JP2003096469A - Reductive oiling system for waste plastic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reductive oiling system for waste plastics which ensures a sufficient oiling ability and facilitates stirring operations in a melting tank, cleaning and maintenance in a thermal decomposition tank. SOLUTION: This reductive oiling system for waste plastic has the melting tank 2 which has the first crucible 4 received on the inside of the first coil 3 and in which a high frequency electric current is allowed to flow in the first coil 3 to induce-heat the first crucible 4, thus melting a waste plastic in the first crucible 4 to obtain the melted plastic, and the thermal decomposition tank 5 which has the second crucible 7 received on the inside of the first coil 6 and in which a high frequency electric current flows in the first coil 3 to induction-heat the second crucible 7, thus thermally decomposing the melted plastic in the second crucible 4 to produce the decomposition gas G.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste plastic oil reduction apparatus for recycling waste plastic.

[0002]

2. Description of the Related Art Conventionally, there is known an oil reduction apparatus for heating waste plastic (polymer waste) to thermally decompose it and then reducing it into heavy oil (corresponding to heavy oil A). This type of oil reduction equipment is capable of treating solid waste plastics such as polyethylene, polysterol and vinyl chloride at a relatively low temperature of 250 ° C.
(Vinyl chloride is about 70 ° C) It is melted in a melting tank that is heated, and then, the decomposed waste plastic is thermally decomposed in a thermal decomposition tank that is heated to a high temperature of around 450 ° C (vinyl chloride is 170 ° C). This is a method for obtaining heavy oil by cooling vaporized cracked gas, and the applicant of the present invention has already disclosed that the oil of waste plastic suitable for recycling such waste plastic is disclosed in JP-A-10-219260. A chemical reduction device was proposed.

This oil reduction apparatus has a tank main body whose front surface is inclined and whose bottom surface side is narrowed. By providing a partition inside the tank main body, the thermal decomposition chamber can be located in front of the partition. A dissolution chamber is formed behind the partition part, and a communication space is formed below the partition part. Inside the tank body, a plurality of spaces are arranged at predetermined intervals in the vertical and horizontal directions, and have a ventilation path in the front-back direction. Since it is configured with a heating pipe, and the thermal decomposition tank also serves as a melting tank, the overall size of the device can be made compact and the cost can be significantly reduced, and the processing speed for waste plastic can be increased to increase the productivity of heavy oil. And the economical efficiency at the time of production can be improved.

However, in this oil reduction apparatus, since a plurality of heating pipes arranged at predetermined intervals in the vertical direction and the horizontal direction are provided inside the tank main body, sufficient stirring in the dissolution tank cannot be performed, There is a problem to be solved in that the dissolution efficiency is deteriorated, and it is not easy to remove the slag (residue) after pyrolysis adhering to the inside of the pyrolysis tank, which makes cleaning and maintenance difficult.

The present invention has solved the problems existing in the prior art as described above, and in particular, while improving the oily reduction capacity for waste plastics, in particular, the improvement of the dissolution efficiency in the dissolution tank and the thermal decomposition tank are achieved. It is an object of the present invention to provide an oil liquefaction reduction device for waste plastic, which can facilitate cleaning and maintenance of the waste plastic.

[0006]

Means and Embodiments for Solving the Problems The present invention constitutes an oil plasticizing and reducing apparatus 1 for waste plastics, which heats and thermally decomposes waste plastics, cools the generated decomposition gas G, and oilizes the waste plastics. At this time, the first crucible 4 is housed inside the first coil 3, and the first crucible 4 is induction-heated by flowing a high-frequency current through the first coil 3 to generate the first crucible 4.
The second crucible 7 has a melting tank 2 for melting the waste plastic put in the container to obtain a melted plastic, and a second crucible 7 housed inside the second coil 6, and by supplying a high frequency current to the second coil 6. Is characterized by including a thermal decomposition tank 5 for inductively heating and thermally decomposing the molten plastic contained in the second crucible 7 to generate decomposition gas G.

In this case, according to a preferred embodiment, the dissolution tank 2 has a stirring mechanism 1 for stirring the inside of the first crucible 4.
1 is attached and the pyrolysis tank 5 has a second crucible 7
Scraping mechanism 12 for scraping off slag (residues) attached to the inner wall of the
Can be attached. On the other hand, in the oil reduction unit 1,
The terephthalic acid generated during the thermal decomposition of the polyethylene terephthalate molded product is heated at a high temperature of 300 ° C or higher,
And a terephthalic acid decomposing unit M for obtaining a decomposition product of benzene, benzoic acid and carbon dioxide by contacting with a catalyst C using an acid or a base, and an oil tank 15 accommodating a high temperature oil X, By inserting the Styrofoam S into the oil tank 15, it is possible to provide the Styrofoam pretreatment device 16s for obtaining the melt Sm of the Styrofoam S. The oil X may be edible waste oil.

As a result, in the melting tank 2, the first coil 3
By inductively heating the first crucible 4 by flowing a high-frequency current into the first crucible 4 to heat the first crucible 4 itself, for example, by heating the inside of the first crucible 4 to about 200 to 300 [° C.], The waste plastic put into the first crucible 4 can be melted. In this case, since there are no obstacles inside the first crucible 4, it is possible to easily and sufficiently stir the dissolved waste plastic (dissolved plastic) by providing the stirring mechanism section 11. On the other hand, in the thermal decomposition tank 5, a high frequency current is passed through the second coil 6 to inductively heat the second crucible 7 to generate heat in the second crucible 7 itself. If heated to about 400-500 [° C],
The molten plastic supplied to the second crucible 7 can be thermally decomposed. In this case, since there are no obstacles inside the second crucible 7, by attaching the scraping mechanism section 12, it is possible to easily scrape off the slag attached to the inner wall of the second crucible 7.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, preferred embodiments according to the present invention will be described in detail with reference to the drawings.

First, the structure of the oil reduction apparatus 1 according to this embodiment will be described with reference to FIGS.

1 and 2 show the entire system configuration of the oil reduction apparatus 1. This oil reduction unit 1 comprises a dissolution tank 2 and a thermal decomposition tank 5. The dissolution tank 2 is, as shown in FIG.
A first crucible 4 is arranged inside the first coil 3.
At this time, a predetermined space is interposed between the first coil 3 and the first crucible 4. The first crucible 4 is made of iron, alumina, or the like in a pot shape, and the outer surface of the first crucible 4 is covered with a refractory material 21 such as magnesia spinel.
The refractory material 21 is covered with a flexible mica plate 22, and the first coil 3 is mounted on the mica plate 22. The periphery of the first coil 3 is covered with the heat insulating material 23. As a result, the melting tank 2 is constructed in which the first crucible 4 is induction-heated by applying a high-frequency current to the first coil 3 and the waste plastic contained in the first crucible 4 is melted to obtain molten plastic.

In addition, as shown in FIG.
A stirring mechanism section 11 for stirring the inside of the first crucible 4 is attached. In the melting tank 2, since the first crucible 4 itself generates heat due to induction heating, there are no obstacles inside the first crucible 4. Therefore, for example, if the rotation drive unit (drive motor) 24 is arranged outside and the stirring mechanism unit 11 in which the stirring blades 25 rotated by the rotation drive unit 24 are arranged inside the first crucible 4, is provided. The dissolved waste plastic can be easily and sufficiently stirred, and the dissolution efficiency can be improved.

On the other hand, the thermal decomposition tank 5 is, as shown in FIG.
A second crucible 7 is arranged inside the second coil 6 to be configured.
The thermal decomposition tank 5 has the same basic configuration as the above-described melting tank 2, except that the size (volume) is increased by about 1.5 to several times. As a result, a thermal decomposition tank 5 is constructed in which a high-frequency current is passed through the second coil 6 to inductively heat the second crucible 7, and the molten plastic contained in the second crucible 7 is thermally decomposed to generate decomposition gas G. It

Further, as shown in FIG. 1, the thermal decomposition tank 5 is provided with a scraping mechanism portion 12 for scraping off the slag (residue) attached to the inner wall of the second crucible 7. In the thermal decomposition tank 5, the second crucible 7 itself generates heat due to induction heating.
Similarly, there are no obstacles inside the second crucible 7. Therefore, for example, the rotation drive unit (drive motor) 26 is provided outside, and the scraping mechanism unit 12 having the scraping blade 27 rotated by the rotation drive unit 26 is provided inside the second crucible 7. For example, it is possible to easily scrape off the slag that remains on the inner wall after thermal decomposition, and facilitate cleaning and maintenance.

An example of installation of the melting tank 2 and the thermal decomposition tank 5 is shown in FIG. In the figure, 70 is an installation table, and the dissolution tank 2 and the thermal decomposition tank 5 are installed side by side on this installation table 70. On this occasion,
The melting tank 2 is installed above the upper surface of the installation table 70 by a predetermined height by the support frames 71. In addition, the bottom surface of the melting tank 2 and the bottom surface of the thermal decomposition tank 5 are connected to each other by an inclined communication pipe 7
An on-off valve 73 is attached in the middle of the communication pipe 72. Reference numeral 74 indicates a ladder attached to the installation table 70.

On the other hand, the melting tank 2 has a lid 75, and the lid 7
5 is provided with a charging port (hopper) 28 for charging the waste plastic inside the first crucible 4, and the lid 75 is further generated inside the melting tank 2 as shown in FIG. Hydrochlorination part 29 for hydrochloric acid of chlorine gas, PH for neutralizing hydrochloric acid obtained by this hydrochloric acid treatment part 29
The neutralization processing unit 30 is sequentially connected. In addition, a conveyor 31 for carrying waste plastic is introduced into the input port 28 if necessary.
Can be attached, and if necessary, a pretreatment device 16 for pretreatment of waste plastic can be installed. Pretreatment device 1
As 6, a crusher for crushing solid waste plastic into small pieces, a styrene foam pretreatment device for melting styrene foam, or the like can be used.

As an example of the pretreatment device 16, a styrofoam pretreatment device 16s is shown in FIG. The styrofoam pretreatment device 16s has an oil tank 15, and the oil X is stored in the oil tank 15. For this oil X, edible waste oil (plant waste oil) can be reused. The oil tank 15 contains oil X at a high temperature (220
A heating unit 91 for heating to about [° C.] is incorporated. The heating unit 91 can be configured by an induction heating method using the coil 91c. Further, an opening / closing valve 92 is provided on the bottom surface of the oil tank 15.
A discharge part 93 provided with is provided. A receiver V can be set below the discharge part 93. Further, a ventilation unit 94 is attached to the oil tank 15. Ventilation unit 94
Includes an intake duct 95 arranged above the oil tank 15, a deodorizing chamber 96 for mainly removing odors in the exhaust A sucked from the intake duct 95, and an exhaust duct 97 connected to the upper part of the deodorizing chamber 96. In this case, in the deodorizing chamber 96, a shower is jetted to the first deodorizing section 98 for deodorizing the exhaust A sucked from the intake duct 95 by passing it through activated carbon or the like, and the exhaust A passing through the first deodorizing section 98. The second deodorizing unit 99 for deodorizing is provided. An intake fan 100 is attached to the exhaust duct 97.

Thus, when the expanded polystyrene S, which is waste plastic, is put into the oil X contained in the oil tank 15, the expanded polystyrene S is melted by the oil X heated to a high temperature, and a melt Sm obtained from this is obtained. Settles on the bottom of the oil tank 15. Therefore, if the melt Sm is accumulated to some extent, the open / close valve 92 is opened to open the discharge portion 9
The melt Sm can be discharged to the receiver V through 3. Therefore, when the obtained melt Sm is charged into the charging port 28, the melt Sm contains an oil component of about 30%, so that the oxidation is reduced and a good thermal decomposition treatment can be performed. it can.

On the other hand, the thermal decomposition tank 5 has a lid 76, and an air supply duct 77 for sending the decomposition gas G generated inside the second crucible 7 to the next step (scrubber 34) is connected to the lid 76. . A discharge pipe 78 is connected to the center of the bottom of the second crucible 7, and a residue treatment unit 32 is connected to the lower end outlet of the discharge pipe 78. Reference numeral 33 denotes an opening / closing valve attached to the discharge pipe 78.

On the other hand, a scrubber 34 with a pH adjusting tank 35 is connected to the tip of the air supply duct 77, and
A terephthalic acid decomposer M for decomposing terephthalic acid in the decomposition gas G is connected to the outlet of the scrubber 34. By the way, when a polyethylene terephthalate (PET) molded product such as a PET bottle is thermally decomposed as waste plastic, a large amount of terephthalic acid is contained in the decomposition gas G.
When it is directly supplied to 6, the terephthalic acid is crystallized by the cooling of the condenser unit 36, and the heat exchange pipe in the condenser unit 36 frequently has a problem such as pipe clogging. Therefore, the decomposition gas G is supplied to the terephthalic acid decomposition device M, and the terephthalic acid is decomposed into a low boiling point compound which does not crystallize by gas phase decomposition.

FIG. 6 shows a specific structure of the terephthalic acid decomposition apparatus M. In the figure, 51 is a mixing unit for mixing the water W with the decomposition gas G, and this water W is supplied via a water amount adjusting unit 52 for adjusting the amount of water. Reference numeral 50 denotes a decomposition tank, which is configured by housing the catalyst C in a heating furnace (electric furnace) 53. As a result, the decomposition gas G applied from the mixing section 51 comes into contact with the catalyst C and is then discharged. An acid or a base is used as the catalyst C, and the acid is 300 to 4
Silica alumina formed into particles of 00 [μm] is fired at 600 [° C.] as a base to give 300 to 400.
Calcium oxide-zinc oxide (CaO
/ ZnO) is used. Further, the heating furnace 53 has the ability to heat the decomposition gas G which comes into contact with the catalyst C to a reaction temperature of about 500 [° C.]. Reference numeral 54 denotes a temperature control unit that controls the heating temperature of the heating furnace 53, and 55 denotes a switching valve.

On the other hand, 36 is the decomposition gas G which has passed through the catalyst C.
Is a condenser unit that is supplied with decomposition gas G
Is cooled by the condenser unit 36 and liquefied.
In FIG. 1, 37 is a cooling tower for cooling the condenser unit 36, 38 is a circulation pump for circulating cooling water, 39 is a water supply source, and water is supplied from the water supply source 39 to the cooling tower 37 and the water amount adjusting unit 52. It Further, 40 is an oil storage tank in which the heavy oil obtained by the condenser unit 36 is stored. Since water is generated in the condenser unit 36 in addition to heavy oil, an oil / water separation tank and a filter for separating heavy oil and water are built in the condenser unit 36.

Next, the overall operation of the oil reduction apparatus 1 according to this embodiment will be described with reference to FIGS.

First, a high-frequency current is passed through the first coil 3 of the melting tank 2 and the second coil 6 of the thermal decomposition tank 5 to make the first crucible 4
And induction heating the second crucible 7. In this case, the temperature of the first crucible 4 is 200 to 30 which is necessary for melting the waste plastic.
0 [° C.] (70 [° C.] for vinyl chloride), and the temperature of the second crucible 7 is 400 to 500 [° C.] (17 ° C. for vinyl chloride) required for thermal decomposition of molten plastic.
0 (° C)). The open / close valve 74 is closed.

Then, the waste plastic is charged into the melting tank 2 through the charging port 28. In this case, the waste plastic is pretreated by the pretreatment device 16 if necessary, and then is thrown into the charging port 28. For example, in the case of a large solid waste plastic (polyethylene, polysterol, etc.), it is crushed by a crusher, and in the case of Styrofoam S, it is charged as a melt Sm by the above-described Styrofoam pretreatment device 16s. You can

On the other hand, the waste plastic put into the melting tank 2 is melted by being heated at a set temperature. At this time, when vinyl chloride is added as waste plastic, chlorine gas is generated during melting, so the generated chlorine gas is supplied to the hydrochloric acid treatment unit 29 to be converted into hydrochloric acid, and the obtained hydrochloric acid is added to PH. It is supplied to the neutralization processing unit 30 for neutralization.

When the waste plastic in the dissolution tank 2 is dissolved to some extent, the rotation drive unit 24 of the stirring mechanism unit 11 is operated and the stirring blades 25 are rotated to perform stirring.
Since there are no obstacles inside the first crucible 4, it is possible to easily and sufficiently stir the dissolved waste plastic (dissolved plastic), and it is possible to enhance the dissolution efficiency. Then, when it is sufficiently melted, the open / close valve 73 is opened, and the melted plastic is poured into the thermal decomposition tank 5.

The molten plastic supplied to the thermal decomposition tank 5 is thermally decomposed by being heated at a set temperature. The decomposition gas G generated by the thermal decomposition is the air supply duct 7
7 is supplied to the scrubber 34 and the harmful gas in the decomposition gas G is neutralized by the shower of the sodium hydroxide solution. The neutralized decomposition gas G is supplied to the terephthalic acid decomposition device M or the condenser unit 36. In this case, when the waste plastic is a polyethylene terephthalate molded product such as a PET bottle, the decomposition gas G is supplied to the terephthalic acid decomposition apparatus M by switching the switching valve 55, and when the waste plastic is other than this, switching is performed. By switching the valve 55, the decomposition gas G is directly supplied to the condenser unit 36.

Next, the operation of the terephthalic acid decomposition apparatus M will be described. If the decomposition gas G containing terephthalic acid is supplied to the terephthalic acid decomposition device M, first, the mixing section 51
Accordingly, an appropriate amount of water W supplied from the water amount adjusting unit 52 is added to the decomposition gas G. In this case, the water content W is changed to steam and mixed. The decomposition gas G that has passed through the mixing section 51 is
Pass through catalyst C with acid (silica alumina) or base (calcium oxide-zinc oxide). At this time, the decomposition gas G containing terephthalic acid is heated at a high temperature of 300 [° C.] or higher, preferably about 500 [° C.]. As a result, terephthalic acid comes into contact with the catalyst C at high temperature and is supplied to the condenser unit 36 in the next step.
When cooled by the condenser unit 36,
Decomposition products containing mainly benzene, benzoic acid and carbon dioxide are obtained. The carbon dioxide is due to the decomposition of the carboxyl group of terephthalic acid.

As described above, when the polyethylene terephthalate molded product is pyrolyzed, a large amount of terephthalic acid is generated. However, since terephthalic acid is a sublimable high-boiling compound, when it is directly supplied to the condenser unit 36,
As described above, a crystallization product (low boiling point compound) which is crystallized in the condenser unit 36 and causes a problem such as a tube clogging, is decomposed in the gas phase by passing through the terephthalic acid decomposition device M and does not cause crystallization. Convert to.

FIG. 7 shows the ratio of the decomposition products to the heating temperature when terephthalic acid before passing through the catalyst C is 100% by weight. Note that FIG. 7 shows data when calcium oxide-zinc oxide is used as the catalyst C and the water content W mixed in the decomposition gas G is zero. As is clear from the figure, if the temperature is approximately 300 [° C.] or higher, a certain effect can be obtained, and at around 500 [° C.],
It can decompose virtually all terephthalic acid.

Further, FIG. 8 shows the ratio of decomposition products to the amount of water W to be mixed when terephthalic acid before passing through the catalyst C is 100% by weight.
Note that FIG. 8 shows data when calcium oxide-zinc oxide is used as the catalyst C and the temperature (reaction temperature) for heating the decomposition gas G is 430 [° C.]. As is clear from the figure, when an appropriate amount of water W is mixed with the decomposition gas G, the conversion rate decreases, but the benzoic acid selectivity increases. Therefore, when the conversion rate is important, the mixing section 5
It is desirable that the amount of water W added by 1 is set to 0, but when importance is attached to the selectivity of benzoic acid, the decomposition gas G
On the other hand, an appropriate amount of water W can be mixed, and the amount of water W to be mixed can be adjusted to set the selectivity arbitrarily.

When comparing the silical alumina used as the catalyst C with the calcium oxide-zinc oxide, experimentally, the calcium oxide-zinc oxide has a higher activity than the silical alumina, and the calcium oxide is practically used. -It is desirable to use zinc oxide.

On the other hand, the decomposition gas G passing through the terephthalic acid decomposition apparatus M is supplied to the condenser unit 36, and the decomposition gas G obtained by treating the waste plastic other than the polyethylene terephthalate molding is supplied from the scrubber 34 to the condenser unit 36. Directly supplied. Then, the decomposed gas G is liquefied into heavy oil (corresponding to heavy oil A) by being cooled (heat exchange) by the condenser unit 36. The condenser unit 36 is constantly cooled by the cooling liquid sent from the cooling tower 37. Then, the obtained heavy oil is stored in the oil storage tank 40.

By the way, since the thermal decomposition tank 5 performs thermal decomposition treatment on the molten plastic, slag (residue) is likely to adhere to the inner wall of the second crucible 7. In this case, at the time of cleaning (maintenance), the rotation driving unit 26 of the scraping mechanism unit 12 is drive-controlled to rotate the scraping blade 27, so that the slag (residue) remaining on the inner wall of the second crucible 7 remains. It can be easily scraped, and cleaning and maintenance can be performed easily. In addition, at this time, by opening the opening / closing valve 33, the scraped scraps are stored in the residue treatment unit 30 through the discharge pipe 78, and the scraps stored in the residue treatment unit 30 are heated to a high temperature (about 550 to 600 [° C.]). ) To burn off.

The embodiment has been described in detail above.
The present invention is not limited to such an embodiment,
The detailed configuration, shape, material, quantity, numerical value, method, etc. can be arbitrarily changed, added, or deleted without departing from the scope of the present invention.

[0037]

As described above, the waste plastic oil reduction apparatus according to the present invention has the first crucible arranged inside the first coil, and the high frequency current is passed through the first coil. And a melting tank for inducing heat to melt the waste plastic contained in the first crucible to obtain the melted plastic,
It has a second crucible placed inside the second coil.Induction heating of the second crucible by passing a high-frequency current through the second coil causes thermal decomposition of the molten plastic contained in the second crucible to generate decomposition gas. Since it is equipped with a thermal decomposition tank for making it possible to secure a sufficient oil reduction capacity for waste plastic, in addition, it is possible to achieve sufficient stirring in the dissolution tank and easy cleaning and maintenance of the thermal decomposition tank. Produce an effect.

[Brief description of drawings]

FIG. 1 is a block system diagram of an oil reduction apparatus according to a preferred embodiment of the present invention,

FIG. 2 is a schematic configuration diagram of the oilification reduction apparatus,

FIG. 3 is a front view showing an example of installation of a dissolution tank and a thermal decomposition tank in the oil reduction apparatus.

FIG. 4 is a cross-sectional configuration diagram of a dissolution tank in the oil reduction apparatus.

FIG. 5 is a cross-sectional configuration diagram of a Styrofoam pretreatment device in the oilification reduction device,

FIG. 6 is a block system diagram of a terephthalic acid decomposing unit in the oil reduction unit,

FIG. 7 is a data diagram showing the ratio of decomposition products to heating temperature in the terephthalic acid decomposition apparatus,

FIG. 8 is a data diagram showing the ratio of decomposition products to the amount of water mixed in the decomposition gas in the terephthalic acid decomposition apparatus,

[Explanation of symbols]

1 Oilification reduction device 2 Melting tank 3 first coil 4 first crucible 5 Thermal decomposition tank 6 second coil 7 Second crucible 11 Stirring mechanism 12 Scraping mechanism 15 oil tank 16s Styrofoam pretreatment device G decomposition gas C catalyst M terephthalic acid decomposer S Styrofoam Sm melt X oil

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08L 67:00 C08L 67:00 (71) Applicant 593116401 Shinichi Yoshimura 91-10 Matsushiro Matsushiro, Nagano City, Nagano Prefecture ( 72) Inventor, Yoshimura, 9-10 Matsushiro, Matsushiro-cho, Nagano-shi, Nagano 3-10F Term (reference) 3K059 AB15 AB16 AD03 4F301 AA13 AA15 AA17 AA25 BF11 BF15 BF20 BF23 BF25 BF29 BF40 CA12 CA24 CA26 CA46 CA52 CA53 CA65 CA67 CA68 CA74 CA74 CA29 CA74 CA74 CA29 CA74 CA12 CA16

Claims (6)

[Claims] 1. A waste plastic oil reduction apparatus which heats and thermally decomposes waste plastic, cools the generated decomposition gas and oilizes the waste plastic, and has a first crucible arranged inside a first coil, A melting tank for inductively heating the first crucible by flowing a high-frequency current in the first coil to melt the waste plastic contained in the first crucible to obtain a melted plastic, and a second tank disposed inside the second coil. A thermal decomposition tank that has two crucibles, inductively heats the second crucible by applying a high-frequency current to the second coil, and thermally decomposes the molten plastic contained in the second crucible to generate decomposition gas. An apparatus for oily reduction of waste plastic, characterized by being provided. 2. The apparatus for oil-reducing waste plastic according to claim 1, wherein the melting tank is provided with a stirring mechanism section for stirring the inside of the first crucible. 3. The apparatus for oil-reducing waste plastics according to claim 1, wherein the thermal decomposition tank is provided with a scraping mechanism section for scraping off slag adhering to the inner wall of the second crucible. 4. Benzene, benzoic acid and dioxide are obtained by heating terephthalic acid generated during thermal decomposition of a polyethylene terephthalate molded product at a high temperature of 300 [° C.] or higher and bringing it into contact with a catalyst using an acid or a base. The oil liquefaction reduction device for waste plastic according to claim 1, further comprising a terephthalic acid decomposition device for obtaining a decomposition product of carbon. 5. The styrene foam pretreatment device having an oil tank containing high-temperature oil, the styrene foam pretreatment device for obtaining a melt of the styrene foam by charging the styrene foam into the oil tank. Oil reduction equipment for waste plastic. 6. The oil plasticizer for waste plastic according to claim 5, wherein the oil is edible waste oil.