JP2007063027A - Method for reducing organic chlorinated compound in exhaust gas of cement manufacture plant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for reducing an organic chlorinated compound in an exhaust gas of a cement manufacture plant, which can reduce the quantity of the discharged organic chlorinated compound, such as dioxins and PCBs, discharged from the cement manufacture plant, and can save fuel as well. <P>SOLUTION: The powder containing the organic chlorinated compound, such as the dioxins and PCBs, is brought into contact with a high temperature gas of ≥100°C within the cement manufacture plant to separate or thermally decompose the organic chlorinated compound. The powder is then filtered to adsorb the organic chlorinated compound in the high temperature gas on the adsorption powder. Then, the adsorption powder is used as a part of the firing fuel of clinker, thereby thermally decomposing the adsorbed organic chlorinated compound. Consequently, the quantity of the discharged organic chlorinated compound discharged from the cement manufacture plant can be further reduced. Even more, the firing fuel can be saved. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a method for reducing organochlorine compounds in exhaust gas from a cement production facility, and more particularly to a technique for adsorbing and thermally decomposing organochlorine compounds such as dioxins and PCBs emitted from a cement production facility and reducing the emission amount. .

Dioxins (PCDDs) are abbreviations of poly chloro dibenzo-p-dioxin and are a kind of organic chlorine compounds. Poly chloro dibenzofuran (PCDFs) is known as an analog of this dioxin.
In particular, it belongs to Tetra chloro dibenzo-p-dioxin, which is a tetrachloride of PCDDs (T4CDDs), and has chlorine at positions 2, 3, 7, 8 3,7,8-T4CDD is highly toxic.
The 2,3,7,8-tetrachloro form is obtained as a by-product in the production of trichlorophenol, 2,4,5-trichlorophenoxyacetic acid, and is obtained by chlorination of dibenzo-P-dioxin. The melting point is 306-307 ° C.

  Further, as another organic chlorine compound that is harmful to the human body, for example, PCB (polychlorinated biphenyl) is known. PCB is excellent in chemical stability, insulation, nonflammability, and adhesiveness, and has been used as an insulating oil for transformers and capacitors mounted in electric facilities such as power plants, railways, and buildings. However, it contains a coplanar PCB that has the same toxicity as dioxin. Therefore, in 1974, the law prohibits the manufacture, distribution and new use of PCBs.

  Examples of the PCB treatment method include an incineration treatment method in which PCB is heat-treated at a high temperature, a dechlorination decomposition method in which PCB is dechlorinated, and a supercritical water in which PCB is decomposed into carbon dioxide and water. A critical hydrolytic decomposition method has been developed. Of these, incineration methods are concerned that dioxins are synthesized when the heat treatment gas of PCB is cooled.

Thus, for example, Patent Document 1 and Patent Document 2 are known as conventional techniques for solving these problems.
Patent Document 1 supplies exhaust gas from a cement production facility to a dust collector, collects dust collection dust containing an organic chlorine compound, and collects at least a part of the collected dust collection dust at 800 ° C. or higher in the cement production facility. This shows a method of putting it in the high temperature part. Since dioxins are thermally decomposed at around 800 ° C., this method can efficiently decompose and detoxify dioxins.
In addition, a small amount of the vaporized organochlorine compound is contained in the dedusted gas discharged from the dust collector and released to the atmosphere from the flue. As a countermeasure against this, Patent Document 1 describes a method of reducing the dioxin concentration in the dedusted gas. This is a method in which exhaust gas is drawn from a point (low temperature part) having a temperature of 30 to 400 ° C. in a cement manufacturing facility and supplied to a dust collector. That is, in the exhaust gas derived from the low temperature part, the organic chlorine compound is concentrated (low temperature concentration) compared to the exhaust gas from the high temperature part of the cement manufacturing facility. As a result, the concentration of dioxins in the dust removal gas decreases if the dust collection dust having a high organochlorine compound concentration is removed by the dust collection treatment.

In Patent Document 2, a PCB-containing material carried from the outside to a cement factory is put into a rotary kiln, and this is heated by heat (1000 ° C. or higher) when firing a cement clinker, and the PCB is thermally decomposed. A method is shown in which exhaust gas generated during pyrolysis is led out of the rotary kiln and then rapidly cooled at a cooling rate of 20 ° C./second or more. By cooling the exhaust gas at 20 ° C./second or more, the exhaust gas passes through a temperature range in which the amount of dioxins synthesized increases in a short time. As a result, PCB can be decomposed while preventing the generation of dioxins.
JP 2004-244308 A JP 2002-147722 A

  Thus, according to Patent Document 1, at least a part of the dust collected by passing the exhaust gas through the dust collector is put into a high temperature part of a cement manufacturing facility that is 800 ° C. or higher during normal operation, and the dust is collected. Dioxins adsorbed by dust were pyrolyzed. At that time, as a measure against organochlorine compounds in the dedusted gas (dust collector passing gas) released from the flue to the atmosphere, the exhaust gas is drawn out from the point where the temperature is 30 to 400 ° C. (low temperature part) in the cement production facility, The method of supplying this to a dust collector was adopted. However, with this measure, dioxins discharged from the cement production facility could not be reduced sufficiently.

  On the other hand, Patent Document 2 is to thermally decompose a PCB-containing material carried from outside (external) of a cement manufacturing facility by heating to 1000 ° C. or higher in a rotary kiln. However, this method could not remove PCB generated in the cement production facility.

  Therefore, as a result of earnest research, the inventor firstly used a powder (such as dust collection dust) that is present in a cement production facility and contains an organic chlorine compound such as dioxins and PCB at 100 ° C. in the cement production facility. The organochlorine compound is separated (vaporized) or decomposed from the powder by contacting with the above high-temperature gas. Next, the separated high-temperature gas containing the organochlorine compound is adsorbed on the adsorbent powder having the function of adsorbing the organochlorine compound, and the adsorbed adsorbed powder is used as a calcined fuel. By decomposing chlorine compounds, it is possible to further reduce the amount of dioxins emitted from cement production facilities and organic chlorine compounds such as PCBs, and to save fuel for firing. We have found that this is possible and have completed this invention.

  This invention can reduce the discharge amount of organic chlorine compounds such as dioxins and PCBs discharged from a cement manufacturing facility, and can reduce the amount of organic chlorine compounds in the exhaust gas of a cement manufacturing facility that can save fuel. The object is to provide a method and its cement production equipment.

  The invention according to claim 1, in a cement production facility for firing cement clinker from a cement raw material, a powder containing an organic chlorine compound is brought into contact with a high-temperature gas at 100 ° C. or higher in the cement production facility, Organic substance removing step for separating or decomposing organic chlorine compound from powder, and powder removing step for collecting and removing powder from which organic chlorine compound is separated or decomposed from high temperature gas in contact with said powder An organic substance adsorption step in which the powder is removed and the high temperature gas containing the organochlorine compound is brought into contact with the adsorbent powder to adsorb the organochlorine compound to the adsorbent powder; and the adsorbent powder in which the organochlorine compound is adsorbed And a decomposition step of decomposing the organochlorine compound adsorbed on the adsorbed powder by using as a fuel for firing the cement clinker Organic chlorine compounds in the exhaust gas of the granulation equipment which is reduction method.

According to invention of Claim 1, the powder which exists in cement manufacturing facilities and contains organic chlorine compounds, such as dioxins and PCB, is made to contact high temperature gas which becomes 100 degreeC or more in cement manufacturing facilities. . Thereby, the organic chlorine compound is separated (vaporized) from the powder, or the organic chlorine compound is decomposed (organic matter removing step).
Thereafter, the powder from which the organochlorine compound has been separated or decomposed is removed by collection from the high-temperature gas in contact with the powder (powder removal step). Then, the high-temperature gas thus separated is brought into contact with the adsorbent powder, and the organic chlorine compound in the high-temperature gas is adsorbed onto the adsorbent powder (organic substance adsorption step). Next, the adsorbed powder adsorbing the organic chlorine compound is used as a baked fuel, and the organic chlorine compound adsorbed on the adsorbed powder is decomposed (decomposition step).
Thereby, the discharge | release amount of organochlorine compounds, such as dioxins and PCB which are discharged | emitted from a cement manufacturing facility, can be reduced more. In addition, fuel for firing can be saved.

  As the organic chlorine compound, for example, residual organic chlorine compounds represented by dioxins (including precursors), PCB and the like can be employed.

The separation temperature of the dioxins from the powder is 100 ° C. or higher. The decomposition temperature of dioxins is 800 ° C. or higher. The separation temperature of the PCB from the powder is 100 ° C. or higher. The decomposition temperature of PCB is 800 ° C. or higher.
The adsorbed powder is not limited as long as it is a powder capable of adsorbing dioxins in exhaust gas and organochlorine compounds such as PCB. However, a porous powder having high adsorptivity of the organic chlorine compound is preferable. For example, coal fine powder, oil coke fine powder, activated carbon fine powder and the like can be employed.
The larger the BET specific surface area, the better the adsorbed powder. If it is less than 0.1 m ² / g, realistic adsorption performance cannot be obtained. Using an adsorbent powder having a large BET specific surface area can reduce the burden on the dust collector.

As the high-temperature gas, for example, when the cement production facility has a rotary kiln and a preheater, exhaust gas (250 to 400 ° C.) discharged from the top of the preheater during firing can be employed. In addition, the exhaust gas (250-1000 degreeC) etc. which are discharged | emitted from a clinker cooler can be employ | adopted.
The larger the amount of adsorbed powder supplied to the hot gas, the better. However, if the amount is too large, the burden on the dust removal equipment increases. It changes according to the BET specific surface area of adsorption powder so that it may become below the expected density | concentration.

The temperature of the hot gas is not limited as long as it is 100 ° C. or higher. If it is less than 100 ° C., the organic chlorine compound does not scatter. Considering the efficiency, 200 ° C. or higher is preferable.
The method for bringing the adsorbed powder into contact with the hot gas is not limited. For example, a method of forming an inlet for adsorbed powder in the middle of a hot gas pipe can be employed. As the adsorbed powder feeder, a screw feeder or the like can be employed.
As the cement manufacturing facility, for example, a rotary kiln using a firing device can be employed. Moreover, you may employ | adopt the thing which has a preheater, a calcining furnace, and a rotary kiln. However, the cement manufacturing facility is not limited to these structures.

As a method for collecting powder from high-temperature gas, for example, collection by a dust collector can be employed. As a dust collector here, an electric dust collector, a bag filter, etc. are employable, for example.
As a method of using the adsorbed powder on which the organochlorine compound is adsorbed as fuel for firing the cement clinker, for example, it can be introduced from the fuel inlet of the combustion burner as the fuel for the combustion burner of the rotary kiln. In this case, the organic chlorine compound is instantaneously decomposed by the heat of the burner frame (1500 ° C. or higher).

The invention according to claim 2 is characterized in that the powder is dust collection dust collected by a dust collector in the cement manufacturing facility, and the organic matter in the exhaust gas of the cement manufacturing facility according to claim 1 This is a chlorine compound reduction method.
As the dust collector, for example, an electric dust collector or a bag filter can be employed.
The dust collection dust used here may be all or a part of the dust collection dust discharged from the dust collector.

  According to a third aspect of the present invention, in any one of the second and third aspects, the high-temperature gas is an exhaust gas discharged from an upper portion of a preheater when the cement clinker is fired. It is an organic chlorine compound reduction method in the exhaust gas of the described cement manufacturing equipment.

  According to invention of Claim 3, the powder containing an organic chlorine compound is made to contact the waste gas (250-400 degreeC) discharged | emitted from the upper part of the preheater. Thereby, the organochlorine compound adsorbed on the powder can be separated from the powder or decomposed.

  The invention according to claim 4 is characterized in that the adsorbed powder is one of coal fine powder and oil coke fine powder which are fuels for burning the cement clinker. It is an organochlorine compound reduction method in the exhaust gas of the cement manufacturing equipment of any one of Claim 3.

The adsorbed powder may be fine coal powder or fine oil coke powder. Further, both fine coal powder and fine oil coke powder may be used.
The larger the BET specific surface area of the fine coal powder, the better. If it is less than 0.1 m ² / g, realistic adsorption performance cannot be obtained.
The larger the BET specific surface area of the oil coke fine powder, the better. If it is less than 0.1 m ² / g, realistic adsorption performance cannot be obtained.

  The invention described in claim 5 is characterized in that the powder removed in the powder removing step is put into a raw material mill for pulverizing the cement raw material for firing. The method for reducing organochlorine compounds in the exhaust gas of a cement production facility according to any one of the above.

  According to the invention described in claim 5, the organic chlorine compound is removed and the powder collected from the high temperature gas is put into the raw material mill and becomes a part of the cement raw material. Thereby, the saving of a cement raw material can be aimed at.

  According to the invention described in claim 1, the powder containing the organic chlorine compound such as dioxins and PCB is brought into contact with a high-temperature gas at 100 ° C. or higher in the cement production facility, and the organic chlorine compound is removed from the powder. Separate or pyrolyze. Thereafter, the powder is removed from the high-temperature gas by collection, and then the high-temperature gas containing the organic chlorine compound is brought into contact with the adsorbent powder to adsorb the organic chlorine compound to the adsorbent powder. And the organochlorine compound adsorbed by the adsorbent powder is thermally decomposed by using the adsorbent powder containing the organochlorine compound as a part of the cement clinker firing fuel. As a result, it is possible to further reduce the discharge amount of dioxins and organic chlorine compounds such as PCBs discharged from the cement production facility. In addition, fuel for firing can be saved.

  Examples of the present invention will be specifically described below.

  In FIG. 1, reference numeral 10 denotes a cement firing facility to which a method for reducing organochlorine compounds in exhaust gas from a cement production facility according to Embodiment 1 of the present invention is applied. The cement firing facility 10 includes a raw material process unit for pulverizing a cement raw material and a firing process unit for firing the pulverized cement raw material.

  The raw material process section includes a raw material storage 11 that individually stores limestone, clay, silica, and iron raw materials as cement raw materials, a raw material dryer 12 that heats and drys the cement raw materials, a raw material mill 13 that pulverizes the cement raw materials, A first electric dust collector (dust collector) B1 that collects dust containing organochlorine compounds discharged from the raw material dryer 12 and the raw material mill 13, and a storage silo 14 that temporarily stores the cement raw material crushed by the raw material mill 13. I have.

  The cement raw material stored in the raw material storage 11 is put into the rotating drum of the raw material mill 13 through the raw material supply pipe 118. However, some cement raw materials such as clay are supplied to the raw material dryer 12 through the raw material supply facility 131. This part of the cement raw material is dried here and then fed into the raw material mill 13 through the dry raw material discharge facility 132. A large number of metal balls are housed in the rotating drum of the raw material mill 13. By continuously feeding the cement material while rotating the rotating drum, cement material powder pulverized to a particle size of approximately 90 μm can be obtained. The pulverized cement raw material is charged into the storage silo 14 via the pulverized raw material transport facility 121.

The raw material dryer 12 and the raw material mill 13 are respectively supplied with high-temperature exhaust gas (high-temperature gas) at 350 ° C. discharged from the upper part of the preheater 16 described later through an exhaust gas duct 21 having a bifurcated downstream portion. Therefore, the internal temperature of the raw material dryer 12 is maintained at about 300 ° C., and the internal temperature of the raw material mill 13 is maintained at about 100 ° C. or higher. A fan F <b> 1 is provided upstream of the exhaust gas duct 21.
The raw material dryer 12 and the raw material mill 13 are connected to each end portion of the upstream side portion of the flue 129 that opens the exhaust gas from the inside through the chimney 130 to the atmosphere. In the middle of the downstream side portion of the flue 129, the electric dust collector B1 having an internal temperature of 90 ° C. is provided. In addition, the flue 129 is provided with a fan F2 on the material mill 13 side on the upstream side which is a forked portion, and a fan F3 is provided between the electric dust collector B1 and the chimney 130.

A portion of the exhaust gas duct 21 between the bifurcated branch portion and the fan F1 is connected to a base portion of an exhaust gas branch pipe 150 having a tip portion connected to a coal inlet of a coal mill 50 described later. . A dust inlet 150 a is formed in the upstream portion of the exhaust gas branch pipe 150. The exhaust gas from the upper part of the preheater 16 is about 350 ° C., and the dust and the organochlorine compound contained in the exhaust gas are separated by the heat.
A dust delivery pipe in which a part of dust collection powder (powder) collected by the electrostatic precipitator B1 and containing an organic chlorine compound such as dioxins and PCB is bifurcated in the downstream is provided in the dust inlet 150a. 123 through. Specifically, a part of the dust collection dust is thrown into the dust inlet 150a through the branch pipe constituting one of the bifurcated portions in the downstream portion of the dust delivery pipe 123. Further, the remaining part of the dust collection dust is supplied to the raw material mill 13 through a branch pipe constituting the other of the bifurcated part in the downstream part of the dust delivery pipe 123.

In the exhaust gas branch pipe 150, the dust collected from the dust inlet 150 a comes into contact with the exhaust gas at 350 ° C. Thereby, the organic chlorine compound contained in the dust collection dust is vaporized and separated, or the organic chlorine compound is thermally decomposed.
In the exhaust gas branch pipe 150, a second electric dust collector B2 that collects dust collection dust not containing an organic chlorine compound from the exhaust gas is provided slightly downstream from the dust inlet 150a. The dust collection dust (the organic chlorine compound is removed) collected by the second electrostatic precipitator B2 is input to the raw material mill 13 through the organic removal dust pipe 151.

  Further, a fan F4 is provided in a portion of the exhaust gas branch pipe 150 slightly downstream from the second electric dust collector B2. Due to the negative pressure of the fan F4, part of the high-temperature exhaust gas flowing through the exhaust gas duct 21 flows into the exhaust gas branch pipe 150, and dust collection dust containing the organic chlorine compound collected by the first electric dust collector B1 is It flows into the pipe of the exhaust gas branch pipe 150 from the inlet 150a. Moreover, the dust removal gas containing the organic chlorine compound that has passed through the second electrostatic precipitator B2 flows into the coal mill 50 due to the negative pressure of the fan F4.

  The firing process section includes a preheater 16 having a multistage cyclone 15 that is gradually heated to a higher temperature as the cement raw material charged from the upper part is lowered, a calcining furnace having a combustion burner, and a preheater 16 at the bottom of the kiln. A dry rotary kiln 18 that has a combustion burner 17 to obtain cement clinker from a cement raw material, a clinker cooler 19 that cools the cement clinker discharged from the kiln of the rotary kiln 18, and a cement obtained. A clinker silo (not shown) that temporarily stores the clinker and a second dust collector (not shown) that collects dust discharged from the clinker silo are provided.

In the preheater 16, a pulverized raw material charged from the storage silo 14 via the raw material powder transporting facility 165 is easily passed through the upper and lower cyclones 15 from the upper side so as to be easily fired in the rotary kiln 18. C.).
A rotary kiln 18 that produces cement clinker at 100 t / h is employed. In the rotary kiln 18, the cement raw material is fired by the heat of the flame from the combustion burner 17 using coal fine powder pulverized by the coal mill 50 as fuel.
That is, in the firing process section, the cement raw material from the storage silo 14 is calcined while flowing down through the cyclones 15 and the calcining furnace of the preheater 16, and is then charged into the kiln bottom of the rotary kiln 18 from the lower stage of the preheater 16. Is done. Here, the cement clinker is fired by the burner heating by the combustion burner 17 while the cement raw material rotates in the circumferential direction as the kiln shell rotates. The obtained cement clinker is cooled by a clinker cooler 19.

The coal mill 50 has a rotating drum in which a large number of metal balls are stored. Coal and a dedusted gas containing an organic chlorine compound that has passed through the second electrostatic precipitator B2 are continuously charged into the rotating drum through a coal charging port. Thereby, the fine coal powder (adsorbed powder) by which the organic chlorine compound was adsorbed is obtained. The fine coal powder is continuously fed into the combustion burner 17 provided at the front of the kiln of the rotary kiln 18 through the fine coal delivery pipe 152. The amount of coal fine powder introduced from the fuel inlet is 500 to 900 g per 1 m ^{3 of} dust removal gas. Oil coke fine powder may be adopted instead of coal fine powder.

Next, the organic chlorine compound reduction method in the exhaust gas performed in the cement production facility 10 of Example 1 (inside the system) will be described.
As shown in FIG. 1, each cement raw material in the raw material storage 11 is put into the raw material mill 13 through the raw material supply pipe 118. However, some cement raw materials having a high water content such as clay are supplied to the raw material dryer 12 through the raw material supply facility 131. This part of the cement raw material is heated and dried in the high-temperature raw material dryer 12, and then is fed into the raw material mill 13 through the dry raw material discharge facility 132. High temperature exhaust gas is supplied to the raw material dryer 12 and the raw material mill 13 from above the preheater 16 through the exhaust gas duct 21. In the raw material mill 13, the cement raw material is pulverized to an average particle size of 10 to 30 μm by a large number of metal balls while all cement raw materials including the dry raw material supplied from the raw material dryer 12 are heated to about 75 ° C. The pulverized cement raw material is fed into the storage silo 14 through the pulverized raw material transport facility 121.

High temperature exhaust gas is supplied to the raw material dryer 12 and the raw material mill 13 from above the preheater 16 through the exhaust gas duct 21. Therefore, the internal temperature of the raw material dryer 12 is about 300 ° C., and the internal temperature of the raw material mill 13 is 100 ° C. or higher. The exhaust gas containing dust that has passed through the raw material dryer 12 and the raw material mill 13 is deprived of heat in the raw material dryer 12 and the raw material mill 13, and the inlet gas temperature of the electrostatic precipitator B1 is 90 ° C. Therefore, most of the organic chlorine compounds in the exhaust gas are adsorbed by dust.
As described above, the insides of the raw material dryer 12 and the raw material mill 13 are maintained at around 300 ° C. where dioxins are easily vaporized, for example. Therefore, when part of the cement raw material (for example, clay) is mixed with organic chlorine compounds such as dioxins and PCBs, and other wastes (such as municipal waste and incinerated ash) containing organic matter and chlorine, the raw material dryer 12 and The organic chlorine compound is vaporized in the raw material mill 13.

  Dust containing organochlorine compounds from the raw material dryer 12 and the raw material mill 13 is collected by an electric dust collector (dust collector) B 1, and part of the dust collected dust is one of the forked portions of the dust delivery pipe 123. It passes through the branch pipe and the dust inlet 150a, and flows into the exhaust gas branch pipe 150. Further, the remaining part of the dust collection dust is fed into the raw material mill 13 through a branch pipe constituting the other of the bifurcated part of the downstream part of the dust delivery pipe 123. Thereafter, the remaining part of the dust collection dust is temporarily stored in the storage silo 14 through the pulverized raw material transport facility 121 together with the cement raw material pulverized in the raw material mill 13.

Dust collection dust containing an organic chlorine compound that has flowed into the exhaust gas branch pipe 150 comes into contact with the exhaust gas from above the preheater 16 at about 300 ° C. that passes through the pipe. Thereby, the organic chlorine compound contained in the dust collection dust is vaporized and separated, or the organic chlorine compound is thermally decomposed. As a result, in the exhaust gas branch pipe 150, in the downstream portion from the dust inlet 150a, exhaust gas mixed with the organochlorine compound and the dust collection dust separated flows.
Thereafter, the exhaust gas in which these are mixed is sucked into the second electrostatic precipitator B2. Here, only dust collection dust not containing an organic chlorine compound is collected (filtered) from the exhaust gas.

  The dust collection dust from which the organic chlorine compound collected by the second electric dust collector B2 is removed is input to the raw material mill 13 through the organic removal dust pipe 151. On the other hand, the dedusted gas containing the organic chlorine compound that has passed through the second electrostatic precipitator B <b> 2 flows into the coal mill 50 through the exhaust gas branch pipe 150. As a mill, the same effect can be obtained by either a heel mill or a horizontal ball mill. As a result, the organochlorine compound is adsorbed on the coal being crushed. Thereby, the fine coal powder by which the organic chlorine compound (Dioxins, PCB, etc.) was adsorbed is produced.

  The obtained coal fine powder is continuously charged into the combustion burner 17 provided in the front part of the kiln of the rotary kiln 18 through the pulverized coal delivery pipe 152, and the cement clinker is fired by heating the burner. At this time, the organic chlorine compound contained in the coal fine powder is thermally decomposed. As a result, the amount of dioxins discharged from the cement manufacturing facility 10 and organic chlorine compounds such as PCBs can be reduced more than before. In addition, fuel for firing can be saved.

Here, the result of investigating the rate of reduction of organochlorine compounds in the exhaust gas released to the atmosphere using the cement production facility 10 of Example 1 (heating raw material use basic unit; at 50 kg / t.cli) is reported. To do.
That is, by using the cement production facility 10, PCB 95% by weight, acetaldehyde 99% by weight, methyl alcohol 99% by weight, chlorophenol 100% by weight, propanol 99% by weight and acetone from the dust gas Was 99% by weight or more, benzene was 99% by weight or more, and toluene was 99% by weight or more. These are typical harmful substances that must be removed from the gas by 99% by weight or more of dedusting.

It is a schematic block diagram of the cement baking equipment to which the organochlorine compound reduction method in the waste gas of the cement manufacturing equipment concerning Example 1 of this invention was applied.

Explanation of symbols

10 Cement production equipment,
13 Raw material mill,
16 Preheater,
18 Rotary kiln,
B1 first electric dust collector (dust collector),
B2 Second electric dust collector (dust collector).

Claims (5)

In a cement production facility for firing cement clinker from a cement raw material, a powder containing an organic chlorine compound is contacted with a high-temperature gas at 100 ° C. or higher in the cement production facility, and the organic chlorine compound is separated from the powder or An organic matter removal step for decomposing,
A powder removal step of collecting and removing the powder from which the organochlorine compound has been separated or decomposed from the high temperature gas in contact with the powder;
An organic substance adsorption step in which the powder is removed and the high temperature gas containing the organochlorine compound is brought into contact with the adsorbed powder, and the adsorbed powder adsorbs the organochlorine compound;
A decomposition step of decomposing the organic chlorine compound adsorbed on the adsorbed powder by using the adsorbed powder adsorbed with the organic chlorine compound as a fuel for firing the cement clinker. A method for reducing organochlorine compounds in exhaust gas from cement production facilities.   The method for reducing organochlorine compounds in exhaust gas of a cement manufacturing facility according to claim 1, wherein the powder is dust collection dust collected by a dust collector in the cement manufacturing facility.   The said high temperature gas is the waste gas discharged | emitted from the upper part of a preheater at the time of baking of the said cement clinker, The waste gas of the cement manufacturing equipment of any one of Claim 2 or Claim 3 characterized by the above-mentioned. Organochlorine compound reduction method.   The adsorbed powder is any one of coal fine powder and oil coke fine powder which are fuels for burning the cement clinker, and any one of claims 1 to 3. Item 4. A method for reducing organochlorine compounds in exhaust gas from a cement production facility according to item.   The cement according to any one of claims 1 to 4, wherein the powder removed in the powder removing step is put into a raw material mill for pulverizing the cement raw material for firing. A method for reducing organochlorine compounds in exhaust gas from manufacturing facilities.

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