JPS6032894A - Manufacture of modified coal - Google Patents

Abstract

PURPOSE:To obtain highly humidity-proof modified coal from esp. low-grade coal, by bringing a low temperature-treated coal into direct contact with a mixed gas consisting of water vapor and the tar vapor distilled from said treatment. CONSTITUTION:Coal 1 such as low-grade one is ground followed by subjecting to low-temperature dry distillation, using a relevant unit 3, for example in an inert gas atmosphere, under normal pressure at 250-500 deg.C. By this operation, a mixed gas 4 consisting of water vapor and the tar vapor corresponding to the dry distillation temperature is distilled out, whereas, the resultant coal 5 is completely cooled by a cooling unit 6 followed by feeding said mixed gas to be brought into direct contact with it to effect secure coating of tar on its surface. The coated coal 7 thus obtained is cooled to about ordinary temperatures by another cooling unit 8 so as not to cause spontaneous ignition, thus producing the objective modified coal.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a method for producing modified coal, and particularly to a method for producing modified coal suitable for reforming low-rank coal into coal with excellent moisture resistance. It is about the method.

[Background of the invention]

As a technique for reforming low-grade coal such as sub-bituminous coal and lignite into coal with excellent moisture resistance, for example,
There is one described in 5 publications.

In the second technology, the coal is rapidly heated to a final heating temperature of 300 to 500 degrees Celsius at a heating temperature increase rate of 100 degrees Celsius or more, and then rapidly cooled to 250 degrees Celsius or less at a cooling temperature decrease rate of 50 degrees Celsius or more. oozes out onto the surface of the coal during thermal decomposition (
This method solidifies the liquid tar substance without volatilizing it, plugs the pores in the coal, lowers the specific surface area of the coal, and reduces the amount of moisture absorbed by the coal.

However, the tar obtained by such heat treatment of coal contains 90% of low-boiling substances with a boiling point of 200°C or less.
There are many. For this reason, the gasification rate of tar is fast, and it is very difficult to solidify the tar on the surface of the coal without gasifying it. There are problems with reforming coal into solid coal.

[Purpose of the invention]

The purpose of the present invention is to reliably coat the surface of low-temperature carbonized coal (hereinafter abbreviated as carbonized coal) with tar distilled by low-temperature carbonization treatment of coal, and to convert low-grade coal into a material with excellent moisture resistance. The object of the present invention is to provide a method for producing reformed coal that can be reformed into coal.

[Summary of the invention]

The present invention is characterized in that after coal is subjected to low-temperature carbonization treatment, a mixed gas consisting of tar vapor and water vapor distilled from the coal by the treatment is brought into direct contact with the carbonization coal. (It is intended to ensure that distilled tar is coated on the surface of carbonized coal by utilizing its one-stick property.

[Embodiments of the invention]

An embodiment of the present invention is explained using drawings. In drawing 0, coal, for example, low-grade coal 1 is crushed i! After pulverization in L2, it is supplied to the carbonization device 3, where it is subjected to low-temperature carbonization treatment under conditions of an inert gas atmosphere, normal pressure, and a temperature of 250°C to 500°C. Through this treatment, low-rank coal is A mixed gas 4 consisting of tar vapor and water vapor whose temperature is the carbonization temperature is distilled out. On the other hand, the carbonized coal 5 is transferred from the carbonized distillation device 3 to the cooling device 6.
It is then cooled from the carbonization temperature to a predetermined temperature. When the cooling process of the carbonized coal 5 is completed, the cooling device 6
A mixed gas 4 whose temperature is the carbonization temperature is supplied to the carbonization coal 5, and this mixed gas 4 is brought into direct contact with the carbonization coal 5. Thereby, tar is reliably coated on the surface of carbonized coal 5 by utilizing the selective adhesion of tar vapor in mixed gas 4, and coated coal 7 is obtained. Thereafter, this coated charcoal 7 is cooled to around room temperature in a cooling device 8 in consideration of spontaneous combustion and the like. In this way, modified charcoal 9 with excellent moisture resistance is produced.

An important factor here is the temperature of the carbonized coal when the carbonized coal and the mixed gas are brought into direct contact. The temperature of carbonized coal is 200℃
In the case of , the tar vapor liquefies and adheres to the carbonized coal surface,
On the other hand, the adhesion of water vapor to the carbonized coal surface does not cause any adsorption. When the temperature of carbonized coal is 250° C. or higher, tar vapor does not liquefy, so tar cannot be expected to adhere to the carbonized coal surface, and adsorption hardly occurs due to the tar composition. When the temperature of the carbonized coal is 110° C., tar vapor is liquefied and further adheres to the surface of the carbonized coal, and a portion of water vapor is adsorbed on the surface of the carbonized coal.

However, in this case, the amount of moisture adsorbed is about the same as the inherent moisture, and does not pose any practical problem. The temperature of carbonized coal is 110℃
In the following cases, the tar vapor is liquefied and further adheres to the carbonized coal surface, but at the same time the adsorbed moisture exceeds the inherent moisture, which is practically inconvenient. As a result of (2), the temperature of the carbonized coal when directly contacting the carbonized coal with the mixed gas is 110℃~
The temperature was defined as 250°C.

〔Effect of the invention〕

In the present invention, after the coal is subjected to low-temperature carbonization treatment as explained above, a mixed gas consisting of tar vapor and water vapor distilled from the coal from the treatment 1 is brought into direct contact with the carbonization coal.
Since the tar distilled by low-temperature carbonization treatment of coal can be reliably coached onto the surface of carbonized coal, it has the effect of reforming low-grade coal into coal with excellent moisture resistance.

[Brief explanation of the drawing]

The drawing is a process flow diagram showing an example of a modified coal production process in which the present invention is implemented. l...Low rank coal, 3...Carry distillation equipment, 4.
...mixed gas, 5...carbonized coal, 6...
...Representative of cooling system Patent attorney Akio Takahashi

Claims (1)

[Claims] 1. A modification characterized in that after coal is subjected to a low-temperature carbonization treatment, a mixed gas consisting of tar vapor and water vapor distilled from the coal by the treatment is brought into direct contact with the low-temperature carbonization-treated coal. How to make quality charcoal. 2. The method for producing reformed coal according to claim 1, wherein the temperature of the low-temperature carbonized coal is set at 110° C. to 250° C. and the mixed gas is brought into direct contact with the coal.