JPH04210240A - Hydrogenation catalyst and its production - Google Patents

Abstract

PURPOSE:To obtain a highly active hydrogenation catalyst by depositing a catalytic metal on a carrier and dry-sulfurating the metal without calcining it. CONSTITUTION:Catalytic metals such as molybdenum, cobalt and nickel are singly or plurally deposited on a carrier of gamma-alumina, etc. The metals are heated, dehydrated and sulfurated in a reducing atmosphere without being calcined and without the metal salts depositing on the catalyst surface being converted to their oxides to obtain different surface structures. Heavy hydrocarbons are hydrogenated and efficiently reformed or cracked by the catalyst thus obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a hydrotreating catalyst used when hydrogenating a heavy hydrocarbon as a raw material to obtain a lighter fraction. .

[Prior Art] In recent years, with energy problems and the depletion of fossil fuels, research on hydrorefining reactions using hydrocarbons such as heavy and medium oils as raw materials has been actively conducted.

Especially vacuum residual oil, oil shale, and oil sands.

Regarding the efficient lightening of heavy oil containing many aromatic rings obtained from coal, etc., there is a strong desire for the development of new technology from the perspective of expanding the uses of new fuel oil.

In addition, in order to create a better environment, there is a need for even cleaner fuels as well as exhaust gas treatment technology, necessitating the development of new high-performance catalysts.

Catalysts used in the hydrogenation reaction of heavy hydrocarbons include molybdenum, tungsten, cobalt, nickel, iron, etc., prepared from inorganic salts, singly or in combination with alumina.

It has been used as a catalyst by being supported on a carrier such as titania or silica. These catalysts are prepared by supporting an active metal on a carrier, drying it, and then calcining it in air at a temperature of 400 to 600°C. The prepared oxide catalyst is sulfurized prior to the reaction and used as a sulfide catalyst in the hydrogenation reaction.

[Problems to be Solved by the Invention] However, in the catalyst calcined at a temperature of 400 to 600°C, active metals such as cobalt, nickel, molybdenum, tungsten, and iron are largely dispersed during the drying, calcining, and sulfurizing processes. Change.

There is also the problem that the active metal forms a composite oxide with the carrier component. For this reason, the required reaction selectivity.

It has high activity and hydrogenation activity.

The development of new catalyst systems that can control the basic functions of catalysts, such as hydrocracking activity, is expected.

Therefore, an object of the present invention is to provide a method for preparing a catalyst that can be used to efficiently reform or lighten heavy hydrocarbons by hydrotreating them. That is, the catalyst is prepared by drying and calcining the catalyst in an air atmosphere, passing through an oxide catalyst, and then converting it into a sulfide catalyst by sulfurization, without going through the process of preparing the catalyst, and directly converting it into a sulfide catalyst after drying. shall be.

Specifically, after impregnating and supporting the active metal species, dry sulfurization is performed without calcination to form a sulfide catalyst.

According to this method, the dispersion state of the active metal on the catalyst surface can be controlled, the carrier and the active metal species do not form a composite oxide and the active metal species are effectively dispersed on the catalyst surface, and the active metal species can be easily activated. There are many advantages that can be considered for improving the performance of catalysts, such as sulfurization of metal species. Therefore, we can expect the development of new catalysts that differ from conventional catalyst functions.

In other words, by heating and dehydrating and sulfurizing the metal salts supported on the catalyst surface in a reducing atmosphere without converting them into oxides, we can create catalysts with a surface structure different from conventional catalysts and exhibiting new functions. We can expect development.

[Means for Solving Problem W] As a result of various studies to solve the above problem, the present inventors have found that nickel, cobalt, molybdenum, tungsten, and iron are It was found that the dispersion state or oxidation-reduction state of metals such as metals changes, and as a result, the desired catalytic activity cannot be obtained and the reaction selectivity decreases. Therefore, we conducted research to solve these problems, and in the process discovered that the dry preparation method of the present invention is superior, leading to the present invention.

In other words, the catalyst of the present invention has much higher hydrocracking activity than conventional catalysts. In order to improve the hydrogenolysis activity, it is necessary that the atoms of molybdenum, tungsten, etc. are aggregated to some extent.2 The catalyst of the present invention has a clearly different aggregated form of molybdenum compared to conventional catalysts. EXAFS shows that molybdenum contributes to improving hydrogenolysis activity when dry preparation method at low temperature is used.
(X-ray absorption edge fine structure) measurement results.

[Example] Hereinafter, the present invention will be explained in more detail based on Examples.

Example 1 Preparation of catalyst The catalyst carrier was γ-alumina (diameter: 1/32 inch).

Columnar shape, pore size 80 people 2 surface area 240m+”/g
) was selected and used. Catalysts using molybdenum, cobalt, nickel, tungsten, or a combination of these as active metals were prepared under different preparation conditions. An example of the composition of various catalysts is 21.7% MoO, /A Q 203.3
．． 5tit%Ni0-15.0st%Mob, /A
Q20. , 3.5wt%Coo/A Q 203
, and 1, 75wt%Ni0-1.75wt%Co
o-15wt% Mob.

/AQ20. (The number of active metal atoms was the same among the various catalysts.)

The specific catalyst preparation method is to first mix ammonium molybdate, nickel nitrate, and cobalt nitrate with aqueous ammonia (2
8%), and the solution concentration was adjusted to have the above composition. Then, γ-alumina is soaked in the solution (impregnation method)
A catalyst having the above composition was prepared. The obtained impregnated molded products were dried and fired in four ways. Method A is for 12 hours in the atmosphere.
In Method B, each sample was dried at 110°C for 2 hours. Methods C and D were dried at 110°C for 2 hours and then fired at 300°C (method C) and 550°C (method D) for 1 hour.

Example 2 Evaluation of Catalytic Activity The prepared catalyst was subjected to a sulfiding treatment at 400°C for 1 hour using a hydrogen sulfide-containing gas of 5v01% H2S/)I2, and was used in various hydrogenation reactions. The activity was evaluated using model compounds in terms of hydrogenation (HY) activity and hydrogenolysis (HC) activity. The model compound used was 1-methylnaphthalene (1-MN).

The yield of 1,5-methyltetralin was defined as HY activity. Further, using diphenylmethane (DPM), the yield of benzene and toluene was determined as HC activity. The reaction was carried out using an autoclave (inner volume 50 cm3) with 0 catalyst.
．． 3g, model compound 10011, hydrogen initial pressure 70k
g/c, m2. Reaction temperature: 310°C (HY activity), 40
0°C (HC activity) 2 reaction time 1 hour.

Capillary gas chromatography was used to analyze the reaction products.

Method A (drying in the atmosphere for 12 hours) Method B (drying at 110°C for 2 hours) Method D (drying at 110°C for 2 hours.

Baking at 300℃ for 1 hour) Method D (drying at 100°C for 2 hours.

550°C for 1 hour) As a result, it was found that the catalyst that was dry sulfurized without undergoing a calcination process exhibited higher hydrocracking activity than the catalyst that was sulfurized after calcination. Also.

Similar results were obtained using catalysts with different combinations of active metal species and different supported amounts.

Example 3 The coordination number of Mo-5, ie, S around MO, was measured by EXAFS. Theoretically, if MO is completely sulfurized.

Six S atoms are coordinated around the Mo atom. Therefore, A,
It can be seen that the sulfurization of the catalyst is progressing in Method B because this value is larger than that in Methods C and D. Also, for Mo-Mo, M around Mo atoms.

The theoretical value is 6. It can be seen that the aggregation form of MoS2 differs depending on the difference in this value. From the results in the table, it can be seen that the catalyst grew moderately in comparison to the catalyst in which MoS2 crystals underwent a calcination process, and as a result, the hydrogenolysis activity was improved.

As a result of the above, 2. In the catalyst preparation method using dry sulfurization treatment at low temperature according to the present invention, sulfurization of No proceeds easily.

On the other hand, high hydrogenolysis activity was obtained because crystallization was suppressed.

Claims (2)

[Claims] (1) Molybdenum, tungsten as catalytically active metals,
A method in which cobalt, nickel, iron, etc., singly or in combination, are supported on a carrier, and then dry sulfurized without going through a calcination process and used as a hydrogenation catalyst. (2) A method for producing a catalyst, a hydrotreating catalyst, and a method for producing the same, according to claim 1.