JPH10259273A - Chlorine removal from chlorine-containing polymeric resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain high treatment efficiency in chlorine removal from chlorine- containing resin by means of a rotary kiln by using the thermal medium continuously after dechlorination treatment without separation from the waste resin as a feedstock for the kiln, as the heat medium is prevented from segregation. SOLUTION: The material to be treated comprising partially or wholly a chlorine-containing polymer resin material is fed to a path 4 inside the rotary kiln together with the heat medium and hot gas is blown in the same path 4 to effect the dechlorination from the chlorine-containing polymer resin. At this time, as a heat medium to be fed together with the material to be treated, iron source for the furnace, an iron source reducing agent, one or more kinds of powder particles that can be used as a fuel or auxiliary feedstock, particularly powdery coke and/or granular thermosetting resin are used. Since the heat medium is the particles used in the furnace, it can be used as an iron source reduction agent or as a fuel in no need of separation into the treated resin material and the heat medium. Thus, the segregation of the heat medium is inhibited to attain high treatment efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing chlorine from a chlorine-containing polymer resin such as vinyl chloride.

[0002]

2. Description of the Related Art In recent years, synthetic resins such as plastics have been rapidly increasing as industrial wastes and general wastes, and their disposal has become a serious social problem. Among them, plastics, which are high-molecular hydrocarbon compounds, generate a large amount of heat when they are burned, and when incinerated in a general incinerator, damage the furnace walls etc., making mass treatment difficult, and most of them are landfills. It is currently dumped on land. However, dumping of plastics etc. is not preferable for environmental measures,
Further, recently, shortage of land for landfill is becoming a social problem, and therefore, development of a method for mass processing of synthetic resins that does not rely on dumping is keenly desired.

Against this background, a method using synthetic resins such as plastics as an auxiliary fuel for a blast furnace or the like or a reducing agent for an iron source is disclosed in, for example, European Patent Publication No. 06224.
65A1 and JP-B-51-33493. However, it is said that about 15% of chlorine-containing polymer resin such as vinyl chloride is contained in waste synthetic resin on average, and when such synthetic resin is supplied to a blast furnace or the like, A large amount of harmful gas (HCl) is generated by thermal decomposition and combustion of the chlorine-containing polymer resin, causing significant environmental pollution. Therefore, in order to prevent the generation of such harmful gases, it is necessary to separate the chlorine-containing polymer resin from the synthetic resins in advance and remove chlorine (dechlorination treatment) from the chlorine-containing polymer resin. is there.

Conventionally, a method using a rotary kiln is known as a method for dechlorinating a chlorine-containing polymer resin. This method supplies chlorine-containing polymer resin material and sand as a heat carrier inside the rotary kiln,
Heating gas is supplied as a heat source, and the chlorine-containing polymer resin is mixed with sand by rotation of the kiln for about 250 to 3 hours.
The resin is heated to about 50 ° C., and this heating causes a elimination reaction in which chlorine in the resin is eliminated as hydrogen chloride, and hydrogen chloride gas is generated. The hydrogen chloride gas is discharged to the outside of the kiln together with the heating gas, and the residue of the chlorine-containing polymer resin (residual solid matter of the resin) after the dechlorination treatment is also discharged to the outside of the kiln together with the sand as the heat medium.

[0005]

However, when the residue of the dechlorinated resin material is blown into a melting furnace such as a blast furnace or used as a raw material (mainly, a reducing agent or fuel for an iron source), a heat medium is required. In the above-described conventional technique using sand as the material, it is necessary to separate the sand from the residue of the resin material after the dechlorination treatment is completed, and this treatment causes an increase in equipment cost and treatment cost.

Further, the form of the chlorine-containing polymer resin material is various, such as a lump or a film, and the density of the synthetic resin is about 1, while the density of the sand is about 2-3, Since there is a remarkable difference in specific gravity between the two, the sand tends to segregate in the rotary kiln, so that the sand does not function effectively as a heat carrier and the processing efficiency is low. When the ratio of the chlorine-containing polymer resin material to the sand (chlorine-containing polymer resin material / sand) is 1 or less, thermal decomposition of the resin material to lower hydrocarbons easily occurs. Since the lower hydrocarbon gas is contained together with the hydrogen gas, the processing cost of the exhaust gas also increases.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve such problems of the prior art, and to separate a heat medium from a residue of a resin material after dechlorination treatment in removing chlorine from a chlorine-containing polymer resin by a rotary kiln method. An object of the present invention is to provide a method for removing chlorine from a chlorine-containing polymer resin, which can be used as a raw material for a furnace (such as a fuel or an iron source reducing agent) without any modification. Another object of the present invention is to prevent the segregation of the heat medium, effectively function the heat medium to obtain high treatment efficiency, and also effectively suppress the thermal decomposition of the resin material into lower hydrocarbons. To provide a method for removing chlorine from a chlorine-containing polymer resin.

[0008]

The features of the present invention for solving such a problem are as follows. (1) Using a rotary kiln-type chlorine removing device, supply the material to be treated, which is partially or entirely made of a chlorine-containing polymer resin material, together with the heat medium into the passage of the rotary kiln, and flow the heating gas through the same passage. In the method for removing chlorine from chlorine-containing polymer resin by dechlorination of chlorine-containing polymer resin material, as a heat medium to be supplied together with the material to be treated, as a furnace iron source, iron source reducing agent, fuel or auxiliary material A method for removing chlorine from a chlorine-containing polymer resin, comprising using one or more kinds of particles selected from usable particles.

(2) In the method for removing chlorine according to the above (1), the powdery or granular material used as the heat medium is at least one selected from coke breeze, ore, ore powder, sintered powder and particulate thermosetting resin. A method for removing chlorine from a chlorine-containing polymer resin, which is a granular material. (3) The method for removing chlorine according to the above (1), wherein the granular material used as the heat medium is at least one type of granular material selected from coke breeze and granular thermosetting resin. Method for removing chlorine from chlorine-containing polymer resin. In the present invention, the material to be treated does not prevent the inclusion of resins other than the chlorine-containing resin, composite materials of the chlorine-containing resin and other materials, and materials other than the resin.

[0010]

FIG. 1 is a block diagram showing an embodiment of the present invention.
And FIG. 2 as an example, 1 is a rotary kiln main body in the figure, and this rotary kiln main body 1 is composed of a refractory 2 and a steel shell 3, and the inside of the rotary kiln main body 1 is used for dechlorination while transferring a resin material to be processed. The passage 4 is constituted.

In the passage 4 of the rotary kiln main body 1, a material to be treated, which is partially or entirely a chlorine-containing polymer resin material from one end side thereof (hereinafter, a case where the material to be treated is substantially composed of only a resin material). (Described in the example), a heating medium is supplied, and a heating gas is supplied as a heat source. The heating gas heats the entire kiln and heats the resin material to be processed and the heat medium. Further, the solid heat medium not only heats the resin material to be treated, but also disperses in the resin material to be treated, thereby suppressing fusion and agglomeration of the resin materials to be treated, thereby improving the dechlorination efficiency. The resin material to be treated is heated while being mixed with the heat medium by the rotation of the kiln, and this heating causes a reaction in which chlorine in the chlorine-containing polymer resin material is desorbed as hydrogen chloride, and hydrogen chloride gas is generated.

In the present invention, as a heat medium supplied into the passage 4 together with the resin material to be treated in such a dechlorination treatment, at least one kind of iron source, iron source reducing agent, fuel or auxiliary material of the furnace that can be used. Use granules. Thus, the residue of the resin material after the dechlorination treatment can be supplied as it is to the melting furnace or the like as a reducing agent of the iron source, fuel, or the like without being separated from the heat medium. Powders and granules suitable for such a heat medium include coke breeze, fine ore, sintered powder (granules of sintered ore), and particulate thermosetting resins (eg, phenolic resin, urea resin, urethane resin). And the like, and it is preferable to use one or more of these as a heat medium.

In order to prevent the segregation of the heat medium in the passage 4 and improve the heating efficiency, it is preferable that the heat medium has a particle diameter and specific gravity as close as possible to the resin material. Most preferably, coke breeze and / or particulate thermosetting resin is used as the heating medium. In addition, the use of coke breeze or a particulate thermosetting resin as a heat medium prevents segregation of the heat medium, thereby suppressing decomposition of the resin material into lower hydrocarbons.

The heating temperature of the resin material to be treated in the passage 4 is preferably set at 250 to 350.degree. C., more preferably around 300.degree. If the heating temperature is lower than 250 ° C., the elimination reaction of hydrogen chloride is not efficiently performed, while if it exceeds 350 ° C., thermal decomposition of the resin material into gaseous and liquid hydrocarbons starts to occur.

The heated gas flowing through the passage 4 and the hydrogen chloride gas desorbed from the resin material to be treated are discharged from the other end of the passage 4, and the hydrogen chloride gas in the discharged gas is recovered in a hydrogen chloride absorption building or the like. You. In addition, the residue of the resin material to be treated after the dechlorination treatment has been completed (residual solid matter of the thermally decomposed resin) is a heating medium (an iron source reducing agent for a furnace, at least one kind of powder or granules usable as a fuel or an auxiliary material). Is discharged out of the kiln together with the heat medium, and is used as it is as a reducing agent of an iron source, a fuel, etc. in a furnace such as a melting furnace without being separated.

FIG. 3 shows an example of the structure of a chlorine removing apparatus used for carrying out the present invention. One end of a rotary kiln body 1 having a passage 4 is provided with a supply port 6 for supplying a material. A screw feeder 5 and a hot air conduit 7 for supplying a heating gas (hot air) are connected. On the other end side of the rotary kiln body 1, a discharge device 8 for the treated resin material and the exhaust gas is provided. This discharging device 8
Has a resin residue outlet 9 at its lower part and an exhaust gas outlet 10 at its upper part. In other drawings, 11
, A hot air generator; and 12, a drive motor for the screw feeder 5.

According to such a chlorine removing apparatus, the resin material to be treated and the heat medium are supplied into the passage 4 from one end of the rotary kiln body 1 through the screw feeder 5, and the heating gas is supplied from the hot air conduit 7. You. In the passage 4, as described above, the resin material to be treated is dechlorinated, and a mixture of the exhaust gas (heating gas + hydrogen chloride gas), the residue of the resin material to be treated and the heat medium, which has been dechlorinated, The exhaust gas is discharged to the discharge device 8 at the other end of the rotary kiln main body 1, and the exhaust gas is discharged from the upper exhaust gas discharge port 10, and the mixture of the residue of the resin material to be treated and the heat medium is discharged from the lower discharge port 9. . The supply of the resin material to be processed and the heat medium to the rotary kiln main body 1 may be performed using separate supply devices.

[0018]

EXAMPLE A vinyl chloride resin material was subjected to dehydrochlorination using a chlorine removing apparatus having the structure shown in FIG. The structure of the chlorine removal apparatus used and the test conditions are as follows. -Equipment configuration Kiln dimensions: 600mm inner diameter x 3000mm length Tilt angle of rotary kiln body: 5 °-Test conditions Hot air temperature: 320 ° C Hot air supply: 3500Nm ³ / hr Kiln rotation speed: 1rpm

In this embodiment, as the resin material to be treated, chlorine content: 35 wt%, ash content: 2.5 wt%, carbon content: 56.53 wt%, hydrogen content: 5.96 wt
%, A vinyl chloride resin having a particle size of 10 to 20 mm was used. As the heat medium, coke breeze having a particle size of 10 mm or less was used in the present invention, and sand was used in the comparative example.

Inventive Example 1 and Comparative Example 1 After the weight ratio between the resin material supply amount and the heat medium supply amount was kept constant at 1/1, the resin material supply amount was changed to perform dechlorination treatment. Was examined for the dechlorination rate. FIG. 4 shows the results. ○ Inventive Example 2 and Comparative Example 2 After the resin material supply was fixed at 100 kg / hr, dechlorination was performed by changing the heating medium supply, and the resin material was dechlorinated and decomposed into lower hydrocarbons. The rate was checked. The result is shown in FIG.

According to FIG. 4 and FIG. 5, the segregation of the heating medium in the rotary kiln is prevented in the example of the present invention using coke breeze as the heating medium. The dechlorination treatment can be performed efficiently, and the decomposition rate (gasification rate) of the resin material into lower hydrocarbons is suppressed to be lower than the comparative example.

[0022]

As described above, according to the chlorine removing method of the present invention, since the powdery granules that can be used as a furnace charging material are used as a heat medium, the resin residue after the completion of the dechlorination treatment is removed. Without being separated from the heat medium, it can be directly supplied to various furnaces (especially melting furnaces) such as a blast furnace as a fuel or a reducing agent for an iron source. In particular, the use of coke breeze as a heating medium prevents segregation of the heating medium, thereby ensuring a high processing efficiency of the dechlorination treatment, and also has an effect of thermally decomposing the resin material into lower hydrocarbons. Can be suppressed.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the method of the present invention, and is an explanatory view showing a rotary kiln main body in a longitudinal sectional state.

FIG. 2 shows an embodiment of the method of the present invention, and is an explanatory diagram showing a rotary kiln main body in a cross-sectional state.

FIG. 3 is an explanatory diagram showing an example of a configuration of a chlorine removing apparatus provided for carrying out the present invention.

FIG. 4 is a graph showing a relationship between a supply amount of a resin material and a dechlorination ratio of the resin material for Example 1 of the present invention and Comparative Example 1 of the embodiment.

FIG. 5 shows the weight ratio of the supply amount of the resin material / the supply amount of the heating medium, the dechlorination rate of the resin material, and the decomposition rate (gasification rate) of the resin material to lower hydrocarbons in Example 2 of the present invention and Comparative Example 2. Graph showing the relationship

[Explanation of symbols]

1: rotary kiln body, 2: refractory, 3: iron skin, 4
... passage, 5 ... screw feeder, 6 ... supply port, 7 ...
Hot air conduit, 8 ... exhaust device, 9 ... outlet, 10 ... exhaust gas outlet, 11 ... hot air generator, 12 ... drive motor

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Koichi Tomioka 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Inside Nihon Kokan Co., Ltd.

Claims (3)

[Claims] 1. A rotary kiln-type chlorine removing apparatus is used to supply a material to be processed, which is partially or entirely made of a chlorine-containing polymer resin material, together with a heat medium into a passage of a rotary kiln, and to supply a heating gas into the same passage. In the method for removing chlorine from a chlorine-containing polymer resin in which the chlorine-containing polymer resin material is dechlorinated by flowing water, the iron source of the furnace, the iron source reducing agent, the fuel or the auxiliary A method for removing chlorine from a chlorine-containing polymer resin, comprising using one or more kinds of powders selected from powders that can be used as a raw material. 2. The powdery material used as the heat medium is at least one kind of powdery material selected from coke breeze, fine ore, sintered powder, and powdery thermosetting resin. Item 6. The method for removing chlorine from a chlorine-containing polymer resin according to Item 1. 3. The chlorine-containing substance according to claim 1, wherein the powdery substance used as the heat medium is at least one kind of powdery substance selected from coke powder and powdery thermosetting resin. Method for removing chlorine from polymer resin.