JPH10237458A - Apparatus for continuous conversion of coal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus by which coal can be continuously converted into a more volatilizable component, this component can be liquefied, the product of liquefaction can be continuously fractionated into a heavy oil, a middle oil and a light oil, and the residue left after the liquefaction of coal can be utilized to generate active hydrogen and by which the reaction time is very short, the efficiency of conversion is high and the conversion cost is low as compared with prior art. SOLUTION: This apparatus consists of a fluidized bed reaction tower 10 in which a fluidizing medium formed so as to be kept in a supercritical state and based on an inside iron oxide is fed with carbon dioxide being a fluidizing gas together with supercritical water. Pulverized coal is fed into the medium to convert the coal into a more volatilizable component and this component is converted into an oil and a fractionation apparatus 20 whereby the supercritical water containing the oil formed in the tower 19 is reduced in pressure in stages and cooled to fractionate the formed oil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus for continuously converting coal into oil or the like in a supercritical state. More particularly, the present invention relates to an apparatus for lightening coal by adding active hydrogen to coal and continuously converting the coal into a fuel oil or a useful compound or mixture.

[0002]

2. Description of the Related Art Conventionally, as a method of liquefying coal by adding hydrogen, a method of adding molecular hydrogen gas to coal in the presence of a catalyst such as Ni, Co, Fe or the like to lighten the coal and liquefy the coal is known. It has been known. As another method, a method is known in which hydrogen is added to coal by using a hydrogen-donating solvent to lighten and liquefy the coal.

[0003]

The hydrogen required in these technologies is about 5 to about 8% by weight of coal weight.
It extends to. These techniques are based on the premise that expensive hydrogen gas or hydrogen produced by gasification of coal is used. For this reason, the cost of hydrogen gas and the cost for hydrogen production in the liquefaction cost of coal increase, and as a result, a low-cost alternative to the coal conversion process is desired. Further, the conventional method is a method of pyrolyzing coal at high temperature and reacting with hydrogen under a catalyst.However, when the reaction is slow and the amount of conversion is increased in a predetermined number of days, a large number of reactors are provided, or The reactor had to be upsized.

[0004] It is an object of the present invention to provide a continuous coal conversion apparatus for continuously lightening and liquefying coal and continuously fractionating heavy oil, medium oil and light oil from liquefied matter. It is in. Another object of the present invention is to provide a continuous coal conversion apparatus that utilizes the residue after liquefaction of coal to produce active hydrogen. Still another object of the present invention is to provide a continuous coal conversion apparatus in which the reaction time is extremely short as compared with the conventional apparatus, the conversion efficiency is high, and the conversion cost is reduced.

[0005]

The invention according to claim 1 is
As shown in FIG. 1, carbon monoxide is supplied as a fluid gas together with water in a supercritical state to a fluid medium inside which can be maintained in a supercritical state, and pulverized coal is supplied to the fluid medium. A fluidized bed reactor 10 for reducing the amount of oil to produce oil, a fractionating apparatus 20 for fractionating the supercritical water containing oil generated in the reactor 10 by gradually reducing and cooling the oil and fractionating the generated oil. It is a continuous coal conversion device provided with. When carbon monoxide is supplied to the pulverized coal in the fluidized state together with water in the supercritical state from the lower part of the fluidized bed reactor 10 formed so as to be maintained in the supercritical state, a lightening reaction of the coal is performed. . In the present specification, the supercritical state is a temperature of 374 to 374.
A state in which the density is 800 to 900 g / cm ³ at 800 ° C. Below the lower limit of the above temperature range and density range, the reaction is slow and conversion efficiency is not good. If the temperature range and the density range exceed the upper limits, the reactor is overloaded, which is not efficient. This temperature is more preferably 400 to 600 ° C., and the density is more preferably 0.1 to 0.6 g / cm ³ .

The supercritical coal lightening reaction includes a coal hydrolysis reaction, a coal thermal decomposition reaction, and a hydrogenation reaction. The coal of the hydrolysis reaction, the hetero element portion which connects the benzene ring of coal H ₂ O OH ^- is added, the coal is depolymerized. In the thermal decomposition reaction of coal, the coal is simply pyrolyzed and decomposed. Further, in the hydrogenation reaction, H is added to the radicals generated in the above, thereby stabilizing the thermally decomposed species. Here, a hydrogenation reaction can also occur in the hydrolyzed species, but the hydrogen reaction to the above radical occurs more predominantly. The term "hydrogenation reaction" as used herein also includes the reaction described above for the hydrolysis reaction in which coal is decomposed by addition of H to the coal itself to lower the molecular weight. However, the above-mentioned reactions are not performed individually, but are performed in competition with each other,
Lightening of coal progresses. The oil produced by lightening the coal in the fluidized bed reactor 10 is discharged from the upper part of the reactor,
The fractionation device 20 separates the oil into heavy oil, medium oil and light oil.

The invention according to claim 2 is the invention according to claim 1, wherein the fluidized medium of the fluidized bed type reaction tower 10 has a mean particle diameter of 0.3 to 5 mm mainly composed of iron oxide. This is a continuous conversion device for coal, which is granular. The fluidized medium favorably maintains the fluidized bed in the reaction tower, the iron oxide also acts as a catalyst for lightening the produced oil, and prevents scaling of ash and the like on the inner wall surface of the reaction tower. When the average particle size of the sintered particles is out of the above range, the fluidized bed is not maintained well, and the effect of preventing scaling of ash and the like becomes insufficient.

The invention according to claim 3 is the invention according to claim 1 or 2, wherein the fluidized bed type reaction tower 10 and the fractionating apparatus 20
Between 0.3 and 5 m in average particle diameter mainly composed of iron oxide
This is a continuous coal conversion apparatus equipped with an oil reformer 19 filled with m sintered particles. The sintered granules in the oil reformer 19 serve as a catalyst to further lighten the oil generated in the reaction tower 10.

The invention according to claim 4 is the invention according to claim 3, wherein the fractionating apparatus 20 comprises a heavy oil separator 21, a medium oil separator 22, a light oil separator 23, and a gas-liquid separator. 24, the oil reformed by the oil reformer 19 is a heavy oil separator 21,
This is a continuous coal conversion apparatus configured to be depressurized and cooled in the order of the medium oil separator 22 and the light oil separator 23. By providing the heavy oil separator 21, the medium oil separator 22, and the light oil separator 23, a plurality of types of oil can be appropriately separated and recovered for each property. Further, in the gas-liquid separator 24, carbon dioxide and water are separated, and the carbon dioxide is released to the atmosphere.

The invention according to claim 5 is the invention according to claims 1 to 3
Wherein the fluidized bed reactor 10 comprises a primary reactor 11 and a secondary reactor 12 each formed so as to be maintained in a supercritical state. The reaction product is supplied to the secondary reaction tower 12, and carbon monoxide is supplied as a flowing gas together with supercritical water to each of the fluidized media inside the primary and secondary reaction towers 11, 12. It is a configured continuous coal conversion device. 2 reaction towers
By providing one, the residence time of the pulverized coal in the reaction tower can be lengthened, and the lightening reaction of coal can be performed more reliably.

The invention according to claim 6 is the invention according to claims 1 to 3
In the invention according to any one of the above, oxygen is supplied as a flowing gas to the internal fluid medium that is formed so as to be maintained in a supercritical state, and the residual coal generated in the fluidized bed reactor 10 is supplied to the fluid medium. A continuous coal conversion apparatus comprising a fluidized bed partial oxidation reaction tower 13 for producing carbon monoxide, and configured to supply the carbon monoxide generated in the partial oxidation reaction tower 13 to the reaction tower 10 as a fluidized gas. It is. The carbon in the char is partially oxidized to carbon monoxide by adding oxygen in a supercritical state to the residual coal (char) generated in the fluidized bed reactor 10 in the partial oxidation reactor 13. Here, the char is the one that has not been completely decomposed or the one that has been re-polymerized by the pyrolysis reaction of the coal and the pyrolysis reaction of the coal. The carbon monoxide generated in the partial oxidation reaction tower 13 is supplied from the lower part to the fluidized bed type reaction tower 10 together with supercritical water, where active hydrogen is generated, and this active hydrogen is used for reaction with unreacted coal. It is a method of converting coal.

In the partial oxidation reaction tower 13, a reaction represented by the following equation (1) occurs. 2C + O ₂ → 2CO (1) As shown in the formula (1), char which is a residue produced by coal liquefaction is partially oxidized to carbon monoxide, and the fluidized bed reactor 1
At 0, a water gas shift reaction represented by the following formula (2) is caused to generate active hydrogen. In the water gas shift reaction of the formula (2), CO generated by partial oxidation is immediately reacted with H ₂ O. CO + H ₂ O → CO ₂ + H ₂ (2) The active hydrogen generated by the above formula (2) is used in the above-mentioned hydrogenation reaction. As a result, the residue of the fluidized bed type reaction tower 10 can be effectively used, and the volume of waste discharged from the apparatus of the present invention can be reduced.

The invention according to claim 7 is the invention according to claim 6, wherein the fluidized medium of the fluidized bed partial oxidation reaction tower 13 has an average particle diameter of 0.3 to 5 mm mainly composed of iron oxide. This is a continuous converter for coal, which is a sintered granule. The sintered particles in the reaction tower 13 serve as a catalyst to further promote partial oxidation of the char.

The invention according to claim 8 is the invention according to claim 6 or 7, comprising an ash receiving hopper 17 for collecting powdery ash generated in the fluidized bed type partial oxidation reaction tower 13,
This is a continuous coal conversion apparatus configured to supply calcium oxide to the ash receiving hopper 17 to generate calcium sulfate from sulfur in the ash. As a result, the ash and calcium sulfate discharged from the partial oxidation reaction tower 13 can be simultaneously dry-recovered.

[0015]

Embodiments of the present invention will now be described with reference to the drawings. As shown in FIG. 1, the fluidized bed reactor 10 has a primary reactor 11 and a secondary reactor 12. The primary and secondary reaction towers 11 and 12 are formed in a thick cylindrical shape so as to maintain a supercritical state, and the reaction products of the primary reaction tower 11 are supplied to the secondary reaction tower 12. Has become. Inside the reaction towers 11 and 12, fluidized media of sintered particles having an average particle diameter of 3 mm and containing iron oxide as a main component are stored, respectively, and carbon monoxide flows together with supercritical water in the fluidized media. It is supplied as a gas to form a fluidized bed. 1
Coal supply hoppers 11a and 11b are provided in series at a raw material supply port of the next reaction tower 11. Valves (not shown) are provided on the supply side and the discharge side of the hopper 11b, respectively, so as to maintain the supercritical state of the reaction tower 11 during coal supply. The first hopper 11a is supplied with coal pulverized to a size of 32 mesh under (about 200 μm).
As this coal, grass coal, lignite, sub-bituminous coal or bituminous coal is preferred because of its high liquefaction efficiency. In addition, these coal types with relatively large reserves can be used effectively and are compatible with the natural environment.

At the residue outlet of the secondary reactor 12, a residue receiving hopper 12a and a residue supply hopper 12b are provided in series. The residue supply hopper 12b is a fluidized bed type partial oxidation reaction tower 13 formed in a thick cylindrical shape so as to maintain a supercritical state.
Connected to the raw material supply port. Valves (not shown) are provided on the supply side and the discharge side of the hoppers 12a and 12b, respectively, so as to maintain the supercritical state of the reaction tower 12 and the reaction tower 13 at the time of receiving and supplying the residue, respectively. Inside the reaction tower 13, a fluidized medium of sintered particles having an average particle diameter of 3 mm and containing iron oxide as a main component is stored. And a fluidized bed is formed. In the reaction tower 13, the residual coal generated in the secondary reaction tower 12 is supplied to the fluid medium to generate carbon monoxide, and the generated carbon monoxide is supplied to a solid-gas separation provided at the upper part of the reaction tower 13. Mixed with supercritical water in mixer 15 through filter 13a,
The gas is supplied to the primary and secondary reaction towers 11 and 12 as a flowing gas. Reference numeral 16 denotes a high-pressure pump that brings pure water into a supercritical state. An ash receiving hopper 17 and an ash receiving tank 18 are provided in series at the ash outlet of the partial oxidation reaction tower 13, and valves (not shown) are provided on the supply side and the discharge side of the hopper 17, respectively. Thirteen supercritical states are maintained.

Solid and gas separation filters 11c and 12c are provided on the upper portions of the primary and secondary reaction towers 11 and 12, respectively. These filters 11c and 12c are provided with an average of iron oxide as a main component through a back pressure valve 19a. It is connected to the supply side of an oil reformer 19 filled with sintered particles having a particle size of 3 mm. A fractionating device 20 is connected to the discharge side of the oil reformer 19. The fractionation apparatus 20 includes a heavy oil separator 21, a medium oil separator 22, a light oil separator 23, and a gas-liquid separator 24. These separators 21, 22, 23 and 24 also have a gas cooling function, respectively, and are provided with back pressure valves 21a, 22a, 23a and 24a at the preceding stages, respectively. Separators 21, 22,
A heavy oil receiving tank 21b, a medium oil receiving tank 22b, a light oil receiving tank 23b, and a water receiving tank 24b are provided below 23 and 24, respectively.

In the continuous coal converter constructed as described above, pure water is pumped by the high-pressure pump 16 together with the carbon monoxide generated in the reaction tower 13 to the reaction towers 11 and 12, where the pressure is further increased and the temperature is increased. It becomes supercritical. In these reaction towers 11 and 12, the sintered particles containing iron oxide as a main component are in a supercritical state with an average temperature of 420 ° C. and an average density of 0.5 g / cm ³ using supercritical water and carbon monoxide as flowing gas. Maintained in a fluidized bed. When a finely divided coal is supplied from the coal supply hoppers 11a and 11b by switching a valve (not shown) to the primary reaction tower 11, the above-mentioned reactions (1) to (6) compete with each other and occur in a complex manner. Water in a supercritical state has a greater degree of dissociation into hydrogen ions and hydroxyl ions than ordinary water, so that the hydrolysis reaction of coal is promoted. This hydrolysis is carried out not only for coal but also for heavy liquefied oil as a primary decomposition product. In the water gas shift reaction of the above formula (2), it is said that the activation energy is reduced to about 1/3 of the ordinary energy in high-density water, and therefore the speed of the water gas shift reaction in supercritical water is increased, Active hydrogen (H
It contributes to the promotion of the coal lightening reaction by ₂ ).

The reaction product of the primary reaction tower 11 overflows and is supplied to the secondary reaction tower 12. The liquefied coal in the reaction towers 11 and 12 is heavy oil, medium oil and light oil, and the residual coal that has not been completely liquefied is stored in the residual coal receiving hopper 12a. The valve (not shown) is switched to the partial oxidation reaction tower 13 from the residual coal supply hopper 12b to the reaction tower 1
The residual char (char) produced in Step 2 is supplied. Reaction tower 13
In the above, the fluidized bed is maintained by the flowing gas of high-pressure oxygen in the sintered granules mainly composed of iron oxide,
A supercritical state of 00 ° C. and an average density of 0.42 g / cm ³ is maintained. Due to the supply of the char, a part of the char is oxidized in the reaction tower 13 to generate carbon monoxide as shown in the above formula (1). Also in the reaction of the above-mentioned formula (1), the activation energy is reduced to about 1/3 of the ordinary energy in high-density water, so that the C generated by the thermal decomposition of char is generated.
It also contributes to making O react quickly. The produced carbon monoxide is mixed with supercritical water as described above, and
And 12 as a flowing gas. The ash discharged from the reaction tower 13 is stored in the ash receiving hopper 17. This hopper 17 is supplied with powdered calcium oxide,
Here, the calcium oxide (CaO) reacts with the sulfur in the ash to produce powdered calcium sulfate (CaSO ₄ ), which is collected in the ash receiving tank 18.

The oil generated in the reaction towers 11 and 12 is vaporized in a supercritical state, and is filtered by the filters 11c and 12c and the back pressure valve 1.
The oil is supplied to the oil reformer 19 through 9a. Here, the oil generated in the reaction towers 11 and 12 is further lightened by using the sintered particles in the oil reformer 19 as a catalyst.

In the fractionating apparatus 20, the pressure of the fluid fed from the oil reformer 19 is reduced to a predetermined pressure by the back pressure valve 21a, and the fluid is cooled to a predetermined temperature by the heavy oil separator 21 to remove the heavy oil. It is stored in the high quality oil receiving tank 21b. Next, the fluid pumped from the heavy oil separator 21 is reduced to a predetermined pressure by the back pressure valve 22a, cooled to a predetermined temperature by the medium oil separator 22, and the medium oil is stored in the medium oil receiving tank 22b. . Next, the fluid pumped from the medium oil separator 22 is reduced to a predetermined pressure by the back pressure valve 23a, cooled to a predetermined temperature by the light oil separator 23, and the light oil is stored in the light oil receiving tank 23b. Further, the fluid discharged from the light oil separator 23 is reduced to atmospheric pressure by the back pressure valve 24a, and separated into water and gas (CO ₂ ) by the gas-liquid separator 24. After CO ₂ is discharged to the atmosphere and water is stored in the water receiving tank 24b,
Reused as water for supercritical water.

[0022]

As described above, the present invention has the following excellent effects. (1) Coal can be continuously lightened and liquefied, and heavy oil, medium oil and light oil can be continuously fractionated from the liquefied product. (2) Since active hydrogen required for the hydrogenation reaction is produced using the residue after liquefaction of coal, it is not necessary to supply expensive hydrogen from outside. (3) Compared with the conventional apparatus, the reaction time is extremely short, the conversion efficiency is high, the conversion cost can be reduced, and the conversion amount in a predetermined number of days can be increased without providing a large number of reaction towers and without increasing the size. (4) In the supercritical state, water, gas, converted oil, etc. act in a uniform phase, so that coal can be lightened efficiently. (5) A pretreatment step for removing water is not required, and fractionation of the liquefied oil can be performed only by a reduced pressure operation, so that the distillation and separation step of the liquefied oil is simplified. Therefore, it is simplified as compared with the conventional conversion device.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a continuous coal conversion device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Fluidized bed type reaction tower 11 Primary reaction tower 12 Secondary reaction tower 13 Fluidized bed type partial oxidation reaction tower 17 Ash receiving hopper 19 Oil reformer 20 Fractionation apparatus 21 Heavy oil separator 22 Medium oil separator 23 Light oil separator 24 Gas-liquid separator

Continuing from the front page (72) Inventor Shinichi Hasegawa 1-33 Koishikawa, Bunkyo-ku, Tokyo Mitsubishi Materials Corporation System Business Center (72) Inventor Kenji Nishimura Six-headed Mukoyama, Naka-machi, Naka-machi, Naka-gun, Ibaraki Prefecture 1002 14 Mitsubishi Energy Corporation Naka Energy Research Institute (72) Inventor Hajime Kawasaki 1002 14 Mitsubishi Materials Corporation Naka Energy Research Institute

Claims (8)

[Claims] 1. Carbon monoxide is supplied as a flowing gas together with water in a supercritical state to a fluidizing medium formed therein so as to be maintained in a supercritical state, and pulverized coal is supplied to the fluidizing medium so that the coal is lightened. Fluidized-bed type reaction tower (10), which converts the supercritical water containing oil generated in the reaction tower (10) into a reduced pressure and cooled stepwise to fractionate the generated oil. Equipment (2
0). 2. The continuous coal conversion apparatus according to claim 1, wherein the fluidized medium of the fluidized bed type reaction tower (10) is sintered granules containing iron oxide as a main component and having an average particle size of 0.3 to 5 mm. . 3. An oil filled between a fluidized bed type reaction tower (10) and a fractionating apparatus (20) and containing sintered particles having an average particle diameter of 0.3 to 5 mm and containing iron oxide as a main component. 3. The continuous coal conversion device according to claim 1, further comprising a reformer (19). 4. A fractionator (20) comprising a heavy oil separator (21), a medium oil separator (22), a light oil separator (23), and a gas-liquid separator (24). The oil reformed in the heavy oil separator (19) is the heavy oil separator (21),
4. The continuous coal conversion apparatus according to claim 3, wherein the apparatus is configured to be depressurized and cooled in the order of the medium oil separator (22) and the light oil separator (23). 5. A primary reaction column (11) and a secondary reaction column each having a fluidized bed type reaction column (10) formed so as to be maintained in a supercritical state.
(12), wherein the reaction product of the primary reaction tower (11) is the secondary reaction tower (12)
And carbon monoxide is supplied as a fluid gas together with supercritical water to each fluid medium inside the primary and secondary reaction towers (11, 12). The continuous coal conversion device according to any one of the above. 6. Oxygen is supplied as a flowing gas to an internal fluid medium which can be maintained in a supercritical state, and the residual coal produced in the fluidized bed type reaction tower (10) is supplied to the fluid medium to produce carbon monoxide. And a fluidized bed partial oxidation reaction tower (13) that generates carbon monoxide generated in the partial oxidation reaction tower (13) as a fluidized gas to the reaction tower (10). Item 4. A continuous coal conversion apparatus according to any one of Items 1 to 3. 7. The continuous coal according to claim 6, wherein the fluidized medium of the fluidized-bed partial oxidation reaction tower (13) is a sintered particle mainly composed of iron oxide and having an average particle diameter of 0.3 to 5 mm. Conversion device. 8. An ash receiving hopper (17) for recovering powdery ash generated in a fluidized bed partial oxidation reaction tower (13), wherein calcium oxide is supplied to the ash receiving hopper (17) and The continuous coal conversion apparatus according to claim 6 or 7, wherein the apparatus is configured to generate calcium sulfate from sulfur content of the coal.