JPH0248409A - Production of active coke - Google Patents

Abstract

PURPOSE:To produce an active coke having high mechanical strength and SO2 absorptivity by compounding a finely crushed coal with a specific amount of wood crushed to a size smaller than a specific size, adding a binder, compression-molding the mixture and carbonizing the product. CONSTITUTION:A coal composed of caking coal or a mixture of caking coal and non-caking coal and finely pulverized to preferably <=300mum is compounded with 0.2-30wt.% of wood crushed to particle diameter of <=100mum. The coal compounded with the wood is added with about 10-15wt.% of a conventional binder such as soft pitch or pulp spent liquor and formed by compression molding. The formed coke is charged in a carbonization furnace and heated at about 900 deg.C to obtain a carbonized product. It is preferable to add about 5-20% of water in the molding process to facilitate the molding. The obtained carbonized product can be used as the active coke as it is, however, it is activated by conventional method in the case of requiring an active coke having higher pore volume.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for producing activated coke. The activated coke produced by this method is mainly used as a carbon material for waste gas desulfurization.

(Prior art) Activated coke using coal as a raw material is manufactured by controlling the blending amount of various types of coal, adding a binder, making molded coal, and carbonizing and activating it in the same way as the production method of molded coke for metallurgy. (Japanese Unexamined Patent Publication No. 57-123809), ■
A method of manufacturing activated coke by forming a mixture of coal into semi-formed coke, mixing it with coal and adding a binder, and carbonizing the formed coal to activate coke (Japanese Patent Laid-Open Publication No. 100910/1982), After oxidizing the coking coal, a binder is added,
It is made into briquette charcoal and manufactured by carbonizing the briquette.

A feature of these activated coke manufacturing methods is that in the process of carbonizing the briquettes, the briquettes are softened and melted so that they do not exhibit any expansion phenomenon.

In other words, the activated coke produced from the blended raw materials is 50
2. It must have well-developed pores to increase adsorption capacity. In order to generate many pores, in order to prevent the coal from exhibiting a high softening and melting phenomenon during the carbonization process, it is necessary to add a large amount of non-caking coal or to treat some of the coal with coke or oxidation treatment. It is necessary to Japanese Patent Publication No. 57-12
In Publication No. 3809, lignite or subbituminous coal is blended in order to control the caking of the blended coal to a low level. Further, in JP-A-57-10091C1, semi-formed coke is produced from coal, this semi-formed coke is used as the main raw material, and the briquette is devised so that it will not soften and melt during the carbonization process and exhibit an expansion phenomenon. Furthermore, for boat fishing, caking coal is oxidized to prevent the briquette from exhibiting the softening and melting phenomenon during the carbonization process.

(Problem to be solved by the invention) As described above, in the conventional method of blending lignite or subbituminous coal, since a large amount of coking coal cannot be used, the amount of shrinkage becomes large during the carbonization process of briquette coal. It shows a phenomenon in which the bond between particles weakens and the mechanical strength of activated coke decreases.
Undesirable. On the other hand, the method of converting low-coalization coal into semi-formed coke and then blending it with coal seems to produce activated coke that is excellent as an adsorbent, but it is complicated because semi-formed coke must be produced. . Furthermore, oxidation of coking coal requires special equipment for oxidizing coal.

Compared to the above-mentioned known technologies, it has strong mechanical strength and 5.
There is a strong desire to establish a method for producing activated coke that has high 02 adsorption capacity and can be produced at low cost.

(Means for Solving the Problems) The present invention blends 0.2% by weight or more and less than 30% by weight of wood that has been crushed to a particle size of 100 μm or less to finely crushed coal,
This is a method for producing activated coke, which is characterized by adding a binder, molding under pressure to obtain briquette coal, and then carbonizing it.

(Function) As a result of various research into establishing a method for producing activated coke that is simple and has high mechanical strength, the present invention has discovered a method for producing activated coke that utilizes inexpensive wood.

The finely pulverized coal in the present invention is coal that has been pulverized by caking coal alone or by blending non-caking coal with caking coal, but preferably is coal that has been pulverized to 300 μm or less.

The reason why finely ground wood is added is that the gas generated during the heating process of the wood reduces the caking properties of the caking coal, and since the wood does not soften and melt, it is interposed between the caking coal particles and increases the hardness of the coal particles. This is to prevent welding and form many pores.

The reason why the amount of wood added to finely ground coal is specified to be 0.2% by weight or more is because if the amount is less than 0.2% by weight, it will not be possible to promote infusibility of the coal if the caking property of the coal is high. It's for a reason. The reason why the upper limit was set to less than 30% by weight is that if more than 30% by weight is added, the mechanical strength of the briquette coal will decrease, pulverization will occur during the activated coke production process, and the yield of activated coke will decrease, making it uneconomical. It's for a reason. If the particle size of the crushed wood exceeds 100 μm, the contact area with coal is too small and wood segregation occurs. Therefore, if the particle size is set to 100 μm or less, and preferably 50 μm or less, segregation can be prevented and the particle size of the wood should be 50 μm or less. The contact area is large, which is good for making coking coal infusible.

Furthermore, as a substitute for wood, coconut shells, valves, waste paper,
Sugar cane residue generated during sugar refining or fibrous residue during shochu production can also be used.

A binder is added to a mixed charcoal mixture of coal and finely ground wood, and the mixture is pressurized and molded to form charcoal, which is then charged into a carbonization furnace and heated to approximately 900°C.
The temperature is raised to 100% to form a carbide. This carbide is used as is as activated coke. However, if activated coke with a larger pore volume is required, it may be further activated by a known method.

In addition, the binder added in the present invention is pressure molded,
Molded coal may be used as long as it has a bonding strength to the extent that it does not turn into powder when carbonized, and for example, known caking agents such as soft pitch and valve waste liquid can be used. The amount of this binder added is about 10 to 15% by weight.

Furthermore, in order to facilitate molding, the water content is reduced by 5 to 2
It is good to add about 0%.

For carbonization of the briquette coal, either known indirect heating or direct heating using combustion exhaust gas may be used.

(Example) Next, the present invention will be described based on an example. Table 1 shows the properties of the coal and wood used.

Table 1 Example 1 Coal A finely pulverized to -74 μm 60.0% by weight -80
Coal B 3 (1,0% by weight, and -
10.0% by weight of wood crushed to 100 μm was mixed to obtain mixed charcoal. 85.0% by weight of this mixed carbon and 15% soft pitch as a binder. After mixing % OJi and making the water content 10%, the mixture was pressurized and molded using a disc pelleter to obtain briquette charcoal.

This briquette was charged into a carbonization chamber maintained at 200°C in a direct heating carbonization furnace using combustion exhaust gas having an internal volume of 651 cm, and the temperature was raised to 900°C at a heating rate of 2.0°C/min to produce activated coke.

The produced activated coke was evaluated by measuring the SO□ adsorption amount.

The method for measuring the amount of SO□ adsorption is as follows.

75g of activated coke was charged into a 28mmφ stainless steel tube, and at a sample temperature of 120°C, an SO2 concentration of 0.
77 volume % gas flow rate 353 n/hr superficial velocity 0.2
The flow was carried out at 8 m/sec for 4 hours, and 502 was adsorbed onto the activated coke. Next, activated coke with SO2 adsorbed was added to
Heating to 00°C, SO□ desorption was carried out for 2 hours while passing N2 gas at 120 fL/hr, SOz was absorbed into a 3% by weight hydrogen peroxide solution, and the concentration of HJ desorbed and SO2 was measured by the arsenazo method. The adsorption amount of activated coke was measured. As a result, the adsorption amount of activated coke was 71 mg/g.

Example 2 Coal A finely ground to 200 μm 80.0% by weight, -
Finely pulverized to 50 μm; 20.0% by weight of shredded wood was mixed to obtain mixed charcoal. 85.012% of this mixed coal and 15.0% by weight of soft pitch as a binder were mixed to make the moisture content 10%, and then pressure molded using a disc pelleter to obtain molded coal.

This briquette was charged into a carbonization chamber maintained at 200°C in a direct heating carbonization furnace using combustion exhaust gas with an internal volume of 65λ, and the temperature was raised to 900°C at a heating rate of 2.2°C/min to produce activated coke.

Results of measuring the SO2 adsorption amount of the generated activated coke 8
It was 1 mg/g.

Example 3 Coal A finely ground to 100 μm 40.7% by weight 50
μmk: 0% by weight of finely ground coal B4O, and -10
0.3% by weight of wood crushed to 0 μm was mixed to obtain mixed charcoal. 90.0% by weight of this mixed charcoal and 10.0% by weight of soft pitch as a binder were mixed to make the moisture content 10%, and then pressure molded using a disc beretter to obtain molded coal.

This briquette was heated in an indirect heating carbonization furnace with an internal volume of 100°C for 200 min.
Charged into a carbonization chamber maintained at ℃, heating rate 15℃/min.
The temperature was raised to 900°C to produce activated coke.

The amount of adsorbed 502 of the generated activated coke was determined by rl[11] and was found to be 60 mg/g.

Example 4 -75.0% by weight of coal A pulverized to -50 μm and -3
25.0% by weight of wood crushed to 0 μm was mixed to obtain mixed charcoal. 85.0% by weight of this mixed coal and 15.0% by weight of soft pitch as a binder were mixed to make the moisture content 10%, and then pressure molded using a disc beretter to obtain molded coal.

This briquette was charged into a carbonization chamber maintained at 250°C in a direct heating carbonization furnace using combustion exhaust gas with an internal volume of 65 fL, and the temperature was raised to 900°C at a heating rate of 2.5°C/min to produce activated coke.

Results of measuring the amount of SO□ adsorption of the generated activated coke
a mg/g.

Comparative Example 1 Coal A finely pulverized to -74 μm 69.9% by weight -80
830.0% by weight of coal finely ground to μm, and -10
0.1% by weight of wood crushed to 0 μm was mixed to obtain mixed charcoal. 850% by weight of this mixed coal and 15.0% by weight of soft pitch as a binder were mixed to give a moisture content of 10%, and then pressure molded using a disc beretter to obtain molded coal.

This briquette was charged into a carbonization chamber maintained at 200°C in a direct heating carbonization furnace using combustion exhaust gas with an internal volume of 65 fL, and the temperature was raised to 900°C at a heating rate of 2.0°C/min to produce activated coke.

Results of measuring 502 adsorption amount of generated activated coke 1
At 2 mg/g, the amount of SO□ adsorption decreased significantly.

Comparative Example 2 Coal A finely pulverized to 74 μm 65.0% by weight
35.0% by weight of wood crushed to 00 μm was mixed to obtain mixed charcoal. After mixing 90.0% by weight of this mixed coal with 10.0% by weight of soft pitch as a binder to make the moisture content 10%,
It was pressurized and molded using a disc pelleter to form briquette charcoal.

This briquette was charged into a carbonization chamber maintained at 200°C in a direct heating carbonization furnace using combustion exhaust gas with an internal volume of 65JZ, and the temperature was raised to 900°C at a heating rate of 2.0°C/min to produce activated coke.

Results of measuring the SO2 adsorption amount of the generated activated coke 7
Although it was 2 mg/g, its mechanical strength was weak and it could not be used as activated coke.

Comparative Example 3 70.0% by weight of coal A finely pulverized to 74 μm and 18
Mix 6.0% by weight of stone powder finely ground to 0 μm,
After charging the coal into an electric furnace at 15°C and oxidizing the coal for 15 hours while blowing air, soft pitch 15°C was added as a binder.
After mixing 0% by weight to bring the moisture content to 10%, the mixture was pressure-molded using a disc beretter to obtain briquette charcoal.

This briquette was charged into a carbonization chamber maintained at 200°C in a direct heating carbonization furnace using combustion exhaust gas with an internal volume of 65°C, and the temperature was raised to 900'e at a heating rate of 2.0°C/min to form activated coke. Manufactured.

Results of measuring 502 adsorption amount of generated activated coke 6
5II1g/g and can be used sufficiently as activated coke, but it is necessary to lengthen the oxidation treatment time of the coal.
Not economical.

(Effects of the Invention) According to the present invention, activated coke having strong mechanical strength and high SO2 adsorption capacity can be produced at low cost.

representative person

Claims (1)

[Claims] It is characterized by blending 0.2% by weight or more and less than 30% by weight of wood pulverized to a particle size of 100 μm or less with finely pulverized coal, adding a binder, pressurizing it to form briquette charcoal, and then carbonizing it. A method for producing activated coke.