JPH01138292A - Treatment of collected coke powder in coke dry quencher - Google Patents

Abstract

PURPOSE:To obtain active coke having excellent absorptive capacity and excellent strength at low cost, by activating a collected coke powder in a circulated gas with steam while preheating it with the circulated gas before heat recovery. CONSTITUTION:About 20g/Nm<3> powder coke is contained in a circulated gas before the primary dust catcher of a coke dry quencher (CDQ), its temperature is about 900-1000 deg.C, and this dust is collected by collision against a collision plate 2. The collected coke powder 3 is discharged through a dust discharge pipe 4, and its temperature is lowered by the temperature of the ambient atmosphere. Therefore, it is kept at a temperature of about 900 deg.C which is the most suitable for activation by withdrawing part of a high-temperature circulated gas 5 after the primary dust catcher 1 and passing it through an external heater 6 around the chamber. A predetermined amount of the coke powder 3 kept at this temperature is withdrawn and activated by blowing low-pressure steam 9 from a waste heat boiler into it.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for treating coke powder generated from coke dry extinguishing equipment. More specifically, the present invention relates to a method for obtaining activated coke as a gas absorbing agent, soil improving agent, etc. from the collected coke.

[Conventional technology]

There are many wet or dry desulfurization and denitration processes for removing sulfur oxides and nitrogen oxides contained in various waste gases. Among these, in the dry method, granular or molded activated carbon is widely used as an adsorption-reducing agent due to its adsorption and 7f release performance. Furthermore, demand for activated carbon as a soil conditioner and plant growth promoter is increasing due to its characteristics as a porous carbon material.

Activated carbon has low strengths such as pressure resistance, abrasion resistance, and impact resistance, and is subject to economical problems due to large wear and tear when repeatedly used for adsorption and regeneration in moving bed or fluidized bed processes. Molded activated coke is attracting attention because it has a smaller specific surface area than activated carbon, but has higher strength and excellent desulfurization and denitrification abilities.

As a method for producing this activated coke, for example,
As shown in Publication No. 8-213614, a mixture containing 710% of coal and a binder as the main raw material for semi-formed coke produced from coal is molded, and the molded product is heated in a reducing atmosphere using an internally heated rotary kiln. There is a method for producing shaped activated coke for desulfurization and denitrification, which is carbonized under the coke and then activated.

On the other hand, a large amount of coke powder is generated from coke dry extinguishing equipment (hereinafter referred to as CDQ).

In other words, a fire extinguishing furnace with an internal cooling chamber and an external waste heat boiler are connected through a gas circulation circuit, and red-hot coke charged from the top is extinguished by inert circulating gas from the bottom, and the heat generated by the coke is extinguished. The system operates a waste heat boiler using circulating gas that has become hotter through exchange.
Since the circulating gas discharged from the fire furnace contains a large amount of coke powder, the circulating gas duct)K dust catcher
Multiple coke powder and cyclones are installed to collect and process coke powder.

As a method for treating coke powder in this CDQ, as shown in Japanese Patent Application Laid-Open No. 60-203693, there is a method in which coke powder collected by a dust collector is burned in a fluidized bed combustion facility. Problems to be Solved] In order to obtain activated coke with excellent adsorption performance and strength through activation, it is necessary to activate the raw coke source in a high-temperature atmosphere using water vapor, etc., which requires a large amount of thermal energy. . For this reason, it has the disadvantage of requiring a large amount of money for securing a heat source and equipment costs.

The present invention takes into consideration the fact that the coke powder recovered from the CDQ equipment can be recovered at high temperatures, and that the steam from the waste heat boiler in the CDQ equipment can be used directly for reuse, and the collected coke powder is effectively utilized. and K, which provides a method for obtaining activated coke with reduced equipment costs and running costs.

[Means and effects for solving the problems] The gist of the present invention is to activate coke powder in the collected circulating gas by preheating it to a predetermined temperature with the circulating gas before heat recovery, and then activating it with steam. This is a method for processing coke powder collected in coke dry extinguishing equipment to obtain coke.

The activation reaction between a carbon source and water vapor is generally carried out as shown in equation (1) below.

C+H, O→CO+H, -30-・・・・・・・・・
(1) The reaction mechanism is as follows.

C-)-H,02C(Hto)-...(2)(2
), water vapor is adsorbed on the surface of carbon, and the following (
3) Adsorbed water vapor releases hydrogen according to equation.

C(H,O)→H,+C(0) ・・・・・・・・・
(3) Next, plate layer oxygen is desorbed from the carbon surface as carbon monoxide as shown in equation (4).

C(0)→CO・・・・・・・・・(4) At that time(5)
A side reaction occurs as shown in Eq.

Co -1-HtO→CO, + H, + 9.65 k
d・−group・・・・(5) The reaction will finally be as shown in equation (6).

2H,0+C→2H,+CO,-20,35-...
...(6) The optimum activation temperature when coke powder is used as the raw material is around 900°C according to the experimental results shown in Fig. 2.

On the other hand, the temperature inside the primary dust catcher in the circulating gas duct on the exit side of the fire extinguishing tower of the CDQ equipment is around 900°C.

Therefore, if this sensible heat is used for the activation temperature, a heat source can be secured at low cost. In addition, reclaimed steam has the advantage that a heat source can be secured at a low cost by partially utilizing the steam generated by the waste heat boiler of the CDQ facility.

〔Example〕

The details of the invention will be explained in detail by means of exemplary embodiments shown in the drawings.

As shown in Fig. 1, approximately 20 r/Nrr? is contained in the circulating gas before the primary dust catcher 1 of the CDQ equipment. The coke powder is contained at a temperature of 900 to 1000°C, and is collided with a collision plate 2 to collect dust. The collected coke powder 3 is discharged from the dust discharge pipe 4, but the temperature decreases depending on the surrounding atmosphere temperature. Therefore, the primary dust catcher 1
A portion of the high-temperature circulating gas 5 is extracted and passed through the external heating container 6 of the chamber to a temperature of 900°C, which is optimal for activation.
was secured. To ensure this, compressed air 7 is blown in front of the primary dust catcher 1 using the ejector, and O!
The absorbed heat was compensated for in a self-circulating manner using the combustion heat generated by the combustion.

Low pressure steam 9 extracted from the waste heat boiler in the activation section 8 while discharging a predetermined amount of coke powder 3 maintained at this temperature.
The activation conditions were as follows: activation temperature was 800 to 950°C, amount of activation steam was 5 kg -8 team/scented coke powder, and activation time was 1.0 to 1, 2 hr. The coke powder 3 activated by activation is heated to 100°C by a water cooling pipe 10.
The coke was cooled to a temperature below and sieved to a predetermined particle size using a sieve 11 to obtain an activated coke product.

The activated coke thus obtained is SO.

It was used as an adsorbent. Adsorption capacity 30■-8O, /1-A
Conventionally, to obtain C activated coke, the amount of heat was 2.4
1 cl ka+g/Kf was required, but this was eliminated because the waste heat of CDQ was used by the method of the present invention.

〔Effect of the invention〕

As described above, according to the method of the present invention, it is now possible to produce activated coke using the waste heat of CDQ with inexpensive modified equipment, which was difficult to process due to the coke powder generated in large quantities compared to conventional CDQ. It has excellent effects that can be effectively used in many fields, such as as an adsorbent for air pollutants, odor components, etc., and as a soil conditioner.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a method for activating coke dust in a CDQ facility according to an embodiment of the present invention, and FIG. 2 is a diagram showing the relationship between activation temperature, SO, and adsorption capacity in an experiment. 1...Primary dust catcher-2...Collision plate 3...
- Coke powder 4... Dust discharge pipe 5... Circulating gas 6... External combustion type heating container 7... Compressed air 8... Activation part 9... Low pressure steam 10
...Water-cooled tube 11...Sieve. Figure 1 2 All of you 〒5=. , 10 ″ 11 9 , 11 + Figure 2 Activation temperature ['C] Primary dust catcher Collision plate Coke powder dust discharge pipe Circulating gas External combustion heating container Compressed air activation section/Low pressure steam Water cooling tube Sieve

Claims (1)

[Claims] A method for processing dust collected coke powder in a coke dry extinguishing equipment, in which activated coke is obtained by preheating coke powder in collected circulating gas to a predetermined temperature with circulating gas before heat recovery and then activating it with steam.