JP2853916B2 - Apparatus and method for rapid pyrolysis of coal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a chemical raw material, a fuel gas and a carbonaceous raw material from coal, in which a coal and a high-temperature gas are mixed to perform a thermal decomposition reaction of the coal. And methods.

[0002]

2. Description of the Related Art One of coal processing processes is a coal pyrolysis process. Pyrolysis (dry distillation) of coal produces high calorific value gas, tar and coke. These are used as fuels, chemical raw materials, and reducing materials for metal refining. It is well known that the rapid pyrolysis reaction of coal increases the yield of gas-liquid components such as gas and tar as compared with the pyrolysis reaction in a conventional coke oven.
Therefore, when it is desired to recover a large amount of gas-liquid components from coal, a rapid pyrolysis method of coal is preferable.

[0003] As a method frequently used as a rapid pyrolysis process of coal, there is a method using a gas-bed reactor. In this method, coal and high-temperature gas are blown into the reactor, where they are mixed and thermally decomposed. In order to efficiently perform pyrolysis of coal by this structure, coal particles are widely dispersed in the gas phase, the mixture of coal particles and high-temperature gas is uniform, and there is no adhesion or growth of coal on the inner wall of the reactor It is necessary.

[0004] As a prior art of a reactor for rapid pyrolysis of coal, there is, for example, an apparatus disclosed in Japanese Patent Application Laid-Open No. Hei 2-265959. FIG. 2 shows an example of a reactor using the same apparatus. Coal is blown into the reactor from a coal inlet pipe 1 in the upper part of the reactor, and high-temperature gas is blown from a nozzle 5 around an outlet of the coal inlet pipe, where the coal and gas are mixed and a thermal decomposition reaction occurs. It has become.

[0005]

However, when thermoplastic coal is used in the reactor of the above-described apparatus, the coal adheres to and grows on the inner wall of the reactor, and the thermal decomposition reaction of the coal is inhibited. Good quality gas by rapid pyrolysis of coal,
It is well known that coal having thermoplasticity is preferable in order to obtain a large amount of gas-liquid components such as tar.

An object of the present invention is to prevent the adhesion and growth of coal on the inner wall of a reactor, thereby making it possible to use a wide range of coal including thermoplastic coal and efficiently remove gas and liquid components such as high-quality gas and tar. It is an object of the present invention to provide an apparatus and a method for rapid pyrolysis of coal which are well produced and have less restrictions on raw coal.

[0007]

SUMMARY OF THE INVENTION In order to achieve the object, the present invention provides a coal pyrolysis apparatus comprising a coal inlet pipe, a gas inlet, a gas injection nozzle and a reactor. Coal characterized in that two gas injection nozzles are provided, a first system is provided with a high-temperature gas injection for thermal decomposition of coal, and a second system is provided with a gas injection for preventing coal adhesion on the inner wall of the reactor. It is a pyrolysis device. Further, in the present invention, there is provided a coal pyrolysis method characterized in that the gas blown from the second system contains a gas having high reactivity with coal char.

Hereinafter, the present invention will be described in detail. FIG. 1 shows a conceptual diagram of a coal pyrolysis apparatus according to the present invention. In this apparatus, coal fed by airflow through a pipe 1 and, in a first gas blowing apparatus, gas is sent from a pipe 3 to an upper part 4 of the apparatus, and is blown into a reactor 2 from a nozzle 5, and the high-temperature gas and the reactor 2 In the second gas blowing device, gas is sent from a pipe 6 to a peripheral portion 7 of the reactor, and is blown from a nozzle 8 into the inner wall portion of the reactor. Has a structure to prevent coal adhesion and growth. The function of the gas injection device of the second system is to inject the gas in the opposite direction to the direction in which the coal particles injected into the reactor are directed toward the reactor wall, and to prevent the coal particles from approaching the reactor inner wall. I have.

In the gas injection device of the second system, the arrangement of the gas injection nozzles 8 in the reactor need not necessarily be arranged on all the reactor walls. Coal deposition on the reactor inner wall occurs when the coal contacts the reactor inner wall at a temperature at which the coal is thermoplastic. Generally, the temperature at which coal exhibits thermoplasticity is 200
~ 600 ° C. Therefore, it is necessary to arrange the gas injection nozzle 8 on the inner wall of the reactor at least in a region near the inner wall of the reactor where the temperature of the coal particles becomes thermoplastic.

[0010] Further, it is preferable that the gas blown from the gas blowing device of the second system contains a component highly reactive with coal char, for example, one or several oxidizing gases such as steam, carbon dioxide and oxygen gas. The function is to oxidize the coal char adhered to the inner wall of the reactor at an early stage to prevent the growth of the coal char on the inner wall of the reactor. The oxidizing component in the blown gas reacts with the coal char at the inner wall of the reactor and changes into H ₂ and CO gas, so that the quality of the product gas does not deteriorate.

As described above, in the coal pyrolysis apparatus, a device for ejecting gas from the peripheral portion of the inner wall of the reactor is provided, and the gas blown from the device contains an oxidizing gas which easily reacts with coal char. It prevents coal char from adhering and growing on the inner wall of the vessel and plays a major role in stable coal pyrolysis operation, securing high-quality products, and using a wide range of raw coal.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment using the apparatus and method of the present invention will be described below.

Table 1 shows the properties of the coal used. Here, the A coal is a small thermoplastic coal. On the other hand, B coal is a highly thermoplastic coal.

Crush the coal of Table 1 to <200 mesh
Thermal decomposition was performed under the conditions of a supply amount of 240 g / hr and a reaction temperature of 900 ° C. As a gas used in this example, a heated N ₂ gas was used as a coal heating gas (first system). Further, as a gas (second system) ejected from the inner wall of the reactor, a gas obtained by mixing 20% of air with N ₂ gas was used. The reactor had an inner diameter of 55 mm and a length of 600 mm, and a gas blowing nozzle arranged around the inner wall of the reactor was provided in the upper half of the inner wall of the reactor. The nozzle diameter is 0.5mm

[0015]

[Table 1]

The nozzle density was 1 nozzle / cm ² . The gas flow rate from the first system for heating coal was 15 Nl / min, and the gas flow rate from the second system for preventing coal adhesion on the inner wall surface of the reactor was 2 Nl / min. Table 2 shows the results.

[0017]

[Table 2]

In the case of the comparative example, the second
Except for the gas blowing device of the system, other test conditions are the same as those of the embodiment. Table 3 shows the results of the comparative example.

[0019]

[Table 3]

[0020]

As described above, according to the present invention, even when coal having thermoplasticity is used, a stable pyrolysis operation can be performed and a product of good quality can be obtained. In other words, the present invention stabilizes the coal pyrolysis operation by preventing coal adhesion and prevention on the inner wall of the reactor during the pyrolysis of the coal, securing high-quality products and restricting the use of raw coal. It is made possible and has great industrial and economic effects.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an example of an apparatus of the present invention.

FIG. 2 is a conceptual diagram showing an example of a conventional device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Coal introduction pipe 2 ... Pyrolysis reactor 3 ... 1st system gas introduction pipe 4 ... 1st system gas introduction part 5 ... 1st system gas introduction nozzle 6 ... 2nd system gas introduction pipe 7 ... 2nd system gas introduction Part 8: second system gas introduction nozzle

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C10J 3/74 C10J 3/74

Claims (2)

(57) [Claims] An apparatus for thermally decomposing coal by bringing coal into contact with a high-temperature gas in a reaction vessel having a coal introduction pipe, a high-temperature gas introduction section, and a gas injection nozzle, wherein the high-temperature gas introduction section and the gas injection nozzle have two systems. The first system is provided as a supply source of a high-temperature gas for thermal decomposition of coal, and the injection nozzle of the second system is provided on a surface of the inner wall surface of the reaction vessel where the coal contacts,
An apparatus for rapid pyrolysis of coal, wherein the second system functions as means for preventing coal adhesion to the inner wall surface of the reaction vessel. 2. A method for thermally decomposing coal by bringing coal into contact with a high-temperature gas in a reaction vessel having a coal introduction pipe, a high-temperature gas introduction section, and a gas injection nozzle. The first system is provided as a supply source of a high-temperature gas for thermal decomposition of coal, and the injection nozzle of the second system is provided on a surface of the inner wall surface of the reaction vessel where the coal contacts,
Coal characterized in that the second system functions as means for preventing coal adhesion to the inner wall surface of the reaction vessel, and a gas containing a gas having high reactivity with coal char is blown into the reaction vessel from the second system. Rapid pyrolysis method.