JP7499681B2 - Waste plastic processing system - Google Patents

Description

The present invention relates to a waste plastic processing system.

The low rate of effective utilization of waste plastics and environmental pollution caused by marine plastics have become global issues.
One method for recycling waste plastics is chemical recycling, and various studies have been conducted on chemical recycling technology.

For example, Patent Document 1 discloses a method that includes melting a plastic material (1) to form a plastic melt, degassing the plastic melt, and then sending the plastic melt to a depolymerization reactor (3), and adding a fraction obtained from crude oil as a solvent (6) to the plastic melt, thereby reducing the viscosity of the plastic melt solution supplied to the depolymerization reactor (3) below the viscosity of the plastic melt.

Patent Document 2 discloses a method for cracking and treating a hydrocarbon polymer in a fluid catalytic cracking (FCC) unit, characterized in that a mixture of the hydrocarbon polymer and a hydrocarbon oil selected from FCC gasoline, light cracked gas oil, heavy cracked gas oil, cracked residual oil, atmospheric residual oil, and desulfurized residual oil is mixed with FCC feedstock oil and supplied to the FCC unit.

JP 2014-518906 A JP 2002-294251 A

Patent Document 1 describes that the viscosity of a plastic melt solution is reduced by adding a solvent to the plastic melt. However, since a plastic melt solution to which a solvent has simply been added is prone to separation, the method described in Patent Document 1 may result in a plastic melt solution that is insufficiently mixed being supplied to a depolymerization reactor. As a result, the decomposability of the plastic material may not be sufficiently improved.
Incidentally, Patent Document 1 discloses a method for mixing plastic materials in which molten plastic is continuously discharged from a depolymerization reactor by a pump and recirculated back to the depolymerization reactor. However, since this method recirculates the molten plastic to be decomposed, it is considered difficult to improve the decomposition ability of the plastic materials relative to the molten plastic supplied to the depolymerization reactor.
Patent Document 2 discloses a method for cracking a mixture of a hydrocarbon polymer and a hydrocarbon oil using an FCC unit capable of cracking high boiling fractions in crude oil into high added value gasoline and the like by catalytic reaction, but Patent Document 2 does not pay any attention to the solubility of the hydrocarbon polymer in the hydrocarbon oil, specifically, the mixability of the hydrocarbon polymer and the hydrocarbon oil. Therefore, even in the method described in Patent Document 2, the mixture in a state of insufficient mixability may be mixed with FCC feedstock oil and supplied to the FCC unit. As a result, the decomposition ability of the hydrocarbon polymer may not be sufficiently improved.

The present invention aims to provide a waste plastic processing system that can improve the decomposition of waste plastic in a system that processes waste plastic using a decomposition processing device.

According to one aspect of the present invention, there is provided a waste plastic processing system for processing waste plastic, comprising:
A melting device for preparing molten waste plastic by melting the waste plastic;
A mixer for mixing the molten waste plastic with a raw material oil to prepare a mixture for decomposition treatment;
A molten waste plastic supply line that connects the melting device and the mixing device and supplies at least the molten waste plastic from the melting device to the mixing device;
A cracking treatment device that cracks both the molten waste plastics and the raw oil in the mixture for cracking treatment;
a first transportation line connected to the cracking treatment unit and configured to transport the feedstock oil to the cracking treatment unit;
At least one of a first branch line that connects the first transport line and the melting device and supplies the raw oil from the first transport line to the melting device, a second branch line that connects the first transport line and the molten waste plastic supply line and supplies the raw oil from the first transport line to the molten waste plastic supply line, and a third branch line that connects the first transport line and the mixing device and supplies the raw oil from the first transport line to the mixing device;
a second transport line that transports the mixture for decomposition treatment from the mixing device to at least one of the first transport line and the decomposition treatment device;
A waste plastic supply control means for controlling the amount of the waste plastic supplied to the melting device;
A waste plastic processing system is provided, comprising: a raw oil supply control means for controlling the supply amount of the raw oil supplied from at least one of the first branch line, the second branch line, and the third branch line; and a raw oil temperature control means for controlling the temperature of the raw oil transported through the first transport line.

In one embodiment of the waste plastic processing system according to the present invention, the waste plastic processing system further includes one or more additional feedstock oil supply lines for supplying at least one additional feedstock oil selected from the group consisting of the raw material oil, light hydrocarbon oil, naphtha, diesel, and heavy hydrocarbon oil different from the raw material oil, and the additional feedstock oil supply line is different from the first transport line,
The additional raw oil supply line is preferably connected to at least one of the melting device, the mixing device, the first branch line, the second branch line, the third branch line, the molten waste plastic supply line, and the second transport line.

In a waste plastic processing system according to one aspect of the present invention, it is preferable that the waste plastic supply control means controls the amount of the molten waste plastic melted by controlling the amount of the waste plastic supplied to the melting device.

In the waste plastic processing system according to one embodiment of the present invention, the feedstock oil is preferably at least one selected from the group consisting of heavy cracked gas oil, cracked residual oil, atmospheric residual oil, desulfurized residual oil, desulfurized vacuum gas oil, undesulfurized vacuum gas oil, undesulfurized atmospheric residual oil, and mineral oil.

In one embodiment of the waste plastic processing system of the present invention, the feedstock oil is preferably at least one selected from the group consisting of desulfurized vacuum diesel, heavy cracked diesel, desulfurized residual oil, and mineral oil.

In one aspect of the present invention, the waste plastic processing system preferably has at least the second branch line.

In one aspect of the present invention, the waste plastic processing system preferably has at least the first branch line and the third branch line.

In one aspect of the present invention, the waste plastic processing system further includes a first storage tank between the melting device and the mixing device,
It is preferable that the first storage tank stores at least a mixture of the molten waste plastic and the raw oil supplied from at least one of the first branch line and the second branch line.

In one aspect of the present invention, the waste plastic processing system further includes a second storage tank between the mixing device and the decomposition processing device,
It is preferable that the second storage tank stores at least the decomposition treatment mixture transported from the second transport line.

In one embodiment of the waste plastic processing system of the present invention, it is preferable that at least one of the first storage tank and the second storage tank is equipped with a gas venting means.

In the waste plastic processing system according to one aspect of the present invention, the waste plastic preferably includes at least one of polyethylene-derived waste plastic and polypropylene-derived waste plastic.

In one aspect of the present invention, the waste plastic processing system preferably includes multiple melting devices.

In one aspect of the waste plastic processing system of the present invention, the melting device is preferably a kneader.

In one aspect of the present invention, the waste plastic processing system preferably includes a plurality of the mixing devices.

In one embodiment of the waste plastic processing system of the present invention, it is preferable that the multiple mixing devices are arranged in parallel or in series.

In one aspect of the waste plastic processing system of the present invention, the mixing device is preferably a line mixer.

In one embodiment of the waste plastic processing system of the present invention, the decomposition processing device is preferably a fluid catalytic cracking device.

In one aspect of the present invention, a waste plastic processing system includes:
The waste plastic supply control means controls the supply amount of the waste plastic so that the ratio of the melted amount of the molten waste plastic in the decomposition treatment mixture to the total supply amount of the raw material oil (the total supply amount of the raw material oil / the melted amount of the molten waste plastic) is within a predetermined range in mass ratio;
It is preferable that the raw oil supply control means controls the supply amount of the raw oil so that the ratio of the total supply amount of the raw oil to the melted amount of the molten waste plastic in the decomposition treatment mixture (total supply amount of the raw oil/melted amount of the molten waste plastic) is within a predetermined range in terms of mass ratio.

According to one aspect of the present invention, a waste plastic processing system that can improve the decomposition of waste plastics in a system that processes waste plastics using a decomposition processing device can be provided.

1 is a schematic diagram of a waste plastic processing system according to a first embodiment. FIG. 11 is a schematic diagram of a waste plastic processing system according to a second embodiment. FIG. 11 is a schematic diagram of a waste plastic processing system according to a third embodiment. FIG. 11 is a schematic diagram of a waste plastic processing system according to a fourth embodiment. FIG. 13 is a schematic diagram of a waste plastic processing system according to a fifth embodiment. FIG. 13 is a schematic diagram of a waste plastic processing system according to a sixth embodiment.

In this specification, a numerical range expressed using "~" means a range that includes the number written before "~" as the lower limit and the number written after "~" as the upper limit.

First Embodiment
The waste plastic processing system according to this embodiment (hereinafter also simply referred to as the "processing system") is a system that processes waste plastic using a decomposition processing device used in the field of oil refining.
The inventors have discovered that by supplying raw oil to molten waste plastics (hereinafter also referred to as "molten waste plastics") from a branch line installed on the line that transports the raw oil, and mixing the molten waste plastics and raw oil in a mixing device, the molten waste plastics dissolve nearly uniformly in the raw oil, i.e., a mixture of molten waste plastics and raw oil with improved mixability (in this embodiment, referred to as a "mixture for decomposition processing") can be obtained.
In addition, in the treatment system of this embodiment, when supplying raw oil to the molten waste plastic, the mass ratio of the molten waste plastic and raw oil can be adjusted to adjust the kinetic viscosity of the decomposition treatment mixture within a predetermined range.
In the treatment system of this embodiment, the mixture for decomposition treatment is supplied to a decomposition treatment device directly or together with a raw material oil, and the waste plastics in the mixture for decomposition treatment are decomposed.
According to the processing system of this embodiment, the mixability of the molten waste plastic and the raw oil is improved, and the decomposition processing mixture with its kinetic viscosity adjusted to a predetermined range is decomposed in the decomposition processing device, thereby improving the decomposition ability of the waste plastic.
In addition, according to the treatment system of this embodiment, the decomposition treatment mixture, the kinetic viscosity of which has been adjusted to a predetermined range, is supplied to the decomposition treatment device, improving the transportability of the decomposition treatment mixture and reducing the load on transportation means such as pumps.

A processing system according to a first embodiment will be described with reference to the drawings.
In the first embodiment, a waste plastic processing system will be described as an example, which is equipped with a kneader as a melting device, a line mixer as a mixing device, a residual oil fluid catalytic cracking unit (RFCC unit) (one aspect of an FCC unit) as a cracking processing device, and a heat exchanger as a raw oil temperature control means.
In the following description, the ordinal expressions such as "first", "second" and "third" are intended to distinguish components and do not indicate an order.

<Overall composition>
FIG. 1 is a schematic diagram of a waste plastic processing system according to the first embodiment.
The processing system 100 shown in FIG. 1 includes a kneader 20 that prepares molten waste plastics by melting waste plastics, a line mixer 30 that prepares a mixture for decomposition processing by mixing the molten waste plastics prepared by the kneader 20 with raw oil, an RFCC device 50 that decomposes both the molten waste plastics and the raw oil in the mixture for decomposition processing prepared by the line mixer 30, and a second storage tank 40 provided between the line mixer 30 and the RFCC device 50.
The treatment system 100 also includes a first transport line 10 connected to the RFCC device 50 and transporting raw oil to the RFCC device 50, a molten waste plastic supply line 15 connecting the kneader 20 and the line mixer 30 and supplying at least molten waste plastic from the kneader 20 to the line mixer 30, a second branch line 12 connecting the first transport line 10 and the molten waste plastic supply line 15 and supplying raw oil from the first transport line 10 to the molten waste plastic supply line 15, and a second transport line 14 transporting the decomposition treatment mixture prepared in the line mixer 30 from the line mixer 30 to the first transport line 10. In this embodiment, the decomposition treatment mixture is stored in the second storage tank 40 and then transported to the first transport line 10 via the second transport line 14 by the centrifugal pump 41.
The processing system 100 also includes a waste plastic supply control means 25 that controls the amount of waste plastic supplied to the kneader 20, a second raw oil supply control means 121 that controls the amount of raw oil supplied from the second branch line 12 to the molten waste plastic supply line 15, and a heat exchanger HE (an example of a raw oil temperature control means) that controls the temperature of the raw oil.

<Kneader 20>
The kneader 20 prepares (obtains) molten waste plastics by melting the waste plastics.
In this specification, molten waste plastic means solid waste plastic that has been melted and liquefied. Therefore, the only difference between molten waste plastic and solid waste plastic is the state of the material.
The kneader 20 is connected to a waste plastic supply control means 25 for controlling the amount of waste plastic supplied.
The waste plastic supply control means 25 has a feeder 21 as a waste plastic supply means, and a feeder controller 24 that controls the operation of the feeder 21. The waste plastic supply control means 25 controls the amount of waste plastic supplied by transmitting a control signal from the feeder controller 24 to the feeder 21 and controlling the operation of the feeder 21. The feeder controller 24 can use a microcomputer or the like.
In this specification, the supply amount of waste plastic means the amount (mass) of waste plastic supplied per unit time.
Further, the kneader 20 is connected to a feeder 21 and a hopper 22 via a waste plastic supply line 23. The hopper 22 has a supply port (not shown) at a lower portion, and is capable of supplying waste plastic to the feeder 21 from the supply port.
The kneader 20 of this embodiment prepares (obtains) molten waste plastics by melting and kneading the waste plastics supplied from the hopper 22 via the feeder 21 at a predetermined temperature.

The waste plastic supply control means 25 may control the amount of melted molten waste plastic by controlling the amount of waste plastic supplied from the feeder 21 to the kneader 20. The amount of melted molten waste plastic is calculated from the amount of waste plastic supplied to the kneader 20. In this case, the waste plastic supply control means 25 controls the amount of melted molten waste plastic by transmitting a control signal from the feeder controller 24 to the feeder 21 and controlling the operation of the feeder 21.
In this specification, the melting amount of the molten waste plastic means the amount (mass) of the waste plastic melted per unit time. The melting amount of the molten waste plastic is calculated from the supply amount of the waste plastic.

The kneading machine 20 is not particularly limited, but examples thereof include an extruder (for example, a single-screw extruder or a multi-screw extruder), a kneader, and a mixer.
The melting temperature of the waste plastic is, for example, 175° C. or higher and 260° C. or lower. The melting temperature of the waste plastic is the set temperature of the kneader 20.

<First transportation line 10>
The first transportation line 10 is connected to the RFCC unit 50 and transports the raw oil to the RFCC unit 50. The first transportation line 10 of this embodiment has a branch point B1 at the upstream side where it branches into the second branch line 12, and a junction point C1 at the downstream side where it merges with the second transportation line 14.
The raw oil in the first transport line 10 is preferably heated to, for example, 80° C. or more and 240° C. or less, and more preferably heated to 160° C. or more and 230° C. or less. The temperature of the raw oil in the first transport line 10 can be controlled, for example, by a temperature control means (e.g., a heat exchanger, a heater, etc.) installed at any position in the first transport line 10.

<Molten waste plastic supply line 15>
The molten waste plastic supply line 15 connects the kneader 20 and the line mixer 30 and supplies at least the molten waste plastic from the kneader 20 to the line mixer 30 .
In this embodiment, the molten waste plastic supply line 15 merges (mixes) the molten waste plastic prepared in the kneader 20 with the raw oil transported from the second branch line 12 at the junction C2 to produce molten waste plastic mixed oil (a mixture of molten waste plastic and raw oil), and supplies the molten waste plastic mixed oil to the line mixer 30.
The temperature of the molten waste plastic supply line 15 is preferably raised to a temperature at which the molten state of the molten waste plastic discharged from the kneader 20 can be maintained.
The temperature of the molten waste plastic supply line 15 is, for example, 160° C. or higher and 260° C. or lower. The temperature of the molten waste plastic supply line 15 can be controlled, for example, by a temperature control means (for example, a heat exchanger, a heater, etc.) installed at any position of the molten waste plastic supply line 15.

<Second branch line 12>
The second branch line 12 connects the first transportation line 10 and the molten waste plastic supply line 15, and supplies raw oil from the first transportation line 10 to the molten waste plastic supply line 15. The second branch line 12 in this embodiment branches off from the branch point B1 of the first transportation line 10, and supplies raw oil to the junction C2 with the molten waste plastic supply line 15.
A second feedstock oil supply control means 121 is provided in the second branch line 12 to control the amount of feedstock oil supplied to the junction C2.
The second feedstock oil supply control means 121 has a second adjustment valve 122 as a feedstock oil supply means, and a second controller 123 .
The second feedstock oil supply control means 121 controls the amount of feedstock oil supplied by transmitting a control signal from the second controller 123 to the second control valve 122 and controlling the operation of the second control valve 122. The second controller 123 can be a microcomputer or the like.
In this specification, the feedstock oil supply amount means the amount (mass) supplied per unit time.

From the viewpoint of mixing the raw oil and the molten waste plastic well, the raw oil in the second branch line 12 is preferably heated to, for example, 80° C. or more and 240° C. or less, and more preferably heated to 160° C. or more and 230° C. or less. The temperature of the raw oil in the second branch line 12 can be controlled, for example, by a temperature control means (e.g., a heat exchanger, a heater, etc.) installed at any position in the second branch line 12. The temperature of the raw oil is the set temperature of the temperature control means.
In the case of FIG. 1 , the temperature of the feed oil in the second branch line 12 is controlled by a heat exchanger HE disposed midway along the second branch line 12 .
The number and installation locations of the heat exchangers HE are not particularly limited. For example, a plurality of heat exchangers HE may be provided in the first transport line 10 and the second branch line 12 to heat the feed oil in stages.

<Line mixer 30>
The line mixer 30 mixes the molten waste plastic prepared in the kneader 20 with the raw oil to prepare (obtain) a mixture for decomposition treatment.
The line mixer 30 of this embodiment prepares a mixture for cracking treatment by mixing the molten waste plastic prepared in the kneader 20 and transported via the molten waste plastic supply line 15 with the raw oil transported from the second branch line 12.
The kinematic viscosity of the prepared mixture for decomposition treatment is preferably adjusted to a predetermined range from the viewpoint of improving the decomposition property of the waste plastics. The predetermined range will be described later.
The line mixer 30 has a stirring means (for example, a rotor or the like).
The line mixer 30 is not particularly limited, and an in-line mixer (for example, a static mixer) can be used. The line mixer 30 may be a continuous mixer.
The mixing temperature is set by the temperature of the molten waste plastic supply line 15 and the temperature of the raw oil in each branch line (in this embodiment, the temperature of the raw oil in the second branch line 12). Therefore, the mixing temperature should be approximately the same as the temperature of the molten waste plastic supply line 15 and the temperature of the raw oil in each branch line, for example, 160°C or higher and 260°C or lower.
The mixing temperature does not need to be controlled, but may be controlled by a temperature control means (for example, a heat exchanger, a heater, etc.) installed at any position in the line mixer 30.

<Second storage tank 40>
The second storage tank 40 stores the decomposition treatment mixture prepared in the line mixer 30. A centrifugal pump 41 is connected to the second storage tank 40. The pump is preferably selected appropriately depending on the kinetic viscosity of the decomposition treatment mixture. For example, a gear pump may be used as the pump. The second storage tank 40 is preferably equipped with a pump as a means for supplying the decomposition treatment mixture, but the decomposition treatment mixture may be supplied to the second transport line 14 by its own pressure.
The second storage tank 40 preferably has a venting means for discharging gases (e.g., carbon dioxide gas, water vapor, volatile organic compounds, etc.) generated from the decomposition mixture. The venting means is not particularly limited, but may be, for example, a venting pipe.
By providing the second storage tank 40 with the gas venting means, foaming of the decomposition mixture can be prevented or reduced, and the decomposition mixture can be transported smoothly, which is expected to improve operability. As a result, it is believed that the decomposition efficiency of waste plastics can be improved.
In addition, the second storage tank 40 may have a stirring means (e.g., a rotor or the like) from the viewpoint of further improving the mixability of the decomposition treatment mixture.
The temperature of the second storage tank 40 is preferably heated to, for example, 160° C. or more and 240° C. or less from the viewpoint of maintaining the molten state of the molten waste plastic in the decomposition treatment mixture and maintaining the kinetic viscosity of the decomposition treatment mixture within a predetermined range. The second storage tank 40 is preferably equipped with a temperature detection means (e.g., a thermometer, etc.), and the temperature of the second storage tank 40 is preferably controlled by a temperature control means (e.g., a heat exchanger, a heater, etc.).

<RFCC device 50>
The RFCC device 50 decomposes both the molten waste plastics and the raw oil in the mixture for decomposition treatment prepared in the line mixer 30 .
The RFCC device 50 of this embodiment is configured so that the cracking treatment mixture transported via the second transport line 14 and the raw oil transported from the first transport line 10 to the RFCC device 50 are joined (mixed) at the junction C1 (downstream of the second branch line 12) and the cracking treatment mixture and the raw oil are supplied together.
The RFCC unit 50 is one embodiment of a fluid catalytic cracking unit (FCC unit).
The RFCC unit 50 and the FCC unit may be units commonly used in the field of petroleum refining, and basically consist of a reaction tower, a catalyst/product oil separator, a section for removing oil from the catalyst surface, and a catalyst regeneration tower, with the catalyst circulating within this system.
The catalyst used is usually a catalyst containing synthetic zeolite, and the process may be any process developed by UOP, IFP, or the like.
The catalysts and operating conditions used in the RFCC unit 50 and the FCC unit are not particularly limited and can be set appropriately.

<Second transport line 14>
The second transport line 14 transports the decomposition treatment mixture prepared in the line mixer 30 from the line mixer 30 to the first transport line 10.
In this embodiment, the second transport line 14 transports the decomposition treatment mixture prepared in the line mixer 30 and stored in the second storage tank 40 to the junction C1 with the first transport line 10 using a centrifugal pump 41.
From the viewpoint of transporting the mixture for decomposition treatment while maintaining the kinetic viscosity of the mixture for decomposition treatment within a predetermined range, the temperature of the second transport line 14 is preferably heated to, for example, 160° C. or more and 240° C. or less. The temperature of the second transport line 14 can be controlled by a temperature control means (e.g., a heat exchanger, a heater, etc.) installed at any position of the second transport line 14.

<Action>
In the treatment system 100 of the first embodiment, waste plastics are decomposed together with raw oil in the following manner.
First, waste plastic is supplied to the kneader 20 by the feeder 21. The waste plastic is melted at a predetermined temperature in the kneader 20 to become molten waste plastic. The molten waste plastic is discharged from the kneader 20 in a molten state, a dissolved state, or as a slurry. The molten waste plastic discharged from the kneader 20 is transported through the molten waste plastic supply line 15, and is merged (mixed) with the raw material oil transported from the second branch line 12 at the junction C2 to become a molten waste plastic mixed oil, which is supplied to the line mixer 30.
In the line mixer 30, the molten waste plastic mixed oil (a mixture of molten waste plastic and raw oil) is further mixed to prepare a mixture for cracking treatment. The kinetic viscosity of this mixture for cracking treatment is adjusted to a predetermined range, as will be described in detail later.
The mixture for cracking treatment prepared in the line mixer 30 is supplied to and stored in the second storage tank 40 via the second transport line 14. The mixture for cracking treatment is then transported by a centrifugal pump 41 to the junction C1 via the second transport line 14, where it is merged (mixed) with the feed oil transported from the first transport line 10 to the RFCC unit 50 and supplied to the RFCC unit 50.
In the RFCC device 50, under specified conditions, the molten waste plastics contained in the mixture for decomposition treatment are decomposed into liquefied petroleum gases (propane, propylene, n-butane, isobutane, butylene, etc.), and the raw oil is decomposed into FG (gasoline), LCO (light cracked diesel oil), CLO (residual oil), etc.

＜Effects＞
In the first embodiment of the processing system 100, at the confluence C2, the molten waste plastic prepared in the kneader 20 and the raw oil transported from the second branch line 12 are mixed to form a molten waste plastic mixed oil (first mixing), and then in the subsequent line mixer 30, the molten waste plastic mixed oil is further mixed to prepare a mixture for decomposition processing (second mixing).
Also at the junction C1, the mixture for cracking treatment is mixed with the feed oil being transported from the first transport line 10 to the RFCC unit 50 (third mixing).
In this manner, in the treatment system 100 of the first embodiment, the raw material oil is supplied to the molten waste plastic in multiple stages, so that the mixture for decomposition treatment supplied to the RFCC device 50 is a mixture with improved mixability.
In addition, by controlling the amount of waste plastic supplied to the kneader 20 using the waste plastic supply control means 25 and controlling the amount of raw oil supplied from the second branch line 12 using the second raw oil supply control means 121, the kinetic viscosity of the cracking treatment mixture prepared in the line mixer 30 can be adjusted to a predetermined range.
Therefore, according to the treatment system 100 of the first embodiment, the mixability of the molten waste plastics and the raw oil is improved, and the mixture for decomposition treatment with a controlled kinetic viscosity is decomposed in the RFCC device 50, so that the decompositionability of the waste plastics can be improved. Also, the decompositionability of the raw oil can be improved.

Second Embodiment
The second embodiment will be described focusing on the differences from the first embodiment, and the description of similar items will be omitted or simplified by using the same reference numerals, for example.

<Overall composition>
FIG. 2 is a schematic diagram of a waste plastic processing system according to the second embodiment.
The processing system 200 shown in FIG. 2 includes a kneader 20, a line mixer 30, an RFCC device 50, a first transport line 10, a molten waste plastic supply line 15, a first branch line 11, a third branch line 13, a second transport line 14, a first storage tank 60, and a second storage tank 40.
The processing system 200 also includes a waste plastic supply control means 25, a first raw material oil supply control means 111 for controlling the amount of raw material oil supplied from the first branch line 11 to the kneader 20, a third raw material oil supply control means 131 for controlling the amount of raw material oil supplied from the third branch line 13 to the line mixer 30, and a heat exchanger HE for controlling the temperature of the raw material oil.
That is, the treatment system 200 of the second embodiment differs from the first embodiment in that it includes the first branch line 11, the third branch line 13, and the first storage tank 60, but does not include the second branch line 12. The other points are the same as those of the first embodiment.

<First storage tank 60>
The first storage tank 60 stores a mixture of the molten waste plastic prepared by the kneader 20 and the raw oil supplied to the kneader 20 from the first branch line 11 (hereinafter, also referred to as "molten waste plastic mixed oil A"). A gear pump 61 is connected to the first storage tank 60. The first storage tank 60 is preferably equipped with a pump as a means for supplying the molten waste plastic mixed oil A, but the molten waste plastic mixed oil A may be supplied to the molten waste plastic supply line 15 by its own pressure.
The first storage tank 60 preferably has a degassing means for discharging gas (e.g., carbon dioxide, water vapor, volatile organic compounds, etc.) generated from the molten waste plastic mixed oil A. The degassing means is not particularly limited, but may be, for example, a degassing pipe.
By providing the first storage tank 60 with a gas venting means, foaming of the molten waste plastic mixed oil A can be prevented or reduced, and the molten waste plastic mixed oil A can be smoothly transferred, which is expected to improve operability. As a result, it is believed that the decomposition efficiency of waste plastics can be improved.
In addition, the first storage tank 60 may have a stirring means (e.g., a rotor, etc.) in order to further improve the mixability of the molten waste plastic mixed oil A.
The temperature of the first storage tank 60 is preferably heated to, for example, 160° C. or more and 260° C. or less from the viewpoint of maintaining the molten state of the molten waste plastic in the molten waste plastic mixed oil A. The first storage tank 60 is preferably equipped with a temperature detection means (e.g., a thermometer, etc.), and the temperature of the first storage tank 60 is preferably controlled by a temperature control means (e.g., a heat exchanger, a heater, etc.).

<First branch line 11>
The first branch line 11 connects the first transportation line 10 and the kneader 20 and supplies the raw oil from the first transportation line 10 to the kneader 20 .
The first branch line 11 in this embodiment branches off from a branch point B<b>1 of the first transportation line 10 , and further branches off at a branch point B<b>2 to supply the raw material oil to the outlet side of the kneader 20 .
A first raw material oil supply control means 111 for controlling the amount of raw material oil supplied to the kneader 20 is provided in the first branch line 11 .
The first feedstock oil supply control means 111 has a first adjustment valve 112 as a feedstock oil supply means, and a first controller 113 .
The first feedstock oil supply control means 111 controls the amount of feedstock oil supplied by transmitting a control signal from the first controller 113 to the first control valve 112 and controlling the operation of the first control valve 112. The first controller 113 can be a microcomputer or the like.
The temperature of the raw oil in the first branch line 11 is preferably heated to a temperature at which the raw oil and the molten waste plastics can be mixed while maintaining the molten state of the molten waste plastics.
The raw oil in the first branch line 11 is heated, for example, to 80° C. or more and 240° C. or less, preferably 160° C. or more and 230° C. or less, by a branch line temperature control means (not shown, for example, a heat exchanger and a heater). The temperature of the raw oil is the set temperature of the branch line temperature control means. In the case of FIG. 2, the temperature of the raw oil in the first branch line 11 is controlled by a heat exchanger HE arranged between the branch point B1 and the branch point B2. The number and installation locations of the branch line temperature control means are not particularly limited.

<Third branch line 13>
The third branch line 13 connects the first transportation line 10 and the line mixer 30 and supplies the raw oil from the first transportation line 10 to the line mixer 30 .
The third branch line 13 in this embodiment branches off from the branch point B1 of the first transportation line 10, and further branches off at a branch point B2 to supply the raw oil to the line mixer 30.
A third feedstock oil supply control means 131 for controlling the amount of feedstock oil supplied is provided in the third branch line 13 .
The third feedstock oil supply control means 131 has a third adjustment valve 132 as a feedstock oil supply means, and a third controller 133 .
The third feedstock oil supply control means 131 controls the amount of feedstock oil supplied by transmitting a control signal from the third controller 133 to the third adjustment valve 132 and controlling the operation of the third adjustment valve 132. The third adjustment valve 132 can use a microcomputer or the like.
It is preferable that the temperature of the raw oil in the third branch line 13 is heated to a temperature at which the raw oil and the molten waste plastic mixed oil A can be mixed in the line mixer 30 while maintaining the molten state of the molten waste plastic mixed oil A.
The raw oil in the third branch line 13 is heated, for example, to 80° C. or more and 240° C. or less, preferably 160° C. or more and 230° C. or less, by a branch line temperature control means (not shown, for example, a heat exchanger and a heater). The temperature of the raw oil is the set temperature of the branch line temperature control means. In the case of FIG. 2, the temperature of the raw oil in the third branch line 13 is controlled by a heat exchanger HE arranged between the branch point B1 and the branch point B2. The number and installation locations of the branch line temperature control means are not particularly limited.

<Action>
In the treatment system 200 of the second embodiment, waste plastics are decomposed together with raw oil in the following manner.
First, waste plastic is supplied to the kneader 20 by the feeder 21. The waste plastic is melted at a predetermined temperature in the kneader 20 to become molten waste plastic.
In addition, raw material oil transported from the first branch line 11 is supplied to the outlet side of the kneader 20 and mixed with the molten waste plastic to prepare the molten waste plastic mixed oil A (a mixture of molten waste plastic and raw material oil).
The molten waste plastic mixed oil A is discharged from the kneader 20 and stored in the first storage tank 60 , and then transported by the gear pump 61 through the molten waste plastic supply line 15 and supplied to the line mixer 30 .
The line mixer 30 is supplied with the raw oil transported from the third branch line 13. In the line mixer 30, the molten waste plastic mixed oil A and the raw oil supplied from the third branch line 13 are mixed to prepare a mixture for cracking treatment. The mixture for cracking treatment has a kinetic viscosity adjusted to a predetermined range, as in the first embodiment.
The mixture for decomposition treatment prepared in the line mixer 30 is stored in the second storage tank 40 as in the first embodiment, and then supplied to the RFCC device 50. In the RFCC device 50, the molten waste plastic is decomposed together with the raw material oil as in the first embodiment.

＜Effects＞
In the second embodiment of the treatment system 200, the molten waste plastics are mixed with the raw oil transported from the first branch line 11 in the kneader 20 to prepare the molten waste plastic mixed oil A (a mixture of molten waste plastics and raw oil) (first mixing), and in the line mixer 30, the molten waste plastic mixed oil A is mixed with the raw oil supplied from the third branch line 13 to prepare a mixture for cracking (second mixing).
Also at the junction C1, the mixture for cracking treatment is mixed with the feed oil being transported from the first transport line 10 to the RFCC unit 50 (third mixing).
In this way, in the second embodiment of the treatment system 200, as in the first embodiment, raw oil is supplied to the molten waste plastic in multiple stages, so that the mixture for decomposition treatment supplied to the RFCC device 50 has improved mixability.
In addition, the kinetic viscosity of the mixture for cracking treatment can be adjusted within a predetermined range by controlling the amount of waste plastic supplied to the kneader 20 using the waste plastic supply control means 25, controlling the amount of raw oil supplied from the first branch line 11 using the first raw oil supply control means 111, and controlling the amount of raw oil supplied from the third branch line 13 using the third raw oil supply control means 131.
Therefore, according to the second embodiment of the treatment system 200, the mixability of the molten waste plastic and the raw oil is improved, and the decomposition treatment mixture with controlled kinetic viscosity is decomposed in the RFCC device 50, thereby improving the decompositionability of the waste plastic and also improving the decompositionability of the raw oil.
In particular, in the treatment system 200 of the second embodiment, the molten waste plastic mixed oil A stored in the first storage tank 60 is supplied to the line mixer 30 from the molten waste plastic supply line 15 by the gear pump 61, so that the fluctuation range of the viscosity of the decomposition treatment mixture in the line mixer can be reduced, and it becomes easier to obtain a decomposition treatment mixture with an adjusted kinetic viscosity. As a result, the decomposition treatment mixture can be transported stably and smoothly to the RFCC device 50, and the waste plastic can be decomposed efficiently.

Third Embodiment
The third embodiment will be described focusing on the differences from the first and second embodiments, and the description of similar items will be omitted or simplified by using the same reference numerals, for example.

<Overall composition>
FIG. 3 is a schematic diagram of a waste plastic processing system according to the third embodiment.
3 differs from the second embodiment in that it includes a second branch line 12 and gas vent lines 43 and 44. The other points are the same as those of the second embodiment.

<Second branch line 12>
The second branch line 12 of the third embodiment branches off from the branch point B1 of the first transportation line 10, and further branches off at branch points B2 and B3 to supply raw oil to the junction C3 with the molten waste plastic supply line 15.
A second feed oil supply control means 121 for controlling the amount of feed oil supplied is provided in the second branch line 12 .
The configuration of the second feed oil supply control means 121 is similar to that of the first embodiment.
The temperature of the feed oil in the second branch line 12 is also heated by the heat exchanger HE to, for example, 80° C. or more and 240° C. or less, preferably 160° C. or more and 230° C. or less, as in the first embodiment.

<Gas vent lines 43, 44>
A first degassing line 44 is provided as a degassing means at an upper portion of the first storage tank 60. Similarly, a second degassing line 43 is provided as a degassing means at an upper portion of the second storage tank 40.
In the third embodiment, the first gas vent line 44 is connected to the second gas vent line 43. The gas generated in the first storage tank 60 flows through the first gas vent line 44 to the second gas vent line 43, and is discharged to the outside from the second gas vent line 43 together with the gas generated in the second storage tank 40.
The gas venting means is not limited to the gas venting line, and gas may be discharged (vented) from each of the first storage tank 60 and the second storage tank 40 to the outside via a gas venting means.

<Action>
In the treatment system 300 of the third embodiment, waste plastics are decomposed together with raw oil in the following manner.
In the same manner as in the second embodiment, the molten waste plastic mixed oil A (a mixture of molten waste plastic and raw material oil) is prepared at the outlet side of the kneader 20 .
The molten waste plastic mixed oil A (a mixture of molten waste plastic and raw oil) discharged from the kneader 20 is mixed with the raw oil transported from the second branch line 12 at the junction C3 on the molten waste plastic supply line 15 to become a mixture of molten waste plastic mixed oil A and raw oil (hereinafter also referred to as "molten waste plastic mixed oil B"), which is stored in the first storage tank 60. The process thereafter is the same as in the second embodiment.

＜Effects＞
In the third embodiment of the treatment system 300, compared to the second embodiment, the molten waste plastic mixed oil A is mixed with raw oil transported from the second branch line 12 at the junction C3 midway along the molten waste plastic supply line 15.
Therefore, in the third embodiment of the treatment system 300, raw material oil is supplied to the molten waste plastic in multiple stages, so that the mixture for decomposition treatment prepared in the line mixer 30 and supplied to the RFCC device 50 becomes a mixture with improved mixability.
Therefore, according to the treatment system 300 of the third embodiment, the mixability of the molten waste plastics and the raw oil is improved, and the mixture for decomposition treatment with a controlled kinetic viscosity is decomposed in the RFCC device 50, so that the decompositionability of the waste plastics can be improved. Also, the decompositionability of the raw oil can be improved.
In particular, in the treatment system 300 of the third embodiment, the raw oil is further supplied to the first storage tank 60 from the second branch line 12, so that when the mixture (the molten waste plastic mixed oil B) stored in the first storage tank is transported from the molten waste plastic supply line 15 to the line mixer 30 by the gear pump 61, the viscosity and the fluctuation range of the mixture can be reduced, and the mixture can be transported stably and smoothly to the line mixer 30. As a result, it becomes easier to obtain a mixture for decomposition treatment with an adjusted kinetic viscosity.

Fourth Embodiment
The fourth embodiment will be described focusing on the differences from the first to third embodiments, and the description of similar items will be omitted or simplified by using the same reference numerals, for example.

<Overall composition>
FIG. 4 is a schematic diagram of a waste plastic processing system according to the fourth embodiment.
4 differs from the processing system 300 of the third embodiment in that it includes two line mixers. The other points are the same as those of the third embodiment.

<Line mixers 30, 30B>
The processing system 300A of the fourth embodiment includes two line mixers 30 and 30B. The two line mixers 30 and 30B are arranged in parallel.

<Molten waste plastic supply line 15>
The molten waste plastic supply line 15 of the fourth embodiment connects the kneader 20, the first storage tank 60, the line mixer 30 and the line mixer 30B.
In the case of FIG. 4 , the molten waste plastic supply line 15 is branched into a first mixed oil branch line 151 and a second mixed oil branch line 152 at a branch point B5 downstream of the first storage tank 60 .
The first mixed oil branch line 151 is connected to the line mixer 30. The second mixed oil branch line 152 is connected to the line mixer 30B.

<Third branch line 13>
The third branch line 13 of the fourth embodiment connects the first transport line 10 and the line mixer 30, and connects the first transport line 10 and the line mixer 30B, respectively.
In the case of Fig. 4, the third branch line 13 passes through branch points B2 and B3 from a branch point B1 of the first transportation line 10, and then branches into a first branch line 13A and a second branch line 13B at a branch point B4. The first branch line 13A is connected to a line mixer 30. The second branch line 13B is connected to a line mixer 30B.
A third feed oil supply control means 131 similar to that in the second embodiment is provided in the first branch line 13A.
A fourth feedstock supply control means for controlling the amount of feedstock oil supplied to the line mixer 30B is also provided in the middle of the second branch line 13B, but the fourth feedstock supply control means is not shown. The fourth feedstock supply control means may have the same configuration and operating conditions as the third feedstock supply control means 131, or may have different configurations and operating conditions.

<Action>
In the treatment system 300A of the fourth embodiment, waste plastics are decomposed together with raw oil in the following manner.
In a manner similar to the third embodiment, the molten waste plastic mixed oil B stored in the first storage tank 60 is transported through the molten waste plastic supply line 15 by a gear pump 61, and a portion of the molten waste plastic mixed oil B is supplied to the line mixer 30 from the branch point B5 via the first mixed oil branch line 151, and the remainder is supplied to the line mixer 30B from the branch point B5 via the second mixed oil branch line 152.
In the line mixer 30, the molten waste plastic mixed oil B and the raw oil supplied from the first branch line 13A are mixed to prepare a mixture for cracking treatment (hereinafter also referred to as "mixture for cracking treatment X1"). In the line mixer 30B, the molten waste plastic mixed oil B and the raw oil supplied from the second branch line 13B are mixed to prepare a mixture for cracking treatment (hereinafter also referred to as "mixture for cracking treatment Y1").
The decomposition treatment mixture X1 and the decomposition treatment mixture Y1 merge at the junction C4 of the second transport line 14, are stored in the second storage tank 40, and then are supplied to the RFCC device 50 in a manner similar to the third embodiment.

＜Effects＞
In the treatment system 300A of the fourth embodiment, compared to the third embodiment, two line mixers 30, 30B are arranged in parallel, and a mixture for decomposition treatment is prepared in each line mixer, thereby further improving the mixing state of the molten waste plastic and raw oil and increasing the amount of molten waste plastic for treatment, and making it possible to prepare a larger amount of mixture for decomposition treatment to be decomposed.
Therefore, according to the treatment system 300A of the fourth embodiment, the decomposition property of the waste plastic can be further improved, the decomposition property of the raw oil can be improved, and the amount of decomposed waste plastic can be increased.

Fifth Embodiment
The fifth embodiment will be described focusing on the differences from the first to fourth embodiments, and the description of similar items will be omitted or simplified by using the same reference numerals, for example.

FIG. 5 is a schematic diagram of a waste plastic processing system according to the fifth embodiment.
5 is different from the processing system 300A of the fourth embodiment in that the processing system 400 includes two kneaders, three line mixers, and does not include the second branch line 12. The other points are the same as those of the fourth embodiment.

<Kneader 20, 20A>
The processing system 400 of the fifth embodiment includes two mixers 20 and 20A. The two mixers 20 and 20A are arranged in parallel.
The kneader 20 mixes the molten waste plastic obtained by melting the waste plastic with raw oil supplied to the outlet side of the kneader 20 from the first branch line 11 to prepare molten waste plastic mixed oil A (a mixture of molten waste plastic and raw oil).
Although not shown in the figure, kneader 20A, like kneader 20, mixes molten waste plastic obtained by melting waste plastic with raw material oil supplied to the outlet side of kneader 20A from a supply line other than the first branch line 11 (e.g., an additional raw material oil supply line, etc.) to prepare molten waste plastic mixed oil A' (a mixture of molten waste plastic and raw material oil).
The amount of the raw oil supplied to the kneader 20A is preferably controlled by any raw oil supply control means.
The mixer 20A may have the same configuration and operating conditions as the mixer 20, or may have a different configuration and operating conditions.
5, the feeder, hopper, and waste plastic supply control means connected to the kneader 20A are not shown. The configurations of the feeder, hopper, and waste plastic supply control means are not particularly limited.

<Line mixers 30, 30A, 30B>
The processing system 400 of the fifth embodiment includes three line mixers. Two line mixers 30 and 30A are arranged in series, and the remaining line mixer 30B is arranged in parallel with the two line mixers 30 and 30A.
The line mixers 30A and 30B may have the same configuration and operating conditions as the line mixer 30, or may have different configurations and operating conditions from each other.

<Molten waste plastic supply line 15>
The molten waste plastic supply line 15 of the fifth embodiment connects the kneader 20, the kneader 20A, the first storage tank 60, the line mixer 30 and the line mixer 30B.

<Action>
In the treatment system 400 of the fifth embodiment, waste plastics are decomposed together with raw oil in the following manner.
First, waste plastics are supplied to two kneaders 20 and 20A in the same manner as in the first embodiment. In the kneader 20, a mixed oil A of molten waste plastics is prepared, and in the kneader 20A, a mixed oil A' of molten waste plastics is prepared.
The molten waste plastic mixed oil A and the molten waste plastic mixed oil A' are merged (mixed) at the junction C5 and stored in the first storage tank 60. The molten waste plastic mixed oil (a mixture of the molten waste plastic mixed oil A and the molten waste plastic mixed oil A') stored in the first storage tank 60 is transported through the molten waste plastic supply line 15 by the gear pump 61, and a portion of it is supplied to the line mixer 30 from the branch point B5 via the first mixed oil branch line 151, and the remainder is supplied to the line mixer 30B from the branch point B5 via the second mixed oil branch line 152.
In the line mixer 30, the molten waste plastic mixed oil supplied from the first mixed oil branch line 151 and the raw oil supplied from the first branch line 13A are mixed to prepare a mixture for cracking treatment. The mixture for cracking treatment is then transported through the second transport line 14 connected to the outlet of the line mixer 30 and supplied to the line mixer 30A. In the line mixer 30A, the mixture for cracking treatment is further mixed to prepare a mixture for cracking treatment (hereinafter also referred to as "mixture for cracking treatment X2").
Meanwhile, in the line mixer 30B, the molten waste plastic mixed oil supplied from the second mixed oil branch line 152 and the raw oil supplied from the second branch line 13B are mixed to prepare a mixture for cracking treatment (hereinafter also referred to as "mixture for cracking treatment Y2").
The kinetic viscosity at 160° C. of the decomposition treatment mixture X2 and the decomposition treatment mixture Y2 is adjusted to be within a predetermined range (preferably 1 mm ² /s or more and 60 mm ² /s or less).
After the decomposition treatment mixture X2 and the decomposition treatment mixture Y2 join at the joining point C4 of the second transport line 14, they are stored in the second storage tank 40, and then supplied to the RFCC device 50 in a manner similar to the fourth embodiment.
In the RFCC device 50, the molten waste plastics are decomposed together with the raw material oil, as in the fourth embodiment.

＜Effects＞
In the fifth embodiment, the processing system 400 is different from the fourth embodiment in that two kneaders 20 and 20A are arranged in parallel, and each kneader prepares the molten waste plastic mixed oil A and the molten waste plastic mixed oil A', so that more molten waste plastics to be decomposed can be prepared. Furthermore, the same or different operating conditions can be set in each kneader according to the type, composition, shape, and state of the waste plastics to be decomposed, so that the mixability of the molten waste plastic mixed oil A and the molten waste plastic mixed oil A' is improved.
In addition, in the treatment system 400 of the fifth embodiment, the mixture for decomposition treatment prepared in the line mixer 30 is further continuously mixed in the line mixer 30A, so that a "mixture for decomposition treatment X2" with improved mixability is prepared.
Therefore, according to the treatment system 400 of the fifth embodiment, the decomposition property of waste plastics can be further improved, the decomposition property of raw oil can be improved, and the amount of decomposed waste plastics can be increased.

[Fifth embodiment A]
The processing system of the fifth embodiment A differs from the processing system 400 (FIG. 5) described in the fifth embodiment in that a line mixer 30C is further provided in series downstream of the line mixer 30B. The other points are the same as those of the fifth embodiment.
The processing system of the fifth embodiment A is not shown in the drawings. The following description will be given by using the reference numerals in FIG.

<Line mixers 30, 30A, 30B, 30C>
The treatment system of the fifth embodiment A includes four line mixers. Two line mixers 30 and 30A are arranged in series, and the remaining two line mixers 30B and 30C are arranged in parallel to the two line mixers 30 and 30A.
The line mixer 30C may have the same configuration and operating conditions as the line mixers 30, 30A, and 30B, or may have different configurations and operating conditions.

<Action>
In the treatment system 400 of the fifth embodiment A, waste plastics are decomposed together with raw oil in the following manner.
In a manner similar to the fifth embodiment, the molten waste plastic mixed oil (a mixture of molten waste plastic mixed oil A and molten waste plastic mixed oil A') stored in the first storage tank 60 is transported through the molten waste plastic supply line 15 by a gear pump 61, and a portion of it is supplied to the line mixer 30 via the first mixed oil branch line 151 from the branch point B5, and the remainder is supplied to the line mixer 30B via the second mixed oil branch line 152 from the branch point B5.
In the line mixer 30B, a mixture for decomposition treatment Y2 is prepared. The mixture for decomposition treatment Y2 is transported through a second transport line 14 connected to the outlet of the line mixer 30B, and is supplied to the line mixer 30C. In the line mixer 30C, the mixture for decomposition treatment Y2 is further mixed to prepare a mixture for decomposition treatment (hereinafter also referred to as "mixture for decomposition treatment Y2'").
The kinetic viscosity of the decomposition treatment mixture Y2' at 160° C. is adjusted to be 1 mm ² /s or more and 60 mm ² /s or less.
The line mixer 30C may have the same configuration and operating conditions as the line mixers 30, 30A, and 30B, or may have different configurations and operating conditions.
The decomposition treatment mixture X2 and the decomposition treatment mixture Y2' are merged at the junction C4 of the second transport line 14, then stored in the second storage tank 40, and then supplied to the RFCC device 50 in a manner similar to the fifth embodiment.
In the RFCC device 50, the molten waste plastics are decomposed together with the raw material oil, as in the fifth embodiment.

＜Effects＞
In the treatment system of the fifth embodiment A, the mixture for decomposition treatment X2 and the mixture for decomposition treatment Y2' having improved mixability are prepared.
Therefore, according to the treatment system of the fifth embodiment A, the decomposition ability of waste plastics can be further improved, the decomposition ability of raw oil can be improved, and the amount of decomposed waste plastics can be further increased.

Sixth Embodiment
The sixth embodiment will be described focusing on the differences from the first to fifth embodiments and the fifth embodiment A, and the description of similar matters will be omitted or simplified by using the same reference symbols, for example.

FIG. 6 is a schematic diagram of a waste plastic processing system according to the sixth embodiment.
The treatment system 500 shown in Fig. 6 differs from the first embodiment in that it includes an additional feedstock supply line 70 for supplying another additional feedstock (hereinafter also referred to as "additional feedstock"). The other points are the same as those of the first embodiment.

<Additional Feedstock Oil Supply Line 70>
The additional feedstock oil supply line 70 in this embodiment supplies the additional feedstock oil to the outlet side of the kneader 20. The additional feedstock oil will be described later.
Additional raw material supply control means 171 for controlling the supply amount of additional raw material is provided in the additional raw material supply line 70. The additional raw material supply control means 171 has a fourth adjustment valve 172 as additional raw material supply means, and a fourth controller 173.
The additional raw material supply control means 171 transmits a control signal from the fourth controller 173 to the fourth adjustment valve 172 and controls the operation of the fourth adjustment valve 172, thereby controlling the supply amount of additional raw material oil.
The temperature of the additional raw oil in the additional raw oil supply line 70 is preferably heated to a temperature at which the raw oil and the molten waste plastics can be mixed while maintaining the molten state of the molten waste plastics, similar to the temperature of the raw oil in the first branch line 11.
The additional feedstock oil in the additional feedstock oil supply line 70 is heated by additional feedstock temperature control means (not shown, for example, a heat exchanger, a heater, etc.) to, for example, 80° C. or more and 240° C. or less, preferably 160° C. or more and 230° C. or less. The temperature of the additional feedstock oil is the set temperature of the additional feedstock temperature control means.
The number and installation locations of the additional raw material temperature control means are not particularly limited.
The additional feedstock oil supply line 70 may be connected to a storage tank for storing the additional feedstock oil. In addition, the additional feedstock oil supply line 70 may be, for example, the second branch line 12 connected to the first transport line 10, which is used as the additional feedstock oil supply line 70, so that the additional feedstock oil can be supplied from the first transport line 10 to the kneader 20.
The number of additional feedstock oil supply lines 70 is not limited, and may be one or two or more.

<Action>
In the treatment system 500 of the sixth embodiment, waste plastics are decomposed together with raw oil in the following manner.
The molten waste plastic is prepared in the same manner as in the first embodiment.
Additional raw material oil transported from the additional raw material oil supply line 70 is supplied to the outlet side of the kneader 20 and mixed with the molten waste plastic to prepare a mixture of molten waste plastic and additional raw material oil (hereinafter also referred to as ``molten waste plastic mixed oil C'').
The prepared molten waste plastic mixed oil C is transported through the molten waste plastic supply line 15, as in the first embodiment, and at the junction C2, it is merged (mixed) with the raw oil transported from the second branch line 12 and supplied to the line mixer 30.
The subsequent steps are the same as those in the first embodiment.

＜Effects＞
In the sixth embodiment of the treatment system 500, compared to the first embodiment, the molten waste plastic is further mixed with additional raw material oil transported via an additional raw material oil supply line 70 in the kneader 20 to prepare the molten waste plastic mixed oil C.
By appropriately selecting the type of additional raw material oil, the mixability of the molten waste plastic mixed oil C can be further improved depending on the properties of the waste plastic.
Therefore, according to the treatment system 500 of the sixth embodiment, the decomposability of waste plastics can be improved, and the decomposability of raw oil (including additional raw oil) can also be improved.
In addition, in the treatment system 500 of the sixth embodiment, by appropriately selecting the type of additional raw oil, the mixability of the molten waste plastic mixed oil C can be further improved, so that the preparation of the mixture for decomposition treatment in the line mixer 30 becomes easier, and it becomes easier to obtain a mixture for decomposition treatment with a small fluctuation range of viscosity. As a result, it is considered that the mixture for decomposition treatment can be transported stably and smoothly to the RFCC device 50, and the waste plastic can be decomposed efficiently.

Next, we will explain the configuration common to the first to sixth embodiments. Hereinafter, the reference symbols may be omitted.

<Waste plastic>
Examples of waste plastics include non-chlorinated plastics, chlorinated plastics, and mixtures thereof.
Examples of non-chlorinated plastics include polyethylene, polypropylene, propylene ethylene copolymers, polystyrene, polybutene, ethylene oligomers, butene oligomers, styrene oligomers, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, nylon, epoxy resins, and phenolic resins.
Examples of polyethylene include high density polyethylene, low density polyethylene, and linear low density polyethylene.
Examples of chlorinated plastics include polyvinyl chloride and polyvinylidene chloride.

The waste plastics preferably include at least any one of waste plastics derived from vinyl polymers (e.g., polyethylene, polypropylene, propylene-ethylene copolymer, polystyrene, polybutene, ethylene oligomer, butene oligomer, and styrene oligomer, etc.).
It is more preferable that the waste plastics include at least one of polyethylene-derived waste plastics and polypropylene-derived waste plastics.

It is preferable that the waste plastics not include waste plastics derived from polystyrene or ethylene vinyl acetate.

<Feedstock oil>
The feedstock oil is not particularly limited, but is preferably at least one selected from the group consisting of heavy cracked gas oil (HCO), cracked residual oil (CLO), atmospheric residual oil (RC), desulfurized residual oil (DSRC), desulfurized vacuum gas oil (VHHGO), undesulfurized vacuum gas oil (VGO), undesulfurized vacuum residual oil (VC), and mineral oil (e.g., HG500 (mineral oil of 500 neutral fraction)), and more preferably at least one selected from the group consisting of desulfurized vacuum gas oil (VHHGO), heavy cracked gas oil (HCO), desulfurized residual oil (DSRC), and mineral oil.
In addition, the first transport line 10 for transporting the raw oil may be connected to, for example, an HCO storage tank or a CLO storage tank so as to directly supply at least one of heavy cracked light oil (HCO) and cracked residual oil (CLO) recovered in the FCC unit or the RFCC unit.
In addition, the first transport line 10 may be connected, for example, to a desulfurized residual oil (DSRC) storage tank so that the desulfurized residual oil (DSRC) produced in a heavy oil direct desulfurization unit can be directly supplied.

<Additional feedstock oil>
The additional feedstock oil may be at least one selected from the group consisting of the above-mentioned feedstock oils (heavy cracked gas oil, cracked residual oil, atmospheric residual oil, desulfurized residual oil, desulfurized vacuum gas oil, undesulfurized vacuum gas oil, undesulfurized vacuum residual oil, and mineral oil), light hydrocarbon oil, naphtha, gas oil, and heavy hydrocarbon oil different from the above-mentioned feedstock oils.

<Decomposition treatment device>
Examples of the cracking treatment unit include a catalytic cracking unit (FCC unit), a residual fluid catalytic cracking unit (RFCC unit) (one embodiment of an FCC unit), and a hydrocracking unit.
From the viewpoint of improving the decomposition property of waste plastics, the cracking treatment device is preferably a catalytic cracking device (FCC device) or a residual oil catalytic cracking device (RFCC device).

<Kinematic Viscosity of Mixture for Decomposition Treatment>
The mixture for decomposition treatment prepared in the mixing device (a line mixer in the first to sixth embodiments) preferably has a kinetic viscosity at 160°C of 1 mm2/s or more and ^{60 mm2} /s or less, in order to improve the decomposition ability of waste plastics.
The kinematic viscosity at 160° C. is a value measured in accordance with JIS K 2283 (2000) “Crude oil and petroleum products--Kinematic viscosity test method and viscosity index calculation method”.

Methods for controlling the kinetic viscosity of the cracking mixture at 160°C within a predetermined range include, for example, a method in which the waste plastic supply control means 25 controls the amount of waste plastic supplied or the amount of melted molten waste plastic, and each feedstock supply control means controls the amount of each feedstock oil supplied. Methods for controlling the kinetic viscosity of the cracking mixture at 160°C within a predetermined range also include a method in which the melting conditions of the kneader (e.g., temperature, screw rotation speed, time, etc.), the mixing conditions of the line mixer (e.g., temperature, stirring means rotation speed, time, etc.), the temperature of each branch line, and the temperature of each transport line are controlled.

Specifically, the following control method is preferred.
The waste plastic supply control means 25 controls the supply amount of the waste plastic so that the ratio (total supply amount of the raw oil / melted amount of the molten waste plastic) of the total supply amount of the raw oil (the raw oil supplied from the kneader 20 to the line mixer 30) to the melted amount of the molten waste plastic in the decomposition treatment mixture is within a predetermined range (preferably 10 to 200) in mass ratio.
The raw oil supply control means preferably controls the total supply amount of the raw oil so that the ratio of the total supply amount of the raw oil (the raw oil supplied from the kneader to the line mixer) to the melted amount of the molten waste plastics in the mixture for cracking treatment (the total supply amount of the raw oil/the melted amount of the molten waste plastics) falls within a predetermined range in mass ratio. The predetermined range is preferably 10 to 200, more preferably 20 to 200.
The "total supply amount of raw oil supplied from the kneader to the line mixer" is, for example, in the case of Figure 2, the total supply amount of raw oil supplied by the first raw oil supply control means 111 and the third raw oil supply control means 131.
In addition, when any of the treatment systems of the above embodiments has an additional raw material oil supply line and an additional raw material supply control means, the additional raw material supply control means preferably controls the supply amount of the additional raw material oil so that the ratio of the total supply amount of the raw material oil supplied from the kneader to the line mixer and the additional raw material oil supplied from the kneader to the line mixer to the melted amount of molten waste plastic in the cracking treatment mixture (the total supply amount of the raw material oil and the additional raw material oil / the melted amount of the molten waste plastic) is within a predetermined range by mass ratio. The predetermined range is preferably 10 to 200, more preferably 20 to 200.
The "total supply amount of the raw material oil supplied from the kneader to the line mixer and the additional raw material oil supplied from the kneader to the line mixer" is, for example, in the case of Figure 6, the total supply amount of the raw material oil supplied by the second raw material oil supply control means 121 and the additional raw material oil supplied by the additional raw material supply control means 171.

<Viscosity of mixed oil of melted waste plastic>
In any of the processing systems of the above embodiments, it is preferable that the melt viscosity at 200°C of the molten waste plastic mixed oil (e.g., any of molten waste plastic mixed oil A to molten waste plastic mixed oil C) before being supplied to the mixing device is adjusted to a predetermined range (preferably 100 mPa·s or more and 50 million mPa·s or less).
The melt viscosity at 200° C. was measured using a rheometer (MCR302 (product number) manufactured by Anton Paar) under the following conditions using a cone plate as a measuring tool.
<Conditions>
- Cone-plate measuring system: DIN EN (compliant with ISO 3219 and DIN 53019)
・Angular frequency (ω): 0.1 rad/sec to 100 rad/sec ・Measurement temperature: 200°C
・Sample weight: 0.1g to 0.3g

Other Embodiments
In the first to sixth embodiments, the cracking treatment mixture prepared in the line mixer is transported to the junction C1 via the second transport line, and is merged (mixed) with the feed oil transported from the first transport line 10 to the RFCC device 50 at the junction C1, and is supplied to the RFCC device 50, but the present invention is not limited to this. For example, in any of the above embodiments, the cracking treatment mixture prepared in the line mixer may be supplied to the RFCC device directly from the second transport line (without passing through the first transport line).

In the fifth embodiment, the two line mixers 30, 30A are arranged in series and the remaining line mixer 30B is arranged in parallel to the two line mixers 30, 30A. However, the present invention is not limited to this.
In addition, in the fifth embodiment A, the two line mixers 30, 30A are arranged in series and the remaining two line mixers 30B, 30C are arranged in parallel to the two line mixers 30, 30A. However, the present invention is not limited to this.
For example, in any of the above embodiments, multiple line mixers may be arranged in series, in parallel, or in a combination of series and parallel. The multiple line mixers may be the same or different from each other. The number and arrangement of the line mixers are also not limited.
In the fifth embodiment and the fifth embodiment A, two kneaders are installed in parallel, and molten waste plastics are prepared from the waste plastics supplied to each kneader. However, the present invention is not limited to this. For example, in any of the above embodiments, three or more kneaders may be arranged. The multiple kneaders may be the same or different from each other. The number of kneaders is not limited.

In the sixth embodiment, the additional raw oil supply line 70 is connected to the kneader 20, but this is not limited thereto. For example, in any of the above embodiments, the additional raw oil supply line may be connected to at least one of the kneader, the line mixer, the first branch line, the second branch line, the third branch line, the molten waste plastic supply line, the first transport line, and the second transport line. The number of additional raw oil supply lines is also not limited.

In any of the processing systems of the above-described embodiments, a known melting device may be used in place of the kneader 20, 20A.
In any of the processing systems according to the above embodiments, a known mixing device may be used in place of the line mixers 30, 30A, 30B, and 30C.
In any of the treatment systems of the above-described embodiments, the RFCC unit 50 may be replaced with a known cracking treatment unit used in the field of oil refining, for example.

The following describes examples of the present invention. The present invention is not limited to these examples.

[Preparation of mixture for decomposition treatment 1]
Example 1
Using compacted cylindrical polypropylene (diameter 8 mm × length 10 to 15 mm) as waste plastic, molten polypropylene (hereinafter also referred to as "molten PP") was prepared under the following conditions.
(conditions)
・Kneading machine: Shibaura Machine Co., Ltd.: Twin-screw kneading extruder (model number TEM-37SS)
Melting temperature: 200°C
Melting amount: 30 kg/hr

Next, DSRC was added as a raw material oil to molten PP (10 kg) so that the ratio of desulfurized residual oil (DSRC) to molten PP (DSRC/molten PP) was 1 by mass, thereby preparing a mixture of molten PP and DSRC (20 kg) (hereinafter also referred to as "molten PP mixed oil 1").
The melt viscosity of the molten PP mixed oil 1 was measured by the above-mentioned method. The melt viscosity of the molten PP mixed oil 1 at 200° C. was 1,000,000 mPa·s.

Next, DSRC (147 g) was further added to the molten PP mixed oil 1 (6 g) so that the ratio of desulfurized residual oil (DSRC) to molten PP (DSRC/molten PP) was 50 by mass. Thereafter, the mixture of the molten PP mixed oil 1 and the DSRC was mixed using a batch mixer under the following conditions to prepare a mixture for cracking treatment.
The kinetic viscosity of the mixture for decomposition treatment was measured by the method described above. The kinetic viscosity of the mixture for decomposition treatment at 160° C. was 10 mm ² /s.
(conditions)
・Batch mixer: Primix Corporation: Homo Mixer MKII Homo Mixer Blade ・Rotation speed: 900 rpm
Temperature: 220°C
Time: 30 seconds

Next, the mixture for cracking treatment of Example 1 was cracked under the following conditions using a small reaction evaluation apparatus (MAT apparatus) equivalent to an FCC apparatus.
(conditions)
Small reaction evaluation device: Kayser: ACE R+
Reaction temperature: 530°C
Pressure: 0.05MPaG
Time: 90 seconds (oil flow time)
Catalyst/decomposition mixture (mass ratio): 6
Catalyst: 9g
Catalyst type: FCC equilibrium catalyst
(FCC equilibrium catalyst extracted from actual equipment)

Example 2
A mixture for decomposition treatment was prepared and decomposed in the same manner as in Example 1, except that the "catalyst/mixture for decomposition treatment (mass ratio)" was changed to 5 compared to Example 1.

Example 3
A mixture for decomposition treatment was prepared and decomposed in the same manner as in Example 1, except that the "catalyst/mixture for decomposition treatment (mass ratio)" was changed to 3.98.

Comparative Example 1
In the same manner as in Example 1, DSRC (not including molten PP) was decomposed in a small reaction evaluation device.

Comparative Example 2
The DSRC was decomposed in the same manner as in Comparative Example 1, except that the "catalyst/DSRC (mass ratio)" was changed to 5 in Comparative Example 1.

Comparative Example 3
DSRC was decomposed in the same manner as in Comparative Example 1, except that the "catalyst/DSRC (mass ratio)" was changed to 3.98.

<Decomposition evaluation 1>
The decomposition properties of the decomposition treatment mixtures of Examples 1 to 3 and the DSRCs of Comparative Examples 1 to 3 were evaluated by the Microactivity Test (MAT), and the results are shown in Table 1.
The values in Table 1 represent the percentage of the mass of each component relative to the mass of DSRC in the product oil obtained by cracking.
The conversion rate (mass %) was calculated from the following formula (1).
Conversion rate (mass%) = 100 - (LCO + CLO) ... (1)

Explanation in Table 1: Dry Gas represents methane, ethane and ethylene.
FG stands for gasoline.
LCO stands for gas cracked oil (light gas cracked oil + heavy gas cracked oil).
CLO stands for cracked residual oil.
COKE stands for coke.
The same applies to Table 2 described later.

As a result of comparing Example 1 and Comparative Example 1, Example 1, in which a mixture for cracking treatment containing molten PP was cracked, showed improved conversion, FG yield, and yield of liquefied petroleum gases (propane, propylene, n-butane, isobutane, and butylene) compared with Comparative Example 1, in which only DSRC was cracked. In particular, the propylene yield, isobutane yield, and butylene yield were improved.
The results of comparing Example 2 with Comparative Example 2 and the results of comparing Example 3 with Comparative Example 3 were similar.
According to this example, it was confirmed that the waste plastics in the mixture for decomposition treatment can be converted into useful liquefied petroleum gases together with the raw material oil, and the decomposition property of the waste plastics can be improved.

[Preparation of mixture for decomposition treatment 2]
Example 4
Molten PP was prepared under the same conditions as in Example 1 using the same waste plastics as in Example 1. However, in Example 4, the waste plastics were melted while supplying HG500 as a raw material oil to the outlet side of the kneader so that the ratio of mineral oil (HG500) to molten PP (10 kg) (HG500/molten PP) was 1 by mass. This operation produced a mixture (20 kg) of molten PP and HG500 (hereinafter also referred to as "molten PP mixed oil 2").
The melt viscosity of the molten PP mixed oil 2 was measured by the above-mentioned method. The melt viscosity of the molten PP mixed oil 2 at 200° C. was 1,000,000 mPa·s.

Next, HG500 (96 g) was further added to the molten PP mixed oil 2 (8 g) so that the ratio of HG500 to molten PP (HG500/molten PP) was 25 by mass. Thereafter, the mixture of the molten PP mixed oil 2 and HG500 was mixed under the following conditions to prepare a mixture for cracking treatment.
The kinetic viscosity of the mixture for decomposition treatment was measured by the method described above. The kinetic viscosity of the mixture for decomposition treatment at 160° C. was 21 mm ² /s.

Next, the mixture for decomposition treatment of Example 4 was decomposed in the same manner as in Example 1 using a small reaction evaluation device (MAT device) equivalent to an FCC device.

Example 5
A mixture for decomposition treatment was prepared and decomposed in the same manner as in Example 4, except that the "catalyst/mixture for decomposition treatment (mass ratio)" was changed to 5 in comparison with Example 4.

Comparative Example 4
In the same manner as in Example 4, HG500 (not including molten PP) was decomposed in a small reaction evaluation device.

Comparative Example 5
HG500 was decomposed in the same manner as in Comparative Example 4, except that the "catalyst/HG500 (mass ratio)" was changed to 5 in Comparative Example 4.

<Decomposition evaluation 2>
The decomposition properties of the decomposition treatment mixtures of Examples 4 and 5 and HG500 of Comparative Examples 4 and 5 were evaluated by the Microactivity Test (MAT), and the results are shown in Table 2.
The values in Table 2 represent the percentage of the mass of each component relative to the mass of HG500 in the product oil obtained by cracking.
The conversion rate (mass %) was calculated from the above formula (1).

As a result of comparing Example 4 and Comparative Example 4, Example 4, in which a mixture for cracking treatment containing molten PP was cracked, showed improved conversion, FG yield, and yield of liquefied petroleum gases (propane, propylene, n-butane, isobutane, and butylene) compared with Comparative Example 4, in which only HG500 was cracked. In particular, the propylene yield, isobutane yield, and butylene yield were improved.
The results of comparing Example 5 and Comparative Example 5 were similar.
According to this example, it was confirmed that the waste plastics in the mixture for decomposition treatment can be converted into useful liquefied petroleum gases together with the raw material oil, and the decomposition property of the waste plastics can be improved.

From the above results, it is believed that the decomposition of waste plastics can be improved by using a waste plastic processing system equipped with a mixing device that can prepare a decomposition mixture with a kinetic viscosity adjusted to a predetermined range, and a decomposition processing device, etc.

The waste plastic processing system of the present invention can be used industrially because it can improve the effective utilization rate of waste plastic.

10...first transport line, 11...first branch line, 12...second branch line, 13...third branch line, 13A...first branch line, 13B...second branch line, 14...second transport line, 15...molten waste plastic supply line, 20, 20A...kneader, 21...feeder, 22...hopper, 23...waste plastic supply line, 24...feeder controller, 25...waste plastic supply control means, 30, 30A, 30B...line mixer, 40...second storage tank, 41...centrifugal pump, 43, 44...gas venting line, 50...RFCC device, 60...first storage Tank, 61... gear pump, 70... additional feedstock oil supply line, 100, 200, 300, 300A, 400, 500... treatment system, 111... first feedstock oil supply control means, 112... first control valve, 113... first controller, 121... second feedstock oil supply control means, 122... second control valve, 123... second controller, 131... third feedstock oil supply control means, 132... third control valve, 133... third controller, 151... first mixed oil branch line, 152... second mixed oil branch line, 171... additional feedstock supply control means, 172... fourth control valve, 173... fourth controller, HG... heat exchanger.

Claims (18)

A waste plastic processing system for processing waste plastic,
A melting device for preparing molten waste plastic by melting the waste plastic;
A mixer for mixing the molten waste plastic with a raw material oil to prepare a mixture for decomposition treatment;
A molten waste plastic supply line that connects the melting device and the mixing device and supplies at least the molten waste plastic from the melting device to the mixing device;
A cracking treatment device that cracks both the molten waste plastics and the raw oil in the mixture for cracking treatment;
a first transportation line connected to the cracking treatment unit and configured to transport the feedstock oil to the cracking treatment unit;
At least one of a first branch line that connects the first transport line and the melting device and supplies the raw oil from the first transport line to the melting device, a second branch line that connects the first transport line and the molten waste plastic supply line and supplies the raw oil from the first transport line to the molten waste plastic supply line, and a third branch line that connects the first transport line and the mixing device and supplies the raw oil from the first transport line to the mixing device;
a second transport line that transports the mixture for decomposition treatment from the mixing device to at least one of the first transport line and the decomposition treatment device;
A waste plastic supply control means for controlling the amount of the waste plastic supplied to the melting device;
a feed oil supply control means for controlling a supply amount of the feed oil supplied from at least one of the first branch line, the second branch line, and the third branch line;
and a feed oil temperature control means for controlling the temperature of the feed oil transported through the first transport line.
Waste plastic processing system. In the waste plastic processing system according to claim 1,
The waste plastic processing system further includes one or more additional feedstock oil supply lines for supplying at least one other additional feedstock oil selected from the group consisting of the feedstock oil, light hydrocarbon oil, naphtha, diesel, and heavy hydrocarbon oil different from the feedstock oil, and the additional feedstock oil supply line is different from the first transport line,
The additional raw oil supply line is connected to at least one of the melting device, the mixing device, the first branch line, the second branch line, the third branch line, the molten waste plastic supply line, and the second transportation line;
Waste plastic processing system. In the waste plastic processing system according to claim 1 or 2,
The waste plastic supply control means controls the amount of the waste plastic supplied to the melting device, thereby controlling the amount of the molten waste plastic.
Waste plastic processing system. In the waste plastic processing system according to any one of claims 1 to 3,
The feedstock oil is at least one selected from the group consisting of heavy cracked gas oil, cracked residual oil, atmospheric residual oil, desulfurized residual oil, desulfurized vacuum gas oil, undesulfurized vacuum gas oil, undesulfurized vacuum residual oil, and mineral oil;
Waste plastic processing system. In the waste plastic processing system according to any one of claims 1 to 4,
The feedstock oil is at least one selected from the group consisting of desulfurized vacuum gas oil, heavy cracked gas oil, desulfurized residual oil and mineral oil,
Waste plastic processing system. In the waste plastic processing system according to any one of claims 1 to 5,
A waste plastic processing system having at least the second branch line. In the waste plastic processing system according to any one of claims 1 to 6,
At least the first branch line and the third branch line,
Waste plastic processing system. In the waste plastic processing system according to any one of claims 1 to 7,
The waste plastic processing system further includes a first storage tank between the melting device and the mixing device,
The first storage tank stores at least a mixture of the molten waste plastic and the raw oil supplied from at least one of the first branch line and the second branch line.
Waste plastic processing system. In the waste plastic processing system according to any one of claims 1 to 8,
The waste plastic processing system further includes a second storage tank between the mixing device and the decomposition processing device,
The second storage tank stores at least the decomposition treatment mixture transported from the second transport line.
Waste plastic processing system. In the waste plastic processing system according to claim 8 or claim 9,
At least one of the first storage tank and the second storage tank is provided with a gas venting means.
Waste plastic processing system. In the waste plastic processing system according to any one of claims 1 to 10,
The waste plastic includes at least one of polyethylene-derived waste plastic and polypropylene-derived waste plastic,
Waste plastic processing system. In the waste plastic processing system according to any one of claims 1 to 11,
The melting device is provided in plurality.
Waste plastic processing system. In the waste plastic processing system according to any one of claims 1 to 12,
The melting device is a kneader.
Waste plastic processing system. In the waste plastic processing system according to any one of claims 1 to 13,
The mixing device includes a plurality of the mixing devices.
Waste plastic processing system. The waste plastic processing system according to claim 14,
The plurality of mixing devices are arranged in parallel or in series.
Waste plastic processing system. In the waste plastic processing system according to any one of claims 1 to 15,
The mixing device is a line mixer.
Waste plastic processing system. In the waste plastic processing system according to any one of claims 1 to 16,
The cracking treatment device is a fluid catalytic cracking device.
Waste plastic processing system. In the waste plastic processing system according to any one of claims 1 to 17,
The waste plastic supply control means controls the supply amount of the waste plastic so that the ratio of the melted amount of the molten waste plastic in the decomposition treatment mixture to the total supply amount of the raw material oil (the total supply amount of the raw material oil / the melted amount of the molten waste plastic) is within a predetermined range in mass ratio;
The raw oil supply control means controls the supply amount of the raw oil so that the ratio of the total supply amount of the raw oil to the melted amount of the molten waste plastic in the decomposition treatment mixture (the total supply amount of the raw oil / the melted amount of the molten waste plastic) is within a predetermined range by mass ratio.
Waste plastic processing system.

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