JPH0559371A - Method for pyrolyzing carbonaceous material utilizing radiation - Google Patents

Abstract

PURPOSE:To efficiently obtain a gaseous or a liquid hydrocarbon useful as a chemical raw material, etc., under milder reaction conditions by pyrolyzing a carbonaceous substance in a gaseous atmosphere while irradiating the carbonaceous substance with beta-rays or gamma-rays. CONSTITUTION:A carbonaceous substance such as coal, coke, char, pitch, coal tar or heavy oil is pyrolyzed under ordinary, a reduced or a higher pressure to produce a gaseous hydrocarbon and/or a liquid hydrocarbon. In the process, the thermal decomposition is carried out at 700 deg.C temperature in a gaseous atmosphere such as hydrogen while irradiating the carbonaceous substance with beta-rays or gamma-rays. Thereby, since the pyrolysis of various carbonaceous substances including the coal is promoted not only by decomposition with heat but also decomposition of chemical structures with the radiation, both the amount and the quality of the products can be controlled at low temperatures and the pyrolysis can be promoted under milder conditions. As a result, the objective gaseous hydrocarbon or liquid hydrocarbon or both are produced with a high reaction efficiency.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention is one of the technologies for utilizing coal, in which a gas product obtained from coal is used as an energy source or a raw material for C ₁ chemistry.

Liquid products are also used as chemical raw materials.
The solid product is used as a reducing agent, a carbon material or the like. In such a coal utilization technology, it is possible to control the quantity and quality of the product under milder conditions.

[0003]

2. Description of the Related Art In a conventional coal pyrolysis method, when coal is heated, low molecular components in the coal are volatilized first, and then high molecular components are decomposed or polycondensed to release hydrogen. , It becomes a solid component of only carbon (char, coke).

For this reason, in the conventional method, the products obtained by pyrolysis largely depend on the properties of the raw coal. It is also affected by the pyrolysis conditions.

That is, (1) Coal having a small amount of volatile components has a large amount of solid products and a small amount of liquid / gas products. (2) Increasing the thermal decomposition temperature increases the amount of gas products. (3) When thermally decomposed under pressure, the amount of gas / liquid product increases in a reducing atmosphere.

Even if a large amount of liquid product is obtained in this way, if the coal to be used is decided, the only method is to change the pyrolysis conditions.

However, in an actual plant, the range in which the pyrolysis conditions can be changed is not so wide. Therefore, it may be difficult to control the operation according to the demand.

[0008]

SUMMARY OF THE INVENTION In view of the current state of the art, the present invention not only decomposes the coal structure by heat but also irradiates the coal structure with radiation by irradiating the coal with beta rays or gamma rays. It also promotes decomposition and allows control of the quantity and quality of the product at low temperatures.

[0009]

The present invention utilizes the fact that the chemical structure of coal is decomposed by beta rays or gamma rays.

That is, paying attention to the action of beta-rays or gamma-rays to break the chemical bond, it has been possible to thermally decompose coal at a low temperature of about 200 ° C. at which coal does not thermally decompose. This also applies to carbonaceous materials other than coal.

That is, according to the present invention, when a carbonaceous substance is pyrolyzed under atmospheric pressure, reduced pressure or high pressure to produce a gaseous hydrocarbon and / or a liquid hydrocarbon, the carbonaceous substance is exposed to beta rays or The carbonaceous material is thermally decomposed in a gas atmosphere while irradiating with gamma rays.

Here, examples of the carbonaceous material to be pyrolyzed include coal, coke, char, pitch, coal tar, heavy oil and asphalt, and any one kind or a mixture of two or more kinds. ..

As the gas atmosphere for the thermal decomposition, there may be mentioned any one kind or a mixed gas of two or more kinds of gases generated by the thermal decomposition of inert gas, hydrogen gas, steam and carbonaceous material.

If necessary, a liquefied solvent (tetralin, hydrogenated solvent, etc.) and a catalyst (iron sulfide, sulfur, N
It is also possible to perform thermal decomposition by adding (i-Co-Mo-based material, etc.).

[0015]

[Operation] Hereinafter, the case of coal will be described as an example.

In order to obtain a large amount of gas products from coal, it is necessary to sufficiently decompose the coal at a high temperature (1000 ° C. or higher) and a high pressure (50 atm or higher) to lower its molecular weight.

However, if coal can be pyrolyzed while being irradiated with beta rays or gamma rays, it can be sufficiently gasified without being pyrolyzed at high temperature and high pressure.

To obtain a large amount of liquid product from coal,
Irradiation with beta rays or gamma rays during heating of coal produces a large number of species with unpaired electrons.

By carrying out this operation under a hydrogen atmosphere, the chemical species having unpaired electrons are stabilized and a large amount of liquid product can be obtained.

That is, in order to control the quantity and quality of the products of thermal decomposition of coal, it is necessary to control the temperature of thermal decomposition, the dose of beta rays or gamma rays, and the gas atmosphere of thermal decomposition. it can.

[0021]

Example The experimental conditions are as follows. The carbonaceous material used is coal, which is wand one coal having the properties shown in Table 1.

First, this coal is crushed to 100 mesh or less. The coal is pyrolyzed under ⁶⁰ Co and ⁹⁰ Sr radiation.

Table 2 shows the results when the thermal decomposition temperature was changed while keeping the radiation intensity constant. Table 2 also shows the results in a hydrogen atmosphere, a steam atmosphere and a nitrogen atmosphere.

From this, it is understood that the present invention is more effective in promoting thermal decomposition than the conventional method.

Although examples of coal have been described above, coke, char, pitch, coal tar, and heavy oil,
Radiation was also found to be effective in promoting the thermal decomposition of asphalt.

That is, regarding these carbonaceous substances,
When pyrolysis was carried out in a hydrogen gas atmosphere at a temperature of 700 ° C. while irradiating the same amount of gamma rays as that of coal,
In each case, it was observed that the amount of solid product decreased within the range of 10 to 80%, and the amount of liquid product and gas product increased correspondingly.

Regarding coal liquefaction, 450 ° C., 170
In a hydrogen atmosphere at atmospheric pressure, using iron sulfide + sulfur catalyst,
Although 55% of liquid hydrocarbon was obtained, it was confirmed that 70 to 75% of liquid hydrocarbon was obtained by irradiating with radiation under the hydrogen atmosphere at 450 ° C. and 10 atm by using the same catalyst. ..

[0028]

[Table 1]

[0029]

[Table 2]

[0030]

Industrial Applicability According to the present invention, it is possible to promote the thermal decomposition reaction of various carbonaceous substances including coal, and to improve the efficiency of the reaction in industrial processes such as coal gasification, liquefaction and thermal decomposition. It is a very useful technology for

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Claims (1)

[Claims] 1. When a carbonaceous substance is pyrolyzed under atmospheric pressure, reduced pressure or high pressure to produce a gaseous hydrocarbon and / or a liquid hydrocarbon, the carbonaceous substance is irradiated with beta rays or gamma rays. However, the carbonaceous material is thermally decomposed in a gas atmosphere, and a method for thermally decomposing a carbonaceous material using radiation.