JPS59140295A - Pretreatment of coal - Google Patents

Abstract

PURPOSE:To prepare a coal/oil slurry having excellent stability, by adding a solvent to pulverized coal, followed by heat treatment and dispersion into a heavy fuel oil. CONSTITUTION:A solvent (e.g. coal tar) is added to coal pulverized to such a particle size that 150-mesh particles account for 70% or higher. The mixture is heated at 100-450 deg.C for a few hours to remove water, gas, etc. adsorbed by coal particles. Then the coal particles are added to a heavy fuel oil kept at 50- 80 deg.C, followed by a vigorous agitation for homogeneous dispersion.

Description

[Detailed Description of the Invention] Currently, 1 coal-bent slurry production uses 70-80% of coal as 2
After being finely pulverized to 0.00 mesh (74μ) or less, each coal particle is added to M shell fuel oil heated to 50 to 80°C, and then vigorously stirred and mixed to form fuel i+t-+. evenly distributed. However, coal particles exhibit hydrophilic properties due to adsorbed water and polar groups on the surface of the fuel.
Coal particles have many pores, which increases the surface area and increases the surface free energy, making it easier to aggregate and coalesce, and coal particles increase the particle size. 1 increases the sedimentation rate of coal particles,
Sedimentated and separated coal particles form strong aggregates and do not reflow.In order to prevent this, a stabilizing agent of 0.5% or less is added to the mixture of finely pulverized coal particles and N-quality fuel. By adding a stabilizer, the stability of coal particles in heavy fuel oil is increased and a stable coal-bent slurry is produced. However, the addition of a stabilizer does not provide sufficient stability to the slurry.

As time passes, oil penetrates into the pores of the coal, resulting in gas generation [2, accumulation].

This has led to problems such as a decrease in the amount of oil used as a bath agent and a rapid increase in viscosity, making it difficult to operate the bath.Therefore, some kind of countermeasure is desired.

Therefore, the invention was made with the purpose of providing a method for pre-treating coal that would improve the stability of coal-curved slurry and make it possible to scale it, by adding a solvent to finely pulverized coal. 9 Heat treatment at the blade edge while stirring under normal pressure or pressurization, i+11, preferably 100 to 450
The present invention provides a method for pre-treating coal, which is characterized by heat-treating in a temperature range of °C for from zero hours to several hours. By mixing and preparing a homogeneous coal-cured slurry, the particle size of the applied coal is reduced by half compared to the case without the addition of a stabilizer or the conventional pretreatment. It is possible to prepare a thicker (but more stable) slurry than when no treatment is carried out, and it is possible to fully satisfy industrial requirements. This is due to the following reasons. Dehydration and degassing reactions occur, and adsorbed water and adsorbed residue on coal particles are removed, increasing the wettability of oil and coal.

Furthermore, due to the thermal decomposition of coal, the polar groups (-=oH+ -COOH, c:=o, etc.) exhibiting phobic properties on the surface are significantly reduced, resulting in a decrease in oleophobicity, and furthermore, there is a Because the methyl group showing affinity iiJ generated from the solvent or by thermal decomposition of the solvent binds to the affinity i+
This is because the IJ properties are significantly improved.

In addition, because the easily soluble parts of the coal particles dissolve in the bath agent, the coal particles become finer and the sedimentation rate decreases, and the pores of the undissolved particles are filled with dissolved coal or the bath agent. Therefore, oil does not seep into the coal pores over time and the viscosity rapidly increases, and the effective surface area is significantly reduced compared to finely pulverized raw material coal.

Since the surface area is increased due to the finer grains and the destabilization of the slurry is prevented, the stability of the two-coal-bent slurry can be greatly improved.

To be more specific, this pretreatment.

Because coal particles dissolve and become finer, the particle size of the coal that was used for producing coal-curved slurry was pulverized until the particle size of 20.0 mesh or less becomes 70% or more. If this pretreatment method is used after pulverizing the coal until it becomes pulverized, it will be possible to obtain a stability higher than that currently available, and it will be possible to prepare a stable slurry that is required industrially. It was found that it was possible to significantly save power.

For this pretreatment, coal-based solvents such as coal tar, Acitra, creosote oil, and targotchi, petroleum-based solvents such as vacuum distillation residue oil, atmospheric distillation residue oil, C heavy oil, and crude oil can be used. ′ can also be used.

Petroleum-based bath additives have the advantage of being easily available in large quantities.

However, in the no-pretreatment method, the treatment temperature is limited depending on the solvent and type of coal used, but when using vacuum distillation residue oil or full pressure distillation residue oil, the treatment temperature is preferably near the pour point of the coal.
A short treatment time is appropriate, but if the treatment temperature is longer than necessary (Ii"l The formation of carbon microbeads (organic solids) collects and aggregates, and the apparent diameter of the coal particles increases, making them more likely to settle.As they become finer through dissolution and become less effective in reducing sedimentation, temperature and treatment It is considered that the time must be selected according to the type of coal.Also, the non-pretreatment method can be performed in an inert atmosphere under normal pressure or under pressure, and the temperature is 100℃ to 450℃.
Since the heat treatment is carried out under mild conditions at ℃, there are almost no operational problems, and it is an extremely effective pretreatment method for industrial use, as it significantly reduces fA shavings and is economically advantageous. think.

Next, the present invention will be explained based on one embodiment.

After pulverizing the Lisker coal in a wet mill so that 70% or less of 200 meshes or less is mixed, Middle East Yarn EC heavy oil is heated to 300°C, and coal/7 is mixed into it.
Coal was added so that the IiI ratio was 2/1, and the mixture was maintained for 2 hours with sufficient stirring. After that, it was cooled to 70℃, C heavy oil was added so that the lime/oil ratio was reduced to 1/1, and a stabilizer made from an improved isocyanate-modified polyol was added to it.
．． 2 wt% 710 and then 50 with Ho73 + 4 no
0Or', plm Mix for 30 minutes and add coal-i+4J suley? Made by A. Therefore, a rod penetration test was conducted to check the stability of the slurry. In addition, untreated slurry is
7J [J
After stirring and mixing at 500'Or, p, m for 60 minutes, a test sash was prepared.

(Results) Middle Eastern C heavy oil properties viscosity 50C, 160℃)
25C, P (80℃) ratio 0.92.
9/ii6[)℃) 0.9()6so/d+8[]
℃）Lisu J-Carbohydrate Moisture 2.0% Bulk specific gravity 187 Particle size 200>71 ratio
The rod penetration test results show that the slurry treated at 300℃ at 0 weight 41+ has a rod penetration of 1 hour and 1ilij, and all of the additive + 111J agents. 67
Comparing this to 26 seconds in 30 days despite a significant decrease in time, and 25 seconds in 14 days for untreated suri.

It is shown that the stability was doubled by "Precondition 1".

The above results show that the slurry stability is significantly improved when coal is treated with a solvent at a convex temperature, and the single-coat pretreatment method is not old!
It turned out to be an effective method.

Agent Tatsuma kneels down; Il,□:1. .

Procedural Amendment (Format) June 60, 1980 Commissioner of the Patent Office Kazuo Wakasugi Case Description 1987 Patent Application No. 187292 Name of the invention Coal pre-treatment method Person who makes amendments Relationship to the case Patent applicant Address: 8-2, Chomi, Marunouchi, Chiyoda-ku, Tokyo Name
Electric Power Development Co., Ltd. Address 2-2-1 Otemachi, Chiyoda-ku, Tokyo Name (009) Ishikawajima Harima Heavy Industries Co., Ltd. Address 2-14 Higashiyosakicho, Ikuta-ku, Kobe, Hyogo Name (097) Kawasaki Heavy Industries Co., Ltd. Address: 5-1 Marunouchi-chome, Chiyoda-ku, Tokyo Name (
510) Hitachi, Ltd. Agent address: Mitsubishi Heavy Industries, Ltd., 2-5-1 Marunouchi, Chiyoda-ku, Tokyo (telephone number: 212-3111) February 28, 1980: "Name of the invention" in the specification subject to amendment Contents of Column Amendment “Coal Pretreatment Method” in the title of the invention has been changed to [Coal Pretreatment Method θ
Correct knee 1.

Claims (1)

[Claims] Coal is processed so that finely ground coal particles are homogeneously and stably dispersed in heavy fuel oil so that it can be combusted in the same way as normal liquid fuel. 1. A pretreatment method for coal, which is characterized in that it is heat-treated with a heat treatment.