AU681983B2 - Process of coal liquefaction - Google Patents

Description

P/00/0 II Regulation 3.2

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

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S. S S I *5 0 TO BE COMPLETED BY APPLICANT *i~ne of Applicant: Actual Inventor(s): NIPPON BROWN COAL LIQUEFACTION CO., LTD Takao Kaneko; Toru Koyama; Kazuharu Tazawa; Koichi Sato; Jun Imai; Eiihiro Makino CALLINAN LAWRIE, 278 High Street, Kew, 3101, Victoria, Australia "PROCESS OF COAL LIQUEFACTION" Address for Service: Invention Title: The following statement is a full description of this invention, including the best method of performing it known to me:- 27/2i9LPWO.CS, -2- PROCESS OF COAL LIQUEFACTION BACKGROUND OF THE INVENTION 1. Field of the Invention: The present invention relates to a process of coal liquefaction, and more particularly, to a process of coal liquefaction including the step of hydrogenating coal in the presence of catalyst.

2. Description of the Prior Art: The recent resources and energy situation urgently requires the S development of a liquid fuel as a substitute for petroleum. One possibility of a .1 meeting this requirement is coal liquefaction in view of abundant coal reserves.

There have been proposed a variety of processes for coal liquefaction. A typical one of them consists of mixing dry pulverized coal with a solvent to give a slurry mixture and performing hydrogenation at a high temperature under a high pressure.

Such hydrogenation (liquefaction) of coal may require no catalyst, in S which case a certain component in coal functions as a catalyst. However, it is standard procedure to add a catalyst to the slurry mixture to promote hydrogenation. Thus it follows that coal hydrogenation is carried out in the presence of solvent and catalyst.

There have been known several catalysts to promote hydrogenation or to promote coal liquefaction. They include molybdenum compounds, chlorides (such as zinc chloride and tin chloride), and iron compounds (such as iron sulfide, iron sulfate, iron oxide, iron hydroxide, red mud, and iron ore).

2s2J96LPCOA ,DV2,2 -3- However, they are not satisfactory for coal liquefaction and involve several problems.

Catalysts for coal liquefaction should be active enough to promote hydrogenation. In addition, they should be cheap and readily available for economical coal liquefaction, and they should not cause trouble during operation. Unfortunately, molybdenum compounds are very expensive and limited in supply; chlorides tend to cause corrosion to the apparatus; and iron compounds are poor in catalytic activity although inexpensive.

Despite the above-mentioned problems, the iron-based catalyst, especially iron ore, is in general use for coal liquefaction because of its low price and abundant supply.

Iron ore as a catalyst for coal liquefaction is used in the form of mechanically pulverized fine particles so as to improve its catalyst activity, The pulverized iron ore is added to the above-mentioned slurry mixture for hydrogenation. The object of making iron ore into fine particles is to improve its dispersibility into the slurry and to increase the area of contact with coal (which oS is a requisite for high catalytic activity.

The mechanical pulverizing of iron ore may be accomplished by using a grinder (such as ball mill and tower mill) in the air or an inert gas (dry process) or in the presence of alcohol or petroleum solvent (wet process).

When used as a catalyst in the conventional process for coal liquefaction, the pulverized iron ore suffers a disadvantage of aggregating in the solvent, resulting in poor dispersion and insufficient contact with coal. This 28W29LPCOAL.DVZ,3 -4leads to a low catalytic activity, a low liquefaction rate, and a low oil yield.

In addition, the pulverized iron ore should be used in a large amount because of its inherently inefficient catalytic activity. For example, the amount of pyrite is 5-10 wt% of coas on dry ash-free basis. (Pyrite is commonly used because of its comparatively high catalytic activity). The high content of pulverized iron ore in the slurry mixture is a cause of erosion to the piping, pumps, valves, etc. Pulverizing a large amount of iron ore costs much.

Any attempt to reduce the amount of pulverized iron ore to solve the above-mentioned problem ends up with an insufficient catalytic activity, a low 0 liquefaction efficiency, and a low oil yield. Thus there is a demand for a process for coal liquefaction which affords a high oil yield even when the catalyst is used in an amount small enough to avoid problems with erosion.

Of the above-mentioned iron-based catalysts, iron hydroxide has a comparatively high catalytic activity. It is available in the form of limonite (mineral), amorphous iron hydroxide formed by neutralization and precipitation of a ferric salt, or a-iron oxyhydroxide (geothite) formed by neutralization and precipitation of a ferrous salt. However, the se conventional catalysts based on iron hydroxide do not have a sufficiently high catalytic activity to make coal liquefaction economically feasible. Thus there still is a demand for an economical process for coal liquefaction which affords a high oil yield with a high catalytic activity.

SUMMARY OL THE.INVENTION The present invention was completed in view of the foregoing. It is 28/2/96LPCOAL.DV2,4 I I an object of the present invention to provide a process for coal liquefaction which is capable of producing oil in a higher yield with a higher catalytic activity than the conventional process which employs pulverized iron ore as the catalyst.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram showing the process of coal liquefaction pertaining to the present invention.

Fig. 2 is a graph showing the relationship between the amount of the 0 catalyst and the yield of oil.

.1Q Fig. 3 is an X-ray diffraction pattern of Catalyst A pertaining to the invention.

Fig. 4 is a graph showing the relationship between the average particle diameter of the catalyst and the yield of oil.

DETAILED DESCRIPTION OF THE INVENTION The above-mentioned object is achieved by the process for coal e p.

liquefaction as defined below.

A process of coal liquefaction by hydrogenation of pulverized coal in the presence of solvent and catalyst, wherein the catalyst is y-iron oxyhydroxide which has been mechanically pulverized in the recycled solvent for coal liquefaction.

A process of coal liquefaction including the steps of hydrogenating pulverized coal in the presence of solvent and catalyst, separating the solvent from the hydrogenation product, introducing part of the separated solvent into a 21S296LPCOAL.DV2,5

I

-6pulverizer, and pulverizing y-iron oxyhydroxide in the solvent into pulverized y-iron oxyhydroxide having an average particle diameter not greater than 10 pm, wherein the pulverized y-iron oxyhydroxide is used as the catalyst.

A process of coal liquefaction including the steps of preparing a slurry mixture composed of coal, solvent, and catalyst, heating the slurry mixture for coal hydrogenation, separating oil fractions from the hydrogenation product, recycling part of the solvent (as part of the separated oil fractions) to the step of preparing a slurry mixture, introducing part of the solvent separated from the oil fractions into a pulverizer, pulverizing y-iron oxyhydroxide in the solvent into pulverized y-iron oxyhydroxide having an average particle diameter not greater than 10 pm, wherein the pulverized y-iron oxyhydroxide is used as the catalyst.

A process of coal liquefaction as described in the above paragraphs wherein the amount of the catalyst is 0.1-10 wt% of the amount of coal on dry ash-free basis.

A process of coal liquefaction including the step of hydrogenating t o coal in the presence of solvent and catalyst, wherein the catalyst is y-iron oxyhydroxide.

A process of coal liquefaction including the step of hydrogenating coal in the presence of solvent and catalyst, wherein the catalyst is y-iron oxyhydroxide powder having an average particle diameter not greater than pnr, which has been mechanically pulverized in the recycled solvent for coal liquefaction.

2aa/w.LPcoALv2, I C1 I-1LP, -7- A process of coal liquefaction as described above wherein coal, solvent, and catalyst coexist with sulfur (as a simple compound) or a sulfur compound.

The present invention resulted from researches on catalysts capable of coal liquefaction in high yields. It turned out that y-iron oxyhydroxide has a higher catalytic activity than conventional iron hydroxide catalyst and exhibits a high oil yield.

As mentioned above, coal liquefaction by the process of the present invention employs as the catalyst y-iron oxyhydroxide mechanically pulverized in a.

the recycled solvent for coal liquefaction. Such pulverized y-iron oxyhydroxide is readily dispersible in the solvent with little tendency to aggregation, which leads to good contact with coal, high catalytic activity, high liquefaction efficiency, and high oil yields. This effect is not produced if iron ore is pulverized by dry process or by wet process in alcohol or common petroleum solvent.

By "recycled solvent for coal liquefaction" is meant a solvent used to prepare a slurry mixture of coal, solvent, and catalyst. In the course of hydrogenation, this solvent is recovered from the hydrogenation product by distillation. Subsequently, the recovered solvent is mostly recycled to the step of slurry preparation and partly supplied to the other steps. That is, the recycled solvent is partly supplied to the grinder for use as a grinding medium of iron ore.

The solvent used for preparing a slurry mixture is a petroleum solvent 2=SP96LPCOAL,DV2,7 c I sl -8selected from fractions having a boiling point of 180-450°C, depending on the reaction conditions employed for coal liquefaction. During recycling between the slurry preparation and the solvent recovery, it changes in its properties and, after operation for tens of hours, it becomes to exhibit almost invariable properties.

Since coal liquefaction needs a huge amount of recycled solvent (which is 1-3 times as much as coal), it is common practice to use as the recycled solvent part of oil (especially middle oil and/or heavy oil rather than light oil) separated after liquefaction.

*A1 The process of coal liquefaction in accordance with the invention should preferably employ the catalyst in an amount of 0.1-10 wt% of coal on dry ash-free basis as defined in Claim 4. With an amount less than 0.1 wt%, the catalyst does not afford the desired yield of oil. With an amount in excess of 10 wt%, the catalyst causes erosion to the apparatus. An adequate amount a is 0.5-8 wt% from the standpoint of economy (pulverizing cost and yields).

:There are no restrictions on the method of separating solvent or oil from the hydrogenation product. Separation may be accomplished by distillation (under conditions adequate for desired products) or filtration.

Research on coal liquefaction catalyzed by y-iron oxyhydroxide revealed that y-iron oxyhydroxide has a much higher catalytic activity than the conventional iron catalyst, iron hydroxide catalyst, and pulverized iron ore catalyst and hence affords a high oil yield. This finding led to a process of coal liquefaction including the step of hydrogenating coal in the presence of solvent 282/96LPCOAL.DV2,8 I 9 1 It Is 9 -9and catalyst, wherein the catalyst is y-iron oxyhydroxide. Because of its much higher catalytic activity than pulverized iron ore catalyst and iron hydroxide catalyst, y-iron oxyhydroxide affords a greatly improved oil yield.

The y-iron oxyhydroxide is used as the catalyst for coal liquefaction after pulverizing as in the case of the conventional iron hydroxide catalyst.

The pulverized y-iron oxyhydroxide catalyst should preferably have an average particle diameter not greater than 10 pm. The average particle diameter should preferably be not greater than 5 pm, most desirably not greater than 1 pm.

0 q'0 The pulverized y-iron oxyhydroxide catalyst specified above should be prepared by mechanical pulverizing in the recycled solvent for coal liquefaction.

Pulverizing of y-iron oxyhydroxide in the recycled solvent for coal 9 liquefaction may be accomplished in the same manner as described in patent application 81710/94.

A probable reason why y-iron oxyhydroxide has a much higher catalytic activity than the conventional iron hydroxide catalyst is its small average particle size, its high specific surface area, and its unique morphology of active species. Iron-based catalysts (to which iron hydroxide catalysts belong) have the property in common that their active species is a sulfide called pyrrhotite. (Iron hydroxide catalysts and iron-based catalysts function in the form of sulfide for coal liquefaction). However, they differ in average particle diameter and specific surface area and hence differ in activity accordingly.

To test for catalytic activity, a sample of iron hydroxide catalysts was 28/2/96LPCOALDV2,9 II L-T sulfided in 1-methylnaphthalene containing sulfur under pressurized hydrogen.

The resulting pyrrhotite recovered after the reaction was examined for specific surface area. It was found that the specific surface area greatly decreases after the reaction; however, it was also found that pyrrhotite recovered from y-iron oxyhydroxide after the reaction has a greater specific surface area than that recovered from a-iron oxyhydroxide (one of the conventional iron hydroxide catalysts) after the reaction.

The foregoing suggests that the higher catalytic activity of y-iron oxyhydroxide compared with the conventional iron hydroxide catalyst is due to the fact that y-iron oxyhydroxide gives rise to pyrrhotite (as the active species) which has a large specific surface area.

As mentioned above, in the process of coal liquefaction in the present invention, y-iron oxyhydroxide functions as a catalyst in the form of sulfide. Therefore, it is necessary that the y-iron oxyhydroxide be sulfided before the hydrogenation of coal is carried out. The sulfidation of the y-iron oxyhydroxide may take place if coal in the slurry contains a comparatively large amount of sulfur or sulfur compound. However, for complete sulfidation, it is 0 0 desirable to add sulfur (as a simple substance) or a sulfur compound to the slurry mixture. Alternatively, in the case where the content of sulfur or sulfur G. compounds in coal is low, it is also possible to completely sulfide y-iron oxyhydroxide by adding sulfur (as a simple substance) or a sulfur compound to the slurry mixture. In addition, it is possible to ensure catalytic activity by sulfiding y-iron oxyhydroxide before its addition to the slurry mixture.

No restrictions are imposed on the process of producing y-iron oxyhydroxide. A conventional process that can be employed may consist of adding an alkaline aqueous solution of sodium hydroxide or ammonia to an aqueous solution of ferrous sulfate or ferrous chloride, thereby forming a slurry of ferrous hydroxide precipitates, adding to the slurry an aqueous solution of 24/617L1'COA..DV2.10 ~LLI~-I~ 11 disodium hydrogenphosphate or diammonium hydrogenphosphate, oxidizing the precipitates by bubbling air, thereby forming precipitates of y-iron oxyhydroxide, and washing, drying, and crushing the precipitates.

The process of coal liquefaction of the present invention may be applied to brown coal (with a low degree of coalification), subbituminous coal, and bituminous coal. Usually coal is used the form of particles, finer than about 60 mesh, pulverized after drying to a water content less than ,o Pulverized coal is favorable to liquefaction.

Hydrogenation may be carried out under any conditions; usually at ,O 350-500°C for 10-120 minutes, with the hydrogen partial pressure being 7-20 MPa. The hydrogenation product is separated from solids such as catalysts and recovered as such (in the form of oil) or fed to a distillation column for separation into desired fractions (such as heavy oil, middle oil, and o light oil). Part of the heavy oil (as the recycled solvent) is recycled to the step of slurry preparation.

EXAMPLES

S o.

The invention will be described in more detail with referencs to the following preferred examples.

Example 1 Coal liquefaction was carried out according to the flowsheet in Fig. 1.

The process starts with the preparation of a slurry. The coal slurry preparing vessel is charged with dry pulverized coal, part of the recycled solvent recovered from the distillation column mechanically pulverized iron wt LpUCOAl.,DV,II C- r I_ y Pk i- 12 ore catalyst, and sulfur (cocatalyst) recovered from the desulfurizer They are mixed into a slurry mixture. The pulverized iron ore catalyst is prepared by mechanicaily pulverizing iron ore in a grinder containing part of the recycled solvent. Pulverizing is carried out to give particles having an average particle diameter not greater than 10 pm.

The slurry mixture is transported to the preheater via the slurry pump. In the course of transportation, hydrogen is added. The slurry is introduced into the reactor of continuous stirred tank type, flow tubular type, or bubble column type. Liquefaction in the reactor is carried out at 380- 0* .40 480 0 C for 10-60 minutes under a hydrogen pressure of 6-25 MPa. Up to this point, the feed coal undergoes dissolution and extraction with the recycled 0• solvent and hydrogenation and decomposition by the catalyst, and becomes S. S soft, turning into the desired product.

S• After the completion of liquefaction, the reaction mixture is introduced into the gas-liquid separator The liquid free gas is transferred to the desulfurizer in which sulfur is recovered. The recovered sulfur is transferred to the coal slurry preparing vessel and other gas components are recovered as offgas.

The solids and liquids remaining in the gas-liquid separator are transferred to the distillation column in which they are separated into light oil, middle oil, and heavy oil as products. Part of the middle oil and heavy oil (as the recycled solvent) is partly recycled to the coal slurry preparing vessel At the same time, part of the middle oil and heavy oil (as the recycleo 2296iLPCOAL.DV2,12 CP4jI 13solvent) is introduced into the pulverizer in which iion ore is mechanically pulverized. The resulting pulverized iron ore catalyst is supplied to the coal slurry preparing vessel Simultaneously, dry pulverized coal is also supplied to the coal slurry preparing vessel After repetition of the above-mentioned procedure, it was found that the pulverized iron ore catalyst did not aggregate but remained completely dispersed in the solvent of the slurry mixture. In addition, the catalyst was active enough for the desired effect.

Comparative Example 1 .49 Natural pyrite was pulverized to give pulverized pyrite catalyst having l an average particle diameter of 2.6 pm. The same procedure as in Example 3 was repeated except that the sulfided catalyst of pulverized wolframite was S replaced by the pulverized pyrite catalyst and sulfur was not added. The yield o of oil (C 5 to fractions having a boiling point lower than 420 0 C) was 24.8 wt% of coal on dry ash-free basis.

Incidentally, the amount of the catalyst added (or the content of the pulverized pyrite catalyst in the slurry mixture) was 3.0 wt% (as pyrite) of coai on dry ash-free basis. This catalyst amount is substantially equivalent to the catalyst amount in Example 1 of co-pending application No.

Example 2 A catalyst of y-iron oxyhydroxide was prepared in the following manner. A 5-liter flask was charged with 2500 ml of 0.3 mol/L aqueous solution of ferrous sulfate. To the flask was added dropwise 638 g of 28s96PCOALDV,13 -14- 3.4 wt% aqueous solution of ammonia under a nitrogen stream. The reaction formed precipitates. To the flask was further added an aqueous solution composed of 20 g of pure water and 1.684 g of diammonium hydrogenphosphate. The reactants were stirred at 40 0 C by bubbling air at a rate of 3 N L/min. Air bubbling was suspended when the pH of the liquid decreased to 4. The resulting precipitates were washed three times by decantation and then filtered through a membrane filter. The filter cake was vacuum-dried at 550C. The dried filter cake was crushed using a porcelain

C*

0 mortar to give a powder having an average particle diameter of 20 pm. This powder was identified by X-ray diffractometry as y-iron oxyhydroxide as shown in Fig. 3. It was also found that this powder has a specific surface area of 62 m 2 /g (measured by the nitrogen adsorption BET method). This powder is referred to as "Catalyst A" hereinafter.

4* g(b) Catalyst A was mechanically pulverized in the recycled solvent for brown coal liquefaction using a planetary mill (Model P-5 made by Fritche Co.) containing balls with a diameter of 10 mm. Thus there was obtained a slurry of y-iron oxyhydroxide catalyst. The measurement of particle size distribution by laser diffractometry indicates that the catalyst has an average particle diameter of 1.2 pm.

A slurry mixture was prepared from brown coal (from Australia), the y-iron oxyhydroxide catalyst slurry, sulfur, and solvent for liquefaction. The amount of the y-iron oxyhydroxide catalyst slurry was wt% (as y-iron oxyhydroxide) of coal on dry ash-free basis. The amount of 28/2JLPCOALDV2,14 15 sulfur was 2.1 wt% of coal on dry ash-free basis.

The thus prepared slurry mixture was placed in a autoclave, and hydrogenation (liquefaction) was carried out at 450°C for minutes under an initial hydrogen pressure of 7.5 MPa. The resulting reaction product was separated and distilled for fractionation. The yield of oil (C5 to fractions having a boiling point lower than 420 0 C) was 51 wt% of coal on dry ash-free basis, as shown in Fig. 4 (the right circle).

Example 3 Catalyst A (obtained in Example 1) was pulverized in the recycled S o solvent for brown coal liquefaction using a planetary mill containing balls with a diameter of 2.4 mm. Thus there was obtained a y-iron oxyhydroxide catalyst slurry. This catalyst has an average particle diameter of 0.4pm. A slurry mixture was prepared in the same manner as in Example 1, except that the yiron oxyhydroxide catalyst slurry (having an average particle diameter of 1 5 1.2 pm) was replaced by the above-mentioned y-iron oxyhydroxide catalyst S slurry (having an average particle diameter of 0.4 pm). Using this slurry 0 mixture, hydrogenation and fractionation were carried out in the same manner as in Example 1. The yield of oil to fractions having a boiling point lower than 420C) was 56 wt% of coal on dry ash-free basis, as shown in Fig, 4 (the left circle).

Comparative Example 2 a-iron oxyhydroxide catalyst in the form of powder having an average particle diameter of 18 pm was prepared in the same manner as in 28~2%L*cOAL.DYV2.1 I I -16- Example 2, except that the amount of 3.4 wt% aqueous solution of ammonia was changed to 563 g and the aqueous solution of diammonium hydrogen phosphate was not added. This powder was identified as a-iron oxyhydroxide and was found to have a spec-iic surface area of 80 m 2 This powder is referred to as "Catalyst B" hereinafter.

Catalyst B was mechanically pulverized in the recycled solvent for brown coal liquefaction using a planetary mill containing balls with a 0 diameter of 2.4 mm. Thus there was obtained a slurry of a-iron oxyhydroxide catalyst. This catalyst was found to have an average particle diameter of 0.8 0 0 pm.

A slurry mixture was prepared in the same manner as in Exampie 2, except that they y-iron oxyhydroxide catalyst slurry was replaced by the a-iron oxyhydroxide catalyst slurry. Hydrogenation and fractionation were carried out in the same manner as in Example 2. The yield of oil (Cs to fractions having a boiling point lower than 4200C) was 44 wt% of coal on dry ash-free basis, as shown in Fig. 4 (the left square).

:0 Comparative Example 3 Catalyst B (obtained in Comparative Example 2) was pulverized in the recycled solvent for brown coal liquefaction using a planetary mill containilng balls with a diameter of 10 mm. Thus there was obtained an a-iron oxyhydroxide catalyst slurry. This catalyst has an average particle diameter of 1.8 pm. A slurry mixture was prepared in the same manner as in Example 2, except that the y-iron oxyhydroxide catalyst slurry was replaced by the above- 28 r LPCOA,,PV2t6 17 mentioned a-iron oxyhydroxide catalyst slurry. Using this slurry mixture, hydrogenation and fractionation were carried out in the same manner as in Example 2. The yield of oil (C 5 to fractions having a boiling point lower than 420 0 C) was 38 wt% of coal on dry ash-free basis, as shown in Fig. 4 (the right square).

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MMU/6LCOALD20r7 -18- Comparative Example 4 Natural pyrite (iron ore) was pulverized using a pneumatic pulverizer (made by Nisshin Engineering Co., Ltd.). Thus there was obtained a pulverized pyrite catalyst having an average particle diameter of 2.6 pm. This catalyst is referred to as "Catalyst C" hereinafter. A slurry mixture was prepared from brown coal (from Australia), Catalyst C, and solvent for coal liquefaction. The amount of Catalyst C was 7.0 wt% (as pyrite) of coal on dry ash-free basis.

Hydrogenation and fractionation were carried out in the same manner as in Example 2, except that the y-iron oxyhydroxide catalyst slurry was replaced by oC

R,:

the above mentioned slurry mixture. The yield of oil (C 5 to fractions having a boiling point lower than 420 0 C) was 33 wt% of coal on dry ash-free basis, as S shown in Fig. 4 (the right triangle).

Comparative Example Catalyst C (obtained in Comparative Example 4) was pulverized using a pneumatic pulverizer to give a pulverized pyrite catalyst having an average particle diameter of 0.5 pm. A slurry mixture was prepared in the same manner as in Comparative Example 4, except that the pulverized pyrite catalyst (having an average particle diameter of 2.6 pm) was replaced by the pulverized pyrite catalyst (having an average particle diameter of 0.5 pm). Using this slurry mixture, hydrogenation and fractionation were carried out in the same manner as in Comparative Example 4 (or Example The yield of oil (C 5 to fractions having a boiling point lower than 420°C) was 39 wt% of coal on dry ash-free basis, as shown in Fig. 4 (the left triangle).

2/2/96U'COALDV2i8 I, I -19- It was demonstrated that the process of coal liquefaction in the present invention permits higher oil yields owing to the high catalytic activity than the conventional process that employs pulverized iron ore catalyst.

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Claims (3)

1. A process of coal liquefaction including the step of hydrogenating coal in the presence of solvent and catalyst, wherein the catalyst is y-iron oxyhydroxide.

2. A process of coal liquefaction including the step of hydrogenating coal in the presence of solvent and catalyst, wherein the catalyst is y-iron oxyhydroxide powder having an average particle diameter not greater than 10 pm which has been mechanically pulverized in the recycled solvent for coal liquefaction.

4.Q: 3. A process of coal liquefaction as defined in Claim 1 wherein the average particle diameter of the catalyst is not greater than 10 pm. 9u,. 4. A process of coal liquefaction as defined in any one of Claims 1 to 3 wherein coal, solvent, and catalyst coexist with sulfur (as a simple substance) or a sulfur compound. 99 D A T E D this 25th day of June, 1997. NIPPON BROWN COAL LIQUEFACTION CO., LTD By their Patent Attorneys: CALLINAN LAWRIE 241697LPCOAL.DV220 I- I "s~ 4 1 1 ABSTRACT A process of coal liquefaction is provided by hydrogenation of pulverised coal in the presence of solvent and y-iron oxyhydroxide as catalyst. p 9**9 0**9 4 4 4@ 4. 0 *000 0* 4 4. 4* 0 0 0* 0* 2W/2961P96WQ,AW3,1