JP2855182B2 - Liquefaction method of coal using impregnated iron catalyst. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for liquefying coal by a supported method using a supported iron-based catalyst (impregnated iron catalyst) supported on coal. More specifically, in the present invention, the coal itself was directly impregnated with ferric sulfate, neutralized with ammonia by urea decomposition in an aqueous solution to form a fine powder type sulfate-type iron catalyst, and supported on the coal. The present invention relates to a method for liquefying coal, characterized in that the efficiency of coal liquefaction is improved by using a coal liquefaction reaction using a supported iron-based catalyst.

[0002]

2. Description of the Related Art In general, coal liquefaction
) Are roughly classified into direct liquefaction and indirect liquefaction.
The former direct liquefaction method is a method in which coal is pulverized, mixed with a solvent such as coal liquefied oil to form a slurry, heated in the presence of high-pressure hydrogen, and decomposed to convert the coal into a liquid fuel.
In the latter method, coal is first gasified to convert it into a mixture of hydrogen and carbon monoxide, and this mixed gas is passed over a catalyst to produce a liquid fuel. Various techniques for improving the reaction conditions and the like have been developed.

[0003] By the way, iron-
There are many examples of research on sulfur-based catalysts, such as research on active species and research on modifying them to increase their activity. But,
Based on the results of these studies, the practical use of coal liquefaction is far from far, and further active research is expected in the future.

[0004] The present inventors have considered that the most important research subject in the coal liquefaction reaction lies in catalyst development, and have systematically examined the activity of conventionally used iron-sulfur catalysts. The purpose of the coal liquefaction reaction is to decompose the large and complicated molecular structure of coal by adding hydrogen thereto, and to efficiently produce many compounds having a small molecular weight with a catalyst amount as small as possible.

The inventors of the present invention have conducted studies on the premise that what is needed for this purpose is to highly disperse the catalyst and increase the contact efficiency between the catalyst and coal, and as a result, the present invention has been achieved.

Although the hydrogenation activity of iron-based catalysts is known to be very mild, it is inexpensive,
Also, due to the advantage of being available in large quantities anywhere, even today, research on coal liquefaction catalysts is often an iron-based catalyst worldwide. The iron-based catalyst used for coal liquefaction is red mud, iron ore, iron oxide, or the like, and is usually used by adding sulfur as a co-catalyst. On the other hand, instead of using iron oxide and sulfur separately, iron sulfide in coal ash and natural iron sulfide or synthetic iron sulfide may be used as a catalyst. These facts suggest that the catalyst species effective for the coal liquefaction reaction is an iron sulfide compound.

[0007]

On the other hand, the present inventors have clarified that a sulfate type iron-based catalyst exhibits higher activity than these iron sulfide-based catalysts [Reference: Otanigawa] Tsuyoshi, "Coal liquefaction reaction with iron-based catalyst", Journal of Fuel Association,
70, No. 5, p. 431 (1991), T. Kotanigawa,
S. Yokoyama, M. Yamamoto and Y. Maekawa, "Cataly
tic activities of sulfate and sulfide in S-promote
d iron oxide catalyst ”, Fuel, vol. 68 (5), 6
18 (1989)]. That is, by adding excess urea to the aqueous ferric sulfate solution and heating it at a predetermined temperature, ferric sulfate is neutralized by ammonia generated from the hydrolyzed urea, and a sulfuric acid type fine iron catalyst can be prepared. .

[0008] In this situation, the present invention
As a result of a series of studies on the coal liquefaction reaction using the above-mentioned sulfuric acid type fine iron-based catalyst, it was completed. The coal itself was directly impregnated with ferric sulfate, and this was decomposed with urea in an aqueous solution. And neutralize with ammonia to generate a fine powder type sulfuric acid type iron catalyst to improve the efficiency of coal liquefaction.

[0009]

That is, the present invention provides a coal liquefaction method characterized by using a coal liquefaction reaction using a supported iron catalyst supported on coal using a urea decomposition method. Things.

[0010] The present invention also provides a method for liquefying the above-mentioned coal, wherein the supported iron-based catalyst is a sulfuric acid type iron catalyst.

Further, the present invention relates to a supported iron-based catalyst comprising impregnating coal with ferric sulfate, neutralizing the impregnated ammonia with urea decomposition ammonia in an aqueous solution to form a sulfated iron catalyst, and supporting the catalyst on coal. It is another object of the present invention to provide a method for liquefying the above-mentioned coal which is a supported iron-based catalyst.

Next, the present invention will be described in more detail. In the present invention, the coal used as a raw material may be any ordinary coal, and any type of coal including oil shale, oil sand or the like can be used. The raw material coal is finely pulverized to an appropriate particle size, and in this case, finely pulverized to 100 mesh or less is preferably used. Ferric sulfate is used as a catalyst to be supported on coal.

Next, in order to carry out a liquefaction reaction by supporting a catalyst on the above-mentioned coal, for example, coal pulverized to 100 mesh or less is added to an aqueous solution in which a predetermined amount of ferric sulfate and urea are dissolved. After thoroughly stirring the mixture and impregnating the coal with the ferric sulfate, the mixture is heated at a reaction temperature of 96 ° C. to 98 ° C. in a reaction chamber to decompose urea in an aqueous solution, thereby reducing ammonia. And the second sulfuric acid
A sulfuric acid-type iron catalyst is generated by neutralizing iron, and a sulfuric acid-type catalyst (impregnated-type iron catalyst) supported on the coal is used to carry out a coal liquefaction reaction according to a normal method and conditions. . In this case, an autoclave is preferably used as the reactor.

As the solvent used in the reaction system, for example, a circulating solvent such as tetralin or coal liquefied oil is used. The reaction system is filled with hydrogen gas, and the pressure condition is set to 100 to 300 atm. can do. further,
As a cocatalyst, various sulfur compounds such as elemental sulfur, hydrogen sulfide, and carbon disulfide can be appropriately added. The reaction time is preferably about 0 to 60 minutes after reaching the reaction temperature, but the reaction time may be appropriately set in relation to the rate of temperature rise, the reaction temperature, and the like, and is not limited thereto. Not something.

By using the coal liquefaction reaction using the supported iron catalyst of the present invention, for example, as shown in the examples described below, 90 wt% of Pacific coal, which has conventionally been difficult with Pacific coal, can be easily obtained. Thus, it is possible to achieve a very high coal conversion, which is higher than that of the conventional method.

Also, conventionally, it has been indispensable to add sulfur as a co-catalyst in the coal liquefaction reaction. However, according to the present invention, without adding the co-catalyst, a higher coal than the conventional method is required. Conversion can be achieved,
Even at a reaction temperature of about 425 ° C, it is possible to obtain a coal conversion rate equivalent to that of the conventional method, and it is possible to activate the catalyst and reduce the amount of catalyst to be added, and to carry out the coal liquefaction reaction with high efficiency. Is possible.

The reaction products of the coal liquefaction according to the present invention are an oil component and an asphaltene component, and the feature thereof is a lightened component.

Hereinafter, the present invention will be described in detail with reference to examples. 1. Experimental Apparatus and Experimental Method A stainless steel autoclave having an inner volume of 70 ml was used as an experimental apparatus, and a predetermined amount of coal, a solvent, a catalyst, and a gas were charged into the autoclave.
The temperature is raised to 50 ° C. at a rate of 2.5 ° C./min. As soon as the reaction temperature is reached, the autoclave is removed from the electric furnace and quenched with a fan to stop the reaction.

In a normal autoclave experiment, when the temperature reaches the reaction temperature, the temperature is maintained for a certain period of time to obtain the reaction time. However, even if the reaction temperature is low, the activity increases if the reaction time is sufficiently long. Therefore, in this example, no reaction time was intentionally taken in order to clearly distinguish the catalytic activities.

2. Reaction conditions Coal was vacuum-dried Pacific coal (carbon; 76.6, hydrogen;
6.2, nitrogen; 1.2, sulfur; 0.1, oxygen;
9, weight%) to 100 mesh or less and 3
g used. Pacific coal was used because it has a very low sulfur content so that the effect of adding sulfur, which is called a promoter, can be clearly understood. The solvent was reagent reagent tetralin, and 10 g was used in each experiment. Hydrogen gas has an initial pressure of 10
The autoclave was filled with MPa. The catalyst impregnation amount is 0.
The value was varied between 1% and 20%, and the amount of catalyst carried was determined from the increase in ash content in the coal. For comparison, 0.5 g of a sulfate-type iron catalyst prepared according to the method of the reference was added to each experiment, and the results were compared with the supported method.

3. Analytical Method After completion of the reaction, the contents of the autoclave were extracted with benzene using a Soxhlet extractor, and the conversion of coal (% by weight) was determined based on the benzene-insoluble matter.

[0022]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the examples. Example 1 (Catalyst impregnation amount and actual supported amount) 30 g (daf base) of Pacific coal finely pulverized to 100 mesh or less was taken, and this was ferric sulfate and urea in an amount 2.5 times that of ferric sulfate. Is added to the aqueous solution in which is dissolved, and the mixture is sufficiently stirred. When the mixture is placed on a water bath and heated at 96-98 ° C for about 2 hours, the added urea decomposes and evolves ammonia to neutralize ferric sulfate. Immediately after the completion of the decomposition reaction, filtration and washing with water are performed, followed by vacuum heating at 120 ° C. to prepare a catalyst-supported Pacific coal. Catalyst impregnation amount (0, 0.1, 1, 5, 10, 2
TU-0, TU-0.1, TU-
1, TU-5, TU-10, and TU-20.
In the present example, the actual amount of loading was determined from the increase in the ash content of each sample.

[0023]

[Table 1] ──────────────────────── No. Actual catalyst loading (wt%) ──────────────────────── TU-00 TU-0.1 0.2 TU-10 6 TU-5 1.8 TU-10 5.9 TU-20 13.2

Example 2 (Comparison of activity between catalyst-supporting method and mixing method) The present inventors have studied the activity and mechanism of a sulfate-type iron catalyst formed by decomposing ferric sulfate with urea. The present invention aims to improve the efficiency of the process by reducing the amount of catalyst used, in addition to increasing the efficiency of the coal liquefaction reaction by improving the catalyst activity. In order to realize this idea, it was considered important to increase the contact efficiency between coal and the catalyst, and thus came to the present invention. Table 2 below shows a comparison of the catalytic activity between the conventional mixing method and the supporting method according to the present invention. The reaction temperature is 450 ° C., and addition of sulfur as a co-catalyst has been indispensable in conventional coal liquefaction, but in this case, no sulfur was added.

As described above, the effect of catalyst addition was not remarkably observed in the mixing method. However, in the loading method, the amount of coal supported gradually increased with an increase in the amount of supported catalyst, and the conversion, It could easily exceed 90%.

[0026]

[Table 2] 量 Catalyst amount Coal conversion (wt%) (wt%) Holding method 0 82.0 76.4 1.8 83.1 78.8 5.9 84. 2 92.1 13.2 85.0 96.5}

Example 3 (Effect of reaction temperature) In this example, the influence of reaction temperature was shown. Again, no sulfur was added.

[0028]

[Table 3] 量 Catalyst load Reaction temperature (℃) (wt%) 400 425 450 ０ 0 50.9 69.1 76.4 0.8 48.8 72.1 79. 2 1.8 51.8 81.8 78.8 5.9 52.5 81.7 92.1 13.2 54.8 84.0 96.5} ────────────────

From these results, it is known that the reaction temperature is desirably 450 ° C., but it is known that the same coal reaction rate can be obtained even at 425 ° C. It is known that this also promotes the activation of coal itself by the method of the present invention.

Example 4 (Effect of Addition of Sulfur) In the examples up to this point, examples in which sulfur was not added were shown, but the effect when sulfur was added was examined.
The added sulfur was 5 wt% elemental sulfur based on the amount of the catalyst, and showed a coal conversion rate at a reaction temperature of 450 ° C.

[0031]

[Table 4] 触媒 Catalyst loading amount Sulfur yellow addition (wt%) No Yes ────────── ０ 076.4-0.6 79.2-1.8 78.8 83.3 5.9 92.1 92.0 13.2 96.5 96 .5───────────────────────

As is apparent from these results, the addition of sulfur has no effect on the conversion of coal. This is evidence that the catalyst supported on coal is not a pyrite-like iron sulfide as described above, but a completely new catalyst. It is also clear that the activity of the catalyst is considerably higher than that of the conventional pyrite catalyst.

[0033]

As described above, the present invention has been described in detail with reference to the examples. However, in general, since the catalyst used in the coal liquefaction reaction has a considerably high reaction temperature, a great disadvantage is that the amount of the catalyst to be added is considerably large. In order to solve this drawback, it is necessary to increase the activity of the catalyst and reduce the amount of catalyst added. The present invention
According to the present invention, it is possible to solve the drawbacks of these conventional methods, and by solving the drawbacks, it is possible to reduce the price of the reaction product and put the liquefaction process into practical use.
Therefore, if the coal liquefaction method using the catalyst loading method of the present invention is used, the amount of catalyst can be reduced without adding sulfur which is troublesome for the treatment after the reaction, and in addition, the activation of the coal itself is advanced. Therefore, it became clear that a more efficient liquefaction reaction can be realized.

Continuation of the front page (72) Inventor Tadashi Yoshida 2-1, 17-2, Tsukikanto, Toyohira-ku, Sapporo-city, Hokkaido Inside the Hokkaido Institute of Technology, Ministry of International Trade and Industry (72) Inventor Masahide Sasaki Toyohira-ku, Sapporo, Hokkaido Tsuruga Kanto 2-17-17-2 Inside the Hokkaido Institute of Technology, Ministry of International Trade and Industry (56) References JP-A-57-133190 (JP, A) JP-A-5-103988 (JP, A) Fuel Association Journal Vol. 70 No. 5 (1991) May 20, 1991 Published by The Fuel Association of Japan p. 431-439 (58) Field surveyed (Int.Cl. ⁶ , DB name) C10G 1/06 B01J 27/053 C10G 1/00

Claims (1)

(57) [Claims] A coal liquefaction method using a coal liquefaction reaction with a supported iron catalyst supported on coal using a urea decomposition method, wherein the supported iron catalyst converts coal into a predetermined amount of sulfuric acid. (2) To an aqueous solution in which iron and excess urea are dissolved with respect to iron, and by heating at a reaction temperature of 96 to 98 ° C. , the coal is impregnated with ferric sulfate. A coal liquefaction method characterized in that the catalyst is a supported iron-based catalyst which is neutralized to produce a sulfate-type iron catalyst and supported on coal.