JPH03215594A - Pyrolysis of coal - Google Patents

Abstract

PURPOSE:To prepare a fine powder char in a stabilized fluidized heating oven and to regulate efficiently a pyrolyzed gas compsn. by feeding a fine powder coal into a heating oven wherein a fluidized layer is formed of catalyst particles with a specified size and pyrolyzing the coal. CONSTITUTION:A fluidized layer (a fluidized bed) is formed by fluidizing catalyst particles 3 placed on a grating (a hot plate) 2 of a fluidized heating oven 1 by means of a flowing gas fed from a gas feeding apparatus 5 from the lower part 4 of the heating oven. A heating apparatus 6 is provided on the outer periphery of the heating oven 1 to heat the oven and the catalyst particles at a specified temp. The coal is uniformly dispersed by vigorous flowing in the fluidized layer and is brought into collision and contact with the surfaces of the catalyst particles and a part thereof is adhered to the surfaces of the catalyst particles. As the result, it is decomposed by heating. As the coal is finely powdered, the pyrolysis proceeds rapidly. The coal is mainly converted into a char by pyrolysis, ascends in the heating oven 1, is discharged with the gas from the upper part of the heating oven, and is finally separated and collected in a particle collector 8. A catalyst particle 3 with a particle size of about 10mm or smaller is used.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to thermal decomposition of coal.

(Prior art) Conventional methods for thermally decomposing coal include heating a packed bed of coal or heating a mixed fluidized bed of sand and coal. If changes are made, they are done using a subsequent secondary decomposition device.

(Intelligence B to be Solved by the Invention) Coal pyrolysis particles mainly become char, and when this char is used as a fuel or carbon source, it may be advantageous to form it into a fine powder.

To make pulverized char in a heating furnace, pulverized coal must be supplied, but if only pulverized coal is supplied and a fluidized bed is created, unreacted coal powder will rise inside the furnace and be discharged. Sometimes it happens.

Further, in order to adjust the composition of the decomposed gas, it is necessary to install a subsequent secondary decomposition device as described above.

The purpose of the present invention is to produce fine powder char in a stable fluidized heating furnace and to efficiently control the cracked gas composition. (Means for Solving the Problems) The present invention involves flowing catalyst particles having a particle size of 10 mm or less, preferably about 1 mm or less, on a perforated plate (furnace plate) of a heating furnace, Further heating is performed, and fine powder coal of a size in which the final velocity of thermally decomposed char is lower than the terminal velocity of the catalyst particles is supplied into this fluidized and heated catalyst particle bed, and by uniformly dispersing it, it is distributed on the surface of the catalyst particles. The above objective is achieved by adhering, bringing into contact, and causing a rapid thermal decomposition reaction.

By supplying pulverized coal into a fluidized bed formed by catalyst particles of the above-mentioned size and scattering it therein, residence time is maintained for a predetermined time, and the surface of the heated catalytic particles Efficient thermal decomposition is achieved by adhesion and contact.

The decomposed coal particles mainly become char, but since the apparent density decreases and the terminal velocity of pulverized coal is smaller than that of the catalyst particles, only the char leaves the catalyst particle layer and rises together with the decomposition gas. The particles (char) discharged from the furnace are collected by an attached solid particle collection device, and the gas is separated into a liquid component and a gaseous component by a cooling device, and each component is collected.

In addition, the present invention adjusts the thermal decomposition conditions of coal by selectively using calcium carbonate, silica, alumina, etc. as materials for catalyst particles that have a catalytic effect, changes the composition of the decomposition gas, and changes the composition of the liquid product. The desired product is obtained by varying the yield.

(Example) Fig. 1 schematically shows the equipment for carrying out the method of the present invention, in which medium particles 3 placed on a perforated plate (furnace plate) 2 of a fluidized fluidized heating furnace 1 are By supplying the fluidized gas from the device 5 from the lower part 4 of the heating furnace, it is fluidized to form a fluidized bed. A heating device 6 is installed on the outer periphery of the heating furnace 1.
is provided to heat the furnace and catalyst particles to a predetermined temperature. The heating of this fluidized bed is not from the outer periphery of the heating furnace;
This may also be done by heating the flowing gas.

Further, the fluidizing gas supply amount is adjusted to such an extent that the catalyst particles are sufficiently fluidized and only the pulverized coal whose terminal velocity is smaller than that of the catalyst particles rises in the furnace.

Finely powdered coal is supplied from a coal supply device 7 into a fluidized bed of catalyst particles. The coal is uniformly dispersed by the violent flow phenomenon in the fluidized bed, collides with and contacts the surface of the catalyst particles, and some of the coal adheres to the surface of the catalyst particles and is heated and decomposed. Since coal is a fine powder, thermal decomposition proceeds rapidly.

Coal is thermally decomposed and mainly becomes char, but the apparent density of the particles (char) is about 1/2, and the sliding friction resistance of the particles is also reduced, so it can be removed from the fluidized bed by riding the decomposition product gas flow. The particles are separated, ascend inside the heating furnace 1, are discharged from the upper part of the heating furnace together with the gas, and are separated and collected by an attached particle collection device 8, for example, a cyclone separator.

The gas is brought to a gas cooling device 9 and cooled there. As a result, the liquid component is separated and stored in the liquid component collection tank 10, and the gaseous component is collected by the particle collection tank 11.

FIG. 2 illustrates the effect of the type of catalyst particles on the yield of light liquid hydrocarbons. The coal is lignite, the heating temperature is 800°C, and helium gas is used as the fluidizing gas.

FIG. 3 illustrates the effect on the yield of CI C3 hydrocarbon gas under the same conditions.

The yield of gaseous products varies significantly depending on the type of catalyst particles. Further, the light liquid hydrocarbon yield is higher in the order of calcium carbonate (Cab), alumina, and silica, and in particular, in the case of calcium carbonate, it is about 176 compared to silica B.

(Effects of the Invention) As described above, according to the present invention, it is possible to thermally decompose pulverized coal efficiently, produce pulverized uncharred powder, and improve the composition of decomposed gas and the yield of liquid products. Can be easily changed upon request.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of the equipment for carrying out the method of the present invention, Figure 2 is a graph illustrating the difference in the yield of light liquid hydrocarbons depending on the type of catalyst particles, and Figure 3 is a graph showing the difference in yield of light liquid hydrocarbons depending on the type of catalyst particles. ．． -C■ is a graph illustrating the difference in the yield of hydrocarbon gas. ■... Fluidized heating furnace, 2... Perforated plate, 3... Catalyst particles, 4... Lower part of heating furnace, 5... Gas supply device, 6...
- Heating device, 7... Coal supply device, 8... Particle collection device, 9... Gas cooling device, 10... Liquid fraction recovery device, 11... Particle collection device.

Claims (1)

[Claims] 1. The particle size is about 10 mm or less, preferably 1 mm.
Pulverized coal of a size in which the terminal velocity of thermal decomposition char is lower than the terminal velocity of the catalyst particles is supplied into a heating furnace in which a fluidized bed is created by catalyst particles of about 100 mL or smaller in size, and the coal is allowed to adhere to and contact with the surface of the catalyst particles. A coal pyrolysis method characterized by thermally decomposing coal. 2. The pyrolyzed particles are lifted up on cracked gas, discharged from the upper part of the heating furnace, and collected by an attached particle collection device, and the cracked gas is also collected by a subsequent gas collection device. Method. 3. Coal thermal decomposition conditions can be adjusted by selectively using various metals, their oxides, their salts, or mixtures thereof as catalyst particles forming a fluidized bed in the heating furnace. 3. The method according to claim 1, wherein the composition of the pyrolysis gas is changed.