KR100456686B1 - Incorporation of sulfur into the pores of a hydrocarbon treatment catalyst - Google Patents

Abstract

The present invention is directed to a process comprising one or two steps for the incorporation of sulfur into the pores of a hydrocarbon conversion catalyst.

The process according to the invention is carried out in the presence of hydrogen sulfide non-identically in one or more zones containing a catalyst, preferably a running catalyst, or in the presence of sulfur or sulfur compounds, ie sulfur compounds which can yield initial hydrogen sulfide. .

The present invention relates to a prevulcanization process for hydrocarbon treating catalysts and / or a preconditioning method for catalysts.

Description

Incorporation of sulfur into the pores of a hydrocarbon treating catalyst

The present invention is directed to a process comprising one or two steps for incorporating sulfur into the pores of a hydrocarbon conversion catalyst.

The process according to the invention is carried out in the presence of hydrogen sulfide non-identically in one or more zones containing a catalyst, preferably a running catalyst, or in the presence of sulfur or sulfur compounds, ie sulfur compounds which can yield initial hydrogen sulfide. .

The present invention relates to a prevulcanization process for hydrocarbon treating catalysts and / or a preconditioning method for catalysts.

Metals comprised as a component of certain purification catalysts and / or hydrocarbon hydroconversion catalysts are vulcanized (generally "prevulcanized") when these catalysts are first used or later in the regeneration phase prior to reuse. Is often preferred.

Thus, new catalysts or regenerated catalysts may be employed for use in purifying reactions, such as hydrotreating or hydrodesulfurization or hydrocracking of various petroleum fractions that require reducing sulfur content or improving other properties prior to use. Prevulcanization is preferred.

The reactions described above (particularly hydrotreating reactions) are generally in the presence of hydrogen at temperatures of 200 to 400 ° C., pressures of 5 to 200 bar, volume flow rates of 0.1 to 10 (expressed as liquid batches m 3 injected per m 3 of catalyst per hour). Is performed.

Catalysts used for this type of hydrotreatment can be selected from a substrate, for example alumina or an alumina mixture (US Pat. No. 4,334, 982), or any other suitable substrate based on oxides of one or more metals or semimetals, e.g. For example magnesia, silica, silica-alumina, silica-magnesia, boron alumina clay, carbon, fluorinated alumina, wherein the base mixture (s) may be present at least partially in amorphous or crystalline (zeolite). The catalyst also contains from 0.2 to 30% of one or more active metals, such as Groups VI, VIII, selected from the group consisting of cobalt, molybdenum, nickel and tungsten, for example (US Pat. Nos. 3,732,155 and 3,804,748). number). In general, one of a pair of two metals, for example, cobalt-molybdenum and nickel-molybdenum nickel-tungsten pair, is used. For example, platinum-based precious metals Pt and Pd of the group VIII can always be used (US Pat. No. 4,098,682).

Therefore, in the prior art, vulcanization (pre-vulcanization) treatment is generally performed before using a new catalyst or a regenerated catalyst, which treatment is carried out in a hydrodesulfurization reactor. Is by a vulcanization reaction catalyst, for example, sulfur-containing molecular formula (according to the present metal), that is, when calculated based on the amount of _{Co 9 S 8, MoS 2,} WS 2 and Ni ₃ S ₂ from about 50 to 110% of the theoretical amount of sulfur can be contained.

The vulcanization reaction (preliminary vulcanization) is generally hydrogen for several hours at a temperature similar to or higher than the reaction temperature selected for prior art dehydrosulfurization reactions (ie at least 180 ° C., more preferably at least 250 ° C.). It is carried out using a mixture of hydrogen sulfide diluted in water (the ratio of hydrogen sulfide to hydrogen is 0.5 to 5% by volume) (US Pat. No. 4,334,982). The vulcanization reaction (or prevulcanization reaction) itself can be carried out at a temperature plateau (European Patent EP-B-64429). Various vulcanizing agents other than hydrogen sulfide (H ₂ S), such as mercaptan-based sulfide compounds, carbon sulfides (CS ₂ ), sulfides or disulfides, thiophene compounds, and preferably dimethyl sulfide (DMS) and dimethyl disulfide (DMSO) or polysulfide may be used.

In the case of hydroreforming reactions of hydrocarbons, for example, the catalyst may contain one or more of the platinum-based metals, ie precious metals such as platinum, palladium, iridium, rhodium, ruthenium, or osmium. It is deposited on a suitable substrate (alumina, silica, silica-alumina, fluorinated alumina, fluorinated silica, zeolites or the like or a mixture of such substrates). The total content of the noble metal is, for example, 0.1 to 5% by weight relative to the catalyst. The catalyst may also contain one or more halogens (chlorine, fluorine, etc.) in a content of generally 0 to 15% by weight. If appropriate, the catalyst also contains one or more promoting metals selected from the broad group of the periodic table.

In the case of the reactions used for catalytic reforming or aromatic hydrocarbon production, the vulcanization of new or regenerated catalysts involves the hydrogen reduction of the catalyst, which takes place at or near the top of the reactor. The temperature of the vulcanization reaction zone is in most cases the temperature at which the reduction reaction takes place, ie generally 480 to 600 ° C. This type of in-situ vulcanization, ie vulcanization near the reactor, is effective but often requires the need for tedious vulcanization (US Pat. No. 4,172,027).

The vulcanizing agents used in the prior art are either pure or diluted with hydrogen (under the operating conditions given above) or hydrogen sulfide diluted with gaseous hydrocarbons, or dimethyl disulfide diluted with hydrogen, or alkyl sulfide or alkyl diluted with hydrogen. Other sulfide compounds such as mercaptans.

In some cases the vulcanization reaction (preliminary vulcanization) of a new catalyst or a regenerated catalyst is also suitable for partial or total catalytic vulcanization reactions, based primarily on one or more of the above-described substrates and one or more of the aforementioned active metals, which is a hydrogenation reaction. , Dehydrogenation, alkylation, hydrogenoalkylation, dealkylation, dehydroalkylation, dealkylation with water vapor, isomerization and heavier demetallization (or demetallization) It can also be used for hydrocarbon conversion reaction such as).

If necessary, it may be advantageous to carry out a vulcanization reaction or a prevulcanization reaction according to one of the prior art described above.

Another purification reaction that may be particularly suitable for this type of prevulcanization reaction is hydrocracking. Hydrolysis of the heavy fuel fraction (the term cracking is appropriate in this case) is a very important purification process, from light gasoline, light jet fuel, and light gas from excess heavy batches that cannot be easily improved. Because it allows the production of lighter fractions, such as gas oils, it is a process used by refiners in cases where the manufacturing process is to be adapted to the demand structure. Batches used for hydrogenolysis are gas oils, gas oils under vacuum, deasphalted residues or hydrotreated residues and the like.

All catalysts used for hydrogenolysis have a dual function of binding acid groups to hydrogeno groups. Acid groups have a large surface area (about 150 to 800 m ² · g ⁻¹ ) that shows acidity on the surface, such as halogenated alumina (specifically chlorinated alumina or fluorinated alumina), blends of boron and aluminum oxide, amorphous silica- Provided by a combination of alumina and zeolite. Zeolites are currently very expensive materials. Zeolites may be used alone or in admixture with an amorphous matrix. Hydrogen groups are selected from one or more of the Group VIII metals of the periodic table, for example nickel, palladium or platinum, or from Group VI metals of the periodic table, specifically molybdenum and tungsten, Group VIII metals of the periodic table, specifically cobalt and nickel It is provided by a combination of two or more metals.

Catalytic metals used in refining, hydrorefining or petrochemicals are most commonly oxidized, whether the catalysts are new or regenerated. However, such catalyst metals are often active or have high performance only in the sulfided or at least partially sulfided form, and therefore it is necessary for the purifier or petrochemical to carry out the vulcanization of the catalyst before use.

Regeneration of catalysts is currently being carried out more by specialists in catalyst regeneration, sometimes independent of industrial units, but it seems more reasonable for refiners to consider returning readily available products; This is to efficiently carry out the method of Applicant's European Patent EP-B-130850 (or US-A-4530917). In the process of this patent, when the sulfided compound is incorporated into the catalyst compound, vulcanization or prevulcanization of the catalyst occurs when the catalyst is subsequently contacted with hydrogen in the reaction zone (the zone treating the batch) or immediately near the reaction zone. Of course, the incorporation of the sulfided compounds may also be carried out in close proximity to the industrial unit or in the catalytic treatment zone, if necessary, and the incorporation of the sulfided compounds may be carried out in situ on a new catalyst or on a regenerated catalyst before using it as an industrial unit. Can be.

More specifically, the vulcanization process of the catalyst of the applicant's European Patent EP-B-130850 or US A 4530917 (method called SULFICAT) is a so-called incorporation of sulfide compounds having special properties into the catalyst compound. It features preliminary steps.

The preliminary step of introducing the sulfided compound may be randomly “off” regardless of whether it is close to the location of the industrial unit or somewhat geographically remote from the industrial unit (eg where the catalyst has been regenerated or where the catalyst is made). It is referred to as "site" or "ex-site" preprocessing. However, this method is in any case immediately near the reactor (optionally referred to as "in situ"). That is to say they are never carried out at the top of the reactors or in areas which are in some direct connection with these reactors and therefore at least in part imposed by the operating conditions of the reactors themselves or by the deposits of the reactors (eg the pre-hydrogen zones of the catalyst). It is necessary to carry out the work under (temperature, pressure, etc.).

In summary, Applicant's European Patent EP-B-130850 makes it possible to initiate a standard activation reaction above 100 ° C. in the presence of hydrogen when the catalyst is preferably started in situ, thus allowing the presence of hydrogen in situ. It relates to a method (called SULFICAT) which makes it possible to carry out vulcanization reactions at the required theoretical or non-theoretical rates of the active metal (s) which are part of the composition of the catalyst. This method consists in incorporating at least one organic polysulfide into the pores of a new catalyst or a regenerated catalyst in the absence of hydrogen.

Thus, the vulcanization reaction of the catalyst is carried out as follows: The first step is carried out in the same system without using hydrogen, in which the catalyst is treated with a vulcanizing agent which is partially or wholly incorporated into the pores of the catalyst. . Here, the vulcanizing agent is used as a solution in a solvent; The second step is carried out in series, preferably at 150 ° C. or higher, by which the step of activating the catalyst carried out using hydrogen is initiated and the metal (s) being part of the catalyst composition due to the presence of hydrogen The required amount of sulfur is fixed in the phase.

The second step described above is improved in patent EP-B-181 254 or US-A-4 719 195. The purpose of these two patents is to carry out pre-vulcanization of the catalyst in a homogeneous manner by incorporating only all the sulfur required and the amount of sulfur required by the user. Thus, the catalyst is fed to a purification unit or any other unit so preconditioned for the vulcanization reaction.

As such, in the case of a hydrogen catalyst, the purifier or any other user reacts sulfur on the metal contained in the catalyst, injects the batch to be treated, in the presence of hydrogen to initiate the purification reaction or the preservation reaction of the hydrocarbon. For example, the catalyst had to be reactivated at a temperature of 100 to 400 ° C.

Di-tert-dodecylpolysulfide (TPS 32 of ELF) is a preferred example of polysulfide. Di-tert-nonylpolysulfide (TPS 37 of ELF) is also an example thereof. For process reasons, it is clear that such vulcanizing agents, such as polysulfides, should be used alone or mixed with one another in carefully selected proportions.

The first step described above is carried out without the use of hydrogen and makes it possible to obtain the total or partial vulcanization degree required by the user with high accuracy. Such incorporation of sulfur is carried out at 0 to 50 ° C, preferably 10 to 35 ° C, more preferably at ambient temperature. Vulcanizers are used diluted in an appropriate solvent. Thus, the solvent selected may be used alone or in combination, and may be one of the following solvents:

* Light gasoline boiling at, for example, about 60-95 ° C.,

Hexane gasoline boiling at about 63-68 ° C.,

F-type gasoline boiling at about 100-160 ° C.,

"White spirit-type gasoline" boiling at about 150-250 ° C., or

* Any fraction which may or may not contain a hydrocarbon equivalent to the gasoline.

During the standard activation reaction carried out using hydrogen (second stage of the process of European Patent EP-B-130 850), it is specified at or below the work site (where the catalyst is used for the treatment of various batches). The vulcanizing agent introduced into the catalyst in an amount can produce hydrogen sulfide which, together with hydrogen, exothermic reactions (1), (2) and (3) of the following formulas relating to the vulcanization of molybdenum, cobalt and nickel Yield sulfur or sulfur of the desired metal (s) in the catalyst.

(1) MoO ₃ → MoS ₂

(2) 9 CoO → Co ₉ S ₈

(3) 3 NiO → Ni ₃ S ₂

In Applicant's EP-B-181 254 (or US-A 4719195), it was found that not only the presence of hydrogen is necessary in the first step of the second step, but also its absence is desired. The second process of the second step may be performed using hydrogen. Since the latter is generally carried out in situ, it can be combined with the initiation of a purification reaction or a petrochemical reaction to design the catalyst. In the first step of the second step it was found that the catalyst is vulcanized despite the absence of hydrogen. This phenomenon is confirmed by analysis of the catalyst which turns black. In contrast, the chemisorption test shows that the catalyst remains inactive without catalytic activity unless the catalyst continues to reach a constant temperature of 275 ° C. and remains at least 275 ° C. for at least a few minutes.

The above-mentioned SULFICAT method does not use organic polysulfide alone, but when mixed with a sulfur element in a critical amount, the applicant's patent EP-B-130 850 (US-A-4530917) and EP-B It was improved after finding that the quality of the method described in -181254 (US-A-4719195) was further improved. A process in which the preparation of the catalyst uses solely sulfur elements in sulfur is disclosed in patent US A 3177136 (Herrington). However, the results here are accurate but very disappointing. In US-A-3177136, the catalyst is prevulcanized with molten elemental molten at 100 to 150 ° C, preferably 110 to 130 ° C, without using hydrogen. This prevulcanized catalyst is treated in the presence of hydrogen to transform the elemental sulfur into H ₂ S at 200 to 600 ° C.

However, although it is not recommended in the end because of too fast start-up, clogging, etc., the use of elemental sulfur alone is interesting, but the rise of non-coordinated prevulcanization when using elemental sulfur in combination with organic polysulfides. Provide action. This improved technology of the Applicant is called SUPER PLUS and is disclosed in EP-B-448435 or US-A-5,139,983. The elemental sulfur is used in the form of molten sulfur, sulfur powder or sulfur powder according to any suitable method, for example the method disclosed in the applicant's patent EP-B-153233.

The methods were the subject of another type of improvement method of the applicant, which method was described in EP-B-466 568 (US-A-5153163) called "SURECAT". A preliminary vulcanization process of catalysts with passivation) is provided. Indeed, in the catalytic and petrochemical sectors, in specific examples of catalytic reforming or selective hydrogenation of gasoline, it is often appropriate to reduce the activity of catalysts containing metals such as platinum, palladium, rhenium, iridium, tin and nickel. have. Catalysts containing nickel are referred to as excellent catalysts for the hydrogenation of aromatic compounds, but lead to departures during the start-up of new catalysts or regenerated catalysts, and even lead to start-up abnormalities and destruction of reactors. Therefore, it is necessary to start the surface stabilization treatment which can prevent the detachment. This treatment generally consists of irreversibly destroying the activity using sulfur on the most active nickel sites present on the new or regenerated catalyst.

The aim of the improvement of SURECAT is to enable the improvement of the prior art and to work under simplified conditions which give the refiner less restrictions. According to "Surecat", (a) impregnating the catalyst with a sulfur compound and (b) reducing the catalyst are carried out simultaneously. Reduction of the catalyst is also carried out using a reducing organic compound, ie in the absence of fresh hydrogen. The reducing organic compound is advantageously selected from the reducing compounds disclosed in EP-B-303,525 of the applicant. Preferred compounds include formic acid (HCOOH), methyl formate (HCOOCH ₃ ) and ethyl formate (HCOOC ₂ H ₅ ).

In another method of the Applicant disclosed in EP-B-564 317, the preliminary vulcanization of the catalyst is carried out in the presence of at least one organic polysulfide or in the presence of elemental sulfur or at least one organic polysulfide and elemental sulfur. By the same time. Preference is given to using a mixture of at least one organic polysulfide and elemental sulfur. As the solvent, white spirit or a similar solvent is generally used, and these are preferable.

In conventional methods, significant exothermic effects have sometimes been observed during the start-up phase of the catalyst in the purification unit, which can reduce the exothermic effect. The presence of the exothermic reaction in the reactor can be removed or reduced by working according to the novel improved process of this invention. This method does not use white spirit alone as a solvent, but rather a suitable mixture of white spirit (or similar solvent) with one or more compounds or components comprising carbon-bearing bonds, such as triglyceride bonds, specific examples of olefinic bonds. It consists of using. This method allows sulfur to pass through the pores of the catalyst by decomposition.

In order to achieve such an improvement, the catalyst is contacted with a liquid and a sulfur element containing a vulcanizing agent of the organic polysulfide group, a solvent or related solvent such as white spirit, and a compound such as olefin, while removing the solvent. On the other hand, the mixture is heat treated, in particular for the purpose of causing a coupling reaction between the elemental sulfur and the double bond of the olefinic compound. The heat treatment is carried out at a temperature of at least 100 ° C, preferably at least 120 ° C. In this way the elemental sulfur is partially or completely bonded in the form of polysulfide.

Other patents, specifically US Pat. No. 5,215,954, can also incorporate elemental sulfur into the pores of the catalyst, but this method relates to the preliminary vulcanization of the catalyst by a method in which elemental sulfur basically penetrates into the pores by melting or sublimation. will be.

Subsequently, attempts have been made to improve the technique of prevulcanizing the catalyst when using a catalyst that overcomes certain limitations. A method of prevulcanizing a catalyst called bi-phase is disclosed in EP-B 628347 of the applicant, which comprises: (a) at least one primary sulfiding compound having a decomposition point T1 of less than 220 ° C .; (b) The use of a prevulcanizing agent containing at least one secondary sulfiding compound having a decomposition point T2 of about 220 ° C. or more. These methods are all subject to Applicant's further refinement process which pre-vulcanizes a substantial portion of the catalyst described above. This improved process, called TOTSUCAT, is disclosed in French Patent Application No. 94/12096, which specifically includes a vulcanizing agent selected from the group consisting of elemental sulfur and organic polysulfides into hydrocarbon treatment catalysts, and rather large Incorporating a portion into the pores of the catalyst, the incorporation being carried out in the presence of a olefin or an olefinic fraction, for example a component such as vegetable oil, or a solvent partially or completely containing similar components, Treating the silver catalyst with hydrogen at 150 to 700 ° C. and an oxidative surface stabilization step.

The present invention is particularly an improvement for both "co-independent" or "non-co-independent" vulcanization methods or pre-vulcanization methods of catalysts used in purification / petrochemicals. The invention also relates to a process for incorporating sulfur into the pores of a catalyst. Sulfur introduced into the catalyst is bonded to the active metal of the catalyst (molybdenum, tungsten, nickel, cobalt or other metals). This means that even at high temperatures, most of the sulfur remains in the catalyst when it is leached by extraction with a solvent. Sulfur may be introduced in the form of hydrogen sulfide by the process according to the invention in a single step, but may also be introduced in the form of elemental sulfur or any other sulfur compound. In the practice of the present invention, the presence of pure hydrogen or dilute hydrogen is required to help the hydrogen sulfide penetrate the catalyst mass. If it is not fresh hydrogen sulfide, elemental sulfur or sulfide compounds are used to convert at least a substantial portion of elemental sulfur or sulfide compounds into hydrogen sulfide. Sulphide compounds that can be used are all sulfide compounds which can be decomposed into hydrogen sulfide under hydrogen, for example sulfur elements, mercaptans, sulfides, oxygen compounds of sulfide or sulfur, and organic polysulfides. The process is also preferably carried out in a fluidized bed or similar bed, and in contrast is characterized by the fact that the vulcanization reaction takes place outside of the end-use position, i.e. outside of the hydrocarbon hydrogen conversion reactor (incoherent).

The invention can be carried out at 80 to 450 ° C., preferably 110 to 400 ° C. in one or more steps, including for example a single step. The present invention is carried out in one step especially when the sulfide compound is hydrogen sulfide. In this case, the contact between the catalyst compound, hydrogen sulfide and hydrogen in the state where there is a possibility of the presence of water vapor is mainly done in the operation performed at a relatively low temperature. This method can be carried out in the presence of moisture. The presence of water vapor can improve the quality of the vulcanization reaction in the case of operations carried out at low temperatures of mainly 80 to 250 ° C, preferably 100 to 200 ° C.

The present invention may also be practiced in one step if a sulfide compound to be immediately decomposed into hydrogen sulfide instead of hydrogen sulfide is introduced into the mixture or simultaneously with hydrogen. Such sulfide compounds are selected from the group consisting of mercaptans, sulfides, disulfides, polysulfides and oxidizing compounds of sulfur. For example, butyl mercaptan; Dimethyl sulfide; Dimethyl disulfide; Butyl, octyl or nonyl polysulfide; Dimethyl sulfoxide; Sulfolane;

The invention can also be practiced in two steps. In the first step, the catalyst compound is thoroughly mixed with elemental sulfur or sulfide compounds (except hydrogen sulfide) in the absence of hydrogen. It is possible to work in the presence of the solvents mentioned above, in particular white spirits, in the disclosure of the prior art.

Optionally, olefin oil or vegetable oil can be added to the white spirit in one step. This contact is made, for example, at 10 to 320 ° C., preferably at 80 to 250 ° C., whereby sulfur or sulfide compounds (other than hydrogen sulfide) are incorporated into the pores of the catalyst.

It may work in the presence of water vapor and / or in the presence of an inert gas. It is preferable to work in the presence of an inert gas.

The second step may optionally be performed in the zone where the first step is performed. However, the second step is usually carried out in a zone separate from the zone in which the first step is carried out.

In the second step carried out at the aforementioned temperature range, for example 80 to 450 ° C., more specifically 110 to 400 ° C., the catalytic compound in which sulfur is incorporated is contacted with hydrogen in the selective presence of water vapor. In this step, hydrogen sulfide is formed and a reaction takes place between the catalytic metal oxide and the initial hydrogen sulfide, i.e. hydrogen sulfide formed in situ, during which the sulfur is bonded to the catalyst.

When using the two-step method, the first step is a sulfide of metals deposited on the surface of the catalyst, ie more than half to equivalent amounts of sulfur corresponding to the theoretical amounts of MoS ₂ , WS ₂ , Ni ₃ S ₂ and Co ₉ S ₈ Sulfur may be incorporated.

Whether the operation is carried out in one or two stages, the reaction between hydrogen sulfide and oxides is summarized as follows:

MoO ₃ + 2H ₂ S + H ₂ → MoS ₂ + 3H ₂ O

WO ₃ + 2H ₂ S + H ₂ → WS ₂ + 3H ₂ O

3NiO + 2H ₂ S + H ₂ → Ni ₃ S ₂ + 3H ₂ O

9CoO + 8H ₂ S + H ₂ → Co ₉ S ₈ + 9H ₂ O

The process according to the invention allows the hydrogen / hydrogen sulfide mixture, which may contain an inert gas, to react directly with the catalytic metal oxide, which mixture is introduced directly into the reaction system, or preferably with any suitable compound containing hydrogen and hydrogen, It is characterized in that formed in situ by the reaction of.

The formation of hydrogen sulfide by the reaction of hydrogen and the sulfide compound is indicated differently depending on the type of the compound as illustrated below.

Elemental sulfur: S + H ₂ → H ₂ S

Dimethyl disulfide: CH ₃ -SS-CH ₃ + 3H ₂ → 2CH ₄ + 2H ₂ S

Dioctyl polysulfide: C ₈ H ₁₇ -S ₅ -C ₈ H ₁₇ + 6H ₂ → 2C ₈ H ₁₈ + 5H ₂ S

Dimethyl sulfoxide: CH ₃ -SO-CH ₃ + 3H ₂ → 2CH ₄ + H ₂ S + H ₂ O

Later in the one-stage or two-stage reaction, the catalyst is purged under an inert gas to remove at least partly the hydrogen present in the pores and generally at least partly hydrogen sulfide. In general, it is appropriate to remove almost all residual hydrogen and hydrogen sulfide.

One of the aspects of the present invention is to carry out the vulcanization reaction of the catalyst on a non-identical basis, i.e., at a position separate from the position at which the catalyst is used for the conversion of the petroleum batch or the hydrogen conversion function. This specific embodiment provides various advantages, not only because the catalyst charged into the unit already contains the required amount of sulfur, but also because the catalyst is already activated and already ready to be used as an active catalyst. This specific embodiment greatly simplifies the start-up process and thus saves valuable time for the user of the purification catalyst unit.

In another aspect of the invention, unlike the prior art, it is preferred that the vulcanization reaction takes place on a catalyst operating in a sulfur incorporation zone. The activation reaction therefore takes place when the catalyst is running.

For example, it is possible to use a sedimentary bed in which solids slowly descend by gravity along a tube or ring, a fluidized bed or bed in which solids are raised by a high velocity air stream, or a bed or fluidized bed circulating in a belt furnace or a rotary furnace. have. The layer may be expanded or foamed.

Unless judging in advance the more advanced scientific theories, this mobility of the catalyst during the sulfur type formation step ensures homogeneous treatment and thus high quality.

Indeed, the problem with the potential of the fixed bed is that there is a preferred route, which yields an area in which the catalyst is exposed to an inappropriate amount of sulfur compared to the theory required. Another potential problem with the fixed bed is that it is also relatively difficult to remove the heat generated by the exothermic vulcanization reaction. For both examples, it is advantageous to stir the catalyst continuously. Therefore, when these methods are carried out in one or two stages, it is preferable to carry out the operation using the catalyst layer in operation. When the process is carried out in two stages and preferably in two separate zones, a catalyst operating in the first stage or in the second stage, or preferably in each of the two layers of the two stages, is used. It is preferable to work by.

Typical embodiments of the process according to the invention comprise the step of transporting catalyst particles into a heated furnace, preferably a heated rotary furnace, wherein the temperature of the particles in the furnace is at least 120 ° C, for example up to 120-200 ° C. Is increased. The particles are then contacted by spraying with molten elemental sulfur at a temperature ranging from 120 to 160 ° C. In a second step carried out in the same or different (rotary) furnace, the molten sulfur impregnated particles are hydrogen or hydrogen at a temperature of about 80 to 450 ° C., preferably 110 to 400 ° C., more preferably 250 to 400 ° C. -Contact with the containing gas. Those skilled in the art will understand that it is desirable that the temperature of the catalyst particles not be lowered between the first and second steps. Following the hydrogenation step, the particles are removed from the furnace and allowed to cool.

The following examples illustrate the invention.

Example 1

The catalyst was prevulcanized with a H ₂ S / H ₂ O / H ₂ mixture. The work was carried out in one step. Commercially available catalysts such as CoMo on alumina (HR 306 of Procatalyst Company) were charged with H ₂ S / H ₂ O containing 15 vol% H ₂ S, 15 vol% H ₂ O, and 70 vol% H ₂ . Treated with a / H ₂ mixture. Water was injected into the gas circuit using a liquid pump. The reactor is a continuous rotation system with a dwell time of about 80 minutes at the indicated temperature. In this example, the temperature is 110 ° C. Cooling was carried out under hydrogen and then under nitrogen. In this way, catalyst A was obtained. Sulfur content is, of course, solid phase pre-washed in hot toluene in a Soxhlet apparatus. Assay on catalyst A. Vulcanization was evaluated by comparing the levels of hexavalent molybdenum and tetravalent molybdenum by X photoelectron spectroscopy. Mo ⁺ 4, whereas the correspond to the types of sulfur to molybdenum MoS ₂ ⁺ 6 correspond to the oxide type already present on the new catalyst. The results are shown in Table 1.

Example 2

Catalyst B was obtained in the same manner as in Example 1 except that the temperature was 300 ° C instead of 110 ° C.

Example 3

Catalyst C, but is the same as in Example 1 to yield at 110 ℃, the gas mixture does not contain a H ₂ O, H ₂ O was replaced by an inert gas stream. The gas composition consisted of 15% H ₂ S, 15% N ₂ , 70% H ₂ .

The primary test results of the three examples performed in the presence of pure hydrogen sulfide indicate that a temperature of 110 ° C. is sufficient to initiate a significant vulcanization reaction of the catalyst, and the gas preferably contains a constant partial pressure of water vapor. If this is not true, the theoretical level, ie the vulcanization level indicated by the Mo ⁴⁺ / Mo ⁶⁺ ratio, may appear to be inadequate, but even at temperatures of 300 ° C. it can yield much higher vulcanization levels ( Shown in Example 8).

Example 4

The catalyst was prevulcanized with elemental sulfur and then activated at 300 ° C. under hydrogen (2-step process).

Commercial catalysts such as CoMo / alumina were mechanically mixed at normal temperatures with elemental sulfur having an average particle size of less than 5 microns. 100 g of catalyst were mixed with 21.6 g of sulfur suspended in 45 ml of white spirit (initial and final boiling points were 140 ° C. and 180 ° C., respectively). This amount of sulfur corresponds to a theoretical amount of 200% for MoS ₂ / Co ₉ S ₈ . This catalyst (second step) was then introduced under the pure hydrogen atmosphere into the same rotary system as in the above examples. The residence time at a temperature of 300 ° C. was 80 minutes. Analysis of the corresponding catalyst is shown in Table 1 (catalyst D). The vulcanization level of the catalyst is accurate and sulfur is not very extractable in toluene, indicating that the sulfur present is basically sulfur bound and not simply deposited. At this time, a leaching operation was performed as a test for observing whether sulfur actually attached (bonded) to the catalyst. Here, extraction was performed with toluene.

Example 5

Example 5 was carried out similarly to the example described above, except that the air stream consisted of a hydrogen / water mixture with 80% by volume of hydrogen. 20% water volume was regenerated by the liquid water injection pump. Let this be catalyst E. Analysis showed that catalyst E did not differ much from catalyst D.

Example 6 (different from hydrogen in the second step)

Example 6 was carried out analogously to Example 4 by replacing the hydrogen / nitrogen stream with an 80/20% by volume nitrogen / water stream according to Table 1. The vulcanization level on the crude catalyst was reduced, especially on the leached catalyst, indicating that sulfur was not bound to the catalyst.

Example 7

The catalyst was prevulcanized with organic polysulfide (first step) and then activated under hydrogen (second step).

The same alumina phase catalyst CoMo as used in the above examples was impregnated with a solution of di-tert-nonyl polysulfide mixture dissolved in white spirit. 31 g of di-tert-nonyl polysulfide (37 wt% sulfur content of Atochem's TPS 37) mixed with 18 ml of white spirit used in the above examples was added to 100 g of catalyst. The catalyst was stirred at normal temperature for 10 minutes to obtain a homogeneous suspension. This suspension was heat treated at 120 ° C. under nitrogen to remove the organic solvent bulk. Thereafter, the catalyst was fed to a rotary furnace under a stream of hydrogen (second stage). The residence time at a temperature of 300 ° C. was about 80 minutes. The vulcanization level of the solid (catalyst G) obtained before and after washing with toluene was high, indicating that the sulfur is well fixed and the reduced molybdenum is in the ⁴⁺ stage. In conclusion, the process from Examples 4, 5, 6 and 7 can be carried out as a two-step, i.e. by incorporating sulfide compounds into the catalyst and subsequent activation steps.

Example 8

This example performs the operation in the absence of water vapor, except that the treatment atmosphere is a mixture of H ₂ / H ₂ S (15% H ₂ S and 85% H ₂ ) at 300 ° C. and in a rotary furnace. , As specified by the present invention, and the same as in Example 2. The amount of hydrogen sulfide used is theoretically 1.5 times the amount needed to produce MoS ₂ / Co ₉ S ₈ . Cooling under hydrogen and purging under nitrogen yielded catalyst H (catalyst H proved to be better prevulcanized than in similar Example 3 where the temperature used was only 110 ° C).

Example 9

Pure hydrogen was used in this example. Gas phase hydrogen sulfide was replaced by injection of dimethyl disulfide in the hydrogen circuit. The amount of sulfur injected in DMDS form was 1.5 times the theoretical amount of MoS ₂ / Co ₉ S ₈ . The residence time at 300 ° C. was 80 minutes as in the above example. Cool under hydrogen and purge under nitrogen to afford catalyst I.

Example 10

As well as the reference CoMo novel catalyst (HR306 from Procatalize), the H type catalyst was in turn charged into the catalyst test unit. Hydrogen desulfurization of atmospheric gas oil using three catalysts under a batch with a pressure of 60 b, a temperature of 340 ° C., a volumetric rate of 2 h ⁻¹ per hour and a sulfur content of 1.23% pds, an initial point of 225 and an end point of 392 ° C. Test in reaction.

The start-up process was different for the three catalysts, the first two were already pre-vulcanized and activated and the third was also an oxide. The third catalyst actually transformed it to catalyst J using the following procedure. The increase in temperature was made up to 220 ° C. at a rate of 5 ° C./min under hydrogen, at which point a 1 hour plateau was observed.

A dimethyl disulfide injection circuit was operated to add 1.6 g of sulfur (S) per hour through a DMDS solution diluted 10% in naphtha at the beginning of the plateau. After 1 hour in the plateau, the injection rate was reduced to 1.2 g of S per hour and the rate of temperature rise was restarted at 1 ° C./min to 300 ° C., where 80 minutes of plateau was observed. The infusion of DMDS was then stopped. This corresponds to the end of the activation process of catalyst J, where the amount of DMDS corresponds to 1.5 times the theoretical amount of sulfur.

Thereafter, the temperature was lowered to 200 ° C, atmospheric gas oil was injected, and the temperature was raised to 340 ° C at a rate of 2 ° C / min. The performance of the hydrodesulfurization reaction was measured 12 hours after stabilization.

Regarding the case of catalysts H and I, the process does not include a vulcanization reaction, the temperature is simply raised to 200 ° C. at a rate of 5 ° C./min, the gas oil is injected at 200 ° C., and the temperature is again brought to 2 ° The temperature was raised to 340 ° C./min, where HDS levels were measured after 12 hours. The results are shown in the last row of Table 1 below. From this table it can be seen that the two products pre-vulcanized outside the test unit and in the fluidized bed show very clear advantages compared to the pre-vulcanized catalyst in the fixed bed.

TABLE 1

The vulcanization reaction of the catalysts according to the invention can be carried out in the same system, which saves valuable time for the user of the purification catalyst unit since it greatly simplifies the start-up process. In addition, the vulcanization reaction according to the present invention can take place in the catalyst in operation to ensure homogeneous treatment and high quality.

Claims (21)

A method of incorporating sulfur into the pores of a hydrocarbon conversion catalyst containing at least one Group VI or Group VIII metal of the Periodic Table of the Elements, the catalyst is used in the form of a catalyst layer in which the catalyst moves within a zone in which sulfur is incorporated, which is hydrogen sulfide present. Ha; Or in the presence of hydrogen to off-site in the presence of a sulfur compound capable of decomposing to hydrogen sulfide in the presence of hydrogen, and the process is carried out in a one-step reaction at a temperature of 80 ° C to 450 ° C; Or a first step of mixing sulfur elements other than hydrogen element, hydrogen sulfide, or both in the form of a catalyst layer in which the catalyst moves, at a temperature of 10 to 320 ° C. without hydrogen, and in the form of a catalyst layer in which a catalyst mass containing sulfur is transferred in this step. Contacting hydrogen at 80 to 450 ° C. to form hydrogen sulfide first, followed by a two step reaction consisting of a second step of reacting the initial hydrogen sulfide with a metal oxide of the catalyst. The process according to claim 1, which is carried out in one step or two step reaction in the presence of hydrogen sulfide. The process of claim 1, wherein the one step reaction is carried out at 110 to 400 ° C. 3. The process according to claim 3, which is carried out in gas phase in the presence of water vapor. The process according to any one of claims 1 to 3, wherein the second stage of the one-stage reaction or the two-stage reaction is carried out in the absence of water vapor at a temperature of 250 ° C to 450 ° C. The method of claim 1 wherein the catalyst bed is selected from the group consisting of a fluidized bed, a circulating bed, a fluidized bed, an expanded bed, a boiled bed, a belt bed or a rotating bed. The method of claim 1, wherein the sulfur compound is selected from the group consisting of sulfur elements, mercaptans, sulfides, disulfides, polysulfides, and sulfur oxide compounds. The method of claim 7, wherein the sulfur compound is butyl mercaptan; Dimethyl sulfide; Dimethyl disulfide; Butyl, octyl and nonyl polysulfides; Dimethyl sulfoxide and sulfolane. The process of claim 1, wherein the process is carried out in a two stage reaction and the first stage is carried out in the presence of water vapor. 10. The method of claim 1 or 9, wherein the process is carried out in a two stage reaction and the first stage is carried out in the presence of an inert gas. 10. The process according to claim 1 or 9, which is carried out in a two step reaction and the first step is carried out in the presence of a solvent. The process of claim 1 or 9, wherein the process is carried out in a two-step reaction and the first step is carried out at 80 to 250 ° C. The method of claim 1, wherein the second step is carried out in a two-step reaction and the second step is carried out in the zone in which the first step is carried out. The method of claim 1, wherein the second step is carried out in a two step reaction and the second step is carried out in a zone separate from the zone in which the first step is carried out. The method according to claim 13 or 14, wherein the temperature in the second step is 110 to 400 ° C. The method of claim 15, wherein in the second step, the operation is carried out in the presence of water vapor. 10. The process according to claim 1 or 9, comprising at least half to the same amount of sulfur, which is carried out in a two-step reaction and which corresponds to a theoretical amount of sulfides of the metals deposited on the surface of the catalyst in the first step. How to. 10. The process of claim 1 or 9, wherein at the end of the process the catalyst is purged under inert gas to remove at least some of the residual hydrogen sulfide. 19. The method of claim 18, wherein almost all hydrogen and hydrogen sulfide are removed. 12. The method of claim 11, wherein the solvent is a white spirit with the addition of olefin oil or vegetable oil. The method of claim 11, wherein the solvent is an olefinic compound.