Method for the preparation of a catalyst by selective extraction from an arsenic- and vanadium-contaminated catalyst

Abstract

A method for producing a catalyst comprising a group VIB metal and / or a group VIII metal and an oxide support, characterized in that the method comprises recycling the group VIB and / or group VIII metals from a source catalyst containing a metal shared with the catalyst to be produced, said source catalyst being contaminated with coke, vanadium and arsenic, the method comprising: - extracting the vanadium with an extraction solution comprising sulfuric acid, then - a regeneration, then - extracting the group VIB and / or group VIII metal or metals with an extraction solution comprising an organic compound having complexing properties, then - impregnating the support with an impregnation solution derived from said solution of extracted group VIII and / or group VIB metal / metals, the extracted metal(s) remaining in the liquid phase from the extraction with sulfuric acid until the impregnation.

Description

[0001] PROCESS FOR PREPARING A CATALYST BY SELECTIVE EXTRACTION FROM A CATALYST CONTAMINATED WITH ARSENIC AND VANADIUM

[0002] Technical field

[0003] The present invention relates to the recycling of catalyst metals, particularly from hydrocarbon hydrotreatment or hydroconversion units, to remanufacture catalysts. More particularly, the present invention relates to a method for preparing a catalyst involving a series of steps for extracting a contaminated catalyst, making it possible to obtain an extraction solution concentrated in the desired metals and containing only a few contaminants. The extraction solution is then used as an impregnation solution to prepare a catalyst. The catalyst thus obtained is intended, in particular, to be used in hydrocarbon hydrotreatment or hydroconversion units.

[0004] Prior art

[0005] Most of the technological innovations needed for the energy transition (electric vehicles, wind power, fuel cells, batteries, etc.) require the massive use of metals. To meet this demand while ensuring sustainable development, metal recycling is becoming a major challenge for the coming century.

[0006] In particular, spent catalysts from hydrocarbon hydrotreatment or hydroconversion units contain metals of interest, namely at least one metal from group VI B 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 essentially reused for the manufacture of special alloys, requiring complex purification operations, in particular to rid the recovered metals of compounds considered to be contaminants, such as arsenic, or problematic in view of the intended applications, such as phosphorus, the presence of which disrupts, for example, the properties of chrome steel alloys.

[0007] During operation in a hydrotreatment or hydroconversion process, a catalyst becomes deactivated by the accumulation of coke and / or sulfur compounds and / or other contaminants on the catalyst surface. The contaminants originate from the feedstock. The most common contaminants are metals such as nickel, vanadium, iron, titanium, but also silicon, calcium, sodium, potassium, chlorine, and arsenic. While poisoning by coke, for example, is reversible, poisoning by metals can lead to structural changes and irreversible deactivation of the catalyst. The most common metals in crude oils and heavy feedstocks are vanadium and nickel. These metals are generally less present in lighter feedstocks. Similarly, several studies have shown the adverse effect of a small amount of arsenic on the service life of hydrotreatment and / or hydroconversion catalysts.Organic arsenic compounds react rapidly under hydrotreatment conditions to be decomposed and adsorbed onto the catalyst surface. The most problematic contaminants in a hydrotreatment and / or hydroconversion catalyst are therefore often arsenic, but also vanadium.

[0008] Processes for extracting contaminants from used catalysts have been developed. These processes aim to extract only the contaminants, in particular vanadium and nickel, without extracting the active phase consisting of the metals of group VIII and / or VI B, with the aim of restoring the original catalytic activity. The objective is therefore often to be able to recycle the catalyst freed from these contaminants. These processes generally involve extracting the contaminants using a solution containing an inorganic acid such as sulfuric acid. Thus, document US5906953 describes a process for extracting the remains of the charge contained in the catalyst by deoiling (heavy oil), followed by washing with water, extraction of the vanadium and nickel using a solution containing sulfuric acid, another washing with water and regeneration to remove the coke.US4595666 describes a similar process with deoiling, followed by water washing, extraction of iron, titanium, calcium, sodium, vanadium and nickel by a solution containing sulfuric acid, optionally in the presence of an ammonium ion, another water wash and regeneration to remove coke.

[0009] Processes for recovering group VIII and / or VI B metals from the active phase of catalysts have also been developed in order to recycle them for the manufacture of new catalysts.

[0010] For example, patent application US 2007 / 0167321 proposes recovering molybdenum from used catalysts to make new catalysts. To do this, according to this process, the used catalyst is dispersed in a basic solution, a contaminant / compound contained in the used catalyst that is to be eliminated (arsenic, phosphorus) is removed from the solution by precipitating it, and then the solution is filtered. The molybdenum is then precipitated by changing the pH of the solution to an acidic pH. The molybdenum precipitate is filtered so that it can be reused by dispersing it in an impregnation solution also containing precursors of other metals, such as precursors of cesium, antimony or vanadium, and other components necessary to form the new catalyst by impregnating a support.

[0011] Patent application FR3117381 proposes the production of a recycled catalyst for hydrotreatment or hydroconversion of hydrocarbons. The group VIII metal and the group VI B metal are extracted by an aqueous solution containing at least one organic compound having complexing properties, and possibly also acidic properties. The resulting solution is then directly used for impregnation on an oxide support to produce a recycled catalyst, i.e. the extracted metals remain in the liquid phase throughout this process. Unlike previous techniques, this process does not seek to recover the metal in solid and monometallic form, thus avoiding a number of precipitation / filtration operations. The process is therefore easy to implement on an industrial scale.

[0012] When extracting metals from a contaminated catalyst to use the solution obtained directly for impregnation on a support in order to produce a catalyst as described in document FR3117381, it would thus be advantageous to obtain an extraction solution containing on the one hand a high concentration of the metals of interest, in particular metals from groups VIII and / or VI B, and on the other hand as low a concentration as possible of contaminants. The present invention thus aims at a selective extraction of the metals from group VIII and / or group VI B with respect to the contaminants, and in particular with respect to vanadium and arsenic. However, when extracting the desired metals, the extraction of at least part of one or more contaminants is often unavoidable. The treatment of contaminated catalysts is not trivial because the extraction of contaminants depends on their nature and content.Contaminants will not all be distributed in the same way between the solution and the leached catalyst depending on their nature and the leaching agent.

[0013] The present invention presents an improvement of the process described in document FR3117381 making it possible to obtain an extraction solution concentrated in desired metals and containing only a few contaminants by a specific and clever sequence which, depending on the nature of the contaminant, allows either to extract contaminants without extracting the active phase, or to leave contaminants in the leached catalyst. The extraction solution is then used as an impregnation solution as described in document FR3117381. Summary of the invention

[0014] The invention relates to a process for producing a catalyst comprising at least one metal from group VIB and / or at least one metal from group VIII, optionally phosphorus and / or sulfur, and an oxide support(s), characterized in that said process comprises recycling at least a portion of the metal(s) from group VIB and / or group VIII from a source catalyst comprising at least one metal from group VIB and / or at least one metal from group VIII common with the catalyst to be produced, said source catalyst being contaminated with at least coke, vanadium and arsenic, the process comprising:

[0015] - an extraction of at least a portion of the vanadium from said source catalyst by an extraction solution comprising at least sulfuric acid, to obtain a source catalyst depleted in vanadium, then

[0016] - a regeneration of said vanadium-depleted source catalyst to obtain a regenerated source catalyst, then

[0017] - an extraction of the group VIB metal and / or the group VIII metal from said regenerated source catalyst by an extraction solution comprising at least one organic compound having complexing properties, to obtain a solution of extracted group VIB and / or VIII metal(s), then

[0018] - impregnation of the support 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 at least sulfuric acid until impregnation.

[0019] The process according to the invention makes it possible to ensure a high extraction rate of group VIII and / or VIB metals while limiting the presence of contaminants, in particular vanadium and arsenic in an extraction solution which is subsequently used as an impregnation solution.

[0020] Indeed, sulfuric acid extraction allows selective extraction of at least part of the vanadium without extracting the active phase thanks to the presence of coke in the source catalyst. The vanadium-depleted source catalyst is then subjected to regeneration which eliminates the coke and makes the active phase accessible to extraction by an extraction solution comprising at least one organic compound with complexing properties. The organic compound allows extraction of the active phase while limiting the extraction of the arsenic which remains on the leached catalyst. This is thus obtained by a clever sequence of operations, an extraction solution concentrated in the desired metals containing only a few contaminants which is subsequently used as an impregnation solution for the manufacture of a new catalyst.

[0021] Furthermore, the invention provides a process, where the metal from the source catalyst is dissolved, and remains in solution until it is reused as an impregnation solution top-up to produce the fresh / new catalyst. Unlike prior art, the invention does not seek to recover the metal from the source catalyst in solid, monometallic form, thus avoiding a number of precipitation / filtration type operations.

[0022] According to one variant, the source catalyst comprises coke in a content of between 2 and 20% by weight, vanadium in a content of between 1 and 50,000 ppm by weight and arsenic in a content of between 1 and 25,000 ppm by weight, relative to the total weight of the source catalyst, said contents being expressed as an element.

[0023] Alternatively, the concentration of sulfuric acid is between 0.5 and 3 mol / L.

[0024] According to one variant, the extraction solution comprising at least sulfuric acid also comprises an alcohol.

[0025] According to one variant, the alcohol in the extraction solution comprising at least sulfuric acid is chosen from at least one of the following compounds: methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, tert-butanol,

[0026] 1.2-ethanediol, 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol,

[0027] 2.3-butanediol, 1,5-pentanediol and 1,6-hexanediol.

[0028] According to a variant, in the extraction step with an extraction solution comprising at least sulfuric acid, the extraction rate of vanadium is greater than 10% by weight, the extraction rate of the group VIII metal is less than 50% by weight, the extraction rate of the group VIB metal is less than 20% by weight, the extraction rate corresponding to the mass of vanadium and metal / metals extracted in the extraction solution relative to the mass of vanadium and metal / metals initially present on the source catalyst.

[0029] According to one variant, the regeneration step is carried out at a temperature between 320°C and 550°C under a flow of gas containing oxygen.

[0030] According to one variant, the organic compound of the extraction solution comprising at least one organic compound having complexing properties is 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 of between 200 and 1500 g / mol), propylene glycol, glycerol, 2-butoxyethanol, 2-(2-butoxyethoxy)ethanol, 2-(2-methoxyethoxy)ethanol, triethylene glycol dimethyl ether, crown ether, acetophenone, 2,4-pentanedione, pentanone, glucose,fructose, sucrose, sorbitol, xylitol, mannitol, y-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, 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.,

[0031] According to one variant, the organic compound in the extraction step with an extraction solution comprising at least one organic compound has complexing and acidic properties.

[0032] According to one variant, the organic compound is 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 of the extraction solution comprising at least one organic compound having complexing properties is chosen from formic acid, acetic acid, oxalic acid, citric acid, γ-ketovaleric acid, fructose, ethylene glycol, diethylene glycol and triethylene glycol.

[0033] According to one variant, the concentration of each organic compound in the extraction solution comprising at least one organic compound having complexing properties is between 0.03 and 2 mol / L.

[0034] According to a variant, in the extraction step with an action extraction solution comprising at least one organic compound having complexing properties, the extraction rate of the metal from group VIII or group VI B is respectively greater than 50% by weight and the extraction rate of arsenic is less than 30% by weight, the extraction rate corresponding to the mass of the extracted metal / metals and of the extracted arsenic in the extraction solution relative to the mass of the metal / metals present and of the arsenic initially present on the source catalyst.

[0035] According to one variant, the source catalyst is subjected to at least one pretreatment step before the sulfuric acid extraction step chosen from deoiling, grinding or washing with water.

[0036] According to one variant, the solution of extracted metal(s) is subjected to at least one treatment step before impregnation of the support, said treatment step being chosen from a concentration, a dilution and / or a modification of the composition of the solution by addition or elimination, total or partial, of at least one compound from said solution.

[0037] According to a variant, the impregnation of the support with an impregnation solution is carried out from the solution of extracted metal(s) and an addition of at least one of the metals from group VIII / VIB, and possibly phosphorus and / or organic additive(s).

[0038] According to one variant, at least part of the impregnation solution is reused after impregnation of the support as a supplement to the extraction solution comprising at least one organic compound having complexing properties.

[0039] According to one variant, the support on which the impregnation is carried out with the impregnation solution resulting from the extracted metal / metals solution is pre-impregnated or post-impregnated with an impregnation solution or is a metal-depleted catalyst. According to one variant, said impregnated substrate obtained after the impregnation is subjected to a drying step, optionally to a calcination step and optionally to a sulfurization step.

[0040] Definitions

[0041] For the purposes of the present invention, the various embodiments presented can be used alone or in combination with each other, without limitation of combination.

[0042] For the purposes of the present invention, the different parameter ranges for a given step such as pressure ranges and temperature ranges may be used alone or in combination. For example, for the purposes of the present invention, a preferred range of pressure values ​​may be combined with a preferred range of temperature values.

[0043] In the remainder of the text, the expressions "between ... and ..." and "between .... and ..." are equivalent and mean that the limit values ​​of the interval are included in the range of values ​​described. If this were not the case and the limit values ​​were not included in the range described, such precision will be provided by the present invention.

[0044] In this description, the term "include" is synonymous with (means the same as) "include" and "contain", and is inclusive or open and does not exclude other elements not mentioned. It is understood that the term "include" includes the exclusive and closed term "consist".

[0045] 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 thereof.

[0046] In this description, the term "extraction" is synonymous with the term "leaching", unless otherwise indicated. The term "leaching" or "extraction" in this description means extracting one or more metals from a solid (source catalyst) by dissolving it in a liquid (leaching solution or extraction solution).

[0047] In this description, the term "extracted metal(s)" refers to the desired metals, i.e., metals of group VIII and / or VI B. 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 desired to be extracted. Contaminants include nickel 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.

[0048] In the sense of the present invention, it is necessary to distinguish the nickel possibly contained in the active phase of the source catalyst (and which one wishes to extract) from the contaminating nickel brought by the charge. Unlike the nickel of the active phase which is distributed homogeneously throughout the catalyst, the contaminating nickel is generally more concentrated at the periphery of the catalyst grain (beads, extrudates, etc.), and forms more or less well distributed clusters. Its presence in decoration of the M0S2 is also very limited.

[0049] According to the present invention, the pressures are absolute pressures, also noted abs., and are given in absolute MPa (or MPa abs.), unless otherwise indicated.

[0050] In the following text, the groups of chemical elements are given according to the CAS classification (CRC Handbook of Chemistry and Physics, publisher CRC press, editor-in-chief DR Lide, 81st edition, 2000-2001). For example, group VIII (or VI I IB) according to the CAS classification corresponds to the metals in columns 8, 9 and 10 according to the new IIIPAC classification, and group VIB to the metals in column 6.

[0051] Elemental analyses, typically by inductively coupled plasma spectrometry (ICP) or by X-ray fluorescence spectrometry, more commonly known as X-ray fluorescence (FX), make it possible to quantify the content of the different elements in the catalyst pretreated at 550°C in air and in the extraction solution.

[0052] Detailed description

[0053] The present invention relates to the recycling of catalyst metals originating in particular from hydrocarbon hydrotreatment or hydroconversion units.

[0054] Hydrotreatment refers to all the purification processes that eliminate, by the action of hydrogen, the various impurities contained in hydrocarbon feedstocks. Hydrotreatment processes eliminate, by the action of hydrogen, impurities present in feedstocks such as nitrogen (hydrodenitrogenation), sulfur (hydrodesulfurization), oxygen (hydrodeoxygenation), and compounds containing metals that can poison the catalyst and cause operational problems downstream (hydrodemetallation). Hydrotreatment can thus make it possible to bring the hydrocarbon to the required specifications (sulfur content, aromatics, etc.) for a given application (car fuel, gasoline or diesel, domestic heating oil, etc.). Automotive standards, in particular, have imposed a very significant reduction in sulfur in diesel and gasoline fuels, hydrotreatment thus making it possible to bring these products to the required specifications.

[0055] Hydrotreatment will therefore improve the quality of hydrocarbons by reducing the content of certain compounds, elements considered as impurities, but it can also reduce the content of aromatic hydrocarbons, by hydrogenation, and thus improve the cetane index of hydrocarbons. During hydrotreatment processes, fuel gas and light cuts such as LPG (acronym for Liquefied Petroleum Gas) and naphtha can also be produced in small quantities.

[0056] It should be remembered that hydrocracking (also known as hydroconversion) of heavy hydrocarbon fractions is a key refining process that allows the production, from excess and low-value heavy feedstocks, of lighter fractions such as gasoline, jet fuels and light diesel fuels that the refiner is looking for to adapt its production to demand. Some hydrocracking processes also allow the production of a highly purified residue to be obtained, which can be used as an excellent base for oils.

[0057] The hydrocarbon feedstock targeted by hydrotreatment and / or hydroconversion can be of different types. The feedstock may be of fossil origin or derived from the conversion of biomass or waste, taken alone or in a mixture. The feedstocks that are treated, and in particular those mentioned below, generally contain heteroatoms such as sulfur, oxygen and nitrogen and may contain other contaminants such as iron, titanium, silicon, calcium, sodium, potassium, chlorine and arsenic, but also, in particular for heavier feedstocks, nickel and vanadium.

[0058] The fossil feedstock may be a cut from coal or hydrocarbons produced from natural gas, possibly in mixtures. It may also be heavy petroleum or synthetic cuts, for example kerosene, gas oil or distillates from atmospheric and vacuum distillation to produce kerosene, gas oil or vacuum distillate that can be recovered, either in the storage unit receiving products of the same type ("pool" in English), or to a downstream unit such as a catalytic cracking unit, where the feedstocks are "cracked" to produce shorter-chain hydrocarbons. It is common for the hydrotreatment process to be a preliminary step in the treatment of a feedstock by a hydroconversion / hydrocracking type process.The feedstocks of fossil origin used in a hydrotreatment process, in more detail, are for example gasolines, diesel oils, vacuum diesel oils, atmospheric residues, vacuum residues, atmospheric distillates, vacuum distillates, heavy fuels, oils, waxes and paraffins, used oils, residues or deasphalted crudes, feedstocks from thermal or catalytic conversion processes, taken alone or in a mixture.

[0059] The feedstock resulting from the conversion of biomass may advantageously be chosen from vegetable oils, algae or algal oils, fish oils, used edible oils, and fats of vegetable or animal origin; or mixtures of such feedstocks. Said vegetable oils may advantageously be crude or refined, totally or partially, and derived from plants chosen from rapeseed, sunflower, soybean, palm, olive, coconut, copra, castor oil, 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 industries.Frying oils, various animal oils such as fish oils, tallow, lard can also be used. The feedstock resulting from biomass conversion can also advantageously be chosen from fatty acid methyl esters of vegetable and / or animal origin or fatty acid methyl esters from used edible vegetable oils.

[0060] The feedstock from biomass conversion may also be selected from feedstocks from thermal or catalytic biomass conversion processes, such as oils that are produced from biomass, particularly lignocellulosic biomass, with various liquefaction methods, such as hydrothermal liquefaction or pyrolysis. The term "biomass" refers to material derived from recently living organisms, which includes plants, animals and their by-products. The term "lignocellulosic biomass" refers to biomass derived from plants or their by-products. Lignocellulosic biomass is composed of carbohydrate polymers (cellulose, hemicellulose) and an aromatic polymer (lignin).

[0061] The feedstock from biomass conversion can also advantageously be chosen from feedstocks from the paper industry.

[0062] The feedstock from waste conversion can be pyrolysis oil from plastics, tires, or solid recovered fuels (SRF). These oils are obtained by thermal or catalytic pyrolysis treatment or can be prepared by hydropyrolysis (pyrolysis in the presence of a catalyst and hydrogen). Conventional hydrotreatment catalysts generally comprise an oxide support and an active phase based on metals from groups VI, B, and VIII in their oxide forms, as well as phosphorus. The preparation of these catalysts generally includes a step of impregnation of the metals and phosphorus onto the support, followed by drying and calcination to obtain the active phase in their oxide forms. Before their use in a hydrotreatment and / or hydroconversion reaction, these catalysts are generally also subjected to sulfurization.

[0063] The addition of an organic additive to hydrotreatment catalysts to improve their activity is also known, particularly for catalysts that have been prepared by impregnation followed by drying without subsequent calcination. These catalysts are often referred to as "additive-dried catalysts".

[0064] The catalysts used in hydrocracking are bifunctional, i.e. combining an acid function with a hydrogenating function. The acid function is provided by supports with large surface areas (150 to 800 m 2 .g' 1generally) with significant acidity, such as halogenated aluminas (chlorinated or fluorinated in particular), combinations of boron and aluminum oxides, amorphous silica-aluminas and zeolites. The hydrogenating function is provided either by one or more metals from group VIII, or by a combination of at least one metal from group VIB and at least one metal from group VIII, implemented in the presence of sulfur. The balance between the two acid and hydrogenating functions governs the activity and selectivity of the catalyst

[0065] During operation in a hydrotreatment or hydroconversion process, the catalyst is deactivated by the accumulation on the surface of the catalyst of coke and / or sulfur compounds and / or other contaminants such as nickel, vanadium, iron, titanium, but also silicon, calcium, sodium, potassium, chlorine and arsenic. Beyond a certain period, its replacement is therefore necessary.

[0066] To combat these drawbacks, the regeneration (also called soft calcination) of hydrotreatment / hydroconversion catalysts is an economically and ecologically interesting process, as it allows these catalysts to be reused in industrial units rather than being landfilled or recycled (metal recovery). Regeneration consists of a heat treatment, generally between 350°C and 550°C, in the presence of pure or diluted oxygen, with the aim of eliminating at least part of the coke present on the spent catalyst by combustion. This regeneration allows the so-called "regenerated" catalyst to recover from the hydrotreatment / hydroconversion activity. However, regenerated catalysts are generally less active than the starting catalysts, also called "fresh". As a result, their cycle time in the hydrotreatment / hydroconversion unit is reduced compared to that of a fresh catalyst.Eventually, it can be reused in less demanding applications.

[0067] In order to compensate for the lack of hydrotreatment / hydroconversion activity of the regenerated catalyst, it is possible to apply an additional treatment called "rejuvenation". The rejuvenation process consists of re-impregnating the already regenerated catalyst with a solution containing organic or inorganic additives and / or metal precursors. These rejuvenation processes are well known, particularly in the field of middle distillates. Although more efficient than simple regeneration, rejuvenation of catalysts nevertheless leads in most cases to a catalyst with a lower activity than the fresh catalyst.Finally, some used catalysts cannot be reused via regeneration or rejuvenation, either because their integrity is impaired (too low size or mechanical strength), or because they contain too large a quantity of contaminants, making the performance of the regenerated or rejuvenated product insufficient.

[0068] Although the present invention aims at the recycling of catalyst metals originating in particular from hydrocarbon hydrotreatment or hydroconversion units, it is understood that the process according to the invention applies to 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, hydrotreatment catalysts for residues (for example carried out in an ebullated bed) or Fischer-Tropsch catalysts.

[0069] The source catalyst

[0070] According to the present invention, the term "source" catalyst means the catalyst from which the metals are to be extracted. The "source" catalyst is generally an at least partially spent catalyst, i.e. one that has already been used in production, in particular in hydrotreatment or hydroconversion installations, for example of the hydrocracking type. This term also includes an at least partially spent capture mass.

[0071] The source catalyst comprises at least one metal from group VIII and / or at least one metal from group VIB, an oxide support, and optionally phosphorus. It also comprises as contaminants at least coke, vanadium and arsenic. It may also, in a non-limiting manner, comprise sulfur as well as other contaminants as described below. The oxide support of said source catalyst is usually a porous solid chosen from the group consisting of: aluminas, silica, silica-aluminas or titanium or magnesium oxides used alone or in a mixture with alumina or silica-alumina. Preferably, the oxide support is essentially constituted by at least one transition alumina, that is to say it comprises at least 51% by weight, preferably at least 60% by weight, very preferably at least 80% by weight, or even at least 90% by weight of transition alumina.It preferably consists solely of a transition alumina. Preferably, the oxide support of said catalyst is a gamma phase alumina.

[0072] In another preferred case, the oxide present in the support of said source catalyst is a silica-alumina containing at least 50% by weight of alumina relative to the total weight of the composite support. The silica content in the support is at most 50% by weight relative to the total weight of the support, most often less than or equal to 45% by weight, preferably less than or equal to 40% by weight.

[0073] According to a particularly preferred variant, the support of the source catalyst consists of alumina, silica or silica-alumina.

[0074] The oxide support may also advantageously further contain from 0.1 to 80% by weight, preferably from 0.1 to 50% by weight of zeolite relative to the total weight of the support. In this case, all known zeolite sources and associated preparation methods may be incorporated. Preferably, the zeolite is selected from the group FAU, BEA, ISV, IWR, IWW, MEI, UWY and more preferably, the zeolite is selected from the group FAU and BEA, such as zeolite Y and / or beta, and particularly preferably such as zeolite USY and / or beta.

[0075] The support is advantageously in the form of balls, extrudates, pellets or irregular and non-spherical agglomerates whose specific shape can result from a crushing step.

[0076] The oxide support advantageously has a total pore volume of between 0.1 and 1.5 mL / g, preferably between 0.4 and 1.1 mL / g. The total pore volume is measured by mercury porosimetry according to ASTM D4284-92 with a wetting angle of 140°, for example using an Autopore III™ model device from Microméritics™.

[0077] The specific surface area of ​​the oxide support is advantageously between 5 and 400 m 2 .g- 1 , preferably between 10 and 350 m 2 .g' 1 , more preferably between 40 and 350 m 2 .g' 1. The specific surface area is determined in the present invention by the BET method according to ASTM D3663. The active phase of the source catalyst comprises at least one metal from group VI B and / or at least one metal from group VIII. The metal from group VI B present in the active phase of the catalyst is preferably chosen from molybdenum and tungsten, or the mixture of these two elements. The metal from group VIII present in the active phase of the catalyst is preferably chosen from cobalt, nickel and the mixture of these two elements. The active phase of the catalyst is preferably chosen from the group formed by the combination of the elements nickel-molybdenum, cobalt-molybdenum, nickel-cobalt-molybdenum, nickel-tungsten, nickel-molybdenum-tungsten and nickel-cobalt-tungsten.

[0078] The Group VIII metal content is between 1 and 50% by weight of Group VIII metal oxide relative to the total weight of the source catalyst, preferably between 1 and 10% by weight, 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.

[0079] The Group VI B metal content is between 5 and 40% by weight of Group VI B metal oxide relative to the total weight of the source catalyst, preferably between 8 and 35% by weight, very preferably between 10 and 30% by weight. When the metal is molybdenum or tungsten, the metal content is expressed as MoOa and WO3 respectively.

[0080] The molar ratio of group VIII metal to group VIB metal in the catalyst, when the latter contains both types of metals, is preferably between 0.1 and 0.8, preferably between 0.15 and 0.6 and even more preferably between 0.2 and 0.6 or between 0.3 and 0.5.

[0081] The source catalyst may also include phosphorus as a dopant. A dopant is an added element that, in itself, has no catalytic properties but increases the catalytic activity of the active phase.

[0082] The phosphorus content in said source catalyst is then preferably between 0.1 and 20% by weight expressed as P2O5 relative to the total weight of the source catalyst, preferably between 0.2 and 15% by weight expressed as P2O5, and very preferably between 0.3 and 8% by weight expressed as P2O5.

[0083] The molar ratio of phosphorus to the group VIB element in the catalyst is greater than or equal to 0.05, preferably greater than or equal to 0.07, preferably between 0.08 and 1, preferably between 0.01 and 0.9 and very preferably between 0.15 and 0.6.

[0084] The source catalyst may comprise sulfur. The sulfur content in said source catalyst is then preferably between 1 and 15% by weight expressed as an element relative to the total weight of the source catalyst, preferably between 2 and 12%, and very preferably between 4 and 10% by weight. The sulfur content is measured by elemental analysis according to ASTM D5373.

[0085] The source catalyst comprises coke. It will be noted that the term "coke" in the present application refers to a hydrocarbon-based substance deposited on the surface of the catalyst during its use, highly cyclized and condensed and having an appearance similar to graphite.

[0086] The coke content, expressed as % by weight of the carbon element, 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 source catalyst. The coke content is determined according to the ASTM D5373 method.

[0087] The source catalyst is contaminated with arsenic. The arsenic content of the source catalyst is generally less than or equal to 25,000 ppm by weight relative to the total weight of the source catalyst, generally between 1 and 25,000 ppm by weight. Preferably, it is between 1,500 and 25,000 ppm by weight and more preferably between 2,500 and 20,000 ppm by weight relative to the total weight of the source catalyst.

[0088] The source catalyst is contaminated with vanadium. The vanadium content of the source catalyst is generally less than or equal to 50,000 ppm by weight relative to the total weight of the source catalyst, generally between 1 and 50,000 ppm by weight. Preferably, it is between 1,000 and 50,000 ppm by weight and more preferably between 4,000 and 30,000 ppm by weight relative to the total weight of the source catalyst.

[0089] Optionally, the source catalyst may contain other contaminants from the feedstock treated by the fresh catalyst from which it originated, such as nickel, iron, titanium, silicon, calcium, sodium, potassium, and chlorine.

[0090] The nickel content (contamination) of the source catalyst (in addition to that possibly present as an active phase on the fresh catalyst) is generally less than or equal to 30,000 ppm by weight relative to the total weight of the source catalyst. Preferably, it is between 0 and 30,000 ppm by weight, preferably between 1,000 and 30,000 ppm by weight, and more preferably between 4,000 and 10,000 ppm by weight relative to the total weight of the source catalyst.

[0091] The iron content of the source catalyst is generally less than or equal to 50,000 ppm by weight relative to the total weight of the source catalyst. Preferably, it is between 0 and 50,000 ppm by weight, preferably between 1,500 and 50,000 ppm by weight, and very preferably between 2,000 and 10,000 ppm by weight relative to the total weight of the source catalyst.

[0092] The titanium content of the source catalyst is generally less than or equal to 5000 ppm by weight relative to the total weight of the source catalyst. Preferably, it is between 0 and 5000 ppm by weight, preferably between 100 and 5000 ppm by weight, and very preferably between 200 and 2000 ppm by weight relative to the total weight of the source catalyst.

[0093] The silicon content of the source catalyst (in addition to that possibly present on the fresh catalyst) is generally less than or equal to 100,000 ppm by weight relative to the total weight of the source catalyst. Preferably, it is between 0 and 100,000 ppm by weight, preferably between 1,000 and 100,000 ppm by weight, and very preferably between 2,000 and 50,000 ppm by weight relative to the total weight of the source catalyst.

[0094] The calcium content of the source catalyst is generally less than or equal to 10,000 ppm by weight relative to the total weight of the source catalyst. Preferably, it is between 0 and 10,000 ppm by weight, preferably between 100 and 10,000 ppm by weight, and preferably between 500 and 5,000 ppm by weight relative to the total weight of the source catalyst.

[0095] The sodium content of the source catalyst (in addition to that possibly present on the fresh catalyst) is generally less than or equal to 10,000 ppm by weight relative to the total weight of the source catalyst. Preferably, it is between 0 and 10,000 ppm by weight, preferably between 100 and 10,000 ppm by weight, and more preferably between 500 and 5,000 ppm by weight relative to the total weight of the source catalyst.

[0096] The potassium content of the source catalyst is generally less than or equal to 20,000 ppm by weight relative to the total weight of the source catalyst. Preferably, it is between 0 and 20,000 ppm by weight, preferably between 100 and 20,000 ppm by weight, and preferably between 500 and 10,000 ppm by weight relative to the total weight of the source catalyst.

[0097] The chlorine content of the source catalyst is generally less than or equal to 5000 ppm by weight relative to the total weight of the source catalyst. Preferably, it is between 0 and 5000 ppm by weight, preferably between 100 and 5000 ppm by weight, and very preferably between 200 and 2000 ppm by weight relative to the total weight of the source catalyst.

[0098] The source catalyst from a hydrotreatment process of a middle distillate feedstock (diesel, kerosene) or a naphtha feedstock is distinguished by lower vanadium and nickel contents (in addition to the active phase) than that of a catalyst from a hydroconversion process of a heavier feedstock. The vanadium and nickel contents of a source catalyst from a hydrotreatment process of a middle distillate feedstock (diesel, kerosene) or a naphtha feedstock are generally less than or equal to 10,000 ppm by weight for nickel (in addition to the active phase), and less than or equal to 50,000 ppm by weight for vanadium relative to the weight of the source catalyst.

[0099] Pretreatments (optional)

[0100] The source catalyst may be subjected to at least one pretreatment step prior to the sulfuric acid extraction according to the method according to the invention. The optional pretreatment step consists of removing all or part of one or more of the impurities possibly contained in said source catalyst before the sulfuric acid extraction step, by any method known to those skilled in the art. The pretreatment step may be chosen from deoiling, grinding or even washing with water. These preliminary treatments are intended to make the extractions more efficient, by mechanical, physical or chemical treatments: grinding, for example, reduces the particle size of the source catalyst particles and increases the particle / extraction solution contact surface. Deoiling or washing with water work in the same direction, by improving / increasing the contact between the extraction solution and the contaminants contained in the source catalyst.

[0101] • Deoiling

[0102] The unloading of the source catalyst from a hydrotreatment and / or hydroconversion process is preferably preceded by a deoiling step. The deoiling step generally comprises contacting the source catalyst with a stream of inert gas (i.e. essentially free of oxygen), for example in a nitrogen atmosphere or the like, at a temperature between 300°C and 400°C, preferably between 300°C and 350°C. The inert gas flow rate in terms of flow rate per unit volume of the catalyst is 5 to 150 NL.h -1 for 3 to 7 hours. Alternatively, the deoiling step can be carried out by light hydrocarbons, by steam treatment or any other similar process.

[0103] The deoiling step is generally followed by a drying step and / or a heating step, preferably at a temperature between 50°C and 200°C. The drying gas is preferably an inert gas such as nitrogen.

[0104] • Grinding

[0105] The source catalyst, optionally deoiled, may advantageously undergo, before extraction with sulfuric acid, an optional grinding step in order to promote the kinetics of extraction of the metals during the process according to the invention. In this case, the step comprises a first optional phase of conditioning the source catalyst with at least one grinding so as to obtain catalyst particles having a size of at most 1 mm. It is of course possible to carry out several successive grinding steps in order to achieve the target particle size. Any method known to those skilled in the art may be implemented to carry out this crushing or grinding step, such as for example the use of a ball mill or a blade mill.Preferably, 90% of the volume distribution of the source catalyst particles have an equivalent diameter of between 1 and 1000 micrometers, preferably between 5 and 500 micrometers, preferably between 10 and 300 micrometers and particularly preferably between 15 and 150 micrometers. The equivalent diameter noted “de” is defined according to the following relationship de=6xV / S with V the volume of the particle and S the surface area of ​​the sphere of the same volume as the particle.

[0106] Most often, the ground source catalyst is brought into the extraction zone by any means known to those skilled in the art, in particular by a transfer screw or by pneumatic transfer.

[0107] • Washing with water

[0108] The source catalyst, possibly deoiled and / or ground, can undergo a water washing step.

[0109] The volume of water used in this washing step is advantageously greater than the total pore volume of the source catalyst. This volume may in particular be in a range from 2 to 20 times the total pore volume of the source catalyst, preferably between 5 and 10 times said pore volume.

[0110] The washing step may be carried out at any suitable temperature, for example between 5°C and 150°C, preferably between room temperature (20°C) and 70°C.

[0111] During the washing step, it is advantageous to mix the source catalyst to ensure efficient washing. The washing step can be carried out in continuous or batch mode, with batch mode being preferred as it limits the amount of water used. The washing step can be carried out in any solid / liquid extractor or industrial mixer type unit.

[0112] Vanadium extraction step with sulfuric acid

[0113] According to the method according to the invention, at least a portion of the vanadium from said source catalyst is extracted using an extraction solution comprising at least sulfuric acid, to obtain a vanadium-depleted source catalyst. The objective of this extraction step is to extract at least a portion of the vanadium while limiting the extraction of the active phase, the metals of group VIII and / or VI B. This is notably possible thanks to the presence of coke on the catalyst. Without being bound by any theory, it would appear that the coke present in the catalyst protects the extraction of the active phase, notably the extraction of the metal of group VI B while the contaminants which are on the surface of the catalyst are extracted.

[0114] The extraction solution is generally an aqueous solution comprising at least sulfuric acid. The extraction solution has a pH generally between 0.1 and 2, preferably between 0.1 and 1, preferably between 0.1 and 0.4.

[0115] The sulfuric acid concentration of the extraction solution is generally between 0.5 and 3 mol / L, preferably between 0.8 and 2.5 mol / L, and particularly preferably between 1 and 2 mol / L.

[0116] The selectivity of vanadium extraction with respect to the metal of group VIII and / or VI B can be significantly increased by adding an alcohol to the extraction solution. Thus, the extraction solution, in addition to sulfuric acid, preferably comprises an alcohol. The applicant has demonstrated that a combination of sulfuric acid and alcohol makes it possible to observe a synergistic effect for the selectivity of vanadium extraction. An extraction solution comprising sulfuric acid and an alcohol thus makes it possible to extract less metal of group VIII and / or VI B with respect to vanadium than a solution comprising only sulfuric acid.

[0117] The alcohol may be chosen from at least one of the following compounds: methanol, ethanol, 1-propanol, 2-propanol (or isopropanol), 1-butanol, 2-butanol, 2-methyl-1-propanol, tert-butanol, 1,2-ethanediol (or ethylene glycol), 1,2-propanediol (or propylene glycol), 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol and 1,6-hexanediol. Preferably, the alcohol is ethanol.

[0118] The alcohol concentration is greater than 250g / L, preferably greater than 350g / L and even more preferably greater than 500g / L.

[0119] In one embodiment according to the invention, the extraction solution comprising sulfuric acid may also contain an oxidant to promote the extraction of metals. Preferably, the oxidant contained in the extraction solution is hydrogen peroxide. When an oxidant is present, the concentration is generally between 0.1 and 5.0 mol / L.

[0120] The contacting of the source catalyst with the extraction solution is carried out under the following conditions: The temperature is generally between 0 and 300°C, preferably between 10 and 100°C, and more preferably between 15 and 40°C. In a particularly preferred manner, the temperature is room temperature.

[0121] The pressure is generally between atmospheric pressure and 20 bars (2 MPa), particularly between atmospheric pressure and 10 bars (1 MPa).

[0122] The contact time per extraction step is generally between 1 minute and 20 hours, preferably between 5 and 300 minutes, and most preferably between 5 and 120 minutes.

[0123] Preferably, this step is carried out by bringing the source catalyst into contact with a volume of said solution of between 1.5 and 60 times the volume of the source catalyst. Preferably, the volume of said solution is of between 2 and 30 times the volume of the source catalyst and more preferably of between 2 and 20 times the volume of the source catalyst, and particularly preferably of between 2 and 10 times the volume of the source catalyst.

[0124] 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.

[0125] All contacting modes in a single step or in several steps following a co-current, counter-current or cross-current mode are possible for the implementation of the extraction step in continuous mode. The extraction step includes contacting the sulfuric acid extraction solution with the source catalyst, then a solid / liquid separation step making it possible to obtain, on the one hand, a leached catalyst depleted in contaminants but containing the majority of the active phase, and, on the other hand, the extraction solution enriched in contaminants and containing as little extracted active phase as possible.

[0126] The extraction solution may be brought into contact with the source catalyst by any method known to those skilled in the art, for example by suspending the source catalyst in the extraction solution using a rotary stirrer or by fluidization, or by percolation of the leaching solution through a fixed bed containing the source catalyst.

[0127] The liquid / solid separation can be carried out by any method known to those skilled in the art, for example by sedimentation, by filtration, by draining, for example by gravity, and / or by centrifugation.

[0128] The extraction step with an extraction solution comprising sulfuric acid and advantageously also an alcohol thus makes it possible to extract most of the vanadium. This extraction step also makes it possible to extract other contaminants, such as nickel (contamination), iron, titanium, but also silicon, calcium, sodium and potassium. Only the arsenic contaminant generally remains in the leached catalyst.

[0129] The extraction rate of vanadium is generally greater than 10%, preferably greater than 15%, more preferably greater than 20%. Preferably, the extraction rate of vanadium is between 10 and 100%, preferably between 15 and 100%, and more preferably between 20 and 100%. The extraction rate corresponds to the mass of vanadium in the extraction solution relative to the mass of vanadium initially present on the source catalyst.

[0130] The extraction rate of nickel (contamination), iron, titanium, silicon, calcium, sodium and potassium is generally greater than 5% respectively, preferably greater than 10%, more preferably greater than 15%.

[0131] The arsenic extraction rate is generally less than 20%, preferably less than 10%, more preferably less than 5%.

[0132] The extraction rate corresponds to the mass of the contaminant in the extraction solution relative to the mass of the contaminant initially present on the source catalyst.

[0133] Although not desired, this extraction step may also extract a minor portion of the active phase, as well as a minor portion of phosphorus (possibly present in the source catalyst) and alumina (from the support) possibly present in the source catalyst.

[0134] The extraction rate of the group VIII metal is generally less than 50%, preferably less than 40%, more preferably less than 30%. Preferably, the extraction rate of the group VIII metal is between 0 and 50%, preferably between 0 and 40%, and more preferably between 0 and 30%.

[0135] The extraction rate of the group VI B metal is generally less than 20%, preferably less than 10%, more preferably less than 8%. Preferably, the extraction rate of the group VI B metal is between 0 and 20%, preferably between 0 and 10%, and more preferably between 0 and 8%.

[0136] The extraction rate corresponds to the mass of the extracted metal(s) in the extraction solution relative to the mass of metal(s) initially present on the source catalyst. The extraction rate of phosphorus and aluminum is preferably less than 40% respectively, preferably less than 30%, more preferably less than 25%. The extraction rate corresponds to the mass of phosphorus or aluminum in the extraction solution relative to the mass of phosphorus or aluminum initially present on the source catalyst.

[0137] The extraction step comprising sulfuric acid and advantageously an alcohol may be followed by a washing step with the extraction solvent or with water, then a drying step and / or a heating step, preferably at a temperature between 50°C and 200°C. The drying gas is preferably an inert gas such as nitrogen.

[0138] At the end of the sulfuric acid extraction stage, we obtain, on the one hand, a leached catalyst depleted in vanadium but still containing the majority of the active phase and arsenic.

[0139] Regeneration

[0140] According to the present invention, a regeneration of said sourced catalyst depleted in vanadium from the extraction step is carried out with an extraction solution comprising sulfuric acid and advantageously an alcohol.

[0141] The regeneration step allows all or part of the coke to be removed, as well as any sulfur and / or chlorine deposited on the catalyst. The regeneration step also makes the active phase accessible for extraction by an extraction solution comprising at least one organic compound having complexing properties in the following step.

[0142] 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 in terms of flow rate per unit volume of the source catalyst is preferably 20 to 2000 NL.tr 1 , more preferably from 30 to 1000 NL.h-1, and particularly preferably from 40 to 500 NL.tr 1 The duration of the regeneration is preferably 2 hours or more, more preferably 2.5 hours or more, and particularly preferably 3 hours or more. The regeneration of the source catalyst is generally carried out at a temperature between 320°C and 550°C, preferably between 360 and 500°C.

[0143] The regenerated source catalyst is composed of the oxide support and the active phase formed of at least one Group VIB metal and / or at least one Group VIII metal and optionally phosphorus from the source catalyst. The regenerated source catalyst contains substantially the same Group VIB and / or VIII metal content as the source catalyst. The regenerated catalyst contains substantially the same contaminant content as before regeneration with the exception of coke, sulfur and chlorine.

[0144] The regenerated source catalyst is characterized by a specific surface area of ​​between 20 and 300 m 2 / g, preferably between 30 and 280 m 2 / g, preferably between 40 and 260 m 2 / g, very preferably between 80 and 250 m 2 / g.

[0145] The pore volume of the regenerated source catalyst is generally between 0.1 cm 3 / g and 1.3 cm 3 / g, preferably between 0.2 cm 3 / g and 1.1 cm 3 / g.

[0146] The regenerated source catalyst obtained in the regeneration step contains residual carbon at a content of less than 3% by weight relative to the total weight of the regenerated catalyst, preferably between 0% and 2.9% by weight relative to the total weight of the regenerated catalyst, preferably between 0% and 2.0% by weight and particularly preferably between 0% and 1.0% by weight. The sulfur content after regeneration is preferably between 0 and 4% by weight expressed as an element relative to the weight of the catalyst, preferably between 0 and 2% by weight. 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, preferably between 0 and 0.15% by weight. active in

[0147] According to the method according to the invention, an extraction of the metal from group VIB and / or the metal from group VIII is carried out from said regenerated source catalyst by an extraction solution comprising at least one organic compound having complexing properties, to obtain a solution of extracted metal / metals from group VIB and / or group VIII.

[0148] The objective of this step is to maximize the extraction rate of group VIB and / or VIII metal while limiting the extraction of arsenic.

[0149] The extraction solution of this step may comprise any polar protic solvent known to those skilled in the art. Preferably, a polar protic solvent is used, for example chosen from the group formed by methanol, ethanol, and water, or a water-ethanol or water-methanol mixture. Very preferably, the solvent used in the impregnation solution consists of water. In the case of an aqueous solution, the pH of said solution may be modified by the possible addition of an acid or a base. The extraction solution has a pH generally between 0.1 and 8.5, preferably between 0.5 and 6, preferably between 1 and 4. Preferably, the extraction solution and the impregnation solution of the following step have at least one solvent in common. They may have an identical solvent or mixture of solvents, or varying by the proportion of solvents in the case of a mixture.For example, it may be water, or a mixture of solvents comprising mainly, or essentially, an aqueous solvent.

[0150] Preferably, the extraction of the metals is carried out with a solution comprising a solvent, in particular aqueous, and at least one organic compound having complexing properties, and possibly also acids (either at least one compound having both properties, or the combination of at least one acid compound and at least one complexing compound, or only at least one complexing compound for example).

[0151] It has indeed been shown that adding an organic compound to the solution (generally aqueous) is very effective in extracting the metals of interest that we want to recycle, by making them pass into the liquid phase, while the support of the regenerated source catalyst and any other components, including arsenic, of the regenerated source catalyst remain largely in the solid phase and are thus easily eliminated.

[0152] It should be noted that the organic compounds that give the most interesting results are often compounds with acidic and complexing properties. Indeed, an organic acid allows the metal oxide to be protoned, thus limiting its interaction with the support and promoting its dissolution in the extraction solution. A complexing agent allows the formation of a metal complex that is soluble in the extraction solution. The combination of acidic and complexing properties is therefore particularly interesting: the use of an organic compound with these two properties or the combination of an acidic organic compound and a complexing organic compound is therefore particularly indicated.

[0153] This organic compound, or at least one of them when there are several, may comprise one or more chemical functions chosen from a carboxylic acid, phosphoric acid, sulfonic acid, alcohol, thiol, thioether, sulfone, sulfoxide, ether, aldehyde, ketone, ester, carbonate, amine, nitrile, imide, oxime, urea and amide function, or even compounds including a furanic cycle or even sugars.

[0154] The organic compound (or at least one of them when there are several) having both acidic and complexing properties can 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.,

[0155] The organic compound (or at least one of them when there are several) having complexing properties can 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 of between 200 and 1500 g / mol), propylene glycol, glycerol, 2-butoxyethanol, 2-(2-butoxyethoxy)ethanol, 2-(2-methoxyethoxy)ethanol, triethylene glycol dimethyl ether, crown ether, acetophenone, 2,4-pentanedione, pentanone, glucose, fructose, sucrose,sorbitol, xylitol, mannitol, y-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, 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.,

[0156] The concentration of each organic compound in 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 are present, the different molar ratios apply for each of the organic compounds present.

[0157] The concentration of each organic compound 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.

[0158] The extraction solution comprising at least one organic compound having complexing and possibly acidic properties is chosen so as to maximize the extraction rate of the group VI B and / or VIII metal while limiting the extraction of arsenic.

[0159] The choice of certain organic compounds allows us to observe a high selectivity of extraction of the metal of group VIII and the metal of group VIB compared to arsenic, which remains largely in the leached catalyst.

[0160] According to a preferred variant, the organic compound is chosen from a carboxylic acid which preferably comprises between 1 and 8 carbon atoms and which may be a mono-acid, di-acid or tri-acid. Preferably, the organic compound is chosen from formic acid, acetic acid, glutaric acid, oxalic acid, glycolic acid, lactic acid, citric acid, γ-ketovaleric acid, acetoacetic acid and gluconic acid.

[0161] According to another preferred variant, the organic compound is chosen from fructose, diethylene glycol and triethylene glycol.

[0162] According to a very preferred variant, 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.

[0163] Furthermore, for the same organic compound, it is observed that the extraction rate of the group VIII and / or group VIB metal can be improved by using a higher concentration of this organic compound in the extraction solution. It is thus generally observed that the extraction rate of the group VIII and / or VIB metal can be increased by using an extraction solution with a higher concentration of organic compound, but that the arsenic extraction rate remains stable. The concentration of organic compound in the extraction solution is preferably between 0.5 and 1 mol / L.

[0164] The choice of certain organic compounds, combined with a high concentration of this organic compound in the extraction solution, thus makes it possible to significantly increase the extraction rate of the group VIII and / or group VIB metal while observing a stable extraction rate of arsenic. This is particularly the case when the organic compound is chosen from acetic acid, oxalic acid, citric acid, γ-ketovaleric acid, fructose, ethylene glycol, diethylene glycol and triethylene glycol, combined with a concentration of organic compound in the extraction solution between 0.5 and 1 mol / L.

[0165] In one embodiment according to the invention, the extraction solution may also contain phosphorus. The presence of phosphorus promotes the extraction of metals, and in particular molybdenum, due to the high stability of the heteropolyanions that this metal forms with phosphorus. The addition of phosphorus in the form of phosphoric acid H3PO4 also makes it possible to lower the pH of the solution, which is also generally beneficial for the extraction of the metals contained in the source catalyst. Mineral acids other than phosphoric acid may also be used, in particular nitric acid or boric acid. It should be noted that the use of sulfuric acid, a conventional metal extraction agent, is not recommended. Indeed, an extraction solution comprising sulfuric acid shows a low VIB / As or VIII / As ratio.Sulfuric acid is therefore not a selective extraction agent and extracts a lot of arsenic along with group VI B and / or VIII metals. The extraction solution therefore preferably does not include sulfuric acid.

[0166] In one embodiment according to the invention, the extraction solution may also contain an oxidant to promote the extraction of metals. Preferably, the oxidant contained in the extraction solution is hydrogen peroxide. When an oxidant is present, the concentration is generally between 0.1 and 5.0 mol / L.

[0167] In general, the operating conditions of the extraction step according to the invention are chosen so as to maximize the extraction of the metals of group VI B and / or VIII contained in the regenerated source catalyst, while minimizing the dissolution of the arsenic of said regenerated source catalyst, and limiting as much as possible the quantity of organic compound so that the latter is not in too great an excess compared to the optimal quantity of organic compound necessary for the impregnation step to obtain high-performance catalysts. It is also sought to minimize the quantity of extraction solution to be used, in order to obtain the most concentrated metal solution possible at the end of extraction: this limits the need to concentrate the solution before using it in the impregnation solution or as an impregnation solution.

[0168] Contact is carried out with the extraction solution under the following conditions:

[0169] The temperature is generally between 0 and 300°C, preferably between 10 and 100°C, and more preferably between 15 and 40°C. Particularly preferably, the temperature is room temperature. The pressure is generally between atmospheric pressure and 20 bars (2 MPa), in particular between atmospheric pressure and 10 bars (1 MPa).

[0170] The contact time per extraction step is generally between 1 minute and 20 hours, preferably between 5 and 300 minutes, and most preferably between 5 and 120 minutes.

[0171] The amount of extraction solution used for this step is preferably as small as possible to obtain the desired effect, as indicated above. Preferably, this step is carried out by bringing the regenerated source catalyst into contact with a volume of said solution of between 1.5 and 60 times the volume of the source catalyst. Preferably, the volume of said solution is between 2 and 30 times the volume of the regenerated source catalyst and more preferably between 2 and 20 times the volume of the regenerated source catalyst, and particularly preferably between 2 and 10 times the volume of the regenerated source catalyst.

[0172] When the tool(s) performing the contacting do not have heating equipment, and the temperature of the contacting is regulated by the temperature of the extraction solution. It may therefore be at room temperature, or have been heated, for this specific contacting step. It may also be at a given temperature, in particular above room temperature, because it comes, at least in part, from the recycling of liquid effluents produced during its use as an impregnation solution and already in this temperature range.

[0173] 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.

[0174] All contacting modes in a single step or in several steps following a co-current, counter-current or cross-current mode are possible for the implementation of the extraction step in continuous mode. The extraction step includes contacting the extraction solution with the regenerated source catalyst, then a solid / liquid separation step making it possible to obtain, on the one hand, a leached catalyst depleted in metal / metals of group VI B and / or VIII but containing the majority of the arsenic, and, on the other hand, the extraction solution enriched in a metal of group VI B and / or a metal of group VIII and containing as little arsenic as possible.

[0175] The extraction solution may be brought into contact with the regenerated source catalyst by any method known to those skilled in the art, for example by suspending the regenerated source catalyst in the extraction solution using a rotary stirrer or by fluidization, or by percolation of the leaching solution through a fixed bed containing the regenerated source catalyst.

[0176] The liquid / solid separation can be carried out by any method known to those skilled in the art, for example by sedimentation, by filtration, by draining, for example by gravity, and / or by centrifugation. The remaining solid residue can be washed with the extraction solvent and / or with water. It can also be dried.

[0177] According to one embodiment, when the source catalyst contains only a group VI B metal or a group VIII metal respectively, a fortiori only a group VI B metal or a group VIII metal is extracted from the catalyst. According to another embodiment, when the source catalyst contains both at least one group VI B metal and at least one group VIII metal, and either only the group VI B or group VIII metal respectively, or both the group VI B metal and the group VIII metal are extracted.

[0178] At the end of the extraction step, we obtain, on the one hand, a leached catalyst depleted in metal / metals but containing the majority of the arsenic, and, on the other hand, the extraction solution enriched in at least one metal from group VIB and / or at least one metal from group VIII and containing as little arsenic as possible.

[0179] Preferably, the residual content of metals from group VIB and / or VIII of the catalyst depleted in metal / metals (sum of the contents of the different metals contained in the leached catalyst expressed as oxide) is less than 10% by weight, preferably less than 5% by weight and very preferably less than 2% by weight relative to the weight of the catalyst depleted in metal / metals.

[0180] The extraction rate of the group VIII metal is generally greater than 50%, preferably greater than 60%, more preferably greater than 70%. Preferably, the extraction rate of the group VIII metal is between 50 and 100%, preferably between 60 and 100%, and more preferably between 70 and 100%.

[0181] The extraction rate of the group VIB metal is generally greater than 50%, preferably greater than 60%, more preferably greater than 70%. Preferably, the extraction rate of the group VIB metal is between 50 and 100%, preferably between 60 and 100%, and more preferably between 70 and 100%.

[0182] The extraction rate corresponds to the mass of the extracted metal(s) in the extraction solution relative to the mass of metal(s) initially present on the source catalyst. The arsenic extraction rate is preferably less than 30%, preferably less than 20%, more preferably less than 15% and even more preferably less than 10%.

[0183] Other contaminants may still be present as the sulfuric acid extraction may not be exhaustive.

[0184] Titanium and iron contaminants, like arsenic, are generally poorly extracted and remain largely in the leached catalyst. Similarly, a low content of phosphorus (from the source catalyst when present) and aluminum (from the source catalyst support) can be observed in the extraction solution. The extraction rate of phosphorus, aluminum, titanium and iron is respectively preferably less than 30%, preferably less than 20%, more preferably less than 15% and even more preferably less than 10%.

[0185] The contaminants vanadium (remaining after extraction with sulfuric acid), nickel (contaminant from the feedstock and not from the active phase and remaining after extraction with sulfuric acid), silicon, sodium, calcium and potassium are distributed between the extraction solution and the leached catalyst. The extraction rate of vanadium, nickel (contaminant), silicon, sodium, calcium and potassium is respectively generally between 20 and 70%, preferably between 25 and 65%, most preferably between 25 and 60%.

[0186] The extraction rate corresponds to the mass of the contaminant in the extraction solution relative to the mass of the contaminant initially present on the source catalyst.

[0187] Contaminants vanadium, nickel (contaminant from the charge and not from the active phase), silicon, sodium, calcium and potassium are distributed between the extraction solution and the leached catalyst, so they can be found in significant quantities in the extraction solution.

[0188] In this case, their contents in the impregnation solution can be reduced by dilution (e.g. with another extraction solution containing no or fewer contaminants). Alternatively, it is also possible to add a metal from group VIII and / or VIB to the extraction / impregnation solution containing too many contaminants.

[0189] Extraction solution treatment step(s) before impregnation (optional)

[0190] 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 treatments: purification, concentration, dilution, modification of the composition of the solution by addition or elimination, total or partial, of at least one compound. The extracted metal(s) remain in liquid phase during these treatments.

[0191] • Purification

[0192] The extracted metal / metal solution may be subjected to a purification step. The purpose of purification is to remove all or part of the impurities possibly contained in the metal solution, in particular impurities potentially present on the source catalyst or linked to a partial dissolution of the support of said catalyst. Purification may take place in a single step or in several successive steps.

[0193] In the event that the extracted metal(s) solution contains suspended solids after the final liquid / solid separation step, any known method for removing these suspended materials may be used. Preferably, this removal is carried out by filtration (e.g., microfiltration and ultrafiltration on a cross-flow filter). Other methods are centrifugation, coagulation or sedimentation.

[0194] For dissolved impurities, such as arsenates or arsenites, all known methods may be used, including, and preferably, sorption on solids, precipitation and solvent extraction, taking care not to remove at the same time the metals of interest which have been extracted.

[0195] • Concentration

[0196] The extracted metal / metal solution, optionally purified, may be subjected to a concentration step. This step consists of concentrating the extracted metal / metal solution, by removing part of the solvent, and possibly all or part of the organic compound contained in the metal solution. This step may be necessary if the metal concentrations are too low compared to the concentrations necessary to carry out an impregnation. Any known method for removing part of a solvent from a solution is envisaged. The concentration may take place in a single step or in several successive steps. All or part of the solvent, whether or not containing the organic compound, extracted from the metal solution may be recycled in the process according to the invention as an extraction solution.

[0197] Preferably, and in particular in the case where the metal solution is an aqueous solution, the concentration is carried out by evapoconcentration. In this case, neutralization will preferably be carried out, so that the effluent enters the evaporator in a pH range of 5 to 7. This pH regulation makes it possible to limit co-distillation phenomena, unless this is sought for the co-elimination of the solvent and part of the organic compound and, moreover, to avoid as much as possible the precipitation of metal oxides. Preferably, all or part of the distillate can be recycled in the process according to the invention as an extraction solution.

[0198] When only the removal of a portion of the solvent is desired, in addition to evaporation concentration, the preferred techniques are membrane techniques, and, very preferably, nanofiltration, reverse osmosis and pervaporation, solvent extraction or cryoconcentration.

[0199] When one wants to remove solvent and organic compound(s) when they are used, a preferred technique is evapoconcentration.

[0200] • Adjustment of the composition of the metal solution

[0201] The extracted metal(s) solution, optionally purified and / or concentrated, may be subjected to a composition adjustment step. This step consists of modifying the metal solution by adding(s) and / or removing(s) certain constituents. Metal precursors and / or phosphorus precursors and / or organic additives may be added. Organic compounds 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 corresponds to that desired for the impregnation solution used for the synthesis of a new catalyst.

[0202] Even if it is desired that the catalyst obtained according to the invention has a formulation identical to that of the source catalyst, the ratios between metals in the metal solution are potentially to be adjusted, on the one hand because the purification of the catalyst can modify the initial metal contents of the source catalyst, and on the other hand because the extraction step can induce different extraction rates for each of the metals.

[0203] The adjustment of the ratios between metals is done either by adding a make-up solution containing one or more of said metals, or by direct dissolution of one or more metal precursors in the extracted metal / metal solution(s), the latter alternative being preferred. The molar ratio of group VIII metal to group VI B metal in the metal solution at the end of this adjustment step is generally between 0.1 and 0.8, preferably between 0.15 and 0.6.

[0204] As an example for metal precursors, among the sources of molybdenum, it is possible to use oxides and hydroxides, molybdic acids and their salts, in particular ammonium salts such as ammonium molybdate, ammonium heptamolybdate, phosphomolybdic acid (H3PM012O40), and their salts, and possibly silicomolybdic acid (H4SiMoi2C>4o) and its salts. The sources of molybdenum can also be any heteropolycompound of the Keggin, lacunar Keggin, substituted Keggin, Dawson, Anderson, Strandberg type, for example. Molybdenum trioxide and heteropolycompounds of the Keggin, lacunar Keggin, substituted Keggin and Strandberg type are preferably used.

[0205] The tungsten precursors that can be used are also well known to those skilled in the art. For example, among the tungsten sources, it is possible to use oxides and hydroxides, tungstic acids and their salts, in particular ammonium salts such as ammonium tungstate, ammonium metatungstate, phosphotungstic acid and their salts, and possibly silicotungstic acid (H4SiWi204o) and its salts. The tungsten sources can also be any heteropolycompound of the Keggin, vacated Keggin, substituted Keggin, or Dawson type, for example. Preferably, ammonium oxides and salts such as ammonium metatungstate or heteropolyanions of the Keggin, vacated Keggin, or substituted Keggin type are used.

[0206] The cobalt precursors that can be used are advantageously chosen from oxides, hydroxides, hydroxycarbonates, carbonates and nitrates, for example. Cobalt hydroxide and cobalt carbonate are preferably used. It can also be cobalt acetoacetate.

[0207] Nickel precursors that can be used are advantageously chosen from oxides, hydroxides, hydroxycarbonates, carbonates and nitrates, for example. It can also be nickel acetoacetate.

[0208] If the phosphorus / metal ratio of the extracted metal / metal solution is lower than that desired for the impregnation solution, a phosphorus precursor, identical or different from that optionally used in the extraction step, may be added to the extracted metal / metal solution. This will be the case in particular when no phosphorus compound / precursor has been added to the extraction solution, or when it has been consumed at least in part by the support, when it contains alumina, to form alumino-phosphates. In this case, the molar ratio of phosphorus to the group VI B metal is between 0.1 and 2.5 mol / mol, preferably between 0.1 and 2.0 mol / mol, and even more preferably between 0.1 and 1.0 mol / mol or between 0.15 and 0.8 mol / mol, or between 0.2 and 0.6 mol / mol.

[0209] The preferred phosphorus precursor is phosphoric acid H3PO4, but its esters and salts such as ammonium phosphates are also suitable, as are polyphosphates. Phosphorus can also be introduced together with the group VI B element(s) in the form of Keggin, vacated Keggin, substituted Keggin, or Strandberg-type heteropolyanions.

[0210] The addition of an organic additive to hydrotreatment / hydroconversion catalysts has been recommended by those skilled in the art to improve their activity. They are known to improve the dispersion of metals on the surface of the support and / or to play a beneficial role during the sulfurization of the catalysts. Thus, one or more organic additives well known to those skilled in the art can be advantageously added at this stage. Generally, the amount of each organic additive added is defined so that the additive / metal molar ratio is between 0.1 and 1 in the impregnation solution.

[0211] Patent FR3083134 describes examples of organic additives that may be suitable and that can be used in aqueous form, and that can therefore be added to the impregnation solution. Patent FR3083131 also describes examples of organic additives that may be suitable, but which will rather be added separately, in pre-impregnation or post-impregnation of the support.

[0212] The extracted metal / metal solution may contain an excess of organic compounds compared to the desired impregnation solution. The ratios between organic compounds and metals can be adjusted in two ways. The first way 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 obtained will contain a mixture of recycled and new metals.

[0213] If the excess organic compound is too large to use the first method (i.e. the quantity of recycled metals incorporated into the final catalyst is not significant, for example less than 5% of the total quantity of metals), the second method then consists of removing all or part of the excess organic compound from the metal solution. In this case, the organic compound can be recycled to the extraction step. For this, any method known to those skilled in the art for separating an organic molecule from a metal solution is considered. The concentration of excess organic compound can be reduced, for example, by evaporation, liquid-liquid extraction, adsorption or membrane separation.

[0214] Impregnation stage

[0215] The extracted metal / metal solution, possibly previously subjected to one or more of the treatments described below, can be used for the preparation of a new catalyst. According to the method according to the invention, a support is impregnated with an impregnation solution derived from said extracted metal / metal solution, to obtain an impregnated substrate, said extracted metal(s) remaining in the liquid phase from extraction until impregnation.

[0216] According to the present invention, the term "support" (which will be impregnated with the impregnation solution resulting from the solution of extracted metal(s)) means a "new" support of oxides, but also a support which has already been impregnated with another impregnation solution - we speak of a pre-impregnated support -, or a support which is in fact a catalyst (a support provided with metals) but which contains an insufficient quantity of metals, such as a used or regenerated catalyst.

[0217] Impregnation can be carried out by any known method, for example ion exchange, dry impregnation, excess impregnation, vapor deposition, etc. Contacting can take place in one step or in several successive steps.

[0218] According to a preferred embodiment, the impregnation of said support with the impregnation solution is carried out by excess impregnation or by dry impregnation. Equilibrium or excess impregnation consists of immersing the support or catalyst in a volume of solution (often largely) greater than the pore volume of the support or catalyst. Dry impregnation consists of introducing a volume of impregnation solution equal to or slightly less than the pore volume of the support or catalyst. Dry impregnation makes it possible to deposit all of the constituents of the impregnation solution on a given support or catalyst. The impregnation step can advantageously be carried out by one or more excess impregnations of solution or preferably by one or more dry impregnation(s), and, for example, by a single excess impregnation, using the impregnation solution.According to the present invention, "impregnation" is understood to mean that there is an impregnation step, but that the impregnation may be carried out by one or a plurality of successive impregnation operations.

[0219] The impregnation is carried out at a temperature generally between 10°C and 95°C, at a pressure between atmospheric pressure and 20 bars (2 MPa), preferably at atmospheric pressure, and for a duration preferably between 1 minute and 20 hours, preferably between 1 and 300 minutes. The impregnation is preferably carried out at a temperature between 10°C and 60°C, preferably at room temperature.

[0220] Advantageously, after each impregnation step, the impregnated support or catalyst is allowed to mature. Maturation allows the impregnation solution to disperse homogeneously within the support or catalyst. Each maturation step 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 room temperature. Generally, a maturation time of between 10 minutes and 48 hours, and preferably between 30 minutes and 6 hours, is sufficient.

[0221] Advantageously, the impregnation step is followed by a drying step at a temperature below 200°C, preferably between 50 and 180°C, more preferably between 70 and 150°C, and very preferably between 75 and 130°C. The drying step is preferably carried out for a period of between 10 minutes and 24 hours. Longer periods are not excluded, but do not necessarily provide an improvement. The drying step can be carried out by any known technique. It is advantageously carried out at atmospheric pressure or at reduced pressure. Preferably, this step is carried out at atmospheric pressure. It is advantageously carried out using air or any other hot gas. Preferably, the gas used is either air or an inert gas such as argon or nitrogen. Very preferably, the drying is carried out in the presence of nitrogen and / or air and is advantageously carried out in a traversed bed.

[0222] According to one variant, the drying is advantageously carried out so as to preferably retain at least 30% by weight of the organic additive introduced during a possible adjustment of organic compound after the extraction step to the organic compound and / or introduced during the 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.

[0223] According to one variant, the drying is advantageously carried out so as to preferably retain at least 30% by weight of the organic extraction compound 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.

[0224] Optionally, the drying can be followed by a calcination step. This may be the case, for example, if it is desired to eliminate all or part of one or more organic extraction compounds. According to this variant, at the end of 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 (nitrogen for example) or under an atmosphere containing oxygen (air for example). The duration of this heat treatment is generally between 0.5 hours and 16 hours, preferably between 1 hour and 5 hours. After this treatment, the active phase is thus generally in oxide form, the heteropolyanions are thus transformed into oxides. Similarly, the catalyst no longer contains or contains very little organic extraction compound and organic additive.However, the introduction of the organic additive during its preparation made it possible to increase the dispersion of the active phase, thus leading to a more active catalyst.

[0225] Preferably, the catalyst is not subjected to calcination.

[0226] In the embodiment in which the impregnation step is carried out via at least two impregnation cycles, each impregnation is advantageously followed by drying and possibly calcination.

[0227] The "new" oxide support which will be impregnated with the impregnation solution resulting from the extracted metal / metal(s) solution can be of the same nature as the source catalyst support, a description of which has already been given above.

[0228] The support may also contain at least a portion of the metal(s) VI B and VIII, and / or at least a portion of the phosphorus and / or at least a portion of the sulfur and / or at least a portion of the organic additive(s) apart from those which may be introduced during the step of adjusting the composition of the metal solution and / or the impregnation step. They are introduced for example during the preparation of the support. This is then referred to as a “pre-impregnated” support.

[0229] It is also possible to add one or more metals to the support already impregnated with the impregnation solution according to the invention. This is called a “post-impregnated” support.

[0230] In both cases, "pre-impregnated" or "post-impregnated" support, the aim is the same: it is a question of adjusting the metal content of the final catalyst, either by adding a certain quantity of the metal(s) present in the impregnation solution according to the invention, or by adding one or more other metals in a separate step, with another impregnation solution in particular, before and / or after the impregnation step with the impregnation solution of the invention.

[0231] A catalyst already containing one or more metals can also be brought into contact with the solution of extracted metal(s). This can be a catalyst that has been depleted of metals, and in particular be a spent catalyst itself, possibly regenerated and then optionally rejuvenated.

[0232] The active phase of the recycled catalyst targeted by the process according to the invention is generally of the type already described above for the so-called source catalyst. It should be noted that the new catalyst may have a different formulation from the source catalyst used to recover the metals and different quantities of metal and different ratios between metals: thus, a used catalyst highly loaded with metals can, according to the invention, be used to produce a catalyst with a lower metal load (or vice versa). This makes it possible, where appropriate, to avoid a step of concentrating the solution after extraction or at least to reduce its intensity / duration.The recycled catalyst can then be used differently (on different hydrocarbon feedstocks) than the source catalyst from which it originates (for example, a catalyst with 20% weight of Mo expressed as MoOa relative to the weight of the dry catalyst can be used for the hydrotreatment of distillates, while a catalyst with a lower Mo content, of 10% weight of Mo expressed as MoOa, can be used for the hydrotreatment of naphtha). Thus, a source catalyst can be used that does not have the same function as the recycled catalyst to be produced, as long as they have at least one metal in common (hydrotreatment catalyst, hydrocracking catalyst, Fischer-Tropsch catalyst), or that has the same function (hydrotreatment catalyst in both cases, for example).

[0233] It should also be noted that the new catalyst can be post-additive, that is to say 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 the non-additive catalysts, before the final optional sulfurization, it being understood that, preferably, no calcination step is carried out after its introduction.

[0234] The quantity of recycled metals contained in the new catalyst is between 1% and 100% by weight of the metals contained in the new catalyst, preferably between 10% and 100% by weight, more preferably between 20% and 100% by weight, and even more preferably between 50% and 100% by weight relative to the weight of the new catalyst.

[0235] Before use, the new catalyst can undergo an optional sulfurization step. Sulfurization is preferably carried out in a sulforeducing medium, i.e. in the presence of H2S and hydrogen, in order to transform the metal oxides into sulfides such as, for example, M0S2 and CogSs. Sulfurization is carried out by injecting the catalyst with a stream containing H2S and hydrogen, or a sulfur compound capable of decomposing into H2S in the presence of the catalyst and hydrogen. Polysulfides such as dimethyl disulfide (DM DS) are FLS precursors commonly used to sulfurize catalysts. Sulfur can also come from the feedstock. The temperature is adjusted so that H2S reacts with the metal oxides to form metal sulfides.This sulfurization can be carried out in situ or ex situ (inside or outside the reactor) of the reactor of the hydrotreatment or hydroconversion process according to the invention at temperatures between 200 and 600°C, and more preferably between 300 and 500°C.

[0236] According to a variant, at least part of the impregnation solution can be reused after impregnation of the support, in particular as a supplement to the extraction solution with the organic compound. This limits the consumption of solvent and organic compound (optional) in the process.

[0237] Examples

[0238] The starting point is a spent catalyst called CoMoP, containing molybdenum, cobalt and phosphorus deposited on an alumina support used in a hydrotreatment process and which has been contaminated with arsenic and vanadium. It has previously been washed with toluene and dried at 140°C under vacuum in order to eliminate any traces of hydrocarbons.

[0239] The spent catalyst contains molybdenum, phosphorus and cobalt. The composition of the catalyst is expressed in the form of oxides and related to the mass of dry catalyst: 19.4% by weight of MoOa (12.9% by weight of molybdenum), 3.8% by weight of CoO (3.0% by weight of cobalt, i.e. a Co / Mo molar ratio of 0.38) and 3.0% by weight of P2O5 (1.3% by weight of phosphorus, i.e. a P / Mo molar ratio of 0.31). It also contains 9200 ppm by weight of arsenic and 21100 ppm by weight of vanadium. It also contains 12.8% by weight of carbon and 8.7% by weight of sulfur.

[0240] Extraction with an aqueous solution containing 1.1 mol / L of sulfuric acid:

[0241] An extraction step of molybdenum and cobalt metals from this spent catalyst is carried out on a laboratory scale: 30 g of this contaminated spent catalyst (called source catalyst), previously ground to a particle size between 100 and 300 microns, and 75 mL of extraction solution are introduced into a flask. The extraction solution is an aqueous solution containing 1.1 mol / L of sulfuric acid. The mixture is stirred at room temperature at 200 rpm via a magnetic bar for 6 hours. The mixture is then filtered through a porosity 5 sintered glass, in order to recover a polymetallic solution on the one hand and a solid residue on the other. Analysis of the solution shows that it contains 4.9 g / L of molybdenum, 5.4 g / L of cobalt, 3.1 g / L of vanadium and 0.02 g / L of arsenic. The calculated extraction rates of Mo and Co are therefore 9% and 44% respectively, the extraction rate of vanadium is 36% and the extraction rate of arsenic is 0.5%.

[0242] Extraction with an aqueous solution containing 395 g / L of ethanol: A step of extraction of molybdenum and cobalt metals from this spent catalyst is carried out on a laboratory scale: 30 g of this contaminated spent catalyst (called source catalyst), previously ground to a particle size between 100 and 300 microns, and 75 mL of extraction solution are introduced into a flask. The extraction solution is an aqueous solution containing 395 g / L of ethanol. The mixture is stirred at room temperature at 200 rpm via a magnetic bar for 6 hours. The mixture is then filtered through a sintered glass of porosity 5, in order to recover a polymetallic solution on the one hand and a solid residue on the other hand. Analysis of the solution shows that it contains 0.2 g / L of molybdenum, 0.03 g / L of cobalt, 0.04 g / L of vanadium and 0.01 g / L of arsenic.The calculated extraction rates of Mo and Co are therefore 0.4% and 0.3% respectively, the extraction rate of vanadium is 0.4% and the extraction rate of arsenic is 0.3%.

[0243] Extraction with a solution containing ethanol and acid

[0244] An extraction step of molybdenum and cobalt metals from this spent catalyst is carried out on a laboratory scale: 30 g of this contaminated spent catalyst (called source catalyst), previously ground to a particle size between 100 and 300 microns, and 75 mL of extraction solution are introduced into a flask. The extraction solution is an aqueous solution obtained by mixing 4.5 mL of 1.1 mol / L sulfuric acid and 70.5 mL of 395 g / L ethanol. The mixture is stirred at room temperature at 200 rpm via a magnetic bar for 6 hours. The mixture is then filtered through a sintered glass of porosity 5, in order to recover a polymetallic solution on the one hand and a solid residue A on the other hand. Analysis of the solution shows that it contains 1.2 g / L of molybdenum, 3.2 g / L of cobalt, 2.7 g / L of vanadium and 0.02 g / L of arsenic.The calculated extraction rates of Mo and Co are therefore 2% and 26% respectively, the extraction rate of vanadium is 32% and the extraction rate of arsenic is 0.5%.

[0245] Extraction of the regenerated solid residue A with a solution containing 0.15 mol / L of citri acid

[0246] An extraction step of molybdenum and cobalt metals from the solid residue A obtained after the extraction step with sulfuric acid and ethanol is carried out on a laboratory scale: 30 g of this solid residue previously regenerated under dry air flow at 450°C for 4 hours and 75 mL of extraction solution are introduced into a flask. The extraction solution is an aqueous solution containing 0.15 mol / L of citric acid. The mixture is stirred at room temperature at 200 rpm via a magnetic bar for 6 hours. The mixture is then filtered through a sintered glass of porosity 5, in order to recover a polymetallic solution on the one hand and a solid residue on the other hand. Analysis of the solution shows that it contains 26.3 g / L of molybdenum, 4.4 g / L of cobalt, 2.3 g / L of vanadium and 0.69 g / L of arsenic.The extraction rates calculated from the Mo and Co source catalyst are therefore 57% and 53% respectively, the vanadium extraction rate is 44% and the arsenic extraction rate is 17%.

[0247] 7.6 mL of leaching solution is taken to which 2.63 g of molybdenum oxide (MoOa), 0.67 g of cobalt hydroxide (Co(OH)2), 0.60 g of phosphoric acid (H3PO4 100% pure) and 1.42 g of citric acid (100%) are added. 8 mL of impregnation solution is obtained which is impregnated onto 10 g of alumina (dry impregnation). After 16 hours of maturation at room temperature in a humid atmosphere and 2 hours of drying at 120°C, the recycled catalyst obtained B contains 21% by weight of MoOs and the molar ratios Co / Mo 0.38, P / Mo 0.3 and AC / Mo 0.4.

[0248] Extraction of the regenerated solid residue A with an aqueous solution containing 1 mol / L of acid

[0249] An extraction step of molybdenum and cobalt metals from the solid residue A obtained after the extraction step with sulfuric acid and ethanol is carried out on a laboratory scale: 30 g of this solid residue previously regenerated under dry air flow at 450°C for 4 hours and 75 mL of extraction solution are introduced into a flask. The extraction solution is an aqueous solution containing 1 mol / L of citric acid. The mixture is stirred at room temperature at 200 rpm via a magnetic bar for 6 hours. The mixture is then filtered through a sintered glass of porosity 5, in order to recover a polymetallic solution on the one hand and a solid residue C on the other hand. Analysis of the solution shows that it contains

[0250] 40.6 g / L of molybdenum, 7.2 g / L of cobalt, 3.5 g / L of vanadium and 0.74 g / L of arsenic. The extraction rates calculated from the Mo and Co source catalyst are therefore 88% and 88% respectively, the vanadium extraction rate is 66% and the arsenic extraction rate is 18%.

[0251] 7.6 mL of leaching solution is taken to which 2.47 g of molybdenum oxide (MoOs), 0.63 g of cobalt hydroxide (Co(OH)2), 0.60 g of phosphoric acid (H3PO4 100% pure) and 0.19 g of citric acid (100%) are added. 8 mL of impregnation solution is obtained which is impregnated onto 10 g of alumina (dry impregnation). After 16 hours of maturation at room temperature in a humid atmosphere and 2 hours of drying at 120°C, the recycled catalyst obtained C contains 21% by weight of MoOs and the molar ratios Co / Mo 0.38, P / Mo 0.3 and AC / Mo 0.4. The clever sequence of extraction steps and the increase in citric acid concentration thus makes it possible to significantly reduce the quantity of vanadium and increase the extraction rate of Mo and Co metals without significantly increasing that of arsenic. Catalyst C, which contains less vanadium and arsenic, has a higher level of performance than catalyst B, which contains more contaminants.

Claims

Claims 1. A process for producing a catalyst comprising at least one metal from group VIB and / or at least one metal from group VIII, optionally phosphorus and / or sulfur, and an oxide support(s), characterized in that said process comprises recycling at least a portion of the metal(s) from group VIB and / or group VIII from a source catalyst comprising at least one metal from group VIB and / or at least one metal from group VIII common with the catalyst to be produced, said source catalyst being contaminated with at least coke, vanadium and arsenic, the process comprising: - an extraction of at least a portion of the vanadium from said source catalyst by an extraction solution comprising at least sulfuric acid, to obtain a source catalyst depleted in vanadium, then - a regeneration of said vanadium-depleted source catalyst to obtain a regenerated source catalyst, then - an extraction of the group VIB metal and / or the group VIII metal from said regenerated source catalyst by an extraction solution comprising at least one organic compound having complexing properties, to obtain a solution of extracted group VIB and / or VIII metal(s), then - impregnation of the support 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 at least sulfuric acid until impregnation.

2. Method according to the preceding claim, in which the source catalyst comprises coke in a content of between 2 and 20% by weight, vanadium in a content of between 1 and 50,000 ppm by weight and arsenic in a content of between 1 and 25,000 ppm by weight, relative to the total weight of the source catalyst, said contents being expressed as an element.

3. Method according to one of the preceding claims, in which the concentration of sulfuric acid is between 0.5 and 3 mol / L.

4. Method according to one of the preceding claims, in which the extraction solution comprising at least sulfuric acid also comprises an alcohol.

5. Method according to the preceding claim, in which the alcohol in the extraction solution comprising at least sulfuric acid is chosen from at least one of the following compounds: methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2- methyl-1-propanol, tert-butanol, 1,2-ethanediol, 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol and 1,6-hexanediol.

6. Method according to one of the preceding claims, wherein in the extraction step with an extraction solution comprising at least sulfuric acid, the extraction rate of vanadium is greater than 10% by weight, the extraction rate of the group VIII metal is less than 50% by weight, the extraction rate of the group VI B metal is less than 20% by weight, the extraction rate corresponding to the mass of vanadium and metal / metals extracted in the extraction solution relative to the mass of vanadium and metal / metals initially present on the source catalyst.

7. Method according to one of the preceding claims, in which the regeneration step is carried out at a temperature between 320°C and 550°C under a flow of gas containing oxygen.

8. Method according to one of the preceding claims, in which the organic compound of the extraction solution comprising at least one organic compound having complexing properties is 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 of between 200 and 1500 g / mol), propylene glycol, glycerol, 2-butoxyethanol, 2-(2-butoxyethoxy)ethanol, 2-(2-methoxyethoxy)ethanol, triethylene glycol dimethyl ether, a crown ether, acetophenone, 2,4-pentanedione, pentanone, glucose, fructose, sucrose, sorbitol, xylitol, mannitol, y-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, 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., 9. The method of claims 1 to 8, wherein the organic compound in the extraction step with an extraction solution comprising at least one organic compound has complexing and acidic properties.

10. Method according to the preceding claim, in which the organic compound is 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 (H EDP 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., 11. Method according to one of the preceding claims, in which the organic compound of the extraction solution comprising at least one organic compound having complexing properties is chosen from formic acid, acetic acid, oxalic acid, citric acid, γ-ketovaleric acid, fructose, ethylene glycol, diethylene glycol and triethylene glycol.

12. Method according to one of the preceding claims, in which the concentration of each organic compound in the extraction solution comprising at least one organic compound having complexing properties is between 0.03 and 2 mol / L.

13. Method according to one of the preceding claims, wherein in the extraction step with an extraction solution comprising at least one organic compound having complexing properties, the extraction rate of the metal from group VIII or group VI B is respectively greater than 50% by weight and the extraction rate of arsenic is less than 30% by weight, the extraction rate corresponding to the mass of the extracted metal / metals and of the extracted arsenic in the extraction solution relative to the mass of metal / metals present and of the arsenic initially present on the source catalyst.

14. Method according to one of the preceding claims, in which the source catalyst is subjected to at least one pretreatment step before the sulfuric acid extraction step chosen from deoiling, grinding or washing with water.

15. Method according to one of the preceding claims, in which the solution of extracted metal(s) is subjected to at least one treatment step before impregnation of the support, said treatment step being chosen from a concentration, a dilution and / or a modification of the composition of the solution by addition or elimination, total or partial, of at least one compound from said solution.

16. Method according to one of the preceding claims, in which the impregnation of the support with an impregnation solution is carried out from the solution of extracted metal(s) and an addition of at least one of the metals from group VIII / VIB, and optionally phosphorus and / or organic additive(s).

17. Method according to one of the preceding claims, in which at least part of the impregnation solution is reused after impregnation of the support as a supplement to the extraction solution comprising at least one organic compound having complexing properties.

18. Method according to one of the preceding claims, in which the support on which the impregnation is carried out with the impregnation solution resulting from the solution of extracted metal(s) is pre-impregnated or post-impregnated with an impregnation solution or is a metal-depleted catalyst.

19. Method according to one of the preceding claims, wherein said impregnated substrate obtained after impregnation is subjected to a drying step, optionally to a calcination step and optionally to a sulfurization step.