JP2002265965A - Process for producing pixel, solid fuel thereof and apparatus for fuel production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for producing a solid fuel having a small chlorine content from a raw material such as chlorine-based resin waste and to provide a solid fuel thereof and an apparatus for producing the fuel. SOLUTION: The process and apparatus for the production of a fuel comprises the carbonization combustion of a chlorine-containing combustibles under an oxidizing atmosphere to thereby vaporize and remove the chlorine component and the production of a solid fuel from the carbonized combustion residue, preferably with neutralizing a waste gas by charging a neutralizing treatment into the waste gas evolving at the time of carbonization combustion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for converting a combustible material containing chlorine into a solid fuel for effective use, and more particularly to a method for producing a solid fuel from a chlorine-based resin waste material such as polyvinyl chloride as a raw material. , And its solid fuels.

[0002]

2. Description of the Related Art Conventionally, chlorine-based resin waste materials have been disposed of in landfills or incinerated. However, incineration causes a problem that hydrogen chloride and dioxin are generated, resulting in air pollution. Therefore, in recent years, there has been a demand for a treatment method that does not cause such a problem for chlorine-containing waste such as polyvinyl chloride.

On the other hand, attempts have been made to use waste such as polyvinyl chloride products as fuel. Also in this case, it is necessary to carry out desalination treatment so that hydrogen chloride and dioxin are not generated during combustion, and a method of treating exhaust gas has been studied. As this prior art, for example, an externally heated screw type dechlorination apparatus is disclosed (Urban Cleaning Vol. 52, No. 232 [1999.10], p. 29-33). However,
Since the desalted material at low temperature becomes a lump, a pulverization cost is required. Further, when heating in a reducing atmosphere, it is necessary to shut off the leak of the atmosphere, which imposes a heavy burden on the apparatus configuration. Further, a method of absorbing the generated hydrogen chloride in water and neutralizing it with caustic soda has been practiced, but this wastewater treatment is also expensive. In addition, a method of directly crushing a polyvinyl chloride pipe or the like by finely pulverizing the pipe or the like is also being studied, but the cost of the fine pulverization increases, and practical use is difficult at present.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems. The present invention solves the above-mentioned problem by carbonizing and burning a chlorine-containing combustible such as polyvinyl chloride in an oxidizing atmosphere to volatilize and remove a chlorine component. A method for producing a solid fuel that does not substantially generate dioxin or the like when used as a fuel, has a sufficient calorific value, and is capable of obtaining a solid fuel that can be easily pulverized. A solid fuel and a fuel conversion device are provided.

[0005]

According to the present invention, there is provided a fuel conversion method having the following constitution. (1) A fuel conversion method in which a combustible material containing chlorine is carbonized and burned in an oxidizing atmosphere to volatilize and remove a chlorine component, and the carbonized combustion residue is used as a solid fuel. (2) The above (1) in which the chlorine-containing combustible material is chlorine-based resin waste material
The fuel conversion method described in 1. (3) The above-mentioned flammable material containing chlorine is 50 mm or less.
The fuel conversion method according to any one of (1) and (2). (4) The above wherein the carbonization combustion temperature is 400 to 1000 ° C.
The fuel conversion method according to any one of (1) to (3). (5) Chlorine-containing combustibles are carbonized and burned in an oxidizing atmosphere to volatilize and remove chlorine components, and the carbonized combustion residues are recovered. On the other hand, the exhaust gas is guided to a secondary combustion chamber to completely burn unburned components in the exhaust gas. The fuel conversion method according to any one of the above (1) to (4). (6) The neutralizing agent consisting of glass powder or alkali powder is added to the exhaust gas generated when carbonizing and combusting the chlorine-containing combustibles, and the salt is reacted with the chlorine component contained in the exhaust gas to desalinate (1). The fuel conversion method according to any one of (1) to (5). (7) When the exhaust gas generated when carbonizing and combusting the chlorine-containing combustibles is introduced into the secondary combustion chamber for complete combustion or after complete combustion, a neutralizing agent composed of glass powder or alkali powder is further charged. The method according to the above (6), wherein the fuel is reacted with a chlorine component contained in the exhaust gas to desalinate. (8) The method of (6) or (7) above, wherein one or more of waste glass, calcium carbonate, quicklime, and slaked lime is used as a neutralizing agent. (9) The fuel conversion method as described in any one of (6) to (8) above, wherein the neutralizing agent composed of glass powder or alkali powder introduced into the exhaust gas is recovered and reused as a part of the cement raw material. (10) The fuel conversion method according to any one of the above (1) to (9), wherein the solid fuel obtained by the carbonization combustion is pulverized into powder.

[0006] The present invention also relates to a solid fuel and a fuel conversion device having the following constitution. (11) A solid fuel converted into a fuel by any one of the above (1) to (10). (12) The solid fuel according to the above (11), wherein the amount of chlorine is 2% or less. (13) The above (11) in which the calorific value is 3000 kcal / kg or more.
Or the solid fuel according to any of (12). (14) a primary combustion furnace for carbonizing and burning chlorine-containing combustibles;
A fuel conversion system comprising: a secondary combustion chamber for completely combusting exhaust gas from a primary combustion furnace; and a means for supplying and recovering a neutralizing agent provided in the secondary combustion chamber. (15) The fuel conversion device according to (14), wherein the primary combustion furnace is a rotary kiln.

According to the fuel conversion method and apparatus of the present invention,
As described above, since chlorine-containing combustibles are dechlorinated by carbonization and combustion in an oxidizing atmosphere, dioxins and the like are not substantially generated even when they are used as a solid fuel.
In addition, it is possible to obtain a solid fuel which has a sufficient calorific value and is easily pulverized. Further, the chlorine component gasified by the carbonization combustion is neutralized by glass powder or slaked lime, and is fixed as an alkali compound or a calcium compound and separated from the exhaust gas. There is no fear.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments. (Fueling method) The fueling method of the present invention uses a combustible containing chlorine as a starting material, and carbonizes and combusts this in an oxidizing atmosphere to volatilize and remove chlorine components. How to Chlorine-based resin materials such as polyvinyl chloride, polyvinylidene chloride, chlorinated polyethylene, and chlorinated polyolefin can be used as the chlorine-containing combustible materials. In particular, waste materials of polyvinyl chloride products such as polyvinyl chloride pipes and sheets are used. In addition, chlorine-containing combustible waste such as polyvinyl chloride construction waste, household waste and agricultural waste can be used. This chlorine-containing combustible is 50 mm or less, and preferably 3 to
The one crushed to about 20 mm is good. As the crushing means, any crusher such as a bimer or a CS cutter can be used.

The chlorine-containing combustibles are carbonized and burned in an oxidizing atmosphere to volatilize and remove chlorine components. The carbonization combustion means that a chlorine component contained in the combustible material is volatilized and removed as a chlorine gas or a hydrogen chloride gas, and at the same time, the volatile combustibles that are volatilized are burned to form a carbonized combustion residue. By burning in a predetermined temperature range in an oxidizing atmosphere, a black porous carbonized residue in which a chlorine component and volatile combustibles have volatilized is obtained.
It should be noted that carbonized combustion (primary combustion) is terminated before complete combustion because the carbonized residue is further burned to ash when completely burned. In addition, when thermally decomposed in a reducing atmosphere, the carbon component is tarred, and a desired solid fuel cannot be obtained.

[0010] The combustion temperature of carbonization combustion (primary combustion) is preferably 400 ° C or higher in order to remove chlorine components contained in combustibles. Further, in order to suppress the generation of unburned gas and the generation of dioxin, the combustion temperature is set to 700 ° C to 1000 ° C.
Is preferred. The burning time may be about 1 to 10 minutes per ton, depending on the amount charged in the furnace.

A rotary kiln is preferable as a combustion furnace for carbonizing and burning chlorine-containing combustibles. In particular, an internal heat type rotary kiln is preferable because of its good thermal efficiency. It is preferable that combustion be promoted by using the inclination of the rotary kiln and that the residue be easily removed. That is, a crushed material of chlorine-containing combustible material is blown from the lower end of the inclined rotary kiln, and while the crushed material makes a U-turn in the furnace and returns to the end of the blowing side, carbonization combustion proceeds, and the combustion residue is removed. Remove from this end. In addition, the residence time is adjusted according to the number of rotations of the kiln,
The degree of carbonization combustion can be controlled together with the furnace temperature. In addition, if a rotary kiln having a length that can be controlled during a predetermined residence time is used, a pulverized chlorine-containing combustible may be fed from the upper end by a feeder or the like.

The carbonized combustion residue generated by the primary combustion is taken out of the furnace and used as a solid fuel. When this solid fuel is used as a fuel for an industrial furnace, for example, a fuel for burning cement, it is preferable to pulverize the solid fuel to an average particle diameter of 200 μm or less. In addition, since the combustion residue generated by this primary combustion is a shell in which hydrogen chloride and the like have volatilized and has a hardness that can be crushed by hand, use a special crusher that crushes the raw material such as polyvinyl chloride. No need,
It can be easily pulverized to a desired particle size. The pulverizing means may be any means such as a ball mill, a vertical mill, or a combination of a roll press and a separator.

The solid fuel thus obtained has a chlorine content of about 2 wt% or less because the chlorine component has been removed by carbonization and combustion, and since the solid fuel contains a large amount of the carbon component, the solid fuel has a chlorine content of 3000 kcal / kg or more. It can have a calorific value. Therefore, even when burned, generation of chlorine-based gas is extremely small, and problems such as dioxin do not substantially occur.

On the other hand, it is desirable that the volatile combustible components generated by carbonizing and combusting the chlorine-containing combustibles in an oxidizing atmosphere be completely burned in the primary combustion furnace, but not completely burned in the primary combustion furnace. Alternatively, the exhaust gas containing the unburned gas may be guided to the secondary combustion chamber to be completely burned. Unburned gas contained in the exhaust gas burns almost completely by heating it to 700 ° C. or higher in the secondary combustion chamber. Moreover, the effect of thermally decomposing dioxin generated when the combustion temperature of the primary combustion furnace is 400 to 700 ° C. in the secondary combustion chamber is also obtained.

Further, a neutralizing agent composed of glass powder or alkali powder is added to the exhaust gas generated by the carbonization combustion, and is reacted with a chlorine component contained in the exhaust gas to desalt and neutralize the exhaust gas. preferable. Specifically, for example, a charging means and a collecting means for the neutralizing agent are provided in the secondary combustion chamber, and the neutralizing agent is injected into the exhaust gas after complete combustion. As the neutralizing agent, glass powder, limestone powder (calcium carbonate powder), quicklime, slaked lime and the like can be used. The glass powder only needs to contain an alkali metal component, and waste glass can be used, and colored glass may be used. This neutralizing agent is 20 μm to increase the reactivity.
What is finely ground below is preferable. Further, in order to recover the waste after use and reuse it as a part of the cement raw material, a mixed powder of limestone powder and waste glass is preferable.

When glass powder is used as the neutralizing agent, the temperature is 250 to 700 ° C., preferably 350 to 600 ° C.
It is preferred to contact the exhaust gas at a temperature of ° C. Therefore, it is preferable to react the secondary combustion high temperature exhaust gas by blowing a fine neutralizing agent. If the temperature is lower than 250 ° C., the reaction is insufficient. If the temperature is higher than 700 ° C., the surface of the glass powder is melted and the reactivity becomes low.

By blowing the powder of the neutralizing agent into the high-temperature exhaust gas, the chlorine component contained in the exhaust gas and the alkali metal component contained in the glass powder, or the calcium component of limestone, quicklime and slaked lime react to react with the alkali metal. Chloride and calcium chloride are formed. If the generated alkali metal chloride has a volatilization temperature higher than the exhaust gas temperature, it is solidified and becomes fine particles and floats in the exhaust gas, and if the volatilization temperature is lower than the exhaust gas temperature, it is gasified and contained in the exhaust gas. By separating the generated chloride from the exhaust gas together with the glass powder and the like, the chlorine component can be removed from the exhaust gas and desalted.

After the desalting treatment, if necessary, the exhaust gas is cooled to a temperature lower than the melting point of the generated alkali metal chloride, and the generated chloride is solidified. Collect and separate from flue gas. Separation of the generated chloride from the exhaust gas prevents corrosion and adhesion of a water pipe such as a boiler to be provided later, thereby facilitating reuse of heat of the high-temperature exhaust gas.

Neutralizing agents such as recovered glass powder, limestone powder, decarboxylated lime powder, slaked lime powder that has reacted with moisture in the exhaust gas, may be washed with water, if necessary, to remove chlorides. It can be used as a part of a cement raw material or a part of another manufacturing raw material.

As described above, according to the fuel conversion method of the present invention, material recycling as a solid fuel can be easily carried out by carbonizing and burning chlorine-containing combustibles such as polyvinyl chloride waste. The heat generated during the carbonization combustion can also be thermally recycled. Furthermore, since the chlorine component contained in the exhaust gas is removed by neutralizing the exhaust gas of the primary combustion furnace in the neutralization tower or the secondary combustion chamber, no polluting sources such as dioxin are released into the atmosphere. Pollution is also prevented.

[Fueling Apparatus] An apparatus system suitable for the fueling method of the present invention is schematically illustrated in the process diagram of FIG. The illustrated fuel conversion apparatus includes a primary combustion furnace 14 for carbonizing and burning chlorine-containing combustibles such as polyvinyl chloride waste material, and a primary combustion furnace 1.
4 includes a secondary combustion chamber 22 for completely burning the exhaust gas, and a neutralizing agent supply means 20 and a recovery means 25 provided in the secondary combustion chamber 22. As the primary combustion furnace 14, a rotary kiln used in a cement manufacturing process can be used. The rotary kiln 14 is provided with a nozzle 12 for blowing a pulverized material such as polyvinyl chloride waste material into the furnace, and the nozzle 12 is provided with means 1 to 8 for crushing and supplying the polyvinyl chloride waste material and the like. I have.

The secondary combustion chamber 22 is connected to the exhaust gas outlet of the rotary kiln 14 and has a combustion burner 21 for completely burning unburned gas. Above the burner 21, a supply means 20 for the neutralizing agent is provided. This supply means 20 includes a supply device 17 for waste glass or the like,
18 and a crusher 19 are connected. On the other hand, a cooling chamber 24 is formed above the secondary combustion chamber 22, a cyclone separator 25 is mounted, and a ceramics filter 28 is provided at the outlet.

An example of a fuel conversion process using the above-described apparatus system will be described below. First, waste polyvinyl chloride pipe is sent from the feeder 1 to the crusher 2, crushed to about 20 to 30 mm, and then introduced into the quantitative feeder 3. The massive crushed polyvinyl chloride discharged from the metering device 3 is crushed by the crusher 4 to a size of about 3 to 20 mm. This is separated to a particle size of 6 mm or less by a vibrating sieve 5, and the crushed material having a particle size of 6 mm or more is returned to the middle crusher 4 again to be crushed again. The air is conveyed to the nozzle 12 by the blower 7 and blown into the rotary kiln 14 from the nozzle 12. The rotary kiln 14 is inclined about 5 degrees so that the nozzle side becomes lower.

On the other hand, heavy oil is supplied to the burner 13 through the heavy oil tank 9 and the heavy oil pump 10, and the fuel is supplementarily burned to keep the inside of the furnace of the rotary kiln at about 800 ° C. The pulverized polyvinyl chloride supplied into the furnace is carbonized and burned in this oxidizing atmosphere (air ratio of 1 or more). The furnace temperature is adjusted by increasing or decreasing the amount of heavy oil. The pulverized polyvinyl chloride material introduced into the furnace is carbonized and burns to volatilize hydrogen chloride, and the combustion residue moves downward along the slope with the rotation of the kiln, and is dropped into the collection box 11 to be collected. I do. The recovered unburned carbonized residue is approximately 1 to 5 mm particles. In an example analyzed, the calorific value is 3000 to 5000 kcal / kg and the residual chlorine amount is 2% or less. The calorific value, chlorine content, and particle size of the unburned residue can be controlled by the rotation speed, burning time, and burning temperature of the rotary kiln.

On the other hand, hydrogen chloride and unburned gas generated by carbonization combustion of the pulverized polyvinyl chloride are discharged from the secondary combustion chamber 22.
It is led to. Heavy oil is supplied to the burner 21 of the secondary combustion chamber 22 via a heavy oil tank 15 and a heavy oil pump 16, and is heated to about 800 ° C. as an ignition source to completely remove unburned gas contained in exhaust gas. Burn. The auxiliary combustion source of the secondary combustion chamber 22 is not limited to heavy oil, but may be a combustible component such as waste plastic. After the unburned gas and the organic chlorine compounds such as dioxin contained in the exhaust gas are completely burned, the mixed powder of limestone and waste glass is put into the room by the quantitative feeder 20 provided above the burner 21. Limestone and waste glass are supplied to pulverizers 19 by supply devices 17 and 18, and those finely pulverized to 20 μm or less are introduced according to the amount of hydrogen chloride in the exhaust gas to neutralize the exhaust gas.

The neutralized exhaust gas is led to a cooling chamber 24 formed above the secondary combustion chamber 22, cooled to a temperature lower than the melting point of chloride by cold air taken in from an air inlet 23, and then led to a cyclone 25. Here, coarse solids having a low salt content, such as glass powder and limestone powder, contained in the exhaust gas are collected by the cyclone separator 25 and guided to the collection box 27 via the dump bar 26.

Exhaust gas discharged from the cyclone 25 is guided to a high-temperature ceramics filter 28. Here, fine solids containing a large amount of salt such as sodium chloride and potassium chloride generated by the neutralization treatment are recovered. The fine powder is sent to the collection box 35 by the carrier 29. On the other hand, the exhaust gas discharged from the filter 28 is a high-temperature exhaust gas of 250 ° C. or higher, which contains less hydrogen chloride and salt. This is boiler 3
Lead to 1 to recover heat. The inlet temperature of the boiler 31 can be controlled by the damper 30. Exhaust gas from the boiler 31 is discharged through a chimney 33 through a blower 32.

[0028]

EXAMPLE A solid fuel was produced from a waste polyvinyl chloride material by the fueling system shown in FIG. The results are shown in Table 1 together with the production conditions. In any of Examples 1 to 3, the residual chlorine amount was 2% or less and the calorific value was 300%.
Solid fuel of 0 kcal / kg or more can be obtained. In each case, the chlorine concentration in the exhaust gas finally discharged is 1
It was 0 ppm or less.

[0029]

[Table 1]

[0030]

As described above, according to the present invention, it is possible to easily produce a solid fuel obtained by material-recycling chlorine-based resin waste such as polyvinyl chloride, thereby suppressing the generation of pollution and the waste. Can be effectively used.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a processing system according to the present invention.

[Explanation of symbols]

12-nozzle, 13-burner, 14-rotary kiln (primary combustion furnace) 20-neutralizing agent supply means, 22-secondary combustion chamber, 24-cooling chamber, 25-cyclone, 28-ceramics filter, 31-boiler

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F23G 5/14 ZAB B01D 53/34 134A 4H012 F23J 15/02 F23J 15/00 C 4H015 (72) Inventor Yoshikawa Chihisa 2-4-2, Daisaku, Sakura-shi, Chiba Pref., Central Research Institute of Cement Co., Ltd. (72) Inventor Hisanori Aoyama 2-4-2, Osaku, Sakura-shi, Chiba Pref. Nori 6276 Onoda, Onoda City, Yamaguchi Prefecture Hiroshi Taihei Cement Co., Ltd.Environmental Technology Development Center F term (reference) 3K061 AA07 AB02 AC13 BA01 BA07 BA08 CA02 FA05 FA10 FA21 FA25 GA07 GA08 GA09 GA10 KA02 3K070 DA12 DA32 DA35 DA38 DA49 DA83 3K0A BA01 BA21 CA02 CA21 CA25 CA27 4D002 AA18 BA03 CA01 DA05 DA11 DA12 DA16 DA66 EA05 EA13 HA09 4F301 AA16 CA09 CA25 CA26 CA52 CA65 CA72 4H012 HB07 HB09 4H015 AA02 AA17 AA25 AA27 AB01 AB07 BA05 BA12 BB03 CA03 CB01

Claims (15)

[Claims] 1. A fuel conversion method in which a chlorine-containing combustible is carbonized and burned in an oxidizing atmosphere to volatilize and remove a chlorine component, and a carbonized combustion residue is used as a solid fuel. 2. The method according to claim 1, wherein the chlorine-containing combustible material is a chlorine-based resin waste material. 3. The method according to claim 1, wherein the chlorine-containing combustible material is a crushed material having a size of 50 mm or less. 4. The method according to claim 1, wherein the carbonization combustion temperature is 400 to 1000 ° C. 5. A chlorine-containing combustible material is carbonized and burned in an oxidizing atmosphere to volatilize and remove a chlorine component, and a carbonized combustion residue is recovered. On the other hand, an exhaust gas is guided to a secondary combustion chamber to remove unburned components in the exhaust gas. The fuel conversion method according to claim 1, wherein the fuel is completely burned. 6. An exhaust gas generated when carbonizing and combusting a chlorine-containing combustible is charged with a neutralizing agent composed of a glass powder or an alkali powder, and reacted with a chlorine component contained in the exhaust gas for desalination. 6. The fuel conversion method according to any one of 1 to 5. 7. A neutralizing agent comprising glass powder or alkali powder when exhaust gas generated during the carbonization combustion of the chlorine-containing combustible is introduced into the secondary combustion chamber for complete combustion or after complete combustion. 7. The fuel conversion method according to claim 6, wherein the fuel is introduced and reacted with a chlorine component contained in the exhaust gas for desalination. 8. The method according to claim 6, wherein one or more of waste glass, calcium carbonate, quicklime and slaked lime are used as the neutralizing agent. 9. The fuel conversion method according to claim 6, wherein a neutralizing agent comprising glass powder or alkali powder introduced into the exhaust gas is recovered and reused as a part of a cement raw material. 10. The method according to claim 1, wherein the solid fuel obtained by the carbonization combustion is pulverized into powder. 11. A solid fuel converted into a fuel by the method according to claim 1. 12. The solid fuel according to claim 11, wherein the amount of chlorine is 2% or less. 13. The solid fuel according to claim 11, which has a calorific value of 3000 kcal / kg or more. 14. A primary combustion furnace for carbonizing and burning a chlorine-containing combustible, a secondary combustion chamber for completely combusting exhaust gas from the primary combustion furnace, and a means for supplying and recovering a neutralizing agent provided in the secondary combustion chamber. A fuel conversion device comprising: 15. The fuel conversion device according to claim 14, wherein the primary combustion furnace is a rotary kiln.