JP7709351B2 - Mixture for decomposition of waste plastics and method for producing the mixture for decomposition of waste plastics - Google Patents

Description

The present invention relates to a mixture for waste plastic decomposition processing and a method for producing the mixture for waste plastic decomposition processing.

The low rate of effective utilization of waste plastics and environmental pollution caused by marine plastic waste, etc., 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 producing 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.

Special Publication No. 2014-518906 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, the plastic melt solution obtained by the method of Patent Document 1 has insufficient mixability because the solvent is simply added. As a result, the decomposition ability of the plastic material may not be sufficiently improved when decomposing the plastic material in a depolymerization reactor.
Patent Document 2 describes 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. However, since Patent Document 2 does not pay any attention to the solubility of the hydrocarbon polymer in the hydrocarbon oil, the mixture of the hydrocarbon polymer and the hydrocarbon oil obtained by the method of Patent Document 2 is likely to have insufficient mixability. As a result, when cracking in an FCC unit, the decomposition ability of the hydrocarbon polymer may not be sufficiently improved.

The present invention aims to provide a mixture for waste plastic decomposition processing that can improve the decomposition ability of waste plastic when decomposed in a decomposition processing device, and a method for producing the mixture for waste plastic decomposition processing.

According to one aspect of the present invention, there is provided a mixture for decomposing waste plastics in a decomposition treatment device,
The mixture for waste plastic decomposition treatment is
The waste plastic melting process includes melted waste plastic and raw material oil,
The following formulas (1), (2) and (3) are satisfied,
The waste plastic decomposition processing mixture is provided in such a way that when the mixture for waste plastic decomposition processing is passed through a 40 mesh filter, the remaining ratio of filtered matter to the waste plastic contained in the mixture for waste plastic decomposition processing (filtered matter/waste plastic contained in the mixture for waste plastic decomposition processing) is 0.35 or less in mass ratio.
0.850g/cm ³ ≦Density (15°C) ≦1.150g/cm ³ ... (Math. 1)
1.400≦refractive index (70° C.)≦1.650 (Equation 2)
4.0mm ² /s≦Kinematic viscosity (200°C)≦20.0mm ² /s (Math. 3)

In the mixture for waste plastic decomposition processing 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 vacuum residual oil, mineral oil, heavy gas oil, desulfurized heavy gas oil, desulfurized vacuum residual oil, and deasphalted oil.

In the mixture for waste plastic decomposition processing according to one embodiment of the present invention, it is preferable that the waste plastic contains at least one of waste plastic derived from polyethylene and waste plastic derived from polypropylene.

According to one aspect of the present invention, there is provided a method for producing a mixture for waste plastic decomposition treatment for decomposing waste plastic in a decomposition treatment device, comprising the steps of:
A first preparation step of preparing a molten waste plastic mixed oil by mixing a molten waste plastic, which is a melted product of the waste plastic, with a first raw material oil;
A second preparation step of preparing a mixture for waste plastic decomposition treatment by mixing the molten waste plastic mixed oil prepared in the first preparation step with a second raw material oil,
The first feedstock and the second feedstock satisfy the following formulas (4), (5), (6), and (7), respectively:
When the mixture for waste plastic decomposition treatment prepared in the second preparation step is passed through a 40 mesh filter, the ratio of the residue to the waste plastic contained in the mixture for waste plastic decomposition treatment (the residue/the waste plastic contained in the mixture for waste plastic decomposition treatment) is 0.35 or less in mass ratio;
The first feedstock and the second feedstock are the same or different from each other;
A method for producing a mixture for waste plastic decomposition processing is provided.
0.850g/cm ³ ≦Density (15°C) ≦1.150g/cm ³ ... (Math. 4)
1.400≦refractive index (70° C.)≦1.650 (Equation 5)
3.0mm ² /s≦Kinematic viscosity (75°C)≦55.0mm ² /s (Math. 6)
240g/mol≦molecular weight≦1000 g/mol…(Math. 7)

In one embodiment of the method for producing a mixture for waste plastic decomposition processing according to the present invention, it is preferable that the first feedstock oil and the second feedstock oil each have a hydrogen bond term (δh) of 1.5 or less and a dipole-dipole term (δp) of 4.0 or less, as expressed by the Hansen solubility parameters.

In the method for producing a mixture for waste plastic decomposition processing according to one embodiment of the present invention, the first feedstock oil and the second feedstock oil are 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 vacuum residual oil, mineral oil, heavy gas oil, desulfurized heavy gas oil, desulfurized vacuum residual oil, and deasphalted oil.

In the method for producing a mixture for waste plastic decomposition processing according to one aspect of the present invention, it is preferable that the waste plastic contains at least one of polyethylene-derived waste plastic and polypropylene-derived waste plastic.

According to one aspect of the present invention, it is possible to provide a mixture for waste plastic decomposition processing that can improve the decomposition property of waste plastic when decomposed in a decomposition processing device, and a method for manufacturing the mixture for waste plastic decomposition processing.

FIG. 11 is a schematic diagram of an example of a processing system used in the manufacturing method according to the second embodiment. FIG. 11 is a schematic diagram of another example of a processing system used in the manufacturing method according to the second embodiment. FIG. 11 is a schematic diagram of another example of a processing system used in the manufacturing method according to the second embodiment. 6 is a cross-sectional view taken along line II in FIG. 5 when the specific surface area enlarging means is a stretched plate. 6 is a cross-sectional view taken along line II in FIG. 5 when the specific surface area enlarging means is a perforated plate. FIG. 11 is a schematic diagram of another example of a processing system used in the manufacturing method according to the second embodiment. FIG. 11 is a schematic diagram of another example of a processing system used in the manufacturing method according to the second embodiment. FIG. 11 is a schematic diagram of another example of a processing system used in the manufacturing method according to the second embodiment. FIG. 11 is a schematic diagram of another example of a processing system used in the manufacturing method according to the second embodiment. 1A and 1B are top and front views of an example of a fusing device including a helical ribbon vane. FIG. 1 is a schematic diagram of an example of a dissolution apparatus. FIG. 1 is a schematic diagram of an example of a dissolution apparatus. FIG. 1 is a schematic diagram of an example of a dissolution apparatus. FIG. 1 is a schematic diagram of an example of a dissolution apparatus. FIG. 1 is a schematic diagram of an example of a dissolution apparatus.

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 decomposition processing mixture of this embodiment (hereinafter also referred to as the decomposition processing mixture) is a waste plastic decomposition processing mixture for decomposing waste plastic in a decomposition processing device, and the waste plastic decomposition processing mixture contains molten waste plastic, which is a melted product of waste plastic, and raw material oil, and satisfies the following mathematical formulas (Mathematical Formula 1), (Mathematical Formula 2), and (Mathematical Formula 3).When the waste plastic decomposition processing mixture is passed through a 40 mesh filter, the remaining ratio of the filtered matter to the waste plastic contained in the waste plastic decomposition processing mixture (the filtered matter/the waste plastic contained in the waste plastic decomposition processing mixture) is 0.35 or less in mass ratio.
0.850g/cm ³ ≦Density (15°C) ≦1.150g/cm ³ ... (Math. 1)
1.400≦refractive index (70° C.)≦1.650 (Equation 2)
4.0mm ² /s≦Kinematic viscosity (200°C)≦20.0mm ² /s (Math. 3)

The filtered matter refers to the substances (unit: kg) that could not pass through a 40 mesh filter out of the waste plastics (waste plastics dissolved in the raw oil) contained in the mixture for decomposition treatment.
For example, when 49 kg of raw material oil and 1.0 kg of molten waste plastic are mixed to prepare 50 kg of a mixture for decomposition treatment, and this 50 kg mixture for decomposition treatment is passed through a 40 mesh filter, if the amount of material (filtered matter) that could not pass through the filter is 0.35 kg,
The remaining ratio of the filtrate (filtrate/waste plastic contained in the mixture for decomposition treatment) was calculated to be 0.35 (0.35/1.0) in mass ratio.

The mixture for decomposition treatment of this embodiment satisfies the formulas (1) to (3), and the residual ratio of the filtrate (the filtrate/waste plastic contained in the mixture for decomposition treatment) is 0.35 or less in mass ratio.
The residual ratio of the filtered matter being 0.35 or less in terms of mass ratio indicates that the molten waste plastics and the raw material oil are mixed in a nearly uniform state in the mixture for decomposition treatment.
Therefore, according to the mixture for decomposition treatment of this embodiment, the decomposition property of waste plastics can be improved when decomposed in a decomposition treatment device.
The mixture for decomposition treatment of this embodiment can be obtained, for example, by the manufacturing method for a mixture for decomposition treatment of the second embodiment described later.

In the decomposition treatment mixture of this embodiment, the preferred ranges of formula (1), formula (2), and formula (3) are as follows:

<Density (15℃)>
In the decomposition treatment mixture of this embodiment, it is preferable that the density (15°C) satisfies the following formula (Mathematical Formula 1A).
Density (15°C) indicates the density at 15°C.
0.900g/cm ³ ≦Density (15°C) ≦1.050g/cm ³ ... (Math 1A)
The density (15°C) of the mixture for cracking treatment can be measured in accordance with JIS K 2249-1 (2011) "Crude oil and petroleum products-Determination of density Part 1: Vibration method" or JIS K 2249-2 (2011) "Crude oil and petroleum products-Determination of density Part 2: Hydrometer method".

<Refractive index (70° C.)>
In the decomposition treatment mixture of this embodiment, the refractive index (70°C) preferably satisfies the following formula (Mathematical formula 2A): The refractive index (70°C) indicates the refractive index at 70°C.
1.480≦Refractive index (70° C.)≦1.620... (Number 2A)
The refractive index (70° C.) of the decomposition treatment mixture can be measured using a product manufactured by Atago Co., Ltd. (product number: RX-7000α).

<Kinematic viscosity (200°C)>
In the decomposition treatment mixture of this embodiment, the kinetic viscosity (200° C.) preferably satisfies the following formula (Mathematical Formula 3A).
The kinetic viscosity (200°C) indicates the kinetic viscosity at 200°C.
4.0mm ² /s≦Kinematic viscosity (200°C)≦12.0mm ² /s (3A)
The kinetic viscosity (200°C) of the decomposition treatment mixture is a value estimated in accordance with the kinetic viscosity estimation method at any temperature in JIS K2207, by measuring the kinetic viscosity at 150°C and 180°C in accordance with the high temperature kinetic viscosity test method for "petroleum asphalt" in JIS K2207 (1996).

<Remaining ratio of filtered matter>
When the decomposition treatment mixture of this embodiment is passed through a 40 mesh filter, the remaining ratio of the filtrate to the waste plastics contained in the decomposition treatment mixture (filtrate/waste plastics contained in the decomposition treatment mixture) is 0.35 or less in mass ratio.
The lower the residual ratio of the filtrate (the filtrate/the waste plastics contained in the mixture for decomposition treatment) is, the more preferable.

<Raw oil>
The feedstock oil contained in the cracking treatment mixture 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, HPRC), desulfurized residual oil (DSRC), desulfurized vacuum gas oil (VHHGO), undesulfurized vacuum gas oil (VGO), undesulfurized vacuum residual oil (VC), mineral oil (e.g., HG-500 (mineral oil of 500 neutral fraction), etc.), heavy gas oil (HGO), desulfurized heavy gas oil (DS-HGO), desulfurized vacuum residual oil (DS-VC), and deasphalted oil (DAO).

<Waste plastic>
Examples of waste plastics include non-chlorinated plastics, chlorinated plastics, and mixtures thereof.
The shape of the waste plastic is not particularly limited, and is preferably selected appropriately depending on the specifications of the melting device.
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.
The waste plastics are preferably substantially free of waste plastics derived from polystyrene and waste plastics derived from ethylene vinyl acetate. Substantially free means that the content of waste plastics derived from polystyrene and waste plastics derived from ethylene vinyl acetate is 10% by mass or less, preferably 5% by mass or less, based on the total amount of the waste plastics.

Second Embodiment
The second embodiment of the manufacturing method for a mixture for waste plastic decomposition processing (hereinafter also referred to as the manufacturing method for the second embodiment) is a manufacturing method for a mixture for waste plastic decomposition processing for decomposing waste plastics in a decomposition processing device, and has a first preparation step of preparing a molten waste plastic mixed oil by mixing molten waste plastic, which is a molten product of waste plastic, with a first raw material oil, and a second preparation step of preparing a mixture for waste plastic decomposition processing by mixing the molten waste plastic mixed oil prepared in the first preparation step with a second raw material oil.
The first feedstock and the second feedstock satisfy the following formulas (4), (5), (6), and (7), respectively.
When the mixture for waste plastic decomposition processing prepared in the second preparation step is passed through a 40 mesh filter, the remaining ratio of the filtered matter to the waste plastic contained in the mixture for waste plastic decomposition processing (the filtered matter/the waste plastic contained in the mixture for waste plastic decomposition processing) is 0.35 or less in mass ratio.
The first feedstock and the second feedstock may be the same as or different from one another.
0.850g/cm ³ ≦Density (15°C) ≦1.150g/cm ³ ... (Math. 4)
1.400≦refractive index (70° C.)≦1.650 (Equation 5)
3.0mm ² /s≦Kinematic viscosity (75°C)≦55.0mm ² /s (Math. 6)
240g/mol≦molecular weight≦1000g/mol…(Math. 7)

The inventors have discovered that by mixing molten waste plastics with a first raw material oil having specific properties (first preparation step), and further mixing the molten waste plastic mixed oil prepared in the first preparation step with a second raw material oil having specific properties (second preparation step), when the mixture for decomposition treatment obtained in the second preparation step is passed through a 40 mesh filter, the remaining ratio of the filtered matter to the waste plastics contained in the mixture for decomposition treatment (the filtered matter/the waste plastics contained in the mixture for decomposition treatment) can be made to be 0.35 or less in mass ratio.
The residual ratio of the filtered matter being 0.35 or less in terms of mass ratio indicates that the molten waste plastics and the raw material oil are mixed in a nearly uniform state in the mixture for decomposition treatment.
Therefore, according to the manufacturing method of the second embodiment, a mixture for decomposition treatment can be obtained that can improve the decomposition property of waste plastics when decomposed in a decomposition treatment device.
By the manufacturing method of the second embodiment, for example, the decomposition treatment mixture of the first embodiment can be obtained.

In the manufacturing method of the second embodiment, the preferred ranges of formula (4), formula (5), formula (6) and formula (7) are as follows:

<Density (15℃)>
It is preferable that the density (15° C.) of each of the first and second feedstocks satisfies the following formula (Mathematical Formula 4A).
0.900g/cm ³ ≦Density (15°C) ≦1.050g/cm ³ ... (Number 4A)
The densities (15° C.) of the first feedstock and the second feedstock can be measured in the same manner as the density (15° C.) of the mixture for cracking treatment described in the first embodiment.

<Refractive index (70° C.)>
In the first feedstock and the second feedstock, it is preferable that the refractive index (70° C.) satisfies the following formula (Mathematical Formula 5A).
1.480≦Refractive index (70° C.)≦1.620... (Number 5A)
The refractive index (70° C.) of the first feed oil and the second feed oil can be measured in the same manner as the refractive index (70° C.) of the mixture for cracking treatment described in the first embodiment.

<Kinematic viscosity (75°C)>
In the first and second stock oils, the kinematic viscosity (75° C.) preferably satisfies the following formula (6A).
3.0mm ² /s≦Kinematic viscosity (75°C)≦45.0mm ² /s…(Math. 6A)
The kinematic viscosity (75° C.) of the first feedstock and the second feedstock 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”.

<Molecular weight>
In the first feedstock and the second feedstock, it is preferable that the molecular weight satisfies the following formula (7A).
240g/mol≦molecular weight≦500g/mol…(Number 7A)
The molecular weights of the first feedstock and the second feedstock can be calculated in accordance with UOP Method 375-07 (Calculation of UOP Characterization Factor and Estimation of Molecular Weight of Pertroleum Oils).

<Remaining ratio of filtered matter>
In the manufacturing method of the second embodiment, when the decomposition treatment mixture prepared in the second preparation step is passed through a 40 mesh filter, the remaining ratio of the filtrate to the waste plastic contained in the decomposition treatment mixture (filtrate/waste plastic contained in the decomposition treatment mixture) (mass ratio) is preferably as low as possible, as in the first embodiment.

<First feedstock and second feedstock>
The first feedstock oil and the second feedstock oil used in the production method of the second embodiment can be the feedstock oils described in the first embodiment.
The first and second feedstocks are each preferably at least one selected from the group consisting of heavy cracked gas oil (HCO), cracked residual oil (CLO), atmospheric residual oil (RC, HPRC), desulfurized residual oil (DSRC), desulfurized vacuum gas oil (VHHGO), undesulfurized vacuum gas oil (VGO), undesulfurized vacuum residual oil (VC), mineral oil (e.g., HG-500 (mineral oil of 500 neutral fraction), etc.), heavy gas oil (HGO), desulfurized heavy gas oil (DS-HGO), desulfurized vacuum residual oil (DS-VC), and deasphalted oil (DAO).
The first feedstock and the second feedstock may be the same as or different from each other.

Tables 1 and 2 show the types and properties of feedstock oils that can be used as the first feedstock oil and the second feedstock oil. However, the first feedstock oil and the second feedstock oil are not limited to these.
As the first feedstock oil and the second feedstock oil, one or more of the feedstock oils in Tables 1 and 2 can be used in combination so as to satisfy the formula (4), the formula (5), the formula (6) and the formula (7).
For example, atmospheric residual oil (RC, HPRC), undesulfurized vacuum residual oil (VC), desulfurized vacuum residual oil (DS-VC) and deasphalted oil (DAO) do not have a kinetic viscosity (75°C) that satisfies the formula (6) when used alone, but when combined with other feedstock oils, they can be made into a feedstock oil (first feedstock oil or second feedstock oil) whose kinetic viscosity (75°C) satisfies the formula (6).

It is preferable that the first feedstock and the second feedstock each have a hydrogen bond term (δh) represented by the Hansen solubility parameters of 1.5 or less and a dipole-dipole term (δp) of 4.0 or less.
When the hydrogen bonding term (δh) represented by the Hansen solubility parameter is 1.5 or less, the waste plastic is easily dissolved. The smaller the hydrogen bonding term (δh), the more preferable it is.
When the dipole-dipole force term (δp) represented by the Hansen solubility parameter is 4.0 or less, the waste plastic is easily dissolved. The smaller the dipole-dipole force term (δp), the more preferable it is.

The Hansen solubility parameter is a solubility parameter introduced by Hildebrand, which is divided into three components, the London dispersion term (δd), the dipole-dipole term (δp), and the hydrogen bond term (δh), and is expressed in three-dimensional space. The London dispersion term (δd) indicates the effect due to the London dispersion force, the dipole-dipole term (δp) indicates the effect due to the dipole force, and the hydrogen bond term (δh) indicates the effect due to the hydrogen bond force.
The definition and calculation of the Hansen solubility parameter are described in "Hansen Solubility Parameters; A Users Handbook" by Charles M. Hansen (CRC Press, 2007).
The manufacturing method of this embodiment uses parameter values described in the literature.

The first feedstock and the second feedstock may each be a single type of feedstock or a combination of two or more types of feedstock.
When two or more kinds of feedstock oils are used in combination, the hydrogen bond term (δh) of the feedstock oil is the average value of the hydrogen bond term (δh) of each feedstock oil according to the volume ratio. The same applies to the dipole-dipole term (δp) of the feedstock oil.
For example, in the case of a mixed oil obtained by mixing heavy cracked light oil (HCO) having a hydrogen bonding term (δh) of X and residual cracked oil (CLO) having a hydrogen bonding term (δh) of Y in a volume ratio of 6:4 (HCO:CLO), the hydrogen bonding term (δh) of the mixed oil is calculated as (6X + 4Y) / 10.

<Waste plastic>
As the waste plastic used in the manufacturing method of the second embodiment, the waste plastic described in the first embodiment can be used.
The waste plastics preferably include at least one of polyethylene-derived waste plastics and polypropylene-derived waste plastics.

[Production method embodiment 1]
The production method of the second embodiment can be carried out, for example, by using a processing system 100 shown in Fig. 1 (production method aspect 1). In production method aspect 1, a case will be described in which the same type of feedstock oil is used as the first feedstock oil and the second feedstock oil.
In the following description, the ordinal expressions "first" and "second" are intended to distinguish components and do not imply an order.

<Overall composition>
The processing system 100 shown in Fig. 1 includes a kneader 20, a first storage tank 60, a line mixer 30 (an example of a mixing device), a second storage tank 40, a residual oil fluid catalytic cracking unit (RFCC unit 50) (an example of a cracking processing unit), a first transport line 10, a molten waste plastic supply line 15X, a mixed oil transport line 15, a supply line 12X as a first feedstock oil supply line, a supply line 13 as a second feedstock oil supply line, and a second transport line 14. The processing system 100 also includes a waste plastic supply control means 25 and feedstock oil supply control means 121, 131.

(Kneader 20)
The kneader 20 prepares molten waste plastics by melting the waste plastics.
Molten waste plastic refers to solid waste plastic that has been melted and turned into liquid. Therefore, the only difference between molten waste plastic and solid waste plastic is the state of the material.
The waste plastic is melted in the kneader 20 to become molten waste plastic, and is in a molten state, a dissolved state, or a slurry.

The waste plastic supply control means 25 has a feeder 21 and a feeder controller 24. 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. A microcomputer or the like can be used as the feeder controller 24. The amount of waste plastic supplied means the amount (mass) of waste plastic supplied per unit time.
The kneader 20 is connected to a feeder 21 and a hopper 22 via a waste plastic supply line 23 .
The kneader 20 melts the waste plastics supplied from the hopper 22 via the feeder 21 to prepare molten waste plastics.
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.

(First transport line 10)
The first transportation line 10 is connected to the RFCC unit 50 and transports the feed oil to the RFCC unit 50 .
The first transportation line 10 has, in order from the upstream side, a branching point B1 where it branches into a supply line 12X and a supply line 13, and a junction C1 with the second transportation line 14.
The temperature of the raw oil in the first transport line 10 is preferably 80°C or higher and 240°C or lower, more preferably 160°C or higher and 230°C or lower, and can be controlled, for example, by a temperature control means (e.g., a heat exchanger, a heater, etc.) installed at any location in the first transport line 10.

(Supply line 12X)
The supply line 12X branches off from the branch point B1 of the first transport line 10, then branches off further at branch point B3, and supplies raw oil (corresponding to the first raw oil) to the first storage tank 60 via the junction C3 with the molten waste plastic supply line 15X.
A heat exchanger HE for controlling the temperature of the first feed oil and a feed oil supply control means 121 are provided in the supply line 12X.
The feedstock oil supply control means 121 has a control valve 122 and a controller 123. The feedstock oil supply control means 121 controls the supply amount of the first feedstock oil by transmitting a control signal from the controller 123 to the control valve 122 and controlling the operation of the control valve 122. The controller 123 can be a microcomputer or the like.

(Supply line 13)
The supply line 13 connects the first transport line 10 and the line mixer 30 , and supplies the raw material oil (corresponding to the second raw material oil) from the first transport line 10 to the line mixer 30 .
A heat exchanger HE for controlling the temperature of the second feed oil, and a feed oil supply control means 131 are provided in the supply line 13 .
The raw oil supply control means 131 has a control valve 132 and a controller 133. The operation of the raw oil supply control means 131 is similar to the operation of the raw oil supply control means 121.

(Molten waste plastic supply line 15X)
The molten waste plastic supply line 15X connects the kneader 20 and the first storage tank 60, and supplies molten waste plastic from the kneader 20 to the first storage tank 60.

(First storage tank 60)
The first storage tank 60 is equipped with a rotor 80 as an agitation means. The rotor 80 is connected to a motor (not shown). The first storage tank 60 prepares the molten waste plastic mixed oil by carrying out a first preparation step described later.
Examples of the stirring means include stirring blades such as impellers and rotor blades. Examples of the stirring blades include screw type, propeller type, paddle type, and turbine type, but the shape of the stirring blades is not particularly limited.
The stirring means is preferably a stirring blade, and the stirring blade is preferably a helical ribbon blade.
A gear pump 61 is connected to the first storage tank 60. The pump is not limited to the gear pump 61. The first storage tank 60 may supply the molten waste plastic mixed oil to the line mixer 30 by its own pressure.

(Mixed oil transport line 15)
The mixed oil transport line 15 connects the first storage tank 60 and the line mixer 30 , and supplies the molten waste plastic mixed oil prepared in the first storage tank 60 from the first storage tank 60 to the line mixer 30 .
The temperature of the molten waste plastic mixed oil in the mixed oil transport line 15 is preferably 160°C or higher and 260°C or lower, and can be controlled, for example, by a temperature control means (e.g., a heat exchanger, a heater, etc.) installed at any location in the mixed oil transport line 15.

(Line mixer 30)
The line mixer 30 includes an agitating blade 90 as an agitating means. The agitating blade 90 is connected to a motor (not shown).
The line mixer 30 prepares the mixture for decomposition treatment by carrying out the second preparation step described below. Examples of the stirring means include the stirring means exemplified in the section on the first storage tank 60.
The line mixer 30 is not particularly limited, and an in-line mixer (for example, a static mixer) may be used. The line mixer 30 may be a continuous mixer.

(Second storage tank 40)
The second storage tank 40 stores the mixture for decomposition treatment prepared in the line mixer 30. A centrifugal pump 41 is connected to the second storage tank 40. The pump is not limited to the centrifugal pump 41. The second storage tank 40 may supply the mixture for decomposition treatment to the RFCC device 50 by its own pressure.
The second storage tank 40 may also have a stirring means (for example, a rotor or the like).

(Second transport line 14)
In the case of FIG. 1 , the second transport line 14 transports the decomposition treatment mixture prepared in the line mixer 30 to the second storage tank 40, and then transports it to the junction C1 of the first transport line 10.

(RFCC device 50)
The RFCC device 50 decomposes the molten waste plastics in the mixture for decomposition treatment prepared in the line mixer 30 into liquefied petroleum gases (propane, propylene, n-butane, isobutane, butylene, etc.), and decomposes the raw oil into FG (gasoline), LCO (light cracked diesel oil), CLO (residual oil), etc.
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.

When using the processing system 100 shown in FIG. 1, the manufacturing method of the second embodiment is carried out through the following steps.

<First preparation step>
The first preparation process prepares a molten waste plastic mixed oil by mixing molten waste plastic melted in the kneader 20 with a first raw material oil supplied from a supply line 12X in a first storage tank 60 equipped with a rotor 80.
The first feedstock satisfies the above formulas (4), (5), (6) and (7). The temperature of the first feedstock is preferably in the same range as the temperature of the feedstock in the first transportation line 10.

(Melt viscosity of molten waste plastic (viscosity A))
It is preferable that the melt viscosity (viscosity A) of the molten waste plastic satisfies the following formula (Mathematical formula 10).
1.0×10 ⁶ mPa·s≦Viscosity A≦1.0×10 ⁸ mPa·s (Equation 10)
The viscosity A is the melt viscosity (mPa·s) of the molten waste plastic at 200° C.
When the melt viscosity (viscosity A) is 1.0×10 ⁶ mPa·s or more, the waste plastics can be melted without applying an excessive load in the kneader 20, making it easier to control the melting amount of the molten waste plastics.
If the melt viscosity (viscosity A) is 1.0×10 ⁸ mPa·s or less, the waste plastic can be melted by the frictional heat between the molten resins in addition to a certain degree of load on the kneader 20 .

The melting temperature of the waste plastic is preferably 175°C or higher and 260°C or lower, and more preferably 200°C or higher and 240°C or lower.
The melting temperature of the waste plastic is the set temperature of the kneader 20.

In the first preparation step, mixing in the first storage tank 60 is preferably performed under conditions of a temperature (mixing temperature) of 175°C or higher and 260°C or lower and a rotation speed of the rotor 80 of 3 rpm or higher and 1,000 rpm or lower, and more preferably under conditions of a temperature of 200°C or higher and 240°C or lower and a rotation speed of the rotor 80 of 10 rpm or higher and 500 rpm or lower.
The mixing temperature in the first storage tank 60 is the set temperature of the first storage tank 60. It is preferable that the first storage tank 60 includes a temperature detection means (e.g., a thermometer, etc.), and the mixing temperature is controlled by a temperature control means (e.g., a heat exchanger, a heater, etc.).

(Melt viscosity of molten waste plastic mixed oil (viscosity B))
The melt viscosity (viscosity B) of the molten waste plastic mixed oil prepared in the first preparation step preferably satisfies the following formula (Mathematical Formula 20), and more preferably satisfies the following formula (Mathematical Formula 21).
The measured value of the melt viscosity (viscosity B) of the molten waste plastic mixed oil is, in the case of Figure 1, a value measured using the molten waste plastic mixed oil in the mixed oil transport line 15 connected to the outlet of the first storage tank 60.
1000 mPa・s≦Viscosity B≦1 million mPa・s…(Equation 20)
1000mPa・s≦Viscosity B≦500,000mPa・s…(Equation 21)
(The viscosity B is the melt viscosity (mPa·s) at 200° C.)
When the melt viscosity (viscosity B) of the molten waste plastic mixed oil satisfies the above formula (Mathematical formula 20), the transportability of the molten waste plastic mixed oil is improved.

<Second preparation step>
In the second preparation process, the molten waste plastic mixed oil prepared in the first preparation process and the second raw material oil supplied from the supply line 13 are mixed in a line mixer 30 equipped with an agitating blade 90 to prepare a mixture for decomposition processing.
The temperature of the second feedstock is preferably in the same range as the temperature of the feedstock in the first transport line 10 .

The second preparation step is preferably carried out under conditions of a temperature (mixing temperature) of 160° C. or higher and 260° C. or lower and a rotation speed of the stirring blade 90 of 10 rpm or higher and 20,000 rpm or lower, and more preferably under conditions of a temperature of 170° C. or higher and 240° C. or lower and a rotation speed of the stirring blade 90 of 100 rpm or higher and 10,000 rpm or lower.
The mixing temperature is the set temperature of the line mixer 30. The line mixer 30 is preferably equipped with a temperature detection means (e.g., a thermometer, etc.), and the mixing temperature is preferably controlled by a temperature control means (e.g., a heat exchanger, a heater, etc.).

(Density, refractive index, kinematic viscosity, and residual ratio of filtrate of decomposition treatment mixture)
It is preferable that the decomposition treatment mixture prepared in the second preparation step has a density (15°C) that satisfies the formula (Mathematical Formula 1), a refractive index (70°C) that satisfies the formula (Mathematical Formula 2), a kinetic viscosity (200°C) that satisfies the formula (Mathematical Formula 3), and a residual ratio of the filtrate (the filtrate/the waste plastic contained in the decomposition treatment mixture) that is 0.35 or less in mass ratio.
These measured values of the mixture for decomposition treatment were measured using the mixture for decomposition treatment in the second transport line 14 connected to the outlet of the line mixer 30 in the case of FIG.

<Decomposition treatment mixture storage step>
The manufacturing method of the second embodiment includes a decomposition treatment mixture storage step of storing the decomposition treatment mixture prepared in the second preparation step in a second storage tank 40 .
The mixture for cracking treatment stored in the second storage tank 40 is transported through the second transport line 14 and merges with the raw oil transported through the first transport line 10 at the junction C1, and is supplied to the RFCC unit 50.

[Production method embodiment 2]
The manufacturing method according to the second embodiment can be carried out, for example, by using a processing system 200 shown in FIG. 2 (manufacturing method aspect 2).

<Overall composition>
The treatment system 200 shown in Fig. 2 differs from the treatment system 100 shown in Fig. 1 in that the treatment system 200 includes a supply line 11 as a first feed oil supply line, the first storage tank 60 includes a gas vent line 44, and the second storage tank 40 includes a gas vent line 43. The other points are the same as those of the treatment system 100.
That is, the treatment system 200 includes two first feed oil supply lines (supply lines 11 and 12X). In the following description, configurations different from those in the embodiment 1 of the production method will be described, and descriptions of similar configurations will be omitted.

<Supply line 11>
The supply line 11 branches off from the branch point B1 of the first transport line 10, and further branches off at a branch point B2 to supply the first raw material oil to the outlet side of the kneader 20. A raw material oil supply control means 111 is provided midway along the supply line 11.
The feedstock oil supply control means 111 includes a control valve 112 and a controller 113. The operation of the feedstock oil supply control means 111 is similar to the operation of the feedstock oil supply control means 121.

When the processing system 200 shown in FIG. 2 is used, the manufacturing method of the second embodiment is carried out through the following steps.

<First preparation step>
The first preparation process prepares a molten waste plastic mixed oil by mixing the molten waste plastic prepared in the kneader 20, the first raw material oil supplied from the supply line 11 to the outlet side of the kneader 20, and the first raw material oil supplied from the supply line 12 in the first storage tank 60.
The temperature of the first feedstock is preferably in a range similar to the temperature of the feedstock in the first transport line 10 .

(First gas release step)
The first preparation step includes a first degassing step, which is a step of discharging gas (e.g., water vapor, volatile organic compounds, etc.) generated from the molten waste plastic mixed oil from the first storage tank 60 through a degassing line 44 (an example of a degassing means).

(Second gas release process)
The decomposition treatment mixture storage step includes a second degassing step, which is a step of discharging gas (e.g., water vapor, volatile organic compounds, etc.) generated from the decomposition treatment mixture from the second storage tank 40 via a degassing line 43 (an example of a degassing means).

[Production method embodiment 3]
The manufacturing method according to the second embodiment can be carried out, for example, by using a processing system 300 shown in FIG. 3 (manufacturing method aspect 3).

<Overall composition>
The processing system 300 shown in Fig. 3 differs from the processing system 100 shown in Fig. 1 in that it includes an additional feedstock oil supply line 70X. The other points are the same as the processing system 100. In the following description, the configurations different from the embodiment 1 of the production method will be described, and the description of the similar configurations will be omitted.

<Additional feed oil supply line 70X>
The additional feedstock oil supply line 70X supplies the additional feedstock oil to the outlet side of the kneader 20. As the additional feedstock oil, a feedstock oil which is the same as or different from the first feedstock oil and the second feedstock oil can be used.
An additional raw material supply control means 171 is provided in the additional raw material supply line 70X. The additional raw material supply control means 171 has a regulation valve 172 and a controller 173. The operation of the additional raw material supply control means 171 is similar to the operation of the raw material supply control means 121.
The temperature of the additional feedstock in the additional feedstock supply line 70X is preferably in a similar range to the temperature of the feedstock in the first transport line 10.

When the processing system 300 shown in FIG. 3 is used, the manufacturing method of the second embodiment is carried out through the following steps.

<First preparation step>
The first preparation process prepares a molten waste plastic mixed oil by mixing molten waste plastic melted in the kneader 20, additional raw oil supplied from the additional raw oil supply line 70X, and first raw oil supplied from the supply line 12X in the first storage tank 60.

<Second preparation step>
The second preparation step is carried out in the same manner as in the first embodiment of the production method.

[Production Methods 4 to 7]
The treatment systems 400, 500, 600, and 700 shown in Figs. 5 to 8 are examples equipped with a specific surface area enlarging means for enlarging the specific surface area of the molten waste plastics.

The specific surface area increasing means is preferably at least one of a stretching plate, a perforated plate, a pump, and a divided supply line.
An example of the stretched plate is the stretched plate shown in Fig. 4A. The stretched plate shown in Fig. 4A has a substantially circular main body 70A and a plurality of openings 71. The openings 71 are sheet-shaped. The shape of the main body 70A is not particularly limited. The shape and number of the openings 71 are also not particularly limited.
An example of the perforated plate is the perforated plate shown in Fig. 4B. The perforated plate shown in Fig. 4B has a substantially circular main body 70B and a plurality of holes 72. The shape of the main body 70B is not particularly limited. The shape and number of the holes 72 are also not particularly limited.
The pump is not particularly limited.
The divided supply line may, for example, be one or more branch lines divided from the molten waste plastic supply line.
The specific surface area increasing means is preferably a means for increasing the specific surface area of the molten waste plastics so that the specific surface area of the molten waste plastics becomes 400 ^{m 2} /m ³ or more.

Each processing system is equipped with a specific surface area enlarging means, so that the molten waste plastics are broken down and supplied to the first storage tank 60, making it easier for the molten waste plastics to dissolve in the first raw oil in the first storage tank 60. As a result, a molten waste plastic mixed oil is obtained in which the mixability of the first raw oil and the molten waste plastics is improved.

[Production method aspect 4]
The manufacturing method according to the second embodiment can be carried out, for example, by using a processing system 400 shown in Fig. 5 (aspect 4 of the manufacturing method). The processing system 400 is an example equipped with a stretched plate or a perforated plate as a specific surface area increasing means.

<Overall composition>
The treatment system 400 shown in Fig. 5 is different from the treatment system 100 in that the molten waste plastic supply line 15X is provided with a specific surface area enlarging means 70, and the first raw material oil is directly supplied to the first storage tank 60 from the supply line 12. The other points are the same as the treatment system 100. In the following description, the configurations different from the embodiment 1 of the production method will be described, and the description of the similar configurations will be omitted.

(Means for Increasing Specific Surface Area)
For example, a stretched plate as shown in Fig. 4A or a perforated plate as shown in Fig. 4B can be suitably used as the specific surface area enlarging means 70. Fig. 4A corresponds to a cross-sectional view taken along line II in Fig. 5 when the specific surface area enlarging means 70 is a stretched plate. Fig. 4B corresponds to a cross-sectional view taken along line II in Fig. 5 when the specific surface area enlarging means 70 is a perforated plate.

When the processing system 400 shown in FIG. 5 is used, the manufacturing method of the second embodiment is carried out through the following steps.

<Specific surface area expansion process>
The molten waste plastic discharged from the kneader 20 passes through the specific surface area enlarging means 70, whereby the specific surface area is enlarged.

<First preparation step>
The first preparation process prepares molten waste plastic mixed oil by mixing molten waste plastic whose specific surface area has been expanded by the specific surface area expansion means 70 with the first raw material oil supplied from the supply line 12 in the first storage tank 60.

<Second preparation step>
The second preparation step is carried out in the same manner as in the first embodiment of the production method.

[Production method aspect 5]
The manufacturing method according to the second embodiment can be carried out, for example, by using a processing system 500 shown in Fig. 6 (aspect 5 of the manufacturing method). The processing system 500 is an example equipped with a divided supply line as the specific surface area enlarging means.

<Overall composition>
The processing system 500 shown in Fig. 6 differs from the processing system 200 shown in Fig. 2 in that the molten waste plastic supply line 15X includes a plurality of divided supply lines 73, 74, 731, 732 (an example of a specific surface area enlarging means) and that the first raw material oil is supplied directly to the first storage tank 60 from the supply line 12. The other points are the same as those of the processing system 200. In the following description, the configurations different from the embodiment 2 of the manufacturing method will be described, and the description of the similar configurations will be omitted.

(Means for Increasing Specific Surface Area)
In the case of FIG. 6, a plurality of divided supply lines 73, 74, 731, and 732 correspond to the specific surface area enlarging means.
The divided supply lines 73 and 74 are branched off from the molten waste plastic supply line 15X at a branch point B10, and the divided supply line 73 is further branched off into divided supply lines 731 and 732. The number of divided supply lines is not limited to these.

When the processing system 500 shown in FIG. 6 is used, the manufacturing method of the second embodiment is carried out through the following steps.

<Specific surface area expansion process>
The molten waste plastic discharged from the kneader 20 flows through the molten waste plastic supply line 15X and the multiple divided supply lines 73, 74, 731, 732, thereby increasing the specific surface area of the molten waste plastic.

<First preparation step>
The first preparation process prepares molten waste plastic mixed oil by mixing molten waste plastic (molten waste plastic with an expanded specific surface area) supplied from the molten waste plastic supply line 15X and multiple divided supply lines 73, 74, 731, 732 with the first raw material oil supplied from the supply line 12 in the first storage tank 60.

<Second preparation step>
The second preparation step is carried out in the same manner as in the second embodiment of the production method.

[Production Method 6]
The manufacturing method according to the second embodiment can be carried out, for example, by using a processing system 600 shown in Fig. 7 (aspect 6 of the manufacturing method). The processing system 600 is an example equipped with a pump as the specific surface area increasing means.

<Overall composition>
The treatment system 600 shown in Fig. 7 differs from the treatment system 300 shown in Fig. 3 in that it has a circulation line 91 through which a part of the molten waste plastic mixed oil circulates, the circulation line 91 is equipped with a pump 75 (an example of a specific surface area expanding means), the molten waste plastic supply line 15Y is connected to the circulation line 91, and the first raw material oil is supplied directly to the first storage tank 60 from the supply line 12. The other points are the same as those of the treatment system 300.
In the following description, configurations different from those in the third embodiment of the manufacturing method will be described, and descriptions of similar configurations will be omitted.

(Means for Increasing Specific Surface Area)
In the case of FIG. 7, the pump 75 corresponds to the specific surface area increasing means.

When using the processing system 600 shown in FIG. 7, the manufacturing method of the second embodiment is carried out through the following steps.

<Specific surface area expansion process>
The molten waste plastics flowing through the molten waste plastic supply line 15Y and a portion of the molten waste plastic mixed oil prepared in the first storage tank 60 are joined at a joining point C12. The mixture (the mixture of the molten waste plastics and the molten waste plastic mixed oil) joined at the joining point C12 passes through a pump 75, whereby the specific surface area of the molten waste plastics contained in the mixture is expanded.

<First preparation step>
The mixture containing the molten waste plastics with an increased specific surface area is supplied to the first storage tank 60 from the mixed oil supply port 102 of the circulation line 91 .
The first preparation process prepares a molten waste plastic mixed oil by mixing the mixture supplied from the mixed oil supply port 102 of the circulation line 91 with the first raw material oil supplied from the supply line 12 in the first storage tank 60.

During operation of the processing system 600, the specific surface area increasing step and the first preparation step are performed as follows.
The molten waste plastic flowing through the molten waste plastic supply line 15Y and the first raw material oil supplied from the supply line 12 and stored in the first storage tank 60 are merged at a junction C12 and then pass through a pump 75.
The specific surface area of the molten waste plastics is increased by passing through the pump 75 (specific surface area increasing step). The molten waste plastics with the increased specific surface area are supplied to the first storage tank 60 from the mixed oil supply port 102 of the circulation line 91.
In the first preparation step, molten waste plastic mixed oil is prepared by mixing the molten waste plastics supplied from the mixed oil supply port 102 of the circulation line 91 and the first raw oil supplied from the supply line 12 in the first storage tank 60. A portion of the prepared molten waste plastic mixed oil is discharged into the circulation line 91 and merges with the molten waste plastics flowing through the molten waste plastic supply line 15Y at the merging point C12.

<Second preparation step>
The second preparation step is carried out in the same manner as in the third embodiment of the production method.

[Production method embodiment 7]
The manufacturing method according to the second embodiment can be carried out, for example, by using a processing system 700 shown in Fig. 8 (aspect 7 of the manufacturing method). The processing system 700 is an example equipped with a pump as the specific surface area increasing means.

<Overall composition>
The treatment system 700 shown in Figure 8 is different from the treatment system 600 shown in Figure 7 in that the circulation line 92 is connected to the first feedstock oil supply line 12. The other points are the same as the treatment system 600.
In the following description, configurations different from those in the sixth embodiment of the manufacturing method will be described, and descriptions of similar configurations will be omitted.

When using the processing system 700 shown in FIG. 8, the manufacturing method of the second embodiment is carried out through the following steps.

<Specific surface area expansion process>
The specific surface area increasing step is carried out in the same manner as in the sixth embodiment of the production method.

<First preparation step>
The mixture (a mixture of molten waste plastics and molten waste plastic mixed oil) containing molten waste plastics with an expanded specific surface area circulates through the circulation line 92, and then merges with the first raw material oil at the junction C13 with the supply line 12 and is supplied to the first storage tank 60.
In the first preparation process, the mixture (a mixture of molten waste plastics and molten waste plastic mixed oil) is mixed with a first raw material oil in a first storage tank 60 to prepare a molten waste plastic mixed oil.

<Second preparation step>
The second preparation step is carried out in the same manner as in the sixth embodiment of the production method.

During operation of the processing system 700, the specific surface area increasing step and the first preparation step are performed as follows.
The specific surface area increasing step is similar to the specific surface area increasing step performed when the treatment system 600 is in operation.
In the first preparation step, the molten waste plastics (molten waste plastics with an expanded specific surface area) joined at the joining point C13 and the first raw oil are mixed in the first storage tank 60 to prepare a molten waste plastic mixed oil. A part of the prepared molten waste plastic mixed oil is discharged to the circulation line 92 and joined at the joining point C12 with the molten waste plastics flowing through the molten waste plastic supply line 15Y.

[One embodiment of the first storage tank]
In the first to seventh aspects of the production method, the first storage tank preferably includes a helical ribbon impeller as the stirring means.
9A and 9B are a top view and a front view of a first storage tank 60A in the case where the stirring means is a stirring blade, and the stirring blade is a helical ribbon blade. The left diagram in Fig. 9 shows a top view, and the right diagram shows a front view.
The first storage tank 60A shown in FIG. 9 includes a dissolution tank 65, an agitating blade (helical ribbon blade) 62, a shaft 63, and a pair of support rods 64.
The symbols in FIG.
· D... inner diameter of the dissolution tank · d ₀ ... impeller diameter of the impeller · d ₁ ... central cavity diameter of the impeller · d _S1 ... shaft diameter of the shaft · d _S2 ... shaft diameter of the support rod · h... height of the impeller · Dy... clearance between the dissolution tank and the impeller · TL... tangential line · L... height of the dissolution tank · w... impeller blade width

In one embodiment of the first storage tank 60A, it is preferable that the impeller width w (m) satisfies the following formulas (Number X1) and (Number X2) when the inner diameter of the dissolution tank is D (m) and the impeller diameter of the impeller is _d0 (m).
w ≧ 0.10D ... (number X1)
d ₀ ≧0.85D…(number x2)

In one embodiment of the first storage tank 60A, it is preferable that the clearance Dy (m) between the dissolution tank and the stirring blade satisfies the following formulas (Y1) and (Y2), where D (m) is the inner diameter of the dissolution tank and _d0 (m) is the stirring blade diameter of the stirring blade.
Dy=(D-d ₀ )/2...(number Y1)
Dy≦0.075D ... (number Y2)

In one embodiment of the first storage tank 60A, when the height of the dissolution tank is L (m) and the inner diameter of the dissolution tank is D (m), it is preferable that L/D satisfies the following formula (number Z).
0.8≦L/D≦1.6...Formula (number Z)

An example of the dimensions of each component that makes up the first storage tank 60A is shown in Table 3.

Explanation of Table 3: V represents the volume of the dissolution tank [m ³ ].

[One embodiment of the dissolution apparatus]
The processing system shown in Figures 5 to 8 can include any of the dissolving apparatuses shown in Figures 10 to 14. Figures 10 to 14 are schematic diagrams of an example of the dissolving apparatus. The dissolving apparatuses shown in Figures 10 to 14 will be described.

(Dissolving device 1)
The dissolution apparatus 1 shown in Fig. 10 is provided in the processing system 400 shown in Fig. 5. The reference numerals correspond to those in Fig. 5.
The dissolving device 1 includes a first storage tank 60 equipped with an agitation means 80, a molten waste plastic supply line 15X, a raw oil supply line 12, a specific surface area enlarging means 70, and a mixed oil transport line 15.

(Dissolving device 1B)
The dissolution apparatus 1B shown in Fig. 11 is provided in the processing system 500 shown in Fig. 6. The reference numerals correspond to those in Fig. 6.
The melting apparatus 1B differs from the melting apparatus 1 shown in Fig. 10 in that the specific surface area enlarging means are divided supply lines 73, 74, 731, and 732. The other points are the same as those of the melting apparatus 1.

(Dissolving device 1C)
The dissolution apparatus 1C shown in Fig. 12 is provided in the processing system 600 shown in Fig. 7. The reference numerals correspond to those in Fig. 7.
The dissolving apparatus 1C comprises a first storage tank 60 equipped with an agitation means 80, a molten waste plastic supply line 15Y, a raw oil supply line 12, a circulation line 91 for circulating a portion of the molten waste plastic mixed oil, a mixed oil transport line 15, and a pump 75 arranged on the circulation line 91 as a specific surface area expansion means for expanding the specific surface area of the molten waste plastic.
The first storage tank 60 also includes a plurality of discharge ports 101A, 101B for discharging the molten waste plastic mixed oil obtained in the first storage tank 60, and a mixed oil supply port 102 for supplying a portion of the molten waste plastic mixed oil back into the first storage tank 60 via the circulation line 91. The circulation line 91 connects the discharge port 101B of the first storage tank 60 to the mixed oil supply port 102.

(Dissolving device 1D)
The dissolution apparatus 1D shown in Fig. 13 is provided in the processing system 700 shown in Fig. 8. The reference numerals correspond to those in Fig. 8.
The melting apparatus 1D shown in Fig. 13 differs from the melting apparatus 1C shown in Fig. 12 in that the downstream side of the circulation line 92 is connected to the raw oil supply line 12. The other points are the same as those of the melting apparatus 1C.

(Dissolving device 1A)
The melting apparatus 1A shown in Fig. 14 is different from the melting apparatus 1 shown in Fig. 10 in that the raw oil supply line 12X is not directly connected to the first storage tank 60, but is connected to the molten waste plastic supply line 15X at the junction C3. The other points are the same as those of the melting apparatus 1.

The processing system 400 shown in FIG. 5 may include a melting apparatus 1B shown in FIG. 11, a melting apparatus 1C shown in FIG. 12, or a melting apparatus 1D shown in FIG.
The processing system 500 shown in FIG. 6 may include the melting apparatus 1 shown in FIG. 10, the melting apparatus 1C shown in FIG. 12, or the melting apparatus 1D shown in FIG. 13, instead of the melting apparatus 1B.
The processing system 600 shown in FIG. 7 may include the melting apparatus 1 shown in FIG. 10, the melting apparatus 1B shown in FIG. 11, or the melting apparatus 1D shown in FIG. 13, instead of the melting apparatus 1C.
The processing system 700 shown in FIG. 8 may include the melting apparatus 1 shown in FIG. 10, the melting apparatus 1B shown in FIG. 11, or the melting apparatus 1C shown in FIG. 12, instead of the melting apparatus 1D.

Moreover, the processing systems 400, 500, 600, and 700 shown in FIGS. 5 to 8 may each include a melting apparatus 1A shown in FIG. 14 in place of the melting apparatus included therein.
In these embodiments, as shown in FIG. 14, the raw oil supply line 12X is not directly connected to the first storage tank 60, but is connected to any point of the molten waste plastic supply line 15X.

[Other aspects of the manufacturing method]
In the first to seventh aspects of the production method, the molten waste plastic mixed oil may be prepared using two or more first storage tanks 60. The arrangement of the first storage tanks 60 is not particularly limited. The two or more first storage tanks 60 may be the same or different from each other.
In the first to seventh aspects of the production method, the mixture for decomposition treatment may be prepared using two or more line mixers 30. The arrangement of the line mixers 30 is not particularly limited. The two or more line mixers 30 may be the same or different from each other.
In the first to seventh aspects of the production method, the mixture for decomposition treatment prepared in the line mixer 30 may be circulated to at least one of the first storage tank 60 and the line mixer 30 via a circulation line.
In the first to seventh aspects of the production method, additional feed oil may be supplied to the line mixer 30 .
In the manufacturing method of the first to seventh embodiments, the molten waste plastic may be prepared using two or more kneaders 20. The arrangement of the kneaders 20 is not particularly limited. The two or more kneaders 20 may be the same or different from each other.

In the first to seventh aspects of the production method, the mixture for decomposition treatment prepared in the line mixer 30 may be supplied to the RFCC device without being stored in the second storage tank.
In the manufacturing method embodiments 1 to 7, the mixture for decomposition treatment prepared in the line mixer 30 may be directly supplied to the RFCC device through the second transport line.
In the first to seventh aspects of the production method, a known mixing device may be used in place of the line mixer 30.
In the first to seventh embodiments of the production method, the RFCC unit 50 may be replaced with, for example, a known cracking treatment unit used in the field of petroleum refining.

The mixture for decomposition treatment in the first embodiment does not have to be produced by the above-mentioned aspects 1 to 7 of the production method as long as it satisfies the formulas (1) to (3) and the residual ratio of the filtered matter is 0.35 or less in mass ratio. For example, the mixture for decomposition treatment may be produced by heating solid waste plastic and raw oil having specific properties in a first storage tank and mixing the waste plastic with the raw oil while melting it.

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

Example 1
Using polyethylene as waste plastic, waste plastic (4 g) and DSRC (196 g) as feedstock oil were introduced into a homogenizer, and the waste plastic was mixed with the DSRC while melting under the following conditions to prepare a mixture for decomposition treatment. The feedstock oil having the properties shown in Table 1 above was used as the DSRC.
(Melt mixing conditions)
Homogenizer: Tokushu Kika Co., Ltd. T.K. Homo Disper 2.5 type Blade: Turbine blade Temperature: 200℃
・Rotation speed: 900 rpm

Example 2
A mixture for cracking treatment was prepared in the same manner as in Example 1, except that the feed oil was changed to HCO. A feed oil having the properties shown in Table 1 above was used as HCO.

Example 3
A mixture for cracking treatment was prepared in the same manner as in Example 1, except that the feedstock oil was changed to HG-500. A feedstock oil having the properties shown in Table 2 above was used as HG-500.

Comparative Example 1
A mixture for cracking treatment was prepared in the same manner as in Example 1, except that the feed oil was changed to benzyl alcohol.
The properties of benzyl alcohol are as follows:
・Density (15℃): 1.049g/ ^cm3
Refractive index (70°C): 1.518
・Kinematic viscosity (75°C): 1.52mm ² /s
・Molecular weight: 108g/mol

〔evaluation〕
The properties of the decomposition mixture obtained in each example were measured, and the results are shown in Table 4.

(Density, Refractive Index and Kinematic Viscosity)
The density (15° C.), refractive index (70° C.) and kinematic viscosity (200° C.) of the decomposition treatment mixture were measured by the methods described above.

(Remaining ratio of filtered matter)
200 g of the mixture for decomposition treatment was passed through a 40 mesh filter under its own weight under conditions of room temperature and normal pressure (25° C., 1 atm).
The residual ratio of the filtrate to the waste plastics contained in the mixture for decomposition treatment (filtrate/waste plastics contained in the mixture for decomposition treatment) (mass ratio) was calculated by the method described above.
In this evaluation, the mass of waste plastic contained in the mixture for decomposition treatment is 4 g.

The decomposition mixtures of Examples 1 to 3 have densities (15°C), refractive indices (70°C), and kinetic viscosities (200°C) that satisfy the above-mentioned formulas (1) to (3), respectively. The decomposition mixtures of Examples 1 to 3 having such properties exhibited significantly low residual ratios of the filtered matter (all of which were 0.35 or less).
On the other hand, the mixture for decomposition treatment in Comparative Example 1 had a kinetic viscosity that did not satisfy the above formula (Mathematical formula 3), and therefore exhibited a high residual ratio of the filtrate (1.00).
From the above results, it can be seen that the molten waste plastics and the raw material oil are sufficiently mixed in the mixtures for decomposition treatment of Examples 1 to 3. Therefore, by decomposing the mixtures for decomposition treatment of Examples 1 to 3 in the decomposition treatment device, the decomposition ability of the waste plastics can be improved.

The mixture for decomposing waste plastics of the present invention can be used industrially because it can increase the utilization efficiency of chemical recycling of waste plastics.

1, 1A, 1B, 1C, 1D... Melting device, 10... First transport line, 11, 12, 12X... Supply line (first raw oil supply line), 13... Supply line (second raw oil supply line), 14... Second transport line, 15X, 15Y... Molten waste plastic supply line, 15... Mixed oil transport line, 20... Kneader, 21... Feeder, 22... Hopper, 23... Waste plastic supply line, 24... Feeder controller, 25... Waste plastic supply control means, 30... Line mixer, 40... Second storage tank, 41... Centrifugal pump, 43, 44... Gas venting line, 50... RFCC device, 60, 60A... First storage tank, 6 1...gear pump, 62...mixing blade, 63...shaft, 64...pair of support rods, 65...dissolving tank, 70...specific surface area enlarging means, 70A, 70B...main body, 71...opening, 72...hole, 73, 74, 731, 732...divided supply lines, 70X...additional feedstock oil supply line, 75...pump, 80...rotor, 90...mixing blade, 91, 92...circulation line, 100, 200, 300, 400, 500, 600, 700...treatment system, 102...mixed oil supply port, 111, 121, 131, 171...feedstock oil supply control means, 112, 122, 132, 172...control valve, 113, 123, 133, 173...controller, HG...heat exchanger.

Claims (7)

A mixture for decomposing waste plastics in a decomposition treatment device,
The mixture for waste plastic decomposition treatment is
The waste plastic melting process includes melted waste plastic and raw material oil,
The following formulas (1), (2) and (3) are satisfied,
When the mixture for waste plastic decomposition processing is passed through a 40 mesh filter, the ratio of the residue to the waste plastic contained in the mixture for waste plastic decomposition processing (the residue/the waste plastic contained in the mixture for waste plastic decomposition processing) is 0.35 or less by mass ratio.
Mixture for decomposing waste plastics.
0.850g/cm ³ ≦Density (15°C) ≦1.150g/cm ³ ... (Math. 1)
1.400≦refractive index (70° C.)≦1.650 (Equation 2)
4.0mm ² /s≦Kinematic viscosity (200°C)≦20.0mm ² /s (Math. 3) The mixture for waste plastic decomposition processing according to claim 1,
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, mineral oil, heavy gas oil, desulfurized heavy gas oil, desulfurized vacuum residual oil, and deasphalted oil.
Mixture for decomposing waste plastics. The mixture for waste plastic decomposition treatment according to claim 1 or 2,
The waste plastic includes at least one of polyethylene-derived waste plastic and polypropylene-derived waste plastic,
Mixture for decomposing waste plastics. A method for producing a mixture for decomposing waste plastics in a decomposition treatment device, comprising:
A first preparation step of preparing a molten waste plastic mixed oil by mixing a molten waste plastic, which is a melted product of the waste plastic, with a first raw material oil;
A second preparation step of preparing a mixture for waste plastic decomposition treatment by mixing the molten waste plastic mixed oil prepared in the first preparation step with a second raw material oil,
The first feedstock and the second feedstock satisfy the following formulas (4), (5), (6), and (7), respectively:
When the mixture for waste plastic decomposition treatment prepared in the second preparation step is passed through a 40 mesh filter, the ratio of the residue to the waste plastic contained in the mixture for waste plastic decomposition treatment (the residue/the waste plastic contained in the mixture for waste plastic decomposition treatment) is 0.35 or less in mass ratio;
The first feedstock and the second feedstock are the same or different from each other;
A method for manufacturing a mixture for decomposing waste plastics.
0.850g/cm ³ ≦Density (15°C) ≦1.150g/cm ³ ... (Math. 4)
1.400≦refractive index (70° C.)≦1.650 (Equation 5)
3.0mm ² /s≦Kinematic viscosity (75°C)≦55.0mm ² /s (Math. 6)
240g/mol≦molecular weight≦1000g/mol…(Math. 7) In the method for producing a mixture for waste plastic decomposition treatment according to claim 4,
The first feedstock and the second feedstock each have a hydrogen bond term (δh) represented by the Hansen solubility parameters of 1.5 or less and a dipole-dipole term (δp) represented by the Hansen solubility parameters of 4.0 or less.
A method for manufacturing a mixture for decomposing waste plastics. In the method for producing a mixture for waste plastic decomposition treatment according to claim 4 or 5,
The first feedstock and the second feedstock are each 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, mineral oil, heavy gas oil, desulfurized heavy gas oil, desulfurized vacuum residual oil, and deasphalted oil.
A method for manufacturing a mixture for decomposing waste plastics. In the method for producing a mixture for waste plastic decomposition processing according to any one of claims 4 to 6,
The waste plastic includes at least one of polyethylene-derived waste plastic and polypropylene-derived waste plastic,
A method for manufacturing a mixture for decomposing waste plastics.