FR2627104A1 - Process for presulphurising a catalyst for processing hydrocarbons - Google Patents

Abstract

A process for treating a new or regenerated catalyst containing a support based on at least one oxide of a metal or of a metalloid and at least one active metal, carried out in the absence of hydrogen and consisting in treating the catalyst with the aid of at least one sulphurising agent employed in solution in a solvent. The invention is characterised in that the sulphurising agent is a polysulphide of general formula: where R is a linear or branched organic radical containing 2 to 12 carbon atoms, R' is an alkyl, alkenyl, arylalkyl or arylalkenyl radical containing 1 to 12 carbon atoms, R' optionally containing at least one heteroatom chosen from the group consisting of oxygen, nitrogen and sulphur, x has the value 1 to 4, and y has the value 1 to 8.

Description

The present invention relates to a method of presulfiding a catalyst for treating hydrocarbons and / or preconditioning a catalser to be subsequently presulfided.

It is often desirable to carry out a sulphurization (generally called "presulphurisation") of the metals used in the composition of certain hydrocarbon refining and / or hydroconversion catalysts, either when these catalysts are new or after the regeneration of these catalysts before to reuse them.

Presulphurization of the new or regenerated catalysts is thus desirable for the use of these catalysts in the refining reactions, for example the desulfurization or hydrodesulfurization reactions of various species, for example, catalytic cracking or steam cracking gasolines. it is appropriate, before use, to lower the sulfur content without modifying the octane number of these species or by modifying it as little as possible. Such desulfurization reactions, generally carried out in the presence of hydrogen, between 200 and 400 ° C., at a pressure of between, for example, 5 and 60 bar, with a space velocity (expressed in m 3 of liquid injected charge per m 3 of catalyst per hour) of between 0.5 and 15, with a partial pressure of 4 to 60 bar, the feed being for example a gasoline distilling generally between 30 and 2200C and may have a bromine number between 40 and 80 (9/100 g ), containing about 15 to 45%, by volume, of olefins (essentially monoolefins, minor amounts of diolefins) and 15 to 25% of aromatic hydrocarbons.

The catalyst used for this type of desulfurization or hydrodesulphurization contains a generally non-acidic support, for example an alumina or mixtures of alumina (US Pat. No. 4,334,982) or any other suitable support based on at least one oxide of a metal or metalloid (magnesia (USP 4 132 632, USP 4 140 626), silica, silica-aluminas, silica-magnesia, silica-fluorinated, borated aluminas, clays, coals, fluorinated aluminas) or these carrier mixtures can at least partly be in amorphous form or crystallized form (zeolites) and the catalyst additionally containing 0.2 to 30% of at least one active metal groups
VI, VIII or other selected for example from the group consisting of cobalt, molybdenum, nickel and tungsten (USP 3,732,155 and 3,804,748). A pair of two of these metals is generally used, for example one of the pairs cobalt-molybdenum, nickel-molybdenum, cobalt-tungsten, tungsten-molybdenum, cobalt-nickel, nickel-tungsten. It is still possible, for example, to use a noble metal of group VIII of the platinum family: Pt, Pd ... US 4,098,682.

Thus, before being used, the catalyst, new or regenerated, is generally subjected in the prior art to sulphurisation (presulphurization) carried out in the hydrodesulfurization reactor.

This sulphurization makes it possible to include in the catalyst, for example, approximately 50 to 110% of the stoichiometric quantities of sulfur calculated on the amounts of sulphide of formula, (according to the metals present),
Co9S8, Mo S2 'WS2 and Ni3 S2.

This sulphurization (presulphurization) is carried out, in the prior art, at a temperature close to or higher (thus greater than 1800 ° C. and more particularly above 250 ° C.) relative to the reaction temperature chosen for the hydrodé reaction. sulphurization, for a few hours, using a mixture of hydrogen sulphide generally diluted in hydrogen (proportion of hydrogen sulphide in hydrogen of the order of 0.5 to 5% by volume) with a adequate space velocity of the order, for example, from about 1,000 to 3,000 liters of gas under normal conditions of temperature and pressure per liter of catalyst per hour (USP 4,334,982) .Sulfuration (or presulfuration) itself may be carried out by temperature step (French Patent No. 2,476,118). Various sulphurizing agents, other than hydrogen sulphide (H 2 S) and for example a sulphide compound of the mercaptan family, carbon disulfide (CS 2), sulphides or disulfides, thiophenic compounds and preferably dimethylsulfide (DMS) and dimethyl disulphide (DMDS).

Sulfurization or presulphurization of regenerated catalyst is also desirable in the hydroreforming reactions of hydrocarbons (reforming, in particular, a naphtha) and production of aromatic hydrocarbons ("Aromizing"), for example the production of benzene, toluene and xylenes (ortho, meta or para), whether from unsaturated or unsaturated species (for example pyrolysis gasoline, cracking gasoline, in particular steam cracking gasoline, or catalytic reforming gasoline), or from naphthenic hydrocarbons capable of dehydrogenation to become aromatic hydrocarbons.

The general conditions of these reactions are generally as follows: average temperature of between 400 and 600 ° C., pressure of between 1 and 60 bars, hourly velocity of between 0.1 and 10 volumes of liquid naphtha per volume of catalyst and the rate of recycling between 0.5 and 20 moles of hydrogen per mole of filler.

The catalyst may contain, for example, at least one metal of the platinum family, that is to say a noble metal such as platinum, palladium, iridium, rhodium, ruthenium, osmium deposited on a suitable support (alumina, silica silica-alumina, fluorinated aluminas, fluorinated silicas, zeolite, etc ... or mixtures of such supports). The total content of noble metals is for example between 0.1 and 5% by weight relative to the catalyst. The catalyst can also generally contain at least one halogen (chlorine, fluorine, etc.) with a weight content of 0 to 15%. Optionally still, the catalyst contains at least one promoter metal chosen from the most diverse groups of the periodic table of elements, the weight content of promoter metal varying for example between 0.1 and 15%. VIII, VI A and VI
B, I bet II B, III A, IVA, VA and VB, IV B, III B, IA and IB as well as the metals of the family of lanthanides: more particularly, in addition to the noble or non-noble metals of group VIII, it will be mentioned more particularly copper, silver, gold, germanium, tin, indium, thallium, manganese, rhenium, tungsten, molybdenum, niobium and titanium.

For these catalytic reforming or aromatic hydrocarbon production reactions, the sulfurization of the new or regenerated catalyst is accompanied by a reduction of the catalyst with hydrogen and takes place at the top of the reactor or in the vicinity of the reactor head. The temperature in the sulphurization zone is dictated by the temperature at which the reduction takes place, usually between 480 and 600 ° C. In most cases, the difficulty of this type of sulphurization on the site, ie in the vicinity of the reactors, sulfurization schemes have often been tedious, although effective (USP 4 172 027).

The sulfurization agent used is in the prior art either hydrogen sulfide pure or diluted with hydrogen or by gaseous hydrocarbons, or else dimethyl di sulfide diluted with hydrogen, or other compounds sulphides such as alkyl sulphides or alkyl mercaptans, diluted with hydrogen. The pressure used is that which prevails in the reactor for reforming or producing aromatic hydrocarbons, the duration of the reaction varying from a few minutes to a few days depending on the operating conditions chosen. (see USP 4 172 027).

Sulfurization (presulphurization) of a new or regenerated catalyst is still suitable, in certain cases, for the partial or total sulphidation of catalyst, also based on one of the supports already mentioned and of at least one of the active metals already mentioned, for use in reactions, hydrocarbon conversions such as hydrogenation, dehydrogenation, alkylation, hydroalkylation, dealkylation, hydrodealkylation, water deamylation, isomerization reactions and hydrodemetallization (or demetallation) of heavy loads.

Sulfurization or presulphurization, when necessary, can be advantageously carried out according to one or the other of the techniques of the prior art mentioned above.

The metals of the catalysts used in refining, hydrorefining or petrochemicals, whether new or regenerated, are most often in oxidized form, sometimes in metallic form (for some metals reforming catalysts in particular). Since the metals of these catalysts are often active only in the sulphurated or at least partially sulphurized form, it is therefore necessary for the refiner or petrochemist to carry out a sulphidation of the catalyst prior to its use.

At present, the regeneration of catalysts is increasingly done in a catalyst regeneration specialist, sometimes far from the industrial unit. However, it seems reasonable to think of returning to the refiner a ready-to-use product, which is permitted by the efficient method of European Patent No. 84 400 234 in which a compound, which is sulphurized, is incorporated in the catalytic mass, which compound causes sulphidation or presulphurization of the catalyst when, subsequently, in the reaction zone (charge treatment zone) or in the immediate vicinity of the reaction zone, the catalyst will be brought into contact with hydrogen. of said sulfurized compound may, if desired, be carried out near the industrial unit or even at the catalyst treatment site, the method of incorporation of said sulfurized compound may be carried out offsite also on a new or regenerated catalyst , before its implementation in the industrial unit.

More precisely, in European Patent No. 84 400 234, the process for sulphurizing the catalyst is therefore characterized by a preliminary step known as incorporation into the catalytic mass of a sulfur compound of a particular nature.

The preliminary step of introduction of a sulfur compound, arbitrarily referred to as pre-treatment "off-site" or "ex-situ", whether carried out near the site of the industrial unit or remotely more or less geographically of the industrial unit (where the catalyst was regenerated or where it was manufactured, for example) is no longer in the immediate vicinity of the reactor (it is arbitrarily written "in situ"); ie at the head of the reactors or in zones more or less in direct communication with these reactors, requiring to operate under operating conditions (temperature, pressure or other), imposed at least in part by the operating conditions of the reactors themselves or annexes of these reactors (pre-hydrogenation zone of the catalyst for example).

The process makes it possible, when the catalyst is subjected from its start preferably on the site ("in situ") to an activation reaction in the presence of hydrogen (generally above 100 ° C.), to proceed, then thanks to the presence of hydrogen on the site, the sulfuration at the required rate, stoichiometric or non-stoichiometric, of the active metal or metals used in the composition of the catalyst.

In the European Patent 84,400,234, sulfur or porosity in the porosity of the new or regenerated catalyst was used to incorporate at least one sulfurizing agent of the general formula: R 1 - 5 (n) - R 2, ie a organic polysulfide.

In this polysulfide of formula: R 1 -S (n) -R 2, n is an integer from 3 to 20, and R 1 and R 2, which are identical or different, represent organic radicals each containing 1 to 150 carbon atoms per molecule, these radicals being chosen from the group consisting of alkyl radicals, that is to say saturated or unsaturated, linear or branched, or of naphthenic type, aryl radicals, alkylaryl radicals and arylalkyl radicals, these various radicals possibly comprising at least one hetero atom. R1 optionally may also be a hydrogen atom.

As a preferred example of polysulfide, mention may be made of ditertiododecylpolysulphide (n = 5) in which R 1 and R 2 are each a dodecyl radical.

Mention may also be made of ditertiononylpolysulfide (n = 5) or 1 and
R2 are each a nonyl radical (for example TPS 37 manufactured by
ELF).

In the present invention, at least one sulphurizing agent of formula: R'4-Sy ~ R ~ SX ~ R ~ Sy <R 'is incorporated in the porosity of the new or regenerated catalyst, in the absence of hydrogen. R, R ', x,
y yn y and n are defined below.

Thus, the present invention relates to a process for treating a new or regenerated catalyst containing a support based on at least one oxide of a metal or a metalloid and at least one active metal, produced in the absence of hydrogen and characterized in that said catalyst is treated with at least one specific sulfurization agent used in solution in a solvent.

The invention more specifically relates to a process for treating a new or regenerated catalyst containing a support based on at least one oxide of a metal or a metalloid and at least one active metal, with a view to carrying out subsequently, in the presence of hydrogen, the total or partial sulfurization, that is to say, in stoichiometric amounts or otherwise, of said active metal or metals used in the composition of the catalyst; the process is characterized in that the catalyst, new or regenerated, is treated "ex-situ" with the aid of at least said sulphurizing agent that is introduced between 0 and 500C in quantities required in the porosity of the catalyst.

According to the invention, the sulphurizing agent is therefore a polysulfide of general formula: R '+ -tSy-R-Sx-R-Sytn R'.These polysulfides are complex mixtures of polysulfurized olefins essentially defined by the processes to obtain them (European Patent No. 15,9936 and French Patent Application No. 27/07560.

In the general formula, R represents a hydrocarbon radical of C2 to
C12, linear or branched, depending on the olefin or olefin mixture used in the synthesis.

R 'represents an alkyl, alkenyl, arylkyl or aryalkenyl radical containing 1 to 12 carbon atoms which may contain at least one heteroatom (such as oxygen and / or nitrogen, and / or sulfur) and which depends on the monohalogenide employed in the preparation of the additive. x represents a number of consecutive sulfur atoms depending on the halide or on the sulfur halide mixture used, x taking the value from 1 to 4, preferably 1 and 2. y represents a number of a sulfur atom consecutive depending on the amount of elemental sulfur used in the synthesis being selected from 1 to 8, and preferably from 1 to 7.

Depending on the nature of R and R ', and the values of x and y, the degree of polymerization n may be such that the average molecular weight of the polymer, measured by tonometry, is about 5,000.

The main steps of the synthesis processes of these polysulfides comprise 1) the reaction of at least one compound chosen from a chloride and / or a sulfur dichloride with at least one olefin or a mixture of C 2 -C 12 olefins for to form an adduct (or "adduct") 2) the mixture of the "adduct" with at least one organic monohalide, functional or not, to form a halogenated mixture 3) the reaction of said halogenated mixture with at least one alkaline polysulfide in an aqueous and / or alcoholic medium to form a polysulfurized olefin which may contain up to 65% by weight of sulfur. Said sulphurizing agent is used in solution in a solvent. This solvent may be, for example, water or an alcohol.

According to a preferred method, the sulfurizing agent is obtained by a process in which: (1) at least one compound selected from monochloride and sulfur dichloride is reacted with at least one aliphatic monoolefin of 2 to 12 carbon atoms to form an adduct or "adduct"; (2) reacting hydrogen sulfide with sodium, potassium or ammonium hydroxide in solution in at least one substantially anhydrous aliphatic monohydric alcohol having 1 to 4 carbon atoms per molecule; (3) contacting said "adduct" formed in step (i) and at least one saturated or unsaturated monohalogenated hydrocarbon compound with the alcoholic solution obtained at the end of step (2); (4) heating the mixture resulting from step (3), removing said monoalcohol while adding water in an amount sufficient to keep reagents and minerals in solution; (5) after decantation and removal of the aqueous phase, recovering the organic phase consisting at least substantially of the desired polysulfurized olefin composition.

Preferably, in step (1), 1.5 to 2.5 moles of aliphatic monoolefin are used per mole of mono and / or sulfur dichloride and the process is carried out at a temperature of 20 to 800 ° C .;
In step (2), it is possible to use from 100 to 400 cm 3 of aliphatic monoalcohol and from 0.1 to 1 mole of hydrogen sulfide per mole of hydroxide. More particularly, from 125 to 200 cm 3 of aliphatic monoalcohol per mole of hydroxide can be used.

Advantageously, the aliphatic monoalcohol is methanol and the hydroxide is sodium hydroxide, and in step (2), elemental sulfur can be added to the reaction mixture. In this case the amount of elemental sulfur introduced is up to about 3.6 moles per mole of hydroxide introduced and preferably up to about 2.5 gram atoms per mole of hydroxide.

The composition thus obtained is such that the monohalogenated hydrocarbon compound represents from 1 to 70% in gram atoms of halogen with respect to the "adduct" + monohalogenated hydrocarbon compound, said "adduct" and said monohalogenated hydrocarbon compound being in a proportion of 1/1 to 0.5 / 1 in gram atoms of halogen per mole of hydroxide.

The operating conditions for obtaining the composition (sulphurizing agent) can advantageously be as follows: the reaction of step (3) is carried out under a relative pressure of up to about 1 MPa. In step (4), the temperature is from 50 ° C to the reflux temperature of the medium.

It is possible to carry out a sixth step in which the polysulfurized olefin composition obtained is brought into contact with a basic compound and then washed with water; the process for the preparation of the composition can be carried out continuously in a parallel flow and multi-contact process.

This composition, which has a sulfur content of up to 65% by weight, may have a chlorine content of less than about 0.1% by weight, or less than about 0.05% by weight.

According to another preferred method, the sulphurizing agent can be obtained by carrying out the following steps: (1) at least one compound chosen from monochloride and sulfur chloride is reacted with at least one monoolefin of 2 to 12 carbon atoms in a proportion of 1.5 to 2.5 moles of monoolefin per mole of monochloride and / or sulfur dichloride, thereby forming an adduct or adduct; (2) said adduct is brought into contact with at least one hydrocarbyl halide selected from C1 to C12 alkyl chlorides, bromides and iodides, C5 to C12 substituted cycloalkyl or cycloalkyl radicals and arylalkyl or substituted C6 to C12 arylkyl group, the proportion of said alkyl halide corresponding to 1 to 70% to gram atoms of halogen relative to the number of gram atoms of halogen of the combination formed by said adduct and said hydrocarbyl halide, with at least one sulfur compound selected from sulphides, hydrogen sulphides and polysulfides of alkali metals, ammonium or alkaline earth metals, involved in one. a proportion of about 0.4 to 0.8 moles per gram atom of halogen contained in the combination of said adduct and said hydrocarbyl halide, and a proportion of elemental sulfur of 0 to 7 gram atoms per mole said sulfurized compound, in a medium consisting of water or a mixture of water and aliphatic monoalcohol; and (3) The resulting mixture is heated and after separation into two phases, the polysulfurized olefin is recovered from the organic phase.

In step (1), isobutene or a mixture of isobutene with a minor proportion of diisobutene may be used as the aliphatic monoolefin.

Said hydrocarbyl halide may be selected from chlorides, bromides and iodides of methyl, ethyl, isopropyl, n-propyl, tert-butyl, isobutyl, n-butyl, tert-amyl, isoamyl, n-amyl, n-hexyl, 2-ethylhexyl, n-octyl, cyclohexyl and benzyl.

It will be noted that this hydrocarbyl halide may consist at least in part of a monohalogenated hydrocarbon compound bearing at least one functional group chosen from alcohol, phenol, carboxylic acid, amine, amide and thiol functional groups.

In addition, said sulfurized compound may be chosen from sodium sulphide, sodium hydrogen sulphide and sodium polysulfides.

In the last method indicated above, the proportion of elemental sulfur can range from 0.4 / 1 to 7/1 gram atoms per mole of sulfurized compound, whereas in step (2), the said adduct and the said halide of hydrocarbyl are added to the medium containing said sulfurized compound and optionally the elemental sulfur and maintained at a temperature of 20 to 100 ° C, in the space of 10 minutes to 3 hours, in step (3), it is possible to heat at a temperature ranging from 50 ° C to reflux for 3 to 10 hours.

It is possible to envisage a fourth step (4) in which the product resulting from step (3) is treated with a basic compound. As for the first preferred method, described above, it is possible from step (2) to carry out the operations continuously, the reagents involved in the step (2) being brought into contact in parallel currents and according to a multi-contact process. All other operating conditions and particular compositions are given in
EP-B No. 159,936.

According to a preferred method of the invention, it is possible to carry out the sulphurization of the catalyst in two stages A and B.

A / In a first step carried out "ex-situ", in the absence of hydrogen, generally between 0 and 50 ° C, the catalyst is treated with at least one sulphurizing agent so as to incorporate partially or totally this agent in the porosity of the catalyst;
B / In a second step preferably carried out "in situ" and above 100 ° C., and preferably above 140 ° C., a catalyst activation step is generally carried out in the presence of hydrogen, (optionally also in the presence of 0.1 to 10% by volume of vapor, for example between 0.1 and 1%), on the metal or metals used in the composition of said catalyst.This second stage is generally carried out by the refiner. some details are shown below.

The drawbacks of a conventional "in situ" sulphurisation method can be summarized as follows: - too high working temperature - malodorous and toxic product (H2S, CS2, DMS or DMDS) use; - risk of passivation of the metal by reduction of the oxides before their sulfurization - impossibility of using charges containing olefins to avoid any risk of polymerization - difficulty of using heavy charges of the vacuum distillate type or residues because of their very low wetting ability due to their high viscosity; - duration of the sulphurisation (from several hours to several days).

The advantages of the preliminary treatment of incorporation according to the invention of a sulphurized compound, ex-situ, are the following: - low working temperature; - the choice of complete and homogeneous sulphurization of the catalyst or sulphurization at the exact rate of sulphurization demand; no risk of causing a reduction of the oxidized metals because, according to the invention, the treatment is carried out in the absence of hydrogen; easy handling of catalysts rendered non-pyrophoric by the addition of water and light gasoline; - practically no bad smell and no toxicity - possibility of using the catalyst for all dense loading methods - saving time for the refiner and for the user of the catalysts - maximum activity obtained from feeding the reactor with the feed to be desulphurized .

The research carried out in the context of the invention has led to the development of an "ex-situ" sulphurization method for new or regenerated catalysts, a method that has the advantage of significantly limiting the industrial infrastructures required by presulphuration techniques. of the prior art.

The object of this invention is therefore to conduct "ex-situ" the presulphurization of the catalysts by incorporating all the necessary amount of sulfur and only the required amount of sulfur required by the user. The catalysts are therefore delivered to the refinery or any other unit, thus preconditioned to be presulfided.

The refiner, or any other user, will therefore only have to reactivate this catalyst in the presence of hydrogen at a temperature of, for example, 100 to 200 ° C. for a desulphurization catalyst, from 400 ° to 600 ° C., for a catalyst. catalytic reforming or aromatic hydrocarbon production, in order to react the sulfur on the contained metals and immediately start the reaction of refining or hydrocarbon conversion by injection of the charge to be treated.

The process for the sulphidation or presulfidation of catalyst according to the invention is therefore characterized by a pretreatment of the catalyst with the aid of a sulphurizing agent as defined above.

The process according to the invention for incorporating sulfur into the catalyst is carried out in the absence of hydrogen and makes it possible to obtain with a very high degree of degree of total or partial sulphurization requested by the user. This sulfur incorporation is carried out between 0 and 50 ° C and preferably between 10 and 35 ° C and more preferably at room temperature.

The sulfurization according to the invention thus makes it possible to fix on the catalyst, with great accuracy, by dilution with a chosen solvent, the appropriate amount of sulfur, a stoichiometric amount for example for hydrodesulfurization catalysts and non-stoichiometric quantities but critical for the catalysts for reforming or producing aromatic hydrocarbons, these critical quantities depending on the nature of the metal or each of the metals used in the composition of the catalyst. (It is known that sulfur is a poison reforming catalysts and therefore it is necessary to perfectly control the exact incorporation of sulfur desired, which allows precisely the method of the invention). The present process thus makes it possible to carry out the sulphurization rate in accordance with the wishes of the user of the catalyst. The sulphurization agent is used, diluted in a suitable solvent which depends in particular on the nature of the sulphurising agent. that is, the values of x, y and n, and the nature of the radicals R and R ', these characteristics determining the sulfur content incorporated in the catalyst generally by capillarity or by porosity. The sulphurization processes vary in fact according to the sections to be treated later in the presence of the catalysts treated in accordance with the invention. The solvent chosen can thus be one of the following solvents used alone or mixed together - a light gasoline boiling for example between about 60.degree. and 95 ° C; a boiling hexane type gasoline at about 63 ° C to about 680 °; a type F gasoline boiling at about 100 to 160 ° C and generally containing 10 to 20% aromatic hydrocarbons, for example 15%, (by volume) - A gasoline type "white spirit" boiling between about 150 and 250 "C and generally containing 14 to 22% of aromatic hydrocarbons, for example 17%, by volume - or any hydrocarbon or non-hydrocarbon fraction, equivalent to the preceding species.

Thus, in accordance with the invention, a particular sulfur-containing compound which will be blocked from its introduction into the catalytic mass is used as sulphurization agent. Subsequently, in-situ, that is to say on the site or near the site (on which the catalyst will be used for the treatment of various charges), during the conventional activation reaction, carried out in the presence of hydrogen, the sulphurizing agent introduced into the catalyst in predetermined quantities, will be capable of giving rise to hydrogen sulphide which, in the presence of hydrogen, will lead to the desired sulphide or sulphides of the metal or metals present in the catalyst according to for example, the following exothermic reactions (1) (2) and (3) with regard to, for example, the sulphurizations of molybdenum, cobalt and nickel

The use of a suitable solvent, in which the sulphurizing agent is dissolved, makes it possible to play on the latent heat of vaporization of the chosen solvent, thus to absorb at least part of the exothermicity of the sulphurization reaction.

Another advantage of the "ex-situ" process according to the invention is that it is not necessary to use hydrogen immediately, hence the uselessness here of handling this gas. Hydrogen, of course, is necessary then to proceed with the activation of the catalyst but this activation is carried out on the site itself since anyway, on the site, the use of hydrogen is generally necessary for the treatment of the sections to be treated in the presence of the presulfided catalyst according to the invention.

The following tests, given as non-limiting illustrations, give a better understanding of the interest of the invention.

It will be added that, in general, the presulphurization of the catalysts may be carried out on a new or regenerated product, that this presulphurization is therefore carried out by adsorption of a stoichiometric amount, relative to the metals, of polysulfides with a high sulfur content, that the adsorption of this polysulfide will be facilitated by dilution in a solvent, especially in white spirit. The volume of polysulfide and the chosen solvent should preferably be about a value equal to the pore volume of the catalyst bed to be treated: Thus, for example, per 100 g of regenerated catalyst or new (oxidized form) is therefore to put about 9 grams of polysulfide sulfur in about 45 cm of total polysulfide mixture plus solvent (white spirit for example). The adsorption of this polysulfide is generally done in ambient air.

The solvent is then preferably removed in an inert or non-oxidizing atmosphere, for example by steam distillation.

The drying operation is advantageously at a temperature of between 50 and 2000C.

The activation operation is then performed by the refiner in the reactor where is placed the catalytic charge and presulfurized.

The bed can be purged with hot nitrogen to eliminate any presence of oxygen gas during storage or transport of the catalyst.

In the reactor of the refinery, just before sending the charge to be treated to start the activation, it is then possible to pass a hydrogen flow, for example at 1500 ° C., with a hourly flow corresponding, for example, to at least 40 times the volume of the catalytic bed.

The temperature will slightly increase because of the exotherm; the gaseous mixture that is created (the H2 + H2 S mixture produced) may optionally be recycled and may be used to limit the rise in temperature. The temperature should preferably be greater than 100 ° C. to avoid any condensation of a liquid and less than 200 ° C. to avoid any risk of overheating.

The monitoring of the sulphurization is done by the control of the temperatures, the evolution of the content of H2S, the quantity of water collected in the purge gas after condensation (with the separation tank).

The main advantages of the process are described below: sulfurization work being carried out at a lower temperature; - easy handling of catalysts because we do not deal with very smelly sulphides; polysulfide olefins having a moderate odor and having no toxic character; more homogeneous sulphurization of the catalytic bed; - possibility of using the infrastructures of ex-situ catalysts regeneration plants; - reduced industrial infrastructure; - more storage of sulfide product difficult to use as the DMDS; - downtime of reactors reduced; no risk of reduction of the metals which causes the hydrocracking reactions and not the desired hydrodesulphurization reactions which are generally sought selectively; in the case of hydrorefining of heavy cuts with a view to their hydrocracking or demetallization, the refiner is often forced to presulfurize the catalyst using a light load which must then be stored. In the context of this invention, it will no longer be necessary to proceed in such a complicated way, since the catalyst will already be sulfurized at the time of sending the charge to be treated.

It has also been found, in the context of the present invention, a means for subsequently accelerating the reactivation of the catalyst with hydrogen by converting the oxides of the active metals to metal sulphide.

This means consists in operating the "ex-situ" incorporation of the poly-sulfide into the porosity of the catalyst, in the presence of at least one additive having reducing properties and which is selected from the group consisting of aldehydes containing 4 to 14 carbon atoms per molecule (and preferably 5 to 12 carbon atoms), ketones or polyketones containing 3 to 18 (and preferably 5 to 12) carbon atoms per molecule, the ethers containing 5 to 14 (preferably 6 to at 12) carbon atoms per molecule, the alcohols or polyalcohols containing 5 to 14 (and preferably 6 to 12) carbon atoms per molecule and the organic acids or polyacids containing 3 to 14 (and preferably 6 to 12 carbon atoms per molecule).

0.4 to 8% by weight, preferably 0.8 to 4% and more particularly 0.9 to 3% by weight of the additive or additives selected with respect to the weight of the polysulfide or polysulfides used, will advantageously be used.

The additive (s) may be added, for example, with the solution of the polysulfide (s) used, either in the pure state or dissolved in a suitable solvent. This solvent may be of the same type as the solvents chosen for dissolving the polysulfide, namely, for example - a light gasoline boiling for example between about 60 and 950 ° C - a hexane type gasoline boiling between about 63 and 68 ° C. type F gasoline boiling between about 100 and 1600C and generally containing 10 to 20% aromatic hydrocarbons, for example 15% (by volume); -a "white spirit" type gasoline boiling between about 150 and 250 ° C and containing generally 14 to 22% aromatic hydrocarbons, for example 17%, by volume; - any hydrocarbon cut or not, equivalent to the previous species.

The additive or the additives according to the invention can be used in another solvent such as, for example, alcohols (methanol, ethanol, propanol, etc.) or other mineral or organic liquids known to dissolve aldehydes, ketones, ethers, alcohols, polyalcohols, acids and polyacids which can be used according to the present invention.

Examples of these additives are found in European Patent No. 84,400,234.

In Examples 1 to 4 which follow, we will study, for a hydrorefining or hydrotreating of a hydrocarbon fraction, the impact of the catalyst sulfidation method adopted.

The cut proposed for hydrorefining is a model load containing by weight
20% toluene
2% thiophene
78% cyclohexane
The operating conditions are as follows
Temperature: 360 "C
Total pressure: 60 bar
VVH: 2
H2 / HC: 350 l / h
Duration of treatment: 48 hours
Catalyst volume involved: 40 cc in the 4 examples 1 to 4 in order to determine the best performing route.

# p représentant la somme des titres molaires des produits de conversion du toluène (méthylcyclohexane, éthylcyclopentane et les diméthylcyclopentanes) et # T représentant la somme Zp + titre de toluène résiduel.The analysis of the effluents is carried out by gas chromatography. The hydrogenation ("A") activity of toluene and the isomerization ("I") activity of cyclohexane to methylcyclopentane will be measured in each test;
1
A = Log lX (natural logarithm) where X is the conversion rate of toluene, that is to say

# p representing the sum of the molar titers of the toluene conversion products (methylcyclohexane, ethylcyclopentane and dimethylcyclopentanes) and # T representing the sum Zp + residual toluene titer.

X is between 0 and 1, X being 1 for 100 X conversion of toluene.

I = 100 x molar title of methylcylpentane
Methylcyclopentane molar title
+ residual molar ratio of cyclohexane (the activity in isomerization I makes it possible to measure the acidity of the catalyst).

The catalyst used is a commercial catalyst of the company
Procatalyse containing by weight 4% nickel oxide NiO and 16% MoO3 molybdenum oxide, these active metal compounds being deposited on a gamma-alumina.

EXAMPLE 1 (Comparative)
Before starting the hydrorefining, the catalyst is presulfided according to a conventional method, operating as follows
The catalyst, whose active metals are in the form of their NiO and MoO 3 oxides, is charged to the reactor.

The unit is purged under hydrogen, under cold conditions, and under a pressure of 1 bar (it has been verified that the results would be the same if this step were carried out under a high pressure, 60 bars for example).

The catalyst is heated to 1500C under hydrogen at 1 bar (or 60 bar).

The reactor inlet, whose temperature is 150 ° C. (at 60 bars of pressure), is injected with a sulphurization charge containing by weight
20% toluene
2% diethyl sulphide
78% cyclohexane
Dimethyldisulphide causes sulfurization of nickel and molybdenum oxides. The operating conditions for sulphurisation are as follows
VVH: 2
H2 / HC-: 350 l / h
The temperature is increased to 280 ° C. and the sulphurization is continued for 2 hours, then the temperature is raised to 320 ° C. for two hours and finally the temperature is brought to 35 ° C. for a further two hours. The sulphurization of the catalyst being carried out, then substitutes for the sulfurization charge, the charge to be hydrorefined and the hydrorefining of this charge under the operating conditions given above.

Results
A = 1.2
I = 0.6
EXAMPLE 2 (comparative), carried out according to the technique of EP 84 400 234.

In this example, the catalyst is sulphurized according to the method of European Patent No. 84 400 234, in two stages.
First stage
For the presulphurization of the catalyst, TPS 37, manufactured by ELF Aquitaine and containing about 37% by weight of sulfur, (the formula was given in the general part of this patent application); in order for all of the polysulfide to be adsorbed, a volume of reagent (polysulfide + polysulfide solvent) equal to the impregnation volume of the treated catalyst feed must be used. It is the knowledge of this total pore volume, or impregnation volume, which determines the amount of solvent to be used. In the context of the present test, this volume, per 100 g of catalyst, is 45 ml on average (of which 60% of solvent and 40% of polysulphide). The solvent used is a white spirit (boiling point between 150 and 250 C). We operated at 24 ° C.

Stoichiometry is used. in sulfur necessary to subsequently sulphurize all the oxides (NiO, MoO3) or 8.5% S. This is followed by the dry impregnation of the catalyst, followed by evaporation under 10 mm of mercury or under a stream of inert gas .

Second step
The catalyst whose metals are in the form of oxides and containing sulfur in its porosity, is introduced into the reactor. The reactor is purged of air and placed in a cold hydrogen atmosphere, under 1 bar (the subsequent results are not changed if the pressure adopted was higher, 60 bar for example). The catalyst impregnated with polysulfide is heated under hydrogen at 150 ° C. in the presence of superheated steam (1% by volume) and the temperature is maintained at 1500 ° C. for 2 hours. The catalyst becomes black, this being due to the formation of metal sulfides. Analysis of the TPS sulphurized catalyst 37 gives a sulfur value of 8.0% S (weight) and a carbon value of 3% (weight).

Hydrorefining test
The pressure in the reactor is raised to 60 bar and the temperature is raised continuously to 350 C.

Results
A = 1.35 I 0.8
Example 3 (according to the invention)
The procedure is as in Example 2 in two stages, but here used for the presulphurization of the catalyst an agent obtained in the following manner
In a 1-liter reactor equipped with a stirrer, 270 g of sulfur monochloride S2C12 (2 moles) are introduced, then, via a dip tube, is introduced under the surface of the S2C12 constantly stirred, 253 isobutylene. (4.87 moles), in which 2.5 g of methanol had previously been dissolved. The temperature of the reaction medium is maintained between 45 and 50 ° C throughout the duration of introduction of isobutylene (1 hour).

There is thus obtained 500 g of adduct which is designated by the term "adduct".

In a second reactor of 1 liter equipped with an agitator and surmounted by a system allowing the distillation, 98 g of sodium hydroxide in pellets (2.45 moles) and 400 cm3 of anhydrous methanol are introduced, then the mixture is agitated until at complete dissolution.

41.65 g of hydrogen sulfide (1.225 mol) are introduced over a period of 1 hour through a tube immersed in the alcoholic phase, the reaction mixture being maintained at 50 ° C. by external cooling.

152 g of flowering sulfur (4.75 g) are then added to the medium, and the mixture is then heated with stirring at the reflux temperature of methanol for 1 hour to promote the formation of sodium polysulfide.

By means of a dropping funnel, a mixture consisting of 110 g of "adduct" and 105 g (ie approximately 113.4 × 10 2 mol) of sodium chloride is introduced into the alcoholic solution of sodium polysulfide. butyl (duration of introduction: 4 hours), the reaction temperature being regulated by the reflux of methanol to boiling.

It is allowed to react at reflux for 7 hours, then the methanol is gradually removed by distillation, while, at the same time, 350 cm3 of water are gradually introduced into the boiling mixture.

After complete distillation of the methanol, the hot organic phase is separated from the aqueous phase containing the formed NaCl and the excess of sodium polysulfide.

After decantation, the recovered organic phase is washed twice with 200 cm3 of water, dried over anhydrous Na 2 SO 4 and filtered. Thus, 218.7% of an orange yellow liquid whose characteristics are - sulfur contained in the additive (% mass) are collected: 63.8 - residual chlorine in the additive (% by mass): 0.0125 (125 ppm )
(X-ray fluorescence assay) - kinematic viscosity at 100 ° C (mm2 / s): 12.3
At the end of the first step, according to the process according to the invention, carried out under the operating conditions of Example 2, the catalyst impregnated with the sulfur compound is subjected to the second step in accordance with the second step of Example 2 After the treatment for 2 hours at 1500C, the catalyst is cooled under nitrogen to room temperature.

The analysis of the catalyst gives 8.5% by weight of sulfur and about 2% by weight of carbon.

The hydrorefining test is carried out in the same manner as in Examples 1 and 2 and the following results are obtained:
A = 1.45
I = 1.0
EXAMPLE 4
A catalyst is presulfided by proceeding as in Example 3. The catalyst is still the one used in the preceding examples. It is carried out in a CATATEST reactor, and an HDS and hydrodenitrogenation test is carried out on a coking gas oil: once the catalyst has been charged, the reactor is purged with air and then swept H2 cold, the pressure is raised to 100 bar.

We heat up. The gas oil feed is injected when the catalyst has reached 150 ° C. It is raised to 300 ° C. and 15 mm remain at this temperature, then the reaction temperature is maintained (300 ° C.) and the reaction temperature is maintained. very representative test of industrial conditions of use of the catalyst.

The test conditions shown in Table 2. The characteristics of the coking gas oil feed in Table 1.

The performances in HDS and HDN stabilized after 60 hours and then 120 hours of continuous operation are compared with the performances obtained under the same conditions, on the same catalyst, but in situ sulphurized as described in Examples 1 and 2.

<Tb>

<SEP> R100 <SEP> b <SEP> 60 <SEP> b <SEP>
<tb><SEP> VVH <SEP> = <SEP> 4 <SEP> VVH <SEP> = <SEP> 2
<tb><SEP> after <SEP> 60 <SEP> hours <SEP> after <SEP> 120 <SEP> hours
<tb><SEP> HDS <SEP> | <SEP> HDN <SEP> HDS <SEP> HDN
<tb> Technical <SEP> of <SEP> Ex. <SEP> 1 <SEP> 96.8 <SEP> 84.9 <SEP> 97.2 <SEP> 81.2
<tb> Technical <SEP> of <SEP> the Ex. <SEP> 2 <SEP> 95.8 <SEP> 85.9 <SEP> 97.5 <SEP> 82.9
<tb> Desulfurized <SEP> Catalyst <SEP> 96.6 <SEP> 86.6 <SEP> 97.7 <SEP> 85.0
<tb><SEP> according to <SEP> the invention
<Tb>
The ex-situ presulphurization technique according to the invention gives a substantially better result than the other techniques.

<tb><SEP> TEST <SEP> GO <SEP> COKING
<tb><SEP> Tier <SEP> I
<tb><SEP> Total <SEP> pressure <SEP> (bars) <SEP> 100
<tb><SEP> Temperature <SEP> (OC) <SEP> 360
<tb><SEP> VVH <SEP> 4
<tb><SEP> Report <SEP> H2 / HC <SEP> (N1 / 1) <SEP> 250
<tb><SEP> Time <SEP> (hours) <SEP> 60
<tb> Step <SEP> 2
<tb><SEP> Total <SEP> pressure <SEP> (bars) <SEP> 60
<tb><SEP> Temperature <SEP> (oC) <SEP> 360
<tb><SEP> VVH <SEP> 2
<tb><SEP> Report <SEP> H2 / HC <SEP> 250
<tb><SEP> Lifetime <SEP> (hours) <SEP> 60
<tb> Volume <SEP> of <SEP> catalyst <SEP> (cm3) <SEP> 50
<tb> Presulfuration <SEP> with <SEP> charge <SEP> toluene <SEP> + <SEP> CC6 <SEP> + <SEP> DMDS
<Tb>

Table 2
Characteristics of the catalytic test.

<Tb>

CHARGE <SEP> GO <SEP> of <SEP> COKING
<tb> Density <SEP> to <SEP> 20 <SEP> oC <SEP> (g / cm3) <SEP> 0.857
<tb> Sulfur <SEP> (% <SEP> wt) <SEP> 0.45
<tb> Nitrogen <SEP> (ppm <SEP> wt) <SEP> 420
<tb> Weight <SEP> Molecular <SEP> Medium <SEP> (g) <SEP> 205
<tb> Index <SEP> of <SEP> Bromine <SEP> (959) <SEP> 17
<tb> Point <SEP> of <SEP> disorder <SEP> - (oC) <SEP> -9
<tb><SEP><SEP> cetane <SEP> Index <40
<tb> Distillation <SEP> NF
<tb><SEP> M07-002
<tb><SEP> PI <SEP> (oC) <SEP> 161
<tb><SEP> 5% <SEP>"<SEP> 194
<tb><SEP> 10S <SEP>"<SEP> 203
<tb><SEP> 505 <SEP>"<SEP> 256 <SEP>
<tb><SEP> 90t <SEP>"<SEP> 328
<tb><SEP> 95% <SEP>"<SEP> 338
<tb><SEP> PF <SEP>"<SEP> 350
<Tb>
Table 1
Characteristics of the test load.

Examples 3 and 4 show that the process according to the invention provides the advantages mentioned above, a significant gain in terms of catalytic performance compared to the activation techniques of the refining catalysts according to the prior art.

Claims (9)

1. - Process for the treatment of a new or regenerated catalyst containing a support based on at least one oxide of a metal or a metalloid and at least one active metal, produced in the absence of hydrogen and characterized in that said catalyst is treated with at least one sulfurizing agent used in solution in a solvent, said agent being a polysulfide of general formula  R '± Sy-R-Sx-RSy ~ tn R'  wherein R is a linear or branched organic radical having 2 to 12 carbon atoms, R 'is an alkyl, alkenyl, arylalkyl or aryl kenyl radical having 1 to 12 carbon atoms, R' optionally containing at least one heteroatom selected from group consisting of oxygen, nitrogen and sulfur, x has the value 1 to 4, y is 1 to 8. 2. - Process according to claim 1 for treating a new or regenerated catalyst, comprising a support based on at least one oxide of a metal or a metalloid and at least one active metal, in order to subsequently, in the presence of hydrogen, the total or partial sulfurization, that is to say, in stoichiometric amounts or otherwise, of said active metal or metals in the composition of the catalyst, the process being characterized in that the The catalyst, new or regenerated, is treated "ex-situ" using at least said sulfurizing agent which is introduced between 0 and 50 ° C in the amounts required in the porosity of the catalyst. 3. - Process according to one of claims 1 and 2 for partial or total sulphidation of an active metal or at least one of the active metals used in the composition of a catalyst containing (a) a carrier based on at least one oxide of a metal or metalloid and (b) at least one so-called active metal, the sulphurization process being characterized in that in a first step carried out "ex-situ" and in the absence of hydrogen, the catalyst is treated with at least one sulphurizing agent so as to partially or totally incorporate this agent in the porosity of the catalyst, the sulphurizing agent being in solution in a solvent, and in that in a second stage, carried out "in situ", which is the stage of activation of the catalyst carried out in the presence of hydrogen, the catalyst obtained in the first stage is treated with hydrogen to fix the required amount of sulfur on the or the metals used in the composition of said catalyst. 4. - Method according to one of claims 1 to 3, wherein the sulfurizing agent contains between 20 and 70% by weight of sulfur. 5. - Method according to one of claims 1 to 4, wherein said solvent in which is dissolved the sulfurizing agent is selected in at least one of the group consisting of a light gasoline boiling between about 60 and 95 "C , a hexane type gasoline boiling between about 63 and 68 ° C, a type F gasoline boiling between about 100 and 1600C (and containing 10 to 20% by volume, aromatic hydrocarbons) and a gasoline type "white spirit" "boiling between about 150 and 250 ° C (and containing about 14 to 22%, by volume, aromatic hydrocarbons). 6. - Method according to one of claims 1 to 5, characterized in that one operates in the presence of 0.4 to 8% by weight relative to the weight of polysulfide of at least one additive selected from the group consisting of by aldehydes containing 4 to 14 carbon atoms per molecule, ketones or polyketones containing 3 to 18 carbon atoms per molecule, ethers containing 5 to 14 carbon atoms per molecule, alcohols or polyalcohols containing 5 to 14 carbon atoms, carbon per molecule and organic acids or polyacids containing 3 to 14 carbon atoms per molecule. 7. - Method according to one of claims 1 to 6 wherein the sulfurizing agent is obtained after a synthesis process which comprises a) reacting at least one compound selected from a sulfur chloride with minus one olefin or a mixture of olefins having 2 to 12 carbon atoms per molecule, to form an adduct, or ("adduct"), b) to mix, said adduct with at least an organic monohalide functional or not to form a halogenated mixture; c) reacting said halogenated mixture with at least one alkaline polysulfide in an aqueous and / or alcoholic medium to form a polysulfide olefin capable of containing up to 65% by weight of sulfur. 8. - Process according to one of claims 1 to 7 wherein the sulfurizing agent is based on a polysulfurized olefin composition with a high content of sulfur and very low chlorine content, obtained by a process in which (1) reacting at least one compound selected from monochloride and sulfur chloride with at least one aliphatic monoolefin of 2 to 12 carbon atoms to form an adduct; (2) hydrogen sulfide is reacted with sodium, potassium or ammonium hydroxide in solution in at least one substantially anhydrous aliphatic monoalcohol having 1 to 4 carbon atoms per molecule; (3) contacting said "adduct" formed in step (1) and at least one saturated or unsaturated monohalogenated hydrocarbon compound with the alcoholic solution obtained at the end of step (2); (4) the mixture resulting from step (3) is heated, said monoalcohol is removed while adding water in a sufficient quantity to keep reagents and mineral products in solution; (5) after decantation and removal of the aqueous phase, recovering the organic phase consisting at least in major part of the desired polysulfurized olefin composition. 9. - Process according to one of claims 1 to 7 wherein the sulfiding agent is based on a polysulfurized olefine, the preparation comprises the following steps: (1) reacting at least one compound selected from monochloride and sulfur dichloride with at least one monoolefin of 2 to 12 carbon atoms in a proportion of 1.5 to 2.5 moles of monoolefin per mole of monochloride and / or sulfur dichloride, thereby forming a product of (2) The "adduct" is brought into contact with at least one hydrocarbyl halide selected from C1 to C12 alkyl, cycloalkyl or cycloalkyl chlorides, bromides and iodides. substituted C5 to C12 and substituted arylalkyl or arylalkyl of C6 to C12, the proportion of said alkyl halide corresponding to 1-70% to gram atoms of halogen relative to the number of gram atoms of halogen of the group formed by said "adduct" and said hydrocarbyl halide, with a at least one sulphurized compound chosen from sulphides, hydrogen sulphides and polysulfides of alkali metals, of ammonium or of alkaline earth metals, used in a proportion of approximately 0.4 to 0.8 mol per gram atom; halogen content contained in the assembly formed by said "adduct" and said hydrocarbyl halide, and a proportion of elemental sulfur of 0 to 7 gram atoms per mole of said sulfur compound, in a medium consisting of water or a mixture of water and aliphatic monoalcohol; and (3) The resulting mixture is heated and, after separation into two phases, the polysulfide olefin is recovered in the organic phase.