JP2002348111A - Activated carbon production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing high-strength activated carbon having high adsorption capacity, excellent desulfurization performance, and capable of withstanding circulating use in a moving bed type dry desulfurization and denitration process. SOLUTION: A semi-coke obtained by subjecting coal to low-temperature carbonization at a temperature of 300 to 600 ° C is used as a main raw material, and a coal having cohesive properties is used as an auxiliary raw material. In the method for producing activated carbon obtained by performing an activation treatment to obtain activated carbon, the amount of a mobile hydrogen component calculated from NMR measurement results at a temperature in a softened and molten state is 30% The following coal is used. Further, as the coking coal as an auxiliary raw material, a coal having a mobile hydrogen component amount of 35 to 45% calculated from NMR measurement results at a temperature in a softened and molten state is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing activated carbon having high strength and high adsorptivity used as an adsorbent in a dry desulfurization and denitration process.

[0002]

2. Description of the Related Art Various studies have been conducted to solve the drawbacks of activated carbon adsorbents. Desulfurization and denitration are performed by using coal as a raw material, adding a variety of binders to the mixture, forming the mixture under specific conditions, and then subjecting it to dry distillation and activation. Activated carbon suitable for the use has been proposed. For example, Japanese Patent Publication No. Sho 62-51885 discloses that a semi-active coke having a high activity is produced from coal, and this is used as a main raw material, and several kinds of coal and a binder are added to the coke to achieve a logarithmic index of 20 to 30%. Thus, a method of performing dry distillation and activation after adjusting the strength is disclosed. Japanese Patent Application Laid-Open No. 11-157822 discloses a method in which the blending of raw coal is adjusted to a button index of 1.5 to 4, followed by dry distillation and activation. However, these log index and button index are indexes indicating strength such as abrasion resistance, and index indicating caking property of blended coal. Activated carbon having excellent wear resistance and strength can be produced, but the desulfurization performance or desulfurization and denitration performance cannot always be improved.

[0003] Japanese Patent Application Laid-Open No. 11-349317 discloses a method for producing activated carbon having excellent strength and adsorptivity by blending coal having a volatile content and a fluidity within optimum ranges.
However, in this method, there are various restrictions on the manufacturing conditions such as the main raw material, the auxiliary raw material, the heating temperature, the heating rate, and the like, and it is difficult to obtain the main raw material and the auxiliary raw material with little component fluctuation, and the manufacturing process is complicated. However, there is a problem that activated carbon cannot be easily produced and the cost is increased.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems and has a high strength and a high adsorption capacity (for example, SO _x).
The present invention has been made to provide a method for producing activated carbon having excellent adsorption capacity, excellent desulfurization performance, and high strength enough to withstand circulation use in a moving bed type dry desulfurization and denitration process.

[0005]

Means for Solving the Problems As a result of intensive studies, the inventors have found that in a method for producing activated carbon for desulfurization or activated carbon for desulfurization and denitrification using coal as a raw material, NMR (nucleation) in the softening and melting temperature range of the coal is used. From the results of magnetic resonance (MRI) measurement, selecting and blending a component with a long transverse relaxation time present in the coal particles, that is, a coal with a specific range of the amount of mobile hydrogen component (melting index), provides extremely high desulfurization performance. Thus, a method for producing a high-strength and robust activated carbon having (e.g., SO _x adsorption ability) and capable of withstanding long-term use in a moving bed has been invented.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. According to the present invention, semi-coke obtained by subjecting coal to low-temperature carbonization at a temperature of 300 to 600 ° C. is used as a main raw material, and coal having caking properties is used as an auxiliary raw material. In a method of producing activated carbon by subjecting a molded product obtained by mixing and molding these materials together with a binder to heat treatment of activation and carbonization by activation heat treatment, NMR measurement at a temperature in a softened and molten state as raw carbon of semi-coke as a main raw material. The invention according to claim 1 is a method for producing activated carbon, characterized by using coal whose amount of a mobile hydrogen component calculated from the result is 30% or less. In the above-mentioned invention, as the coal having caking properties to be used as an auxiliary raw material, activated carbon using 35 to 45% of the amount of a mobile hydrogen component calculated from NMR measurement results at a temperature in a softened and molten state is used. The manufacturing method is the invention according to claim 2.

[0007]

According to the method for producing activated carbon of the present invention, as a raw material coal of semi-cured coke which is a main raw material, one having a mobile hydrogen component amount of 30% or less calculated from NMR measurement results at a softening melting temperature is used. Thereby, a large number of micropores having a diameter of about 10 ° suitable for adsorbing SO _x molecules can be formed, and thus the activated carbon produced therefrom has high strength and excellent SO _x adsorbing ability. In addition, as a raw material coal of a molded product which is a sub-material mixed with the semi-coke as described above which is a main material, the amount of a mobile hydrogen component calculated from NMR measurement results is
By using the caking property of coal is 35 to 45% can be produced activated carbon having a better SO _x adsorption capacity and good high logger strength appearance.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the flow chart of the embodiment shown in FIG. Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the examples. The amount of the mobile hydrogen component, the logarithmic strength, the desulfurization and denitration rate, and the powdering rate due to the production of ammonium sulfate were determined by the following measurements.

<Amount of mobile hydrogen component> A target coal sample is charged into a sample tube dedicated to a nuclear magnetic resonance apparatus. The size and shape of the coal sample are not particularly limited as long as the size is several millimeters or less, which is the size that enters the sample tube. As a measuring method, the pulse width of 90 ° hydrogen is 8 μsec, the echo time is 50 μsec to 3 msec, and the repetition time is 5 msec to 1 se.
c, The number of integration is 512 times. The data size is 512 points in the X direction, 512 points in the Y direction, and 1 to
Set to 512 points. At that time, the sample was heated at 3 ° C / min, and 89gauss was applied to each of the three axes of X, Y and Z.
The measurement is performed by applying a magnetic field gradient of s / cm, 96 gauss / cm, and 107 gauss / cm in a short time to obtain a hydrogen nucleus NMR imaging image of coal. By performing the same measurement while further raising the temperature, an NMR image image of the coal in a softened and molten state is obtained. From the obtained image, the distribution at an appropriate lateral relaxation time and the abundance of the mobile hydrogen component are calculated. Here, the abundance of the mobile hydrogen component depends on the transverse relaxation time of 10 in the softening and melting temperature range.
It means the amount of the component that is 0 μsec or more. The details of the multiple pulses and the transverse relaxation time are described in JP-A-11-326248.

<Logger strength> Activated carbon can be charged and discharged, and baffles with a height of 30 mm are installed at two locations on the diagonal of the cylinder.
30 g of an activated carbon sample was charged into a rotating cylinder (φ200 × 70), and the cylinder was rotated 1000 times at a rotation speed of 60 rpm. Thereafter, the activated carbon was taken out, fine powder was removed with a 3 mm mesh sieve, the weight ratio on the 3 mm sieve with respect to the input activated carbon weight was determined, and the logarithmic strength was determined by the following equation (1). The log strength tester is shown in FIG.

(Equation 1)

<SO _x adsorption capacity> Synthesis gas (SO ₂ vol%, O _{2 5} vol%, N ₂₎ was added to 10 cc of activated carbon sample whose particle diameter was adjusted to 1 to 3 mm.
83vol%, the H ₂ O 10vol%) at a flow rate of 3N liters / min 10
0 3 hours of contact at ℃ adsorbing the SO ₂ gas. afterwards,
Was heated for 1.5 hours a stream of N ₂ under 400 ° C., during which entrained and discharged into N _2, SO ₂ gas the total amount H ₂ O ₂ adsorbed in the previous operation
Absorb in 3% aqueous solution. (SO ₂ + H ₂ O ₂ → H ₂ SO ₄ , recovered as sulfuric acid) The absorption solution was arsenazo described in JIS K-0103.
The SO ₂ adsorption amount determined by neutralization titration with Method III SO
_x Adsorption capacity. Mg / g of SO ₂ adsorption amount per 1 g of activated carbon
Expressed in the unit of -ac. In addition, ac: activated carbon (activated carbon)
It is.

<Denitration rate> A cylindrical column having a diameter of 50 (a denitration test reaction vessel) is filled with 170 cc of activated carbon and heated to 90 ° C. Syngas (SO ₂ 135 ppm, NO 160 ppm, NH ₃ 450 ppm,
O ₂ 10%, H ₂ O 10%, remaining N ₂ ) are heated to 90 ° C. and brought into contact with the activated carbon packed bed at a flow rate of 2 N l / min. After the synthesis gas was aerated for 20 hours, the NO concentrations on the inlet and outlet sides of the activated carbon packed bed were measured, and the denitration rate was determined by the following equation (2).

(Equation 2)

<Powderation rate due to production of ammonium sulfate> A cylindrical column (reaction vessel for denitration test) having a diameter of φ50 is filled with 170 cc of activated carbon and heated to 90 ° C. Syngas (SO ₂ 135ppm, NO 160ppm
, NH ₃ 450 ppm, O ₂ 10%, H ₂ O 10%, and the remaining N ₂ ) are brought into contact with the activated carbon packed bed at a flow rate of 2 Nl / min. After syngas is aerated for 100 hours, the entire amount of activated carbon is extracted from the cylindrical column, impregnated with water in a beaker, and gently stirred. Next, the mixture is filtered through a 1 mm wire mesh to separate the filtrate (including activated carbon fines) and activated carbon pellets. Activated carbon fine powder is further extracted from the filtrate by filtration, dried and weighed to obtain the activated carbon fine powder weight. The activated carbon pellets are heated under a stream of N ₂ at 400 ° C. for 1.5 hours, subjected to a regeneration treatment, and then weighed to obtain the total weight of the activated carbon pellets after regeneration. The weight of the activated carbon fine powder and the weight of the activated carbon pellet after regeneration are summed up to obtain the total weight of activated carbon after regeneration. The regenerated activated carbon pellets were sieved through a 3 mm sieve, the weight under the sieve and the weight of the activated carbon fine powder were totaled, and the weight was determined as -3 mm. FIG. 8 shows an apparatus for measuring the denitration rate and the powdering rate due to the production of ammonium sulfate.

(Equation 3)

In FIG. 1, reference numeral 1 denotes a coal which is subjected to low-temperature dry distillation to be used as a raw coal of semi-coke as a main raw material. This coal is obtained from NMR measurement results at a temperature corresponding to the softening and melting temperature range. Calculated mobile hydrogen content is 30%
Or less, preferably 15% or more and 30% or less. The amount of the mobile hydrogen component calculated from the result of NMR measurement at a temperature corresponding to the softening and melting temperature range is set to the above-mentioned range, because the content of the mobile hydrogen component exceeding 30% has an effect on the adsorption of SO _x molecules. This is because the micropore volume in the vicinity of 10 mm in diameter, which exerts the effect of the above, is reduced, while the effect of improving the SO _x adsorption capacity is saturated even if it is less than 15%, so that a large improvement cannot be expected.

The coal 1 is charged into the low-temperature carbonization furnace 2 and charged to 6%
At an oxygen concentration of not more than 300 ° C and not more than 600 ° C, preferably 4 ° C
In a heating atmosphere of 00 ° C or more and 550 ° C or less, the residence time in the heating section in the furnace is 15 minutes or more and 120 minutes or less, preferably 25 minutes or more.
Semi-coke is obtained by low-temperature carbonization under conditions of 80 minutes or less. The reason why the low-temperature carbonization conditions are as described above is that if the temperature of the heating atmosphere is 300 ° C or less, or the residence time in the furnace is 15 minutes or less, it is sufficient to form a pore structure to be supported as semi-coke. As a result, semi-coke with a poor pore structure, in which only water of crystallization and only a small amount of volatiles have volatilized, is mainly used. if you try to production of the activated carbon as a raw material, the activation reaction of the activated gas such as steam in the activation process does not progress sufficiently, the adsorption capacity of the sO _x poor activated carbon obtained only, - how the temperature of the heating atmosphere 600 Over ℃,
Alternatively, when the residence time in the furnace is 120 minutes or more, the disappearance of volatiles sufficient for forming the pore structure proceeds, but the graphitization of the substrate of semi-coke itself proceeds excessively. Since graphite crystals have a stable structure in which the constituent carbon atoms are regularly arranged, if they are present in a large amount in activated carbon, not only the adsorption capacity of SO _x but also the catalytic activity for denitration will be significantly reduced.

The semi-coke used as the main raw material is
Activated carbon, which becomes a product due to pores and some residual caking
SO_xSemi-coke to determine the adsorption capacity and strength of
The selection of coal as a raw material for
Become. High SO as activated carbon _xTo maintain adsorption capacity
Is SO2 in the state of semi-coke used as a main raw material._xMinute
Many pores with pore sizes suitable for adsorbing particles are formed.
Is desirable. Table 1 shows 16 types with different degrees of coalification.
Coal at a temperature corresponding to the softening and melting temperature range.
Shows the amount of mobile hydrogen component calculated from NMR measurement results
You. The softening and melting temperature of the target coal was 350 ° C.
The temperature range was 510 ° C.

The amount of the mobile hydrogen component calculated from the NMR measurement results of the caking coal blended as an auxiliary material is 35 to 45.
% Is desirable. The reason is that the amount of mobile hydrogen
When less than 35% of coal is used as an auxiliary material, the appearance of the obtained activated carbon is good, but the logarithmic strength is greatly reduced, while the amount of mobile hydrogen component exceeds 45% When coal is used as an auxiliary raw material, the obtained activated carbon swells due to excessive caking and cracks occur, and a large number of pores having a large pore size are formed inside, thereby lowering the logarithmic strength.

[0018]

[Table 1]

FIG. 2 shows an example of the measurement results of the pore size distribution of semi-coke produced by heating the above 16 types of coal at 450 ° C. for 60 minutes. As a result of measuring the pore size distribution of the produced semi-coke, the coal can be classified into four types, A, B, C, and D, based on the degree of development of the pore volume where the pore size is around 10 °. In other words, in semi-coke produced from coal belonging to Class A where the amount of mobile hydrogen component is 30% or less,
For semi-coke produced from coal belonging to the B, C, and D classes where the amount of mobile hydrogen components exceeds 30%, it has a structure in which the micropore volume around 10 mm in diameter has developed specifically under the same heating conditions. . In addition, in semi-coke produced from coal belonging to the B, C, and D classes, as the amount of the mobile hydrogen component increases, the micropore volume around 10 mm in diameter decreases. No swelling or swelling is seen in the B class,
In the cases of the C class and the D class, remarkable swelling occurs, and the fractured surface of the semi-coke has coarse pores as well as a large number of coarse pores due to the swelling and expansion of the semi-coke appearance. In particular, in the case of the D region, the coal particles swell so that the original shape of the coal is not stopped, and the particles are strongly welded to each other.
This is an operational problem for producing activated carbon.

Next, FIG. 3 shows the measurement results of the heating time and the SO _x adsorption capacity of the semi-coke produced when low-temperature carbonization was performed at 450 ° C. According to this result, semi-coke produced from coal belonging to Class A has the highest SO _x adsorption capacity, and as the amount of mobile hydrogen component in coal increases, SO
The adsorption capacity of _x decreases. That is, in order to effectively increase the SO _x adsorption capacity in the semi-coke used as the main raw material, it is necessary to increase the micropore volume around 10 mm in diameter as much as possible. It is preferable to use, as a main raw material, semi-coke obtained by performing low-temperature carbonization on coal belonging to the region A in which the amount of the mobile hydrogen component determined from the NMR measurement results is 30% or less.

This semi-coke is used as a main raw material in a pulverizer 3
And pulverize. In addition, the caking coal 4 used as an auxiliary material is also charged into the pulverizer 3 and pulverized. Next, the crushed semi-coke as the main raw material and the caking coal 4 as the auxiliary raw material are mixed.
9: 1 to 5: 5 ratio, preferably 8: 2 to 6: 4
At a ratio of 2 to obtain mixed and pulverized particles. The mixed and pulverized particles are transferred to a kneader 7, in which, in addition to coal or petroleum heavy oil such as tar and pitch as a binder 5, pulp production waste liquid, and the like, a molding aid 6 is added and kneaded. I do. The kneaded product is introduced into a molding machine 8 to have a diameter of 5 to 20φ and a length of 5 to
Each of the formed particles is quantitatively charged into a carbonization activation furnace 9 such as a rotary kiln, and steam 10 and nitrogen gas 11 are added so that the activation proceeds effectively. Meanwhile, by carbonizing and activating at a temperature of 750 to 900 ° C., it is possible to produce a product 12, that is, activated carbon having high strength and high desulfurization and denitration ability.

FIG. 4 shows the relationship between the added amount of auxiliary raw coal mixed with the main raw material and the logarithmic strength. Here, semi-coke, the main raw material, was obtained by heating coal 1 of brand A belonging to area A to 450 ° C.
For 60 minutes. Activated carbon that uses cohesive coals that belong to the A and B regions as admixed raw materials has good appearance, no cracks due to swelling or expansion, good product shape, and narrow particle size distribution. Although it is a configuration, the logger strength is a value significantly lower than that of ready-made activated carbon. In addition, in the activated carbon in which the caking coal blended as an auxiliary material belongs to the D region, swelling due to excessive caking occurs, a large number of pores are formed in the internal fracture surface, and the logarithmic strength is reduced. It will be a lower value. -Way,
In activated carbon using caking coal to be blended as an auxiliary material belonging to the C region, the mixing ratio of semi-coke as a main material and caking coal as an auxiliary material is in the range of 9: 1 to 5: 5. An activated carbon having a good product shape, a narrow particle size distribution, and a logarithmic strength higher than that of ready-made activated carbon is obtained without generation of cracks due to swelling or expansion. In other words, when obtaining a robust activated carbon, the amount of the mobile hydrogen component calculated from the NMR measurement results at a temperature corresponding to the softening and melting temperature range is 35%.
It is important to select caking coal within the range of 45% or less as an auxiliary material.

[0023]

EXAMPLES together with comparative examples the relation between specific surface area and SO _x adsorption capacity of the activated carbon produced by the method shown in FIG. Table 1
Of the 16 types of coal with different amounts of mobile hydrogen components shown in
Activated carbon was produced using semi-coke obtained as a main raw material by performing low-temperature carbonization on six types of coal belonging to region A in which the amount of mobile hydrogen components was 30% or less. Particle size 50 of coal belonging to area A
coarsely pulverized to less than 2 mm, guided to an externally heated rotary kiln, dry-dried to obtain a semi-coke with an oxygen concentration of 2% or less, a heating atmosphere temperature of 450 ° C, and a residence time of 60 minutes in the furnace. The formed coke was pulverized by the pulverizer 3 to obtain a main raw material. At this time, the melting index of the mobile hydrogen component was 40.2 among the 16 types of coal having different mobile hydrogen components shown in Table 1.
% Of bituminous coal is pulverized by the pulverizer 3 to obtain an auxiliary material. A mixture of the main raw material and the auxiliary raw material in a mass ratio of 8: 2, and soft coal pitch as a binder 5 was used.
20% by mass and 15% by mass of water as a molding aid 6 were added, and the mixture was sufficiently kneaded by a kneader 7 and formed into a columnar shape having a diameter of 10φ and a length of 10 mm by an extruder 8. The molded product is guided to an external heating type tally kiln, and the maximum temperature of the molded product is 830 ° C and the average heating rate is 1% in an atmosphere with an oxygen concentration of 1% and an activated steam injection rate of 1.0 kg per kg of the molded product. 18 ℃ / mi
Activated carbon was manufactured by heating at a temperature of 800 ° C or higher for 40 min, carbonizing and activating. The activated carbon thus obtained has a logarithmic strength of 97.9 to 98.8.
% SO _x adsorption capacity 72.0~80.2mg / g-ac, denitrification rate 48%, was very good as powdering rate of 0.01% and desulfurization and denitration active carbon with ammonium sulfate product.

Comparative Example 1 Of the 16 types of coal having different amounts of mobile hydrogen components shown in Table 1, the amount of mobile hydrogen components was 30
% Of the coal belonging to the region B, which is more than 35% and less than 35%, was subjected to low-temperature carbonization, and activated carbon was produced using semi-coke obtained as a main raw material. Coal belonging to the B area is coarsely pulverized to a particle size of 50 mm or less and led to an externally heated rotary kiln.
2% or less, heating atmosphere temperature is 450 ℃, residence time in furnace
Semi-coke was obtained by dry distillation for 60 minutes, and then this semi-coke was pulverized by the pulverizer 3 to obtain a main raw material. In addition, at this time, coal 16 having different mobile hydrogen components shown in Table 1 was used.
Among the seeds, bituminous coal containing a mobile hydrogen component having a melting index of 40.2% was pulverized by a pulverizer as an auxiliary material. To a blended coal obtained by blending these main raw materials and sub-raw materials in a mass ratio of 8: 2, coal-based soft pitch was used as a binder 5 in an amount of 20% by mass relative to the blended coal, and water was used as a forming aid 6 in a water-soluble mixture. Mass%,
The mixture sufficiently kneaded by the kneading machine 7 was formed into a cylindrical shape having a diameter of 10φ and a length of 10 mm by the extrusion molding machine 8. The molded product is guided to an externally heated rotary kiln, and the maximum temperature of the molded product is 830 ° C. and the average heating rate is 1 in an atmosphere with an oxygen concentration of 1% and an activated steam blowing rate of 1.0 kg / kg of the molded product.
Activated carbon was manufactured by heating at 8 ° C / min and at a holding time of 800 ° C or more for 40min, carbonizing and activating. The activated carbon thus obtained has a logarithmic strength of 97.1.
9898.2%, but the SO _x adsorption capacity was 45.5-47.O.
mg / g-ac, denitration rate 38%, powdering rate due to production of ammonium sulfate 0.9%, which were remarkably inferior to the examples.

Comparative Example 2 Of the 16 types of coal having different amounts of mobile hydrogen components shown in Table 1, the amount of mobile hydrogen components was 35
Activated carbon was produced using semi-coke obtained as a main raw material by performing low-temperature carbonization on six types of coal belonging to the C region of not less than 45% and not more than 45%. Coal belonging to area C is coarsely pulverized to a particle size of 50 mm or less and guided to an externally heated tally kiln, where the oxygen concentration is 2% or less, the heating atmosphere temperature is 450 ° C, and the carbonization time is 60 minutes in the furnace. The semi-coke was then pulverized with a pulverizer to obtain a main raw material. At this time, of the 16 types of coal having different mobile hydrogen components shown in Table 1, bituminous coal having a melting index of the mobile hydrogen component of 40.2% was pulverized by a pulverizer to be used as an auxiliary material. . A coal-based soft pitch as a binder 5 was added to the blended coal in which the main raw material and the auxiliary raw material were blended in a weight ratio of 8: 2 to the blended coal.
Mass%, water as shaping aid 6 15 mass% based on coal blend
The mixture was kneaded sufficiently by a kneader 7 and extruded into a round shape having a diameter of 10φ and a length of 10 mm by an extruder 8. This molded product is guided to an externally heated rotary kiln, where the oxygen concentration is 1
%, The maximum steam temperature of the molded product is 830 ° C, the average temperature rise rate is 18 ° C / min, and the holding time at 800 ° C or more is 40min in an atmosphere where the amount of activated steam blown is 1.0kg per kg of the molded product. Activated carbon was produced by heating, carbonizing and activating. The activated carbon thus obtained has a logarithmic strength
From 92.0 to 94.8% SO _x adsorption capacity 33.0~36.Omg / g-ac, denitrification rate 38%, a powdering ratio of 1.2% with ammonium sulfate product, be those significantly inferior relative also Example either performance Was.

Comparative Example 3 Of the 16 types of coal having different amounts of mobile hydrogen components shown in Table 1, the amount of mobile hydrogen components was 45%.
% Activated carbon was produced by using semi-coke obtained as a main raw material by performing low-temperature carbonization on three types of coal belonging to the D region exceeding 3%.
Coal belonging to area D is coarsely pulverized to a particle size of 50 mm or less, and guided to an externally heated rotary kiln, and carbonized so that the oxygen concentration is 2% or less, the heating atmosphere temperature is 450 ° C, and the residence time in the furnace is 60 minutes. After the semi-coke was formed, the semi-coke was pulverized by a pulverizer to obtain a main raw material. At this time, of the 16 types of coal having different mobile hydrogen components shown in Table 1, bituminous coal having a melting index of the mobile hydrogen component of 40.2% was pulverized by the pulverizer 3 and used as an auxiliary material. did. In a coal blend in which the main raw material and the auxiliary raw material were blended in a weight ratio of 8: 2, 20 wt% of coal-based soft pitch was used as a binder 5 with respect to the coal blend, and 15 wt% of water was used as a forming aid 6 with respect to the coal blend. % And kneaded sufficiently with a kneading machine 7 to form a cylinder having a diameter of 10φ and a length of 10 mm by an extrusion molding machine 8. This molded product is guided to an externally heated tally kiln, and the oxygen concentration is 1% and the amount of activated steam blown is
Maximum temperature of the molded product in an atmosphere of 1.0 kg per 1 kg
Activated carbon was produced by heating at 830 ° C., an average heating rate of 18 ° C./min, and a holding time at 800 ° C. or higher of 40 min, carbonizing and activating. Activated carbon thus obtained is, logger strength from 90.2 to 92.1%, the SO _x adsorption capacity 10.8
~ 12.0mg / g-ac, denitration rate 5%, powdering rate 1.0 due to ammonium sulfate formation
%, All of which were significantly inferior to the examples.

FIG. 5 shows an improvement in the SO _x adsorption capacity due to an increase in the specific surface area due to the formation of micropores. The activated carbon produced from coal in the region A having a large specific surface area has a high desulfurization performance. I understand. As shown in FIG. 6, such a specific surface area greatly varies depending on the temperature of the heating atmosphere in low-temperature carbonization, so that it is desired to appropriately set the carbonization temperature.

[0028]

As described above, according to the method for producing activated carbon of the present invention, as a coal which is subjected to low-temperature carbonization to form a semi-coke as a main raw material, it can be easily calculated from NMR measurement results at a softening melting temperature. By using an element having a hydrogen content of 30% or less, a diameter 10 suitable for adsorbing SO _x molecules can be obtained.
A large number of micropores near Å can be formed, and the activated carbon produced therefrom can have high strength and excellent desulfurization performance (eg, SO _x adsorption capability). In addition, by using a caking coal having a mobile hydrogen component amount of 35 to 45% calculated from NMR measurement results as a secondary raw material mixed with semi-coke as a main raw material, the appearance is further improved and high. Activated carbon having logarithmic strength, good desulfurization (SO _x adsorption ability) performance, and low powdering rate due to low ammonium sulfate production can be produced. Further, an excellent activated carbon for desulfurization and denitration can be obtained.

[Brief description of the drawings]

FIG. 1 is a flowchart of a process for producing activated carbon.

FIG. 2 is an explanatory diagram showing the volume distribution of micropores of four types of coal classified according to the amount of mobile hydrogen components.

FIG. 3 is a diagram showing the relationship between the low-temperature carbonization time and the SO _x adsorption capacity of semi-coke.

FIG. 4 is a graph showing the relationship between the type and blending ratio of coal having cohesiveness as an auxiliary raw material and logarithmic strength.

FIG. 5 is a graph showing the relationship between the type of raw coal and the specific surface area of semi-coke as a main raw material, and the improvement of the SO _x adsorption ability by increasing the specific surface area.

FIG. 6 is a relationship diagram showing a change in specific surface area of activated carbon depending on the temperature of low-temperature carbonization.

FIG. 7 is an explanatory diagram of a logger strength tester.

FIG. 8 is an explanatory diagram showing a method for measuring a denitration rate and a powdering rate due to production of ammonium sulfate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Coal used as semi-coke 2 Low temperature carbonization furnace 3 Crusher 4 Caking coal 5 Binder 6 Molding aid 7 Kneader 8 Molding machine 9 Carbonization and activation furnace 10 Steam 11 Nitrogen gas 12 Product

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B01D 53/81 B01D 53/34 ZAB 4H012 53/94 132Z B01J 20/20 53/36 102F 20/30 C04B 35 / 52 A C04B 35/52 C10B 57/04 (72) Inventor Hisao Kamiyama 5-3 Tokai-cho, Tokai-shi, Aichi Pref. Inside Nagoya Works, Nippon Steel Corporation (72) Inventor Koji Saito, Kawasaki-shi, Kanagawa 3-35-1, Ida, Nakahara-ku New Nippon Steel Corporation Technology Development Division (72) Inventor Seita Kinoshita 3-1-3 Kotobukicho, Muroran-shi, Hokkaido Taihei Kogyo Co., Ltd. Muroran Branch (72) Inventor Naka Yoshinori Ma 52-5 Marune, Arao-cho, Tokai-shi, Aichi Prefecture Taihei Kogyo Co., Ltd. (72) Inventor Norimichi Takahashi 52-5 Marune, Arao-cho, Tokai-shi, Aichi Prefecture Taihei Kogyo Co., Ltd. F term in the Tokai branch of the company (reference) 4D002 AA02 AA12 BA03 DA41 HA01 4D048 AA02 AA06 BA05X BB01 CC41 EA04 4G032 AA02 BA00 GA01 4G046 HA05 HB02 HC16 4G066 AA04D AA05B AC08A AC08D CA23 CA28 DA02 FA18 FA23 FA01 FA01

Claims (2)

[Claims] (1) A semi-coke obtained by subjecting coal to low-temperature carbonization at a temperature of 300 to 600 ° C. as a main raw material, a coal having cohesiveness as a sub-raw material, and carbonization into a molded product obtained by mixing and forming these with a binder. In the method for producing activated carbon obtained by performing an activation treatment to obtain activated carbon, the amount of a mobile hydrogen component calculated from NMR measurement results at a temperature in a softened and molten state is 30 as raw coal of semi-coke as a main raw material. % Of activated carbon. 2. A coal having 35 to 45% of a mobile hydrogen component calculated from NMR measurement results at a temperature in a softened and molten state as a coal having caking properties as an auxiliary raw material. 2. The method for producing activated carbon according to 1.