Method for recovering consumed and regenerated catalysts from the hydrodesulfurization method of gasolines

Abstract

The present invention relates to a method for recovering at least partially consumed catalyst resulting from a hydrodesulfurization method of a sulfur-containing olefinic gasoline cut, wherein the at least partially consumed catalyst is derived from a new catalyst from a metal from group VIIl, a metal from group VIb, and an oxide support, and the method comprises: a) a step of regenerating the at least partially consumed catalyst in an oxygen-containing gas stream at a temperature of 350°C to 550°C; b) a step of contacting the regenerated catalyst with an impregnation solution containing a compound containing a metal from group VIb, wherein the molar ratio of the metal from group VIb added to the metal from group VIb already present in the regenerated catalyst is 0.15 to 2.5 mol / mol; c) a step of performing a drying step at a temperature of less than 200°C, and the invention relates to the use of the regenerated catalyst in such a hydrodesulfurization method.

Description

Technology Field

[0001] The present invention relates to a method for recovering a catalyst used in a hydrodesulfurization method of gasoline cut and to the use of the recovered catalyst in such a method. Background Technology

[0002] Sulfur is an element naturally present in crude oil and, therefore, exists in gasoline and diesel fuels unless removed during refining. However, sulfur in gasoline hinders the efficiency of emission reduction systems (catalytic converters) and contributes to air pollution. To prevent environmental pollution, all countries are consequently adopting increasingly stringent sulfur specifications, which, for example, are 10 ppm (weight) of sulfur in commercial gasolines in Europe, China, the United States, and Japan. The issue of reducing sulfur content essentially focuses on gasolines obtained by catalytic (FCC, fluid catalytic cracking) or non-catalytic (coking, bisbraking, steam cracking) decomposition of major sulfur precursors in gasoline pools.

[0003] One solution well known to those skilled in the art for reducing sulfur content consists of performing hydrotreatment (or hydrodesulfurization) of hydrocarbon cuts (and particularly catalytic cracking gasolines) in the presence of hydrogen and a heterogeneous catalyst. However, this method exhibits a major disadvantage in that it causes a very significant drop in octane rating if the catalyst used is not sufficiently selective. This reduction in octane rating is particularly associated with the hydrogenation of olefins present in this type of gasoline, accompanied by hydrodesulfurization.

[0004] Unlike other hydrotreatment methods, particularly those for gas-oil type feedstocks, the hydrodesulfurization of gasolines must therefore address a dual incompatible constraint: providing extreme hydrodesulfurization of gasolines while limiting the hydrogenation of existing unsaturated compounds.

[0005] The most widely used approach to address the aforementioned dual problem consists of using a method in which the sequence of unit stages enables maximizing hydrodesulfurization while simultaneously limiting the hydrogenation of olefins. Thus, the most recent methods, such as the Prime G+ (trademark) method, make it possible to desulfurize olefin-rich cracked gasoline while limiting the hydrogenation of mono-olefins and consequently the loss of octane and the resulting high hydrogen consumption. Such methods are described, for example, in patent applications EP 1 077 247 and EP 1 174 485.

[0006] Therefore, while achieving the desired reaction selectivity (the ratio of hydrodesulfurization to the hydrogenation of olefins) may be partly attributed to the choice of method, in all cases, the use of an inherently selective catalyst system is often a very major factor. Generally, the catalysts used in this type of application are sulfide-type catalysts containing elements from Group VIb (Cr, Mo, W) and elements from Group VIII (Fe, Ru, Os, Co, Rh, Ir, Pd, Ni, Pt). Thus, in patent US 5 985 136, 0.5 x 10 -4 Up to 3 x 10 -4 g of MoO3 / m 2 It is claimed that a catalyst exhibiting a surface concentration of [substance] makes it possible to achieve high selectivity for 33% hydrogenation (HOO) of olefins in hydrodesulfurization (93% hydrodesulfurization (HDS)). Additionally, according to patents US 4 140 626 and US 4 774 220, it may be advantageous to add a dopant (alkali metal, alkaline earth metal) to a conventional sulfide phase (CoMoS) intended to limit the hydrogenation of olefins. Literature describing selective hydrodesulfurization catalysts, US 8 637 423 and EP 1 892 039, is also known in the art.

[0007] During the use of hydrogenation catalysts for the hydrotreatment of oil cuts, the catalyst experiences a decrease in activity due to the deposition of coke and / or sulfur-based or heterogeneous compounds. Replacement becomes essential after a certain period. In particular, stricter sulfur specifications for fuels lead to an increased frequency of catalyst replacement, resulting in higher catalyst-related costs and increased catalyst consumption.

[0008] To overcome these drawbacks, the regeneration (gradual calcination) of catalysts or consumed residues for the hydrodesulfurization of middle fractions (gas oil) is an economically and ecologically advantageous method because it enables the reuse of these catalysts in industrial units rather than landfilling or recycling (recovering metals). However, regenerated catalysts are generally less active than the starting solids.

[0009] To overcome the lack of hydrodesulfurization activity of the regenerated catalyst, it is possible to apply an additional "recovery" treatment. The recovery method consists of re-impregnating the regenerated catalyst with a solution containing a metal precursor in the presence of organic or inorganic additives. Such "recovery" methods are well known to those skilled in the art in the field of middle distillates. For example, many patents such as US 7 906 447, US 8 722 558, US 7 956 000, US 7 820 579, or also CN102463127 provide different methods for carrying out the recovery of catalysts for the hydrotreatment of middle distillates. Literature US 2017 / 036202 describes an increase in activity in a diesel hydrotreatment method when metals and phosphorus from Group VIb are added to the regenerated catalyst. Compared to catalysts for the selective hydrodesulfurization of gasolines, catalysts for the hydrodesulfurization of middle fractions containing high metal content undergo significant sintering during use and regeneration. Therefore, recovery treatment focuses on the dissolution and redistribution of metal phases to restore dispersion and, consequently, activity close to that of new catalysts. Currently, methods for recovering hydrotreatment catalysts have been developed to restore only the hydrodesulfurization activity of the catalyst for the hydrodesulfurization of middle fractions.

[0010] Catalysts for the selective hydrodesulfurization of cracked gasolines exhibit recovery issues different from those for the hydrotreatment of gas oils, particularly due to the need to maintain the selective properties of the catalyst for reactions involving the hydrodesulfurization and hydrogenation of olefins. This is because, generally, an increase in selectivity is more desirable in the field of gasolines than an increase or maintenance of activity. Therefore, there is a significant advantage in developing specific recovery methods for catalysts for the selective hydrodesulfurization of gasolines.

[0011] Such a recovery method is described in Patent No. CN105642312 for a consumed catalyst for the selective hydrodesulfurization of FCC gasolines. This combined method uses one or more metal additives containing at least one element selected from Na, K, Mg, Ca, Cu, and Zn, as well as organic agents; and uses heat treatment in an atmosphere with controlled oxygen content.

[0012] Therefore, there is currently great interest in manufacturers, regenerators, and purifiers for catalysts that, in order to recover hydrodesulfurization catalysts, particularly for catalysts for the hydrodesulfurization of gasoline cuts, exhibit maintained or even improved catalyst performance quality, especially in terms of catalytic activity and / or selectivity in hydrodesulfurization, and thus, once employed, enable the production of gasoline with low sulfur content without a significant reduction in octane rating.

[0013] Accordingly, the present invention relates to a "recovery" method suitable for a selective hydrodesulfurization catalyst, the purpose of which is the complete restoration of the hydrodesulfurization activity of the catalyst and the maintenance, in fact even improvement, of the selectivity of the new catalyst.

[0014] The present invention relates to a method for recovering at least partially consumed catalyst resulting from a hydrodesulfurization method of a sulfur-containing olefinic gasoline cut, wherein the at least partially consumed catalyst is derived from a novel catalyst comprising at least one metal from Group VIII, at least one metal from Group VIb, an oxide support, and optionally phosphorus, and the method comprises

[0015] a) a step of regenerating the above-mentioned at least partially consumed catalyst in an oxygen-containing gas stream at a temperature of 350°C to 550°C to obtain a regenerated catalyst,

[0016] b) a step in which the regenerated catalyst comes into contact with at least one impregnation solution containing at least one compound comprising a metal from group VIb, wherein the molar ratio of the added metal from group VIb per metal from group VIb already present in the regenerated catalyst is 0.15 to 2.5 mol / mol, said at least one impregnation solution.

[0017] c) The drying step includes a step performed at a temperature of less than 200°C to obtain a recovered catalyst.

[0018] This is because it has been observed that the recovery method according to the present invention makes it possible to obtain a recovered catalyst exhibiting improved catalytic activity compared to using the same new catalyst, and surprisingly leads to an improvement in selectivity in the selective hydrodesulfurization method of gasolines. Without being bound by any theory, it is believed that the changes in the active phase caused by the recovery of the regenerated catalyst lead to better selectivity for the hydrodesulfurization reaction of the active sites, and make it possible to compensate for the reduction in the number of these sites and thus maintain the activity of the catalyst.

[0019] According to one alternative form, in step b), the impregnation solution further contains a compound comprising a metal from Group VIII; and the molar ratio of the added metal from Group VIII per metal from Group VIII already present in the regenerated catalyst is 0.1 to 2.5 mol / mol.

[0020] According to one alternative embodiment, in step b), the impregnation solution further contains phosphorus; and the molar ratio of added phosphorus per metal from group VIb already present in the regenerated catalyst is 0.1 to 2.5 mol / mol.

[0021] According to one alternative form, in step b), the impregnation solution further contains an organic compound containing oxygen and / or nitrogen and / or sulfur; and the molar ratio of the organic compound added per metal from group VIb already present in the regenerated catalyst is 0.01 to 5 mol / mol.

[0022] According to one alternative form, the organic compound containing oxygen and / or nitrogen and / or sulfur is selected from compounds comprising one or more chemical functional groups selected from carboxylic acids, alcohols, thiols, thioethers, sulfones, sulfoxides, ethers, aldehydes, ketones, esters, carbonates, amines, nitriles, imides, oximes, ureas, or amide functional groups, or also from compounds comprising furan rings or sugars.

[0023] According to one alternative form, the organic compound containing oxygen and / or nitrogen and / or sulfur is γ-valerolactone, 2-acetylbutyrolactone, triethylene glycol, diethylene glycol, ethylene glycol, ethylenediaminetetraacetic acid, maleic acid, malonic acid, citric acid, gluconic acid, di(C1-C4 alkyl) succinate, glucose, fructose, sucrose, sorbitol, xylitol, γ-ketovaleric acid, dimethylformamide, 1-methyl-2-pyrrolidinone, propylene carbonate, 2-methoxyethyl 3-oxobutanoate, visine, trisine, 2-furaldehyde, 5-hydroxymethylfurfural, 2-acetylfuran, 5-methyl-2-furaldehyde, ascorbic acid, butyl lactate, ethyl It is selected from 3-hydroxybutanoate, ethyl 3-ethoxypropanoate, 2-ethoxyethyl acetate, 2-butoxyethyl acetate, 2-hydroxyethyl acrylate, 1-vinyl-2-pyrrolidinone, 1,3-dimethyl-2-imidazolidinone, 1-(2-hydroxyethyl)-2-pyrrolidinone, 1-(2-hydroxyethyl)-2,5-pyrrolidinone, 5-methyl-2(3H)-furanone, 1-methyl-2-piperidinone and 4-aminobutanoic acid.

[0024] According to one alternative form, a de-oiling step is preceded before the regeneration step a), which includes contacting a stream of inert gas with at least partially consumed catalyst at a temperature of 300°C to 400°C.

[0025] According to one alternative form, at the end of the drying step c), the calcination step d) is performed at a temperature of 200°C to 600°C.

[0026] According to one alternative form, the new catalyst has a metal content from group VIb of 1% to 20% by weight of the oxide of the metal from group VIb relative to the total weight of the catalyst.

[0027] According to one alternative form, the new catalyst has a content of metal from Group VIII of 0.1% to 10% by weight of oxide of the metal from Group VIII relative to the total weight of the catalyst.

[0028] According to one alternative form, the new catalyst has a phosphorus content of 0.3 wt% to 10 wt%, expressed as P2O5, relative to the total weight of the catalyst, and the phosphorus / (metal from group VIb) molar ratio in the catalyst is 0.1 to 0.7.

[0029] According to one alternative form, the oxide support of the new catalyst is selected from alumina, silica, silica-alumina, or titanium or magnesium oxides used alone or as a mixture with alumina or silica-alumina.

[0030] According to one alternative form, the new catalyst features a specific surface area of ​​20 to 200 m² / g, preferably 30 to 180 m² / g.

[0031] The present invention also relates to a hydrodesulfurization method for a sulfur-containing olefinic gasoline cut in which the gasoline cut, hydrogen, and a catalyst recovered according to the method of the present invention come into contact, wherein the hydrodesulfurization method comprises a temperature of 200°C to 400°C, a total pressure of 1 to 3 MPa, and 1 to 10 h -1 It is carried out at an hourly space velocity defined as the flow rate per volume of feedstock relative to the volume of the catalyst, and at a hydrogen / gasoline feedstock ratio per volume of 100 to 1200 Sl / l.

[0032] According to one alternative form, the recovered catalyst undergoes a sulfidation step before or during the hydrodesulfurization method.

[0033] According to one alternative form, the hydrodesulfurization method is carried out in a catalyst bed of a fixed-bed type reactor comprising several catalyst beds; and at least one other catalyst bed upstream or downstream of the catalyst bed containing the recovered catalyst in the direction of circulation of the feedstock comprises at least partially a new catalyst and / or a regenerated catalyst.

[0034] According to one alternative form, the hydrodesulfurization method is carried out in a series of at least two reactors of the fixed bed type or ebulate bed type; at least one of the reactors contains a regenerated catalyst, while another reactor contains a new catalyst or a regenerated catalyst, or a mixture of a regenerated catalyst and a new and / or regenerated catalyst, in any order, with or without removing at least some of the H2S from the effluent originating from the first reactor before treating the effluent in the second reactor.

[0035] Next, groups of chemical elements are given according to the CAS classification (CRC Handbook of Chemistry and Physics, published by CRC Press, editor DR Lide, 81st edition, 2000-2001). For example, Group VIII according to the CAS classification corresponds to the metals from columns 8, 9, and 10 according to the new IUPAC classification. Specific details for implementing the invention

[0036] The recovered catalyst obtained in the method according to the present invention is at least partially consumed catalyst and is derived from a new catalyst, which is used in a hydrodesulfurization method of a sulfur-containing olefinic gasoline cut under the conditions described below for a predetermined period of time, exhibits significantly lower activity than the new catalyst, and requires replacement.

[0037] A new catalyst used in the hydrodesulfurization method of sulfur-containing olefinic gasoline cuts is known to those skilled in the art. It comprises at least one metal from Group VIII, at least one metal from Group VIb, an oxide support, and optionally phosphorus and / or an organic compound as described below. According to other alternative forms, the new catalyst does not contain phosphorus.

[0038] The preparation of a new catalyst is known and generally comprises a step of impregnating a metal from Group VIII and Group VIb and optionally phosphorus and / or organic compounds into an oxide support, followed by a drying operation, and then an optional calcination step that enables obtaining an active phase in the form of the oxide. Before use in a hydrodesulfurization method of sulfur-containing olefinic gasoline cuts, the new catalyst generally undergoes sulfidation to form an active entity as described below.

[0039] According to another embodiment of the present invention, the new catalyst does not undergo calcination during its manufacture, that is, the impregnated catalyst precursor does not undergo a heat treatment step at a temperature greater than 200°C under an inert atmosphere or an oxygen-containing atmosphere in the presence or absence of water.

[0040] According to another alternative embodiment of the present invention, the new catalyst undergoes a calcination step during its manufacture, that is, the impregnated catalyst precursor undergoes a heat treatment step at a temperature of 250°C to 1000°C and preferably 200°C to 750°C for a period of typically 15 minutes to 10 hours in the presence or absence of water, under an inert atmosphere or an oxygen-containing atmosphere.

[0041] The metal from Group VIb present in the active phase of the new catalyst is preferentially selected from molybdenum and tungsten. The metal from Group VIII present in the active phase of the new catalyst is preferentially selected from cobalt, nickel, and mixtures of these two elements. The active phase of the new catalyst is preferably selected from the group formed by combinations of nickel-molybdenum, cobalt-molybdenum, and nickel-cobalt-molybdenum elements, and very preferably the active phase consists of cobalt and molybdenum.

[0042] The content of the metal from Group VIII is 0.1% to 10% by weight, preferably 0.6% to 8% by weight, preferably 2% to 7% by weight, very preferably 2% to 6% by weight, and more preferably 2.5% to 6% by weight of the oxide of the said metal from Group VIII with respect to the total weight of the new catalyst.

[0043] The content of the metal from group VIb is 1% to 20% by weight, preferably 2% to 18% by weight, and very preferably 3% to 16% by weight of the oxide of the said metal from group VIb with respect to the total weight of the new catalyst.

[0044] The molar ratio of metal from group VIII to metal from group VIb of the new catalyst is generally 0.1 to 0.8, preferably 0.2 to 0.6.

[0045] In addition, the new catalyst exhibits a density of metal from Group VIb, expressed as the number of atoms of the metal per unit area of ​​the catalyst, which is 0.5 to 30 atoms of metal from Group VIb per n m² of the catalyst, preferably 2 to 25 atoms, and more preferably 3 to 15 atoms. The density of metal from Group VIb, expressed as the number of atoms of metal from Group VIb per unit area of ​​the catalyst (number of atoms of metal from Group VIb per n m² of the catalyst), is calculated, for example, from the following relationship:

[0046]

[0047] X = Weight % of metal from group VIb;

[0048] N A = 6.022 x 10 23 Avogadro's number equivalent to;

[0049] S = Specific surface area of ​​the catalyst measured according to standard ASTM D3663 (m² / g);

[0050] M M = Molar mass of metal from group VIb (e.g., 95.94 g / mol for molybdenum).

[0051] For example, if the catalyst contains 20 wt% molybdenum oxide MoO3 (i.e., 13.33 wt% Mo) and has a specific surface area of ​​100 m² / g, the density d(Mo) is as follows:

[0052]

[0053] Catalysts for the hydrodesulfurization of gasoline generally differ from catalysts for the hydrodesulfurization of gas-oil type middle fractions due to a higher density of metals from Group VIb. This is because, even though catalysts for gasoline hydrodesulfurization generally have a lower content of metals from Group VIb than those for middle fractions, the specific surface areas of gasoline catalysts are much higher than those of middle fraction catalysts (generally 200 m 2 This is because it results in a higher density of metals from group VIb (exceeding / g).

[0054] Optionally, the new catalyst may additionally contain a phosphorus content of generally 0.3 wt% to 10 wt% of P2O5, preferably 0.5 wt% to 5 wt% of P2O5, and very preferably 1 wt% to 3 wt% of P2O5, based on the total weight of the new catalyst. For example, the phosphorus present in the new catalysts is combined with metals from Group VIb and optionally also with metals from Group VIII in the form of heteropolyanions.

[0055] In addition, the phosphorus / (metal from group VIb) molar ratio is generally 0.1 to 0.7, preferably 0.2 to 0.6, when phosphorus is present.

[0056] Preferably, the new catalyst is characterized by a specific surface of 5 to 400 m² / g, preferably 10 to 250 m² / g, preferably 20 to 200 m² / g, and very preferably 30 to 180 m² / g. The specific surface in the present invention is, Rouquerol F., Rouquerol J. Singh K., Adsorption by Powders & Porous Solids:Principle, Methodology and Applications As described in the work by Academic Press, 1999, it is determined by the BET method according to the standard ASTM D3663, for example by the Micromeritics™ brand Autopore III™ model device.

[0057] The pore volume of the new catalyst is generally 0.4 cm³ / g to 1.3 cm³ / g, preferably 0.6 cm³ / g to 1.1 cm³ / g. The total pore volume is measured by the mercury porosiometric method according to standard ASTM D4284 with a wetting angle of 140°, as described in the same work.

[0058] The tapped bulk density (TBD) of the new catalyst is generally 0.4 to 0.7 g / ml, preferably 0.45 to 0.69 g / ml. TBD measurement is performed by introducing the catalyst into a measuring cylinder of a predetermined volume and then tapping it by vibration until a constant volume is obtained. The bulk density of the tapped product is calculated by comparing the mass introduced with the volume occupied after tapping.

[0059] The new catalyst may be in the form of cylindrical or multi-lobed (triple-lobed, quadruple-lobed, etc.) extruders having a small diameter, or spheres.

[0060] The oxide support of the new catalyst is a porous solid generally selected from the group consisting of alumina, silica, silica-alumina, and titanium and magnesium oxides used alone or in a mixture with alumina or silica-alumina. It is preferably selected from the group consisting of silica, the family of transition aluminas, and silica-aluminas; most preferably, the oxide support is essentially composed of at least one transition alumina, i.e., it contains at least 51 wt%, preferably at least 60 wt%, most preferably at least 80 wt%, and actually even at least 90 wt% of transition alumina. Preferably, it consists solely of transition alumina. Preferably, the oxide support of the new catalyst is a "high temperature" transition alumina containing theta-, delta-, kappa-, or alpha-phase alumina alone or as a mixture, and containing an amount of gamma-, kai-, or eta-phase alumina of less than 20%.

[0061] The new catalyst may also additionally include at least one organic compound containing oxygen and / or nitrogen and / or sulfur prior to sulfidation. Such additives are described later.

[0062] During the hydrogenation process, coke and sulfur originating from feedstocks such as silicon, arsenic, or chlorine, as well as other contaminants, are formed and / or deposited on the catalyst, converting the new catalyst into at least partially consumed catalyst.

[0063] Accordingly, the catalyst that is at least partially consumed consists of an active phase and an oxide support formed from at least one metal from group VIb and at least one metal from group VIII and optionally phosphorus from a new catalyst, as well as carbon, sulfur and optionally other contaminants originating from the feedstock, such as silicon, arsenic and chlorine.

[0064] The content of metals from Group VIb, metals from Group VIII, and phosphorus in new, at least partially consumed, regenerated, or recovered catalysts is expressed as oxides after correction for losses upon ignition of the catalyst sample in a muffle furnace at 550°C for 2 hours. Losses upon ignition are due to the loss of moisture, carbon, sulfur, and / or other contaminants. This is determined according to ASTM D7348.

[0065] The content of metals from Group VIb, metals from Group VIII, and optionally phosphorus in at least partially consumed catalyst is substantially the same as the content of the new catalyst from which it originates.

[0066] It is understood that the catalyst that has been at least partially consumed comes from a hydrodesulfurization method of a sulfur-containing olefinic gasoline cut performed under the conditions described below, and does not undergo heat treatment under air or oxygen-containing gas at a temperature greater than 200°C. It may also undergo de-oiling.

[0067] It should be noted that in this patent application, the terms "coke" or "carbon" refer to a hydrocarbon-based material that undergoes cyclization and condensation, has an appearance similar to graphite, and is deposited on the surface of a catalyst during use.

[0068] At least partially consumed catalyst contains carbon, in particular, in an amount of generally 2% by weight or more, preferably 2% to 10% by weight, and more preferably 2.2% to 6% by weight, relative to the total weight of at least partially consumed catalyst. This carbon content is measured by elemental analysis according to ASTM D5373.

[0069] At least partially consumed catalyst contains sulfur in an amount of 1% to 8% by weight, preferably 1% to 6.0% by weight, and particularly preferably 2% to 5% by weight, relative to the total weight of at least partially consumed catalyst. This residual sulfur content in at least partially consumed catalyst is measured by elemental analysis according to ASTM D5373.

[0070] Optionally, the catalyst that has been at least partially consumed may additionally exhibit low levels of contaminants, such as silicon, arsenic, or chlorine, which originate from the feedstock treated by the new catalyst from which it is derived.

[0071] Preferably, the silicon content (except for that which may be present in the new catalyst) is less than 2 weight percent with respect to the total weight of at least partially consumed catalyst, and very preferably less than 1 weight percent.

[0072] Preferably, the arsenic content is less than 2000 ppm by weight with respect to the total weight of at least partially consumed catalyst, and very preferably less than 500 ppm by weight.

[0073] Preferably, the chlorine content is less than 2000 ppm by weight with respect to the total weight of at least partially consumed catalyst, and very preferably less than 500 ppm by weight.

[0074] Play (step a)

[0075] A method for regenerating at least partially consumed catalyst according to the present invention comprises a step of removing coke and sulfur (regeneration step). This is because, according to step a) of the method according to the present invention, at least partially consumed catalyst is regenerated in an oxygen-containing gas stream at a temperature of 350°C to 550°C to obtain a regenerated catalyst.

[0076] Even if this is possible, regeneration is preferably not performed by maintaining the catalyst charged in the hydrogen treatment reactor (regeneration in place). Preferably, at least partially consumed catalyst is therefore extracted from the reactor and sent to a regeneration plant where regeneration (regeneration elsewhere) is performed.

[0077] Preferably, a degreasing step precedes the regeneration step a). The degreasing step generally involves contacting the at least partially consumed catalyst with a stream of inert gas (i.e., essentially oxygen-free) at a temperature of 300°C to 400°C, preferably 300°C to 350°C, for example, in a nitrogen atmosphere. In terms of flow rate per unit volume of catalyst, the inert gas flow rate is 5 to 150 Sl.l for 3 to 7 hours. -1 .h -1 am.

[0078] In an alternative form, the deoiling step can be performed by light hydrocarbons, steam treatment, or any other similar method.

[0079] The above de-oiling step enables the removal of soluble hydrocarbons and thus release the porosity of at least partially consumed catalyst necessary for recovery.

[0080] The regeneration step a) is generally performed in an oxygen-containing gas stream, generally in air. The water content is generally 0 wt% to 50 wt%. In terms of the flow rate per unit volume of at least partially consumed catalyst, the gas flow rate is preferably 20 to 2000 Sl.l. -1 .h -1 , more preferably 30 to 1000 Sl.l -1 .h -1 And particularly preferably 40 to 500 Sl.l -1 .h -1 The regeneration period is preferably 2 hours or more, more preferably 2.5 hours or more, and particularly preferably 3 hours or more. Regeneration of at least partially consumed catalyst is generally carried out at a temperature of 350°C to 550°C, preferably 360°C to 500°C.

[0081] Accordingly, the regenerated catalyst consists of an active phase and an oxide support formed from at least one metal from group VIb and at least one metal from group VIII and optionally phosphorus from the new catalyst, and also residual carbon, residual sulfur and optionally other contaminants originating from the feedstock, such as silicon, arsenic and chlorine.

[0082] The content of metals from Group VIb, metals from Group VIII, and optionally phosphorus in the regenerated catalyst is substantially the same as the content of the partially consumed catalyst and the content of the new catalyst from which it is derived.

[0083] The regenerated catalyst obtained in the regeneration step contains residual carbon in an amount of preferably less than 2% by weight, preferably 0.1% to 1.9% by weight, preferably 0.1% to 1.5% by weight, and particularly preferably 0.1% to 1.0% by weight, based on the total weight of the regenerated catalyst. The regenerated catalyst may also not contain residual carbon.

[0084] It should be noted that in this patent application, the term "residual carbon" refers to carbon (coke) remaining in the regenerated catalyst after the regeneration of at least partially consumed catalyst. The content of such residual carbon in the regenerated catalyst is measured by elemental analysis according to ASTM D5373.

[0085] The regenerated catalyst obtained in the regeneration step contains residual sulfur (before selective sulfidation) in an amount of less than 5% by weight, preferably 0.1% to 4.9% by weight, preferably 0.1% to 2.0% by weight, and particularly preferably 0.2% to 0.8% by weight, based on the total weight of the regenerated catalyst. The regenerated catalyst may also not contain residual sulfur.

[0086] The residual sulfur content in the regenerated catalyst is measured by elemental analysis according to ASTM D5373.

[0087] Playback (step b)

[0088] The recovery method according to the present invention includes a recovery step b) after a regeneration step a), wherein the recovered catalyst is brought into contact with at least one impregnation solution containing at least one compound containing a metal from group VIb, and the molar ratio of the added metal from group VIb to the metal from group VIb already present in the recovered catalyst is 0.15 to 2.5 mol / mol, preferably 0.2 to 2.0 mol / mol, more preferably 0.3 to 1.0 mol / mol.

[0089] This is because, during the use of the catalyst in the hydrodesulfurization method of gasoline, the pores of the support become blocked over time, and the active phase containing metals becomes increasingly inaccessible. A decrease in catalyst activity is observed that is not fully restored even after regeneration. To overcome the lack of hydrodesulfurization activity, it is possible to re-impregnate the catalyst with a solution containing a compound containing a metal from Group VIb and, optionally, a compound containing a metal and / or phosphorus from Group VIII, in order to limit the decline in activity and, surprisingly, increase selectivity.

[0090] According to the first alternative form, the recovery step b) may also include contacting the regenerated catalyst with an impregnation solution containing a compound containing a metal from group VIb as well as a compound containing a metal from group VIII.

[0091] In this case, the molar ratio of the added metal from Group VIII to the metal from Group VIII already present in the regenerated catalyst is 0.1 to 2.5 mol / mol, preferably 0.1 to 2.0 mol / mol, more preferably 0.1 to 1.0 mol / mol.

[0092] According to the preferred alternative form of this first alternative form, the impregnation solution contains not only solvent(s) but also compound(s) containing metals from group VIb and compound(s) containing metals from group VIII.

[0093] The metal introduced from Group VIb is preferentially selected from molybdenum and tungsten. The metal introduced from Group VIII is preferentially selected from cobalt, nickel, and mixtures of these two elements. Preferably, combinations of nickel-molybdenum, cobalt-molybdenum, and nickel-cobalt-molybdenum elements, and very preferably a combination of cobalt-molybdenum, are selected.

[0094] For example, among the sources of molybdenum, oxides and hydroxides, molybdic acid and its salts, in particular ammonium molybdate, ammonium heptmolybdate, and phosphomolybdic acid (H3PMo 12 O 40) and ammonium salts such as its salts, and optionally silicomolybdic acid (H4SiMo 12 O 40) and its salts may be used. The source of molybdenum may also be, for example, Keggin, lacunary Keggin, substituted Keggin, or any heteropolycompound of the Dawson, Anderson, or Strandberg type. Preferably, molybdenum trioxide and Keggin, lacunary Keggin, substituted Keggin, and Strandberg type heteropolycompounds are used.

[0095] Tungsten precursors that can be used are also well known to those skilled in the art. For example, among sources of tungsten are oxides and hydroxides, tungstic acids and their salts, in particular ammonium salts such as ammonium tungstate, ammonium metatungstate, phosphotungstic acids and their salts, and optionally silicotungstic acid (H4SiW). 12 O 40 ) and salts thereof may be used. The source of tungsten may also be, for example, Keggin, lacunary Keggin, substituted Keggin, or any heteropolycompound of the Dawson type. Preferably, oxides and ammonium salts, such as ammonium metatungstate or heteropolyanions of the Keggin, lacunary Keggin, or substituted Keggin type are used.

[0096] Cobalt precursors that can be used are advantageously selected from, for example, oxides, hydroxides, hydroxycarbonates, carbonates, and nitrates. Preferably, cobalt hydroxide and cobalt carbonate are used.

[0097] Nickel precursors that can be used are advantageously selected from, for example, oxides, hydroxides, hydroxycarbonates, carbonates, and nitrates. Preferably, nickel hydroxide and nickel hydroxycarbonate are used.

[0098] According to a second alternative form, the recovery step b) may also include contacting the regenerated catalyst with a compound containing a metal from group VIb and optionally a compound containing a metal from group VIII, as well as with an impregnation solution containing phosphorus.

[0099] In this case, the molar ratio of phosphorus added per metal from group VIb already present in the regenerated catalyst is 0.1 to 2.5 mol / mol, preferably 0.1 to 2.0 mol / mol, more preferably 0.1 to 1.0 mol / mol.

[0100] According to a preferred alternative form of this second alternative, the impregnation solution contains not only solvent(s) but also compound(s) containing metals from Group VIb and compound(s) containing metals from Group VIII and preferably phosphorus in the form of phosphoric acid.

[0101] A preferred phosphorus precursor is orthophosphoric acid H3PO4, but its salts and esters, such as ammonium phosphate, are also suitable. Phosphorus can also be introduced simultaneously with element(s) from Group VIb in the form of Keggin, lacunary Keggin, substituted Keggin, or Strandberg-type heteropolyanions.

[0102] Step b) of contacting the regenerated catalyst with an impregnation solution containing a compound containing a metal from Group VIb and optionally a compound containing a metal and / or phosphorus from Group VIII can be performed by slurry impregnation, by excess impregnation, by dry impregnation, or by any other means known to those skilled in the art.

[0103] Equilibrium (or excess) impregnation is achieved by immersing the support or catalyst in a solution volume (often significantly) larger than the pore volume of the support or catalyst while maintaining agitation of the system to improve exchange between the solution and the support or catalyst. Equilibrium is finally achieved after the diffusion of different entities into the pores of the support or catalyst. Control of the amount of deposited element is provided by a prior measurement of an adsorption isotherm that relates the concentration of the element to be deposited contained in the solution to the amount of the element deposited on the solid phase in equilibrium with this solution.

[0104] Dry impregnation consists of introducing an impregnation solution in a volume equal to the pore volume of the support or catalyst, for a portion thereof. Dry impregnation makes it possible to deposit all metals and additives contained in the impregnation solution onto a given support or catalyst.

[0105] Step b) can be performed using an impregnation solution, advantageously by one or more excess impregnations of the solution, or preferably by one or more dry impregnations, and very preferably by a single dry impregnation of the regenerated catalyst.

[0106] According to a third alternative form, recovery step b) may also include contacting the regenerated catalyst with an impregnation solution containing a compound containing a metal from Group VIb and optionally a compound containing a metal from Group VIII and / or phosphorus, as well as an organic compound containing oxygen and / or nitrogen and / or sulfur. The function of the additive or organic compound is to increase catalytic activity compared to a catalyst without the additive. The organic compound is preferentially impregnated into the catalyst after dissolution in an aqueous or non-aqueous solution.

[0107] In this case, the molar ratio of the organic compound added to the metal from group VIb already present in the regenerated catalyst is 0.01 to 5 mol / mol, preferably 0.05 to 3 mol / mol, in a preferred manner 0.05 to 2 mol / mol, and very preferably 0.1 to 1.5 mol / mol.

[0108] When multiple organic compounds are present, different molar ratios are applied to each of the present organic compounds.

[0109] According to a preferred alternative form of this third alternative, the impregnation solution contains not only solvent(s) but also compound(s) containing metals from group VIb, compound(s) containing metals from group VIII, preferably phosphorus in the form of phosphoric acid, and organic compound(s).

[0110] Generally, the organic compound is selected from compounds comprising one or more chemical functional groups selected from carboxylic acids, alcohols, thiols, thioethers, sulfones, sulfoxides, ethers, aldehydes, ketones, esters, carbonates, amines, nitriles, imides, oximes, ureas, or amide functional groups, or from compounds comprising furan rings or sugars.

[0111] The oxygen-containing organic compound may be a compound comprising one or more chemical functional groups selected from carboxylic acids, alcohols, ethers, aldehydes, ketones, esters, or carbonate functional groups, or one or more compounds selected from compounds comprising furan rings or sugars. For example, oxygen-containing organic compounds include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol (molecular weight 200 to 1500 g / mol), propylene glycol, 2-butoxyethanol, 2-(2-butoxyethoxy)ethanol, 2-(2-methoxyethoxy)ethanol, triethylene glycol dimethyl ether, glycerol, acetophenone, 2,4-pentanedione, pentanone, acetic acid, maleic acid, malic acid, malonic acid, oxalic acid, gluconic acid, tartaric acid, citric acid, γ-ketovaleric acid, di(C1-C4 alkyl) succinate, and more specifically dimethyl succinate, methyl acetoacetate, ethyl acetoacetate, 2-methoxyethyl 3-oxobutanoate, and 2-methacryloyloxyethyl 3-Oxobutanoate, Dibenzofuran, Crown Ether, Orthophthalic Acid, Glucose, Fructose, Sucrose, Sorbitol, Xylitol, γ-Valerolactone, 2-Acetylbutyrolactone, Propylene Carbonate, 2-Furaldehyde (also known as Furfural), 5-Hydroxymethylfurfural (also known as 5-(hydroxymethyl)-2-Furaldehyde or 5-HMF), 2-Acetylfuran, 5-Methyl-2-Furaldehyde, Methyl 2-Furoate, Furfuryl Alcohol (also known as Furfuranol), Furfuryl Acetate, Ascorbic Acid, Butyl Lactate, Butyl Butyryl Lactate, Ethyl 3-Hydroxybutanoate, Ethyl It may be one or more compounds selected from the group consisting of 3-ethoxypropanoate, methyl 3-methoxypropanoate, 2-ethoxyethyl acetate, 2-butoxyethyl acetate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and 5-methyl-2(3H)-furanone.

[0112] The nitrogen-containing organic compound may be one or more compounds selected from compounds comprising one or more chemical functional groups selected from amine or nitrile functional groups. For example, the nitrogen-containing organic compound may be one or more compounds selected from the group consisting of ethylenediamine, diethylenetriamine, hexamethylenediamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, acetonitrile, octylamine, guanidine, and carbazole.

[0113] Organic compounds containing oxygen and nitrogen may be one or more compounds selected from compounds comprising one or more chemical functional groups selected from carboxylic acids, alcohols, ethers, aldehydes, ketones, esters, carbonates, amines, nitriles, imides, amides, ureas, or oximes. Examples of organic compounds containing oxygen and nitrogen include 1,2-cyclohexanediaminetetraacetic acid, monoethanolamine (MEA), 1-methyl-2-pyrrolidinone, dimethylformamide, ethylenediaminetetraacetic acid (EDTA), alanine, glycine, nitrilotriacetic acid (NTA), N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid (HEDTA), diethylenetriaminepentaacetic acid (DTPA),

[0114] It may be one or more compounds selected from the group consisting of tetramethylurea, glutamic acid, dimethylglyoxime, bicine, tricin, 2-methoxyethyl cyanoacetate, 1-ethyl-2-pyrrolidinone, 1-vinyl-2-pyrrolidinone, 1,3-dimethyl-2-imidazolidinone, 1-(2-hydroxyethyl)-2-pyrrolidinone, 1-(2-hydroxyethyl)-2,5-pyrrolidinone, 1-methyl-2-piperidinone, 1-acetyl-2-azephanone, 1-vinyl-2-azephanone, and 4-aminobutanoic acid.

[0115] The sulfur-containing organic compound may be one or more compounds selected from compounds comprising one or more chemical functional groups selected from thiols, thioethers, sulfones, or sulfoxide functional groups. For example, the sulfur-containing organic compound may be one or more compounds selected from the group consisting of thioglycolic acid, 2,2'-thiodiethanol, 2-hydroxy-4-methylthiobutanoic acid, sulfone derivatives of benzothiophen or sulfoxide derivatives of benzothiophen, methyl 3-(methylthio)propanoate, and ethyl 3-(methylthio)propanoate.

[0116] Preferably, the organic compound contains oxygen; Preferably, it is γ-valerolactone, 2-acetylbutyrolactone, triethylene glycol, diethylene glycol, ethylene glycol, ethylenediaminetetraacetic acid (EDTA), maleic acid, malonic acid, citric acid, gluconic acid, dimethyl succinate, glucose, fructose, sucrose, sorbitol, xylitol, γ-ketovaleric acid, dimethylformamide, 1-methyl-2-pyrrolidinone, propylene carbonate, 2-methoxyethyl 3-oxobutanoate, bicine, trisine, 2-furaldehyde (also known as furfural), 5-hydroxymethylfurfural (also known as 5-(hydroxymethyl)-2-furaldehyde or 5-HMF), 2-acetylfuran, 5-methyl-2-furaldehyde, ascorbic acid, It is selected from butyl lactate, ethyl 3-hydroxybutanoate, ethyl 3-ethoxypropanoate, 2-ethoxyethyl acetate, 2-butoxyethyl acetate, 2-hydroxyethyl acrylate, 1-vinyl-2-pyrrolidinone, 1,3-dimethyl-2-imidazolidinone, 1-(2-hydroxyethyl)-2-pyrrolidinone, 1-(2-hydroxyethyl)-2,5-pyrrolidinone, 5-methyl-2(3H)-furanone, 1-methyl-2-piperidinone and 4-aminobutanoic acid.

[0117] The contact step b) includes several embodiments. These can be performed simultaneously with (after impregnation) or (before impregnation) the impregnation (co-impregnation) of a compound containing a metal from group VIb, in particular, and are distinguished by the moment of introduction of the organic compound where present. Additionally, it is possible to combine the embodiments.

[0118] Advantageously, after each impregnation step, whether it is a metal and optionally an impregnation step of phosphorus or an organic compound, the impregnated support is left to be aged.

[0119] Any curing step is advantageously performed at atmospheric pressure, a water-saturated atmosphere, and a temperature of 17°C to 50°C, and preferably at ambient temperature. Generally, a curing time of 10 minutes to 48 hours, preferably 30 minutes to 6 hours, is sufficient.

[0120] Any impregnation solution described in the present invention may comprise any polar solvent known to those skilled in the art. The polar solvent used is advantageously selected from the group formed by methanol, ethanol, water, phenol, and cyclohexanol, taken alone or as a mixture. The polar solvent may also advantageously be selected from the group formed by propylene carbonate, DMSO (dimethyl sulfoxide), N-methylpyrrolidone (NMP), and sulfolane, taken alone or as a mixture. Preferably, a polar aprotic solvent is used. A list of conventional polar solvents and their dielectric constants is available in the literature [Solvents and Solvent Effects in Organic Chemistry, C. Reichardt, Wiley-VCH, 3 It can be found in [3rd Edition, 2003, pages 472-474]. Most preferably, the solvent used is water or ethanol, and particularly preferably, the solvent is water. In one possible embodiment, the solvent may not be present in the impregnation solution.

[0121] Drying (step c)

[0122] According to drying step c) of the recovery method according to the present invention, the recovered catalyst obtained in step b) undergoes a drying step at a temperature of less than 200°C, advantageously 50°C to 180°C, preferably 70°C to 150°C, and very preferably 75°C to 130°C.

[0123] The drying step is primarily performed under an inert atmosphere or an oxygen-containing atmosphere. The drying step may be performed by any technique known to those skilled in the art. It is advantageous to perform this at atmospheric pressure or reduced pressure. Preferably, this step is performed at atmospheric pressure. It is advantageously performed on a transverse bed using hot air or any other hot gas. Preferably, when drying is performed on a stationary bed, the gas used is air or an inert gas such as argon or nitrogen. Most preferably, drying is performed on a transverse bed in the presence of nitrogen and / or air. Preferably, the drying step has a duration of 5 minutes to 15 hours, preferably 30 minutes to 12 hours.

[0124] According to the first alternative form, advantageously where an organic compound is present, drying is preferably performed to retain at least 30 weight percent of the organic compound introduced during the impregnation step; preferably, this amount is greater than 50 weight percent, more preferably greater than 70 weight percent, calculated based on the carbon remaining on the recovered catalyst.

[0125] At the end of the drying step c), the recovered catalyst is obtained, and this catalyst will undergo a selective activation (sulfurization) step for its subsequent use in the hydrodesulfurization method of gasoline.

[0126] Hasso (optional step d)

[0127] According to another alternative form, at the end of the drying step c), the calcination step d) is performed at a temperature of 200°C to 600°C, preferably 250°C to 550°C, under an inert atmosphere (e.g., nitrogen) or an oxygen-containing atmosphere (e.g., air). The duration of this heat treatment is generally 0.5 to 16 hours, preferably 1 to 5 hours. After this treatment, the active phase is thus found in the form of an oxide, and the catalyst no longer contains organic compounds or contains very few organic compounds when it was introduced. However, the dispersibility of the active phase can be improved by introducing organic compounds during the preparation, and thus may result in a more active and / or more selective catalyst.

[0128] Sulfation (selective stage)

[0129] Before contacting the feedstock to be treated in the hydrodesulfurization method of gasoline, the recovered catalyst of the method according to the present invention generally undergoes a sulfidation step. Sulfation is preferably performed to convert metal oxides into sulfides, e.g., MoS2 and Co9S8. , In a sulfur-reducing medium , in other words H2S and is carried out in the presence of hydrogen. Sulfation is decomposed in the presence of a catalyst, H2S and hydrogen, or otherwise in the presence of a catalyst and hydrogen, resulting in H 2SThis is carried out by injecting a stream containing a sulfur compound capable of providing. Polysulfides such as dimethyl disulfide (DMDS) are H2S precursors commonly used in sulfide catalysts. Sulfur can also originate from the feedstock. The temperature is adjusted so that H2S reacts with the metal oxide to form a metal sulfide. This sulfidation can be carried out at a temperature of 200°C to 600°C, more preferentially at 300°C to 500°C, at a specific location or another location (inside or outside the reactor) of the reactor of the method according to the present invention.

[0130] Hydrodesulfurization method

[0131] The present invention also relates to a hydrodesulfurization method for a sulfur-containing olefinic gasoline cut, wherein the gasoline cut, hydrogen, and a catalyst recovered according to the method of the present invention are in contact, and the method is defined as a temperature of 200°C to 400°C, preferably 230°C to 330°C, a total pressure of 1 to 3 MPa, preferably 1.5 to 2.5 MPa, and a flow rate per volume of feedstock relative to the volume of catalyst, wherein the method is defined as 1 to 10 h -1 , preferably 2 to 6 h -1 It is carried out at an hourly space velocity (HSV) of 100 to 1200 Sl / l, preferably 150 to 400 Sl / l, and a hydrogen / gasoline feedstock ratio per volume of 100 to 1200 Sl / l.

[0132] The hydrodesulfurization method according to the present invention enables the conversion of organic sulfur compounds in a gasoline cut into hydrogen sulfide (H2S), while limiting the hydrogenation of olefins present in the cut as much as possible.

[0133] feedstock to be processed

[0134] The method according to the present invention enables the processing of any type of sulfur-containing olefinic gasoline cut, such as a cut originating from a coking, bisbraking, steam cracking, or catalytic cracking (FCC, fluid catalytic cracking) unit. This gasoline may optionally consist of a significant fraction of gasoline originating from other production methods, such as atmospheric distillation (gasoline originating from direct distillation (or straight-line gasoline)), or from a conversion method (coking or steam cracking gasoline). The feedstock preferably consists of a gasoline cut originating from a catalytic cracking unit.

[0135] The feedstock is a sulfur-containing olefinic gasoline cut, and its boiling point range typically extends from the boiling points of hydrocarbons having 2 or 3 carbon atoms (C2 or C3) to 260°C, preferably from the boiling points of hydrocarbons having 2 or 3 carbon atoms (C2 or C3) to 220°C, and more preferably from the boiling points of hydrocarbons having 5 carbon atoms to 220°C. The method according to the present invention can also process feedstocks having a lower endpoint than those mentioned above, such as, for example, a C5-180°C cut.

[0136] The sulfur content of gasoline cuts produced by catalytic cracking (FCC) depends not only on the endpoint of the cut but also on the sulfur content of the feedstock processed by the FCC and whether or not the feedstock for the FCC is pretreated. Generally, the sulfur content of the entire gasoline cut, especially those originating from the FCC, is greater than 100 ppm by weight, and mostly greater than 500 ppm by weight. For gasoline with an endpoint greater than 200°C, the sulfur content is often greater than 1000 ppm by weight; these can even, in certain cases, reach values ​​of approximately 4000 to 5000 ppm by weight.

[0137] In addition, gasolines produced from a catalytic cracking (FCC) unit contain, on average, 0.5% to 5% by weight of diolefins, 20% to 50% by weight of olefins, and 10% to 0.5% by weight of sulfur, and generally contain less than 300% by weight of mercaptans. The mercaptans are generally concentrated into the light fractions of the gasoline, more specifically into fractions with a boiling point of less than 120°C.

[0138] It should be noted that sulfur compounds present in gasoline may also include heterocyclic sulfur compounds, e.g., thiophene, alkylthiophene, or benzothiophene. Unlike mercaptans, these heterocyclic compounds cannot be removed by extraction methods. Consequently, these sulfur compounds are removed by hydrogenation, which results in their conversion into hydrocarbons and H2S.

[0139] Preferably, the gasoline processed by the method according to the present invention is heavy gasoline (or HCN for Heavy Cracked Naphtha) resulting from a distillation step for the purpose of separating the broad cut of gasoline resulting from a cracking method (or FRCN for Full Range Cracked Naphtha) into light gasoline (LCN for Light Cracked Naphtha) and heavy gasoline HCN. The cut points of the light gasoline and heavy gasoline are determined to limit the sulfur content of the light gasoline and, preferably, to enable its use in the gasoline pool without further post-treatment. Advantageously, the broad cut FRCN is applied to the optional hydrogenation step described below prior to the distillation step.

[0140] The hydrodesulfurization method may be carried out in a series of one or more reactors of a fixed bed type or an evulate bed type. When the method is carried out in series by at least two reactors, it is possible to provide a device for removing H2S from the effluent originating from the first hydrodesulfurization reactor before treating the effluent in the second hydrodesulfurization reactor.

[0141] The hydrodesulfurization method according to the present invention is carried out in the presence of a recovered catalyst. It may also be carried out in the presence of a mixture of the recovered catalyst and a new or regenerated catalyst.

[0142] Where a new or regenerated catalyst is present, it comprises at least one metal from Group VII, at least one metal and oxide support from Group VIb, and optionally phosphorus and / or an organic compound as described above.

[0143] The active phase and support of the new or regenerated catalyst may or may not be the same as the support and active phase of the recovered catalyst.

[0144] The active phase and support of the new catalyst may or may not be the same as the active phase and support of the regenerated catalyst.

[0145] The above hydrodesulfurization method can be carried out in a fixed-bed type reactor comprising several catalyst beds when carried out in the presence of a recovered catalyst and a new or regenerated catalyst.

[0146] In this case, and according to the first alternative form, a catalyst bed containing a new or regenerated catalyst may precede a catalyst bed containing a recovered catalyst in the direction of feedstock circulation.

[0147] In this case, and according to a second alternative form, a catalyst bed containing the recovered catalyst may precede a catalyst bed containing a new or regenerated catalyst in the direction of feedstock circulation.

[0148] In this case, and according to a third alternative form, the catalyst bed may include a mixture of the recovered catalyst and a new catalyst and / or a regenerated catalyst.

[0149] In this case, the operating conditions are as described above. They are generally the same in different catalyst beds, except for the temperature increase in the catalyst bed after the exothermic reaction of the hydrodesulfurization reaction.

[0150] When a hydrodesulfurization method is carried out in a series of fixed-bed or ebulate-bed type reactors in the presence of a recovered catalyst and a new or regenerated catalyst, one reactor may contain a regenerated catalyst, while another reactor may contain a new or regenerated catalyst, or a mixture of a recovered catalyst and a new and / or regenerated catalyst, and these in any order. H from the effluent originating from the first hydrodesulfurization reactor before treating the effluent in the second hydrodesulfurization reactor 2S It is possible to provide a device for removing [something]. In this case, the operating conditions are as described above and may be the same or different in different reactors.

[0151] Selective hydrogenation (selective step)

[0152] According to one alternative form, the gasoline cut undergoes an optional hydrogenation step prior to the hydrodesulfurization method according to the present invention.

[0153] Preferably, the gasoline treated by the hydrodesulfurization method according to the present invention is heavy gasoline resulting from a distillation step for the purpose of separating the broad cut of gasoline resulting from a cracking method (or FRCN for full range cracking naphtha) into light gasoline and heavy gasoline.

[0154] Advantageously, broad-cut FRCN is applied to the selective hydrogenation step described below before the distillation step.

[0155] The above FRCN cut is pre-treated in the presence of hydrogen and a selective hydrogenation catalyst to at least partially hydrogenate the diolefin and perform a reaction to increase the molecular weight of some of the mercaptan (RSH) compounds present in the feedstock, thereby providing a thioether by reaction with the olefin.

[0156] To this end, the broad FRCN cut is sent to a selective hydrogenation catalytic reactor comprising at least one fixed or moving bed of catalyst for the selective hydrogenation of the diolefin and for increasing the molecular weight of the mercaptan. The reaction for the selective hydrogenation of the diolefin and for increasing the molecular weight of the mercaptan is preferentially carried out on a sulfide catalyst comprising at least one element from Group VIII and optionally at least one element from Group VIb and an oxide support. The element from Group VIII is preferably selected from nickel and cobalt, particularly nickel. The element from Group VIb, if present, is preferably selected from molybdenum and tungsten, very preferably molybdenum.

[0157] The oxide support of the catalyst is preferably selected from alumina, nickel aluminate, silica, silicon carbide, or a mixture of these oxides. Preferably, it is alumina, and more preferably, high-purity alumina is used. According to a preferred embodiment, the selective hydrogenation catalyst contains nickel in a content of 1% to 12% by weight of nickel oxide (in the form of NiO) and molybdenum in a content of 6% to 18% by weight of molybdenum oxide (in the form of MoO3), the nickel / molybdenum molar ratio is 0.3 to 2.5, the metal is deposited on a support made of alumina, and the degree of sulfidation of the metal constituting the catalyst is greater than 50%.

[0158] During an optional optional hydrogenation step, the gasoline is at a temperature of 50°C to 250°C, preferably 80°C to 220°C, more preferably 90°C to 200°C, for 0.5 h -1 to 20 h -1 The catalyst comes into contact with the catalyst at a liquid space velocity (LHSV), and the unit of liquid space velocity is liters of feedstock per liter of catalyst and per hour (l / lh). The pressure is 0.4 MPa to 5 MPa, preferably 0.6 to 4 MPa, and more preferably 1 to 2 MPa. An optional hydrogenation step typically involves an H2 / gasoline feedstock ratio of 2 to 100 Sm³ of hydrogen per cubic meter of feedstock, preferably 3 to 30 Sm³ of hydrogen per cubic meter of feedstock. 2 It is performed based on the gasoline feedstock ratio.

[0159] Examples

[0160] Example 1 - Preparation of a new calcined catalyst A (comparison)

[0161] The support for catalyst A is transition alumina having a specific surface area of ​​140 m² / g and a pore volume of 1.0 cm³ / g. Catalyst A is prepared by dry impregnating the support with an aqueous solution of ammonium heptamolybdate and cobalt nitrate, wherein the volume of the solution containing the metal precursors is strictly equal to the pore volume of the mass of the support. The concentration of the metal precursors in the aqueous solution is adjusted to obtain the desired weight percent of molybdenum and cobalt in the final catalyst. After dry impregnation in the support, the catalyst is heated in a water-saturation chamber for 1 hour and 30 minutes, dried in air in an oven at 90°C for 12 hours, and then calcined in air at 450°C for 2 hours.

[0162] The new catalyst A obtained after calcination has a content of 9.6 wt% molybdenum (MoO3 equivalent) and 2.2 wt% cobalt (CoO equivalent). This catalyst exhibits a Co / Mo atomic ratio of 0.44 and a specific surface area of ​​123 m² / g.

[0163] Example 2 - Preparation of Regenerated Calcined Catalyst A (Comparison)

[0164] The above-described new catalyst is used for the desulfurization of catalytic cracking (FCC) gasoline, and its characteristics are verified in Table 1. The reaction is carried out in a cross-bed type reactor at 270°C for 900 hours under the following conditions: P = 2 MPa, HSV = 4 h -1 , hydrocarbon feedstock with H2 / HC = 300 liters / liter. To provide sulfation on oxides, the catalyst is pretreated at 350°C with a feedstock containing 4 wt% sulfur in the form of DMDS (dimethyl disulfide). The reaction is carried out in an upstream direction in an isothermal pilot reactor.

[0165] Table 1

[0166]

[0167] The consumed catalyst is recovered from the reactor after the completion of the hydrodesulfurization of the catalytic cracking (FCC) gasoline described above. Subsequently, the consumed catalyst is washed (de-oiled) with toluene in a Soxhlet at 250°C for 7 hours. Subsequently, the regeneration of the consumed / washed catalyst A is performed in a tubular oven under dry air at 450°C for 2 hours, and the regenerated catalyst A is obtained. The residual carbon content of the regenerated catalyst A is 0. Example 3 - Preparation of calcined recovered catalyst B1 by addition of Co and Mo (not according to the present invention)

[0168] Catalyst B1 is prepared by dry impregnating regenerated catalyst A with an aqueous solution of ammonium heptamolybdate and cobalt nitrate, wherein the volume of the solution containing the metal precursor is strictly equal to the pore volume of the mass of regenerated catalyst A. The concentration of the metal precursor in the aqueous solution is adjusted to obtain the desired weight percent of molybdenum and cobalt in the final catalyst. After dry impregnation of the regenerated catalyst A, the catalyst is heated in a water saturation chamber for 1 hour and 30 minutes, dried in an oven at 90°C for 12 hours, and then calcined in air at 450°C for 2 hours.

[0169] Catalyst B1 obtained after calcination has a content of 10.8 wt% molybdenum (MoO3 equivalent) and 2.4 wt% cobalt (CoO equivalent), a Co / Mo atomic ratio of 0.43, and a specific surface area of ​​122 m 2 / g. The molar ratio of the added metal from group VIb to the metal from group VIb already present in the regenerated catalyst A is 0.125 mol / mol.

[0170] Example 4 - Preparation of dried recovered catalyst B2 by addition of Co and Mo (present invention number of people (According to)

[0171] Catalyst B2 is prepared by dry impregnating regenerated catalyst A with an aqueous solution of ammonium heptamolybdate and cobalt nitrate, wherein the volume of the solution containing the metal precursor is strictly equal to the pore volume of the mass of regenerated catalyst A. The concentration of the metal precursor in the aqueous solution is adjusted to obtain the desired weight percent of molybdenum and cobalt in the final catalyst. After dry impregnation of the regenerated catalyst A, catalyst B2 is heated in a water-saturated chamber for 1 hour and 30 minutes and dried under air in an oven at 90°C for 12 hours.

[0172] The catalyst B2 obtained after drying has a content of 13.8 wt% molybdenum (MoO3 equivalent) and 3.6 wt% cobalt (CoO equivalent), a Co / Mo atomic ratio of 0.50, and a specific surface area of ​​116 m² / g. The molar ratio of the added metal from group VIb to the metal from group VIb already present in the regenerated catalyst A is 0.44 mol / mol.

[0173] Example 5 - Preparation of calcined recovered catalyst B3 by addition of Co and Mo (according to the present invention)

[0174] Catalyst B3 is obtained by calcining catalyst B2 at 450°C for 2 hours under air.

[0175] Example 6 - Preparation of recovered catalyst B4 by addition of Co, Mo and P (according to the present invention)

[0176] Catalyst B4 is prepared by dry impregnating regenerated catalyst A with an aqueous solution of molybdenum oxide, cobalt hydroxide, and orthophosphoric acid, wherein the volume of the solution containing the metal precursors is strictly equal to the pore volume of the mass of regenerated catalyst A. The concentration of the metal precursors in the aqueous solution is adjusted to obtain the desired weight percent of molybdenum, cobalt, and phosphorus in the final catalyst. After dry impregnation of the regenerated catalyst A, catalyst B4 is heated in a water-saturated chamber for 1 hour and 30 minutes and dried under air in an oven at 120°C for 12 hours.

[0177] Catalyst B4 obtained after drying has a content of 12.4 wt% molybdenum (MoO3 equivalent), 2.6 wt% cobalt (CoO equivalent), and 1.2 wt% phosphorus (P2O5 equivalent), a Co / Mo atomic ratio of 0.40, a P / Mo atomic ratio of 0.20, and a specific surface area of ​​117 m² / g. The molar ratio of the added metal from group VIb to the metal from group VIb already present in the regenerated catalyst A is 0.3 mol / mol.

[0178] Example 7 - Preparation of recovered catalyst B5 by addition of Co, Mo, P citric acid (according to the present invention)

[0179] Catalyst B5 is prepared by dry impregnating regenerated catalyst A with an aqueous solution of molybdenum oxide, cobalt hydroxide, orthophosphoric acid, and citric acid, wherein the volume of the solution containing the metal precursors is strictly equal to the pore volume of the mass of regenerated catalyst A. The concentration of the metal precursors in the aqueous solution is adjusted to obtain the desired weight percent of molybdenum, cobalt, and phosphorus in the final catalyst. The molar ratio of citric acid to molybdenum in the final catalyst is 0.4. After dry impregnation of the regenerated catalyst A, catalyst B5 is heated in a water-saturated chamber for 1 hour and 30 minutes and dried under air in an oven at 120°C for 12 hours.

[0180] Catalyst B5 obtained after drying has a content of 15.5 wt% molybdenum (MoO3 equivalent), 3.4 wt% cobalt (CoO equivalent), and 2.4 wt% phosphorus (P2O5 equivalent), with a Co / Mo atomic ratio of 0.42, a P / Mo atomic ratio of 0.31, and a specific surface area of ​​110 m² / g. The molar ratio of the added metal from Group VIb to the metal from Group VIb already present in the regenerated catalyst A is 0.61 mol / mol.

[0181] Example 8 - Evaluation of catalyst performance quality of catalyst A (regenerated), B1, B2, B3, B4, and B5

[0182] A model feedstock representing catalytic cracking (FCC) gasoline containing 10 wt% 2,3-dimethylbut-2-ene and 0.33 wt% 3-methylthiophene (i.e., 1000 wt ppm sulfur in the feedstock) is used to evaluate the catalytic performance quality of various catalysts. The solvent used is heptane.

[0183] Hydrodesulfurization (HDS) reaction was carried out in the presence of 4 ml of catalyst, at a total pressure of 1.5 MPa, 210°C, and HSV = 6 h -1 It is carried out in a fixed cross-bed reactor under (HSV = feedstock volume / flow rate per volume of catalyst) and a volumetric H2 / feedstock ratio of 300 Sl / l. Prior to the HDS reaction, the catalyst is 15 mol% H2S at atmospheric pressure. It is sulfidated in place at 350°C for 2 hours under a flow of hydrogen containing it.

[0184] Each catalyst is sequentially placed in the reactor. Samples are taken at different time intervals and analyzed by gas chromatography to observe the loss of reactants and the formation of products.

[0185] The catalytic performance quality of a catalyst is evaluated in terms of catalytic activity and selectivity. Hydrodesulfurization (HDS) activity is expressed from the rate constant (kHDS) for the HDS reaction of 3-methylthiophene, standardized by the volume of the introduced catalyst, assuming first-order kinetics for sulfur compounds. Hydrogenation activity of olefins (HydO) is expressed from the rate constant for the hydrogenation reaction of 2,3-dimethylbut-2-ene, standardized per volume of the introduced catalyst, assuming first-order kinetics for olefins.

[0186] The selectivity of the catalyst is expressed as the standardized ratio of the rate constant kHDS / kHydO. The kHDS / kHydO ratio will be higher when the catalyst is more selective. The obtained value was standardized against catalyst A (relative HDS activity and relative selectivity are equivalent to 100). Therefore, the performance quality is relative HDS activity and relative selectivity.

[0187] Table 2

[0188]

[0189] The recovered catalysts B2, B3, B4, and B5 exhibit greater activity for the hydrogenation of olefins and improved selectivity in hydrodesulfurization compared to comparative catalysts A (regenerated) and B1.

[0190] This improvement in catalyst selectivity is particularly advantageous when used in hydrodesulfurization methods for olefin-containing gasoline, which seek to limit the loss of octane due to the hydrogenation of olefins as much as possible.

Claims

Claim 1 A method for the rejuvenation of at least partially consumed catalyst resulting from a hydrodesulfurization method of a sulfur-containing olefinic gasoline cut, wherein the at least partially consumed catalyst is derived from a new catalyst comprising cobalt, molybdenum, an oxide support, and optionally phosphorus, and the method comprises: a) a step of regenerating the at least partially consumed catalyst in an oxygen-containing gas stream at a temperature of 350°C to 550°C to obtain a regenerated catalyst; b) a step of contacting the regenerated catalyst with at least one impregnation solution comprising water, at least one compound comprising molybdenum, and at least one compound comprising cobalt, wherein the impregnation solution does not contain phosphorus and organic compound additives, and the molar ratio of added molybdenum per molybdenum already present in the regenerated catalyst is 0.3 to 1.0 mol / mol, and the molar ratio of added cobalt per cobalt already present in the regenerated catalyst is 0.1 to 2.5 mol / mol. A method for recovering at least partially consumed catalyst resulting from a hydrodesulfurization method of a sulfur-containing olefinic gasoline cut, comprising: step c) a drying step performed at a temperature of less than 200°C to obtain a recovered catalyst. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 delete Claim 6 delete Claim 7 A method for recovering at least partially consumed catalyst resulting from a hydrodesulfurization method of a sulfur-containing olefinic gasoline cut, wherein, in claim 1, a de-oiling step comprising contacting at least partially consumed catalyst with a stream of inert gas at a temperature of 300°C to 400°C is preceded before a regeneration step a). Claim 8 A method for recovering at least partially consumed catalyst resulting from a hydrodesulfurization method of a sulfur-containing olefin-based gasoline cut, wherein, at the end of the drying step c), the calcination step d) is performed at a temperature of 200°C to 600°C. Claim 9 A method for recovering at least partially consumed catalyst resulting from a hydrodesulfurization method of a sulfur-containing olefinic gasoline cut, wherein the new catalyst has a molybdenum content of 1% to 20% by weight of molybdenum oxide relative to the total weight of the catalyst, and a cobalt content of 0.1% to 10% by weight of cobalt oxide relative to the total weight of the catalyst. Claim 10 A method for recovering at least partially consumed catalyst resulting from a hydrodesulfurization method of a sulfur-containing olefinic gasoline cut, wherein the new catalyst has a content of 0.3% to 10% by weight of P2O5 relative to the total weight of the catalyst, and the phosphorus / (molybdenum) molar ratio in the catalyst is 0.1 to 0.

7. Claim 11 A method for recovering at least partially consumed catalyst resulting from a hydrodesulfurization method of a sulfur-containing olefinic gasoline cut, wherein the oxide support of the new catalyst is selected from alumina, silica, silica-alumina, titanium oxide, magnesium oxide, titanium or magnesium oxide used as a mixture with alumina, or titanium or magnesium oxide used as a mixture with silica-alumina. Claim 12 A method for recovering at least partially consumed catalyst resulting from a hydrodesulfurization method of a sulfur-containing olefin-based gasoline cut, wherein the new catalyst is characterized by a specific surface area of ​​20 to 200 m² / g or 30 to 180 m² / g. Claim 13 A hydrodesulfurization method for a sulfur-containing olefinic gasoline cut in which a gasoline cut, hydrogen, and a catalyst recovered according to any one of claims 1 and 7 to 12 are brought into contact, wherein the hydrodesulfurization method comprises a temperature of 200°C to 400°C, a total pressure of 1 to 3 MPa, and 1 to 10 h -1 A hydrodesulfurization method for a sulfur-containing olefinic gasoline cut, performed at an hourly space velocity defined as the flow rate per volume of feedstock relative to the volume of catalyst, and a hydrogen / gasoline feedstock ratio per volume of 100 to 1200 Sl / l. Claim 14 In claim 13, the hydrodesulfurization method of a sulfur-containing olefinic gasoline cut, wherein the recovered catalyst undergoes a sulfidation step before or during the hydrodesulfurization method. Claim 15 A method for hydrodesulfurizing a sulfur-containing olefinic gasoline cut, wherein the method is performed in a catalyst bed of a fixed-bed type reactor comprising several catalyst beds; and at least one other catalyst bed upstream or downstream of the catalyst bed containing the recovered catalyst in the direction of circulation of the feedstock comprises at least partially a new catalyst and / or a regenerated catalyst. Claim 16 A hydrodesulfurization method for a sulfur-containing olefinic gasoline cut, wherein the method is carried out in a series of at least two fixed-bed or ebulate-bed type reactors, wherein at least one of the at least two reactors contains a recovered catalyst, while another reactor contains a new catalyst or a regenerated catalyst, or a mixture of a new and / or regenerated catalyst and a recovered catalyst, wherein the reactor containing the recovered catalyst and the reactor containing the new catalyst or a regenerated catalyst, or a mixture of a new and / or regenerated catalyst and a recovered catalyst, are arranged in any order, and the method is carried out with or without removing at least a portion of H2S from the effluent originating from the first of the series of at least two reactors before treating the effluent from the second of the series of at least two reactors.

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