JPH1176823A - Slurry catalyst for cracking heavy hydrocarbons and method for preparing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slurry catalyst which prevents an iron-based compound (catalytically active component) from aggregating and growing during a reaction and has a high activity in a coal liquefaction or a heavy oil hydrocracking reaction and its preparation. Providing a way. A coal and d ₅₀ (50% particle size cumulative distribution on a volume basis of the secondary particles formed by aggregation of primary particles) is 20 to 30
A mixture with an iron compound catalyst having a particle size of 0 μm is co-milled in an oil of 40 to 60% by weight with respect to the total amount of the oil mixed with the oil until the average particle size of the coal becomes 20 μm or less. Can be produced in the form of a slurry catalyst for cracking heavy hydrocarbons, which is adhered in a thin layer on the surface of coal in which oil is finely dispersed in oil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slurry catalyst used for a heavy hydrocarbon cracking reaction such as liquefaction of coal or hydrocracking of heavy oil.

[0002]

2. Description of the Related Art In order to cope with soaring oil prices and depletion of resources in the future, technological development of coal liquefaction and cracking of heavy hydrocarbons such as oil shale, oil sands and residual oil of refineries has been promoted.

[0003] The catalytic action of the metal species in these reactions is to stabilize the free radicals generated by thermal decomposition by rapid hydrogenation and prevent coking by recondensation of the decomposition products.

[0004] For this purpose, the chemical or physical properties of the catalyst are improved, for example, by purifying and atomizing the catalyst component. In addition, the catalyst is finely dispersed by using carbon black, pulverized charcoal, and the like. Various attempts have been made to prevent aggregation.

[0005] It is important to improve the performance of the catalyst in this way, but on the other hand, even if the preparation method is easy, it is difficult to bring about practical use of an expensive catalyst. Generally, a transition metal is often used as a catalyst, and among them, an economical one such as an iron compound catalyst must be used.

[0006] Even when iron oxide or iron hydroxide having a large surface area is chemically prepared and used as an iron compound catalyst, the catalyst becomes pyrotite in the presence of sulfur during a high-temperature liquefaction reaction. Has been shown to be very small.

[0007] Measures aimed at improving the activity of the catalyst, such as the addition of iron to the surface of coal by ion exchange and the deposition of fine iron hydroxide on the surface of coal, have achieved some effects, but are both economical and effective. It can be said that there are no excellent catalysts at present.

[0008] In recent years, along with the progress of fine pulverizers, research has been conducted on fine pulverization of iron ore and mineral pyrite or co-pulverization of these with coal. They attempt to exploit the development of new grinding surface states by co-grinding, but after all, the modification of natural products formed over the years requires excessive grinding power.

That is, the crushing mechanism is different between the catalyst of the mineral substance and the crushing of so-called coal which is a fibrous polymer. The primary particle size at which coal can be easily pulverized is considered to be 7 to 8 microns, and pulverization to a finer particle size involves an exponential increase in pulverization power. When the co-ground catalyst is used, an increase in the yield of the product oil is recognized, but the pulverization cost is high, so that practical use is not achieved.

On the other hand, synthesized iron compounds such as iron sulfate, iron nitrate, iron hydroxide and iron sulfide are small ones.
Consist of agglomerates of secondary particles, which are at a temperature of 400-480
When used under conditions of coal liquefaction or heavy oil hydrocracking at 150 ° C. and a pressure of 150 to 250 atm, it reacts with sulfur added to coal or heavy oil or added as a cocatalyst to form pyrotite (Fe _1-x S). At that time, the agglomeration state is broken and the specific surface area of the catalyst is increased, which is a very preferable property as a catalyst. However, reagglomeration of fine particles is inevitable and results in a chained aggregate of about 5 to 7 microns, which is not always an ideal state for hydrogenation of free radicals.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to prevent an iron-based compound (a main component of catalytic activity) from aggregating and growing during the reaction, and furthermore, it is extremely high in coal liquefaction or heavy oil hydrocracking. It is to provide a slurry catalyst having activity.

[0012]

Means for Solving the Problems The present inventors have conducted research on inexpensively and effectively preventing the coagulation of catalyst species among fine iron compound catalysts using coal or the like. An iron compound consisting of an aggregate of primary particles and a small amount of coal are co-milled in oil, or each is crushed independently, and then both are mixed in oil to be crushed to, for example, 20 microns or less. It was found that the iron compound disintegrated on the surface of the coal particles was able to create a state in which the iron compound was extremely thinly layered and adsorbed. By thinly depositing the catalyst primary particles on the coal surface, the cohesion of iron compounds is suppressed, the fragments generated by heat are more reliably stabilized, and the oil yield is improved at the same addition rate, or The same oil yield can be obtained with less catalyst.

That is, a first aspect of the present invention is a slurry catalyst comprising a pulverized coal having an average particle size of 20 μm or less, a crushed iron compound, and an oil, wherein the weight ratio of the crushed coal to the crushed iron compound is attained. A slurry catalyst for cracking heavy hydrocarbons, characterized in that the amount is 1/3 to 3 and the total amount is 60 to 40% by weight of the whole and is retained in the remaining oil.

A second aspect of the present invention is the above-mentioned catalyst, which is a catalyst for cracking heavy hydrocarbons, in which a crushed iron compound is finely dispersed in oil and adhered in a thin layer on the surface of coal.

According to a third aspect of the present invention, in the first or second catalyst, the disintegrated iron compound comprises primary particles and secondary particles in which the primary particles are aggregated, and the primary particles have a particle size of 10%.
It is a catalyst for cracking heavy hydrocarbons of up to 400 nanometers.

A fourth aspect of the present invention is the catalyst for cracking heavy hydrocarbons according to any one of the first to third catalysts, wherein the iron compound is iron sulfide.

A fifth aspect of the present invention is to provide a mixture of coal and an iron compound catalyst having a d ₅₀ (50% particle size of a volume-based cumulative distribution of secondary particles in which primary particles are aggregated) of 20 to 300 μm with an oil. A method for preparing a slurry catalyst for cracking heavy hydrocarbons, comprising co-milling 40 to 60% by weight of oil with respect to the total amount including the above until the average particle size of the coal becomes 20 μm or less; It is.

A sixth aspect of the present invention is to disperse the iron compound catalyst after mixing coal pulverized to an average particle size of 20 microns or less with an oil containing an iron compound catalyst having a d50 of ₂₀ to 300 microns. A method for preparing a slurry catalyst for cracking heavy hydrocarbons.

Conventionally, it has been considered that when a mineral substance and coal are pulverized strongly, that is, co-pulverized to a submicron level, bonding by a mechanochemical phenomenon occurs on the renewed surface due to pulverization of both.

[0020] However, d ₅₀ is 20 to 300 microns (preferably 50 to 200 microns, more preferably 1
An iron compound consisting of higher order particles of about 0.00 to 150 microns) is mixed in oil with approximately equal volume of coal having an average particle size of, for example, about 50 microns to obtain a total amount of iron compound and coal of 4%.
A slurry of 0 to 60% by weight and mild co-milling, that is, co-milling of coal having an average particle size of 50 microns to about 10 microns, surprisingly shows that It has been found that iron-based compounds can be deposited almost uniformly.

That is, when the cut surface of the co-milled solid particles is observed with a scanning electron microscope, primary particles having a particle size of 10 to 400 nanometers, which constitute an iron compound on the surface of the coal, have a thickness of several microns or less. Attached in layers. In spite of the fact that the surface renewal degree of both types of particles is not so high, both types adhere to each other and exhibit an effective state for suppressing aggregation of the iron-based compound. Then, it was found that when this is used as a coal liquefaction catalyst, for example, the liquefied oil yield is improved by several% as compared with the case where an iron compound is used alone. In the early stage of the liquefaction reaction, the co-ground coal swells, and the iron compound reacts with sulfur to form pyrotite, and finally, the solid coal component turns into a liquid or gas and disappears, so the iron compound deposited on the coal I do not know how long it has been in its original state. But,
The initial stage of this liquefaction reaction greatly affects the oil yield from coal. Therefore, there is no doubt that fine dispersion of the catalyst is extremely important.

In the case of co-milling mineral matter and coal so that the average diameter is 1 micron, only the grinding power of coal alone is sufficient.
Approximately 1,000 KWH per ton of coal is required, which adds to the power of grinding the minerals, which is extremely expensive.

On the other hand, in the co-pulverization of the iron compound catalyst and the coal in the present invention, the pulverization power when the pulverization of the coal is set to about 10 μm is about 10 KWH per ton of coal, while Is easily disintegrated, so that co-milling power is extremely small.

Since it was confirmed that there was no significant difference in the oil yield obtained by liquefaction only by changing the pulverized particle size of the coal, an epoch-making and low-cost catalyst coagulation prevention measure could be realized by such mild co-pulverization. .

In the above-mentioned co-pulverization method, although the disintegration power of the iron compound catalyst is small, the concentration of the slurry of the coal and the iron compound needs to be limited to about 60% by weight at most due to viscosity restrictions. Therefore, when the co-pulverization amount, that is, the total amount of coal, catalyst and oil is large, the required number of co-pulverizers increases. Therefore, the average particle diameter is reduced to 20 μm or less (for example, about 10 μm) by pulverizing only coal in oil or by dry pulverization without using oil, and d ₅₀ is 2
The mixture was mixed with an iron compound catalyst of 0 to 300 microns and crushed in oil using a crusher having a high-speed shearing blade or the like. The results of scanning electron microscope observation of the particles obtained by this method were the same as those obtained by the co-pulverizer, and proved to be a more inexpensive method for preventing catalyst particle aggregation.

In the case of pulverizing coal, if it is possible to obtain fine particles cut from a coal liquefaction or a dust collector of an electric power pulverizer, it is not necessary to provide a dedicated facility. As the above-mentioned iron compound catalyst, preferably, for example, JP-A-9-142849 is used.
As disclosed in US Pat. No. 6,064,086, Fe is obtained by reacting iron sulfate containing ferrous sulfate monohydrate as a main component with a sulfur compound.
D ₅₀ of the secondary particles having a particle size mainly composed of S ₂ are formed from the primary particles of 10 to 400 nanometers 20 to 300
Micron iron sulfide.

[0027]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

In the following Examples and Comparative Examples, the particle size measuring apparatus used in the following Examples and Comparative Examples is a laser diffraction method manufactured by Seishin Enterprise (MS-24), and the scanning electron microscope is manufactured by Hitachi, Ltd. (S-960). Was used.

The term d ₅₀ (average particle diameter) refers to a 50% particle diameter of a volume-based cumulative distribution measured by dispersing a particle size measurement sample in isopropyl alcohol.

[0030]

Examples 1 and 2 and Comparative Example 1 As shown in FIGS. 1 and 2, a synthetic iron sulfide catalyst prepared according to JP-A-9-142849 (iron sulfide and a method for producing the same) (average particle diameter 100 μm) 6.7 kg) and 3.3 kg of Indonesian coal (average particle size: 50 microns) were mixed with 15 kg of oil (normal pressure light oil) obtained by coal liquefaction to form a 40% by weight slurry. Next, this was charged into a continuous rotary ball mill having an inner volume of 30 L (a slurry-filled void volume of 10 L) at a supply rate of 5 L / H, and continuously pulverized. What was taken out from the outlet of the pulverizer was designated as A catalyst. An electron micrograph of this catalyst is shown in FIG. The average particle size was 7 microns.

Next, synthetic iron sulfide (average particle diameter: 100 μm) and coal (average particle diameter: 50 μm) were added to each of 40 parts.
% Of the slurry and pulverized separately under the same conditions as in the co-pulverization. A mixture of the slurry A and the catalyst in the same ratio was used as a catalyst B.

Next, instead of using a crusher, the synthetic iron sulfide was crushed in a tank equipped with high-speed shearing blades (tip speed: 20 m / sec), except that the catalyst obtained in the same manner as the B catalyst was used as the C catalyst. did.

Further, synthetic iron sulfide (average particle diameter 100 microns), coal (average particle diameter 20 microns or less) and atmospheric gas oil are added at the ratio of catalyst A preparation. And crushed. The obtained product was designated as D catalyst.

Using the catalyst prepared as described above,
A coal liquefaction reaction experiment was performed. A 1 L autoclave reactor was used. The reaction conditions are as follows. (1) Coal: Indonesian coal (elemental analysis: C7.6, H
(5.6, N1.4, O16.2, S0.2wt%, ash content 4.8wt%) (2) Medium oil: normal pressure light oil (3) Coal slurry concentration: 40% (4) Catalyst concentration: anhydrous, no 1% as iron weight per ash coal (DAF) (5) Reaction pressure: 170 kg · cm ^-2 (6) Reaction temperature: 450 ° C. (7) Reaction time: 60 minutes As a comparative example, co-milling or single milling is not performed Synthetic iron sulfide was used as the E catalyst. The amount of catalyst used was determined in Examples 1-2.
1% by weight as iron weight on a DAF basis as in Example 1. Table 1 shows the results of evaluation of activity in a 1 L autoclave.

[0035]

[Table 1]

In Table 1, the oil yield is the weight fraction of the hexane-soluble component relative to DAF. The hexane-insoluble fraction is indicated by a weight fraction of the total weight of asphaltenes and pre-asphaltenes with respect to DAF, and is a scale indicating the degree of hydrogenolysis.

[0037]

According to the present invention, the following effects can be obtained. 1. A highly active iron sulfide catalyst adsorbed in a thin layer on the surface of coal particles can be produced. 2. Dramatically improves the activity of the iron sulfide catalyst. 3. As a practical production method, it is only necessary to disintegrate iron sulfide, and coal can use a fine-grain cut portion for other uses, so that production cost is low.

[Brief description of the drawings]

FIG. 1 is a scanning electron micrograph of a catalyst (secondary particles in which primary particles are aggregated) used in the present invention.

FIG. 2 is an enlarged scanning electron microscope photograph of FIG.

FIG. 3 is a scanning electron micrograph of a slurry catalyst prepared according to the present invention.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shigeyoshi Hayashi 2 at Samejima, Fuji City, Shizuoka Prefecture Asahi Kasei Kogyo Co., Ltd. Inside the Industrial Co., Ltd.

Claims (6)

[Claims] 1. A slurry catalyst comprising pulverized coal having an average particle size of 20 μm or less, a crushed iron compound and oil, wherein the weight ratio of the crushed coal to the crushed iron compound is 1/3 to
3. The slurry for cracking heavy hydrocarbons according to 3, wherein the total amount is 60 to 40% by weight of the whole, and the catalyst is dispersed and held in the remaining oil. 2. A slurry catalyst for cracking heavy hydrocarbons according to claim 1, wherein the cracked iron compound is attached in a thin layer on the surface of coal finely dispersed in oil. 3. The crushed iron compound is composed of primary particles and secondary particles in which the primary particles are aggregated, and the primary particles have a particle size of 10%.
2. The method according to claim 1, wherein the thickness is from 400 to 400 nanometers.
Or the slurry catalyst for heavy hydrocarbon cracking according to 2. 4. The slurry catalyst for cracking heavy hydrocarbons according to claim 1, wherein the iron compound is iron sulfide. 5. The coal and d ₅₀ (50% particle diameter of a volume-based cumulative distribution of secondary particles in which primary particles are aggregated) are 20 to 30.
A mixture with an iron compound catalyst having a particle size of 0 micron is co-milled in 40 to 60% by weight of oil with respect to the total amount including the oil until the average particle size of the coal is 20 microns or less. A method for preparing a slurry catalyst for cracking heavy hydrocarbons. 6. An iron compound catalyst in which coal pulverized to an average particle diameter of 20 μm or less has a d ₅₀ (50% particle diameter of a volume-based cumulative distribution of secondary particles in which primary particles are aggregated) of 20 to 300 μm. A method for preparing a slurry catalyst for cracking heavy hydrocarbons, comprising: dispersing the iron compound catalyst after mixing with an oil containing