JPH04114746A - Preparation of hydrotreating catalyst for hydrocarbon oil - Google Patents

Abstract

PURPOSE:To obtain a catalyst capable of keeping stable activity over a long period of time by using zeolite having one or more metal atom in its cage and allyl mercaptan or thioglycolic acid being a sulfiding agent. CONSTITUTION:Zeolite containing one or more metal atom of the Group V1a of the Periodic Table in its cage and alumina are kneaded and molded. Subsequently, the molded one is dried to be baked and impregnated with allyl mercaptan or thioglycolic acid in an amount necessary for converting said metal atom to oxide and dried to obtain in a hydrogenating catalyst for hydrocarbon oil. As the alumina source, there are gamma-alumina or alumina hydrate. As a metal of the Group V1a of the Periodic Table, there are molybdenum or tungsten but molybdenum is proper from the aspect of catalytic activity or cost. When molybdenum is introduced into the cage of zeolite to form molybdenum disulfide or a precursor thereof in the cage, the flocculation of molybdenum disulfide during the hydrotreatment of hydrocarbon oil can be prevented and activity stable over a long period of time can be kept.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a catalyst used for hydrotreating hydrocarbon oil and a method for producing the same.

[Conventional technology]

Gamma-alumina as a catalyst for hydrotreating hydrocarbon oil, molybdenum, nickel, etc. as active metals in Periodic Table V
Materials loaded with metals of group Ia or group Ⅰ have been used. This catalyst, for example, is produced by kneading alumina hydric material,
It is obtained by impregnating a carrier obtained by molding and firing with an aqueous solution of an active metal salt, drying, and then firing. The catalyst obtained in this way has an oxidation behavior of the active metal and does not show any activity as it is. For this reason, when using this catalyst, a so-called presulfidation step is carried out in which a hydrocarbon oil containing hydrogen sulfide and hydrogen is passed through the reactor after it has been filled into a reaction tower, and the catalyst is put into actual operation. However, this sulfiding step is actually quite a complicated operation, and there is no guarantee that the entire amount of active metal can be converted into sulfiding kinetics.

Incidentally, the activity of the catalyst decreases with time of use, and the main reason for this is thought to be as follows.

■ Blockage of pores due to precipitation of carbonaceous matter ■ Precipitation t: Poisoning of active sites by carbonaceous matter ■ Decrease in active sites due to agglomeration of metal sulfides In actual operation, a decrease in the activity of the catalyst mentioned above is To maintain the desired activity, it is necessary to increase the reaction temperature over time, but this increases the precipitation of carbonaceous substances.
This shortens the life of the catalyst.

[Problems to be Solved by the Invention] The present invention has been made based on the above-mentioned problems, and aims to provide a catalyst that can simplify the presulfurization step and maintain stable activity over a long period of time. be.

[Means to solve the problem]

Therefore, the present invention has been made to solve the above problems.
On a carrier made of zeolite and alumina,
In a method for producing a hydrotreating catalyst for hydrocarbon oil, which supports a group LA metal and then converts the metal into a sulfide,
Success was achieved by preparing a hydroprocessing catalyst for hydrocarbon oils using a zeolite having one or more of the metal atoms in its cage and using allyl mercaptan or thioglycolic acid as the sulfiding agent.

The method for producing a hydrogenation catalyst for hydrocarbon oil according to the present invention involves kneading zeolite and alumina containing one or more metal atoms of group VIa of the Shoulder Period Table in a cage, molding, and drying. , calcining, impregnating this with allyl mercaptan or thioglycolic acid in an amount necessary to convert the metal into a metal sulfide, and drying. In addition, in producing the catalyst of the present invention, one or more periodic table V
A method may be used in which zeolite containing Group Ia metal atoms is mixed with alumina and allyl mercaptan or thioglyfuric acid in an amount necessary to convert the metal in the zeolite into a sulfide, kneaded, molded, and dried. . However, since the latter method tends to cause a slight decrease in catalyst strength, the former method is more preferred.

In the present invention, γ-alumina, alumina hydrate, etc. can be used as the alumina source.

Further, molybdenum and tungsten are considered as metals in Group Via of the periodic table, but molybdenum is suitable from the viewpoint of catalyst activity, cost, etc. Therefore, in the following description, molybdenum will be used as a representative metal of Group VIa of the periodic table.

[Effect]

First, the catalyst of the present invention will be explained.

Introducing molybdenum into a zeolite cage and forming molybdenum disulfide or its precursor in the cage as in the present invention prevents molybdenum disulfide from agglomerating during hydrocarbon oil hydrogenation treatment, This is to maintain stable activity over a long period of time. In addition, in order to make this layer effective, it is necessary to sulfurize the molybdenum in the cage without subjecting it to thermal history, and for this purpose, it is necessary to use allyl mercaptan or thioglycolic acid as a sulfurizing agent. is necessary. The amount of these sulfiding agents is preferably 1 to 3 times the amount required for molybdenum to form the sulfurized form that is highly active in hydrogenation reactions, namely MoS. This is because if the amount of the sulfurizing agent is less than this, the activity will naturally decrease, and even if it is more than this, no further improvement in activity can be expected, which will only impair economic efficiency.

Conventionally, zeolite has been used as a catalyst due to its shape selectivity or molecular sieve effect due to its unique pore size, or decomposition activity due to solid acid. Used as a partition. The zeolite that meets this purpose may be a synthetic or commercially available zeolite, but it is a zeolite that has at least one cage containing molybdenum disulfide or its precursor, and that holds the molybdenum disulfide or its precursor within the cage. It is desirable that the zeolite has a hydroxyl group, and for example, Na-H-Y type zeolite is preferred.

If molybdenum disulfide aggregates, the catalytic activity decreases, but the extent of this aggregation is determined by the extended X-ray absorption fine structure (hereinafter referred to as EX).
AFS) is measured, the result is Fourier transformed,
Evaluation can be made by determining the coordination number of the nearest molybdenum from the obtained radial distribution function around molybdenum.

The smaller the coordination number, the more dispersed molybdenum disulfide is, indicating that the activity is higher.

The principle of local structure analysis using EXAFS is described in [Bunseki J, 1981.4. It is explained on pages 221-228. Even if the catalyst obtained by the method of the present invention is used for 500 hours, the coordination number of nearest molybdenum determined from the radial distribution function around molybdenum is 0.25 or less, at most 0.3 or less, and 500 A significant difference is observed compared to the catalyst obtained by conventional methods, which increases in usage time by more than 1 hour.

Next, the method for producing the catalyst of the present invention will be explained in detail.

The method of introducing molybdenum into the zeolite cage is not particularly limited, and for example, the method of P. Gallezot et al. using a compound such as Mo(Co) may be used. To prepare a catalyst using the zeolite thus obtained containing at least one molybdenum atom in the cage, the zeolite is mixed with a desired amount of alumina, kneaded, shaped, dried, and calcined. to obtain a catalyst carrier,
There is a method in which this carrier is impregnated with allyl mercaptan or thioglycolic acid in an amount of 1 to 3 times the amount required to convert the MO in the carrier to MoS, and then dried at less than 100°C. In addition, a desired amount of alumina and Mo in the zeolite are added to the zeolite containing one or more molybdenum atoms in the cage.
is mixed with allyl mercaptan or thioglycolic acid in an amount of 1 to 3 times the amount required to make MoS2, and kneaded,
It may be shaped and dried below 100°C. but,
Catalysts obtained by the latter method tend to have lower strength than those obtained by the former method.

In either method, when the amount of zeolite in the carrier decreases, the amount of MO in the catalyst decreases and the activity decreases, so the amount of zeolite must be 10% by weight or more.

On the other hand, if the amount of zeolite is too large, the strength of the carrier will decrease. Therefore, the amount of zeolite needs to be 90% by weight or less. This is because alumina plays a role in maintaining the strength of the molded body.

Furthermore, various mercaptans can be considered as sulfur compounds that can be used as sulfurizing agents, but if the molecules are too large, they cannot penetrate into the zeolite cage, so it is necessary to use allyl mercaptan or thioglycolic acid.

In the method of the present invention, after supporting or mixing the sulfurizing agent, drying is carried out at 100°C or lower, which causes Mo to react with the sulfurizing agent to form an organic molybdenum compound that is a precursor of MoS2. This is to do so.

In the catalyst of the present invention obtained in this manner, molybdenum is an organic molybdenum compound, so oxidation can be prevented before use, and the molybdenum can be easily separated from the organic molybdenum compound during the heating process for treating hydrocarbon oil. Since molybdenum disulfide can be formed, the conventional pre-sulfurization process is not necessary.

Furthermore, since molybdenum disulfide is formed at a relatively low temperature, molybdenum in the cage can be prevented from moving outside the cage and agglomerating during formation.

This will be explained in more detail below using examples.

(Example) 100g of molybdenum carbonyl (molybdenum content 36.4% by weight) was dissolved in 10ff of n-hexane7, and commercially available Na-H-Y type zeolite (manufactured by Tosoh Corporation) 1009 was added to the obtained solution. After stirring at room temperature for 1 hour, the obtained zeolite was dried under reduced pressure at room temperature for 1.5 hours using a commercially available vacuum dryer, then heated under reduced pressure at 50° C. for 1 hour, and then allowed to cool to room temperature. This zeolite I got 100g
and an alumina hydrate of 1009 in terms of oxide,
After extrusion molding and drying at 120°C for 10 hours,
Carrier A was obtained by firing at ℃ for 2 hours. Next, carrier A was impregnated with an aqueous solution containing allyl mercaptan and dried at room temperature to obtain catalyst A. This catalyst A is of the present invention.

Next, 65 g of the same Ha-H-Y type zeolite as above and 100 g of alumina hydrate in terms of oxide were kneaded, extruded, dried at 120°C for 10 hours, and then heated to 500°C.
After baking for 2 hours, a carrier B was obtained. This carrier B1659 was impregnated with 100 mQ of a solution prepared using 52.59 molybdenum trioxide, ammonia, and water, and then heated at 120°C for 10 min.
After drying for an hour, it was calcined at 500°C for 2 hours to obtain catalyst B. This catalyst B corresponds to a conventional product.

Catalyst B was presulfurized under the conditions shown in Table 1, and catalyst A was hydrodesulfurized using Kuwait atmospheric gas oil having the properties shown in Table 2 under the conditions shown in Table 3.

2nd Table Treatment oil is sampled every 8 hours, and 50 hours above 16:00.
The sulfur content of the sample at 0 hours was measured to determine the desulfurization rate. The results are shown in Table 4.

Next, catalyst A and catalyst B before use (immediately after sulfurization) and 500
E of high energy laboratory with them after time use
EXAFS measurements are performed at the XAFS experimental facility, and the obtained absorption coefficients are 7-lier transformed using a computer to calculate M
Find the radial distribution function around o, Mo-5 and Mo-Mo
The average coordination number was calculated.

The results are shown in Table 5.

It can be seen that although almost no agglomeration of Mo occurred in the catalyst and the decrease in activity was suppressed, the aggregation of molybdenum was more severe in catalyst B than in catalyst A, and as a result, the decrease in activity was greater.

〔Effect of the invention〕

In the catalyst of the present invention fabricated by the method of the present invention, MoS is immobilized within the zeolite cage, so it is possible to maintain high activity for a long period of time in the hydrogenation treatment of hydrocarbon oil. , and M.

Since MoS 2 is supported as an organic molybdenum compound which is a precursor of MoS 2 , the conventional pre-sulfurization step is not necessary.

Patent Applicant: Director of the Agency of Industrial Science and Technology, Sugiura, Approved by: Sumitomo Metal Mining Co., Ltd. [Note] - is undetectable From Tables 4 and 5, for catalyst A, representatives of Hydroprocessing Sumitomo Metal Mining Co., Ltd. -j, and 2 other people -

Claims (1)

[Claims] 1) A method for producing a hydrotreating catalyst for hydrocarbon oil, in which a metal of Group VIa of the periodic table is supported on a carrier made of zeolite and alumina, and then the metal is converted into a sulfide, A method for producing a hydrotreating catalyst for hydrocarbon oil, characterized in that the zeolite is a zeolite having one or more metal atoms in its cage, and allyl mercaptan or thioglycolic acid is used as a sulfiding agent. 2) 10 to 90% by weight of zeolite containing one or more molybdenum atoms in the cage and 90 to 10 parts by weight of alumina are kneaded, shaped, dried, and calcined, and then molybdenum is mixed with molybdenum disulfide. 2. The method for producing a catalyst according to claim 1, characterized in that the catalyst is impregnated with allyl mercaptan or thioglycolic acid in an amount of 1 to 3 times the amount required for the catalyst, and dried at less than 100°C. 3) 10 to 90% by weight of zeolite containing one or more molybdenum atoms in the cage, 90 to 10% by weight of alumina, and 1 to 3 times the amount of allyl mercaptan required to convert molybdenum to molybdenum disulfide. 2. The method for producing a catalyst according to claim 1, wherein the catalyst is kneaded with thioglycolic acid, molded, and dried at less than 100°C.