JPS62127390A - Method of fluid heat treatment for coal liquefaction residual pitch - Google Patents

Abstract

PURPOSE:To minimize the troubles attributed to the adhesion of pitch, by heating the ground pitch obtd. by grinding a solid coal liquefaction residual pitch in the presence of a granular porous substance and subjecting the heated ground pitch to fluid heat treatment. CONSTITUTION:1pt.wt. solid coal liquefaction residual pitch and 1-4pts.wt. granular porous substance (e.g., coal gasified ash) having a grain size of 5mm or less are fed from a hopper 1 to a double-screw feeder 2 heated by a heater 9' at 300-350 deg.C, thereby effecting grinding and melting of the pitch while causing the pitch to be stuck and adsorbed to the granular porous substance. The non-adhesive grains are fed onto the top of a grating 3' of a fluid oven 3. On the other hand, oxygen is fed from a bomb 4 through a flow meter 5 to a mixer 6, where the oxygen is mixed with the steam fed from a steam generator 7 through an orifice 8 to obtain a mixed gas. The mixed gas heated to 800-1,100 deg.C is fed under the grating 3', thereby fluidizing the non-adhesive grains to attain heat treatment thereof. The temp. within the oven 3 is detected using a thermocouple 10, and the revolution rate of a drive motor 2' for the feeder 2 is controlled through a thermostat 11.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for fluidized heat treatment of coal liquefaction residue pitch, and more particularly to a method for fluidized gasification or fluidized combustion treatment of coal liquefaction residue pitch in a fluidized fluidized furnace.

Coal liquefaction residue pitch is discharged from the vacuum distillation step of the liquefaction product in the coal liquefaction process.

This pitch is useful as a fuel and gasification feedstock, but
Since it is solid at room temperature and is in the form of a block of about 7C11, it cannot be burned or gasified as it is.
It is generally used by granulating it into a pencil shape, pulverizing it, or making it into a slurry. When performing gasification or combustion treatment of such carbon liquefaction residue pitch, it is desirable to use a fluidized bed method to increase treatment efficiency, but pitch tends to stick, so a fluidized bed method is recommended to stably process the pitch. This was extremely difficult.

The present invention provides a method for effectively fluidizing coal liquefaction residue pitch, which is solid at room temperature, while suppressing troubles caused by pitch sticking in a crusher, a feeder, and a fluidized fluidized furnace. That is, according to the present invention, solid coal liquefaction residue pitch is pulverized in the presence of a granular porous material,
Flow of coal liquefaction residue pitch characterized by stirring and mixing the obtained pulverized material at a temperature higher than the softening point of the pitch to adhere the pitch to the granular porous material, which is then introduced into a fluidized bed furnace and subjected to fluidized heat treatment. A heat treatment method is provided.

As the pitch raw material used in the present invention, any coal liquefaction residue pitch can be used as long as it is solid at room temperature.

Such pitch is usually in the form of lumps, and in the present invention, it is first ground into particles of about 10 mm or larger, preferably 5 mm or larger. In this case, grinding must be carried out in the presence of a granular porous material. In the pitch grinding process, the oil contained in the pitch leaches out and the pitch softens due to the heat generated by grinding, which tends to cause seals and blockages in the operating plate, blades, and outlet of the grinder. In the present invention, by adding a granular porous material, the oil is absorbed by the porous material, and the softened pitch is sprinkled with the porous material and does not exhibit stickiness, so that stable pulverization can be performed. can.

As the granular porous material, various organic and inorganic materials can be used as long as they do not melt thermally. From the economic point of view, it is preferable to use coal ash, especially coal gasification.

The porous material used is granular, and the particle size is 5m+
It is preferable to set it to ++ or less, especially 2 mm or less. The granular porous material is preferably used in an amount of 1 to 4 parts by weight, more preferably 2 to 3 parts by weight, per 1 part by weight of coal liquefaction residue pitch. If the amount of porous material is too small, there is a strong possibility that the pitch will develop stickiness, while if it is too large, the processing efficiency of the fluidized heat treatment step will be reduced.

The pulverized mixture obtained as described above is then heated to a temperature above the softening point of pitch, preferably 300 to 350°C, and mixed with stirring. As a result, the molten pitch adheres to and is adsorbed to the porous particles, forming non-adhesive particles. It is preferable to carry out this stirring and mixing using a double screw feeder equipped with a heater, since this allows the raw materials to be fed to the fluidized bed furnace at the same time as the stirring and mixing.

The pitch-adhered porous particles thus obtained are then introduced into a fluidized bed furnace and subjected to a desired heat treatment. For example, using oxygen and water vapor as the fluidizing gas,
Gasification is carried out at 0°C, especially 900-1100°C, or combustion treatment is carried out at 700-1100°C, especially 900-1100°C, using air as the fluidizing gas.

The method of the present invention provides the following effects.

(1) Since porous particles such as coal ash are mixed in the process of pulverizing coal liquefaction residue pitch, it can be easily pulverized without pitch or oil adhering to the pulverizer.

(2) The double-screw feeder is heated to melt the coal liquefaction residue pitch, which attaches to and adsorbs onto porous particles such as coal ash, and supplies the raw material to the fluidized fluidized furnace without clogging the inside of the double-screw feeder. can be supplied.

(3) The adhered particles supplied into the fluidized fluidized furnace have a smooth particle property, so the particles do not adhere to each other and are fluidized well, so there is no explosion due to stairwell etc.
! It can be operated completely safely even in gasification treatment using raw materials.

(4) Since the R1 particles have smooth fluidity, they can be fed from the bottom of the fluidized bed, so local combustion at the top of the bed will not occur and the temperature distribution in the furnace can be maintained uniformly. , it is possible to scale up the table.

Example 1 2.5 parts by weight of coal gasification particles with a particle size of 1.68 mm or less and a scraping density of 0.40 g/cc were mixed with 1 part by weight of coal liquefaction residue pitch, and pulverized to 5IIIn+ or less. .

As a result, the grinder can be easily ground even during long-term operation without oil or pitch adhering to the grinder. Then the first
The particles were put into the double screw feeder of the fluidized fluidized furnace shown in the figure, and the double screw feeder was heated at 300°C to 30°C.
It was heated to 50°C and supplied to a fluidized fluidized furnace. The pitch crushed to 5+W or less was melted in the double screw feeder and adhered to and adsorbed to the coal gasification particles that were being fed together, becoming non-adhesive particles and being fed into the fluidized bed furnace.

Coal liquefaction residue pitch has an ash content of approximately 10% and an unburned content of approximately 90%.
%, and the coal gasification particles contained about 80% ash and about 20% unburned matter. Table 1 shows the properties of the coal liquefaction residue pitch and the properties of the adhering particles obtained by adhering the pitch to the coal gasification particles.

Table 1 Elemental analysis value of liquefied residue pitch, elemental analysis value of calorific value adhered particles, industrial analysis value of calorific value adhered particles.The bulk density of the adhered particles was 0.53 g/cc, which was the same as that of the original coal gasification particles. It can be seen that the pitch is larger than 0.40 g/cc, and the weight is increased due to the adhesion and adsorption of pitch. Next, Fig. 2 shows the particle size distribution and average particle size of the adhered particles and the original coal gasification particles. The attached particles have a larger particle size than the coal gas chemical particles, less than 4.0 mm, and the average particle size is also 0.52 mm compared to the coal gas chemical particles.
It can be clearly seen that the particle size increases from + to 0.65 mm, and the pitch is attached and the particle size is increased.

A gasification reaction experiment was carried out on the adhered particles having the properties described above using oxygen and water vapor using a flow apparatus shown in FIG. That is, first, the coal gasification particles mixed with the crushed coal liquefaction residue pitch enter the hopper 1 and pass through the heater 9.
As mentioned above, the pitch adheres to the coal gas conversion particles by the double screw feeder 2 heated by 1, becomes adsorbed, becomes smooth and fluid particles, and is fed directly above the 11 plates 3' of the fluidized bed furnace 3. be done. The fluidized fluid furnace 3 has an inner diameter of 108 mm, a total length of 1 m, and a perforated plate 3' with an opening ratio of 2% and a hole diameter of 2.
mm was used. Oxygen is J from oxygen cylinder 1
It enters the mixer 6 via the ε spacer 5. Steam enters the mixer 6 from the steam generator 7 through the orifice 8, where it is mixed with oxygen and blown under the perforated plate of the fluidized bed, where it adheres to the pitch on the perforated plate and fluidizes and reacts the adhering particles. For startup, the attached particles are ignited by the external heat heater 9 and the temperature is raised to a predetermined temperature, and then the external heater is turned off and the temperature is raised to the set temperature by combustion heat of oxygen and the attached particles, so-called self-combustion. When the fluidized furnace temperature reaches the set temperature, the thermocouple 10 detects the furnace temperature, and the temperature controller 1
1, the rotational speed of the drive motor 2' of the double screw feeder 2 is controlled to increase or decrease the amount of attached particles to be supplied, that is, a method that utilizes the cooling effect of the sensible heat necessary to heat the attached particles to be supplied. The internal temperature was controlled. By this method, the temperature inside the furnace could be controlled within ±5°C. In the first country, 12 is an overflow receiver, 13 is a collector, 14 is a gas discharge pipe, and 15 is a gas sampling port.

By the above method, the above-mentioned adhered particles were removed at an in-furnace flow rate of 57 am/
Fig. 3 shows the results of a gasification experiment when the oxygen concentration was varied from 21% to about 32% with the gasification reaction temperature constant at 5 ec and 1000°C. From FIG. 3, as the oxygen concentration increases, CO2 decreases, CO increases, and the crude gas calorific value gradually increases. Table 2 shows the gas analysis values when the oxygen concentration was 31.7%.

Table 2 From Table 2, oxygen concentration is close to 32% (CO is 44%, H2
is 34%, and the calories of crude gas are 2540 cal/
Nrn', medium calorie gas can be obtained, and it can be used for many purposes. In the fluidized bed reactor, the coal liquefaction residue pitch attached to and adsorbed on the coal gasification particles is gasified, and the coal gasification particles enter the overflow receiver and are taken out, where they are mixed with the liquefaction residue pitch again and regenerated as described above. It can be used as

Example 2 Using the same method as in Example 1, the flow rate in the furnace was constant at 57 cm/5ee, the oxygen concentration was constant at 25.2%, and the temperature in the furnace was 950°C.
.

Figure 4 shows the results of gasification experiments when the temperature was changed to 1000°C and 1050°C. CO2 increases as the temperature inside the furnace increases, indicating that the combustion reaction is progressing. The temperature inside the furnace is raised by letting the attached particles grow, so when the oxygen concentration is constant, the amount of heat generated decreases as the furnace temperature rises. Table 3 shows industrial analysis values for overflow particles and dust collector dust when the furnace temperature was 1050°C.

Table 3 Table 3 shows that most of the overflow particles discharged from the overflow receiver have been ashed and are in a state close to fluidized combustion. When fluidizing and burning these adhered particles, oxygen and water vapor may not be used, but air may be used using an air blower 16 as shown in FIG. Since the dust collector dust has a large amount of unburned matter, it is returned to the hopper and sent to the fluidized bed furnace again.The overflow particles are the original coal gasification ash particles and have almost no unburned matter, so they are mixed with the coal liquefaction residue pitch and recycled again. Make use of it. FIG. 5 shows a temperature chart in this experiment. The adhered particles were smooth. 1 has a dynamic property, and since it is supplied onto the perforated plate of the fluidized bed furnace, it has a good fluidity, and the temperature inside the furnace is ±5℃.
It can be seen that it is controlled within The temperature inside the furnace can be easily raised, the fluidized fluidized furnace can be operated completely stably and safely, and the furnace can be scaled up.

As described above, coal gasification ash particles, which are the waste products of coal gasification, and pitch, which is the residue of coal liquefaction, are mixed to form particles that can be fluidized, stably and safely using such a simple method. Gas and heat can be obtained.

[Brief explanation of drawings]

Figure 1 is a flow sheet of an apparatus implementing the present invention, and Figure 2 is a comparison of the particle size distribution and average particle size of coal gasification ash particles and coal gasification ash particles to which coal liquefaction residue pitch has been attached and adsorbed. Figure 3 is a graph showing the change in the generated gas when adhering particles are gasified by changing the oxygen concentration while keeping the furnace temperature constant. FIG. 5 is a graph showing changes in the generated gas when adhering particles are gasified, and FIG. 5 is a temperature chart of the fluidized bed furnace when the present invention is carried out. In the figure, l is a supply hopper, 2 is a double-screw feeder, 2' is a drive motor for the double-screw feeder, 3 is a fluidized flow furnace, 3' is its perforated plate, 4 is an oxygen cylinder, 5 is a flow meter, 6 is a gas mixer, 7 is a steam generator, 8 is an orifice, 9 is a heater for ignition, 9' is a heater that heats the double screw feeder, 10 is a thermocouple that detects the temperature inside the furnace, 11 is inside the furnace In order to keep the temperature constant, there is a controller that controls the rotational speed of the drive motor of the double screw feeder and adjusts the supply of adhering particles; 12 is an overflow receiver; 13 is a dust collector; 14 is a gas A discharge pipe, 15 is a gas sampling port, and 16 is an air blower for fluidized combustion. Patent applicant: Director of the Agency of Industrial Science and Technology, etc. Designated agent: Director of the Hokkaido Industrial Development Testing Institute, Agency of Industrial Science and Technology, Goto, Abe, J.K., Cmm)

Claims (1)

[Claims] (1) Pulverize solid coal liquefaction residue pitch in the presence of a granular porous material, stir and mix the resulting pulverized product at a temperature above the softening point of the pitch to adhere the pitch to the granular porous material, and then A method for fluid heat treatment of coal liquefaction residue pitch, which is characterized by introducing the pitch into a fluidized fluid furnace and subjecting it to fluid heat treatment.