250 m²/g.

The porous volume of the regenerated catalyst is generally between 0.1 ^cm³ /g and 1.3 ^cm³ /g, preferably between 0.2 ^cm³ /g and 1.1 ^cm³ /g.

The regenerated catalyst obtained in the regeneration step contains residual carbon at a level preferably less than 5 wt%, preferably between 0.1% and 4 wt%, preferably between 0.1% and 2 wt%, and most preferably between 0.1% and 1 wt%, or even between 0.1% and 0.5 wt%, relative to the total weight of the regenerated catalyst. It should be noted that the term "residual carbon" in this application means carbon (coke) remaining in the regenerated catalyst after regeneration of the source catalyst. This residual carbon content in the regenerated catalyst is measured according to ASTM D5373. The sulfur content after regeneration is preferably less than 5 wt%, preferably between 0.1% and 3 wt%, preferably between 0.1% and 2 wt%, and most preferably between 0.1% and 0.8 wt%. The chlorine content after regeneration is preferably between 0 and 0.2% by weight, expressed as an element relative to the weight of the catalyst, and preferably between 0 and 0.1% by weight. The regenerated catalyst may also be free of coke, sulfur, and/or chlorine.

Wash with water

The source catalyst, possibly de-oiled and/or regenerated and/or ground, may undergo a water washing step.

The volume of water used in this washing step is advantageously greater than the total pore volume of the source catalyst. This volume can, in particular, be within a range of 2 to 20 times the total pore volume of the source catalyst, preferably between 5 and 10 times said pore volume.

The washing step can be carried out at any suitable temperature, for example between 5°C and 150°C, preferably between room temperature (20°C) and 70°C.

During the washing stage, it is advantageous to stir the source catalyst to ensure effective washing. The washing stage can be carried out continuously or batchwise, with batch mode being preferred as it limits the amount of water used. The washing stage can be performed in any type of solid/liquid extractor or industrial mixer.

The fines from the source catalyst can also be subjected to water washing, carried out in the same way as described above.

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

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

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

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

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

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

The specific surface area of the oxide support is advantageously between 5 and ^{400 m².g⁻¹ ,} preferably between 10 and ^{350 m².g⁻¹} , and more preferably between 40 and 350 ^m².g⁻¹ . The specific surface area is determined in the present invention by the BET method according to ASTM ^D3663 .

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

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

The metal content of group VIB is between 5 and 40 wt% of the oxide of the group VIB metal relative to the total weight of the fines, preferably between 8 and 35 wt%, and most preferably between 10 and 30 wt%. When the metal is molybdenum or tungsten, the metal content is expressed as _MoO₃ and _WO₃ , respectively.

The molar ratio of group VIII metal to group VIB metal in fines is preferably between 0.1 and 0.8, preferably between 0.15 and 0.6 and even more preferably between 0.2 and 0.6 or between 0.3 and 0.5.

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

The phosphorus content is then preferably between 0.1 and 20% _by weight expressed as _P2O5 relative to the total weight of fines, preferably between 0.2 and 15% _by weight expressed as _P2O5 , and very preferably between 0.3 and 10% by weight expressed as _{P2O5 .}

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

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

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

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

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

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

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

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

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

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

Preferably, the fines are not contaminated, meaning they contain less than 100 ppm by weight of silicon (excluding any silicon present in the oxide support), less than 100 ppm by weight of sodium (excluding any sodium present in the oxide support), less than 50 ppm by weight of arsenic, less than 50 ppm by weight of iron, less than 50 ppm by weight of chlorine, less than 2000 ppm by weight of vanadium, and less than 2000 ppm by weight of nickel (contamination). This can be the case, in particular, when the fines originate from a fresh or regenerated catalyst.

All contents (active phase, phosphorus, sulfur, coke, contaminants) are given on the basis of the dry fines weight.

Step b) of extraction

According to step b) of the preparation process according to the invention, an extraction of part of the metal of group VIB and/or part of the metal of group VIII is carried out from said fines of the source catalyst by an extraction solution comprising at least one acid to obtain a solution of extracted metal(s) and a leaching residue.

The extraction solution according to the present invention may comprise any polar protic solvent known to those skilled in the art. Preferably, a polar protic solvent is used, for example, one chosen from the group consisting of methanol, ethanol, and water, or a water-ethanol or water-methanol mixture. Most preferably, the solvent used in the extraction solution is water. In the case of an aqueous solution, the pH of said solution may be modified by the optional addition of an acid or a base. The extraction solution generally has a pH between 0.1 and 8.5, preferably between 0.5 and 6, and most preferably between 1 and 4.

The extraction solution includes at least one acid, which can be chosen from an inorganic acid and/or an organic acid.

According to one variant, the metals are extracted using a solution comprising a solvent, particularly an aqueous one, and at least one inorganic acid. The inorganic acid may be chosen from phosphoric acid, nitric acid, boric acid, or sulfuric acid. Preferably, the inorganic acid is chosen from phosphoric acid, sulfuric acid, and nitric acid.

According to a second variant, the extraction of metals is carried out with a solution comprising a solvent, in particular aqueous, and at least one organic acid.

It is worth noting that the organic acids that yield the most promising results are those with complexing properties. Indeed, the organic acid protonates the metal oxide, thus limiting its interaction with the support and promoting its dissolution in the extraction solution. The acid's complexing function, in turn, allows the formation of a metal complex soluble in the extraction solution. The combination of acidic and complexing properties is therefore particularly advantageous.

The organic acid exhibiting both acidic and complexing properties may be chosen from at least one of the following compounds: formic acid, acetic acid, oxalic acid, malonic acid, glutaric acid, glycolic acid, lactic acid, tartronic acid, citric acid, tartaric acid, pyruvic acid, γ-ketovaleric acid, succinic acid, acetoacetic acid, gluconic acid, ascorbic acid, phthalic acid, salicylic acid, maleic acid, malic acid, fumaric acid, acrylic acid, thioglycolic acid, 2-hydroxy-4-methylthiobutanoic acid, glutamic acid, N-acetylglutamic acid, alanine, glycine, cysteine, histidine, aspartic acid, N-acetylaspartic acid, 4-aminobutanoic acid, 1,2-cyclohexanediaminetetraacetic acid, ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), iminodiacetic acid (IDA), N-(2-hydroxyethyl)ethylenediamine-N,N′,N′-triacetic acid (HEDTA), diethylenetriaminepentaacetic acid (DTPA), bicine, tricine, 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP or etidronic acid), nitrilotris(methylenephosphonic) acid, diethylenetriaminepentakis(methylenephosphonic) acid, 4-sulfophthalic acid, 3-(N-morpholino)-2-hydroxy-1-propanesulfonic acid (MOPSO), 2-(4-Pyridinyl)ethanesulfonic acid, phenol-4-sulfonic acid, thiodiacetic acid and diglycolic acid.

According to a preferred variant, the organic compound is chosen from a carboxylic acid that preferably comprises between 1 and 8 carbon atoms and that may be a mono-, di-, or tri-acid. Preferably, the organic compound is chosen from acetic acid, glutaric acid, oxalic acid, glycolic acid, lactic acid, citric acid, γ-ketovaleric acid, acetoacetic acid, and gluconic acid.

According to a third variant, the extraction of metals is carried out with a solution comprising a solvent, in particular aqueous, at least one organic acid and at least one inorganic acid.

The concentration of each acid in the extraction solution is defined so that the molar ratio of acid to extracted metals is between 0.1 and 25, preferably between 0.1 and 11, preferably between 0.1 and 5, preferably between 0.1 and 3, and preferably between 0.1 and 2.

When several acids are present, the different molar ratios apply to each of the acids present.

The concentration of each acid in the extraction solution is generally between 0.03 and 2 mol/L, preferably between 0.03 and 1.3 mol/L, and particularly preferably between 0.03 and 1 mol/L.

In one embodiment according to the invention, the extraction solution may also contain, in addition to an acid, at least one organic compound having complexing (but not acidic) properties.

The organic compound (or at least one of them when there are several) exhibiting complexing properties may be chosen from at least one of the following compounds: dimethylglyoxime, methyl acetoacetate, ethyl acetoacetate, ethyl lactate, methyl glycolate, ethyl glycolate, dimethyl malate, diethyl malate, dimethyl tartrate, diethyl tartrate, ethyl 3-hydroxybutanoate, ethyl 3-ethoxypropanoate, methyl 3-methoxypropanoate, methyl 3-(methylthio)propanoate, ethyl 3-(methylthio)propanoate, ethylene glycol, diethylene glycol, triethylene glycol, a polyethylene glycol (with a molecular weight between 200 and 1500 g/mol), the propylene glycol, glycerol, 2-butoxyethanol, 2-(2-butoxyethoxy)ethanol, 2-(2-methoxyethoxy)ethanol, triethylene glycol dimethyl ether, a crown ether, acetophenone, 2,4-pentanedione, pentanone, glucose, fructose, sucrose, sorbitol, xylitol, mannitol, γ-valerolactone, propylene carbonate, octylamine, N,-diethylformamide, N,N-dimethylformamide, N-methylformamide, N,N-dimethylacetamide, propanamide, 1-methyl-2-pyrrolidinone, tetramethylurea, N,N′-dimethylurea, acetonitrile, lactamide, furfurol, 2-furaldehyde, the 5-hydroxymethylfurfural, ethyl 3-hydroxybutanoate, 2-hydroxyethyl acrylate, 1-vinyl-2-pyrrolidinone, N,N,N’,N’-tetramethyltartramide, 3-hydroxypropionitrile and N,N’-bis(2-hydroxyethyl)ethylenediamine.

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

The concentration of each organic compound exhibiting complexing properties of the extraction solution is defined so that the molar ratio of organic compound to extracted metals is between 0.1 and 25, preferably between 0.2 and 11, preferably between 0.2 and 5, preferably between 0.3 and 3, and preferably between 0.4 and 2.

When several organic compounds with complexing properties are present, the different molar ratios apply to each of the organic compounds present.

The concentration of each organic compound exhibiting complexing properties in the extraction solution is generally between 0.03 and 2 mol/L, preferably between 0.1 and 1.3 mol/L, and particularly preferably between 0.5 and 1 mol/L.

In one embodiment according to the invention, the extraction solution may also contain an oxidant to promote metal extraction. Preferably, the oxidant in the extraction solution is hydrogen peroxide. When an oxidant is present, the concentration is generally between 0.1 and 5.0 mol/L.

The fines are brought into contact with the extraction solution under the following conditions:

The temperature is generally between 0 and 300°C, preferably between 10 and 100°C, and most preferably between 15 and 40°C. Most preferably, the temperature is ambient temperature.

The pressure is generally between atmospheric pressure and 20 bars (2 MPa), specifically between atmospheric pressure and 10 bars (1 MPa).

The contact time per extraction stage is generally between 1 minute and 20 hours, preferably between 5 and 300 minutes, and preferably between 5 and 120 minutes.

The extraction step is carried out by contacting the fines of the source catalyst with a volume of said solution between 1.5 and 60 times the volume of the fines. Preferably, the volume of said solution is between 2 and 30 times the volume of the fines, and more preferably between 2 and 20 times the volume of the fines, and particularly preferably between 2 and 10 times the volume of the fines.

According to the present invention, "extraction" is understood to mean that there is an extraction step, but that the extraction can be carried out by one extraction operation or a plurality of successive extraction operations.

All contact methods, whether single-step or multi-step (co-current, counter-current, or cross-current), are possible for implementing the continuous extraction step. The extraction step includes contacting the extraction solution with the fines from the source catalyst, followed by a solid/liquid separation step.

The contacting of the extraction solution with the fines of the source catalyst can be done by any method known to those skilled in the art, for example by suspending the fines of the source catalyst in the extraction solution by means of a rotary agitator or by fluidization, or by percolation of the leaching solution through a fixed bed containing the fines of the source catalyst.

Liquid/solid separation can be carried out by any method known to those skilled in the art, for example by sedimentation, filtration, dewatering (e.g., gravity drainage), and/or centrifugation. The remaining leaching residue can be washed with the extraction solvent and/or water.

According to one embodiment, when the fines of the source catalyst contain only a metal from group VIB or a metal from group VIII, respectively, only a metal from group VIB or a metal from group VIII is extracted from the fines. According to another embodiment, when the fines of the source catalyst contain at least one metal from group VIB and at least one metal from group VIII, either only the metal from group VIB or group VIII, respectively, or both the metal from group VIB and the metal from group VIII are extracted.

The extraction rate of Group VIII metal is generally greater than 50%, preferably greater than 60%, and preferably greater than 70%. Preferably, the extraction rate of Group VIII metal is between 50 and 95%, preferably between 60 and 95%, and preferably between 70 and 90%.

The extraction rate of the metal in group VIB is generally greater than 50%, preferably greater than 60%, and preferably greater than 70%. Preferably, the extraction rate of the metal in group VIB is between 50 and 95%, preferably between 60 and 95%, and preferably between 70 and 90%.

The extraction rate corresponds to the mass of the metal(s) extracted in the extraction solution relative to the mass of metal(s) initially present on the fines of the source catalyst.

Preferably, the residual content of group VIII and/or VIB metals of the leaching residue (sum of the contents of the different metals contained in the leaching residue expressed as oxide) is less than 20% by weight, preferably less than 10% by weight and very preferably less than 5% by weight relative to the weight of the leaching residue, it being understood that it is greater than 0% by weight.

Thus, the fines of leaching residues generally have a group VIB metal content of between 0.5 and 15% weight of oxide of group VIB metal and a group VIII metal content of between 0.5 and 5% weight of oxide of group VIII metal relative to the weight of the fines of the dry leaching residue.

At the end of the extraction step, we obtain, on the one hand, the leaching residue depleted in metal(s) of group VIII and/or VIB, and, on the other hand, the extraction solution enriched in at least one metal of group VIB and/or at least one metal of group VIII.

The extraction solution enriched in at least one metal from group VIB and/or at least one metal from group VIII can be used as an impregnation solution for a support as described below.

The leaching residue recovered at the end of the extraction step including liquid/solid separation includes in particular the oxide support and part of the group VIII and/or VIB metal(s) from the fines of the source catalyst, as well as water and residues of the acid used as an extraction agent.

The leaching residue obtained after the liquid/solid separation of the extraction step b) is wet and generally has a loss on ignition of between 50 and 80%, preferably between 50 and 60%, depending on the solid/liquid separation technique of the extraction step.

When the loss on ignition of said leaching residue obtained in step b) is too high to permit shaping by mixing-extrusion, its loss on ignition can be reduced.

This reduction in loss on ignition can be achieved in various ways, including by drying and/or mixing the leaching residue with dry fines of the source catalyst and/or an inorganic oxide binder.

According to a first variant, loss on ignition reduction is achieved by drying, by heating in the presence of a gas. Drying is generally carried out at a temperature below 200°C, advantageously between 50°C and 180°C, preferably between 70°C and 150°C, and most preferably between 80°C and 140°C. Drying can be carried out by any technique known to those skilled in the art. It is advantageously carried out at atmospheric pressure or reduced pressure. Preferably, drying is carried out at atmospheric pressure. It is advantageously carried out in a flow bed using air or any other hot gas. Preferably, when drying is carried out in a fixed bed, the gas used is either air or an inert gas such as argon or nitrogen. Most preferably, drying is carried out in a flow bed in the presence of nitrogen and/or air. Preferably, the drying time is between 5 minutes and 24 hours, preferably between 30 minutes and 10 hours, and most preferably between 1 hour and 8 hours.

According to a second embodiment, the loss on ignition reduction is achieved by mixing the leaching residue, possibly dried, with dry fines from the source catalyst or any other catalyst. The loss on ignition of the leaching residue is thus reduced by the addition of dry matter. The dry fines content of the source catalyst added to this mixture is generally between 1 and 95% by weight, preferably between 1 and 50% by weight, relative to the weight of the dry leaching residue. The addition of dry fines from the source catalyst (unleached) simultaneously increases the content of Group VIB metal and/or Group VIII metal in the final catalyst obtained by the process according to the invention.

According to a third variant, loss on ignition is reduced by mixing the leachate residue, possibly dried, with an inorganic oxide binder as described below. The loss on ignition of the leachate residue is thus reduced by the addition of dry matter. The binder content added to this mixture is generally between 1 and 95% by weight, preferably between 1 and 50% by weight, relative to the weight of the dry leachate residue.

Step c) Mixing of the leaching residue and extrusion aid

According to step c) of the process according to the invention, a mixture is prepared comprising said leaching residue obtained in step b) and an extrusion aid agent, and optionally an inorganic oxide binder.

The leaching residue and the agent, and optionally the binder, may be mixed, without limitation, in the form of powder, ground powder, suspension, or suspension that has undergone a deagglomeration treatment. Said leaching residue and the agent, and optionally the binder, may advantageously be mixed by mechanical blending or by suspension to a concentration adjusted to the final leaching residue content and optionally the binder content targeted in the catalyst prepared according to the present invention.

The extrusion aid facilitates subsequent extrusion. The content of the extrusion aid is between 0.1 and 10% by weight, preferably between 1 and 5% by weight, and even more preferably between 0.1 and 3% by weight, relative to the weight of the dry leaching residue and the dry inorganic oxide binder when present.

The extrusion aid can be methylcellulose, for example Methocel™, cellulose, carboxy-methyl-cellulose or carboxy-ethyl-cellulose. Preferably, the extrusion aid is methylcellulose (Methocel™).

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

The inorganic oxide binder may advantageously be amorphous or crystalline. This binder is advantageously selected from the group formed by the following oxides or their hydrated forms: alumina, silica, silica-alumina, clays, titanium dioxide, boron dioxide, and zirconia, alone or in mixtures. Preferably, the binder is alumina or an aluminum hydroxide, alone or in mixtures. Preferably, the binder is alumina in all its forms known to those skilled in the art, such as, for example, alpha, gamma, eta, and delta aluminas, or hydroxides such as boehmite, bayerite, or gibbsite. These aluminas differ in their specific surface area and pore volume. Preferably, the inorganic oxide binder is alumina or boehmite. In a particularly preferred manner, the inorganic oxide binder is similar or identical to the oxide support contained in the fines of the leaching residue.

The leaching residue is introduced into the mixture in step c) such that its content is between 5% and 100% by weight of the dry catalyst obtained after drying step g), preferably between 50% and 100% by weight, and most preferably between 75% and 100% by weight. The leaching residue content is expressed on a weight basis of dry leaching residue. Since the active phase is provided by the leaching residue in the catalyst obtained according to the process of the invention, it is advantageous to incorporate a high percentage of the leaching residue into the catalyst in order to obtain the highest possible activity and/or to avoid having to reintroduce excessive amounts of metals subsequently.

When used, the inorganic oxide binder is introduced into the mixture in step c) such that the inorganic oxide binder content is less than 95% by weight, preferably between 0% and 95% by weight relative to the weight of the dry catalyst obtained at the end of drying step g), preferably between 10% and 50% by weight, and most preferably between 10% and 25% by weight. The inorganic oxide binder content is expressed on a weight basis of the dry binder.

Step d) Mixing

According to step d) of the process according to the invention, the mixture obtained in step c) is kneaded. A paste is thus obtained.

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

The kneading time is generally between 1 minute and 1 hour, preferably between 5 and 30 minutes.

In conventional kneading-extrusion processes, a peptizing agent is usually added, resulting in a paste that is subsequently extruded. Generally, the peptizing agent is an acid, such as nitric acid or citric acid. Since the leaching residue obtained in extraction step b) already contains at least one acid, the addition of a peptizing agent is generally unnecessary. However, the amount of acid (peptizing agent) can be adjusted if required. The total acid content, expressed as a percentage relative to the weight of the dry leaching residue and any dry binder present, is between 0.1 and 10% by weight, preferably between 0.1 and 9% by weight, and most preferably between 0.1 and 8% by weight.

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

Step e) of neutralization (optional)

An optional neutralization step e) can be carried out after the mixing step d) by adding to the mixture obtained in step d) a neutralizing agent chosen from an inorganic base or an organic base.

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

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

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

When the neutralization step by adding the neutralizing agent is carried out, the mixing is maintained under the conditions described above.

Step f) Shaping by extrusion

According to step f) of the process according to the invention, the mixture obtained in step d) of mixing or in the optional step e) of neutralization is shaped by extrusion to obtain a solid.

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

Step g) Drying

According to step g) of the process, the solid obtained in step f) of extrusion is dried at a temperature below 200°C, advantageously between 50°C and 180°C, preferably between 70°C and 150°C, most preferably between 80°C and 140°C.

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

Optionally, the drying step can be followed by a calcination step as described below. This might be the case, for example, if it is desired to remove all or part of the acid used in step b) of extraction.

When the extraction step has been carried out with an inorganic acid, the calcination step described below is preferably performed. Here, calcination is defined as heat treatment under a gas containing air or oxygen at a temperature of 200°C or higher.

When the extraction step has been carried out with an organic acid, a calcination step is preferably not performed. In this case, the drying is advantageously conducted in such a way as to retain preferably at least 30% by weight of the organic acid introduced during the extraction step, preferably this quantity is greater than 50% by weight and even more preferably greater than 70% by weight, calculated on the basis of the carbon remaining on the catalyst obtained.

Step h) Calcination (optional)

According to the optional step h) of the process according to the invention, the solid obtained in step g) is calcined at a temperature between 200°C and 600°C, preferably between 300°C and 550°C, and particularly preferably between 400°C and 550°C.

Calcination can be carried out under an inert atmosphere (nitrogen, for example) or under an oxygen-containing atmosphere (air, for example). The duration of this heat treatment is generally between 0.5 and 16 hours, preferably between 1 and 5 hours.

At the end of step g) of drying or step h) of calcination where it takes place, the catalyst is advantageously subjected to a sulfidation step as described below.

Step i) Introduction of active phase (optional)

Depending on the application of the catalyst and its target metal contents of groups VIB and/or VIII, the process according to the invention may include a step i) of introducing one or more precursors of an active phase onto the catalyst obtained in step g) of drying or in step h) of calcination.

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

The metal from group VIB and/or the metal from group VIII introduced in this step (i) may be the same as, or different from, the metal from group VIB and the metal from group VIII already introduced in the fines. A metal not present in the fines supplied in step (a) of the process may be introduced.

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

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

The contacting process advantageously involves a precursor of said metals.

For example, sources of molybdenum include oxides and hydroxides, molybdic acids and their salts, particularly ammonium salts such as ammonium molybdate, ammonium heptamolybdate, _{phosphomolybdic} acid ( _{H₃PMo₁₂O₄O} ), and their salts, and possibly _{silicomolybdic acid (H₄SiMo₁₂O₄O )} and its salts. Molybdenum sources can also include any heteropolycompound of the Keggin, _lacunar Keggin, substituted Keggin, _Dawson , Anderson, and Strandberg types, for example. Molybdenum trioxide and heteropolycompounds of the Keggin, lacunar Keggin, substituted Keggin, and Strandberg types are preferred.

The tungsten precursors that can be used are also well known to those skilled in the art. For example, tungsten sources include oxides and hydroxides, tungstic acids and their salts, particularly ammonium salts such as ammonium tungstate, ammonium metatungstate, phosphotungstic acid and their salts, and possibly _{silicotungstic acid (H₄SiW₁₂O₄O )} and its salts. Tungsten sources can also be any heteropolycompound of the Keggin, lacunar Keggin, substituted Keggin, or Dawson type, for example. Ammonium oxides and salts such as ammonium metatungstate or heteropolyanions of the Keggin, _lacunar Keggin, or substituted Keggin type are preferred.

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

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

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

According to another variant, the contacting step i) may also include contacting said catalyst obtained in the drying step g) or the calcination step h) with an impregnation solution containing phosphorus, in addition to the metal of group VIB and/or the metal of group VIII.

The total molar ratio of phosphorus to the metal of group VIB in the catalyst is greater than or equal to 0.05, preferably greater than or equal to 0.07, preferably between 0.08 and 3, preferably between 0.1 and 2.5 and most preferably between 0.15 and 2.

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

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

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

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

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

Preferably, it is chosen from among γ-valerolactone, 2-acetylbutyrolactone, triethylene glycol, diethylene glycol, ethylene glycol, ethylenediaminetetraacetic acid (EDTA), formic acid, acetic acid, oxalic acid, maleic acid, malonic acid, citric acid, gluconic acid, dimethyl succinate, glucose, fructose, sucrose, sorbitol, xylitol, γ-ketovaleric acid, dimethylformamide, 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, 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.

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

The organic compound introduced in this way may be identical or different from the organic acid introduced in step b) of extraction and/or identical or different from the organic compound having complexing properties possibly introduced in step b).

According to yet another variant, the contacting step i) may also include contacting said catalyst obtained in the drying step g) or the calcination step h) with the metal extraction solution from step b).

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

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

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

After the impregnation step(s) and the possible maturation step(s), the catalyst is generally dried at a temperature below 200°C, advantageously between 50°C and 180°C, preferably between 70°C and 150°C, most preferably between 75°C and 130°C, in order to obtain a dried catalyst.

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

According to one variant and advantageously when an organic compound is present, either added in step i), or an organic acid and possibly an organic compound with complexing properties introduced during the extraction step, the drying is carried out in such a way as to retain preferably at least 30% by weight of the organic compound introduced during an impregnation step, preferably this quantity is greater than 50% by weight and even more preferably greater than 70% by weight, calculated on the basis of the carbon remaining on the catalyst.

Optionally, drying can be followed by a calcination step. In this variant, after the drying step, a calcination step is carried out at a temperature between 200°C and 600°C, preferably between 250°C and 550°C, under an inert atmosphere (e.g., nitrogen) or an oxygen-containing atmosphere (e.g., air). The duration of this heat treatment is generally between 0.5 and 16 hours, preferably between 1 and 5 hours. After this treatment, the active phase is generally in oxide form; the heteropolyanions are thus transformed into oxides. Similarly, the catalyst contains little or no organic additive. However, the introduction of the organic additive during its preparation has increased the dispersion of the active phase, thus resulting in a more active catalyst.

When an organic compound is present, either added in step i), or an organic acid and possibly an organic compound with complexing properties introduced during the extraction step, calcination is preferably not carried out in order to preserve at least part of the organic/acid compound in the catalyst. Here, calcination is defined as heat treatment under a gas containing air or oxygen at a temperature of 200°C or higher.

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

At the end of step g) of drying or step h) of calcination of the process according to the invention, or after the possible introduction of active phase of step i) followed by a drying step and a possible calcination step, said catalyst is therefore advantageously subjected to a sulfidation step.

The catalyst is advantageously sulfided ex situ or in situ . Sulfurizing agents include hydrogen sulfide ( _H₂S ), elemental sulfur, _CS₂ , mercaptans, sulfides and/or polysulfides, hydrocarbon fractions with a boiling point below 400°C containing sulfur compounds, or any other sulfur-containing compound used for activating hydrocarbon feedstocks to sulfidate the catalyst. These sulfur-containing compounds are advantageously selected from alkyl disulfides, such as dimethyl disulfide (DMDS), alkyl sulfides, such as dimethyl sulfide, thiols, such as n-butylmercaptan (or 1-butanethiol), and polysulfide compounds of the tertiononyl polysulfide type. The catalyst can also be sulfided with sulfur contained in the feedstock to be desulfurized. Preferably, the catalyst is sulfided in situ in the presence of a sulfurizing agent and a hydrocarbon feedstock. Most preferably, the catalyst is sulfided in situ in the presence of a hydrocarbon feedstock supplemented with dimethyl disulfide.

Characteristics of the catalyst obtained

The preparation process according to the present invention makes it possible to obtain a catalyst comprising at least one oxide support (from the fines introduced in step a), optionally supplemented with the inorganic oxide binder from step c), at least one metal from Group VIII and/or at least one metal from Group VIB (from the fines introduced in step a), or introduced in step i)), an acid (from the leaching residue) and optionally phosphorus (from the leaching residue or possibly introduced in step i) and optionally an organic compound comprising oxygen and/or nitrogen and/or sulfur (from the leaching residue or introduced in step i) or introduced in step b)). The catalyst obtained according to the process of the invention may also include, but not limited to, coke and/or sulfur, particularly when it is derived from a leaching residue of a regenerated or spent catalyst.

The Group VIII metal content is between 0.5 and 50% by weight of Group VIII metal oxide relative to the weight of the catalyst, preferably between 1 and 9% by weight, and preferably between 1.5 and 8% by weight.

The metal content of group VIB is between 2 and 40% by weight of oxide of group VIB metal relative to the weight of the catalyst, preferably between 4 and 35% by weight, most preferably between 5 and 30% by weight.

The molar ratio of group VIII metal to group VIB metal in the catalyst is preferably between 0.1 and 0.8, preferably between 0.15 and 0.6 and even more preferably between 0.2 and 0.6 or between 0.3 and 0.5.

The phosphorus content is then preferably between 0.05 and 20% _by weight expressed as _P2O5 relative to the weight of the catalyst, preferably between 0.2 and 15% _by weight expressed _{as P2O5} , and very preferably between 0.3 and 10% by weight expressed as _P2O5 .

The molar ratio of phosphorus to the element in group VIB is greater than or equal to 0.05, preferably greater than or equal to 0.07, preferably between 0.08 and 3, preferably between 0.01 and 2.5 and most preferably between 0.15 and 2.

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

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

The different contents (active phase, phosphorus, sulfur, coke) are expressed in relation to the weight of the dry catalyst.

The preparation process according to the present invention has in particular the advantage of leading to a catalyst having a very satisfactory mechanical resistance in relation to the porous volumes which characterize it, said resistance being materialized by the value of the grain-to-grain EGG crushing of at least 0.4 daN/mm, preferably of at least 0.6 daN/mm, most preferably of at least 0.7 daN/mm.

The preparation process according to the present invention allows obtaining a catalyst advantageously having a total pore volume, as measured by mercury porosimeter intrusion, of between 0.1 and 1.5 ml/g and preferably between 0.2 and 1.1 ml/g.

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

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

The catalyst prepared according to the invention generally has a specific surface area of between 5 and 400 m²/g, preferably between 10 and 350 m²/g, preferably between 40 and 350 m²/g, most preferably between 150 and 340 m²/g.

Valorization of the metal/metals enriched extraction solution

The extraction solution enriched in at least one metal from group VIB and/or at least one metal from group VIII obtained in step b) of extraction can be valorized.

According to one embodiment, the extracted metal(s) contained in the extracted metal(s) solution can be recovered in solid form. Recovery in solid form can be carried out by any method known to those skilled in the art, for example by precipitation/filtration, crystallization/filtration, or a liquid/liquid extraction treatment followed by solvent evaporation, or by adsorption onto a collection mass.

According to another, preferred embodiment, the extracted metal(s) solution can be used as an impregnation solution to prepare a new catalyst as described in FR3117381, i.e., without intermediate treatment where the extracted metal(s) would be in solid phase, nor with liquid/liquid extraction treatment. In this case, the extracted metal(s) contained in the extracted metal(s) solution remain in solution until they are reused as a top-up impregnation solution to produce a new catalyst. This allows for "direct" valorization, thus avoiding a number of precipitation/filtration operations, making the production of a new catalyst easy to implement on an industrial scale.

Before its use as an impregnation solution, the extracted metal(s) solution may be subjected to at least one treatment step chosen from at least one of the following: purification, concentration, dilution, modification of the solution's composition by the addition or removal, total or partial, of at least one compound. The extracted metal(s) remain in the liquid phase during these treatments.

The purpose of purification is to remove all or part of any impurities that may be present in the metal solution, particularly those originating from impurities potentially present on the spent catalyst or resulting from partial dissolution of the catalyst support. Purification can be carried out in a single step or in several successive steps. If the extracted metal(s) solution contains suspended solids after the final liquid/solid separation step, any known method for removing these suspended solids may be used. Preferably, this removal is achieved by filtration (for example, microfiltration and ultrafiltration using a cross-flow filter). Other methods include centrifugation, coagulation, or sedimentation. For dissolved impurities, such as arsenates or arsenites, all known methods may be used, particularly and preferably, solid sorption, precipitation, and solvent extraction, taking care not to simultaneously remove the extracted metals of interest.

The extracted metal(s) solution, possibly purified, may undergo a concentration step. This step consists of concentrating the extracted metal(s) solution by removing some of the solvent and possibly all or part of the acid contained in the metal solution. This step may be necessary if the metal concentrations are too low compared to the concentrations required for impregnation. Any known method for removing some of the solvent from a solution is considered. The concentration may be carried out in a single step or in several successive steps. All or part of the solvent, with or without acid, extracted from the metal solution may be recycled in the process according to the invention as a leaching solution.

Preferably, and particularly when the metal solution is aqueous, concentration is achieved by evaporation. In this case, neutralization is preferably carried out so that the effluent enters the evaporator at a pH between 5 and 7. This pH control helps limit co-distillation, unless it is desired for the co-removal of the solvent and some of the acid, and also to minimize the precipitation of metal oxides. Preferably, all or part of the distillate can be recycled in the process according to the invention as a leaching solution.

When only partial solvent removal is desired, in addition to evaporation, the preferred techniques are membrane techniques, and, even more importantly, nanofiltration, reverse osmosis and pervaporation, solvent extraction, and cryoconcentration. When both solvent and acid removal are required, evaporation is a preferred technique.

The extracted metal(s) solution, possibly purified and/or concentrated, may undergo a composition adjustment step. This step involves modifying the metal solution by adding and/or removing certain constituents. Metal precursors and/or phosphorus precursors and/or organic additives may be added. Acids used for metal extraction may also be removed, in whole or in part, if necessary. The objective is to obtain a metal solution whose composition matches the desired composition of the impregnation solution used for the synthesis of a new catalyst.

The adjustment of the metal ratios is achieved either by adding a makeup solution containing one or more of the metals in question, or by directly dissolving one or more metal precursors in the extracted metal/metal solution, the latter being preferred. The molar ratio of Group VIII metal to Group VIB metal in the metal solution after this adjustment step is generally between 0.1 and 0.8, preferably between 0.15 and 0.6.

Phosphorus and/or an organic compound can also be added to the impregnation solution.

The metallic precursors of the group VIII metal, in particular based on molybdenum or tungsten, the metallic precursors of the group VIB metal, in particular based on cobalt and nickel, the phosphorus precursors and the organic compound are those indicated for step i). They are introduced in the ratios indicated for step i). The organic compound may be the same as or different from the organic acid introduced in step b) of extraction.

The extracted metal(s) solution may contain an excess of acid relative to the desired impregnation solution. The acid-to-metal ratios can be adjusted in two ways. The first is to add a concentrated solution of metal precursors, or to dissolve these metal precursors directly to achieve the desired ratios. In this case, the final catalyst will consist of a mixture of recycled and virgin metals.

If the excess acid is too large to use the first method (i.e., the amount of recycled metals incorporated into the final catalyst is not significant, for example, less than 5% of the total amount of metals), the second method consists of removing all or part of the excess acid from the metal solution. In this case, the acid can be recycled to the leaching process according to the invention. The concentration of excess acid can be reduced, for example, by evaporation, liquid-liquid extraction, adsorption, or membrane separation.

The extracted metal(s) solution, possibly previously subjected to one or more of the treatments described below, can be used to prepare a new catalyst. This is achieved by contacting an oxide support, or a catalyst already containing one or more metals, with the extracted metal(s) solution. This contact can be made by any known method, such as ion exchange, dry impregnation, excess impregnation, vapor deposition, etc. The contact can be carried out in one step or in several successive steps. In a preferred method, the support is brought into contact with the metal solution by excess impregnation or by dry impregnation. It is generally carried out under the conditions described in step i).

Preferably, an impregnation of a support is carried out with an impregnation solution derived from said solution of extracted group VIB and/or VIII metal(s), to obtain an impregnated substrate, said extracted metal(s) remaining in liquid phase from extraction by an extraction solution comprising an alcohol until impregnation.

According to the present invention, it is understood that the impregnation solution is "derived" from the extraction solution as meaning that there is no intermediate treatment where the extracted metal(s) would be in solid phase, nor any liquid/liquid extraction treatment of the latter.

The term "support" (which will be impregnated with the impregnation solution derived from the extracted metal(s) solution) refers to a "new" oxide support, but also to a support that has already been impregnated with another impregnation solution – referred to as a pre-impregnated support – or to a support that is actually a catalyst (a support containing metals) but which contains an insufficient quantity of metals, such as a used or regenerated catalyst. The support can also be the leaching residue obtained in step b).

The oxide support that will be impregnated with the impregnation solution from the extracted metal(s) solution can be of the same nature as the support of the source catalyst, a description of which has already been given above.

After the step of contacting the oxide support or a catalyst already containing one or more metals with the solution of extracted metal(s), preferably by impregnation, a maturation step is advantageously carried out, followed by a drying step under the conditions described in step i). Optionally, the drying can be followed by a calcination step under the conditions described in step i).

When the catalyst includes an organic compound, calcination is preferably not carried out.

The quantity of recycled metals contained in the new catalyst is between 1% and 100% wt of the metals contained in the new catalyst, preferably between 10% and 100% wt, preferably between 20% and 100% wt, and even more preferably between 50% and 100% wt of the weight of the new catalyst.

It should be noted that the new catalyst may have a different formulation than the source catalyst used to recover the metals, and different quantities and ratios of metals: thus, a source catalyst with a high metal content can, according to the invention, be used to produce a catalyst with a lower metal content (or vice versa). This makes it possible, where appropriate, to avoid a concentration step of the solution after extraction or at least to reduce its intensity/duration.

It should also be noted that the new catalyst can be post-additized, meaning that an additional impregnation step of one or more organic additives can be carried out, the function of which is to increase the catalytic activity compared to non-additized catalysts, before the final optional sulfidation, it being understood that, preferably, no calcination step is carried out after its introduction.

Hydrotreating and/or hydrocracking process

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

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

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

Fossil fuel feedstock typically consists of a fraction derived from coal or hydrocarbons produced from natural gas, possibly in mixtures. It can also include heavy petroleum or synthetic fractions, such as kerosene, diesel, or distillates obtained through atmospheric and vacuum distillation to produce usable kerosene, diesel, or vacuum distillate. This usable product is then either stored in a pool receiving similar products or sent to a downstream unit, such as a catalytic cracking unit, where the feedstock is cracked to produce shorter-chain hydrocarbons. Hydrotreating is often a preliminary step in the hydroconversion/hydrocracking process of treating a feedstock.

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

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

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

The feedstock from biomass conversion can also advantageously be chosen from feedstocks from the paper industry.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The hydrotreating process consists of bringing the hydrocarbon fraction into contact with the catalyst and hydrogen under the following conditions: at a temperature between 200 and 400°C, preferably between 230 and 330°C, at a total pressure between 1 and 3 MPa, preferably between 1.5 and 2.5 MPa, at a Volumetric Rate of Flow (VRF), defined as the volumetric flow rate of feed relative to the volume of catalyst, between 1 and 10 h^-1, preferably between 2 and 6 hours^-1and at a hydrogen/gasoline charge volume ratio between 100 and 600 Nl/l, preferably between 200 and 400 Nl/l.

The hydrotreatment process for gasoline can be carried out in one or more reactors in series, either of the fixed bed or bubbling bed type. If the process is implemented using at least two reactors in series, it is possible to provide a device for removing _H₂S from the effluent of the first hydrodesulfurization reactor before treating said effluent in the second hydrodesulfurization reactor.

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

It is also possible to use fines from a source catalyst which does not have the same function as the catalyst prepared by the process according to the invention, as long as the fines and the catalyst produced have at least one metal in common (hydrotreating catalyst, hydrocracking catalyst, Fischer-Tropsch catalyst).

Examples Example 1: Obtaining the leaching residue A

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

The regenerated catalyst contains molybdenum, phosphorus and cobalt. The composition of the catalyst is expressed in the form of oxides and referred to the mass of dry catalyst: 21.6 wt% MoO ₃ (14.4 wt% molybdenum), 3.7 wt% CoO (2.9 wt% cobalt, i.e. a molar ratio Co/Mo of 0.33) and 3.2 wt% P ₂ O ₅ (1.4 wt% phosphorus, i.e. a molar ratio P/Mo of 0.3).

A step to extract molybdenum and cobalt from this regenerated catalyst is carried out on a laboratory scale: 30 g of this regenerated catalyst (referred to as the source catalyst), previously ground to a D90 size between 100 and 300 micrometers, and 75 mL of extraction solution are introduced into a flask. The extraction solution is an aqueous solution containing 0.05 mol/L of citric acid. The mixture is stirred at room temperature at 200 rpm using a magnetic stir bar for 6 hours. The mixture is then filtered through sintered glass with a porosity of 5 to recover a polymetallic solution on one hand and a leaching residue on the other, which is washed three times with distilled water. Leaching residue A is obtained _. Analysis of leaching residue A shows that it contains 7.9 wt% of _MoO3 , 1.2 wt% of CoO and 2.9% of _P2O5 and that its loss on ignition (LOI) is 55%.

Example 2: Preparation of catalyst B according to the invention

To prepare catalyst B, the fines from leaching residue A are introduced, along with 5 wt% Methocel ^™, into a closed tank of a Brabender-type cam-arm mixer. No peptizing agent or water is added to facilitate paste formation, in addition to the Methocel ^™ . The paste is mixed for 30 minutes and then extruded using a piston extruder through a 1.8 mm diameter die. The resulting extrudates are dried (16 hours at 120°C in an air-ventilated oven). The characteristics of the resulting catalyst B are given in Table 1.

Example 3: Preparation of catalyst C according to the invention

To prepare catalyst C, the fines from leaching residue A are first dried to achieve a loss on ignition (LOI) of 47%, then mixed with 3 wt% of Methocel ^™ into a closed tank of a Brabender-type cam-arm mixer. No peptizing agent or water is added to facilitate pulping, in addition to the Methocel ^™ . The resulting extrudates are dried (16 hours at 80°C in an air-ventilated oven). The characteristics of the resulting catalyst C are given in Table 1.

Example 4: Preparation of catalyst D according to the invention

To prepare catalyst D, 23 g of fines from leaching residue A are first dried to achieve a loss on ignition (LOI) of 40%. They are then mixed with 4.7 g of boehmite and 2 wt% Methocel ^™ into a closed tank of a Brabender cam-arm mixer. A peptizing agent, nitric acid ( _HNO₃ ), is added to reach an acid content of 1%. Water is also gradually added to achieve a loss on ignition (LOI) of 50%, the value being adjusted according to the formulation to obtain a homogeneous and cohesive paste. The paste is mixed for 20 min, then an ammonia solution is gradually added to neutralize 30% of the acidity and achieve a LOI of 52%. The paste is then kneaded for another 10 minutes and then extruded using a piston extruder through a 1.8 mm diameter die. The resulting extrudates are dried (16 hours at 80°C in a ventilated oven under air) and then calcined at 500°C for 4 hours under dry air. The characteristics of the resulting catalyst D are given in Table 1.

Table 1 below summarizes the characteristics of the synthesized catalysts B to D.

Catalyst B Catalyst C Catalyst D Total pore volume (mL/g) 0.55 0.48 0.55 Mesoporous volume (mL/g) 0.35 0.4 0.5 Macroporous volume (mL/g) 0.2 0.08 0.05 S _BET (m ² /g) 230 200 260 EGG (daN/mm) 0.4 1.1 0.9

The process according to the invention makes it possible to obtain catalysts exhibiting mechanical resistance (measured by EGG) and macroporous volume compatible with their uses in a hydrotreating and/or hydrocracking process.

Claims (17)

A process for preparing a catalyst comprising at least one metal from group VIB and/or at least one metal from group VIII, and an oxide support, said process comprising at least the following steps:
a) Fine particles having a D90 size less than or equal to 500 micrometers are made available from a source catalyst comprising at least one metal from group VIB and/or at least one metal from group VIII, and an oxide support, then
b) an extraction of part of the group VIB metal and/or part of the group VIII metal from said fines of the source catalyst is carried out by an extraction solution comprising at least one acid to obtain a solution of the extracted metal(s) and a leaching residue, then
(c) a mixture is prepared comprising said leaching residue obtained in step (b) and an extrusion aid, and optionally an inorganic oxide binder,
d) the mixture obtained in step c) is kneaded
e) Optionally, a neutralizing agent chosen from an inorganic base and an organic base is added to the mixture obtained in step d),
f) The mixture obtained in step d) or step e) is shaped by extrusion to obtain a solid,
g) the solid obtained in step f) is dried at a temperature below 200°C. A process according to claim 1, comprising a step h) in which the dried solid obtained in step g) is calcined at a temperature between 200°C and 600°C. A method according to any one of the preceding claims, wherein the D90 size of the fines made available in step a) is less than 300 micrometers. A process according to any one of the preceding claims, wherein the fines made available in step a) have a group VIB metal content of between 5 and 40% by weight of group VIB metal oxide and a group VIII metal content of between 1 and 50% by weight of group VIII metal oxide relative to the weight of the fines. A process according to any one of the preceding claims, wherein the oxide support of the fines made available in step a) is selected from alumina, silica, silica-alumina, titanium oxide or magnesium oxide used alone or in a mixture with alumina or silica-alumina. A process according to any one of the preceding claims, wherein the acid in the extraction solution of step b) is an inorganic acid selected from phosphoric acid, nitric acid, boric acid or sulfuric acid. A process according to claims 1 to 5, wherein the acid in the extraction solution of step b) is an organic acid selected from formic acid, acetic acid, oxalic acid, malonic acid, glutaric acid, glycolic acid, lactic acid, tartronic acid, citric acid, tartaric acid, pyruvic acid, γ-ketovaleric acid, succinic acid, acetoacetic acid, gluconic acid, ascorbic acid, phthalic acid, salicylic acid, maleic acid, malic acid, fumaric acid, acrylic acid, thioglycolic acid, 2-hydroxy-4-methylthiobutanoic acid, glutamic acid, N-acetylglutamic acid, alanine, glycine, cysteine, histidine, aspartic acid, N-acetylaspartic acid, 4-aminobutanoic acid, 1,2-cyclohexanediaminetetraacetic acid, ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), iminodiacetic acid (IDA), N-(2-hydroxyethyl)ethylenediamine-N,N′,N′-triacetic acid (HEDTA), diethylenetriaminepentaacetic acid (DTPA), bicine, tricine, 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP or etidronic acid), nitrilotris(methylenephosphonic) acid, diethylenetriaminepentakis(methylenephosphonic) acid, 4-sulfophthalic acid, 3-(N-morpholino)-2-hydroxy-1-propanesulfonic acid (MOPSO), 2-(4-Pyridinyl)ethanesulfonic acid, phenol-4-sulfonic acid, thiodiacetic acid and diglycolic acid. A process according to any one of the preceding claims, wherein the concentration of each acid in the extraction solution of step b) is between 0.03 and 2 mol/L. A process according to any one of the preceding claims, wherein the extraction solution of step b) further comprises at least one organic compound having complexing properties. A process according to any one of the preceding claims, wherein a reduction of the loss on ignition of the leaching residue obtained in step b) is effected by drying and/or by mixing the leaching residue with dry fines of the source catalyst and/or an inorganic oxide binder. A process according to any one of the preceding claims, wherein the content of the extrusion aid in step c) is between 0.1 and 10% by weight relative to the weight of the dry leaching residue and the dry inorganic oxide binder when present. A process according to any one of the preceding claims, wherein the extrusion aid agent is selected from methylcellulose, cellulose, carboxy-methyl-cellulose and carboxy-ethyl-cellulose. A process according to any one of the preceding claims, wherein said inorganic oxide binder of step c) is present and is selected from the group formed by the following oxides or their hydrated forms: alumina, silica, silica-alumina, clays, titanium oxide, boron oxide and zirconia, taken alone or in mixture. A process according to any one of the preceding claims, wherein said inorganic oxide binder is introduced into the mixture in step c) so that the inorganic oxide binder content is less than 95% by weight relative to the weight of the dry catalyst obtained at the end of step g) of drying. A process according to any one of the preceding claims, when step d) is carried out, said mixture obtained in step c) is added a neutralizing agent selected from an inorganic base and an organic base, said inorganic base being selected from sodium hydroxide, potassium hydroxide, and ammonia, alone or in mixture, and said organic base being selected from amines and quaternary ammonium compounds alone or in mixture. A process according to any one of the preceding claims, wherein it comprises a step i) in which at least one metal from group VIB and/or at least one metal from group VIII, and optionally phosphorus and/or at least one organic compound comprising oxygen and/or nitrogen and/or sulfur, is brought into contact with the catalyst obtained after step g) of drying or after step h) of calcination, the contacting being followed by a drying step at a temperature below 200°C, and optionally by a subsequent calcination step. A process according to any one of the preceding claims, wherein the solution of metal(s) of group VIB and/or VIII extracted from step b) is used as an impregnation solution for a support, said extracted metal(s) remaining in liquid phase from extraction until impregnation.