JPS5920388A - Improvement of coal - Google Patents

Abstract

PURPOSE:To improve low-quality coal into coal which has increased calorific value and capable of being effectively utilized as a fuel, etc. by deashing and granulating dry distilled coal in water using as a binder the oil prepd. in the system. CONSTITUTION:After crushed by a crusher 2, coal, e.g., low-quality coal 1 is dry distilled in a retort 3. Oil 4 and moisture 5 are extracted by the dry distillation. After further pulverized, the coal dried and made hydrophobic by the dry distillation is deashed and granulated in water by a submerged granulator 6 with addition of a binder. The oil prepd. in the system or the oil extracted by the dry distillation has properties of being completely recoverable by making the recovery temp. same to the dry distillation temp. Therefore, the oil extracted by the dry distillation is used as said binder. Ash 7 is separated in the process of the deashing and granulation by the submerged granulator 6, the oil and moisture are recovered from the formed granulated coal 8 by an oil recovery unit 9, and thus improved coal 10 is obtd.

Description

[Detailed description of the invention] The present invention relates to a method for reforming coal, particularly lignite.

The present invention relates to a method for reforming Vj coal, which is preferable for reforming into low-grade coal such as lignite and sub-bituminous coal by reducing its moisture content and ash content, thereby producing a low-grade coal.

Most of the coals that have been widely used as fuels are high-grade coals such as biting coal. On the other hand, although low-grade coal, such as lignite, accounts for about a quarter of all coals on earth, it is not used effectively due to its high moisture and ash content and low calorie content. Not yet reached. That is, in order to effectively utilize these low-grade coals as fuel, etc., it is important to reform them into coals with reduced moisture content and ash content and increased calorie content.

However, at present, as mentioned above, the use of high-quality coal is taking precedence, and therefore, appropriate reforming technology for the effective use of low-grade coal has not received attention and is an unfinished technology.

An object of the present invention is to provide a coal reforming method for reforming low-grade coal into calorie-amplified coal that can be effectively used as fuel.

The feature of the present invention is that after carbonizing coal, the carbonized coal or the coal coated with oil extracted by carbonization is decalcified and granulated in water using the oil generated within the system as a binder. This is to reduce the moisture content and ash content.

An embodiment of the present invention will be described with reference to the drawings.

In the drawing, coal, for example, low-grade coal 1, is pulverized in a pulverizer 2 and then carbonized in a carbonization device 3.

Here, the carbonization temperature is the temperature at which hydrogen is removed, methane gas is hardly extracted, and oil and water are extracted.
It is regulated by the type of charcoal and oil extraction tray. In addition, the carbonization pressure is 'heavy pressure'. This carbonization extracts oil and water 5. It is dried by carbonization. During this deashing and granulation process, ash 7 is separated. Thereafter, oil and moisture are recovered from the granulated coal 8 formed by deashing and granulation in an oil recovery device 9. Here, the recovery temperature is the temperature at which the required oil content I can be recovered, that is, the temperature at which the required oil content I can be recovered, because if all the oil content is recovered from the granulated coal 8, the moisture resistance will be slightly reduced and it will become pulverized and easily ignite. Be sure to select a temperature lower than the actual temperature. In addition, the recovery pressure is set to normal pressure or slightly negative pressure in order to promote recovery of oil at the same recovery temperature.

Conventionally, in the deashing granulation of high-grade coal, heavy oil, which is relatively inexpensive and does not evaporate at room temperature, has generally been used as a binder. However, when heavy oil is used, recovery from granulated coal cannot be performed well, so it is necessary to constantly supply or replenish the heavy oil from outside the system. On the other hand, the oil produced within the system, that is, the oil extracted by carbonization, is
It has the property of being able to be completely recovered by setting the recovery temperature to the carbonization temperature as shown in 1c above. Therefore, in the present invention, an oil extracted by carbonization is used as a binder. However, since the oil extracted by carbonization alone was insufficient, it was decided to also use the oil generated within the system, that is, the oil recovered from the granulated coal.

In this way, since the binder uses oil generated within the system, that is, oil extracted by carbonization and oil recovered from granulated coal, there is no need to supply or replenish oil from outside the system. do not have. Of course, at the start of this process, it is necessary to prepare in advance the amount of oil necessary for deashing and granulation by carbonization or recovery.

According to this example, the water content and ash content are each 25%,
When 35% low rank coal was reformed, the following results were obtained.

First, the above-mentioned low-grade coal was pulverized to a size of 16 mm and carbonized under the conditions of carbonization temperature = 400°C2 carbonization pressure = normal pressure. As a result, four parts of oil were extracted, water was extracted, and the mixture was dried and made hydrophobic. This dried and hydrophobized coal was further finely pulverized to -74 μm and 80%, and then 20% of a binder was added and deashed and granulated in water. This reduced the ash content to 20%. Thereafter, oil and moisture were recovered from the granulated coal. In this case, the oil content extracted from one carbonization is 4%, and since 16% of the oil content is insufficient as a binder, the recovery temperature is set to 350°C so that 16% of oil content is recovered from the granulated coal. The recovery pressure was normal pressure. The moisture content of the finally obtained modified coal was about 14% under constant humidity conditions, and the ash content was 20%.

In addition to this example, the carbonized coal was coated with oil extracted after carbonization-2, and the coal was decalcified and granulated in water using the oil generated in the system as a binder. There is no particular problem.

As explained above, in the present invention, after carbonizing coal,
Carbonized coal or coal coated with oil extracted by carbonization is deashed and granulated in water using the oil generated within the system as a binder to reduce the moisture content and ash content. This has the effect of reforming low-grade coal into coal with increased power that can be effectively used as fuel.

[Brief explanation of drawings]

, the drawing is a process flow diagram showing an example of a coal reforming process in which the present invention is implemented. 1...Low rank coal, 2...Crusher, 3.
- Curved carbonization equipment, 4... Oil content, 5... Moisture, 6. Beating/underwater granulation equipment, 7... Ash content, 8.
... Granulated coal, 9 ... Oil recovery device, 10
...Reformed coal agent Patent attorney Usui 1) Toshiyuki

Claims (1)

[Claims] 1. After carbonizing coal, the carbonized coal or the coal coated with oil extracted by carbonization,
A patented coal reforming method that uses oil produced within the system as a binder and performs deashing and granulation in water. 2. The oil content generated in the f+iJ system is the oil content extracted from the Aft coal content and the oil content recovered from the granulated coal formed by the M deashing granulation process, as described in Paragraph 1 of the Patent NFI Request. Coal reforming method.