JPH02302308A - Production of activated carbon - Google Patents

Abstract

PURPOSE:To obtain activated carbon having improved characteristics by finely crushing a compound mainly comprising two species of coal group having specific properties, molding under pressure, carbonizing and activating. CONSTITUTION:A compound mainly composed of 30 to 95wt.% coal group A and 70 to 5wt.% coal group B having following properties is finely crushed, molded under pressure, adjusted to <=10mm thickness or <=10mm granular diameter and carbonized in a coking equipment of chamber oven type, then activated to afford the objective activated carbon. Coal group A: (a) 0.4 to 1.0 averaged optical reflectance (RO), (b) <=2.0(log DDPM) Giesler maximum fluidity(MF) and (c) <=3 free swelling index. Coal group B: (a) 0.6 to 1.2 averaged optical reflectance (RO), (b) 2.0 to 4.5 (log DDPM) Giesler maximum fluidity(MF) and (c) >=3 free swelling index.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a method for producing activated carbon.

In the following specification, "%" means "% by weight"
means.

Prior Art and its Problems First, an explanation will be given with reference to FIG. 1, which shows an example of the flow of an activated carbon manufacturing method according to the prior art. The raw coal is pre-dried at 200°C in a dryer (1), and then pulverized in a pulverizer (2).
After pulverizing the coal into approximately 200 mesh pieces or less, the coal is stored in a coal storage tank (3). Multiple types of coal, which are usually stored in multiple coal storage tanks (not shown), are cut out at a constant blending ratio, and a mixer (
After mixing in step 4), heating and molding in a molding machine (5) at about 200 ml, the particle size is adjusted in a granulator (6). Next, the particles are sieved to a predetermined particle size (usually about 7 to 20 mesh) using a screen (7), and the coarse particles are returned to the granulator (6) and the fine particles are returned to the mixer (4). The raw material whose particle size has been adjusted is sent to the carbonization furnace (8)
After baking and coking at about 300 to 700°C, the coke is activated with steam at about 700 to 1000°C in an activation furnace (9), and then obtained as a product.

However, such conventional methods require high equipment costs, resulting in high production costs for activated carbon.

In view of the problems of the prior art as described above, the present inventor came up with the idea of manufacturing activated carbon at low cost by using existing indoor coke oven equipment for the steps up to carbonization. However, since the coal blends used as raw materials for activated carbon production in conventional methods do not form lump coke,
It turned out that extrusion was not possible and the above idea could not be implemented. This is a natural result because the coal blend used as a raw material for such activated carbon production is not intended to be carbonized in a coke oven.

It is also possible to activate conventional coke produced in existing chamber-type coke oven equipment, but in this case, the specific surface area and pore volume of the activated carbon obtained are small, so the performance as activated carbon is insufficient. was found to be inferior. This is because such coke is not intended to be used as a raw material for producing activated carbon, and this is also a natural result.

Means for Solving the Problems As a result of further research, the inventor discovered that a specific coal group A
When using a mixture whose main constituent composition is Coal Group B as a raw material, it becomes possible to produce activated carbon by activating coke carbonized in existing room furnace coke oven equipment,
We found that the physical properties of the obtained activated carbon were also satisfactory, and based on these new findings, we have already filed a patent application (Japanese Patent Application No. 81093/1983; hereinafter, the invention disclosed herein is referred to as the earlier patent application). invention).

As a result of further research, the inventors of the present invention discovered that activated carbon with more excellent properties could be obtained by improving the prior invention.

That is, the present invention provides the method for producing activated carbon shown below.

■Coal group A30-95 each having the characteristics shown below.
% and coal group 870-5% is finely pulverized and pressure molded to a thickness of 10 am or less or a particle size of 10! A method for producing activated carbon, which is characterized in that the activated carbon is adjusted to less than m, and then carbonized and activated in a room-furnace coke oven facility: Coal group A: (a) Average optical reflectance (R0); 0.4 to 1 .0 (b) Gieseler maximum flow rate (MF).

Less than 2.0 (l og DDPM) (c) Button index; Less than 3 Coal group B: (a) Average optical reflectance (R0); 0.6 to 1.2 (b) Gieseler maximum fluidity (MF); 2.0-4.5
(1ogDDPM) (c) Button index: 3 or more.

■The blend is 50-95% of coal group A and 850-5% of coal group
%. The method for producing activated carbon according to item 1 above.

In the present invention, the proportion of coal group A30 in the raw material is
~95%, and the coal group is 870~5%. For example, when coal group A alone is used as a raw material, extrusion is impossible because lump coke is not formed, and indoor furnace coke oven equipment cannot be used. Furthermore, even when coal group A alone is used as a raw material and carbonization and activation are performed by the conventional method shown in FIG. 1, good quality activated carbon is generally not obtained. Furthermore, when coal group B is used alone, only low-quality activated carbon with a small surface area and low adsorption capacity is generally obtained, regardless of the carbonization and activation steps. Furthermore, even when the mixing ratio of coal group A and coal group B falls outside the predetermined range, activated carbon of the desired high quality is generally not obtained. In order to further improve the quality of the finally obtained activated carbon, it is more preferable that the proportion of coal group A in the raw material is 50 to 95% and 850 to 5% of coal group A.

The present invention, which uses a mixture of coal group A and coal group B as raw material,
As mentioned above, the activated carbon manufacturing method according to the prior art shown in Fig. 1 may be used, but as shown in Fig. 2, it is more preferable to use a method of using room furnace type coke oven equipment as the carbonization furnace. preferable.

That is, raw coal groups A and B are each crushed by a crusher (1
In step 1), the coal is pulverized to about 74 μm or less according to a conventional method, and then stored in a coal storage tank (12). Next, the coal stored in each coal storage tank is cut out at a predetermined blending ratio, mixed with a mixer (13), and pressure-molded into a flat plate shape with a molding machine (14). Alternatively, unpulverized coals A and B stored in each coal storage tank may be cut out at a predetermined blending ratio, mixed in a mixer (13), the resulting blend may be pulverized, and then pressure molded. good. The pressure during pressure molding is 1 ton/cm or more for linear pressure and 1 ton/cm for surface pressure, as in the conventional method.
It is preferable to set it to ton/cj or more. Next, the obtained molded product is adjusted to a thickness of 10 mm or less (more preferably about 2 to 5 mm) or a particle size of 10 mm or less (more preferably about 2 to 5 mm) using a crusher (15), and then placed in a coke oven ( 16) and carbonized at about 600 to 1300°C.

The generated carbide is discharged from the coke oven (16) in a bulky state with the ends of each particle constituting the carbonized compact attached, so it can be easily divided into particles by, for example, a crusher (17). be able to. The strength of this carbonized compact is such that it can be extruded from the coke oven (16) and easily divided into individual particles by hand, so a particularly powerful device is required as the crusher (17). There is no need to use it. In order to avoid excessive crushing from the viewpoint of yield, it is preferable that the crusher (17) has a low capacity as long as it can divide the particles into individual particles. The divided carbide is sifted with a screen (18) and is separated by 0.5 to 5 m.
The product is sent to an activation furnace (19), where it is activated with steam at about 500 to 1200°C according to a conventional method, and is made into a product. The coarse particles obtained by the screen (18) are passed through a crusher (
17) and the fine particles are recycled as breeze. In the present invention, when based on the raw material carbide, the yield of the sieved carbide can reach about 80% (0.5 to 4
mm). In the case of the prior invention mentioned above, the yield under similar conditions was about 50%, so it is clear that the yield improvement according to the present invention is remarkable. the result,
The yield of activated carbon of the present invention based on raw material coal is also about 23%, which is significantly improved compared to about 15% of the prior invention.

In the present invention, depending on the quality of the coal group used and the quality of the activated carbon required, a binder can be used in combination within a range not exceeding 20% of the weight of the coal. As a binder, commonly used coal tar, pitch,
Use pulp waste liquid, etc.

The activated carbon obtained by the method of the present invention usually has a specific surface area of 900 rrr/g or more, depending on the type of raw materials, manufacturing process, etc.
Pore volume 0.5cc/g or more, iodine adsorption amount 950mg
It is possible to design physical properties with a packing density of 0.49 g-/cm3 or more. In addition, the activated carbon obtained by the method of the present invention is approximately equal to or higher than the activated carbon obtained by the conventional method in terms of hardness, methylene blue decolorizing power, etc.

Effects of the Invention According to the present invention, by blending specific groups of coals that are unsuitable as raw materials for producing activated carbon on their own, it has become possible to carry out carbonization using an existing indoor coke oven. , equipment costs are significantly reduced. Furthermore, since the product yield is significantly improved, cost reductions from this point of view are also achieved.

Moreover, the properties of the obtained activated carbon are also significantly improved.

Furthermore, by changing the blending ratio of coal group A and coal group B and the type and amount of additives such as binders,
It is possible to adjust the performance of activated carbon.

EXAMPLES Examples will be shown below to further clarify the features of the present invention.

Example 1 65 parts by weight of coal A having the characteristics shown below and 830 parts by weight of coal were blended with 5 parts by weight of pitch, and after pulverizing the mixture so that 95% or more passed through 200 meshes, a linear pressure of 3 tons/ It was molded into a plate with a thickness of 5 mm. Next, this molded body was crushed by a crusher and then sieved to obtain particles with a particle size of 0.6 to 5 mm, which were carbonized at about 900°C in an indoor coke oven to produce the obtained lump coke. was gently crushed and sieved. Of these, 0.5~
The four-fin specimen was steam activated at 900° C. for 5 hours in a rotary kiln to produce activated carbon.

Coal A: (a) Average optical reflectance (R0); 0.61 (b) Gieseler maximum fluidity (MF); 1. 7 (c) Button index: 2 Coal B: (a) Average optical reflectance (R0); 1.0 (b) Gieseler maximum fluidity (MP); 3 (c) Button index; 6 Based on coking coal The yield of activated carbon is 23%,
Its physical properties are as follows.

Packing density - 0.49g/cm3 JIS hardness = 98% Methylene blue decolorizing power = 170ml/g or more Specific surface area =
929r! f/g BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flowchart showing an example of a conventional activated carbon production method, and FIG. 2 is a flowchart showing an example of an activated carbon production method according to the present invention.

(1)...Dryer (2)...Fine crusher (3)...Coal storage tank (4)...Mixer (5)...Molding machine (6)...Crusher (7) )...Screen (8)...Carbonization furnace (9)...Activation furnace (11)...Crusher (12)...Coal storage tank (13)...Mixer (14)... Molding machine (15)...Crushing machine (16)...Screen (17)...Room oven coke oven (18)...Crushing machine (19)...Activation furnace (and above) Procedure amendment Indication of the case 1999 Patent Application No. 28985 2 Name of the invention Method for manufacturing activated carbon (028> Osaka Gas Co., Ltd. 4 Agent Sawanotsuru Building fij06, 2-1-2 Hirano-cho, Chuo-ku, Osaka City
(203) 0941 Voluntary Issue 6 The "Detailed Description of the Invention" section, the "Brief Explanation of the Drawings" section in the specification subject to amendment, and Contents of Drawing Amendment 1: The statements in the description are corrected as shown in the table below. do.

2. Page 15 of the specification, lines 1 to 3 r(17)...Room oven coke oven (18)...Crusher (19)...Activation furnace" is replaced with the following: correct.

r(17)...Coke oven (18)...Crushing machine (19)...Screen (20)... Activation Furnace" 3. Correct the drawing No. 2 as shown in the attached sheet.

(Above) July 11, 1990 Toshi Uematsu, Commissioner of the Japan Patent Office 1 Description of the case 1999 Patent Application No. 28985 2 Name of the invention <028) Osaka Gas Co., Ltd. 4 Agent Hirano-cho, Chuo-ku, Osaka City 2-1-2 Sawa no Tsuru Building 2! ! 0
6 (203> 0941 Contents of the July 3, 1990 amendment 1 The statements in the specification are corrected as shown in the table below.

2 Lines 1 to 3 of page 15 of the specification [(17)...Room furnace type coke oven (18)...Crusher (19)...Activation furnace'' has been replaced with the following: correct.

r(17)...Coke oven (18)...Crushing machine (19)...Screen (20)...Instalment Furnace" 3. Correct Figure 2 of the drawing as attached.

(The contents of Figure 1 remain unchanged) (that's all)

Claims (2)

[Claims] (1) Coal group A30~ having the characteristics shown below
A mixture whose main composition is 95% by weight and 70 to 5% by weight of coal group B is finely pulverized, pressure-molded, and adjusted to a thickness of 10 mm or less or a particle size of 10 mm or less, and then processed into an indoor coke oven equipment. A method for producing activated carbon characterized by carbonization and activation in: Coal group A: (a) Average optical reflectance (R_0); 0.4 to 1.0 (b) Gieseler maximum fluidity (MF); 2.0 (log
DDPM) (c) Button index; less than 3 Coal group B: (a) Average optical reflectance (R_0); 0.6 to 1.2 (b) Gieseler maximum fluidity (MF); 2.0 to 4 .5
(logDDPM) (c) Button index: 3 or more. (2) The blend is 50 to 95% by weight of coal group A and coal group B.
5. The method for producing activated carbon according to claim 1, wherein the composition is 50 to 5% by weight.