JPS61268357A - Method for preparing catalyst for liquefying coal - Google Patents

Abstract

PURPOSE:To inexpensively prepare a catalyst for liquefying coal enhanced in activity, by drying an iron salt powder containing crystal water and/or adhered water and baking the dried one at 200-800 deg.C to form the catalyst for liquefying coal. CONSTITUTION:After an iron salt powder containing crystal water and/or adhered water was dried, the dried one is baked at 200-800 deg.C under a reductive atmosphere to prepare a catalyst for liquefying coal. As the iron salt powder, there is a salt consisting of divalent or trivalent iron and an acid and, concretely, there are inorg. iron salts such as ferrous chloride, ferric chloride, ferrous sulfate, ferric sulfate, ferrous nitrate or ferric nitrate. In order to effectively advance fine pulverization in a degree equal to or more than the thermal decomposition of the iron salt and to enhance coal liquefying effect, sulfur and/or hydrogen sulfide gas sufficient to sulfide iron at the time of baking are allowed to coexist. As a baking reaction apparatus, there is a fluidized furnace or tunnel kiln.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for producing a catalyst for use in coal liquefaction, in which coal is hydrogenated to produce a liquid product.

(Prior Art) A method for obtaining liquefaction (af) containing gas and solids by pulverizing and heating coal and adding hydrogen if necessary has been studied for many years, and many techniques are known. In recent years, due to problems such as fuel oil resources and the diversification of chemical products, the development of coal liquefaction technology has been very active, and many new technologies are being developed.

However, there are still many problems in order to efficiently obtain high-quality fuel oil, ganlin, or chemical feedstock oil. For example, the addition of expensive or environmentally undesirable catalysts was required, the amount of hydrogen required to liquefy the coal was high, and the formation of char during the reaction.

Among them, the reaction conditions in the coal reactor, especially the selection of the catalyst, are one of the important factors that determine the quality of liquefied oil. For this reason, a wide variety of catalysts with different chemical species and physical shapes, including methods of addition, have been developed.

There are a large number of catalysts for coal liquefaction that have been known in the past, but typical chlorides include zinc chloride, tin chloride, aluminum chloride, nickel chloride, iron chloride, etc., and sulfides include tin sulfide, molybdenum sulfide, and sulfide. Lead, copper sulfide, zinc sulfide, nickel sulfide, iron sulfide, etc., oxides such as nickel oxide, silica, alumina, iron oxide, cobalt oxide, titanium oxide, etc., as well as mixtures thereof, red mud, ore, etc. The use of is known.

The above catalyst groups can be roughly divided into three groups.

The first group is chloride-based, which exhibits excellent catalytic effects in coal liquefaction reactions. Among them, in the molten salt method used at high concentrations,
It has been reported that it produces a lot of quality oil, produces a small amount of gas, and shows good liquefaction results. However, in putting illegal methods into practical use, there are major restrictions on the material of the equipment due to the coexistence of hydrogen chloride gas.

The second group is Co, which is often used for heavy oil hydrogenation.

It is a group of expensive metals such as Mo and Ni%W. Although these catalysts have high hydrogenation activity, they have the drawbacks of being susceptible to poisoning and having a short catalyst life. In addition, since the catalyst is expensive, there are methods to keep the catalyst within the reactor, such as in the boiling bed of the H-Coal method, or methods to use the catalyst at a very low concentration and reuse and circulate most of it, as in the DoW method. Processes etc. have been proposed. However, the b deviation has not yet reached the stage of completion.

The third group is iron compounds. It is inexpensive and often used as a disposable catalyst.There are many types of iron compounds used, among which iron hydroxide, red mud, iron ore, iron sulfate, etc. are representative. The activity of these iron compounds increases dramatically when sulfur coexists. Therefore, it has been proposed to add sulfur to coal that has a low sulfur content.

In addition, the catalytic activity of natural pyrite (FeS;
-58645).

(Problems to be Solved by the Invention) Most iron compound catalysts are used with a size of several tens of microns or more, but the coal liquefaction activity in that case is not very good. When this is used after being finely pulverized and classified to a size of several microns or less, the activity increases dramatically. However, mechanically pulverizing and classifying to a size of several microns or less requires high equipment cost and poor yield.
Economically disadvantageous. Although the above-mentioned synthetic pyrite catalyst (Japanese Patent Application No. 58-58645) can be used to directly synthesize fine particle catalysts, the manufacturing cost is still somewhat high.

(Means to Solve the Problems) In order to solve the above five problems, the inventors of the present invention have carried out intensive research and have found that complex methods such as synthesis of fine particles of iron compounds or fine pulverization of natural iron compounds have been developed. After drying iron salt powder containing crystal water and/or attached water without any treatment,
It was discovered that an inexpensive and highly active catalyst could be produced by firing at 200 to 800C, and the present invention was completed.

That is, the present invention is a method for producing a catalyst for coal liquefaction, which is characterized in that iron salt powder containing crystal water and/or adhering water is dried and then calcined at 200 to 800C.

Furthermore, the above-mentioned method is one in which the calcination is carried out in a reducing atmosphere, and the above-mentioned method is in which sulfur and/or hydrogen sulfide gas is allowed to coexist during the calcination to react with the iron salt.

The method of the present invention will be explained in detail below.

In the present invention, iron salt powder means a salt consisting of divalent or trivalent iron and an acid, including ferrous chloride, ferric chloride, ferrous sulfate, ferric sulfate, and ferrous nitrate. Examples include iron, inorganic iron salts such as ferric nitrate, and organic iron salts such as ferrous acetate, ferric acetate, ferrous oxalate, and ferric oxalate.

Crystal water refers to water that is contained in a crystal at a certain compounding ratio and is necessary to stabilize the crystal lattice. Adhering water refers to water other than crystal water that simply physically adheres to the powder. refers to the water that exists. Crystal water dehydrates in stages at a certain temperature, so
If heat transfer is poor during diffusion, water will locally condense, and after the powder is once dissolved, it will re-precipitate, and at this time crystals will grow, which will impede firing. Furthermore, if there is a large amount of attached water, fluidity will be poor and uniform firing will be difficult.

Therefore, in order to obtain an excellent catalyst, a drying step for the purpose of removing crystallization water or adhering water is very important. However, it is not necessary to completely remove all the crystal water and/or adhering water in this drying process, and there is no problem even if some crystal water and/or adhering water remains.For example, in the case of iron sulfate, About 1-3 hydrate salt is sufficient.

The drying temperature must be high enough to remove this adhered water or water of crystallization. If necessary, drying may be carried out in several stages. As for the drying device, it is possible to use any known type of drying device. . For example, reducing the particle size of the powder to about 200 μm or less often has a favorable effect on the operation of the next firing step.

If the firing temperature is less than 200C, the reaction will not proceed sufficiently;
If the temperature exceeds ooC, sintering progresses, the surface area of the powder decreases, and the catalytic activity decreases, so a temperature of 2ooC or more and 800C or less is preferable. During this firing, the thermal decomposition reaction of the iron salt progresses, the powder becomes further finely divided, and the coal liquefaction activity increases. Also, Fe50. Type is Fe, 0. compared to
Since the coal liquefaction activity tends to be high, it is more preferable to perform the firing under reducing atmosphere conditions to produce a powder mainly composed of fine particles of Fe and O. In order to create a reducing atmosphere, a known technique such as firing in the coexistence of coke or sulfur can be employed.

In addition to the sulfur and coke required to react with the iron salt, it is also necessary to add sulfur, coke, etc. in an amount necessary to consume oxygen in the atmosphere. The amount of reducing substance added at this time can be determined to some extent by calculation, but
In reality, it is impossible to completely grasp the amount of oxygen leaking into the reaction system, and the amount of reducing material added is 100q6.
Since it is not guaranteed that it will be completely consumed in the reaction, the final decision must be made experimentally.

In order to advance the atomization beyond the thermal decomposition of iron salts and increase the coal liquefaction activity, it is more effective to coexist with sufficient sulfur and/or hydrogen sulfide gas to sulfidize the iron during calcination. be. As iron sulfides, it becomes finer.

Moreover, when the composition becomes FeS, the coal liquefaction activity increases more.

The calcination reactor may be any type of known furnace, such as a fluidized bed furnace, tunnel furnace, or rotary kiln.

The drying process and the firing process may be performed continuously or in batches using separate equipment, or the drying process and the firing process may be performed alternately in one batch using the same equipment. I don't mind.

The catalyst prepared in the present invention has a secondary particle size of 5 μm or less. If produced under particularly preferable conditions, 1
It is possible to easily produce particles smaller than μ.

The present invention liquefies coal using the catalyst prepared by the method described above, and the method for liquefying coal will be explained in more detail below.

Coal as used in the present invention refers to anthracite coal, bituminous coal, subalcohol, charcoal, peat, and the like. The coal used in the present invention includes:
Bituminous coal, subbituminous coal, and charcoal are more preferred.

Coal is heated at 650-800C.

91 If the temperature is low, the liquefaction rate is slow, and if the temperature is high, carbide and gas increase. 400-500C is most preferred.

In the present invention, it is also possible to liquefy without using hydrogen, for example, using a pre-hydrogenated catalyst.
Depending on the conditions, the liquefaction rate may not improve. Therefore, it is common to carry out a sub-liquid reaction in the presence of hydrogen, and in this case it is desirable to use the highest possible purity.

Further, the pressure when hydrogen is diffused is preferably 10)9/cIIt or more, and optimally 100 to 500 kg/m.

The hydrogen reaction is complex, and an appropriate pressure is selected depending on the structure of the coal, the slurry solvent to be mixed, etc.

In the present invention, liquefaction refers to turning most of the coal into a liquid whose boiling point is above room temperature (approximately 20C) and below 900C in terms of normal pressure, but some high-boiling point compounds, wax-like substances, and paste-like substances are May be included. Therefore, in the present invention, the produced crude oil refers to a mixture containing these substances.

In coal liquefaction using the catalyst of the present invention, operation is carried out by adding hydrocarbon oil as a catalyst to coal in a weight ratio of 50 φ or more, preferably 100 to 400%.

The hydrocarbon oil used here refers to liquefied coal oil or hydrogenated liquefied oil, and contains aromatic hydrocarbons, aliphatic hydrocarbons, acidic oils, basic oils, sulfur compounds, etc. Ru.

Mixed oils containing these oils such as creosote oil and anthracene oil, petroleum fractions, and the like can also be used. The boiling point of the hydrocarbon oil is preferably in the range from 150C to 600C under normal pressure.

Among the catalysts produced according to the present invention, those that do not contain sulfur or those that contain only a small amount of sulfur have an overall S/
It is preferable to add sulfur so that the atomic ratio of Fe is 1 to 2. Of course, this is not the case when raw coal contains a large amount of sulfur.

(Effect of the invention) The effects of the present invention are summarized below.

(1) Very fine, highly active catalysts can be produced stably and easily.

(2) The process is simple.

(3) Raw materials and intermediate materials are easy to handle.

(There is no need to process in an inert gas atmosphere, etc.) (4)
No special step to separate by-products is required.

(5) From the above facts, the equipment cost and raw material proportionate bone etc. are inexpensive, and it is economically very advantageous.

(Examples) Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1 Ferrous chloride tetrahydrate 602 was dried under reduced pressure at 110C, plated on a quartz plate, inserted into a quartz tube set in a horizontal electric furnace, and air was circulated at 15 t/H. While, 6007
:: Baked for 6 hours. The powder taken out after cooling was red in color and was identified as Fe, 03 as a result of X-ray diffraction analysis. This is designated as catalyst A.

Example 2 Ferrous sulfate heptahydrate 60? and 20.7 f of sulfur powder were mixed, placed in a quartz dish, inserted into a quartz tube set in a horizontal electric furnace, and dried at 110C for 1 hour while flowing nitrogen gas at 11t/h. After that, it was fired at 450C for 2 hours. The powder taken out after cooling was black in color, and as a result of X-ray diffraction analysis, the main components were Fe and Q. Although sulfur is stoichiometrically excessive, it is thought that the excess sulfur actually leaked out of the system during temperature rise. This is designated as catalyst B.

Comparative Example Ferrous sulfate heptahydrate 609 and sulfur powder 20.71 were mixed, placed in a quartz tube dish, heated at once while nitrogen gas was flowing at 11 t/h, and fired at 450C for 2 hours.

The powder that was discharged after cooling had lumps in some places. These were easily loosened by hand. Unreacted iron sulfate remained in the center of this lump. As a result of X-ray diffraction of the product, it was found to be a mixture of % FeaO4, FeSO4 and Fe51. This is designated as catalyst D. Figure 2 shows the particle size distribution of catalyst B and catalyst D. It can be seen that catalyst B, which has undergone the drying process, has finer particles and a sharper distribution.

-16-Example 3 The hot air inlet temperature of a fluidized fluidized dryer with an effective area of 0.3 TIt was 250 c, and the wind speed was 1. Om/S, layer height was set to iso fin, and industrial iron sulfate was introduced at a rate of 20 kg/H for drying. The total volume of the vibrating rod mill that supplied this dry powder to the vibrating rod mill was 30t2, and the charging rod was 1
56 pieces of 3φ, frequency 11000cp, total amplitude 91
m11. Processing was performed at a raw material supply rate of 2 kg/mm. The average particle size of the obtained product was 18μ. In this way, sulfur powder was added to the powder obtained by [-] in an atomic ratio of S/Fe
= 6.

Air was blown into a fluidized furnace having a diameter of 30c1r1, and the mixed raw materials described above were fed into the furnace at a rate of 9/H, and the bed temperature was maintained at 400C. The linear velocity of air is 1 at the same temperature
The speed was set at 8 cm/s. The product was collected using a cyclone, further cooled to below 100C, and taken out. Oxygen in the air flowing into the reaction cylinder reacts quickly with sulfur in the raw material, and the inside of the cylinder is maintained at a low oxygen concentration.

The product taken out had a dark greenish-black color, and X-ray diffraction analysis revealed that it was a clean Fed throughout. The average particle size of the primary particles of the product was 0.4μ. The reason why these particles can be collected by a cyclone is thought to be because these particles are agglomerated. This is designated as C catalyst.

Experimental Example Coal liquefaction reactions with three types of catalysts of the present invention and one type of control were carried out using a stirred autoclave having an internal volume of 1 ton. The reaction conditions are shown below.

(1) Coal: Horonai coal 601 as anhydrous ash-free coal (2) Solvent: Decrystallized anthracene oil 120 tons (3) Catalyst concentration: 2% by weight of iron per anhydrous ash-free coal (4) Hydrogen charging pressure: 80
kg/cm (5) Reaction temperature: 460C (6) Reaction time: 1 hour (For three types of catalysts: A, B, and D, powdered sulfur was added in an amount equal to the amount of iron contained in the catalyst. The results of this experiment are shown in the figure.Three types, A, B, and C,
These are the above three types of catalysts of the present invention. For comparison, E shows experimental results for the mineral pyrite.

D is a catalyst example (comparative example) made without a drying process.

The horizontal axis in FIG. 1 is the weight fraction of the hexane soluble fraction extracted with respect to the total oil, which can be considered as a measure of the degree of hydrogenation. Here, the total oil refers to the total weight of the hexane soluble fraction extracted, asphaltenes, and pre-asphaltenes. The vertical axis indicates the weight fraction of the light oil produced relative to the charged anhydrous ash-free coal, which is considered as a measure of the degree of hydrocracking. The term "light oil" as used herein refers to a substance having 5 or more carbon atoms, such as hexane, and having a boiling point of 5 ooc or less at normal pressure. In this figure, when liquefaction progresses toward lightening, the upper right becomes a square,
As a result, it can be used as a measure of catalytic activity.

It is clear from FIG. 1 that the catalyst according to the invention is highly active.

[Brief explanation of drawings]

Figure 1 is a graph comparing the performance of the catalyst according to the present invention and other catalysts, and Figure 2 is a graph comparing the particle size distribution of catalyst B according to the present invention and other catalysts. Smooth crab/km (moth) Bud 21η Melting diameter (/L) Procedural amendment January 14, 1985

Claims (3)

[Claims] (1) A method for producing a catalyst for coal liquefaction, which comprises drying iron salt powder containing water of crystallization and/or adhering water, and then calcining it at 200 to 800°C. (2) A method for producing a catalyst for coal liquefaction according to claim 1, wherein the calcination is performed in a reducing atmosphere. (3) A method for producing a catalyst for coal liquefaction according to claim 1, in which sulfur and/or hydrogen sulfide gas is allowed to coexist during calcination to react with iron salt.