Process for hydrodesulfurization of sulfur-containing olefinic gasoline using a catalyst with rejuvenating activity of organic compounds

Abstract

The present invention relates to a process for hydrodesulfurization of a sulfur containing olefinic gasoline fraction, wherein the gasoline fraction, hydrogen and a rejuvenated catalyst are contacted, the hydrodesulfurization process being carried out at a temperature of 200-400 °C, at a total pressure of 1-3 MPa, at a space time velocity of 1-10 h ‑1 The space time velocity is defined as the feed volume flow rate relative to the catalyst volume, the rejuvenated catalyst is produced by a hydrotreatment process and comprises at least one Group VIII metal, at least one Group VIB metal, an oxidic support and at least one organic compound containing oxygen and / or nitrogen and / or sulfur.

Description

[0001] This application is a divisional application of the following application: filed on December 10, 2019, application number 201980084690.4, invention title "Method for hydrodesulfurization of sulfur-containing olefin gasoline using a catalyst with restoring activity of organic compounds". Invention Field

[0002] This invention relates to a method for hydrodesulfurizing gasoline fractions using a catalyst with restored activity. Background Technology

[0003] Sulfur is a naturally occurring element in crude oil, and therefore, if not removed during refining, it remains in gasoline and petroleum gas. However, sulfur in gasoline interferes with the efficiency of emission reduction systems (catalytic converters) and contributes to air pollution. To combat environmental pollution, all countries have gradually adopted strict sulfur regulations, such as 10 ppm (by weight) for sulfur content in gasoline sold in Europe, China, the United States, and Japan. The focus of reducing sulfur content is primarily on gasoline obtained through cracking, whether catalytic (FCC, fluid catalytic cracking) or non-catalytic (coking, viscous cracking, steam cracking), as these are major precursors to sulfur in the gasoline pool.

[0004] A solution well known to those skilled in the art for reducing sulfur content involves hydrotreating (or hydrodesulfurizing) hydrocarbon fractions (especially catalytic cracking gasoline) in the presence of hydrogen and a heterogeneous catalyst. However, this approach exhibits a major drawback of causing a very significant reduction in octane number if the catalyst used is not sufficiently selective. This reduction in octane number is particularly related to the hydrogenation of olefins present in this type of gasoline (which is accompanied by hydrodesulfurization).

[0005] Unlike other hydrotreating methods, especially those used for gas oil-type materials, gasoline hydrodesulfurization must therefore allow for a dual conflicting constraint: ensuring deep hydrodesulfurization of gasoline and limiting the hydrogenation of unsaturated compounds present.

[0006] The most widely used approach to address the aforementioned dual problem lies in employing a method in which the sequence of unit steps allows for maximizing hydrodesulfurization while limiting olefin hydrogenation. Thus, more recent methods, such as the Prime G+ (trademarked) method, allow for the desulfurization of olefin-rich cracked gasoline while limiting the hydrogenation of mono-olefins, and therefore limiting octane loss and the resulting high hydrogen consumption. This approach is described, for example, in patent applications EP1077247 and EP1174485.

[0007] Therefore, achieving the desired reaction selectivity (the ratio of hydrodesulfurization to olefin hydrogenation) can be partly due to the choice of method, but in all cases, the use of an inherently selective catalytic system is often the key factor. Typically, catalysts used for such applications are sulfide-type catalysts containing Group VIb elements (Cr, Mo, W) and Group VIII elements (Fe, Ru, Os, Co, Rh, Ir, Pd, Ni, Pt). Therefore, patent US5985136 claims a surface concentration of 0.5 × 10⁻⁶. -4 -3×10 -4 gMoO3 / m 2 The catalyst allows for high selectivity in hydrodesulfurization (93% hydrodesulfurization (HDS) to 33% olefin hydrogenation (HOO)). Furthermore, according to patents US4140626 and US4774220, it is advantageous to add dopants (alkali metals, alkaline earth metals) to the conventional sulfide phase (CoMoS) to limit the hydrogenation of olefins. Documents US8637423 and EP1892039 are also known in the prior art, describing selective hydrodesulfurization catalysts.

[0008] During hydrotreating of petroleum fractions, the hydrotreating catalyst experiences a decrease in activity due to the deposition of coke and / or sulfur-based or other impurity-containing compounds. Therefore, replacement is necessary after a certain period. In particular, increased sulfur specifications for fuels lead to more frequent catalyst replacements, resulting in increased catalyst-related costs and a greater quantity of degraded catalyst.

[0009] To overcome these drawbacks, the regeneration (mild calcination) of catalysts used for hydrodesulfurization of middle distillates (gas oil) or waste residue is an economically and ecologically advantageous method because it allows these catalysts to be reused in industrial plants instead of landfilling or recycling (recovering metals). However, regenerated catalysts are typically less active than the starting solids. Therefore, patent application US2011 / 0079542 states that, after regeneration, typical commercially available catalysts for the hydrotreatment of distillates can have about 75% to about 90% of the reactivity of the corresponding fresh catalyst.

[0010] To address this issue, in the field of middle distillates, these regenerated catalysts are typically added with various organic reagents ("reactivation" step). Numerous patents, such as US7906447, US8722558, US7956000, US7820579, and CN102463127, thus provide different methods for restoring the activity of catalysts used in the hydrotreating of middle distillates. Catalysts used for hydrodesulfurization of middle distillates, which have higher metal content compared to catalysts used for selective hydrodesulfurization of gasoline, undergo significant sintering during use and regeneration. Therefore, the reactivation treatment focuses on the dissolution and redistribution of the metal phase to recover a dispersion close to that of a fresh catalyst and thus obtain activity close to that of a fresh catalyst.

[0011] Catalysts for selective hydrodesulfurization of gasoline present different regeneration challenges than those for gas oil hydrotreatment, particularly due to the need to maintain selectivity in olefin hydrodesulfurization and hydrogenation reactions. This is because increasing selectivity is generally preferred over increasing or maintaining activity in the gasoline sector. While conventional regeneration is conceivable for selective hydrodesulfurization of gasoline, those skilled in the art will expect catalysts to exhibit significantly lower activity and potentially reduced selectivity than fresh catalysts, as has been demonstrated with catalysts used for the hydrotreatment of middle distillates, due to structural changes in the active phase supported on the catalyst during regeneration.

[0012] This method for restoring activity is described in patent CN105642312 for a degraded catalyst used in the selective hydrodesulfurization of FCC gasoline. In addition to organic reagents, this complex method uses one or more metal additives containing at least one element selected from Na, K, Mg, Ca, Cu, and Zn; and employs heat treatment in an atmosphere with controlled oxygen content.

[0013] Therefore, there remains strong interest in refineries today for methods used in hydrodesulfurization, particularly for gasoline fractions, which exhibit excellent catalytic performance quality, especially in terms of hydrodesulfurization catalytic activity and selectivity, and allow the use of catalysts derived from degraded hydrotreating catalysts.

[0014] Invention Theme Therefore, the present invention relates to a method for hydrodesulfurization of sulfur-containing olefin gasoline fractions, wherein the gasoline fraction, hydrogen, and a reactivated catalyst are contacted, and the hydrodesulfurization method is carried out at a temperature of 200°C to 400°C, a total pressure of 1-3 MPa, for 1-10 h. -1The process is carried out at a space-time velocity (defined as the feed volume flow rate relative to the catalyst volume) and a hydrogen / gasoline feed volume ratio of 100-1200 Sl / l, wherein the catalyst for restoring activity is produced by a hydrotreating method and comprises at least one Group VIII metal, at least one Group VIb metal, an oxide support, and at least one organic compound containing oxygen and / or nitrogen and / or sulfur.

[0015] This is because it has been observed that, compared to using the same fresh catalyst, the use of a catalyst with restored activity of organic compounds in the selective hydrodesulfurization of gasoline results in only a very small loss of activity and surprisingly, an improvement in selectivity. Without relying on any theory, it appears that the change in the active phase caused by the restored catalyst activity, and the resulting better selectivity of the hydrodesulfurization reaction toward the active sites, compensates for the reduction in the number of these sites, thus maintaining the catalyst's activity.

[0016] According to an alternative form, the oxygen- and / or nitrogen- and / or sulfur-containing organic compound is selected from compounds containing one or more chemical functional groups, or compounds containing a furan ring, or sugars, wherein the chemical functional groups are selected from carboxylic acid functional groups, alcohols, thiols, thioethers, sulfones, sulfoxides, ethers, aldehydes, ketones, esters, carbonates, amines, nitriles, imides, oximes, ureas, or amide functional groups.

[0017] According to an alternative form, the organic compound containing oxygen and / or nitrogen and / or sulfur is selected from γ-valerol, 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-ketovalerate, dimethylformamide, 1-methyl-2-pyrrolidone, propylene carbonate, 2-methoxyethyl 3-oxobutyrate, N,N-dihydroxyethylglycine, tris(hydroxymethyl)methylglycine, and 2-furfural. 5-Hydroxymethylfurfural, 2-acetylfuran, 5-methyl-2-furfural, ascorbic acid, butyl lactate, ethyl 3-hydroxybutyrate, ethyl 3-ethoxypropionate, 2-ethoxyethyl acetate, 2-butoxyethyl acetate, 2-hydroxyethyl acrylate, 1-vinyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolinone, 1-(2-hydroxyethyl)-2-pyrrolidone, 1-(2-hydroxyethyl)-2,5-pyrrolidone, 5-methyl-2(3H)-furanone, 1-methyl-2-piperidinone, and 4-aminobutyric acid.

[0018] According to an alternative form, the content of a Group VIb metal in the reactivated catalyst is from 1% to 40% by weight of Group VIb metal oxides relative to the total weight of the reactivated catalyst, and the content of a Group VIII metal is from 0.1% to 10% by weight of said Group VIII metal oxides relative to the total weight of the reactivated catalyst.

[0019] According to one alternative form, the reactivating catalyst further comprises phosphorus, expressed as P2O5, in a phosphorus content of 0.3% to 10% by weight relative to the total weight of the reactivating catalyst, and the phosphorus / (Group VIb metal) molar ratio in the reactivating catalyst is 0.1 to 0.7.

[0020] According to an alternative formulation, the catalyst for restoring activity is characterized by a concentration of 20 to 200 m. 2 / g, preferably 30 to 180m 2 Specific surface area per g.

[0021] According to one alternative form, the oxide support for the revitalized catalyst is selected from alumina, silica, silica-alumina, or titanium or magnesium oxide, used alone or as a mixture with alumina or silica-alumina.

[0022] According to an alternative form, the reactivated catalyst contains less than 2% by weight of residual carbon relative to the total weight of the reactivated catalyst.

[0023] According to an alternative form, the reactivated catalyst contains less than 5% by weight of residual sulfur relative to the total weight of the reactivated catalyst.

[0024] According to one alternative, the reactivated catalyst undergoes a sulfidation step before or during the hydrodesulfurization process.

[0025] According to one alternative, the gasoline fraction is gasoline produced by a catalytic cracking unit.

[0026] According to an alternative form, the method is carried out in a catalytic bed of a fixed-bed type reactor comprising multiple catalytic beds; in the feed circulation direction, at least one other catalytic bed upstream or downstream of the catalytic bed containing the reactivated catalyst at least partially contains fresh catalyst and / or regenerated catalyst.

[0027] According to an alternative form, the method is carried out in at least two fixed-bed or fluidized-bed reactors connected in series; at least one of the reactors contains a reactivated catalyst, while the other reactor contains a fresh or regenerated catalyst, or a mixture of a reactivated catalyst and fresh and / or regenerated catalyst, in any order, to remove or not remove at least a portion of the H2S from the effluent generated from the first reactor before treating the effluent generated from the first reactor in the second reactor.

[0028] Subsequently, the groups of chemical elements are given according to the CAS classification (CRC Handbook of Chemistry and Physics, published by CRC Press, edited by DRLide, 81st edition, 2000-2001). For example, Group VIII according to the CAS classification corresponds to the metals in columns 8, 9, and 10 according to the new IUPAC classification.

[0029] Invention Description Therefore, the present invention relates to a method for hydrodesulfurization of sulfur-containing olefin gasoline fractions, wherein the gasoline fraction, hydrogen, and a reactivated catalyst are contacted, and the hydrodesulfurization method is carried out at a temperature of 200°C-400°C and a total pressure of 1-3 MPa for 1 hour. -1 -10h -1 The space-time velocity (defined as the feed volume flow rate relative to the catalyst volume) and the hydrogen / gasoline feed volume ratio of 100-1200 Sl / l are used to restore the activity of the catalyst, which is produced by a hydrotreating method and contains at least one Group VIII metal, at least one Group VIb metal, an oxide support, and at least one organic compound containing oxygen and / or nitrogen and / or sulfur.

[0030] The hydrodesulfurization method according to the invention enables the conversion of organic sulfur compounds in gasoline fractions into hydrogen sulfide (H2S) while limiting the hydrogenation of olefins present in the fractions as much as possible.

[0031] Feed to be processed The method according to the invention enables the processing of any type of sulfur-containing olefin gasoline fraction, such as fractions produced by coking, viscous cracking, steam cracking, or catalytic cracking (FCC, fluidized bed catalytic cracking) units. This gasoline may optionally consist of a large portion of gasoline from other production or conversion methods (coking or steam cracking gasoline), such as atmospheric distillation (gasoline produced by direct distillation (or straight-run gasoline)). The feedstock preferably consists of gasoline fractions produced by a catalytic cracking unit.

[0032] The feedstock is a sulfur-containing olefin gasoline fraction, whose boiling point range typically extends from the boiling point of hydrocarbons having two or three carbon atoms (C2 or C3) up to 260°C, preferably from the boiling point of hydrocarbons having two or three carbon atoms (C2 or C3) up to a maximum of 220°C, and more preferably from the boiling point of hydrocarbons having five carbon atoms up to a maximum of 220°C. The method according to the invention can also process feedstocks with lower endpoints than those described above, such as C5-180°C fractions.

[0033] The sulfur content of gasoline fractions produced by catalytic cracking (FCC) depends on the sulfur content of the feedstock processed by the FCC, whether the FCC feedstock was pretreated, and the endpoint of the fraction. Typically, the sulfur content in a whole gasoline fraction, especially those derived from FCC, is greater than 100 ppm by weight, and most often greater than 500 ppm by weight. For gasoline with endpoints greater than 200°C, the sulfur content is typically greater than 1000 ppm by weight; in some cases, it can even reach values ​​in the 4000 to 5000 ppm by weight range.

[0034] In addition, gasoline obtained from a catalytic cracking (FCC) unit typically contains 0.5 wt% to 5 wt% dienes, 20 wt% to 50 wt% olefins, and 10 ppm to 0.5 wt% sulfur, usually less than 300 ppm thiols. Thiols are generally concentrated in the lighter fractions of gasoline, more specifically in fractions with boiling points below 120°C.

[0035] It should be noted that sulfur compounds present in gasoline can also include heterocyclic sulfur compounds, such as thiophene, alkylthiophene, or benzothiophene. These heterocyclic compounds, unlike thiols, cannot be removed by extraction. Therefore, these sulfur compounds are removed by hydrogenation, which results in their conversion into hydrocarbons and H₂S.

[0036] Preferably, the gasoline processed by the method according to the invention is heavy gasoline (or HCN, for "heavy cracked naphtha") produced from a distillation step, the purpose of which is to separate the broad fraction (or FRCN, for "full-range cracked naphtha") of gasoline produced by the cracking method into light gasoline (LCN, light cracked naphtha) and heavy gasoline HCN. A cut-off point between light and heavy gasoline is determined to limit the sulfur content of the light gasoline and make it usable in the gasoline pool, preferably without additional post-treatment. Advantageously, the crude fraction FRCN undergoes a selective hydrogenation step as described below prior to the distillation step.

[0037] Catalysts that restore activity The reactivated catalyst is generated from at least partially deactivated catalyst, which itself is generated from fresh catalyst that has been used in the hydrotreating process for a certain period of time and exhibits significantly lower activity than the fresh catalyst, necessitating its replacement. As a first step, the at least partially deactivated catalyst is regenerated, then reactivated by adding at least one organic compound containing oxygen and / or nitrogen and / or sulfur, followed by drying.

[0038] The catalyst for reactivation can be produced by hydrotreating any petroleum fraction (e.g., naphtha, kerosene, gas oil, vacuum distillate, or residue). Hydrotreating should be understood to specifically include reactions such as hydrodesulfurization (HDS), hydronitrogenation (HDN), and aromatics hydrogenation (HOA). It can also be produced by hydrotreating biomass or bio-oils.

[0039] Preferably, the catalyst for restoring activity is produced by a hydrodesulfurization method for sulfur-containing olefin gasoline fractions carried out under the conditions described below.

[0040] The catalyst for restoring activity comprises at least one Group VIII metal, at least one Group VIb metal, an oxide support, and an organic compound comprising oxygen and / or nitrogen and / or sulfur as described below, and optionally phosphorus. According to another alternative form, the catalyst for restoring activity does not contain phosphorus.

[0041] The Group VIb metals present in the active phase of the reactivated catalyst are preferably selected from molybdenum and tungsten. The Group VIII metals present in the active phase of the reactivated catalyst are preferably selected from cobalt, nickel, and mixtures of these two elements. The active phase of the reactivated catalyst is preferably selected from element combinations nickel-molybdenum, cobalt-molybdenum, and nickel-cobalt-molybdenum; very preferably, the active phase consists of cobalt and molybdenum.

[0042] The content of Group VIII metal oxides is 0.1% to 10% by weight relative to the total weight of the catalyst for restoring activity, preferably 0.6% to 8% by weight, more preferably 2% to 7% by weight, very preferably 2% to 6% by weight, and more preferably 2.5% to 6% by weight.

[0043] The content of Group VIb metal oxides is 1% to 40% by weight relative to the total weight of the catalyst for restoring activity, preferably 1% to 25% by weight, and very preferably 2% to 18% by weight.

[0044] The molar ratio of Group VIII metal to Group VIb metal in the catalyst for restoring activity is typically 0.1 to 0.8, preferably 0.2 to 0.6.

[0045] Furthermore, the density of Group VIb metals (expressed as the number of metal atoms per unit area of ​​the catalyst for restoring activity) in the catalyst is 0.5-30, preferably 2-25, and more preferably 3-15 Group VIb metal atoms / nm. 2 Catalyst for reactivation. Density of Group VIb metals, expressed as the number of Group VIb metal atoms per unit area of ​​the catalyst for reactivation (number of Group VIb metal atoms / nm). 2 The catalyst that has been reactivated is represented, for example, by the following relationship: in: • X = weight percentage of Group VIb metals • N A =Avogadro's constant, equal to 6.022 × 10 23 ; • S = Specific surface area of ​​the catalyst (m² / g), measured according to standard ASTM D3663; • M M =Molar mass of Group VIb metals (e.g., molybdenum is 95.94 g / mol).

[0046] 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, then the density d(Mo) is equal to: .

[0047] Optionally, relative to the total weight of the reactivated catalyst, the reactivated catalyst may additionally have a phosphorus content typically from 0.3% to 10% by weight of P2O5, preferably from 0.5% to 5% by weight, and very preferably from 1% to 3% by weight of P2O5. Furthermore, when phosphorus is present, the molar ratio of phosphorus to (Group VIb metals) is typically from 0.1 to 0.7, preferably from 0.2 to 0.6.

[0048] In fresh, at least partially depleted, regenerated, or reactivated catalysts, the contents of Group VIb metals, Group VIII metals, and phosphorus are expressed as oxides after correction for loss on ignition (continuously in a muffle furnace at 550°C for 2 hours). Loss on ignition is due to the loss of moisture, carbon, sulfur, and / or other contaminants. It is determined according to ASTM D7348.

[0049] Preferably, the catalyst for restoring activity is characterized by a specific surface area of ​​5 to 400 m² / g, more preferably 10 to 250 m² / g, more preferably 20 to 200 m² / g, and very preferably 30 to 180 m² / g. In this invention, the specific surface area is determined according to ASTM D3663 standard by the BET method, as described in the book by Rouquerol F., Rouquerol J., and Singh K. Adsorption by Powders&Porous Solids: Principle, Methodology and Applications As described in Academic Press, 1999, for example via Micromeritics TM Autopore III of the brand TM The measurement was performed using a type of equipment.

[0050] The pore volume of the catalyst used for reactivation is typically 0.4 cm³. 3 / g to 1.3cm 3 / g, preferably 0.6cm 3 / g to 1.1cm 3 / g. As described in the same work, the total pore volume was measured by the mercury porosity method according to ASTM D4284, with a wetting angle of 140°.

[0051] The tapped bulk density (TBD) of the reactivated catalyst is typically 0.4–0.7 g / ml, preferably 0.45–0.69 g / ml. TBD measurement involves introducing the catalyst into a pre-determined graduated cylinder and then vibrating it until a constant volume is achieved. The bulk density of the product after tapping is calculated by comparing the introduced mass with the volume occupied after tapping.

[0052] The catalyst can be in the form of a cylindrical or multi-lobed (trilobed, quadrilobed, etc.) extrusion or a sphere with a small diameter.

[0053] The oxide support for the catalyst used to restore activity is typically selected from porous solids including alumina, silica, silica-alumina, titanium dioxide, and magnesium oxide, used alone or as a mixture with alumina or silica-alumina. It is preferably selected from silica, transition alumina, and silica-alumina types; very preferably, the support is substantially composed of at least one transition alumina, that is, it contains at least 51% by weight, preferably at least 60% by weight, very preferably at least 80% by weight, and even at least 90% by weight of transition alumina. It preferably consists only of transition alumina. Preferably, the catalyst support is "high-temperature" transition alumina, that is, it contains, alone or in mixtures, θ-, δ-, κ-, or α-phase alumina, and less than 20% of γ-, χ-, or η-phase alumina.

[0054] The catalyst for restoring activity also contains contaminants generated by the feed, such as carbon, sulfur, and other contaminants such as silicon, arsenic, and chlorine.

[0055] The catalyst for restoring activity contains residual carbon, preferably less than 2% by weight, more preferably from 0.1% to 1.9% by weight, and more preferably from 0.1% to 1.5% by weight, particularly preferably from 0.1% to 1.0% by weight, relative to the total weight of the catalyst for restoring activity. The catalyst for restoring activity may also not contain residual carbon.

[0056] It should be noted that the term "residual carbon" in this patent application refers to the carbon (coke) retained in the reactivated catalyst, which was present after regeneration of the catalyst that was at least partially degraded. The content of residual carbon in the regenerated catalyst is measured by elemental analysis according to ASTM D5373.

[0057] The reactivated catalyst contains residual sulfur (before optional sulfidation) in a content of less than 5% by weight, preferably from 0.1% to 4.9% by weight, and more preferably from 0.1% to 2.0% by weight, and particularly preferably from 0.2% to 0.8% by weight, relative to the total weight of the regenerated catalyst. The reactivated catalyst may also not contain residual sulfur.

[0058] The residual sulfur content in the reactivated catalyst was measured by elemental analysis according to ASTM D5373.

[0059] Optionally, the reactivated catalyst may additionally have low levels of contaminants such as silicon, arsenic, or chlorine generated from the feed processed by the fresh catalyst (which produces the at least partially deactivated catalyst).

[0060] Preferably, the silicon content (in addition to silicon that may be present on fresh catalyst) is less than 2% by weight, very preferably less than 1% by weight, relative to the total weight of the catalyst for reactivation.

[0061] Preferably, the arsenic content is less than 2000 ppm by weight, and very preferably less than 500 ppm by weight, relative to the total weight of the catalyst for restoring activity.

[0062] Preferably, the chlorine content is less than 2000 ppm by weight, and very preferably less than 500 ppm by weight, relative to the total weight of the catalyst for restoring activity.

[0063] The catalyst for restoring activity also contains an organic compound containing oxygen and / or nitrogen and / or sulfur. Typically, the organic compound is selected from compounds containing one or more chemical functional groups, or compounds including a furan ring, or sugars, wherein the chemical functional groups are selected from carboxylic acids, alcohols, thiols, thioethers, sulfones, sulfoxides, ethers, aldehydes, ketones, esters, carbonates, amines, nitriles, imides, oximes, ureas, and amides.

[0064] Oxygen-containing organic compounds may be selected from compounds containing one or more of the following chemical functional groups: carboxylic acids, alcohols, ethers, aldehydes, ketones, esters or carbonates, or may be compounds including a furan ring, or may be sugars. For example, the oxygen-containing organic compound can be one or more selected from the following compounds: 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-ketovalerate, di(C1-C4) alkyl succinate, more particularly dimethyl succinate, methyl acetoacetate, ethyl acetoacetate, 2-methoxyethyl 3-oxobutyrate, 2-methacryloyloxyethyl 3-oxobutyrate. Dibenzofuran, crown ether, phthalic acid, glucose, fructose, sucrose, sorbitol, xylitol, γ-valerolactone, 2-acetylbutyrolactone, propylene carbonate, 2-furfural (also known as furfural), 5-hydroxymethylfurfural (also known as 5-(hydroxymethyl)-2-furfural or 5-HMF), 2-acetylfuran, 5-methyl-2-furfural, methyl 2-furoate, furfuryl alcohol (also known as furfuryl alcohol), furfuryl acetate, ascorbic acid, butyl lactate, butyl butyryl lactate, ethyl 3-hydroxybutyrate, ethyl 3-ethoxypropionate, methyl 3-methoxypropionate, 2-ethoxyethyl acetate, 2-butoxyethyl acetate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and 5-methyl-2(3H)-furanone.

[0065] Nitrogen-containing organic compounds can be one or more selected from compounds containing one or more chemical functional groups selected from amine or nitrile functional groups. For example, nitrogen-containing organic compounds can be one or more selected from ethylenediamine, diethylenetriamine, hexamethylenediamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, acetonitrile, octylamine, guanidine, and carbazole.

[0066] The oxygen- and nitrogen-containing organic compound can be selected from one or more compounds containing one or more chemical functional groups, said chemical functional groups being selected from carboxylic acids, alcohols, ethers, aldehydes, ketones, esters, carbonates, amines, nitriles, imides, amides, ureas, or oxime functional groups. For example, the oxygen- and nitrogen-containing organic compound can be selected from one or more of the following compounds: 1,2-cyclohexanediaminetetraacetic acid, monoethanolamine (MEA), 1-methyl-2-pyrrolidone, dimethylformamide, ethylenediaminetetraacetic acid (EDTA), alanine, glycine, nitrotriacetic acid (NTA), N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid (HEDTA), diethylenetriaminepentaacetic acid (DTPA), tetramethylurea, glutamic acid, dimethyl... Dioxime, N,N-dihydroxyethylglycine, tris(hydroxymethyl)methylglycine, 2-methoxyethyl cyanoacetate, 1-ethyl-2-pyrrolidone, 1-vinyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolinone, 1-(2-hydroxyethyl)-2-pyrrolidone, 1-(2-hydroxyethyl))-2,5-pyrrolidone, 1-methyl-2-piperidinone, 1-acetyl-2-azacycloheptanone, 1-vinyl-2-azacycloheptanone, and 4-aminobutyric acid.

[0067] Sulfur-containing organic compounds can be selected from one or more compounds containing one or more chemical functional groups selected from: thiols, thioethers, sulfones, or sulfoxides. For example, sulfur-containing organic compounds can be selected from one or more of thioglycolic acid, 2,2'-thiodiethanol, 2-hydroxy-4-methylthiobutyric acid, sulfone derivatives or sulfoxide derivatives of benzothiophene, methyl 3-(methylthio)propionate, and ethyl 3-(methylthio)propionate.

[0068] Preferably, the organic compound contains oxygen; preferably, it is selected from γ-valerol, 2-acetylbutyrolactone, triethylene glycol, diethylene glycol, ethylene glycol, EDTA, maleic acid, malonic acid, citric acid, gluconic acid, dimethyl succinate, glucose, fructose, sucrose, sorbitol, xylitol, γ-ketovalerate, dimethylformamide, 1-methyl-2-pyrrolidone, propylene carbonate, 2-methoxyethyl 3-oxobutyrate, N,N-dihydroxyethylglycine, tris(hydroxymethyl)methylglycine, 2-furfural (also known as furfural), 5-hydroxymethylfurfural (also known as... 5-(hydroxymethyl)-2-furfural (or 5-HMF), 2-acetylfuran, 5-methyl-2-furfural, ascorbic acid, butyl lactate, ethyl 3-hydroxybutyrate, ethyl 3-ethoxypropionate, 2-ethoxyethyl acetate, 2-butoxyethyl acetate, 2-hydroxyethyl acrylate, 1-vinyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolinone, 1-(2-hydroxyethyl)-2-pyrrolidone, 1-(2-hydroxyethyl)-2,5-pyrrolidone, 5-methyl-2(3H)-furanone, 1-methyl-2-piperidinone, and 4-aminobutyric acid.

[0069] The content of one or more oxygen- and / or nitrogen- and / or sulfur-containing organic compounds on the reactivated catalyst is from 1% to 30% by weight, preferably from 1.5% to 25% by weight, more preferably from 2% to 20% by weight, relative to the total weight of the reactivated catalyst.

[0070] Method for preparing this catalyst with restored activity The reactivated catalyst is generated from at least partially deactivated catalyst, which itself is generated from fresh catalyst. More specifically, the reactivated catalyst is prepared from at least partially deactivated catalyst obtained by a hydrotreating process, and preferably by a hydrodesulfurization process for sulfur-containing olefin gasoline fractions. The at least partially deactivated catalyst comprises at least one Group VIII metal, at least one Group VIb metal, an oxide support, and optionally phosphorus. The reactivation method includes the following steps: a) The at least partially degraded catalyst is regenerated in an oxygen-containing stream at a temperature of 350°C to 550°C to obtain a regenerated catalyst. b) Contact at least one organic compound containing oxygen and / or nitrogen and / or sulfur with the regenerated catalyst. c) The drying step is carried out at a temperature below 200°C without subsequent calcination to obtain a catalyst with restored activity.

[0071] It is important to emphasize that the catalyst for restoring activity, in its preparation method, is not calcined after the introduction of an organic compound containing oxygen and / or nitrogen and / or sulfur, so as to retain the organic compound at least partially in the catalyst. Here, calcination is understood to refer to heat treatment at a temperature greater than or equal to 200°C in a gas containing air or oxygen.

[0072] Additionally, during step b), no compound of Group VIb metal, no compound of Group VIII metal, or no phosphorus compound is added to the regenerated catalyst.

[0073] The preparation of fresh catalysts is known and typically involves impregnating a Group VIII or Group VIb metal and optionally a phosphorus and / or organic compound onto an oxide support, followed by a drying operation and then optionally calcination, which allows for the acquisition of an active phase in its oxide form. Before using the fresh catalyst in a method for hydrodesulfurizing sulfur-containing olefin gasoline fractions, it is typically sulfided to form the active phase described below.

[0074] According to an alternative form of the invention, the fresh catalyst is not calcined during its preparation, that is, the impregnated catalyst precursor does not undergo a heat treatment step at a temperature above 200°C, in an inert atmosphere or in an oxygen-containing atmosphere, with or without water.

[0075] According to another preferred alternative form of the invention, the fresh catalyst has undergone a calcination step during its preparation; that is, the impregnated catalyst precursor has been subjected to a heat treatment step at a temperature of 200°C to 1000°C, preferably 250°C to 750°C, typically for a period of 15 minutes to 10 hours, in an inert or oxygen-containing atmosphere, with or without water. This is because it has been noted that the activity reduction exhibited by a fresh catalyst that has undergone a calcination step (during the preparation of the fresh catalyst) is smaller than that exhibited by a fresh catalyst that has not undergone a calcination step (during the preparation of the fresh catalyst).

[0076] The preparation of the reactivated catalyst includes step a) (regeneration step) to remove coke and sulfur. This is because, according to step a), the at least partially deactivated catalyst is regenerated in an oxygen-containing stream at a temperature of 350°C to 550°C to obtain a regenerated catalyst.

[0077] Even if this is possible, regeneration is preferably not carried out by keeping the supported catalyst in the hydrotreatment reactor (in-situ regeneration). Preferably, the catalyst, thus at least partially depleted, is extracted from the reactor and sent to a regeneration unit for regeneration (non-in-situ regeneration).

[0078] Preferably, a deoiling step precedes regeneration step a). The deoiling step typically involves contacting at least partially degraded catalyst with an inert gas stream (i.e., substantially oxygen-free) at a temperature of 300°C to 400°C, preferably 300°C to 350°C, for example, in a nitrogen atmosphere. The inert gas flow rate (based on flow rate / unit volume catalyst) is 5 to 150 s1.1 -1 .h -1 It lasts for 3 to 7 hours.

[0079] In an alternative form, the deoiling step can be carried out with light hydrocarbons, via steam treatment or any other similar method.

[0080] The deoiling step allows the removal of soluble hydrocarbons and thus releases the porosity of the catalyst, which is at least partially deactivated and required to restore its activity.

[0081] Regeneration step a) is typically carried out over an oxygen-containing stream, usually air. The water content is typically from 0% to 50% by weight. The gas flow rate (based on the flow rate per unit volume of at least partially depleted catalyst) is preferably from 20 to 2000 sl. -1 .h -1 More preferably 30 to 1000 Sl.1 -1 .h -1 40-500 Sl.1 is particularly preferred. -1 .h -1 The regeneration duration 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 depleted catalysts is typically carried out at temperatures between 350°C and 550°C, preferably between 360°C and 500°C.

[0082] Following the regeneration step, the regenerated catalyst intended for use in the hydrodesulfurization method according to the invention undergoes a reactivation step b), in which at least one oxygen- and / or nitrogen- and / or sulfur-containing organic compound, as described above, is contacted with the regenerated catalyst. The role of the organic compound, compared to an unadded catalyst, is to enhance catalytic activity.

[0083] In this case, the molar ratio of the added organic compound to the Group VIb metal already present in the regenerated catalyst is 0.01 to 5 mol / mol, preferably 0.05 to 3 mol / mol, more preferably 0.05 to 2 mol / mol, and very preferably 0.1 to 1.5 mol / mol.

[0084] When multiple organic compounds are present, different molar ratios are suitable for each of the present organic compounds.

[0085] Step b) of contacting the regenerated catalyst with an impregnation solution containing a mixture (which contains an organic compound containing oxygen and / or nitrogen and / or sulfur) can be carried out by slurry impregnation, or by over-impregnation, or by dry impregnation, or by any other means known to those skilled in the art.

[0086] Equilibrium (or excess) impregnation involves immersing the support or catalyst in a solution with a volume greater than (usually significantly greater than) the pore volume of the support or catalyst while maintaining system agitation to improve exchange between the solution and the support or catalyst. Equilibrium is eventually reached after different substances diffuse into the pores of the support or catalyst. The amount of deposited element is controlled by pre-measuring an adsorption isotherm, which correlates the concentration of the element to be deposited in the solution with the amount of element deposited on the solid at equilibrium.

[0087] Dry impregnation, by definition, involves introducing an impregnation solution whose volume is equal to the pore volume of the support or catalyst. Dry impregnation allows all additives contained in the impregnation solution to be deposited on a given support or catalyst.

[0088] Step b) can be advantageously carried out by impregnating the regenerated catalyst with the impregnation solution once or multiple times with an excess solution, or preferably by one or more times with a dry impregnation, and very preferably by a single dry impregnation.

[0089] The organic compound is preferably dissolved in an aqueous solution and then impregnated onto the catalyst.

[0090] Preferably, the impregnation solution consists of a solvent and an organic compound.

[0091] During step b), when the regenerated catalyst is contacted with an impregnation solution containing the blend, no compound of Group VIb metals and / or Group VIII metals and / or phosphorus is added, the blend comprising an organic compound containing oxygen and / or nitrogen and / or sulfur.

[0092] The impregnation solution may contain any polar solvent known to those skilled in the art. The polar solvent used is advantageously selected from methanol, ethanol, water, phenol, and cyclohexanol, used alone or in mixtures. The polar solvent may also be advantageously selected from propylene carbonate, DMSO (dimethyl sulfoxide), N-methylpyrrolidone (NMP), and sulfolane, used alone or in mixtures. Preferably, a polar protic solvent is used. A list of commonly used polar solvents and their dielectric constants can be found in the book […]. Solvents and Solvent Effects in Organic Chemistry The reference can be found in C. Reichardt, Wiley-VCH, 3rd edition, 2003, pp. 472-474. Very preferably, the solvent used is water or ethanol, and particularly preferably water. In one possible embodiment, the solvent may be absent from the impregnation solution.

[0093] Advantageously, the impregnated carrier is aged after each impregnation step. Aging allows the impregnation solution to be uniformly dispersed within the carrier.

[0094] Any curing step is advantageously carried out at atmospheric pressure, in a water-saturated atmosphere, and at a temperature of 17°C to 50°C, preferably at ambient temperature. Typically, a curing time of ten minutes to forty-eight hours, preferably thirty minutes to six hours, is sufficient.

[0095] After the reactivation step, the reactivated catalyst is dried at a temperature below 200°C, advantageously between 50°C and 180°C, preferably between 70°C and 150°C, and most preferably between 75°C and 130°C.

[0096] The drying step is preferably carried out under an inert or oxygen-containing atmosphere. The drying step can be performed using any technique known to those skilled in the art. Advantageously, it is carried out at atmospheric pressure or under reduced pressure. Preferably, the step is carried out at atmospheric pressure. Advantageously, it is carried out in a traversed bed using hot air or any other hot gas. Preferably, when drying is carried out in a fixed bed, the gas used is air or an inert gas, such as argon or nitrogen. Very preferably, drying is carried out in a traversed bed in the presence of nitrogen and / or air. Preferably, the duration of the drying step is from 5 minutes to 15 hours, more preferably from 30 minutes to 12 hours.

[0097] According to the first alternative, drying is carried out to preferably maintain at least 30% by weight of the organic compound introduced during the impregnation step; preferably, this amount is greater than 50% by weight, more preferably greater than 70% by weight, calculated based on the carbon remaining on the reactivated catalyst.

[0098] At the end of the drying step, the catalyst is now reactivated and will undergo an optional activation (sulfidation) step so that it can be subsequently used in the hydrodesulfurization process of gasoline.

[0099] Before contacting the feedstock to be treated in the hydrodesulfurization method for gasoline according to the invention, the reactivated catalyst typically undergoes a sulfidation step. Sulfidation is preferably carried out in a sulfur-reducing medium, i.e., in the presence of H2S and hydrogen, to convert metal oxides into sulfides, such as, for example, MoS2 and Co9S8. Sulfidation is carried out by injecting a feed stream containing H2S and hydrogen, or a sulfur compound capable of decomposing to produce H2S, onto the catalyst in the presence of the catalyst and hydrogen. Polysulfides, such as dimethyl disulfide (DMDS), are commonly used H2S precursors for sulfide catalysts. Sulfur can also be derived from the feedstock. The temperature is adjusted to allow H2S to react with the metal oxide to form metal sulfides. This sulfidation can be carried out at temperatures from 200°C to 600°C, more preferably from 300°C to 500°C, in situ or ex-situ (inside or outside the reactor) of the reactor according to the method of the invention.

[0100] The hydrodesulfurization method according to the present invention involves contacting a sulfur-containing olefin gasoline fraction with a reactivated catalyst and hydrogen under the following conditions: -At a temperature of 200°C to 400°C, preferably 230°C to 330°C, - Under a total pressure of 1-3 MPa, preferably 1.5-2.5 MPa, - for 1-10h -1 Preferred 2-6h -1 The space-time velocity (HSV) is defined as the feed volume flow rate relative to the catalyst volume. - A hydrogen / gasoline feed volume ratio of 100 to 1200 Sl / l, preferably 150 to 400 Sl / l.

[0101] The hydrodesulfurization method according to the present invention is carried out in the presence of a reactivated catalyst. It can also be carried out in the presence of a mixture of a reactivated catalyst and a fresh or regenerated catalyst.

[0102] When a fresh or regenerated catalyst is available, it comprises at least one Group VIII metal, at least one Group VIb metal and an oxide support, and optionally phosphorus and / or organic compounds as described above.

[0103] The active phase and support of a fresh or regenerated catalyst may be the same as or different from those of a catalyst whose activity has been restored.

[0104] The active phase and support of a fresh catalyst may be the same as or different from those of a regenerated catalyst.

[0105] When hydrodesulfurization is carried out in the presence of a reactivated catalyst and a fresh or regenerated catalyst, it can be carried out in a fixed-bed reactor containing multiple catalyst beds.

[0106] In this case, and according to the first alternative form, in the direction of feed circulation, the catalyst bed containing fresh or regenerated catalyst can precede the catalyst bed containing reactivated catalyst.

[0107] In this case, and according to the second alternative form, in the direction of feed circulation, the catalyst bed containing the reactivated catalyst can precede the catalyst bed containing the fresh or regenerated catalyst.

[0108] In this case, and according to the third alternative form, the catalyst bed may contain a mixture of a reactivated catalyst and a fresh catalyst and / or a regenerated catalyst.

[0109] In these cases, the operating conditions are those described above. They are generally the same in different catalytic beds except for temperature, which typically increases in the catalytic bed due to the exothermic nature of the hydrodesulfurization reaction.

[0110] When a hydrodesulfurization process is carried out in the presence of a restored catalyst and a fresh or regenerated catalyst in multiple fixed-bed or fluidized-bed reactors connected in series, one reactor may contain the restored catalyst while another reactor may contain a fresh or regenerated catalyst, or a mixture of the restored catalyst and fresh and / or regenerated catalyst, and these can be in any order. An apparatus for removing H2S from the effluent produced by a first hydrodesulfurization reactor (before the effluent is treated in a second hydrodesulfurization reactor) can be provided. In these cases, the operating conditions are as described above, and may be the same or different in different reactors.

[0111] Selective hydrogenation (optional step) According to an alternative form, the gasoline fraction is subjected to a selective hydrogenation step prior to the hydrodesulfurization method according to the invention.

[0112] Preferably, the gasoline processed by the hydrodesulfurization method according to the invention is heavy gasoline produced by a distillation step, which is designed to separate a wide range of gasoline fractions produced by a cracking method (or FRCN, for “full-range cracked naphtha”) into light gasoline and heavy gasoline.

[0113] Advantageously, the wide FRCN fraction undergoes a selective hydrogenation step as described below prior to the distillation step.

[0114] The FRCN fraction is pretreated in the presence of hydrogen and a selective hydrogenation catalyst to at least partially hydrogenate the diene and carry out a reaction that increases the molecular weight of a portion of the thiol (RSH) compounds present in the feed (to generate thioethers by reacting with olefins).

[0115] For this purpose, the broad FRCN fraction is fed into a selective hydrogenation catalytic reactor comprising at least one fixed or mobile catalyst bed for the selective hydrogenation of dienes and for increasing the molecular weight of thiols. The selective hydrogenation of dienes and the reaction for increasing the molecular weight of thiols are preferably carried out on a sulfidation catalyst comprising at least one Group VIII element and optionally at least one Group VIb element and an oxide support. The Group VIII element is preferably selected from nickel and cobalt, especially nickel. When a Group VIb element is present, it is preferably selected from molybdenum and tungsten, with molybdenum being highly preferred.

[0116] The oxide support for the catalyst is preferably selected from alumina, nickel aluminate, silica, silicon carbide, or mixtures of these oxides. Alumina is preferred, and high-purity alumina is more preferred. According to a preferred embodiment, the selective hydrogenation catalyst comprises nickel with a weight content of 1%-12% nickel oxide (in the form of NiO) and molybdenum with a weight content of 6%-18% molybdenum oxide (in the form of MoO3), and the nickel / molybdenum molar ratio is 0.3-2.5, wherein the metal is deposited on a support composed of alumina, and wherein the degree of sulfidation of the metal constituting the catalyst is greater than 50%.

[0117] During the optional selective hydrotreating step, gasoline is contacted with the catalyst at a temperature of 50°C to 250°C, preferably 80°C to 220°C, and more preferably 90°C to 200°C, with a liquid-space velocity (LHSV) of 0.5 h⁻¹. -1 -20h -1 Liquid air velocity is measured in liters per liter of catalyst per hour (L / Lh). The pressure is 0.4 MPa-5 MPa, preferably 0.6-4 MPa, and even more preferably 1-2 MPa. Optional selective hydrogenation steps are typically used at 2-100 Sm. 3 hydrogen / m 3 Feed, preferably 3-30Sm 3 hydrogen / m 3 The H2 / gasoline feed ratio is implemented. Example

[0118] Example 1 - Preparation of Regenerated Catalyst A (Comparative) The support for the fresh catalyst is a type with a thickness of 140m. 2 The specific surface area per g is 1.0 cm². 3 / g pore volume of transition alumina. Fresh catalyst was prepared by dry impregnation of the support with an aqueous solution of ammonium heptamolybdate and cobalt nitrate, the volume of the solution containing the metal precursor being exactly equal to the pore volume of the support bulk. The concentration of the metal precursor in the aqueous solution was adjusted to obtain the desired weight percentage of molybdenum and cobalt on the final catalyst. After dry impregnation on the support, the catalyst was aged in a water-saturated 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.

[0119] The fresh catalyst obtained after calcination has a molybdenum (MoO3 equivalent) content of 7.4 wt% and a cobalt (CoO equivalent) content of 2.0 wt%. The catalyst has a Co / Mo atomic ratio of 0.52.

[0120] Fresh catalyst was used for desulfurization of catalytic cracking (FCC) gasoline, the characteristics of which are listed in Table 1. The reaction was carried out for 900 hours at 270°C in a transverse bed reactor under the following conditions: P = 2 MPa, HSV = 4 h⁻¹. -1 The H2 / HC ratio was 300 L / L hydrocarbon feed. The catalyst was pretreated at 350 °C with a feed containing 4% by weight of sulfur in the form of DMDS (dimethyl disulfide) to sulfide the oxide phase. The reaction was carried out in an isothermal pilot reactor with an upward feed flow.

[0121] Table 1: Characteristics of FCC gasoline fractions used for aging fresh catalysts Aromatics wt% 41.3 paraffin wt% 27.2 cycloalkanes wt% 11.0 olefins wt% 20.5 T5℃ 62 T95℃ 225 .

[0122] After the hydrodesulfurization of the catalytic cracking (FCC) gasoline is completed, the degraded catalyst is removed from the reactor. The degraded catalyst is then washed with toluene in a Soxhlet at 250°C for 7 hours.

[0123] The regeneration of the depleted / washed catalyst was then carried out in a tubular oven at 450°C under dry air for 2 hours to obtain regenerated catalyst A. The residual carbon content of catalyst A is zero.

[0124] Example 2 - Preparation of Regenerated Catalyst B (Comparative) The support for catalyst B is a transition alumina with a specific surface area of ​​205 m². 3 / g, pore volume 0.8cm³ 3 / g. Fresh catalyst was prepared by dry impregnation of a support with an aqueous solution of molybdenum oxide, cobalt hydroxide, and orthophosphoric acid, the volume of the solution containing the metal precursors being strictly equal to the pore volume of the support bulk. The concentration of the metal precursors in the aqueous solution was adjusted to obtain the desired weight percentages of molybdenum, cobalt, and phosphorus on the final catalyst. After dry impregnation on the support, the catalyst was aged in a water-saturated chamber for 1 hour and 30 minutes, dried in air at 90°C for 12 hours in an oven, and then calcined in air at 450°C for 2 hours.

[0125] The fresh catalyst obtained after calcination has a content of 15.2 wt% molybdenum (MoO3 equivalent), 2.9 wt% cobalt (CoO equivalent), and 2.5 wt% phosphorus (P2O5 equivalent). The catalyst has a Co / Mo atomic ratio of 0.37 and a P / Mo atomic ratio of 0.33.

[0126] Desulfurization of catalytic cracking (FCC) gasoline was performed using a fresh catalyst. The properties of this gasoline are listed in Table 1. The reaction was carried out in a transverse bed reactor at 270°C for 900 hours under the following conditions: P = 2 MPa, HSV = 4 h. -1 The H2 / HC ratio was 300 L / L hydrocarbon feed. The catalyst was pretreated at 350 °C with a feed containing 4% by weight of sulfur in the form of DMDS (dimethyl disulfide) to provide sulfidation of the oxide phase. The reaction was carried out in an isothermal pilot reactor in an upward flow.

[0127] At the end of the hydrodesulfurization process of the aforementioned catalytic cracking (FCC) gasoline, the depleted catalyst was removed from the reactor. The depleted catalyst was then washed with toluene in a Soxhlet extractor at 250°C for 7 hours (deoiling).

[0128] The depleted / washed catalyst was then regenerated in a tube oven at 450°C in dry air for 2 hours to obtain regenerated catalyst B. The residual carbon content of regenerated catalyst B was 0.3% by weight.

[0129] Example 3 - Preparation of catalysts A1 and A2 with restored activity by adding citric acid (according to the present invention) Catalyst A1 was prepared by dry impregnation of regenerated catalyst A with an aqueous citric acid solution, the volume of which was strictly equal to the pore volume of the catalyst A bulk. The concentration of citric acid in the aqueous solution was adjusted to obtain a molar ratio of 0.2 mol / mol citric acid to molybdenum already present on the regenerated catalyst A. After dry impregnation on the regenerated catalyst A, catalyst A1 was aged in a water-saturated chamber for 1 hour and 30 minutes, and then dried in air at 90°C in an oven for 12 hours.

[0130] Catalyst A2 was obtained in a similar manner, but using an aqueous solution of citric acid, the concentration of which was adjusted to obtain a molar ratio of citric acid to molybdenum already present on the regenerated catalyst A of 1.

[0131] Example 4 - Preparation of catalyst A3 with restored activity by adding ascorbic acid (according to the present invention) Catalyst A3 was prepared by dry impregnation of regenerated catalyst A with an aqueous ascorbic acid solution, the volume of which was strictly equal to the pore volume of the regenerated catalyst A. The concentration of ascorbic acid in the aqueous solution was adjusted to obtain a molar ratio of ascorbic acid to molybdenum already present on the regenerated catalyst A of 0.8 mol / mol. After dry impregnation on the regenerated catalyst A, catalyst A3 was aged in a water-saturated chamber for 1 hour and 30 minutes, and then dried in air at 120°C in an oven for 12 hours.

[0132] Example 5 - Preparation of regenerated catalyst A4 by adding triethylene glycol (according to the present invention) Catalyst A4 was prepared by dry impregnation of regenerated catalyst A with an aqueous triethylene glycol solution, the volume of which was strictly equal to the pore volume of the regenerated catalyst A bulk. The concentration of triethylene glycol in the aqueous solution was adjusted to obtain a molar ratio of triethylene glycol to molybdenum already present on the regenerated catalyst A of 0.6 mol / mol. After dry impregnation on the regenerated catalyst A, catalyst A4 was aged in a water-saturated chamber for 1 hour and 30 minutes, and then dried in air at 160°C in an oven for 12 hours.

[0133] Example 6 - Preparation of catalyst A5 with restored activity by adding citric acid and urea (according to the present invention) Catalyst A5 was prepared by dry impregnation of regenerated catalyst A with an aqueous solution of citric acid and urea, the volume of which was strictly equal to the pore volume of the regenerated catalyst A bulk. The concentrations of citric acid and urea in the aqueous solution were adjusted to obtain molar ratios of 0.3 and 1.5 of citric acid and urea to the molybdenum already present on the regenerated catalyst A. After dry impregnation on the regenerated catalyst A, catalyst A5 was aged in a water-saturated chamber for 1 hour and 30 minutes, and then dried in an oven at 110°C in air for 12 hours.

[0134] Example 7 - Preparation of catalyst B1 with restored activity by adding diethanolamine (according to the present invention) Catalyst B1 was prepared by dry impregnation of regenerated catalyst B with an aqueous solution of diethanolamine, the volume of which was strictly equal to the pore volume of the regenerated catalyst B. The concentration of diethanolamine in the aqueous solution was adjusted to obtain a molar ratio of 2.1 mol / mol diethanolamine to molybdenum already present on the regenerated catalyst B. After dry impregnation on the regenerated catalyst B, catalyst B1 was aged in a water-saturated chamber for 1 hour and 30 minutes, and then dried in air at 110°C in an oven for 12 hours.

[0135] Example 8 - Preparation of catalyst B2 with restored activity by adding citric acid and γ-ketovalerate (according to this invention) bright) Catalyst B2 was prepared by dry impregnation of regenerated catalyst B with an aqueous solution of citric acid and γ-ketovalerate, the volume of which was strictly equal to the pore volume of the regenerated catalyst B bulk. The concentrations of citric acid and γ-ketovalerate in the aqueous solution were adjusted to obtain ratios of 0.5 and 0.8 moles of citric acid and γ-ketovalerate to the moles of molybdenum already present on the regenerated catalyst B. After dry impregnation on the regenerated catalyst B, catalyst B2 was aged in a water-saturated chamber for 1 hour and 30 minutes and then dried in air at 110°C in an oven for 12 hours.

[0136] Example 9 - Evaluation of the catalytic performance of catalysts A, A1, A2, A3, A4, and A5 A representative model feed of catalytic cracking (FCC) gasoline was used to evaluate the catalytic performance of various catalysts. This model feed contained 10 wt% 2,3-dimethylbut-2-ene and 0.33 wt% 3-methylthiophene (i.e., 1000 ppm sulfur in the feed). The solvent used was heptane.

[0137] Hydrodesulfurization (HDS) was carried out in a fixed transverse bed reactor at a total pressure of 1.5 MPa and a temperature of 210 °C, with an HSV of 6 h⁻¹. -1 (HSV = feed volumetric flow rate / catalyst volume) and carried out in the presence of 4 ml catalyst, with an H2 / feed volume ratio of 300 Sl / l. Prior to the HDS reaction, the catalyst was in-situ sulfided at 350 °C under atmospheric pressure for 2 hours in a hydrogen stream containing 15 mol% H2S.

[0138] Each catalyst was sequentially added to the reactor. Samples were taken at different time intervals and analyzed by gas chromatography to observe the disappearance of reactants and the formation of products.

[0139] The catalytic performance of the catalysts was evaluated in terms of catalytic activity and selectivity. Hydrodesulfurization (HDS) activity was represented by the rate constant (kHDS) of the HDS reaction of 3-methylthiophene, normalized by the introduced catalyst volume, and assumed to be first-order kinetics with respect to sulfur compounds. The hydrogenation activity of olefins (HydO) was represented by the rate constant of the hydrogenation reaction of 2,3-dimethylbut-2-ene, normalized by the introduced catalyst volume, and assumed to be first-order kinetics with respect to olefins.

[0140] The selectivity of the catalyst is represented by the normalized ratio of the rate constant, kHDS / kHydO. As the catalyst becomes more selective, the kHDS / kHydO ratio increases. The obtained values ​​are normalized by using catalyst A as a reference (relative HDS activity and relative selectivity equal to 100). Therefore, the performance quality is relative to both HDS activity and relative selectivity.

[0141] Table 2 catalyst Relative HDS activity Relative selectivity A (Comparison) 100 100 A1 (according to the present invention) 109 106 A2 (according to the present invention) 115 108 A3 (according to the present invention) 112 116 A4 (according to the present invention) 120 110 A5 (according to the present invention) 122 113 .

[0142] The reactivated catalysts A1, A2, A3, A4 and A5 exhibited improved activity and selectivity for olefin hydrogenation in hydrodesulfurization, which were higher than those of the control catalyst A (regenerated).

[0143] This improvement in catalyst selectivity is particularly advantageous in the case of hydrodesulfurization methods for olefin-containing gasoline (for which attempts are made to limit octane loss due to olefin hydrogenation as much as possible).

[0144] Example 10 - Evaluation of the catalytic performance of catalysts B, B1, and B2 Catalysts B (comparative), B1, and B2 (according to the present invention) were tested under the conditions described in Example 9 above.

[0145] Table 3 catalyst Relative HDS activity Relative selectivity B (Comparison) 100 100 B1 (according to the present invention) 112 111 B2 (according to the present invention) 119 115 .

[0146] The reactivated catalysts B1 and B2 exhibited improved activity and selectivity for olefin hydrogenation in hydrodesulfurization, which were higher than those of the control catalyst B (regenerated).

[0147] This improvement in catalyst selectivity is particularly advantageous in hydrodesulfurization processes for olefin-containing gasoline (for which the aim is to limit octane loss as much as possible due to olefin hydrogenation).

[0148] Example 11 - Preparation of Regenerated Catalyst C (Comparative) The support for the fresh catalyst was transition alumina with a specific surface area of ​​140 m² / g and a pore volume of 1.0 cm³ / g. The fresh catalyst was prepared by dry impregnation of the support with an aqueous solution of ammonium heptamolybdate and cobalt nitrate, the volume of the solution containing the metal precursors being strictly equal to the pore volume of the bulk support. The concentration of the metal precursors in the aqueous solution was adjusted to obtain the desired weight percentages of molybdenum and cobalt on the final catalyst. After dry impregnation on the support, the catalyst was aged in a water-saturated chamber for 1 hour and 30 minutes, dried in air at 90°C for 12 hours in an oven, and then calcined in air at 450°C for 2 hours.

[0149] The fresh catalyst obtained after calcination has a molybdenum content of 10.4 wt% (MoO3 equivalent) and a cobalt content of 3.1 wt% (CoO equivalent). The Co / Mo atomic ratio of the catalyst is 0.57.

[0150] Desulfurization of catalytic cracking (FCC) gasoline was performed using a fresh catalyst; the characteristics of this gasoline are listed in Table 1. The reaction was carried out for 900 hours at 270°C in a transverse bed reactor under the following conditions: P = 2 MPa, HSV = 4 h⁻¹. -1 The H2 / HC ratio was 300 L / L hydrocarbon feed. The catalyst was pretreated at 350 °C with a feed containing 4% by weight of sulfur in the form of DMDS (dimethyl disulfide) to provide sulfidation of the oxide phase. The reaction was carried out in an isothermal pilot reactor in an upward flow.

[0151] Table 4 S ppm 392 Aromatics wt% 41.3 paraffin wt% 27.2 cycloalkanes wt% 11.0 olefins wt% 20.5 T5℃ 62 T95℃ 225 .

[0152] At the end of the hydrodesulfurization process of the aforementioned catalytic cracking (FCC) gasoline, the spent catalyst was removed from the reactor. The spent catalyst was then washed with toluene in a Soxhlet extractor at 250°C for 7 hours.

[0153] The regeneration of the exhausted / washed catalyst was then carried out in a tube oven at 450°C in dry air for 2 hours to obtain regenerated catalyst C.

[0154] Example 12 - Preparation of revitalized catalysts C1 and C2 by adding citric acid (according to the present invention) Catalyst C1 was prepared by dry impregnation of regenerated catalyst C with an aqueous citric acid solution, the volume of which was strictly equal to the pore volume of the catalyst C bulk. The concentration of citric acid in the aqueous solution was adjusted to obtain a molar ratio of 0.3 mol / mol citric acid to molybdenum already present on the regenerated catalyst C. After dry impregnation on the regenerated catalyst C, catalyst C1 was placed in a water-saturated chamber for 1 hour and 30 minutes, and then dried in air in an oven at 90°C for 12 hours. The specific surface area of ​​catalyst C1 was 127 m² / g, and the volume was 0.86 cm³ / g. The residual carbon and sulfur contents of catalyst C1 were 0.16 wt% and 0.59 wt%, respectively.

[0155] Catalyst C2 was obtained in a similar manner, but using an aqueous citric acid solution, the concentration of which was adjusted to obtain a molar ratio of citric acid to molybdenum already present on the regenerated catalyst C of 0.9. Catalyst C2 had a specific surface area of ​​130 m² / g and a volume of 0.86 cm³ / g. The residual carbon and sulfur contents of catalyst C2 were 0.19 wt% and 0.58 wt%, respectively.

[0156] Example 13 - Preparation of catalyst C3 with restored activity by adding ascorbic acid (according to the present invention) Catalyst C3 was prepared by dry impregnation of regenerated catalyst C with an aqueous ascorbic acid solution, the volume of which was strictly equal to the pore volume of the regenerated catalyst C. The concentration of ascorbic acid in the aqueous solution was adjusted to obtain a molar ratio of 0.5 mol / mol ascorbic acid to molybdenum already present on the regenerated catalyst C. After dry impregnation on the regenerated catalyst C, catalyst C3 was aged in a water-saturated chamber for 1 hour and 30 minutes and then dried in air in an oven at 120°C for 12 hours.

[0157] The catalyst C3 has a specific surface area of ​​127 m² / g and a volume of 0.86 cm³ / g. The residual carbon and sulfur contents of the catalyst C3 are 0.17 wt% and 0.59 wt%, respectively.

[0158] Example 14 - Preparation of a revitalized catalyst C4 by adding triethylene glycol (according to the present invention) Catalyst C4 was prepared by dry impregnation of regenerated catalyst C with an aqueous triethylene glycol solution, the volume of which was strictly equal to the pore volume of the regenerated catalyst C bulk. The concentration of triethylene glycol in the aqueous solution was adjusted to obtain a molar ratio of 0.6 mol / mol triethylene glycol to molybdenum already present on the regenerated catalyst C. After dry impregnation on the regenerated catalyst C, catalyst C4 was placed in a water-saturated chamber for 1 hour and 30 minutes, and then dried in air in an oven at 140°C for 12 hours.

[0159] The specific surface area of ​​catalyst C4 is 126 m² / g, and its volume is 0.86 cm³ / g. The residual carbon and sulfur contents of catalyst C4 are 0.16 wt% and 0.57 wt%, respectively.

[0160] Example 15 - Preparation of revitalized catalyst C5 (according to the present invention) by adding citric acid and urea. Catalyst C5 was prepared by dry impregnation of regenerated catalyst C with an aqueous solution of citric acid and urea, the volume of which was strictly equal to the pore volume of the regenerated catalyst C. The concentrations of citric acid and urea in the aqueous solution were adjusted to obtain ratios of 0.2 and 1.25 moles of citric acid and urea to the moles of molybdenum already present on the regenerated catalyst C, respectively. After dry impregnation on the regenerated catalyst C, catalyst C5 was aged in a water-saturated chamber for 1 hour and 30 minutes and then dried in air in an oven at 110°C for 12 hours.

[0161] Catalyst C5 has a specific surface area of ​​127 m² / g and a volume of 0.87 cm³ / g. The residual carbon and sulfur contents of catalyst C5 are 0.14 wt% and 0.59 wt%, respectively.

[0162] Example 16 - Evaluation of the catalytic performance of catalysts C, C1, C2, C3, C4, and C5 Catalysts C (comparative), C1, and C2 (according to the present invention) were tested under the conditions described in Example 9 above.

[0163] Table 5 catalyst Relative HDS activity Relative selectivity C (Comparison) C1 (according to the present invention) 107 105 C2 (according to the present invention) 111 111 C3 (according to the present invention) 112 108 C4 (according to the present invention) 122 116 C5 (according to the present invention) 118 114 .

[0164] The reactivated catalysts C1, C2, C3, C4, and C5 exhibited improved activity and selectivity in hydrodesulfurization (relative to olefin hydrogenation), which were higher than those of the comparative catalyst C (regenerated).

[0165] This improvement in catalyst selectivity is particularly advantageous in hydrodesulfurization methods for olefin-containing gasoline (for which attempts are made to limit octane loss due to olefin hydrogenation as much as possible).

Claims

1. A method for hydrodesulfurization of sulfur-containing olefin gasoline fractions, wherein the gasoline fraction, hydrogen, and a reactivating catalyst are contacted, the hydrodesulfurization method being carried out at a temperature of 200°C-400°C and a total pressure of 1-3 MPa for 1-10 h. -1 The experiment was carried out at a space-time velocity and a hydrogen / gasoline feed volume ratio of 100-1200 Sl / l, wherein the space-time velocity was defined as the feed volume flow rate relative to the catalyst volume. The reactivating catalyst was produced by a hydrotreating method and contained at least one Group VIII metal, at least one Group VIb metal, an oxide support, and at least one organic compound containing oxygen and / or nitrogen and / or sulfur. The reactivating catalyst contained less than 2% by weight of residual carbon and less than 5% by weight of residual sulfur relative to the total weight of the reactivating catalyst. The organic compound containing oxygen and / or nitrogen and / or sulfur was selected from γ-valerolactone, 2-acetylbutyrolactone, triethylene glycol, diethylene glycol, ethylene glycol, ethylenediaminetetraacetic acid, maleic acid, malonic acid, citric acid, gluconic acid, and di(C1-C4) succinate. Glucose, fructose, sucrose, sorbitol, xylitol, dimethylformamide, 1-methyl-2-pyrrolidone, propylene carbonate, 2-methoxyethyl 3-oxobutyrate, N,N-dihydroxyethylglycine, tris(hydroxymethyl)methylglycine, 2-furfural, 5-hydroxymethylfurfural, 2-acetylfuran, 5-methyl-2-furfural, ascorbic acid, butyl lactate, ethyl 3-hydroxybutyrate, ethyl 3-ethoxypropionate, 2-ethoxyethyl acetate, 2-butoxyethyl acetate, 2-hydroxyethyl acrylate, 1-vinyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolinone, 1-(2-hydroxyethyl)-2-pyrrolidone, 1-(2-hydroxyethyl)-2,5-pyrrolidone, 5-methyl-2(3H)-furanone, 1-methyl-2-piperidinone, and 4-aminobutyric acid.

2. The method according to the preceding claim, wherein, The group VIb metal content of the reactivated catalyst is from 1% to 40% by weight of the group VIb metal oxide relative to the total weight of the reactivated catalyst, and the group VIII metal content is from 0.1% to 10% by weight of the group VIII metal oxide relative to the total weight of the reactivated catalyst.

3. The method according to any one of the preceding claims, wherein, The reactivating catalyst also contains phosphorus, expressed as P2O5, in a phosphorus content of 0.3% to 10% by weight relative to the total weight of the reactivating catalyst, and the phosphorus / (Group VIb metal) molar ratio in the reactivating catalyst is 0.1 to 0.

7.

4. The method according to any one of the preceding claims, wherein the catalyst for restoring activity is characterized by a specific surface area of ​​20-200 m² / g, preferably 30-180 m² / g.

5. The method according to any one of the preceding claims, wherein, The oxide support for the catalyst that restores activity is selected from alumina, silica, silica-alumina, or titanium or magnesium oxide, used alone or as a mixture with alumina or silica-alumina.

6. The method according to any one of the preceding claims, wherein the reactivated catalyst is generated from a hydrodesulfurization method for sulfur-containing olefin gasoline fractions.

7. The method according to any one of the preceding claims, wherein the reactivated catalyst is subjected to a sulfidation step before or during the hydrodesulfurization process.

8. The method according to any one of the preceding claims, wherein the gasoline fraction is gasoline that produces an autocatalytic cracking unit.

9. The method according to any one of the preceding claims, wherein the method is carried out in a catalytic bed of a fixed-bed type reactor comprising a plurality of catalytic beds; and in the feed circulation direction, at least one other catalytic bed upstream or downstream of the catalytic bed comprising a reactivated catalyst comprises at least partially fresh catalyst and / or regenerated catalyst.

10. The method according to any one of the preceding claims, wherein the method is carried out in at least two reactors of the fixed-bed or fluidized-bed type connected in series; at least one of the reactors contains a reactivated catalyst, while the other reactor contains a fresh catalyst or a regenerated catalyst, or a mixture of a reactivated catalyst and fresh and / or regenerated catalyst, in any order, wherein at least a portion of H2S is removed or not removed from the effluent generated from the first reactor before the effluent generated from the first reactor is treated in the second reactor.

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