JP2002275478A - Method for coal liquefaction - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the liquefaction ratio of coal by supercritical water. SOLUTION: Coal 27 and an impact body 23 are thrown into an inner vessel 21 of a pressure reactor 1 and the coal is brought into contact with supercritical water or subcritical water, reacted and liquefied while being crushed by the impact body 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for liquefying coal using supercritical water technology.

[0002]

2. Description of the Related Art Conventionally, as a method of liquefying coal using supercritical water technology, a slurry is prepared by mixing finely divided coal, water and formic acid, and the slurry is maintained in a supercritical state. Various methods have been reported, for example, in which formic acid is decomposed and active hydrogen generated by this decomposition reaction is reacted with coal to lighten and liquefy (for example, Japanese Patent Application Laid-Open No. 10-237456).

[0003] However, the liquefaction rate of each of them is low, and they have not yet been put to practical use. For this reason, the use of a catalyst or the like has been studied, but the liquefaction rate cannot be significantly improved.

[0004]

In the liquefaction technology of coal utilizing supercritical water technology, one of the causes of the low liquefaction rate of coal is that the surface of the coal becomes inactive during supercritical water treatment. For this reason, there are not a few that remain as residues without being decomposed. Therefore, it is considered that if the inactivation of the coal surface in such supercritical water can be prevented, the decomposition / liquefaction reaction is promoted and the liquefaction rate can be improved.

The present invention has been made in view of such a point, and since the surface of the coal is deactivated by the supercritical water treatment, the liquefaction rate of the coal is reduced by creating an active surface in the supercritical water. An object of the present invention is to provide a coal liquefaction method that can be improved.

[0006]

In order to achieve the above object, a method for liquefying coal according to the first aspect of the present invention comprises crushing coal while contacting and reacting with supercritical water or subcritical water. It is characterized by the following.

In the present invention, when contacting and reacting coal with supercritical water or subcritical water, the coal is reacted while being pulverized. By such pulverization, an active surface appears on the coal one after another, and reacts with supercritical water or subcritical water. Therefore, liquefaction is promoted, and the liquefaction rate is improved.

In the present invention, as described in claim 2, the reaction temperature is 200 ° C. to 850 ° C., and the reaction pressure is
It is preferable that the pressure be 2 Mpa to 100 Mpa.

[0009] Examples of the above-mentioned coal include lignite, lignite, bituminous coal and anthracite.

[0010]

Embodiments of the present invention will be described below.

The supercritical water used in the present invention is a non-condensable high-density water exceeding a critical temperature (374 ° C.) and a critical pressure (22.1 MPa). In the present invention, subcritical water may be used instead of supercritical water.

In the present invention, when the coal is brought into contact with and reacted with supercritical water or subcritical water, the coal is reacted while being pulverized. The reaction temperature and reaction pressure at this time are preferably adjusted in the range of 200 ° C. to 850 ° C. and 2 MPa to 100 MPa, respectively. If any one of the temperature and the pressure is lower than the above ranges, the liquefaction of the coal does not proceed efficiently, and the liquefaction rate decreases. Conversely, if either one of the temperature and the pressure is higher than the above range, not only does the load on the apparatus increase, but also when a permanent magnet as described below is used as the crushing means, the permanent magnet does not function and crushing can be performed. And it becomes difficult to improve the liquefaction rate.
A more preferred range is a reaction temperature of 300 ° C to 750 ° C, a reaction pressure of 5 MPa to 80 MPa, and a reaction temperature of 300 ° C to 600 ° C.
C. and the reaction pressure are more preferably in the range of 10 MPa to 60 MPa.

In carrying out the present invention, for example, the following apparatus can be used.

That is, FIG. 1 schematically shows an example of a coal liquefaction apparatus used in the present invention, and FIG.
The main part is shown enlarged.

As shown in these figures, this apparatus comprises a pressure-resistant reaction vessel 1 having an electric furnace 1a, a solvent tank 2 containing pure water, and pure water from the solvent tank 2 to the pressure-resistant reaction vessel 1. A pump 3 for feeding in, a preheater 4 for preheating the pure water to be fed in, a water cooling pipe 5 for water-cooling a gas component discharged from the pressure-resistant reaction vessel 1, and a drain tank for collecting a liquid condensed by water cooling 6 and a pipe 7 for connecting these devices. A line heater 8 is provided in a pipe 7 connecting the preheater 4 and the pressure-resistant reaction vessel 1.
Is attached. In FIG. 1, reference numeral 9 denotes a flow meter inserted into a pipe 7 connecting the pump 3 and the pressure-resistant reaction vessel 1,
Reference numeral 10 denotes a thermocouple for measuring temperature in the pressure-resistant reaction vessel 1, 11 denotes a thermocouple for temperature control, and 12 denotes a pressure inserted between the pressure-resistant reaction vessel 1 and the water cooler 5. Total, 1
Reference numeral 3 denotes a pressure reducing valve interposed between the water cooling pipe 5 and the drain tank 6, respectively.

As shown in FIG. 2, the pressure-resistant reaction vessel 1 comprises a reaction vessel body 20, an inner container 21 inserted in the reaction vessel body 20, and a lid 22 for hermetically sealing the upper openings thereof. And Further, as a pulverizing mechanism for pulverizing the object to be treated put into the inner container 21, an impact body 23 made of a permanent magnet whose surface is covered with stainless steel or the like, which is accommodated in the inner container 21, Electromagnetic coils 24 and 25 are provided at the bottom and above the lid 22 and configured to move the impactor 23 up and down by changing the direction of the current. Reference numeral 26 denotes a filter attached to the opening of the pipe 7 to prevent the pulverized object from flowing out.

In such an apparatus, first, coal 27 and impact body 23 are charged into inner container 21 of pressure-resistant reaction vessel 1. The shape of the coal 27 is not particularly limited, such as a lump or a powder. Next, the pure water heated by the preheater 4 and the line heater 8 is continuously supplied from the solvent tank 2 and the pressure-resistant reaction vessel 1 is heated to set the inside of the inner container 21 to the temperature and pressure range as described above. ,
Further, energization of the electromagnetic coils 24 and 25 is started. The coal 27 accommodated in the inner container 21 comes into contact with water in a supercritical state or a subcritical state while being pulverized by the impactor 23, and is efficiently decomposed. Thereafter, the electromagnetic coil 24,
While stopping the power supply to 25, the inside of the inner container 21 is returned to normal temperature and normal pressure, and the decomposition products are collected. A part of the decomposition product is discharged from the pressure-resistant reaction vessel 1 through the pipe 7 together with the water in the supercritical state or the subcritical state, cooled by the water cooling pipe 5, returned to normal temperature and normal pressure, and collected in the drain tank 6. Is done.

In such a method, since active surfaces appear one after another on the coal 27 by pulverization and react with supercritical water or subcritical water, the decomposition of the coal 27 is promoted, and the coal is liquefied at a high liquefaction rate. Can be liquefied.

In the present invention, after charging the coal 27 and the impacting body 23 into the pressure reaction vessel 1, the inside of the system is once filled with pure water to remove the oxygen inside, and then the heating and pressurization is started. It is desirable to do so. by this,
Reactions other than the decomposition reaction such as oxidation of the surface of the coal 27 can be suppressed, and the liquefaction rate can be further improved.
In addition, from the same viewpoint, it is desirable to use water from which dissolved oxygen has been removed by performing bubbling treatment with nitrogen gas or the like as water used for decomposition.

The present invention can be carried out using a batch-type or continuous-reaction-type apparatus instead of the above-mentioned semi-batch-type apparatus. Further, in the above example, the coal is pulverized by a pulverizing mechanism using an electromagnetic coil. However, as long as pulverization can be performed in supercritical water or subcritical water, such a material is used. It is not limited.

The present invention can be widely applied to the liquefaction of various types of coal such as lignite, lignite, bituminous coal, anthracite, etc. Particularly useful when applied to bituminous coal.

[0022]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

EXAMPLE Using the apparatus shown in FIG. 1, a liquefaction experiment of coal (brown coal) was performed.

That is, in a pressure-resistant reaction vessel 1 (inner diameter: 20 mm, height: 100 mm, volume: about 30 cc), about 5 g of a lump of coal,
Impact body (diameter 10mm, length 50mm) made of permanent magnet (ferrite magnet) whose surface is coated with stainless steel (SUS316)
23 were introduced. Next, after the inside of the system is filled with degassed pure water, the flow rate of the pure water is set to 0.1 ml / min, and the pressure in the system is adjusted to a pressure regulator at the outlet of the pressure-resistant reaction vessel 1 (not shown).
Was set to 40MPa. Thereafter, the temperature inside the reaction vessel 1 was raised to 390 ° C. over about 40 minutes. When the temperature in the reaction vessel 1 reached 390 ° C., the electromagnetic coils 24 and 25 were energized, and the flow rate of pure water was changed to 5 ml / min. Electromagnetic coil 2
Simultaneously with the energization of 4, 25, the vertical movement of the impact body 23 started, and comminution of the lump of coal started. After continuing pulverization for 5 minutes, the energization of the electromagnetic coils 24 and 25 was stopped, the flow rate of pure water was returned to 0.1 ml / min, and cooling was performed over about 2 hours to return to normal temperature and normal pressure. The liquid in 1 and the liquid discharged out of the system during the reaction were recovered.

The collected liquid is evacuated at 100 ° C. for 5 hours (10 mm
(Hg or less)), dried, weighed and the liquefaction ratio was calculated to be about 80%.

COMPARATIVE EXAMPLE 1 As the coal to be charged into the pressure-resistant reaction vessel 1, powdered coal (average particle size: about 0.1 mm) which has been pulverized in advance is used. Coil 24,
The coal liquefaction process was performed in the same manner as in the above example except that the power was not supplied to
The liquid substance inside and the liquid substance discharged out of the system during the reaction were recovered.

The collected liquid was dried under vacuum under the same conditions as in the above example, and the weight was measured to calculate the liquefaction. The result was about 50%.

Comparative Example 2 The procedure of Comparative Example 1 was repeated, except that the same lump of coal as in the example was directly charged into the pressure-resistant reactor 1.
The coal was liquefied, and the liquid in the pressure-resistant reactor 1 and the liquid discharged out of the system during the reaction were recovered.

The collected liquid was dried under vacuum under the same conditions as in the above example, and the weight was measured to calculate the liquefaction. The result was about 45%.

Comparative Example 3 Coal liquefaction was performed in the same manner as in Comparative Example 1 except that about 1 g of formic acid was charged into the pressure-resistant reaction vessel 1 together with the powdered coal. The liquid and the liquid discharged out of the system during the reaction were recovered.

The recovered liquid was dried under vacuum under the same conditions as in the above example, and the weight was measured to calculate the liquefaction. The result was about 55%.

[0032] Comparative Example 4 powdery Co-Mo oxide based catalyst with coal (MoO ₂
And CoO supported on alumina), and liquefaction of coal was performed in the same manner as in Comparative Example 1 except that about 1 g was charged into the pressure-resistant reaction vessel 1. In addition, the liquid discharged out of the system during the reaction was recovered.

The recovered liquid was dried under vacuum under the same conditions as in the above example, and the weight was measured to calculate the liquefaction rate. The result was about 55%.

[0034]

As described above, according to the present invention,
Since the liquefaction treatment is performed while pulverizing the coal in supercritical water or subcritical water, the liquefaction rate of the coal can be greatly improved.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing an example of a coal liquefaction apparatus used for carrying out the present invention.

FIG. 2 is an enlarged sectional view showing a main part of the apparatus shown in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Pressure-resistant reaction container 2 ... Solvent tank 20 ... Reaction container main body 21 ... Inner container 22 ... Lid 23 ... Impact body 24, 25 ... Electromagnetic coil

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kiyoshi Furumura 20-1 Kitakanyama, Odaka-cho, Midori-ku, Nagoya-shi, Aichi Prefecture Inside the Electric Power Research Laboratory, Chubu Electric Power Co., Inc. (72) Susumu Hirai, Susumu Hirai, Kawasaki, Kawasaki, Kanagawa Prefecture Inside Showa Electric Wire & Cable Co., Ltd. 2-1-1 Oda Sakae-ku (72) Inventor Hiroaki Morita Inside 1-1 Showa Electric Wire & Cable Co., Ltd. 2-1-1 Oda Sakae, Kawasaki-ku, Kawasaki City, Kanagawa Prefecture

Claims (3)

[Claims] 1. A method of liquefying coal, comprising crushing coal and contacting and reacting with supercritical water or subcritical water to liquefy the coal. 2. The method according to claim 1, wherein the reaction temperature is 200 ° C. to 850 ° C. and the reaction pressure is 2 Mpa to 100 Mpa.
A liquefaction method for coal as described in the above. 3. The method according to claim 1, wherein the coal is at least one selected from the group consisting of lignite, lignite, bituminous coal and anthracite.