Process for the sulfidation of hydrocarbon processing catalysts

Abstract

The present invention relates to a process for the sulfidation of a hydrocarbon processing catalyst, comprising: (i) at least one step of contacting the catalyst with an emulsion comprising: (ia) an aqueous phase including at least one acid; and (ib) an organic phase; and then (ii) at least one step of contacting the catalyst with a sulfur gas mixture containing hydrogen and a sulfur compound. The present invention also relates to a process for treating a spent catalyst, implementing such a sulfidation treatment after a regeneration step.

Description

Title of the invention: Sulfuration process for hydrocarbon processing catalysts

[0001] The present invention relates to a process for the sulfidation of catalysts intended for the treatment of hydrocarbons in the field of petroleum refining and petrochemicals, employing an emulsion comprising an acidic aqueous phase and an organic phase. PREVIOUS STATE OF THE ART

[0002] Hydrocarbon processing methods carried out in refineries and / or petrochemical units include a number of treatments, possibly performed in the presence of hydrogen, which are intended to modify the structure of hydrocarbon molecules and / or to remove undesirable compounds from hydrocarbon fractions, such as sulfur, nitrogen, oxygen, aromatic, and metallic compounds. Examples, by way of non-limiting agreement, include hydrocracking or hydroconversion, reforming, isomerization, alkylation, hydrogenation, dehydrogenation, and hydrotreating processes such as hydrodesulfurization, hydrodeazotation, hydrodearomatization, hydrodemetallation, and hydrodeoxygenation.

[0003] These processes employ specific catalysts, which are in the form of small particles (or catalyst grains) and comprise a porous support based on one or more refractory inorganic oxides, onto which one or more catalytically active metals are deposited. These metals most often include one or more metals from group VIII of the periodic table of elements, and / or one or more metals from group VIB.

[0004] At the end of the manufacture of the catalyst, or at the end of its regeneration in the case of a catalyst already used, the metals are in the form of metal oxides which, as such, are not active.

[0005] To enable catalysts to be active in the various hydrocarbon processing methods, it is necessary to carry out sulfidation of the catalyst, namely a treatment of it by means of sulfur compounds, in order to transform the metal oxides into mixed sulfides, which constitute the active phase of the catalyst.

[0006] This sulfidation step is particularly important, since it conditions the activity of the catalyst in its subsequent use.

[0007] Numerous sulfuration processes have been described in the prior art, such as, in particular, gas-phase sulfuration processes in which the catalyst is treated with a gaseous mixture containing sulfur (typically (in the form of hydrogen sulfide).

[0008] Thus, patent application EP 1 634 939 describes a gas-phase sulfidation process using a gas containing hydrogen sulfide (H2S) and hydrogen (H2), with an H2S / H2 molar ratio greater than 4 and a partial pressure of H2S of at least 1 kPa.

[0009] Numerous methods for improving the performance of these sulfidation processes have been described.

[0010] Thus, patent application EP 0 993 868 describes an ex-situ sulfidation process for a hydrocarbon hydroconversion catalyst, in the presence of hydrogen and at least one sulfide compound. This process is characterized in that the catalyst is brought into contact with at least one hydrocarbon compound, preferably liquid, prior to sulfidation.

[0011] Patent application EP 1 077 085 describes a sulfuration process which is characterized in that the catalyst is pre-carbonized so as to deposit in its pores a carbon compound which is largely non-leachable.

[0012] Furthermore, patent application EP 1 272 272 describes a process for the sulfidation of a catalyst containing at least one hydrogenating metal of groups VI and / or VIII and an organic additive, in which the catalyst is, in the first instance, brought into contact with an organic liquid, and then, in the second instance, brought into contact with hydrogen and a gaseous compound containing sulfur, provided that less than 40% of the sulfur present in the sulfided catalyst was supplied by the organic liquid.

[0013] The use of sulfuration auxiliaries such as, in particular, organic acids, which are deposited on the surface of the catalyst before the sulfuration step, is also known.

[0014] Thus, EP 2 295 521 describes a process for the sulfidation of a hydrocarbon processing catalyst, comprising a first step of depositing an unsaturated dicarboxylic acid of a particular formula onto the surface of the catalyst, followed by a second gas-phase sulfidation step. The acid is deposited by impregnating the catalyst with an aqueous solution containing it, followed by a drying step to remove the water.

[0015] EP application 2 295 522 describes a similar process in which a thiocarbyl acid is deposited during the first step.

[0016] Continuing its research on the sulfidation of hydrotreating catalysts, the Applicant has now discovered that it is possible to improve gas-phase sulfidation processes by treating the catalyst with a specific emulsion prior to the sulfidation step. This discovery forms the basis of the present invention. Summary of the invention

[0017] Thus, the present invention relates to a process for the sulfidation of a hydrocarbon treatment catalyst, comprising: (i) at least one step of contacting the catalyst with an emulsion comprising: (ia) an aqueous phase comprising at least one acid; and (ib) an organic phase; then (ii) at least one step of contacting the catalyst with a sulfur gas mixture containing hydrogen and a sulfur compound.

[0018] The process according to the invention makes it possible to obtain a better degree of sulfidation of the catalyst, compared to the processes of the prior art.

[0019] It also allows for a significant increase in the activity of the catalyst.

[0020] Moreover, compared to a fictitious process - not described in the prior art - which com taking a step of depositing an acid sulfuration auxiliary in aqueous solution and then a step of impregnation with a liquid hydrocarbon, the process according to the invention has been shown to make it possible to significantly reduce the undesirable phenomena of catalyst attrition.

[0021] As is known per se, catalyst particle attrition corresponds to mechanical wear of said particles due to friction between the grains or against the walls of the containers holding them, by impacts and / or crushing, particularly during the transport, handling and use of the catalyst. This phenomenon results in particle breakage and an undesirable reduction in their size, as well as the formation of "fines", i.e., unwanted dust.

[0022] The process according to the invention is suitable for the sulfidation of both new hydrotreating catalysts and used hydrotreating catalysts that have been previously regenerated. It is particularly suitable for carrying out the sulfidation of used hydrotreating catalysts that have been previously regenerated.

[0023] The present invention also relates to a process for treating a spent hydrotreating catalyst, implementing the particular sulfidation process described in this application following a regeneration step. Such a treatment process thus comprises a step of regenerating the catalyst by heat treatment in the presence of oxygen and at a temperature ranging from 350°C to 550°C, followed by the sulfidation process according to the invention.

[0024] Other objects, features, aspects and advantages of the invention will become even clearer upon reading the description and the figure in the appendix.

[0025] In what follows, and unless otherwise indicated, the bounds of a domain of values ​​are included in that domain, in particular in the expressions "included between " and "ranging from ... to ...". Furthermore, the expressions "at least one" and "at least" used in this description are respectively equivalent to the expressions "one or more" and "greater than or equal to". Finally, in a manner known in itself, a compound or group in CN is designated as a compound or group containing in its chemical structure N carbon atoms. DETAILED DESCRIPTION

[0026] The aqueous phase fia) of the emulsion The emulsion implemented in step (i) of the process according to the invention comprises an aqueous phase (ia).

[0027] This aqueous phase comprises water and one or more acids, which may be chosen from mineral and organic acids. It typically takes the form of a solution of the acid(s) in water.

[0028] The acid(s) may be present in the form of free acids or in salt form, for example in the form of alkali metal salts such as sodium and potassium salts, alkaline earth metal salts such as magnesium salts, and ammonium salts.

[0029] Any acid soluble in water at the temperature at which step (i) is carried out can be used.

[0030] Among the usable mineral acids, we can mention in particular phosphoric acid (H3PO4), metaphosphoric acid (HPO3) and pyrophosphoric acid (H4P2O7).

[0031] According to a preferred embodiment, the aqueous phase comprises one or more organic acids, preferably chosen from carboxylic acids.

[0032] The carboxylic acid(s) usable in the invention typically contain from 1 to 10 carbon atoms. They may contain, in addition to carbon, hydrogen and oxygen atoms, heteroatoms such as, in particular, sulfur and nitrogen.

[0033] Such carboxylic acids can advantageously be chosen from monocarboxylic acids, dicarboxylic acids, tricarboxylic acids, aminopolycarboxylic acids, and mixtures thereof.

[0034] Among monocarboxylic acids, one can mention in particular those of the formula R-COOH, where R designates a hydrocarbon group, saturated or unsaturated, comprising from 1 to 9 carbon atoms and optionally one or more heteroatoms such as sulfur, oxygen, and nitrogen. Examples of such acids include methanoic acid (formic acid), ethanoic acid (acetic acid), lactic acid, glycolic acid, crotonic acid, acrylic acid, thioacids such as 2-hydroxy-4-methylthiobutanoic acid, thioglycolic acid, and amino acids such as than 2-aminoethanoic acid (glycine).

[0035] Among the dicarboxylic acids, we may mention in particular malic acid, maleic acid, malonic acid, itaconic acid, oxalic acid, mesoxalic acid, fumaric acid, succinic acid, tartaric acid, glutaric acid, ketoglutaric acid, iminodiacetic acid, galactaric acid (mucinic acid), adipic acid, diglycolic acid, valeric acid and mixtures thereof.

[0036] Among the tricarboxylic acids, we can mention in particular citric acid, isocitric acid, aconitic acid, oxalosuccinic acid.

[0037] Among the aminopolycarboxylic acids, ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), and diethylenetriaminepentaacetic acid (DTPA) can be used in particular.

[0038] The carboxylic acid(s) are preferably chosen from glycolic acid, thioglycolic acid, maleic acid, citric acid, and mixtures thereof.

[0039] According to a particularly preferred embodiment, the aqueous phase contains citric acid.

[0040] Preferably, the aqueous phase contains the acid(s) in a content of 5 to 50% by weight, more preferably 15 to 30% by weight, relative to the weight of the aqueous phase.

[0041] This content is expressed on the basis of the free, unsalted acid form.

[0042] Moreover, the acid(s) advantageously represent 3 to 30% by weight, preferably 5 to 20% by weight, relative to the total weight of the emulsion.

[0043] This content is expressed on the basis of the free, unsalted acid form.

[0044] The aqueous phase advantageously has a pH within the range of 1 to 7, preferably 1.5 to 3.

[0045] The aqueous phase preferably represents 40 to 70% by volume, relative to the total volume of the emulsion, preferably 50 to 60% by volume.

[0046] The organic phase (ib) of the emulsion The emulsion implemented in step (i) of the process according to comprises an organic phase (ib).

[0047] By "organic phase" is meant any non-aqueous medium having a solubility in water at ambient temperature (25°C) and atmospheric pressure (760 mm Hg) of less than 1% by weight, and preferably less than 0.5% by weight.

[0048] Preferably, the organic phase is liquid at room temperature and atmospheric pressure.

[0049] The organic phase advantageously comprises one or more oils, preferably chosen from compounds and mixtures of compounds comprising at least one chain having at least 8 carbon atoms. The oil(s) may in particular be chosen from vegetable oils, animal oils, oils mineral oils, synthetic oils and their mixtures.

[0050] Examples of vegetable oils include castor oil, sunflower oil, peanut oil, soybean oil, rapeseed oil, coconut oil, corn oil, palm oil, linseed oil, and safflower oil.

[0051] Used cooking oils can also be mentioned, which may include vegetable oils and / or animal oils.

[0052] Suitable mineral oils are in particular chosen from hydrocarbons and mixtures of liquid hydrocarbons obtained from petroleum distillation, such as in particular and without limitation: fuel and / or combustible fractions such as gasoline, jet fuel, naphtha, diesel, and fuel oil fractions; lubricating oil fractions such as, for example, an oil marketed under the name "150 Neutral"; solvent fractions such as those known under the English name "white spirits".

[0053] Preferred mineral oils are selected from gas oil fractions (including in particular atmospheric distillation gas oils and vacuum distillation gas oils) and solvent fractions consisting of hydrocarbons selected from C8 to CM paraffinic hydrocarbons, C8 to Ci4 cycloparaffinic hydrocarbons, aromatic hydrocarbons, and mixtures thereof.

[0054] These hydrocarbon mixtures may, where appropriate, have undergone one or more hydrotreatments, for example hydrodesulfurization, isomerization,....

[0055] Examples of synthetic oils include poly(alpha-olefins) such as polydecenes and polyisobutenes; hydrocarbons and mixtures of hydrocarbons obtained by synthesis, such as by a Fischer-Tropsch synthesis process or by hydrotreating vegetable oils; trans-sterilized vegetable oils.

[0056] According to a preferred embodiment, the organic phase comprises one or more mineral oils and / or one or more vegetable oils as described above.

[0057] The organic phase may also include one or more solid fats at room temperature such as, for example, waxes.

[0058] Examples of waxes that can be used in the present invention include waxes of animal origin such as beeswax; vegetable waxes such as sunflower wax; mineral waxes, for example, paraffin waxes, petroleum jelly waxes; synthetic waxes such as polyethylene waxes, waxes from a Fischer-Tropsch synthesis; and mixtures thereof.

[0059] The organic phase preferably represents 30 to 60% by volume, relative to the total volume of the emulsion, preferably 40 to 50% by volume.

[0060] Sulphur compounds (optional) According to a preferred embodiment, the emulsion also comprises one or several sulfur compounds, which can be chosen from organic sulfur compounds and mineral sulfur compounds.

[0061] When the emulsion contains one or more mineral sulfur compounds, this or these sulfur compounds are advantageously present in the aqueous phase of the emulsion. Thus, according to a preferred embodiment of the invention, the aqueous phase (ia) contains one or more sulfur compounds, preferably chosen from among the mineral sulfur compounds.

[0062] Mineral sulfur compounds can be selected in particular from among thiosulfates such as sodium thiosulfate, potassium thiosulfate, ammonium thiosulfate; metabisulfites such as, for example, sodium metabisulfite, potassium metabisulfite, ammonium metabisulfite; and elemental sulfur (the latter being advantageously in suspension in the aqueous phase).

[0063] When the emulsion contains one or more organic sulfur compounds, this or these sulfur compounds are advantageously present in the organic phase of the emulsion. Thus, according to a preferred embodiment of the invention, the organic phase (ib) contains one or more sulfur compounds, preferably chosen from among the organic sulfur compounds.

[0064] Organic sulfur compounds may be selected in particular from polysulfides, mercaptans, thiols, thiophenes, sulfoxides.

[0065] Polysulfides are in particular selected from compounds of formula R-Sn-R', in which: - n is an integer in the range from 3 to 20, preferably from 3 to 8 and more particularly from 3 to 7, and - R and R', whether identical or different, represent organic radicals containing from 1 to 150 carbon atoms, preferably from 10 to 60 carbon atoms and more particularly from 15 to 30 carbon atoms, R' also being able to represent hydrogen. These radicals can be saturated or unsaturated, linear or branched, or cyclic, and can be chosen from the group consisting of alkyl radicals, alkenyl radicals, aryl radicals, alkylaryl radicals and arylalkyl radicals, these radicals being able to contain at least one heteroatom.

[0066] As an example of polysulfide, one can cite di-tert-butyl-polysulfide of formula (CH3)3C-S4-C(CH3)3.

[0067] Mercaptans are in particular selected from compounds of the formula R-SH, in which R represents an organic radical containing from 1 to 150 carbon atoms, preferably 10 to 60 carbon atoms and more particularly 8 to 30 carbon atoms. This radical may be saturated or unsaturated, linear or branched, or cyclic, and may be selected from the group consisting of alkyl radicals, alkenyl radicals, aryl radicals, alkylaryl radicals and arylalkyl radicals. which may include at least one heteroatom.

[0068] As an example of a mercaptan, 1-nonanethiol with the formula CH3(CH2)7 may be cited. ch2-sh.

[0069] The sulfoxides are in particular selected from compounds of the formula R-SO-R', in which R and R', identical or different, represent organic radicals containing from 1 to 150 carbon atoms, preferably from 10 to 60 carbon atoms and more particularly from 15 to 30 carbon atoms, R' being able to also represent hydrogen. These radicals may be saturated or unsaturated, linear or branched, or cyclic, and may be selected from the group consisting of alkyl radicals, alkenyl radicals, aryl radicals, alkylaryl radicals and arylalkyl radicals, these radicals being able to comprise at least one heteroatom.

[0070] As an example of sulfoxide, we can cite dodecylmethyl sulfoxide of formula CH3(CH2)10CH2-SO-CH3.

[0071] It is of course possible to use mixtures of sulfur-containing organic compounds as described above.

[0072] Generally speaking, the sulfur compound(s), when present, advantageously represent 4 to 12% by weight, preferably 6 to 10% by weight, relative to the total weight of the emulsion.

[0073] According to a preferred embodiment, the organic phase of the emulsion contains one or more organic sulfur compounds as described above, more preferably chosen from polysulfides, mercaptans, sulfoxides, and mixtures of these compounds, and even more preferably from polysulfides.

[0074] In this embodiment, the organic sulfur compound(s) advantageously represent 10 to 40% by weight, preferably 15 to 25% by weight, relative to the total weight of the organic phase.

[0075] The emulsion The emulsion implemented in step (i) of the process according to the invention can be a direct emulsion (i.e. of the oil-in-water type, the organic phase being dispersed in the aqueous phase) or an indirect emulsion (i.e. of the water-in-oil type, the aqueous phase being dispersed in the organic phase).

[0076] Preferably, it is a direct emulsion, that is to say that the organic phase is dispersed in the aqueous phase.

[0077] According to a preferred embodiment, the emulsion further comprises one or more surfactant(s).

[0078] The surfactant(s) may advantageously be chosen from anionic surfactants, non-ionic surfactants, amphoteric surfactants, and mixtures thereof, preferably from non-ionic surfactants.

[0079] Examples of suitable non-ionic surfactants include: - alkyl(C8-C24)oxyalkylened phenols; - alcohols in the C8 to C40 range, saturated or unsaturated, linear or branched, oxyalkylated or glycerolated, and comprising one or two fatty chains; - esters of C8 to C30 acids, saturated or unsaturated, linear or branched, and of polyols or polyethylene glycols; - esters of C8 to C30 acids, saturated or unsaturated, linear or branched, and of sorbitol, preferably oxygenated; - fatty acid and sucrose esters, - alkyl(C8-C3O)(poly)glucosides and alkenyl(C8-C3O)(poly)glucosides, possibly oxyalkylated (0 to 10 oxyalkylene motifs) and comprising 1 to 15 glucose motifs; alkyl (C8-C3O)(poly)glucoside esters, - oxyethylenated vegetable oils, saturated or unsaturated; - ethylene oxide and / or propylene oxide condensates; - and their mixtures.

[0080] The oxyalkylated motifs are more particularly oxyethylened, oxy-propylened motifs, or their combination, preferably oxyethylened.

[0081] The number of moles of ethylene oxide and / or propylene preferably ranges from 1 to 250, more particularly from 2 to 100; better from 2 to 50; the number of moles of glycerol ranges in particular from 1 to 50, better from 1 to 10.

[0082] The non-ionic surfactant(s) are more preferably chosen from among the C8 to C24 oxyethylenated alcohols comprising from 1 to 40 moles of ethylene oxide, preferably from 2 to 20 moles of ethylene oxide.

[0083] The surfactant(s) are preferably present in a total content of 0.1 to 5% by weight, better 0.2 to 2.5% by weight, and better still 0.5 to 1.5% by weight, relative to the total weight of the emulsion.

[0084] The step (it Step (i) consists of bringing the catalyst particles into contact with the emulsion described above.

[0085] Preferably, the volume of emulsion used in this step is greater than or equal to at least 80% of the total pore volume of the catalyst. More preferably, the volume of emulsion used is in the range of 100 to 140% of the total pore volume of the catalyst, and even better, 100 to 120% of the total pore volume of the catalyst.

[0086] As is known per se, the pore volume of a catalyst is determined by nitrogen adsorption. The pore volume measured by nitrogen adsorption was determined by the Barrett-Joyner-Halenda (BJH) model. The nitrogen adsorption-desorption isotherm according to the BJH model is described in the publication "The Journal of the American Society", 73, 373, (1951) by E.P. Barrett, L.G. Joyner, and P.P. Halenda.

[0087] Generally, step (i) is carried out by impregnating the catalyst with the emulsion, such that the emulsion penetrates the porosity of the catalyst. Any known means of enabling a liquid to penetrate porous particles can be used for this purpose.

[0088] One can, for example, proceed by soaking and stirring the catalyst in the emulsion.

[0089] Preferably, this step is carried out by agitating the catalyst particles and spraying the emulsion onto them.

[0090] This step can be carried out continuously or discontinuously, preferably continuously.

[0091] In a continuous process, step (i) can, for example, be carried out in one of the following ways: - by spraying the emulsion onto the catalyst in a mixing chamber located upstream of the sulfidation unit; - by spraying the emulsion onto the catalyst in the feed system of the sulfidation unit, for example while the catalyst passes through a vibrating feeder or a helical screw, with the dual action of mixing the emulsions with the catalyst and feeding the sulfidation unit(s).

[0092] Step (i) can have a variable duration, generally ranging from a few minutes to a few hours. Preferably, this contact lasts approximately 1 hour.

[0093] It can be carried out at a pressure ranging from atmospheric pressure to 5 bars, preferably at atmospheric pressure, and at a preferred temperature ranging from ambient temperature to 100°C.

[0094] According to a preferred embodiment, step (i) is carried out at a temperature ranging from 25°C to 100°C, preferably from 40 to 90°C and even better from 50 to 80°C.

[0095] The sulfuration step (ii) The process according to the invention also includes at least one step (ii), during which the catalyst from step (i) - therefore on which the emulsion is deposited - is brought into contact with a sulfur gas mixture which contains hydrogen and a sulfur compound.

[0096] Advantageously, the sulfur compound is hydrogen sulfide (H2S), or a sulfur compound capable of releasing hydrogen sulfide by hydrogenolysis under the operating conditions of this step. Such sulfur compounds may be chosen, for example, from elemental sulfur, CS2, organic sulfur compounds such as mercaptans, sulfides, disulfides, polysulfides, thiols, thiophenes, and sulfoxides.

[0097] Preferably, the sulfide compound is hydrogen sulfide.

[0098] One can proceed, for example, in the manner described in patent application EP 1,634,939.

[0099] Thus, according to a preferred embodiment of step (ii), the catalyst is brought into contact with a sulfur gas mixture containing hydrogen and hydrogen sulfide.

[0100] Hydrogen sulfide advantageously represents from 5 to 70% by volume of the hydrogen sulfide + hydrogen mixture, preferably from 10 to 60% by volume.

[0101] The sulfur gas mixture may, in addition to hydrogen and the sulfur compound, also comprise one or more other gases, such as inert dilution gases, for example nitrogen. Such additional gases may, for example, represent from 5 to 80% by volume of said gas mixture.

[0102] Step (ii) is advantageously carried out at a temperature ranging from 150 to 500°C, preferably from 200 to 350°C.

[0103] Preferably, the temperature varies during the duration of step (ii). Thus, it is possible to proceed in at least two steps, a first step of gradual temperature increase, followed by a second step of stabilization at a temperature within the range of 200 to 350°C.

[0104] Step (ii) is preferably carried out in continuous mode, in a sulfidation unit containing one or more reactors in which the catalyst particles circulate in contact with the sulfur gas mixture.

[0105] Step (ii) can be carried out in a fixed bed or a moving bed, for example in a fluidized or bubbling bed, or in a rotary kiln. In the case of a moving bed, the sulfur gas mixture can flow co-currently or counter-currently to the catalyst bed, preferably counter-currently.

[0106] The amount of sulfur incorporated into the catalyst during this step depends on the amount of active metals present on its surface. Preferably, the amount of sulfur incorporated represents 50 to 200%, preferably 80 to 120%, and more preferably 90 to 110% of the stoichiometric amount of sulfur required for the active metals to be entirely in the form of metal sulfides.

[0107] For example, in the case of a catalyst whose active metals are cobalt and molybdenum, the sulfide forms corresponding to a stoichiometry of 100% can be assimilated to CoS and MoS2 respectively.

[0108] The process In the process according to the present invention, step (ii) is carried out after step (i). It can be carried out directly after step (i), or be separated from it by one or more intermediate step(s).

[0109] Thus, the process according to the invention may also include, between steps (i) and (ii), a catalyst drying step, which may be carried out at a temperature ranging from 80°C to 350°C, preferably from 100°C to 200°C, in open air or in the presence of a gaseous flow of air, inert gas such as nitrogen, or any other suitable gas.

[0110] According to a preferred embodiment, the process does not include an intermediate step, in particular no drying step. In other words, step (i) is directly followed by step (ii) and the catalyst onto which the emulsion is deposited is directly sulfided.

[0111] The sulfuration process according to the invention may also further comprise one or more additional steps, which may be carried out before and / or after said steps (i) and (ii) described above.

[0112] Thus, step (ii) can advantageously be followed by a cooling step, during which the catalyst is brought back to ambient temperature, or to a temperature close to ambient temperature. This cooling, generally carried out gradually, can be performed in the presence of the sulfur gas mixture, or any other suitable gas, for example hydrogen, an inert gas such as nitrogen, oxygen, or a mixture of such gases, or different gas mixtures used successively.

[0113] Thus, a first phase of cooling the catalyst in a sulfur gas mixture can be carried out, followed by a second phase of cooling under an inert gas, for example nitrogen.

[0114] According to a preferred embodiment of the invention, the process further comprises, after step (ii), a catalyst passivation step, which is preferably an oxidative passivation.

[0115] This oxidative passivation consists of bringing the catalyst into contact with oxygen or a gaseous mixture containing oxygen. Preferably, a gaseous mixture containing less than 30% oxygen is used. This gaseous mixture can, in particular, be air. The contact of the catalyst with the oxygen-containing gas can take place in several stages, with a progressive increase in the oxygen content over time.

[0116] The passivation step is preferably carried out at a temperature of 150°C or less, for a duration generally of less than 24 hours. It can in particular be carried out simultaneously with the catalyst cooling step carried out at the end of step (ii).

[0117] In the case of an ex situ sulfidation process, passivation has the particular advantage of reducing the pyrophoric tendency of the sulfide phases present on the surface of the catalyst, and therefore of allowing easy transfer or storage of the latter, for example in metal drums or other types of containers.

[0118] The process according to the present invention can be carried out in situ, that is to say directly within the unit in which the catalyst is used.

[0119] According to a preferred embodiment, it is carried out ex situ, that is to say after de- loading the catalyst out of the unit.

[0120] Hvdrotreatment catalysts The process according to the present invention makes it possible to sulfide any catalyst intended for the treatment of hydrocarbons, in the fields of refining and petrochemicals.

[0121] These catalysts are in the form of porous solid particles, which comprise at least one active metal such as, in particular, a hydrogenating metal, deposited on a support based on one or more refractory mineral oxides.

[0122] By hydrogenating metal is meant a metal of groups VIII and VIB of the periodic table of elements.

[0123] Preferably, the catalysts treated using the process according to the invention are catalysts containing at least one metal from Group VIII of the periodic table of elements, such as, for example, cobalt, nickel, or iron, combined with at least one metal from Group VIB, such as, for example, molybdenum, tungsten, or chromium. The content of the Group VIII metal(s) is generally between 0.1 and 10% by weight relative to the total weight of the catalyst, and the content of the Group VIB metal(s) is generally between 1 and 20% by weight relative to the total weight of the catalyst.

[0124] The hydrogenating metal(s) is / are deposited on a support based on one or more refractory mineral oxides such as, in particular, aluminas, silicas, silica-aluminas, zeolites, zirconias, titanium and boron oxides, and mixtures of such oxides.

[0125] The process according to the invention is particularly suitable for the sulfidation of hydrotreating catalysts comprising active metals deposited on a non-zeolitic support selected from aluminas, silicas, and silica-aluminas. More preferably, said non-zeolitic support contains at least 30% by weight of alumina, and preferably at least 50% by weight.

[0126] The process according to the invention is particularly suitable for the sulfidation of catalysts containing the metal associations CoMo, NiMo, NiW, NiCoMo, deposited on alumina-based supports.

[0127] The catalysts treated using the process according to the invention may, in addition to the hydrogenating metal(s), contain any suitable additional ingredients. They may thus contain, for example, and without limitation, one or more halogenated, borated, or phosphorus compounds, or one or more elements selected from those of groups IIIB, IVB, and VB of the periodic table of elements.

[0128] The process according to the present invention is particularly suitable for the sulfidation of catalysts containing no organic additives. Thus, it is particularly suitable for the sulfidation of catalysts for which the difference between the loss on ignition at 500°C and the loss on ignition at 150°C is less than or equal to 2% by weight, relative to the weight of the initial catalyst.

[0129] As is well known to those skilled in the art, the expression "loss on ignition" (or LOI, from the English "loss on ignition") refers to the loss of mass resulting from the heating of a material, due to the release of volatile substances.

[0130] A catalyst containing organic matter, such as an organic additive, exhibits a significant loss on ignition at 500°C, resulting from the decomposition of this organic matter. Furthermore, due to their large specific surface area and hygroscopic nature, catalysts can absorb a considerable amount of water, including from atmospheric humidity, resulting in a loss on ignition at 150°C ranging from 5 to 10% by weight. Therefore, to determine whether a catalyst contains an organic additive, the difference between the loss on ignition at 500°C and the loss on ignition at 150°C must be considered.

[0131] Hydrocarbon processing catalysts are generally in the form of small solid particles such as beads, more or less cylindrical particles, or extrudates. They have a specific surface area, measured by the BET method, generally between 100 and 300 m² / g, a pore volume, determined by nitrogen adsorption, ranging from 0.25 to 1 ml / g, and an average pore diameter, determined by nitrogen adsorption, ranging from 7 to 20 nm.

[0132] Once treated using the process according to the present invention, the catalyst is ready for use, and can advantageously be used directly in the hydrocarbon treatment process for which it is intended.

[0133] It is also possible to carry out a second sulfidation treatment of the catalyst, in particular in situ, immediately before use of the catalyst. This may in particular be a sulfidation treatment carried out in the presence of hydrogen by passing a liquid phase containing sulfur through the catalyst, typically a sulfur-containing hydrocarbon cut and / or enriched in sulfur-containing hydrocarbons, such as, for example, a distillate possibly with added dhnetyl disulfide.

[0134] Thus, the process according to the invention can be used as a pre-sulfurization process, in order to precondition the catalyst, to reduce the intensity and duration of the final sulfidation treatment carried out in situ, thus saving time, and to increase the efficiency of the hydrocarbon treatment process.

[0135] The catalysts obtained by means of the process according to the invention can be used in any industrial process employing a sulfur catalyst. They are particularly intended for hydrocarbon processing methods such as petroleum fractions, hydrocarbons produced from natural gas, coal, and oxygenated or non-oxygenated hydrocarbons of plant origin.

[0136] By way of non-limiting examples, hydrocracking or hydroconversion, reforming, isomerization, alkylation, hydrogenation, dehydrogenation and so-called hydrotreating processes such as hydrodesulfurization, hydrodeazotation, hydrodearomatization, hydrodemetallation, hydrodeoxygenation.

[0137] The process according to the present invention is particularly suitable for the sulfidation of catalysts intended for hydrotreating petroleum fractions, and in particular for the hydrodesulfurization process.

[0138] The process according to the invention is suitable for the sulfidation of both new catalysts and used catalysts that have been previously regenerated.

[0139] According to a preferred embodiment, the catalyst is a spent hydrotreating catalyst that has been previously regenerated.

[0140] A spent catalyst is a catalyst which, as a result of its use in a hydrotreating reactor, has been deactivated in particular due to the deposition on its surface of coke, i.e. a mixture of heavy hydrocarbons, carbon residues, metallic impurities.

[0141] The regeneration of spent catalysts is a well-known process which consists of carrying out the combustion of the coke, by heating the catalyst to a high temperature in the presence of a gas containing oxygen.

[0142] The process for treating a spent catalyst Thus, the invention also relates to a method for treating a spent catalyst, which includes: - a heat treatment step of the catalyst in the presence of oxygen and at a temperature ranging from 350°C to 550°C, then; - the sulfidation of the sulfidation catalyst by means of the process as described above.

[0143] The heat treatment step consists of heating the spent catalyst to a temperature ranging from 350°C to 550°C, in the presence of oxygen. Its purpose is to eliminate the coke present on the surface of the catalyst by burning it.

[0144] Temperature control within the catalyst is essential during this step. The temperature must be high enough to allow for the most complete combustion possible of the coke. However, it must not exceed 550°C, even locally, as this would damage the catalyst, for example by degrading its porosity.

[0145] Preferably, this heat treatment step is carried out at a temperature less than or equal to 530°C, and preferably less than or equal to 520°C.

[0146] According to a preferred embodiment, the heat treatment step is carried out, in whole or in part, at a temperature in the range of 450 to 550°C.

[0147] The temperature within the catalyst can be controlled, in a manner known per se, for example by means of thermocouples appropriately arranged within the mass of the catalyst.

[0148] This step is carried out in the presence of oxygen, for example by means of a gas stream containing oxygen. This gas may consist, for example, of air, pure or mixed with additional oxygen or an inert gas, so as to increase or decrease the oxygen content of the air. This gas may also consist of a mixture of oxygen and an inert gas such as nitrogen, or other gas mixtures comprising oxygen.

[0149] The oxygen content of the gas is preferably controlled in order to better control the combustion temperature. This content may be fixed, or on the contrary, vary over time. The gas flow rate is also controlled in order to control the combustion.

[0150] This heat treatment step may include several phases, carried out at different temperatures and / or in the presence of varying amounts of oxygen.

[0151] The total duration of this step generally depends on the quantity of catalyst to be treated, its composition, the amount of coke present on its surface, and the operating conditions (temperature, oxygen content). This duration is shorter the higher the temperature. It is generally between 0.1 and 20 hours, preferably between 0.2 and 10 hours.

[0152] The following examples are given purely to illustrate the present invention.

[0153] EXAMPLES The following examples were produced using a spent conventional NiMo-on-alumina hydrotreating catalyst from a hydrodeoxygenation unit. This catalyst was regenerated by thermal treatment in the presence of an oxygenated gas in a rotary louvre unit. This regenerated catalyst (designated catalyst C) contains 4 wt% NiO and 18 wt% MoO3 supported on gamma alumina. Its pore volume is 0.52 ml / g.

[0154] Comparative Example 1: A 100g sample of catalyst C was treated as follows: - a single step (ii) of contacting the catalyst with a gaseous mixture consisting of an H2S / H2 / N2 mixture with a partial pressure of H2S of 0.3, a partial pressure of H2 of 0.25 and a partial pressure of N2 of 0.45. This step was carried out at atmospheric pressure, in a vertical reactor, with the downward gas flow passing through the catalyst bed at a volumetric hourly gas velocity (WH) of 300 h1. The temperature was increased by 5°C / min up to 250°C, then a 2h plateau at this temperature was observed.

[0155] A sample of Sla sulfide catalyst was thus obtained.

[0156] Comparative Example 2: A 100g sample of catalyst C was treated as follows: - a first step (i) of contacting the catalyst with an organic solution consisting of 14.3g of rapeseed oil (corresponding to 30% of the pore volume of the catalyst), by impregnating the catalyst with the organic solution at a temperature of 60°C for a duration of 1h, then - a second step (ii) identical to that described in Example 1 above.

[0157] A sample of sulfide catalyst S2 was thus obtained.

[0158] Comparative Example 3: A 100g sample of catalyst C was treated as follows: - a first step (i) of contacting the catalyst with 30ml of a citric acid solution in water having a concentration of 27% by weight of acid (corresponding to 60% of the porous volume of the catalyst), by impregnating the catalyst with this solution at a temperature of 60°C for a duration of 1h, then - a second step (ii) identical to that described in Example 1 above.

[0159] A sample of sulfide catalyst S3 was thus obtained.

[0160] Comparative Example 4: A 100g sample of catalyst C was treated as follows: - a first step (i) of contacting the catalyst with 30ml of a citric acid solution in water having a concentration of 27% by weight of acid (corresponding to 60% of the porous volume of the catalyst), by impregnating the catalyst with this solution at a temperature of 60°C for a duration of 1h, then - a second step (i)' of contacting the catalyst with an organic solution consisting of 14.3g of rapeseed oil, 4.7g of di-tert-butyl polysulfide and 0.19g of a surfactant consisting of a trimethylnonyl polyethylene glycol ether, marketed under the name Tergitol TMX 100X® (corresponding to 40% of the pore volume of the catalyst), by impregnating the catalyst with the organic solution at a temperature of 60°C for a duration of 1h, then - a third step (ii) identical to that described in Example 1 above.

[0161] A sample of sulfide catalyst S4 was thus obtained.

[0162] Example 5 according to the invention: A 100g sample of catalyst C was treated as follows: - a first step (i) of bringing the catalyst into contact with an emulsion consisting of: an aqueous phase consisting of 30 ml of a citric acid solution in water having a concentration of 27% by weight of acid (corresponding to 60% of the pore volume of the catalyst), and an organic phase consisting of 19g of rapeseed oil and 0.19g of a surfactant consisting of a trimethylnonyl polyethylene glycol ether, marketed under the name Tergitol TMX 100X® (corresponding to 40% of the pore volume of the catalyst), by impregnating the catalyst with this emulsion at a temperature of 60°C for a duration of Ih then - a second step (ii) identical to that described in Example 1 above.

[0163] A sample of sulfide catalyst S5 was thus obtained.

[0164] Example 6 according to the invention: A 100g sample of catalyst C was treated as follows: - a first step (i) of bringing the catalyst into contact with an emulsion consisting of: an aqueous phase consisting of 30 ml of a citric acid solution in water having a concentration of 27% by weight of acid (corresponding to 60% of the pore volume of the catalyst), and an organic phase consisting of 14.3g of rapeseed oil, 4.7g of di-tert-butyl-polysulfide and 0.19g of a surfactant consisting of a trimethylnonyl polyethylene glycol ether, marketed under the name Tergitol TMX 100X® (corresponding to 40% of the pore volume of the catalyst), by impregnating the catalyst with this emulsion at a temperature of 60°C for a duration of Ih then - a second step (ii) identical to that described in Example 1 above.

[0165] A sample of sulfide catalyst S6 was thus obtained.

[0166] Example 7: Performance evaluation of SI sulfide catalysts at S5 For each of the catalysts described SI to S5, the following properties were evaluated:

[0167] - Determination of the catalyst's sulfidation rate: The sulfur content was measured using an organic elemental analyzer, which allows the determination of the contents of C, H, N, O, S. The sulfuration rate (STI) is defined as the ratio between the measured sulfur content of the catalyst, expressed on a dry basis after correction for loss on ignition at 500°C (quantity of volatile compounds such as water, evaporated at 500°C), and the theoretical sulfur content (ST0) of the catalyst, corresponding to the sulfided metals in stoichiometric quantities, i.e. in the form of MoS2 and NiS sulfides. The degree of sulfidation is defined by the following formula: sn(%) = ioo*[s / (i-^g)] / sro

[0168] - Determination of catalyst attrition: This parameter was determined on 50 g samples of catalyst, according to the The principle described in ASTM D-4058 involves placing a catalyst sample in a cylindrical drum equipped with a lifting device (a sheet metal plate welded to the inner wall of the drum) on its generatrix. After closing the drum with a lid, the assembly is rotated for 30 minutes. The weight loss of the catalyst sample is then measured by sieving it through a #20 (0.85 mm) sieve to remove the fines produced. The weight percentage of fines produced is then calculated.

[0169] This test allows for the simulation of successive falls of catalyst particles, which generate breakage and fines.

[0170] - Determination of hydrodesulfurization (HDS) activity: The test was carried out in a pilot unit by hydrodesulfurization of a feedstock consisting of diesel fuel obtained from the direct distillation of crude oil, known as "straight run," with a sulfur content of 1.514% by weight. The operating conditions were as follows: pressure of 5 MPa (50 bar), H2 / feedstock ratio of 300, hourly gas volumetric velocity WH = 1.5h', temperature of 360°C. The sulfur content of the feed was measured at the unit outlet using a UV fluorescence analyzer.

[0171] The apparent constants of the desulfurization reaction were calculated according to the following formula El: (The) with Kv = apparent reaction constant; a = reaction order (considered equal to 1.2); S = sulfur content of the effluents; So = sulfur content of the feedstock WH = hourly volumetric velocity of the liquid charge.

[0172] The performance of each sample was evaluated against that of a reference catalyst. For this purpose, the relative volume activity (RVA) was calculated according to the following formula E2: x 100 (E2)

[0173] As a reference, the Kv value of 100 was assigned to the corresponding new catalyst, activated in situ (in the unit) by means of a mixture of diesel and dimethyl disulfide.

[0174]

[0175] - Determination of hydrodeoxygenation activity (fHDO): The test was carried out in a pilot unit by hydrodeoxygenation of a feedstock consisting of rapeseed oil. The operating conditions were as follows: pressure of 2 MPa (20 bar), H2 / feedstock ratio of 1600, hourly gas volumetric velocity WH = 0.5h temperature of 295°C. The oxygen content of the feed was measured at the unit inlet and outlet.

[0176] The apparent constants of the deoxygenation reaction were calculated according to the following formula El': k,= W ra(E1) with Kv = apparent reaction constant; a = reaction order (considered equal to 1.4); O = oxygen content of the effluents O0 = oxygen content of the load WH = hourly volumetric velocity of the liquid charge.

[0177] The performance of each sample was evaluated against that of a reference catalyst. For this purpose, the relative volume activity (RVA) was calculated according to the following formula E2': x 100 (E2')

[0178] As a reference, the Kv value of 100 was assigned to the corresponding new catalyst, activated in situ (in the unit) by means of a mixture of hydrotreated vegetable oil and dimethyl disulfide.

[0179]

[0180] The results obtained are detailed in Table 1 below.

[0181] [Tables 1] Catalyst Sulfuration STI (rate in %) Attrition (%) HD S Activity (%) HDO Activity (%) SI 95 0.5 92 93 S2 92 0.3 98 99 S3 99 3.5 96 102 S4 98 4.0 103 110 S5 100 0.3 110 116 S6 100 0.3 117 126

[0182]

[0183] These results show that the samples of catalysts S5 and S6 sulfided according to the process according to the invention exhibit superior properties to the samples SI, S2, S3 and S4 sulfided by means of processes not according to the invention.

[0184] These results show that the process according to the invention gives the catalyst superior properties in terms of sulfidation rate, attrition reduction and activity in various hydrotreating reactions.

Claims

Demands

1. A process for the sulfidation of a hydrocarbon processing catalyst, comprising: (i) at least one step of contacting the catalyst with an emulsion comprising: (ia) an aqueous phase comprising at least one acid; and (ib) an organic phase; then (ii) at least one step of contacting the catalyst with a sulfur gas mixture containing hydrogen and a sulfur compound.

2. A process according to the preceding claim, characterized in that said aqueous phase (ia) comprises one or more acids, in the form of free acids or in salified form, selected from mineral acids and organic acids, preferably from carboxylic organic acids, and more preferably from monocarboxylic acids, dicarboxylic acids, tricarboxylic acids, aminopolycarboxylic acids and mixtures thereof.

3. A process according to the preceding claim, characterized in that the carboxylic acid(s) are selected from maleic acid, glycolic acid, thioglycolic acid, citric acid, and mixtures thereof, and more preferably the aqueous phase contains citric acid.

4. A process according to any one of the preceding claims, characterized in that the acid(s) represent from 3 to 30% by weight, preferably from 5 to 20% by weight, relative to the total weight of the emulsion, this content being expressed on the basis of the free acid form.

5. A process according to any one of the preceding claims, characterized in that the aqueous phase (ia) represents 40 to 70% by volume, relative to the total volume of the emulsion, preferably 50 to 60% by volume.

6. A process according to any one of the preceding claims, characterized in that the organic phase (ib) comprises one or more oils, preferably selected from compounds and mixtures of compounds comprising at least one chain having at least 8 carbon atoms, more preferably selected from vegetable oils, animal oils, mineral oils, synthetic oils and mixtures thereof.

7. A process according to the preceding claim, characterized in that the organic phase (ib) comprises one or more mineral oils, of

8.

9. preference chosen from fuel and / or combustible fractions such as gasoline, jet fuel, naphtha, diesel, fuel oil fractions; lubricating oil fractions; solvent fractions. A process according to any one of claims 6 and 7, characterized in that the organic phase (ib) comprises one or more vegetable oils, preferably selected from castor oil, sunflower oil, peanut oil, soybean oil, rapeseed oil, coconut oil, corn oil, palm oil, linseed oil and safflower oil. A process according to any one of the preceding claims, characterized in that the organic phase (ib) also comprises one or more sulfur compounds, preferably selected from organic sulfur compounds and more preferably from polysulfides, mercaptans, sulfoxides, and mixtures of these compounds, and more preferably from: - polysulfides selected from compounds of formula R-Sn-R', in which: n is an integer in the range from 3 to 20, preferably from 3 to 8 and more particularly from 3 to 7, and R and R' identical or different represent organic radicals containing from 1 to 150 carbon atoms, preferably from 10 to 60 carbon atoms and more particularly from 15 to 30 carbon atoms, R' being able to also represent hydrogen; these radicals being able to be saturated or unsaturated, linear or branched, or cyclic, and being able to be chosen from the group consisting of alkyl radicals, alkenyl radicals, aryl radicals, alkylaryl radicals and arylalkyl radicals, these radicals being able to include at least one heteroatom; - mercaptans selected from compounds of formula R-SH, in which R represents an organic radical containing from 1 to 150 carbon atoms, preferably 10 to 60 carbon atoms and more particularly from 8 to 30 carbon atoms; this radical being able to be saturated or unsaturated, linear or branched, or cyclic, and being able to be selected from the group consisting of alkyl radicals, alkenyl radicals, aryl radicals, alkylaryl radicals and arylalkyl radicals, these radicals being able to include at least one heteroatom; - sulfoxides chosen from compounds of formula R-SO-R', in which R and R', identical or different, represent gold radicals organics containing from 1 to 150 carbon atoms, preferably from 10 to 60 carbon atoms and more particularly from 15 to 30 carbon atoms, R' being able to also represent hydrogen; these radicals being able to be saturated or unsaturated, linear or branched, or cyclic, and being able to be chosen from the group consisting of alkyl radicals, alkenyl radicals, aryl radicals, alkylaryl radicals and arylalkyl radicals, these radicals being able to include at least one heteroatom; - and mixtures of these compounds.

10. A process according to any one of the preceding claims, characterized in that the aqueous phase (ia) also comprises one or more sulfur compounds, preferably selected from mineral sulfur compounds and more preferably from thiosulfates such as sodium thiosulfate, potassium thiosulfate, ammonium thiosulfate; metabisulfites such as sodium metabisulfite, potassium metabisulfite, ammonium metabisulfite; and elemental sulfur.

11. A process according to any one of the preceding claims, characterized in that the emulsion further comprises one or more surfactant(s), preferably selected from anionic surfactants, non-ionic surfactants, amphoteric surfactants, and mixtures thereof, more preferably from non-ionic surfactants.

12. A process according to the preceding claim, characterized in that the emulsion comprises one or more non-ionic surfactants selected from: - oxyalkylated alkyl(C8-C24)phenols; - C8 to C40 alcohols, saturated or unsaturated, linear or branched, oxyalkylated or glycerolated, and comprising one or two fatty chains; - esters of C8 to C30 acids, saturated or unsaturated, linear or branched, and of polyols or polyethylene glycols; - esters of C8 to C30 acids, saturated or unsaturated, linear or branched, and of sorbitol, preferably oxyethylated; - esters of fatty acids and sucrose, - alkyl(C8-C30)(poly)glucosides and alkenyl(C8-C30)(poly)glucosides, possibly oxyalkylated (0 to 10 oxy-alkylene motifs) and comprising 1 to 15 glucose motifs; esters of alkyl (C8-C30)(poly)glucosides, - oxyethylenated vegetable oils, saturated or unsaturated; - ethylene oxide and / or propylene oxide condensates; - and mixtures thereof; and preferably among C8 to C24 oxyethylenated alcohols comprising 1 to 40 moles of ethylene oxide, preferably 2 to 20 moles of ethylene oxide.

13. A process according to any one of claims 11 and 12, characterized in that the surfactant(s) are present in a total content of 0.1 to 5% by weight, better 0.2 to 2.5% by weight, and better still 0.5 to 1.5% by weight, relative to the total weight of the emulsion.

14. A process according to any one of the preceding claims, characterized in that the volume of emulsion used in step (i) is greater than or equal to at least 80% of the total pore volume of the catalyst, preferably within the range of 100 to 140% of the total pore volume of the catalyst, and even better of 100 to 120% of the total pore volume of the catalyst.

15. A method according to any one of the preceding claims, characterized in that step (i) is carried out at a temperature ranging from 25°C to 100°C, preferably from 40 to 90°C and even better from 50 to 80°C.

16. A process according to any one of the preceding claims, characterized in that step (ii) is carried out by contacting the catalyst with a sulfur gas mixture containing hydrogen and hydrogen sulfide.

17. A process for treating a spent catalyst, characterized in that it comprises: - a heat treatment step of the catalyst in the presence of oxygen at a temperature ranging from 350°C to 550°C, then; - the sulfidation of the catalyst by means of the process as defined in any one of the preceding claims.