JPH11253805A - Production of presulfurized catalyst - Google Patents

Abstract

PROBLEM TO BE SOLVED: To use a catalyst even for desulfurization of a fluid containing a minute amt. of polycyclic sulfur compds. by heating and sulfurizing a catalyst preliminarily containing a sulfurizing agent in the pores of its surface in a hydrogen gas atmosphere in such a manner that the system is heated stepwise to the temp. at which hydrogen sulfide is produced. SOLUTION: At least one kind of sulfurizing agent is dissolved in a proper solvent such as CS2 and acetone, to which a catalyst to be presulfurized is added and stirred. The mixture is heated to remove the solvent and to impregnate the catalyst with the sulfurizing agent. Then the catalyst impregnated with the sulfurizing agent is put in a presulfurizing device such as an autoclave or a direct hydrogenation device, heated and presulfurized under pressure while introducing a hydrogen gas. In this sulfurizing process, the system is heated stepwise to the temp. at which hydrogen sulfide is produced. When a sulfur compd. expressed by the general formula of R-Sn-R' is used as the sulfurizing agent, the system is heated. for example, up to 190 deg.C for presulfurization at which the sulfurizing agent to be used reacts with hydrogen to produce hydrogen sulfide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a presulfurized catalyst used for hydrodesulfurization of gas oil or the like, and more particularly to a method for preparing a liquid containing a polycyclic sulfur compound which has been difficult to remove. The present invention relates to a method for producing a presulfurized catalyst suitable for desulfurization.

[0002]

2. Description of the Related Art In recent years, the consumption of white oil such as light oil has rapidly increased, so that air pollution particularly in metropolitan areas has become serious. Generally, gas and liquid products obtained from heavy carbon sources such as petroleum and coal contain large amounts of sulfur compounds and nitrogen compounds. That is being done. Examples of the catalyst used in the above-mentioned hydrogenation treatment include, for example, a non-acidic carrier such as alumina or silica on a non-acidic carrier selected from the group consisting of molybdenum, cobalt, tungsten and nickel, and elements VI and VIII of the Periodic Table of the Elements. Those which carry 0.2 to 30% of a group or other at least one active metal are usually used.

[0003] The catalyst used in this case is presulfurized with a mixture of hydrogen and hydrogen sulfide for several hours at a higher temperature than the hydrodesulfurization reaction. Preliminary sulfurization using a mixed gas of hydrogen sulfide and hydrogen is simple, but has the disadvantage that abnormal temperature rise is likely to occur because sulfurization is an exothermic reaction. Therefore, in recent years, using light oil to which a sulfur compound such as CS ₂ or mercaptan which is easily desulfurized is added,
Presulfurization under pressure has been performed.

[0004] However, the above-mentioned CS ₂ and mercaptans are also environmentally unfavorable, and dimethyl disulfide (DMDS) has been used.
S is also not a good presulfurizing agent because it is a volatile presulfurizing agent with a bad smell, high toxicity and low flash point. Such disadvantages are represented by the general formula R-Sn-R '(wherein n is an integer from 3 to 20, the group R' is a hydrogen atom or another group the same or different from the group R, and R and R 'are Saturated or unsaturated, straight-chain or branched, selected from naphthenic alkyl, aryl, alkylaryl and arylalkyl groups). It was done (Tokuhei 6-246)
No. 38).

In Japanese Patent Publication No. 6-24638, as a first step, at least one sulfurizing agent represented by the above-mentioned general formula R-Sn-R 'is used, After treating the catalyst in the absence and, if necessary, drying, the second step is (a) in the absence of hydrogen, in the presence of an inert gas or a non-inert gas, for at least about 5 minutes at 65-65.
A pre-sulfurization process is disclosed which comprises treating at 275 ° C. under a pressure of about 0.5 to 70 bar and then (b) at least 275 ° C. in the presence of hydrogen for at least about 1 minute when using the catalyst.

[0006] The first step in the presulfurization method is as follows:
The second step (a) is to introduce a sulfurizing agent partially or completely into the pores of the catalyst. The second step (a) is to convert an active metal oxide into a sulfide, and the (b) step is And imparting catalytic activity to the sulfide. According to this method, the catalyst that has been completed up to the first step or the second step (a) is not active at that time, so that it is easy to handle, and it is particularly necessary to perform hydrodesulfurization on various routes. While there is an advantage that it can be transported without the need for attention,
There was a disadvantage that the process was rather complicated.

[0007]

The present inventors have conducted intensive studies to solve the above-mentioned drawbacks. As a result, after introducing a sulfide agent into the pores of the catalyst, the sulfide agent is preliminarily sulfurized in a pressurized hydrogen atmosphere. The present invention has been found to be effective for deep desulfurization of gas oil and to be applicable to fixed-bed and boiling-bed reactors. Therefore, an object of the present invention is to have high activity as a hydrodesulfurization catalyst and to be effective for desulfurization of a liquid containing a trace amount of a polycyclic sulfur compound, such as dibenzothiophenes, which has been difficult to remove by conventional methods. An object of the present invention is to provide a method for producing a presulfurized catalyst.

[0008]

SUMMARY OF THE INVENTION The above objects of the present invention are as follows.
A method for producing a preliminary sulfurization catalyst used in a hydrodesulfurization reaction, comprising heating a catalyst containing a sulfurizing agent in advance in pores on the surface thereof in a hydrogen gas atmosphere to generate hydrogen sulfide at the time of sulfurization. This has been achieved by a method for producing a pre-sulfurized catalyst, wherein the temperature in the system is increased stepwise until heating.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The catalyst to be presulfurized in the present invention is used in a hydrodesulfurization reaction. For example, a non-acidic carrier is selected from precious metals such as Pt and Pd and other active metals. At least one active metal belonging to Group VI or VIII of the periodic table is supported by 0.2 to 30%.

As the other active metals, cobalt, molybdenum, nickel and tungsten are preferable, and a combination of two metals such as cobalt-molybdenum, nickel-molybdenum and nickel-tungsten is particularly preferable. The presulfurized forms of these catalysts are:
For example, Co ₉ S ₈ , MoS ₂ , WS ₂ , Ni ₃ S ₂ , RuS
Contains about 50-110% of the sulfur stoichiometry, calculated as the amount of sulfide, such as _2-x (0 ≦ x <2). These catalysts are used by being supported on a non-acidic carrier. Examples of the non-acidic carrier include alumina, silica, silica-alumina, silica-magnesia, fluorinated silica, boron-alumina, clay, activated carbon, and fluorinated alumina.

The sulphiding agent used in the present invention can be appropriately selected from known sulphiding agents, and it is preferable to use a sulfur-containing compound represented by the general formula R--Sn--R 'in addition to sulfur. Is preferred. Here, n is 1 to 10, preferably 3
To 7, particularly preferably a number of 4 to 6. R and R 'are organic groups, and the total of carbon atoms of R and R' is 2-150
Is particularly preferable, and it is particularly preferably 4 to 60, and most preferably 8 to 20.

Specific examples of the organic group include a saturated or unsaturated alkyl group, aryl group, alkylaryl group, arylalkyl group and the like, which may be chain-like or branched. In the present invention, particularly preferred as a sulfurizing agent include _{C 8 H 17 -S 4.8 -C 8} H 17 ( Dainippon Ink Co., Ltd. CS-40).

In the present invention, by dissolving at least one sulfiding agent in a suitable solvent such as CS ₂ and acetone, and stirred with the catalyst to be pre-sulfurized, heated to remove the solvent, sulfurizing agent To the catalyst. Next, the catalyst impregnated with the sulfurizing agent is put into a pre-sulfurizing device such as an autoclave or a direct hydrotreating device, and pre-sulfurized by heating while flowing hydrogen gas under pressure. The pressure of the hydrogen gas in this case is ^{10kg / cm 2 ~50kg / cm 2} , 2
It is preferable that the ^{0kg / cm 2 ~40kg / cm 2} . Further, the flow rate of the hydrogen gas can be appropriately set,
For example, it may be 60 ml / min.

In the present invention, as the liquid to be subjected to the pre-sulfurization reaction, any known and common oil containing a sulfur component can be used. Examples of such a liquid include oils such as light oil, heavy oil, and gasoline. Sulfur compounds other than polycyclic sulfur compounds can often be desulfurized relatively easily by conventional desulfurization reactions. The presulfurized catalyst obtained in the present invention is suitable for hydrodesulfurization of sulfur compounds, which are relatively difficult to desulfurize with conventional catalysts, among various sulfur compounds. In other words, the pre-sulfurization catalyst obtained by the production method of the present invention exerts a more excellent effect in hydrodesulfurization reaction for a liquid containing a polycyclic sulfur compound, and particularly, a light oil containing dibenzothiophenes. It exhibits the best effect in hydrodesulfurization reaction for.

The present invention is characterized in that the system is heated stepwise to a temperature at which hydrogen sulfide is generated during sulfurization. When a sulfur compound represented by the general formula R-Sn-R 'is used as a sulfidizing agent,
What is necessary is just to raise the temperature to the temperature at which the used sulfide agent reacts with hydrogen to become hydrogen sulfide. This temperature is, for example, the aforementioned CS-
In the case of 40, the temperature is about 190 ° C. When the catalyst to be presulfurized is, for example, Co-Mo, the sulfuration of Mo is R-
Although it can be sufficiently carried out using a sulfur compound represented by Sn-R ', the preliminary sulfuration of Co may be insufficient in some cases.

In such a case, R-
It is preferable to use a plurality of types of sulfurizing agents, such as using sulfur or another sulfurizing agent together with the sulfur compound represented by Sn-R '. When multiple sulphiding agents are used, the temperature is increased step by step so as to react with hydrogen at each appropriate temperature to generate hydrogen sulphide according to the difference in decomposition temperature of each sulphiding agent. It is necessary to go.

Even when a sulfur compound represented by R-Sn-R 'and sulfur are used in combination as a sulfurizing agent, the sulfur compound is represented by R-Sn-R' until the sulfuric agent is impregnated into the catalyst metal. This is the same as the case where only a sulfur compound is used, but in this case, first, the temperature is raised to 160 ° C. to 220 ° C. to react R—Sn—R ′ with hydrogen to generate hydrogen sulfide. Presulfurizes metals that can be sulfided with hydrogen sulfide. Such a metal is, for example, the Mo metal in the above-mentioned Co-Mo system.

Then, the temperature is raised to 390 ° C., and the unsulfurized metal is presulfurized by hydrogen sulfide generated by the reaction between the carrier sulfur and hydrogen. In the case of preliminary sulfurization at such a high temperature, it is preferable to appropriately flow a liquid substance such as light oil in order to treat the heat generation and prevent overheating of the catalyst layer. The metal to be sulfided in the second heat treatment is, for example, Co
-Co metal in Mo system.

The heating rate at the time of heating is not particularly limited, and can be appropriately set depending on energy cost, durability of the apparatus, etc., but a multi-step heating may be performed according to the number of sulfide agents used. is necessary. For example, the first-stage heating is performed at 160 ° C. to 220 ° C. for 30 minutes to 2 hours, and the second-stage heating is performed at 390 ° C. for 30 minutes to 2 hours. What is necessary is just to set suitably based on the kind of a sulphidizing agent, the kind of a catalyst, the quantity of the sulphidating agent impregnated in a catalyst, etc.

The catalyst presulfurized by the method of the present invention is particularly effective for desulfurizing liquids containing sulfur such as dibenzothiophenes, which have been difficult to remove by conventional hydrodesulfurization reactions. However, it may be used in hydrocarbon conversion reactions such as hydrogenation, dehydrogenation, alkylation, and isomerization.

[0021]

According to the presulfurization method of the present invention, the hydrogen sulfide concentration around the catalyst at the time of sulfurization is significantly higher than that in the case of using the conventional hydrogen-hydrogen sulfide mixed gas. The amount of sulfur to be used can be smaller than before. Further, since the sulfidation temperature can be lowered, the use of a sulfidizing agent can be reduced, and the temperature control during sulfidation is easy. Further, the obtained presulfurized catalyst is effective for removing the remaining polycyclic sulfur compounds which cannot be removed by the conventional hydrodesulfurization reaction, and thus is suitable for obtaining high-quality white oil.

[0022]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto.
In each of the catalysts used in the examples and comparative examples, the alumina (Al ₂ O ₃ ) support was 4.3 wt% as CoO,
Co-Mo so that the content of oO ₃ becomes 17.1% by weight.
And 2.54 g of each was used.

EXAMPLE 1 1.27 g CS-40 and sulfur
1.27 g CS_TwoDissolve in 5 ml, add catalyst and stir
Irradiate an infrared lamp with stirring (50 ° C, 1 hour)
Solvent CS_TwoThe CS-40 and sulfur obtained by removing
Is packed in a fixed bed reactor at a pressure of 30k.
g / cm^Two , Hydrogen gas atmosphere with a hydrogen gas flow rate of 60 ml / min
Preliminary sulfurization is performed in the air according to the temperature program shown in Fig. 1.
Was. CS-40 decomposes at 150 ° C.
At 0 ° C, the reaction between sulfur and hydrogen contained in CS-40
Mo is sulfurized with hydrogen sulfide generated by
The temperature is raised to 390 ° C while flowing oil,
Sulfurizes Co with hydrogen sulfide generated by the reaction between yellow and hydrogen,
The catalyst was almost completely sulfurized.

Example 2 2.0.60 g of CS-40 and 0.47 g of sulfur were dissolved in 4.5 ml of CS2, a catalyst was added, and the solvent CS2 was stirred and irradiated with an infrared lamp (50 ° C., 1 hour). The catalyst impregnated with CS-40 and sulfur obtained by removing the catalyst was packed in a reactor, and the pressure was 30 kg /
Presulfurization was carried out in the same manner as in Example 1 in accordance with the temperature program in FIG.

EXAMPLE 3.1 1.20 g of CS-40 was dissolved in 3.0 ml of acetone, a catalyst was added, and the acetone was removed under irradiation with an infrared lamp (50 ° C., 1 hour) with stirring. Except for this, presulfurization was performed in exactly the same manner as in Example 2.

Comparative Example 1.4 In a stream of hydrogen gas containing 30.95% by volume of hydrogen sulfide (gas flow rate: 30 ml / min), FIG.
The catalyst was presulfurized under normal pressure according to the temperature program described in Even if the heating time of Comparative Example 1 was set to 6 hours, there was no great difference in the activity described later from the case of 3 hours.

Embodiment 4 FIG. Using a fixed-bed high-pressure flow reactor, for each of the presulfurized catalysts prepared in Examples 1 and 2 and Comparative Example 1, a hydrogen pressure of 30 kg / cm 2, a reaction temperature of 330 to 390 ° C., a hydrogen flow rate of 2 liter / hour, Sample flow rate 16 ml / h, liquid volume hourly space velocity 4 /
Hydrodesulfurization reaction of Middle Eastern straight-run gas oil was conducted under the condition of time, and in particular, dibenzothiophene (DB
T), 4-methyldibenzothiophene (4-MDB
T) and the conversion of 4,6-dimethyldibenzothiophene (4,6-DMDBT) were measured to evaluate the activity of each presulfurization catalyst.

DBT, 4-MDBT and 4,6-DMD
The conversion rate of each BT is as shown in FIGS. 3 to 5. In each case, the higher the reaction temperature, the higher the conversion rate, and the pre-sulfurization catalyst obtained in Examples 1 and 2 was used. In this case, it is clear that the results are better than those in the case of using the pre-sulfurized catalyst prepared by the conventional method of Comparative Example 1.
In particular, when compared with the conversion of 4,6-DMDBT, the effect of the presulfurization catalyst of the present invention is clearer.

Embodiment 5 FIG. In place of Middle Eastern straight-run gas oil, use Middle Eastern hydrotreated oil to achieve deep desulfurization,
4,6-DMDBT and two TMs contained in the sample
When the conversion of DBT (trimethyldibenzothiophene) was measured, the results of FIGS. 6 and 7 were obtained. These results are similar to those of Example 4, but the difference between the effect of the presulfurization catalyst of the present invention and the effect of the conventional presulfurization catalyst is more remarkable than that of Example 4.

In the case of Example 3 in which only CS-40 was used as a sulfurizing agent, the results were better than those of the conventional method.
And 2 were confirmed to be inferior. In addition, CS-4
0 has little effect on the conversion, so the amount of CS-40 used is at least as high as in Examples 1 and 2.
In the presulfurization conditions described above, a stoichiometric amount of sulfur in the sulfide when the active metal species on the catalyst is completely sulfurized is sufficient. These experimental data are as shown in Tables 1 and 2.

[0031]

[Table 1]

[Table 2]

[Brief description of the drawings]

FIG. 1 is a heating temperature program performed at the time of preliminary sulfurization in Examples 1 to 3.

FIG. 2 is a heating temperature program performed at the time of preliminary sulfurization in Comparative Example 1.

FIG. 3 is a graph showing the conversion of DBT in Example 4.

FIG. 4 is a graph showing the conversion of 4-MDBT in Example 4.

FIG. 5 is a graph showing the conversion of 4,6-DMBT in Example 4.

FIG. 6 is a graph showing the conversion of 4,6-DMBT in Example 5.

FIG. 7 is a graph showing the conversion of TMDBT in Examples.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C10G 45/06 C10G 45/06 B 45/08 45/08 B 45/10 45/10 B

Claims (8)

[Claims] 1. A method for producing a preliminary sulfurization catalyst used in a hydrodesulfurization reaction, comprising heating a catalyst containing a sulfurizing agent in advance in pores on a surface thereof in a hydrogen gas atmosphere to sulfide. A method for producing a pre-sulfurized catalyst, wherein the temperature of the system is gradually increased to a temperature at which hydrogen is generated. 2. The method according to claim 1, wherein the hydrogen gas atmosphere is a pressurized hydrogen gas atmosphere. 3. R-Sn-R '(R and R' are organic groups having a total number of carbon atoms of 1 to 150, and n is 1 as a sulfurizing agent.
It is a number from 10 to 10. 2. The method for producing a presulfurized catalyst according to claim 1, wherein the organic sulfur compound represented by the formula (1) is used. 4. The method for producing a pre-sulfurized catalyst according to claim 1, wherein two or more kinds of sulfide agents having different decomposition temperatures are used in combination as the sulfide agent. 5. The method according to claim 1, wherein the two or more sulfurizing agents having different decomposition temperatures are:
The preliminary sulfide agent according to claim 4, which is a sulfidizing agent composed of at least one first sulfide having a decomposition point of 180 ° C or lower and at least one second sulfide having a decomposition point of more than 180 ° C. A method for producing a sulfurized catalyst. 6. The two or more sulphiding agents having different decomposition temperatures,
R-Sn-R '(R and R' have a total number of carbon atoms of 1 to
150 organic groups and n is a number from 1 to 10. 5. The method for producing a pre-sulfurized catalyst according to claim 4, which is a sulfurizing agent composed of an organic sulfur compound represented by the formula) and elemental sulfur. 7. A catalyst comprising a non-acidic carrier carrying a group VI, VIII or at least one other active metal selected from the group consisting of molybdenum, cobalt, tungsten and nickel. A method for producing a pre-sulfurized catalyst according to any one of claims 1 to 6. 8. The method according to claim 1, wherein the hydrodesulfurization reaction is performed on a liquid containing a polycyclic sulfur compound.