JP2000109859A - Process and device for converting coal into fuel for generating unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently and easily produce from coals (CWM) a fuel for generating units comprising a combustible gas and COM, which is easily handled as substitute fuels for heavy oils and causes no dust pollution, to inhibit environmental pollution by easily converting sulfuric components contained in coals into harmless inorganic salts and removing them, to allow relatively little limitation on heat resistant properties and to allow miniaturization and increase the electric power generation efficiency of electric power generating devices. SOLUTION: A CWM wherein a finely powdered coal is mixed with water is maintained at a temperature and pressure of the subcritical or supercritical state of water to decompose the coal in a decomposition reactor 14. The obtained decomposed product is maintained at a temperature and pressure equal to or below the subcritical state of water in a separator 16 to be separated into an oil component, a hydrocarbon gas, a residue and water, The separated oil component and residue are mixed in a mixer 31 to generate COM. The hydrocarbon gas and COM are gasified into a combustible gas mainly comprising CO and H2 in a gasification reactor 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention decomposes coal / water mixture (hereinafter referred to as CWM) in subcritical or supercritical water, and decomposes combustible gas and coal / water from decomposition products generated by the decomposition. Oil mixture (hereinafter COM)
That. ), And a method and an apparatus for converting coal into fuel for power generation equipment.

[0002]

2. Description of the Related Art A CWM technology for preparing slurry CWM by adding water to pulverized coal and using it as a fuel alternative to heavy oil has been developed and put into practical use. However, in this CWM technology, water is added for the purpose of fluidizing the fuel. Therefore, even when high-quality coal is used as a raw material, the upper limit of the calorific value is only about 4500 kcal / kg, which is lower than that of ordinary heavy oil. Of course, there is a problem that the calorific value is considerably reduced as compared with the raw material coal.

[0003] As a power generation device, a thermal power generation device that converts combustion energy of fossil fuels such as coal and heavy oil into steam by a boiler and drives a steam turbine with the steam energy to generate power is known. In this power generation device, a large amount of sulfur and the like contained in fossil fuel is generated as impurities. For this reason, a thermal power generator requires a complicated purification device so that these impurities do not become harmful substances and cause environmental pollution. There is also a problem that high power generation efficiency cannot be obtained. In order to improve the power generation efficiency, as shown in FIG. 4, there is known a coal gasification combined power generation device 5 including a gasification reactor 1, a desulfurization device 2, and a combined power generation facility 3. In this power generation device 5, pulverized and dried coal is supplied to the upper furnace of the two-stage fluidized-bed type gasification reactor 1, and this coal is mixed with hot gas from the lower furnace and air as a gasifying agent entering the upper stage. Gasify. After the generated gas is taken out from the furnace top as a crude gas, it is sent to a heat recovery boiler 1c to recover heat. Heat recovery boiler 1
The crude gas that has passed through c is sent to the cyclone 1a. Unreacted char coarse particles that have not been gasified are collected by an inverted L-shaped overflow (not shown), and fine particles in the coarse gas are collected by a cyclone 1a. It is collected in the lower furnace and is burned again by air and steam to be gasified. Ash is taken out of the furnace bottom and stored in the tank 1b. The crude gas extracted from the cyclone 1a is sent to a desulfurizer 2, where a sulfur compound is combined with iron oxide to remove sulfur in the form of iron sulfide, and SO ₂ generated at that time is removed.
The gas is reduced to elemental sulfur and recovered. The crude gas taken out of the desulfurization device 2 is removed by a dust collector 2a and dust is removed by a dust separator 2b to become a combustible gas.

The combined power generation facility 3 includes a gas turbine 6a, a steam turbine 6b, a waste heat recovery boiler 9, a condenser 7, a first generator 8a, and a second generator 8b. Dust separator 2b
The combustible gas extracted from the gas turbine drives the gas turbine 6a,
First generator 8 whose rotation axis is directly connected to gas turbine 6a
The power is generated by a. Next, the exhaust gas from the gas turbine 6a is recovered by the exhaust heat recovery boiler 9 using the heat energy as steam energy. This steam energy is transferred to the steam turbine 6b.
And the second turbine 8b, whose rotating shaft is directly connected to the steam turbine 6b, generates electric power. The steam extracted from the steam turbine 6b is cooled by the condenser 7 to produce water, and a part of the water is supplied to the waste heat recovery boiler 9. The remainder of the water taken out of the condenser 7 is sent to the heat recovery boiler 1c, and generates steam by the heat of the crude gas. This steam is supplied to the steam turbine 6
b and is used as a part of the steam energy for driving the steam turbine 6b.

[0005]

However, in the gasification reactor in the integrated coal gasification combined cycle power plant, the decomposition of coal is not always sufficient, and a considerably large amount of char (hereinafter, referred to as residue) is generated. In order not to waste the residue, gasification is performed in two stages, or combustion of the residue is performed, so that the equipment becomes large and the control becomes complicated. Further, since gasification of coal is performed by thermal decomposition of coal, the reaction temperature is required to be about 1000 ° C. to 1200 ° C. or more. This limits the gasification reactor to many severe conditions to withstand high temperatures and increases thermal energy loss.

It is an object of the present invention to provide a 6000 to 9000 kc
An object of the present invention is to provide a method and an apparatus for converting fuel for power generation equipment from coal, which has a calorific value of about al / kg, is easy to handle as a heavy oil alternative fuel, and does not cause dust pollution, and its coal.
Another object of the present invention is to provide a method and an apparatus for converting coal into fuel for power generation equipment, which can efficiently and easily gasify coal in combination with a gasification reactor which is smaller than before. Another object of the present invention is to provide a method and an apparatus for converting coal into power generation facility fuel which does not cause environmental pollution by easily removing harmful inorganic salts contained in coal into harmless inorganic salts. is there. Still another object of the present invention is to provide a method for converting coal into fuel for power generation equipment and an apparatus thereof, which can enhance the power generation efficiency of the power generation device.

[0007]

The invention according to claim 1 is
A decomposition reaction step of decomposing the coal by maintaining the CWM obtained by mixing the pulverized coal and water at a temperature and pressure in a subcritical or supercritical state of water; and decomposing the decomposition product obtained in the decomposition reaction step into water. A separation step of separating the oil, hydrocarbon-based gas, residue and water by maintaining the temperature and pressure at or below the subcritical state, and mixing the oil and residue separated in this separation step to form COM. Power generation of coal including a step of producing and a step of supplying the hydrocarbon-based gas separated in the separation step and the COM to a gasification reactor to gasify the mixture into a combustible gas containing CO and H ₂ as main components. This is a method of switching to equipment fuel. The invention according to claim 3 is a decomposition reaction step of decomposing coal while maintaining the temperature and pressure of water in a subcritical state or a supercritical state of water mixed with finely divided coal and water; A separation step of separating the obtained decomposition products into water, a subcritical state of water or a temperature and pressure lower than that, to separate oil, hydrocarbon-based gas, residue and water, and an oil separated in this separation step. A method for converting coal into fuel for power generation equipment, comprising: a step of mixing the residue and the residue to generate COM; and a step of supplying the hydrocarbon-based gas separated in the separation step and the COM to a boiler and burning the same. It is. The invention according to claim 5 is a CWM in which pulverized coal and water are mixed.
A decomposition reaction step of decomposing coal by maintaining the temperature and pressure of water in a subcritical or supercritical state, and decomposing the decomposition product obtained in this decomposition reaction step at a temperature and a temperature lower than or equal to the subcritical state of water. A separation step of separating oil, hydrocarbon-based gas, residue and water while maintaining the pressure, and supplying the oil and hydrocarbon-based gas separated in this separation step to a gasification reactor,
A method for converting coal to fuel for power generation equipment, comprising a step of gasifying into a combustible gas containing O and H ₂ as a main component and a combustion step of supplying a residue separated in the separation step to a boiler and burning the residue is there. The invention according to claim 2, 4, or 6 is the invention according to claim 1, 3, or 5, respectively, and is a conversion method of adding an alkaline aqueous solution to CWM.

As shown in FIG. 1, the invention according to claim 7 includes a tank 11 for storing CWM in which finely divided coal and water are mixed, and maintaining the CWM in a subcritical state or a supercritical state of water. A cracking reactor 14 for cracking coal; and maintaining the cracked product obtained in the cracking reactor 14 in a subcritical state of water or at a temperature and pressure lower than that, oil, hydrocarbon gas, residue and water. A separator 31 that mixes the oil component and the residue separated by the separator 16 to generate COM, and a hydrocarbon-based gas and COM separated by the separator 16 into CO and H ₂ . This is a device for converting coal into fuel for power generation equipment, comprising a gasification reactor 20 that gasifies into a combustible gas as a main component. As shown in FIG. 2, the invention according to claim 8 comprises a tank 11 for storing a CWM in which pulverized coal and water are mixed, and maintaining the CWM in a subcritical state or a supercritical state of water to decompose coal. And the decomposition product obtained in the decomposition reactor 14 is separated into oil, hydrocarbon-based gas, residue and water while maintaining the temperature and pressure of water in a subcritical state or lower. The separator 16, a mixer 31 that mixes the oil component and the residue separated by the separator 16 to generate COM, and a boiler 23 that burns the COM and the hydrocarbon-based gas separated by the separator 16. This is a device for converting the provided coal into fuel for power generation facilities. The invention according to claim 9 is, as shown in FIG.
Tank 1 for storing CWM mixed with pulverized coal and water
1, a decomposition reactor 14 for decomposing coal by maintaining this CWM in a subcritical or supercritical state of water, and a decomposition product obtained in the decomposition A separator 16 for separating oil, hydrocarbon-based gas, residue and water while maintaining the temperature and pressure, and a separator 1
Gasification reactor 20 for gasifying the oil and hydrocarbon-based gas separated in 6 into a combustible gas containing CO and H ₂ as main components.
Boiler 2 that burns the residue separated by the separation device 16
3 for converting coal into fuel for power generation equipment.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the subcritical state of water is a temperature of 200 to 374 ° C. and 160 to 215 kg.
Means the state of water at a pressure of / cm ² . The supercritical state of water is a temperature of 374 to 900 ° C. and 215 to 3
It means the state of water at a pressure of 00 kg / cm ² . If the temperature and pressure in the subcritical state are less than the lower limits, the reaction is slow and the coal decomposition efficiency is not good. If the temperature and pressure in the supercritical state exceed the upper limits, the load on the decomposition reactor is too high, which is also inefficient. As shown in FIG. 1, in the apparatus for converting coal to fuel for power generation equipment according to the first embodiment of the present invention, a tank 11 stores a slurry-like CWM in which finely divided coal and water are mixed. Examples of coal include grass coal, lignite, sub-bituminous coal, bituminous coal, anthracite, and the like. When the coal contains sulfur, an alkaline aqueous solution is stored in the tank 11 to remove the sulfur. As the alkaline aqueous solution, NaOH, KOH, Ca
An aqueous solution such as (OH) ₂ is exemplified. The coal is finely ground in advance to a particle size of a few mm or less, preferably 300 μm or less depending on the capacity of the pump. The water in the CWM is added so that the CWM concentration is preferably 5 to 60% by weight.
If the CWM concentration is less than 5% by weight, the coal decomposition efficiency is poor,
If it exceeds 60% by weight, CWM lacks fluidity and becomes difficult to handle. The CWM concentration is more preferably from 10 to 55% by weight. The CWM stored in the tank 11 is pressure-fed by the pump 12, and the CWM pressure-fed by the heater 13.
Is heated to about 150 to 350 ° C. The CWM heated by the heater 13 is supplied to a decomposition reactor 14, where it is further pressurized and heated to a subcritical state or a supercritical state. Preferably at a temperature of 374-900 ° C. and 215-
500 kg / cm ² pressure, more preferably 374-6
A supercritical state at a temperature of 00 ° C. and a pressure of 215 to 450 kg / cm ² is employed.

[0010] In the cracking reaction device 14, the CWM in a subcritical state or a supercritical state is subjected to a hydrolysis reaction of coal,
It is considered that a thermal decomposition reaction and a hydrogenation reaction of coal occur. That is, in high-temperature water, non-covalent bonds such as hydrogen bonds in coal are dissociated, and the coal expands. Thereby, the decomposition and liquefaction reaction of coal proceeds more effectively. In the coal hydrolysis reaction, OH ⁻ and H ⁺ of H ₂ O are added to the hetero element portion connecting the benzene ring of the coal, and the coal is reduced in molecular weight. In the thermal decomposition reaction of coal, the coal is simply pyrolyzed and decomposed. Further, in the hydrogenation reaction, for example, H is added to the radical generated during the above reaction, whereby the thermally decomposed species is stabilized. In addition, a reaction occurs between a stable molecule that does not thermally decompose and active hydrogen. The above reactions (1) to (4) are not performed individually, but are performed simultaneously and in a complex manner, and lightening of coal proceeds. In this way, the coal is decomposed into oil and residue by the subcritical or supercritical state. Water in a supercritical state promotes the hydrolysis reaction of coal because the dissociation into hydrogen ions and hydroxyl ions is larger than normal water and at a higher temperature. Further, since water in a supercritical state has a small dielectric constant, it has a certain dissolving power in coal itself and can be uniformly mixed with gas. These also contribute to the promotion of lightening. CWM
Is a residue containing an oil component composed of heavy oil, medium / light oil and the like and an inorganic salt.

When the coal contains sulfur and the CWM contains an aqueous alkaline solution, the sulfur is supplied to the decomposition reactor 1
In step 4, the compound easily dissolves in water in a supercritical state via sulfur oxide (SOx) and becomes a harmless inorganic salt by the reaction of the following formulas (1) and (2). SO ₃ + H ₂ O → H ₂ SO ₄ (1) H ₂ SO ₄ + 2NaOH → Na ₂ SO ₄ + 2H ₂ O (2) That is, when the CWM of the tank 11 contains, for example, an aqueous solution of NaOH. The sulfur oxide (SO ₃ ) is converted into harmless sulfate (Na ₂ SO ₄ ) by the alkali (NaOH) aqueous solution.

The product decomposed in the decomposition reactor 14 is separated into oil and hydrocarbon gas, residue and water by lowering the temperature and pressure in the subcritical or supercritical state of water. Separating oil and residue at a high temperature requires less heat energy in the next step.
The decomposition products are preferably separated mainly by reducing the pressure thereof by the pressure reducing valve 15 and maintaining the subcritical or supercritical water at a high temperature in the separation device 16. This hydrocarbon-based gas contains high-temperature and high-pressure hydrogen, methane, ethane, benzene, and the like as main components. In addition, carbon dioxide (C
O ₂ ) is also separated from the separation device 16 and released into the atmosphere. The separated water is supplied to the decomposition reactor 14,
Recycled.

The oil and the residue separated by the separation device 16 are sent to a mixer 31 where they are mixed to generate COM. This COM is supplied by being injected into the gasification reactor 20 by a nozzle (not shown) or the like. The hydrocarbon-based gas separated by the separation device 16 is also supplied to the gasification reactor 20. CO supplied to the gasification reactor 20
M and hydrocarbon gases are used as gasifying agents in gasification reactor 2
And CO 2 and H _{2 at} high temperature and pressure
Becomes a combustible gas whose main component is. Ash, which is a residue of the gasification reactor 20, is taken out of the gasification reactor 20 and disposed. The combustible gas generated in the gasification reactor 20 is sent to the gas turbine 21 and burned by a combustor (not shown), and the combustion energy drives the gas turbine 21. The first generator 22 generates power by the rotational energy of the gas turbine 21. Thereby, power generation is performed with high power generation efficiency.

As shown in FIG. 2, in the conversion apparatus according to the second embodiment of the present invention, as in the first embodiment, the products decomposed by the decomposition reaction device 14 are separated into oil by the separation device 16. And hydrocarbon-based gas, residue and water. The oil component and the residue separated by the separation device 16 are sent to a mixer 31 and mixed to generate COM. This COM
Is supplied by being injected into the boiler 23 by a nozzle (not shown) or the like. The hydrocarbon-based gas separated by the separation device 16 is also supplied to the boiler 23. Boiler 23
The COM and the hydrocarbon-based gas are combusted, and steam energy is generated by heating water separately supplied to the boiler 23 with the combustion energy. This steam energy drives the first steam turbine 24 and the first steam turbine 2
The power is generated by the second generator 26, which is directly connected to the rotating shaft 4. The steam that has passed through the first steam turbine 24 is
And the water is supplied to the boiler 23 again.

As shown in FIG. 3, in the conversion apparatus according to the third embodiment of the present invention, similarly to the first embodiment, the products decomposed by the decomposition reaction device 14 are separated by the separation device 16 into oil components. And hydrocarbon-based gas, residue and water. The oil component and the hydrocarbon-based gas separated by the separation device 16 are supplied to the gasification reactor 20. The oil and hydrocarbon gas supplied to the gasification reactor 20 are used as a gasifying agent in the gasification reactor 2.
And CO 2 and H _{2 at} high temperature and pressure
Becomes a combustible gas whose main component is. Ash, which is a residue of the gasification reactor 20, is taken out of the gasification reactor 20 and disposed. The combustible gas generated in the gasification reactor 20 is sent to the gas turbine 21 and burned by a combustor (not shown), and the combustion energy drives the gas turbine 21. The first generator 22 generates power by the rotational energy of the gas turbine 21. The residue separated by the separation device 16 is supplied to the boiler 23. The residue is burned in the boiler 23, and steam energy is generated by heating water separately supplied to the boiler 23 with the combustion energy. Further, the exhaust gas of the gas turbine 21 is supplied to the boiler 23, and the water supplied to the boiler 23 is further heated by the thermal energy of the exhaust gas to generate steam energy. These steam energies drive the first steam turbine 24 and generate electric power by the second generator 26 having a rotating shaft directly connected to the first steam turbine 24. The steam that has passed through the first steam turbine 24 is cooled by the condenser 27 and supplied to the boiler 23 again.
As a result, the second generator 26 is operated together with the first generator 22, so that heat energy is effectively used for power generation and power generation is performed with high efficiency.

[0016]

As described above, the present invention decomposes and separates CWM in a subcritical or supercritical state to generate combustible gas and COM, and utilizes the combustion energy of this combustible gas and COM. Has the following excellent effects. (1) Compared with the conventional gasification reactor, the oil separated by the separation device of the present invention has good reactivity, and is relatively low in the form of COM alone or mixed with the residue in the gasification reactor. Since gasification can be performed at high temperature and at high speed, and gasification in two stages is not required, the size of the reaction furnace can be reduced, and there are few restrictions on the materials constituting the reaction furnace. (2) COM mixed oil and residue separated by separation device
Is supplied to the gasification reactor to produce combustible gas,
The supply of steam required by conventional gasifiers is reduced.

(3) Since the oil produced by the subcritical or supercritical reaction and separated from the separator has a high calorific value of about 8000 kcal / kg, the conventional gasification using only the cracked gas of coal The gas turbine efficiency can be remarkably improved as compared with the reactor, and the combustion exhaust temperature can be increased. As a result, the efficiency of the waste heat boiler and the steam turbine is also improved, and the efficiency of the entire combined cycle power generation can be improved. (4) The hydrocarbon-based gas generated by the subcritical or supercritical reaction and separated from the separation device is 3000 to 8000 kca.
It has a high calorific value of about 1 / Nm and can be burned in a boiler and used for steam generation. (5) If an alkaline aqueous solution is added together with the raw materials, the sulfur content in the coal can be removed in the form of an inorganic salt.
For this reason, a large-sized desulfurization unit used in the conventional combined cycle power generation device is not required, and low-grade coal, heavy oil, or the like having a relatively high sulfur content can be used as a raw material.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an apparatus for converting coal into fuel for power generation equipment and a power generation apparatus according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of an apparatus for converting coal into fuel for power generation equipment and a power generation apparatus according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram of an apparatus for converting coal into fuel for power generation equipment and a power generation apparatus according to a third embodiment of the present invention.

FIG. 4 is a configuration diagram of a conventional integrated coal gasification combined cycle device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Tank 13 Heater 14 Decomposition reaction device 15 Pressure reducing valve 16 Separation device 20 Gasification reaction furnace 23 Boiler 31 Mixer

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Akira Tanaka 1-3-25 Koishikawa, Bunkyo-ku, Tokyo Mitsubishi Materials Corporation System Business Center F-term (reference) 3G081 BA02 BA13 BA15 BB00 BC07 BD00 DA14 DA22 4D002 AA02 AC10 BA02 CA13 CA20 DA01 DA05 DA12 DA35 EA01 FA02 FA04 FA05 GA03 GB03 GB04 GB06

Claims (9)

[Claims] A decomposition reaction step of decomposing the coal by maintaining a coal / water mixture obtained by mixing finely divided coal and water at a temperature and pressure in a subcritical or supercritical state of water; and the decomposition reaction step Separation step of separating the decomposition product obtained in step 2 into oil, hydrocarbon-based gas, residue and water by maintaining the temperature and pressure of water in a subcritical state or lower, and separated in the separation step Mixing oil and residue to produce a coal-oil mixture, and the hydrocarbon-based gas separated in the separation step and the coal / oil mixture.
The oil mixture is supplied to the gasification reactor to supply CO and H ₂
Converting coal into fuel for power generation equipment, comprising: 2. The conversion method according to claim 1, wherein an alkaline aqueous solution is added to the coal / water mixture. 3. A decomposition reaction step of decomposing the coal by maintaining a coal / water mixture obtained by mixing finely divided coal and water at a temperature and pressure in a subcritical or supercritical state of water; and the decomposition reaction step. Separation step of separating the decomposition product obtained in step 2 into oil, hydrocarbon-based gas, residue and water by maintaining the temperature and pressure of water in a subcritical state or lower, and separated in the separation step Mixing oil and residue to produce a coal-oil mixture, and the hydrocarbon-based gas separated in the separation step and the coal / oil mixture.
A method for converting coal to fuel for power generation equipment, comprising: a combustion step of supplying oil mixture to a boiler and burning it. 4. The conversion method according to claim 3, wherein an alkaline aqueous solution is added to the coal / water mixture. 5. A decomposition reaction step of decomposing the coal while maintaining the temperature and pressure of water in a subcritical or supercritical state of a coal / water mixture obtained by mixing finely divided coal and water; and the decomposition reaction step. Separation step of separating the decomposition product obtained in step 2 into oil, hydrocarbon-based gas, residue and water by maintaining the temperature and pressure of water in a subcritical state or lower, and separated in the separation step A step of supplying an oil component and a hydrocarbon-based gas to a gasification reactor to gasify it into a combustible gas containing CO and H ₂ as a main component; and a step of supplying a residue separated in the separation step to a boiler and burning the residue. And a method for converting coal into fuel for power generation equipment. 6. The conversion method according to claim 5, wherein an alkaline aqueous solution is added to the coal / water mixture. 7. A tank (11) for storing a coal / water mixture in which pulverized coal and water are mixed, and decomposing the coal while maintaining the coal / water mixture in a subcritical state or a supercritical state of water. Decomposition reactor (14)
And maintaining the decomposition product obtained in the decomposition reaction device (14) in a subcritical state of water or at a temperature and pressure lower than that, and an oil component;
Separation device for separating hydrocarbon-based gas, residue and water (16)
A mixer (31) for mixing the oil component and the residue separated by the separation device (16) to generate a coal-oil mixture, and a hydrocarbon-based gas and the coal separated by the separation device (16). An apparatus for converting coal into fuel for power generation equipment, comprising a gasification reactor (20) for gasifying oil mixture into a combustible gas containing CO and H ₂ as main components. 8. A tank (11) for storing a coal / water mixture in which pulverized coal and water are mixed, and decomposing the coal while maintaining the coal / water mixture in a subcritical or supercritical state of water. Decomposition reactor (14)
And maintaining the decomposition product obtained in the decomposition reaction device (14) in a subcritical state of water or at a temperature and pressure lower than that, and an oil component;
Separation device for separating hydrocarbon-based gas, residue and water (16)
A mixer (31) for mixing the oil component and the residue separated by the separation device (16) to produce a coal-oil mixture, and a carbonization device separated by the coal-oil mixture and the separation device (16). An apparatus for converting coal into fuel for power generation equipment, comprising a boiler (23) for burning hydrogen-based gas. 9. A tank (11) for storing a coal / water mixture in which pulverized coal and water are mixed, and decomposing the coal while maintaining the coal / water mixture in a subcritical or supercritical state of water. Decomposition reactor (14)
And maintaining the decomposition product obtained in the decomposition reaction device (14) in a subcritical state of water or at a temperature and pressure lower than that, and an oil component;
Separation device for separating hydrocarbon-based gas, residue and water (16)
When, with the separation device gasification reactor to gasify the combustible gas and separated with oil hydrocarbon gas mainly composed of CO and H ₂ (16) (20), separated by the separation step An apparatus for converting coal to fuel for power generation equipment, comprising a boiler (23) for burning residues.