JP3351294B2 - Method and apparatus for treating chlorine-containing synthetic resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for treating a chlorine-containing synthetic resin, removing chlorine, and decomposing the resin into a pyrolysis residue mainly composed of carbon or hydrocarbon.

[0002]

2. Description of the Related Art In recent years, synthetic resins such as plastics have been increasing as industrial wastes and general wastes, and their disposal has become a serious social and environmental problem. Among them, the chlorine-containing synthetic resin generates hydrogen chloride gas at the time of combustion and causes facility problems such as damaging the wall of the incinerator.

It is also known that burning a chlorine-containing synthetic resin may produce harmful substances such as dioxins. Therefore, the current disposal method is that the waste is disposed of in landfills. However, dumping of plastics and the like causes land subsidence and is not preferable in terms of environmental measures.In addition, shortage of land for landfills has recently become a social problem. The development of methods is eagerly awaited.

The above-mentioned discarded synthetic resins contain on average about 15% of a chlorine-containing synthetic resin such as a vinyl chloride resin. A large amount of harmful gas (HCl) is generated by thermal decomposition and combustion of the synthetic resin contained, damaging the blast furnace lining and causing significant environmental pollution. Therefore, in order to prevent the generation of such harmful gases, it is necessary to remove chlorine from the chlorine-containing synthetic resin in advance.

Conventionally, as a method for treating a chlorine-containing synthetic resin, there has been known a method using a rotary kiln as disclosed in JP-A-50-127981. This method is characterized in that when supplying a chlorine-containing synthetic resin into the kiln in an externally heated rotary kiln, waste oil or the like is supplied into the kiln in advance in order to prevent the resin from adhering to the inner wall of the kiln.

Japanese Patent Application Laid-Open No. 7-316339 discloses a method for thermally decomposing a chlorine-containing synthetic resin. In this method, sand as a heat medium is supplied, and a heating gas is supplied as a heat source. The chlorine-containing synthetic resin is mixed with the sand by the rotation of the kiln for about 250 to 3 times.
The resin is heated to about 50 ° C., and by this heating, the chlorine content in the resin is separated as hydrogen chloride gas.

[0007] The hydrogen chloride gas is discharged out of the kiln together with the heating gas, and the residue of the chlorine-containing synthetic resin that has been dechlorinated is thermally decomposed residue (residual solid matter of the resin).
Is discharged out of the kiln together with the sand as a heat medium, which makes subsequent processing difficult.

In Japanese Patent Application Laid-Open No. 8-155419, in order to prevent agglomeration and clumping of wastes and pyrolysis residues in a rotary kiln, a hard rolling element is provided in the rotary kiln, and There is disclosed a technology in which a weir or baffle plate for preventing the rolling element from flowing down is provided.

[0009]

However, the conventional chlorine removal method using such a rotary kiln has the following problems. In Japanese Patent Laid-Open No. 50-127981, the waste oil or the like supplied into the kiln must be stable at the dechlorination temperature, but the carbide adheres to the kiln inner wall by coking of the supplied waste oil.
This reduces the heat transfer area and reduces the heat efficiency from the heated gas. Oils stable at the above-mentioned processing temperatures are expensive and are not economical as a method for treating waste.

In JP-A-7-316339, sand is mainly used as a heat medium to be charged into the kiln together with the resin material. The sand can be prevented from adhering to the inner wall of the kiln. The segregation in the kiln is likely to occur due to the large difference in specific gravity and specific gravity, so that it does not function effectively as a heating medium, and the processing efficiency is low.

On the assumption that the dechlorinated resin material residue is used as a raw material to be blown into or charged into a blast furnace or the like (mainly a reducing material or fuel for an iron source), sand is used as a heat medium. Since it is used, it is necessary to separate sand from the residue of the resin material after the dechlorination treatment is completed, and there is a problem that the equipment cost for this treatment is increased.

The process of dechlorinating a chlorine-containing synthetic resin starts with the softening of the chlorine-containing synthetic resin, and upon further heating, starts dechlorination. In Japanese Patent Application Laid-Open No. 8-155419, a hard rolling element is inserted to prevent agglomeration and agglomeration of waste or pyrolysis residue, and a weir or baffle plate is provided. The softened melt of the chlorine-containing synthetic resin may adhere to the plate and grow, opening the inner tube of the rotary kiln.

[0013] Wastes of chlorine-containing synthetic resins have a wide variety of properties and shapes depending on applications. It can be broadly classified into thin film waste used for packaging materials and solid waste used for housings of home electric appliances and the like. It is difficult to treat these chlorine-containing synthetic resins having various shapes and properties as they are in a single-stage rotary kiln for the following reasons.

The chlorine-containing synthetic resin in the form of a film has a bulk density of 0.1 kg / m ³ or less and a solid one of 0.3 kg / m ^3.
And it is difficult to feed them simultaneously and quantitatively into the rotary kiln. In addition, even if a plurality of fixed-quantity supply devices depending on the shape of the chlorine-containing synthetic resin are installed, the characteristics (repose angle, fluidization characteristics, etc.) of various powders vary depending on the shape, so that the operation of the rotary kiln is stably maintained. It is difficult.

Accordingly, an object of the present invention is to solve such problems of the prior art, and to remove chlorine in advance and recover as hydrogen chloride in the treatment of a chlorine-containing synthetic resin, to recover a pyrolysis residue and heat the same. It is an object of the present invention to provide a form that can be reused as a carbon material or a raw material that can be charged into a furnace or a blast furnace.

[0016]

The features of the present invention for solving such a problem are as follows. The method for treating a chlorine-containing synthetic resin according to the present invention comprises the steps of: heating the chlorine-containing synthetic resin together with a solid heat medium in an inert gas atmosphere at 200 ° C
This is a method for treating a chlorine-containing synthetic resin which is thermally decomposed by heating to a temperature of 500 ° C. or lower to pyrolyze chlorine contained in the chlorine-containing synthetic resin into hydrogen chloride to obtain a pyrolysis residue. The inert gas atmosphere refers to a case where a gas other than the gas generated by thermal decomposition is a nitrogen gas, an argon gas, or a non-oxidizing gas.

When the chlorine-containing synthetic resin is a film-like chlorine-containing synthetic resin, the film-like chlorine-containing synthetic resin is first crushed and further reduced in volume.
It is desirable to perform the thermal decomposition.

When the chlorine-containing synthetic resin is a solid chlorine-containing resin, it is preferable that the solid chlorine-containing synthetic resin is first crushed and thermally decomposed. Furthermore,
Hydrogen chloride generated in the thermal decomposition can be recovered as hydrochloric acid by adding water.

As the solid heat medium, any one of coke, coal, iron ore, sintered ore, granular iron and iron scrap, or a mixture thereof can be used. Further, the chlorine-containing synthetic resin can be treated even if it is a synthetic resin containing 20 wt% or more of the chlorine-containing synthetic resin.

The apparatus for treating a chlorine-containing synthetic resin according to the present invention comprises the following members. (A) means for crushing a film-like chlorine-containing synthetic resin or solid chlorine-containing synthetic resin, (b) means for reducing the volume of chlorine-containing resin crushed by the equipment, and (c) means for reducing the volume Means for thermally decomposing the chlorine contained in the chlorine-containing synthetic resin into hydrogen chloride and a pyrolysis residue, together with the solid heat medium, and (d) means for recovering the hydrogen chloride.

The thermal decomposition means has the following members. (A) An inner cylinder into which a chlorine-containing synthetic resin is charged from one inlet and a pyrolysis residue generated by thermal decomposition is discharged from another outlet, and a passage through which a heating gas for heating the inner cylinder from the outside flows. And (b) disposed at the inlet of the pyrolysis furnace.
A supply device for supplying a chlorine-containing synthetic resin and a solid heat medium to the pyrolysis furnace, respectively, and (c) hydrogen chloride generated by the pyrolysis, which is disposed to be connected to the outlet of the pyrolysis furnace. A conduit connected to the collecting means, and a device for discharging the pyrolysis residue generated in the pyrolysis.

Here, the means for recovering hydrogen chloride is as follows:
It is desirable to use a wet recovery device such as a venturi scrubber.

[0023]

BRIEF DESCRIPTION OF THE DRAWINGS The method and the device according to the invention are illustrated in the following figures. FIG. 1 is a flowchart showing an example of the method and equipment for treating a chlorine-containing synthetic resin of the present invention, and the present invention will be described based on this flowchart.

In FIG. 1, reference numeral 1 denotes a means for crushing a film-like synthetic resin F, 2 denotes a crushing means for crushing a solid chlorine-containing synthetic resin S, and 3 denotes a crushed film-like synthetic resin. A means for reducing the volume of the chlorine-containing synthetic resin; a pyrolysis means for thermally decomposing the chlorine-containing synthetic resin;
Is a means for crushing the pyrolysis residue provided as necessary according to the form of use, 7 is a means for sieving the pyrolysis residue as necessary, 5 is hydrogen chloride generated from the pyrolysis means 4 Is preferably recovered as hydrochloric acid.

The film-like synthetic resin is crushed by one crushing means. The particle size after crushing is a size that can be supplied to the volume reducing means (3). The container, plate-like, and rod-like solid chlorine-containing synthetic resins are crushed by the crushing means (2). As the crushing means 1 and 2, for example, a single roll crusher or a double roll crusher can be used.

The film-shaped chlorine-containing synthetic resin F crushed by the crushing means 1 is reduced in volume to the same bulk density as the solid chlorine-containing synthetic resin by the volume reducing means 3. This bulk density is a bulk density that does not hinder the operation of the thermal decomposition means 4 and is preferably reduced to the same bulk density as the solid heat medium used in the thermal decomposition means. For example, when coke is used as the solid heat medium, the bulk density is 400 k.
g / m ³ .

As the solid heat medium, any one of coke, coal, iron ore, sintered ore, granular iron and iron scrap, or a mixture thereof can be used. These solid heating media can be reused without being separated from the pyrolysis residue. That is, when the solid heat medium is coke or coal, it can be reused, for example, as a fuel or a reducing agent for a heating furnace or a blast furnace, and when the solid heat medium is iron ore, sintered ore, or granular iron, it can be reused as a blast furnace raw material.

The above-mentioned chlorine-containing synthetic resin can be treated even if it is a synthetic resin containing 20 wt% or more of the chlorine-containing synthetic resin. This is because the thermal decomposition can be performed even when the chlorine-containing synthetic resin is mixed with a chlorine-free resin such as polyethylene.

The volume reducing means is to convert a film-based chlorine-containing synthetic resin having a bulk density of 0.1 kg / m ³ or less to a bulk density of 0.4 kg / m 3.
^{This is a} volume reducing means for increasing the volume up to about ³ , for example, a mechanical press or an extruder can be used. Further, a volume reducing means for generating frictional heat or supplying hot air or the like from outside may be used. However, the temperature is preferably lower than the temperature at which the chlorine-containing synthetic resin generates hydrogen chloride. Specifically, the temperature is desirably 250 ° C. or lower.

Since the synthetic resin from which chlorine has been removed by the pyrolysis means 4 is a pyrolysis residue having a diameter of about 100 mm or less, it is desirably crushed by the crushing means 6 to have a shape and size suitable for reuse. It is desirable to process. If necessary, it is sieved by the sieving means 7 and is processed so as to be suitable for reuse.

FIG. 2 shows the details of the thermal decomposition means 4. A metal inner cylinder 11 into which chlorine-containing synthetic resin is charged from one inlet and pyrolysis residues generated by pyrolysis are discharged from the other outlet.
And a metal outer cylinder 10 arranged so as to form a heating gas passage 13 through which a heating gas for heating the inner cylinder from the outside is formed.

At the inlet of the pyrolysis furnace, supply pipes 14 and 15 for supplying a chlorine-containing synthetic resin and a solid heat medium to the pyrolysis furnace are provided. Further, a conduit connected to the outlet of the pyrolysis furnace and connected to a means for collecting the hydrogen chloride generated by the pyrolysis is provided, and a device for discharging the pyrolysis residue generated by the pyrolysis is provided. .

There may be a plurality of inner cylinders 11 in terms of heat efficiency and throughput, and the positional relationship between the solid heat medium supply pipe 15 and the chlorine-containing synthetic resin supply pipe 14 is determined by the solid heat medium supply pipe 1.
5 is preferably disposed below the chlorine-containing synthetic resin supply pipe, and the solid heat medium supply pipe is preferably disposed on the inlet side of the inner cylinder with respect to the chlorine-containing synthetic resin supply pipe.

FIG. 3 shows an example of the overall configuration of the apparatus. The resin material to be processed and the solid heat medium are supplied from the inlet side of the pyrolysis furnace 9 to the processing space 12 via the quantitative supply devices 16 and 17. Since the pyrolysis is performed in an inert gas atmosphere, the inlet side and the outlet side of the pyrolysis furnace 9 are configured to prevent the free entry of the air. The heating gas is supplied to the heating gas passage 13 through the hot air inlet 18. The pyrolysis residue discharged from the apparatus main body 9 is supplied to the crushing means 6 by a transfer means (not shown).

On the other hand, the generated gas containing hydrogen chloride discharged from the pyrolysis furnace is supplied to a recovery means 5 such as a venturi scrubber or a water spraying device, in which case it is recovered as hydrochloric acid.

The heated gas flowing through the passage 13 is discharged from the other end of the pyrolysis furnace 9 through a discharge port 19. Heating space 1
The temperature of the chlorine-containing synthetic resin heated in 2 is 200 ° C.
The temperature is not less than 500 ° C., preferably 250 to 350 ° C., and more preferably about 300 ° C. If the temperature is lower than 200 ° C., the elimination reaction of hydrogen chloride is not efficiently performed, while
When the temperature exceeds 350 ° C., thermal decomposition of gas and liquid hydrocarbons starts to occur. When the temperature exceeds 500 ° C., the thermal decomposition occurs violently and is not desirable.

In the apparatus of the present invention, the heating gas flows outside the inner cylinder in which hydrogen chloride is generated, and thus the entire inner cylinder has the above-mentioned temperature of 200 to 500 ° C., so that even if hydrogen chloride comes into contact, the metal The corrosion effect of the inner cylinder is not large. In the temperature range where the temperature is 150 ° C. or less, metal corrosion is large. In the above temperature range, corrosion of the apparatus due to hydrogen chloride, particularly corrosion of each part of the inner cylinder, is appropriately prevented.

The crushing means (not shown) crushes the solid heat medium discharged from the pyrolysis means and the aggregates of the pyrolysis residue made of solid carbon or hydrocarbon from which chlorine has been removed into a shape suitable for reuse. Has the function of crushing. The means may be a crushing method using a cutter or a crushing method using an impact. The particle size of the pyrolysis residue after crushing is preferably 20 mm or less for charging in a heating furnace or a blast furnace.

[0039]

FIG. 4 shows the results of a treatment test of the chlorine-containing synthetic resin of the present invention. In Examples 1 to 4, a film-like chlorine-containing synthetic resin and a solid chlorine-containing synthetic resin were blended and supplied, and after pyrolysis, a pyrolysis residue having a particle size of 10 mm or less was obtained. In this case, the solid heat medium has a particle size of 20 mm.
The following coke was used. The conditions for the thermal decomposition were adjusted so that the outlet temperature of the inner cylinder became 350 ° C. by external heating. The area filling rate of the mixture of the chlorine-containing synthetic resin and the solid heat medium in the inlet cross section of the pyrolysis furnace was set to be 10%.

Since the above thermal decomposition was performed in a nitrogen gas atmosphere, the composition of the other gas components except for the nitrogen gas was as follows. The following numerical values are based on volume. _{HCl: 96.38%, CH 4:} 740ppm, C 2 H 4: 3158ppm, C 2 H 6: _{203ppm, C 3: 388ppm, C} 4: 656ppm, benzene: 30862Ppm, toluene: main gas components as described above 176ppm is hydrogen chloride.

When the solid chlorine-containing synthetic resin was thermally decomposed, a test was conducted without using any volume reducing means. As shown in FIG. 4, the chlorine content in the pyrolysis residue is 2 wt% or less,
Sufficient dechlorination was obtained. All of the obtained pyrolysis residues could be used as fuel for a heating furnace, or fuel or a reducing material for a blast furnace.

In the test of the comparative example, the film-based chlorine-containing synthetic resin was thermally decomposed without reducing the volume, but the material was suspended in a fixed amount supply device (hopper), and deposits were generated in the pyrolysis furnace. In addition, a large amount of tar was generated due to decomposition of the chlorine-containing synthetic resin, and stable treatment could not be performed.

[0043]

As described above, it is possible to treat a chlorine-containing synthetic resin by the method and apparatus of the present invention,
It can prevent the hanging of the shelves at the time of constant supply due to the film-like chlorine-containing synthetic resin, which has been a problem in the past, a decrease in operating efficiency, and the adhesion to the pyrolysis furnace. It became possible to process synthetic trees at the same time. In addition, since the pyrolysis residue can be used as a fuel or a reducing material for a heating furnace or a blast furnace, it has an extremely large industrial effect.

[Brief description of the drawings]

FIG. 1 is a diagram showing the entire process of the present invention.

FIG. 2 is a diagram showing a detailed structure of a pyrolysis furnace.

FIG. 3 is a diagram showing a specific configuration of the thermal decomposition device of the present invention.

FIG. 4 is a view showing the results of tests of the present invention example and a comparative example.

[Explanation of symbols]

 1, 2 crushing means 3 volume reducing means 4 thermal decomposition means 5 hydrogen chloride recovery means 6 crushing means 7 sieving means 9 thermal decomposition furnace 10 outer cylinder 11 inner cylinder

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-53-101074 (JP, A) JP-A-7-316339 (JP, A) JP-A-7-286062 (JP, A) JP-A-56-106 122894 (JP, A) JP-A-59-120682 (JP, A) JP-A-56-11912 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29B 17/00-17 / 02 C08J 11/00-11/28 C10L 5/00-11/08

Claims (1)

(57) [Claims] 1. A film-like chlorine-containing synthetic resin is pulverized in advance and further reduced in volume, and then together with a solid heat medium composed of coke, coal or a mixture thereof in an inert gas atmosphere at a temperature of 200 ° C. or more and 500 ° C. or less. The film-form chlorine is produced by heating in a rotary kiln and thermally decomposing the chlorine contained in the film-form chlorine-containing synthetic resin into hydrogen chloride, obtaining a pyrolysis residue and producing a raw material for a blast furnace. Treatment method for contained synthetic resin.