Dissolving device, waste plastic decomposition device, and method for producing melted waste plastic mixed oil

Abstract

To provide a melting apparatus capable of improving solubility of molten waste plastic in a raw oil.SOLUTION: A melting device 1 for melting molten waste plastic into a raw oil to obtain molten waste plastic mixed oil comprises: a melting tank 60 that is equipped with stirring means 80; one or more molten waste plastic supply lines 15X that supply the molten waste plastic to the melting tank 60; one or more raw oil supply lines 12 that supply the raw oil to the melting tank 60; and specific surface area enlarging means 70 that is arranged in the molten waste plastic supply lines 15X and expands a specific surface area of the molten waste plastic. The raw oil supply lines 12 are connected to at least one of the melting tank 60 and the molten waste plastic supply lines 15X.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a melting device, a waste plastic decomposition device, and a method for producing a melted waste plastic mixed oil. [Background technology]

[0002] The low rate of effective utilization of waste plastics and environmental pollution caused by marine plastic waste have become global issues. Chemical recycling is one method for recycling waste plastics, and various chemical recycling technologies have been studied.

[0003] For example, Patent Document 1 discloses a method comprising melting a plastic material (1) to form a plastic melt, degassing the plastic melt, and then sending the 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 that of the plastic melt.

[0004] 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. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2014-518906 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-294251 Summary of the Invention [Problem to be solved by the invention]

[0006] In response to the recent demand for more effective utilization of waste plastics, decomposition treatment equipment such as FCC units are required to further improve the decomposition ability of waste plastics. To achieve this, it is necessary to improve the solubility of molten waste plastics in solvents (e.g., feedstock oil). Patent Document 1 describes adding a solvent to a plastic melt to reduce the viscosity of the plastic melt solution. However, since the plastic melt solution in Patent Document 1 is obtained by simply adding a solvent to the plastic melt in a supply line, the solubility of the plastic melt in the solvent is likely to be insufficient. 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-value-added gasoline, etc. However, Patent Document 2 does not pay any attention to improving the solubility of the hydrocarbon polymer in the hydrocarbon oil.

[0007] The present invention aims to provide a melting device that can improve the solubility of molten waste plastics in raw oil, a waste plastic decomposition device equipped with the melting device, and a method for producing molten waste plastic mixed oil. [Means for solving the problem]

[0008] According to one aspect of the present invention, there is provided a dissolving apparatus for dissolving molten waste plastics in raw oil to obtain a molten waste plastic mixed oil, the dissolving apparatus comprising: a dissolving tank equipped with a stirring means; one or more molten waste plastic supply lines for supplying the molten waste plastics to the dissolving tank; one or more raw oil supply lines for supplying the raw oil to the dissolving tank; and a specific surface area expansion means arranged on the molten waste plastic supply line for expanding the specific surface area of ​​the molten waste plastic, wherein the raw oil supply line is connected to at least one of the dissolving tank and the molten waste plastic supply line.

[0009] According to one aspect of the present invention, there is provided a melting apparatus for dissolving molten waste plastics in raw oil to obtain a molten waste plastic mixed oil, the melting apparatus comprising: a melting tank equipped with a stirring means; one or more molten waste plastic supply lines for supplying the molten waste plastics to the melting tank; one or more raw oil supply lines for supplying the raw oil to the melting tank; a plurality of outlets for discharging the molten waste plastic mixed oil obtained in the melting tank from the melting tank; a circulation line connected to one of the plurality of outlets for circulating a portion of the molten waste plastic mixed oil; and a specific surface area expansion means arranged on the circulation line for expanding the specific surface area of ​​the molten waste plastics, wherein the raw oil supply line is connected to at least one of the melting tank and the molten waste plastic supply line, and at least one of the molten waste plastic supply lines is connected to the circulation line.

[0010] In the dissolving apparatus according to one aspect of the present invention, the circulation line is preferably connected to a feedstock oil supply line.

[0011] In one embodiment of the melting apparatus of the present invention, the melting tank is provided with a mixed oil supply port through which the molten waste plastic mixed oil circulating through the circulation line is supplied, and it is preferable that the circulation line connects the mixed oil supply port to one of the multiple discharge ports.

[0012] In the dissolution apparatus according to one aspect of the present invention, the specific surface area increasing means is preferably at least one of a stretching means, a perforated plate, a pump, and a divided supply line.

[0013] In the dissolving apparatus according to one aspect of the present invention, the stirring means is a stirring blade, and the stirring blade is preferably a helical ribbon blade.

[0014] In the dissolution apparatus according to one aspect of the present invention, it is preferable that the blade width w (m) of the impeller satisfies the following formulas (X1) and (X2), where D (m) is the inner diameter of the dissolution tank and d0 (m) is the impeller diameter of the impeller. w≧0.10D …(number X1) d0≧0.85D …(number x2)

[0015] In the dissolution apparatus according to one aspect of the present invention, 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-d0) / 2 ... (number Y1) Dy≦0.075D …(number Y2)

[0016] In the dissolution apparatus according to one aspect of the present invention, 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)

[0017] In the melting apparatus according to one aspect of the present invention, it is preferable to further include a temperature control means for controlling the temperature of the melting tank.

[0018] In the melting apparatus according to one aspect of the present invention, the waste plastic before melting is preferably waste plastic containing at least one of polyethylene-derived waste plastic and polypropylene-derived waste plastic.

[0019] According to one aspect of the present invention, there is provided a waste plastic decomposition device including a decomposition treatment device that decomposes waste plastic.

[0020] In the waste plastic decomposition apparatus according to one aspect of the present invention, the decomposition treatment device is preferably a fluid catalytic cracking device.

[0021] According to one aspect of the present invention, there is provided a method for producing molten waste plastic mixed oil, in which molten waste plastic is dissolved in raw oil to produce molten waste plastic mixed oil, the method comprising the steps of: expanding the specific surface area of ​​the molten waste plastic using a specific surface area expansion means in one or more molten waste plastic supply lines that supply the molten waste plastic; and mixing the molten waste plastic with the expanded specific surface area with the raw oil in a dissolving tank equipped with a stirring means.

[0022] According to one aspect of the present invention, there is provided a method for producing molten waste plastic mixed oil, which comprises the steps of: mixing the molten waste plastic with the raw oil in a dissolving tank equipped with a stirring means; increasing the specific surface area of ​​the molten waste plastic obtained in the mixing step using a specific surface area enlarging means in a circulation line in which a portion of the molten waste plastic mixed oil discharged from the dissolving tank circulates; and supplying the molten waste plastic mixed oil containing the molten waste plastic with the enlarged specific surface area back to the dissolving tank.

[0023] In the method for producing a mixed oil of molten waste plastics according to one embodiment of the present invention, the specific surface area increasing means is preferably at least one of a stretching means, a perforated plate, a pump, and a divided supply line.

[0024] In one embodiment of the present invention, in the method for producing molten waste plastic mixed oil, the stirring means is a rotor, and the mixing process is preferably carried out at normal pressure under conditions where the viscosity of the molten waste plastic mixed oil produced satisfies the following formula (Equation 1), the temperature satisfies the following formula (Equation 2), the rotation speed of the rotor satisfies the formula (Equation 3), and the residence time of the molten waste plastic and the raw material oil in the dissolution tank satisfies the following formula (Equation 4). Viscosity of melted waste plastic mixed oil ≦5.0×10 6 mPa·s …(Equation 1) 200℃≦Temperature≦250℃…(Number 2) 3 rpm ≦ rotation speed ≦ 1,000 rpm … (Number 3) Residence time ≧ 5 minutes or more ... (Number 4)

[0025] In one embodiment of the present invention, the method for producing molten waste plastic mixed oil is preferably used to produce a mixture for waste plastic decomposition treatment for decomposing waste plastics in a decomposition treatment device.

[0026] In the method for producing a mixed oil of molten waste plastics according to one aspect of the present invention, the cracking treatment device is preferably a fluid catalytic cracking device.

[0027] In one embodiment of the present invention, in the method for producing molten waste plastic mixed oil, the waste plastic before melting is preferably waste plastic containing at least one of polyethylene-derived waste plastic and polypropylene-derived waste plastic. [Effects of the Invention]

[0028] According to one aspect of the present invention, it is possible to provide a dissolving device that can improve the solubility of molten waste plastics in raw oil, a waste plastic decomposition device equipped with the dissolving device, and a method for producing molten waste plastic mixed oil. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a schematic diagram of an example of a melting apparatus according to a first embodiment. [Figure 2A] FIG. 3 is a cross-sectional view of a stretched plate when the specific surface area enlarging means is a stretched plate. [Figure 2B] FIG. 4 is a cross-sectional view of a perforated plate when the specific surface area enlarging means is a perforated plate. [Figure 3] FIG. 10 is a schematic view of an example of a melting apparatus according to a second embodiment. [Figure 4] FIG. 10 is a schematic view of an example of a dissolving apparatus according to a third embodiment. [Figure 5] FIG. 10 is a schematic view of an example of a dissolving apparatus according to a fourth embodiment. [Figure 6] FIG. 10 is a schematic view of an example of a dissolving apparatus according to a fifth embodiment. [Figure 7] 3A and 3B are a top view and a front view of an example of a melting tank provided in the melting apparatus. [Figure 8] 1 is a schematic diagram of an example of a processing system including a dissolution apparatus according to a first embodiment. [Figure 9] FIG. 10 is a schematic diagram of another example of a processing system including a dissolution apparatus according to the second embodiment. [Figure 10] FIG. 10 is a schematic diagram of an example of a processing system including a dissolution apparatus according to a third embodiment. [Figure 11] FIG. 10 is a schematic diagram of an example of a processing system including a dissolution apparatus according to a fourth embodiment. [Figure 12] FIG. 11 is a schematic diagram of an example of a processing system including a dissolution apparatus according to a fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0030] In this specification, a numerical range expressed using "to" means a range that includes the number written before "to" as the lower limit and the number written after "to" as the upper limit.

[0031] [First embodiment] The dissolving apparatus of this embodiment is a dissolving apparatus for dissolving molten waste plastics in raw oil to obtain a molten waste plastic mixed oil, and includes a dissolving tank equipped with a stirring means, one or more molten waste plastic supply lines for supplying the molten waste plastics to the dissolving tank, one or more raw oil supply lines for supplying the raw oil to the dissolving tank, and a specific surface area expanding means arranged on the molten waste plastic supply lines for expanding the specific surface area of ​​the molten waste plastics. The raw oil supply line is connected to at least one of the dissolving tank and the molten waste plastic supply line.

[0032] The melting device of this embodiment is equipped with a specific surface area expanding means in the supply line of molten waste plastics, which expands the specific surface area of ​​the molten waste plastics, so that the molten waste plastics can be broken down into smaller pieces and fed to the melting tank. As a result, a molten waste plastic mixed oil in which the molten waste plastics are well dissolved in the raw oil is obtained. According to this embodiment, a melting device that can improve the solubility of molten waste plastics in raw oil is realized.

[0033] In the dissolution apparatus of this embodiment, 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. 2A. An example of the perforated plate is the perforated plate shown in Fig. 2B. Details will be described later. The pump is not particularly limited, but is preferably a gear pump. The divided supply line may be, for example, one or more branch lines divided from the molten waste plastic supply line. The specific surface area expansion method is to increase the specific surface area of ​​molten waste plastic to 400m 2 / m 3 As described above, it is preferable that the specific surface area of ​​the molten waste plastic be increased.

[0034] The melting apparatus of the first embodiment will be described with reference to the drawings.

[0035] <Overall structure> FIG. 1 is a schematic diagram of an example of a melting apparatus according to the first embodiment. The dissolving apparatus 1 shown in Figure 1 comprises a dissolving tank 60 equipped with a stirring means 80, a molten waste plastic supply line 15X that supplies molten waste plastic to the dissolving tank 60, a raw material oil supply line 12 that supplies raw material oil to the dissolving tank 60, a specific surface area expansion means 70 that expands the specific surface area of ​​the molten waste plastic, a mixed oil transport line 15 that discharges the molten waste plastic mixed oil obtained in the dissolving tank 60, and a temperature control means (not shown) that controls the temperature of the dissolving tank 60. The specific surface area increasing means 70 is disposed on the molten waste plastic supply line 15X. The raw oil supply line 12 and the molten waste plastic supply line 15X are each connected to a dissolution tank 60.

[0036] (dissolving tank) The dissolution tank 60 is equipped with a stirring means 80 . Examples of the stirring means 80 include stirring blades such as impellers and rotors. Examples of the stirring blades include screw-type, propeller-type, paddle-type, and turbine-type. The shape of the stirring blade is not particularly limited. The stirring means is preferably a stirring blade, and the stirring blade is preferably a helical ribbon blade.

[0037] (Means for increasing specific surface area) In the case of FIG. 1, for example, a stretched plate shown in FIG. 2A and a perforated plate shown in FIG. 2B can be suitably used as the specific surface area increasing means 70. 2A corresponds to a cross-sectional view taken along line II in FIG. 1 when the specific surface area enlarging means 70 is a stretched plate. The stretched plate shown in FIG. 2A has a substantially circular main body 70A and a plurality of openings 71. The openings 71 are opened in a sheet-like shape. The shape of the main body 70A is not particularly limited. The shape and number of the openings 71 are also not particularly limited. 2B corresponds to a cross-sectional view taken along line II in FIG. 1 when the specific surface area enlarging means 70 is a perforated plate. The perforated plate shown in FIG. 2B 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.

[0038] The molten waste plastic flowing through the molten waste plastic supply line 15X passes through the specific surface area increasing means 70, whereby the specific surface area is increased.

[0039] Second Embodiment The melting apparatus of the second embodiment will be described with reference to the drawings.

[0040] <Overall structure> 3 is a schematic diagram of an example of a melting apparatus according to a second embodiment, which is one aspect of the melting apparatus according to the first embodiment. The melting apparatus 1A shown in Figure 3 differs from the melting apparatus 1 shown in Figure 1 in that the raw material oil supply line 12X is connected to the melting waste plastic supply line 15X. Other points are the same as those of the melting apparatus 1. In the following description, only the configurations different from those in the first embodiment will be described, and descriptions of the same configurations will be omitted. In the case of Figure 3, the molten waste plastics flowing through the molten waste plastic supply line 15X and the raw oil flowing through the raw oil supply line 12X are mixed at the confluence C3 to form a mixture (a mixture of molten waste plastics and raw oil). The mixture passes through the specific surface area increasing means 70 and is supplied to the dissolution tank 60.

[0041] Third Embodiment A melting apparatus according to a third embodiment will be described with reference to the drawings.

[0042] <Overall structure> 4 is a schematic diagram of an example of the melting apparatus according to the third embodiment, which is one aspect of the melting apparatus according to the first embodiment. The melting apparatus 1B shown in Fig. 4 differs from the melting apparatus 1 shown in Fig. 1 in that the specific surface area increasing means is a divided supply line. In the following description, only the configurations different from those in the first embodiment will be described, and descriptions of the same configurations will be omitted.

[0043] (Means for increasing specific surface area) In the case of FIG. 4, the specific surface area increasing means is a plurality of divided supply lines 73, 74, 731, and 732 divided from the molten waste plastic supply line 15X. The divided supply lines 73 and 74 branch off from the molten waste plastic supply line 15X at a branch point B10, and the divided supply line 73 further branches off into divided supply lines 731 and 732. The number of divided supply lines and the division points are not limited to these. The molten waste plastic flowing through the molten waste plastic supply line 15X is divided at a branch point B10 into the molten waste plastic supply line 15X and a plurality of divided supply lines 73, 74, 731, 732, and supplied to the dissolution tank 60. The specific surface area of ​​the molten waste plastic increases as it flows through a plurality of supply lines (the molten waste plastic supply line 15X and the plurality of divided supply lines 73, 74, 731, 732).

[0044] [Fourth embodiment] The fourth embodiment of the dissolving device is a dissolving device for dissolving molten waste plastics in raw oil to obtain molten waste plastic mixed oil, and is equipped with a dissolving tank equipped with a stirring means, one or more molten waste plastic supply lines for supplying the molten waste plastics to the dissolving tank, one or more raw oil supply lines for supplying the raw oil to the dissolving tank, a plurality of discharge outlets for discharging the molten waste plastic mixed oil obtained in the dissolving tank from the dissolving tank, a circulation line connected to one of the plurality of discharge outlets for circulating a portion of the molten waste plastic mixed oil, and a specific surface area expansion means arranged on the circulation line for expanding the specific surface area of ​​the molten waste plastics. The raw oil supply line is connected to at least one of the dissolving tank and the molten waste plastic supply line. At least one of the molten waste plastic supply lines is connected to the circulation line.

[0045] The melting device of the fourth embodiment has a specific surface area expanding means in the circulation line through which the molten waste plastic mixed oil circulates, which allows the molten waste plastic to be broken down into smaller pieces and fed to the melting tank. As a result, a molten waste plastic mixed oil in which the molten waste plastic is well dissolved in the raw material oil is obtained. According to the fourth embodiment, a melting device that can improve the solubility of molten waste plastics in raw oil is realized.

[0046] A melting apparatus according to a fourth embodiment will be described with reference to the drawings.

[0047] <Overall structure> FIG. 5 is a schematic diagram of an example of a melting apparatus according to the fourth embodiment. The dissolving apparatus 1C shown in Figure 5 comprises a dissolving tank 60 equipped with a stirring means 80, a molten waste plastic supply line 15Y that supplies molten waste plastic to the dissolving tank 60, a raw material oil supply line 12 that supplies raw material oil to the dissolving tank 60, a circulation line 91 that circulates a portion of the molten waste plastic mixed oil, a mixed oil transport line 15 that discharges the molten waste plastic mixed oil, and a pump 75 arranged on the circulation line 91 as a specific surface area expansion means that expands the specific surface area of ​​the molten waste plastic. The feedstock oil supply line 12 is connected to a dissolution tank 60 . The dissolving tank 60 is equipped with a plurality of discharge ports 101A, 101B for discharging the molten waste plastic mixed oil obtained in the dissolving tank 60, and a mixed oil supply port 102 for supplying a portion of the molten waste plastic mixed oil back into the dissolving tank 60 via a circulation line 91. The circulation line 91 connects the discharge port 101B of the dissolution tank 60 to the mixed oil supply port 102.

[0048] (dissolving tank) The dissolution tank 60 is equipped with a stirring means 80 . The stirring means 80 can be the stirring means described in the first embodiment.

[0049] (Means for increasing specific surface area) The specific surface area increasing means is a pump 75 . 5, the molten waste plastics flowing through the molten waste plastic supply line 15Y and the molten waste plastic mixed oil discharged from the outlet 101B of the dissolving tank 60 are mixed at the confluence C12 to form a mixture (a mixture of molten waste plastics and molten waste plastic mixed oil). After passing through the pump 75, the mixture flows through the circulation line 91 and is supplied to the dissolving tank 60 from the mixed oil supply port 102. The specific surface area of ​​the molten waste plastic contained in the mixture increases as it flows through the pump 75 .

[0050] Fifth Embodiment A melting apparatus according to a fifth embodiment will be described with reference to the drawings.

[0051] <Overall structure> 6 is a schematic diagram of an example of the melting apparatus according to the fifth embodiment, which is one aspect of the melting apparatus according to the fourth embodiment. The dissolving apparatus 1D shown in Figure 6 differs from the dissolving apparatus 1C shown in Figure 5 in that the downstream side of the circulation line 92 is connected to the raw oil supply line 12. In other respects, it is the same as the dissolving apparatus 1C. In the following description, only the configurations different from those of the fourth embodiment will be described, and descriptions of the same configurations will be omitted.

[0052] (Means for increasing specific surface area) The specific surface area increasing means is a pump 75 . 6, the molten waste plastics flowing through the molten waste plastic supply line 15Y and the molten waste plastic mixed oil discharged from the outlet 101B of the dissolving tank 60 are mixed at the confluence C12 to form a mixture (a mixture of molten waste plastics and molten waste plastic mixed oil). After passing through the pump 75, the mixture flows through the circulation line 92, and is combined with the raw material oil at the confluence C13 with the raw material oil supply line 12 to be supplied to the dissolving tank 60.

[0053] [Example of a dissolution tank] 7 shows a top view and a front view of an example of a melting tank provided in the melting apparatus. The melting apparatuses of the first to fifth embodiments preferably include a melting tank 60A shown in FIG. 7 shows a top view and a front view of a dissolution tank in which the stirring means is a stirring blade, and the stirring blade is a helical ribbon blade. The left side of FIG. 7 shows a top view, and the right side shows a front view. Dissolution tank 60A includes dissolution tank body 65, stirring blades (helical ribbon blades) 62, central shaft 63, and a pair of support shafts 64. The symbols in Figure 7 represent the following: D: Inner diameter of dissolution tank ·d0...Agitator blade diameter ·d1...Central cavity diameter of stirring impeller ·d S1 …Shaft diameter ·d S2 …Shaft diameter of support rod ·h: Height of the stirring blade Dy: Clearance between the dissolution tank and the stirring blade TL: Tangential line L: Height of dissolution tank ·w…Wing width of stirring blade

[0054] In one embodiment of the dissolution tank 60A, the blade width w (m) of the impeller preferably satisfies the following formulas (X1) and (X2), where D (m) is the inner diameter of the dissolution tank and d0 (m) is the diameter of the impeller. w≧0.10D …(number X1) d0:≧0.85D …(number x2)

[0055] In one embodiment of the dissolution tank 60A, the clearance Dy (m) between the dissolution tank and the stirring blade preferably 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-d0) / 2 ... (number Y1) Dy≦0.075D …(number Y2)

[0056] In one embodiment of the dissolution tank 60A, when the height of the dissolution tank is L (m) and the inner diameter of the dissolution tank is D (m), L / D preferably satisfies the following formula (number Z). 0.8≦L / D≦1.6…Formula (number Z)

[0057] Table 1 shows an example of the dimensions of each member constituting the dissolution tank 60A.

[0058] [Table 1]

[0059] Explanation of Table 1 V is the volume of the dissolution vessel [m 3 ].

[0060] Sixth Embodiment The waste plastic decomposition device of the sixth embodiment includes the melting device of any one of the first to fifth embodiments, and a decomposition treatment device that decomposes waste plastic. According to the waste plastic decomposition device of the sixth embodiment, since it is provided with a dissolving device that can improve the solubility of molten waste plastic in raw oil, it is possible to improve the decomposition property of waste plastic.

[0061] <Decomposition treatment device> Examples of cracking treatment units include fluid catalytic cracking units (FCC units), residual fluid catalytic cracking units (RFCC units) (one embodiment of FCC units), and hydrocracking units. From the viewpoint of improving the decomposability of waste plastics, the cracking treatment device is preferably a fluid catalytic cracking device (FCC device) or a residual catalytic cracking device (RFCC device). More preferably, the cracking treatment unit is a fluid catalytic cracking unit.

[0062] The RFCC unit and 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 in a fluidized state within this system. The catalyst used is usually a catalyst containing synthetic zeolite, and the process may be any of the processes developed by UOP, IFP, etc. The catalysts and operating conditions used in the RFCC unit and FCC unit are not particularly limited and can be set appropriately.

[0063] An example of the waste plastic decomposition device of the sixth embodiment is a waste plastic decomposition device including a dissolving device and an RFCC device 50 shown in any one of FIGS. 8 to 12, which will be described later.

[0064] Seventh Embodiment The seventh embodiment of the method for producing molten waste plastic mixed oil (hereinafter also referred to as the seventh embodiment of the method for producing molten waste plastic mixed oil) is a method for producing molten waste plastic mixed oil by dissolving molten waste plastic in raw material oil, In one or more molten waste plastic supply lines for supplying the molten waste plastic, a step of expanding the specific surface area of ​​the molten waste plastic using a specific surface area expanding means (hereinafter also referred to as a specific surface area expanding step); The method includes a step of mixing the molten waste plastics with an increased specific surface area with the raw material oil in a dissolving tank equipped with a stirring means (hereinafter also referred to as a first mixing step).

[0065] The manufacturing method of the seventh embodiment includes a step of increasing the specific surface area of ​​the molten waste plastics, which allows the molten waste plastics to be broken down into smaller pieces and fed to the dissolving tank. As a result, a molten waste plastic mixed oil is obtained in which the molten waste plastics are well dissolved in the raw material oil. According to the seventh embodiment, a method for producing a mixed oil of molten waste plastics that can improve the solubility of molten waste plastics in raw oil is realized. The production method of the seventh embodiment can be carried out using, for example, the melting apparatus of any one of the first to fifth embodiments and the waste plastic decomposition apparatus of the sixth embodiment.

[0066] In the manufacturing method of the seventh embodiment, the specific surface area expanding means described in the first to fifth embodiments can be used as the specific surface area expanding means. In the manufacturing method of the seventh embodiment, the stirring means described in the first embodiment can be used as the stirring means.

[0067] The molten waste plastic mixed oil obtained by the manufacturing method of the seventh embodiment is preferably used to manufacture a waste plastic decomposition processing mixture (hereinafter also referred to as a decomposition processing mixture) for decomposing waste plastics in a decomposition processing device, from the viewpoint of making it easier to decompose waste plastics in a decomposition processing device. The mixture for decomposition treatment is produced (prepared) by mixing the melted waste plastic mixed oil with raw material oil.

[0068] [Manufacturing Method Mode 1] An embodiment of a method for producing a molten mixed oil of waste plastics and a mixture for decomposition treatment using the treatment system 100 shown in FIG. 8 will be described. The processing system 100 includes the dissolution apparatus 1 of the first embodiment. Hereinafter, for the sake of convenience, the raw material oil used to produce the molten waste plastic mixed oil may be referred to as the first raw material oil, and the raw material oil used to produce the mixture for cracking treatment may be referred to as the second raw material oil. The ordinal expressions "first" and "second" are used to distinguish between elements and do not imply an order.

[0069] <Overall structure> 8 includes a kneader 20, a dissolving tank 60, a line mixer 30 (an example of a mixing device), a storage tank 40, a residual oil fluid catalytic cracking unit (RFCC unit 50) (an example of a cracking treatment device), a first transport line 10, a molten waste plastic supply line 15X, a mixed oil transport line 15, a first feedstock oil supply line 12, a second feedstock oil supply line 13, a second transport line 14, and a specific surface area expanding means 70. The processing system 100 also includes a waste plastic supply control means 25 and feedstock oil supply control means 121, 131.

[0070] (Kneader 20) The kneader 20 prepares molten waste plastic by melting the waste plastic. Molten waste plastic refers to solid waste plastic that has been melted and turned into a 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.

[0071] 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 sending 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 kneader 20 is not particularly limited, but examples thereof include extruders (such as single-screw extruders and multi-screw extruders), kneaders, and mixers. 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.

[0072] (First Transport Line 10) The first transportation line 10 is connected to the RFCC unit 50 and transports the feedstock oil to the RFCC unit 50 . The first transportation line 10 has, in order from the upstream side, a branch point B1 where it branches into a first feedstock oil supply line 12 and a second feedstock oil supply line 13, and a junction C1 where it joins with the second transportation line . 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.

[0073] (First feed oil supply line 12) The first feedstock supply line 12 branches off from the first transportation line 10 at a branch point B1, and further branches off at a branch point B3 to supply the first feedstock to the dissolution tank 60. A heat exchanger HE for controlling the temperature of the first feedstock oil and a feedstock oil supply control means 121 are provided along the first feedstock oil supply line 12. The feedstock oil supply control means 121 has a regulation valve 122 and a controller 123. The feedstock oil supply control means 121 controls the supply amount of the first feedstock oil by sending a control signal from the controller 123 to the regulation valve 122 and controlling the operation of the regulation valve 122. The controller 123 can be a microcomputer or the like.

[0074] (Second feed oil supply line 13) The second feedstock supply line 13 connects the first transport line 10 and the line mixer 30 and supplies the second feedstock 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 along the second feed oil supply line 13. The feedstock oil supply control means 131 has a control valve 132 and a controller 133. The operation of the feedstock oil supply control means 131 is similar to the operation of the feedstock oil supply control means 121.

[0075] (Molten waste plastic supply line 15X) The molten waste plastic supply line 15X connects the kneader 20 and the dissolution tank 60, and supplies the molten waste plastic from the kneader 20 to the dissolution tank 60. A specific surface area increasing means 70 is arranged on the molten waste plastic supply line 15X.

[0076] (Means for increasing specific surface area) In the case of FIG. 8, the specific surface area enlarging means 70 is a stretched plate as shown in FIG. 2A or a perforated plate as shown in FIG. 2B.

[0077] (dissolving tank 60) The dissolution tank 60 is provided with a rotor as the stirring means 80. The rotor is connected to a motor (not shown). A gear pump 61 is connected to the dissolving tank 60. The pump is not limited to the gear pump 61. The dissolving tank 60 may supply the molten waste plastic mixed oil to the line mixer 30 by its own pressure.

[0078] (Mixed oil transport line 15) The mixed oil transport line 15 connects the dissolving tank 60 and the line mixer 30 , and supplies the molten waste plastic mixed oil produced in the dissolving tank 60 from the dissolving 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.

[0079] (Line Mixer 30) The line mixer 30 includes an agitator blade 90 as an agitating means. The agitator blade 90 is connected to a motor (not shown). 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 also be a continuous mixer.

[0080] (Storage tank 40) The storage tank 40 stores the mixture for decomposition treatment produced in the line mixer 30. A centrifugal pump 41 is connected to the storage tank 40. The pump is not limited to the centrifugal pump 41. The storage tank 40 may supply the mixture for decomposition treatment to the RFCC device 50 by its own pressure. The storage tank 40 may also have a stirring means (for example, a rotor or the like).

[0081] (Second Transport Line 14) In the case of FIG. 8, the second transport line 14 transports the mixture for decomposition treatment produced in the line mixer 30 to the second storage tank 40, and then transports it to the junction C1 with the first transport line 10.

[0082] (RFCC device 50) The RFCC unit 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 feedstock 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).

[0083] When using the treatment system 100 shown in Fig. 8, the mixed oil of molten waste plastics is produced through a specific surface area increasing step and a first mixing step. The mixture for decomposition treatment is further produced through a second mixing step.

[0084] <Specific surface area expansion process> The molten waste plastics discharged from the kneader 20 pass through the specific surface area increasing means 70 arranged in the molten waste plastics supply line 15X, thereby increasing the specific surface area.

[0085] <First mixing process> In the first mixing step, the molten waste plastics with an increased specific surface area are mixed with the first feed oil supplied from the first feed oil supply line 12 in a dissolution tank 60 equipped with a stirring means 80 .

[0086] The first mixing step is preferably carried out at normal pressure under the conditions that the viscosity of the molten waste plastic mixed oil produced satisfies the following formula (Formula 1), the temperature satisfies the following formula (Formula 2), the rotation speed of the rotor satisfies the formula (Formula 3), and the residence time of the molten waste plastic and the raw material oil in the dissolution tank satisfies the following formula (Formula 4). The stirring means 80 provided in the stirring tank 60 is preferably a rotor. Viscosity of melted waste plastic mixed oil ≦5.0×10 6 mPa·s …(Equation 1) 200℃≦Temperature≦250℃…(Number 2) 3 rpm ≦ rotation speed ≦ 1,000 rpm … (Number 3) Residence time ≧ 5 minutes or more ... (Number 4)

[0087] In the above formula (Mathematical Formula 1), the viscosity of the molten waste plastic mixed oil is preferably as low as possible in order to improve the mixability of the molten waste plastic mixed oil with the second feedstock oil in the second mixing step. In the above formula (Mathematical Formula 4), the residence time depends on the size of the dissolution tank 60, but is preferably 30 minutes or less from the viewpoint of suppressing an increase in costs.

[0088] The temperature is the set temperature of the dissolution tank 60. The dissolution tank 60 is preferably equipped with a temperature detection means (such as a thermometer), and the temperature is preferably controlled by a temperature control means (such as a heat exchanger and a heater). The viscosity of the molten waste plastic mixed oil is the melt viscosity (mPa·s) at 200°C. When the viscosity of the molten waste plastic mixed oil satisfies the above formula (Mathematical Formula 1), the transportability of the molten waste plastic mixed oil is improved.

[0089] The viscosity of the molten waste plastic mixed oil was measured using a rheometer (MCR302 (product number) manufactured by Anton Paar) under the following conditions using a cone plate as a measuring jig. <Condition> Cone-plate measuring system: DIN EN (compliant with ISO 3219 and DIN 53019) ·Angular frequency (ω): 0.1rad / sec~100rad / sec ·Measurement temperature: 200℃ Sample weight: 0.1g to 0.3g

[0090] <Second mixing process> In the second mixing step, the melted waste plastic mixed oil produced in the first mixing step and the second feed oil supplied from the second feed oil supply line 13 are mixed in a line mixer 30 equipped with an agitating blade 90. In the second mixing step, a mixture for cracking treatment is produced. The temperature of the second feedstock is preferably in the same range as the temperature of the feedstock in the first transport line 10 .

[0091] The second mixing step is preferably carried out at a temperature (mixing temperature) of 160°C or higher and 260°C or lower, and at a rotation speed of the agitator blade 90 of 10 rpm or higher and 20,000 rpm or lower, and more preferably at a temperature of 170°C or higher and 240°C or lower, and at a rotation speed of the agitator 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 (such as a thermometer), and the mixing temperature is preferably controlled by a temperature control means (such as a heat exchanger and a heater).

[0092] In the case of Figure 8, the mixture for cracking treatment produced in the second mixing step is stored in the second storage tank 40. The mixture for cracking treatment stored in the second storage tank 40 is transported through the second transportation line 14, and at the junction C1, is merged with the feed oil transported through the first transportation line 10 and supplied to the RFCC unit 50.

[0093] [Manufacturing Method Aspect 2] An embodiment of a method for producing a molten mixed oil of waste plastics and a method for producing a mixture for decomposition treatment will be described using a treatment system 100A shown in Fig. 9. The treatment system 100A includes a melting apparatus 1A of the second embodiment.

[0094] <Overall structure> The treatment system 100A shown in Figure 9 differs from the treatment system 100 shown in Figure 8 in that the first raw oil supply line 12X is connected to the molten waste plastic supply line 15X, and that the specific surface area enlarging means 70 is disposed between the confluence C3 and the dissolution tank 60. The other points are the same as those of the treatment system 100. In the following description, configurations that differ from the processing system 100 will be described, and descriptions of similar configurations will be omitted.

[0095] (Means for increasing specific surface area) The specific surface area enlarging means 70 is a stretched plate as shown in Fig. 2A or a perforated plate as shown in Fig. 2B, as in the first embodiment of the production method. Fig. 2A corresponds to a cross-sectional view taken along line II-II in Fig. 9 when the specific surface area enlarging means 70 is a stretched plate. Fig. 2B corresponds to a cross-sectional view taken along line II-II in Fig. 9 when the specific surface area enlarging means 70 is a perforated plate.

[0096] [Manufacturing Method Aspect 3] An embodiment of a method for producing a molten mixed oil of waste plastics and a method for producing a mixture for decomposition treatment will be described using a treatment system 200 shown in Fig. 10. The treatment system 200 includes a melting apparatus 1B of the third embodiment.

[0097] <Overall structure> The treatment system 200 shown in Figure 10 differs from the treatment system 100 shown in Figure 8 in that the molten waste plastic supply line 15X is branched into a plurality of divided supply lines 73, 74, 731, 732 (an example of a specific surface area increasing means), that a supply line 11 is further provided as a first raw oil supply line, that the dissolution tank 60 is provided with a degassing line 44, and that the storage tank 40 is provided with a degassing line 43. The other points are the same as those of the treatment system 100. In the following description, the configurations different from those of the first embodiment of the manufacturing method will be described, and the description of the same configurations will be omitted.

[0098] When the treatment system 200 shown in FIG. 10 is used, the molten mixed oil of waste plastics and the mixture for decomposition treatment are produced through the following steps.

[0099] <Specific surface area expansion process> The molten waste plastics and the first feed oil supplied from the first feed oil supply line 11 are mixed in the kneader 20 to form a mixture (a mixture of molten waste plastics and the first feed oil). After being discharged from the kneader 20, the mixture flows through the molten waste plastic supply line 15X and the plurality of divided supply lines 73, 74, 731, 732, thereby increasing the specific surface area of ​​the molten waste plastics contained in the mixture.

[0100] <First mixing process> The first mixing step produces a molten waste plastic mixed oil by mixing the mixture containing the molten waste plastic with an expanded specific surface area with the first raw oil supplied from the first raw oil supply line 12 in a dissolution tank 60.

[0101] (First degassing process) In the first mixing step, a first degassing step is carried out. In the first degassing step, gases (e.g., water vapor, volatile organic compounds, etc.) generated from the melted waste plastic mixed oil are discharged from the dissolution tank 60 via a degassing line 44 (an example of a degassing means).

[0102] <Second mixing process> The second mixing step is carried out in the same manner as in the second embodiment of the production method.

[0103] (Second gas release process) 10, a second degassing step is carried out after the second mixing step. In the second degassing step, gases (e.g., water vapor, volatile organic compounds, etc.) generated from the decomposition treatment mixture are discharged from the second storage tank 40 via a degassing line 43 (an example of a degassing means).

[0104] [Manufacturing Method Aspect 4] An embodiment of a method for producing a mixed oil of molten waste plastics and a method for producing a mixture for decomposition treatment will be described using the treatment system 300 shown in FIG. The processing system 300 includes a dissolving apparatus 1C according to the fourth embodiment.

[0105] <Overall structure> The treatment system 300 shown in Fig. 11 differs from the treatment system 100 shown in Fig. 8 in that it includes an additional raw material oil supply line 70X, a circulation line 91 through which a portion of the molten waste plastic mixed oil circulates, the circulation line 91 includes a pump 75 (an example of a specific surface area enlarging means), and a molten waste plastic supply line 15Y is connected to the circulation line 91. The other points are the same as those of the treatment system 100. In the following description, the configurations different from those of the first embodiment of the manufacturing method will be described, and the description of the same configurations will be omitted.

[0106] <Additional feedstock supply line 70X> The additional feedstock oil supply line 70X supplies the additional feedstock oil to the outlet side of the kneader 20. The additional feedstock oil may be the same as or different from the first feedstock oil used in the first mixing step and the second feedstock oil used in the second mixing step. 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.

[0107] When the processing system 300 shown in FIG. 11 is used, the molten mixed oil of waste plastics and the mixture for decomposition processing are produced through the following steps.

[0108] <Specific surface area expansion process> The molten waste plastics prepared in the kneader 20 and the additional raw oil supplied from the additional raw oil supply line 70X are discharged from the kneader 20 and then mixed with a portion of the molten waste plastic mixed oil produced in the dissolution tank 60 at the confluence C12 to form a mixture. The mixture (a mixture of molten waste plastics, additional raw oil, and molten waste plastic mixed oil) passes through the pump 75, thereby increasing the specific surface area of ​​the molten waste plastics contained in the mixture.

[0109] <First mixing process> The mixture (a mixture of molten waste plastic, additional raw material oil, and molten waste plastic mixed oil) passes through pump 75, then circulates through circulation line 91, and is supplied to dissolution tank 60 from mixed oil supply port 102. The first mixing step produces molten waste plastic mixed oil by mixing the mixture (a mixture of molten waste plastic, additional raw material oil, and molten waste plastic mixed oil) with the first raw material oil supplied from the first raw material oil supply line 12 in a dissolution tank 60.

[0110] <Second mixing process> The second mixing step is carried out in the same manner as in the first embodiment of the production method.

[0111] The specific surface area increasing step and the first mixing step during operation of the processing system 300 are performed as follows. The molten waste plastic prepared in the kneader 20 and the additional raw material oil supplied from the additional raw material oil supply line 70X are discharged from the kneader 20, then supplied to the junction C12 of the circulation line 91 and passed through the pump 75 (specific surface area expansion process). The first mixing process produces molten waste plastic mixed oil by mixing the mixture (a mixture of molten waste plastic and additional raw oil) circulating through the circulation line 91 and supplied from the mixed oil supply port 102 with the first raw oil supplied from the first raw oil supply line 12 in the dissolution tank 60. A part of the produced mixed oil of melted waste plastics is discharged into the circulation line 91 and mixed with the mixture at the confluence C12.

[0112] [Manufacturing Method Aspect 5] An embodiment of a method for producing a mixed oil of molten waste plastics and a method for producing a mixture for decomposition treatment will be described using the treatment system 400 shown in FIG. The processing system 400 includes a dissolution apparatus 1D according to the fifth embodiment.

[0113] <Overall structure> The treatment system 400 shown in Figure 12 differs from the treatment system 300 shown in Figure 11 in that the circulation line 92 is connected to the first feedstock oil supply line 12. Other points are the same as those of the treatment system 300. In the following description, the configurations different from those of the fourth embodiment of the manufacturing method will be described, and the description of the same configurations will be omitted.

[0114] When the processing system 400 shown in FIG. 12 is used, the molten mixed oil of waste plastics and the mixture for decomposition processing are produced through the following steps.

[0115] <Specific surface area expansion process> The manufacturing method is carried out in the same manner as in the fourth embodiment.

[0116] <First mixing process> The first mixing step is the same as that of manufacturing method embodiment 4, except that the mixture (a mixture of molten waste plastic, additional raw material oil, and molten waste plastic mixed oil) is mixed with the first raw material oil at the confluence C13 and supplied to the dissolution tank 60.

[0117] <Second mixing process> The second mixing step is carried out in the same manner as in the fourth embodiment of the production method.

[0118] The specific surface area increasing step and the first mixing step during operation of the processing system 400 are performed as follows. The specific surface area increasing step is the same as the specific surface area increasing step when the processing system 400 is in operation. The first mixing process is the same as the first mixing process during operation of the treatment system 400, except that the mixture (molten waste plastic and additional raw material oil) is mixed with the first raw material oil at the confluence C13 and supplied to the dissolution tank 60. A part of the produced molten waste plastic mixed oil is discharged to the circulation line 92 and mixed with the above mixture at the confluence point C12.

[0119] The configuration common to the above-described embodiments will be described.

[0120] <Raw oil> The feedstock is not particularly limited, but is preferably one or more feedstocks selected from 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 (500 neutral fraction mineral oil)), heavy gas oil (HGO), desulfurized heavy gas oil (DS-HGO), desulfurized vacuum residual oil (DS-VC), and deasphalted oil (DAO).

[0121] (Characteristics of feedstock oil) The feedstock preferably satisfies the following formulas (4X), (5), (6) and (7). 0.850g / cm 3 ≦Density (15℃)≦1.150g / cm 3 …(Number 4X) 1.400≦Refractive index (70℃)≦1.650 … (Equation 5) 3.0mm 2 / s≦Kinematic viscosity (75℃)≦55.0mm 2 / s…(Number 6) 240g / mol≦molecular weight≦1000g / mol…(Number 7)

[0122] The molecular weight of the feedstock oil can be calculated in accordance with UOP Method 375-07 (Calculation of UOP Characterization Factor and Estimation of Molecular Weight of Pertroleum Oils).

[0123] The feedstock preferably has a hydrogen bonding term (δh) expressed as Hansen solubility parameters of 1.5 or less and a dipole-dipole term (δp) of 4.0 or less. When the hydrogen bonding strength term (δh), expressed as the Hansen solubility parameter, is 1.5 or less, waste plastics are easily dissolved. The smaller the hydrogen bonding strength term (δh), the better. When the dipole-dipole force parameter (δp), which is expressed by the Hansen solubility parameter, is 4.0 or less, waste plastics are easily dissolved. The smaller the dipole-dipole force parameter (δp), the better.

[0124] The Hansen solubility parameter is a solubility parameter introduced by Hildebrand, which is divided into three components: the London dispersion force term (δd), the dipole-dipole force term (δp), and the hydrogen bonding force term (δh), and is expressed in three-dimensional space. The London dispersion force term (δd) represents the effect of London dispersion force, the dipole-dipole force term (δp) represents the effect of dipole-dipole force, and the hydrogen bonding force term (δh) represents the effect of hydrogen bonding 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). In this embodiment, parameter values ​​described in the literature are used.

[0125] The feedstock oils can be used singly or in combination of two or more. When two or more feedstocks are used in combination, the hydrogen bonding term (δh) of the feedstock is the average value of the hydrogen bonding terms (δh) of each feedstock according to the volume ratio. The same applies to the dipole-dipole term (δp) of the feedstock. For example, in the case of a mixed oil obtained by mixing heavy cracked gas oil (HCO) whose hydrogen bonding strength term (δh) is X and cracked residual oil (CLO) whose hydrogen bonding strength term (δh) is Y in a volume ratio of 6:4 (HCO:CLO), the hydrogen bonding strength term (δh) of the mixed oil is calculated as (6X + 4Y) / 10.

[0126] <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 copolymer, polystyrene, polybutene, ethylene oligomer, butene oligomer, styrene oligomer, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, nylon, epoxy resin, and phenolic resin. 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 plastic preferably includes at least one waste plastic derived from a vinyl polymer (e.g., polyethylene, polypropylene, propylene-ethylene copolymer, polystyrene, polybutene, ethylene oligomer, butene oligomer, 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 polystyrene-derived waste plastics and ethylene vinyl acetate-derived waste plastics. Substantially free means that the content of polystyrene-derived waste plastics and ethylene vinyl acetate-derived waste plastics is 10% by mass or less, preferably 5% by mass or less, of the total amount of waste plastics.

[0127] (Melt viscosity of molten waste plastic) 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 …(number 10) The viscosity A is the melt viscosity (mPa·s) of molten waste plastic at 200°C. Melt viscosity (viscosity A) is 1.0 x 10 6If the viscosity is equal to or higher than mPa·s, the waste plastics can be melted without applying an excessive load to the kneader 20, making it easier to control the amount of molten waste plastics. Melt viscosity (viscosity A) is 1.0 x 10 8 If the pressure is less than mPa·s, the waste plastic can be melted by the frictional heat between the molten resins in addition to the load on the kneader 20 to a certain extent. The melt viscosity (viscosity A) of the molten waste plastics can be measured in the same manner as the viscosity of the molten waste plastics mixed oil described above.

[0128] (Density, refractive index, kinematic viscosity, and residual ratio of the filtrate of the decomposition treatment mixture) In the first to fifth aspects of the production method, the mixture for decomposition treatment produced in the second mixing step preferably satisfies the following formulas (1X), (2X), and (3X). 0.850g / cm 3 ≦Density (15℃)≦1.150g / cm 3 …(Number 1X) 1.400≦Refractive index (70℃)≦1.650 …(number 2X) 4.0mm 2 / s≦Kinematic viscosity (200℃)≦20.0mm 2 / s…(number 3X)

[0129] Density (15°C) indicates the density at 15°C. The density (15°C) of the cracking mixture 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." The refractive index (70°C) indicates the refractive index at 70°C. 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). The kinematic viscosity (200°C) indicates the kinematic viscosity at 200°C. The kinematic viscosity (200°C) of the mixture for cracking treatment is a value estimated in accordance with the method for estimating kinematic viscosity at any temperature in JIS K2207, after measuring the kinematic viscosity at 150°C and 180°C in accordance with the high-temperature kinematic viscosity test method for "petroleum asphalt" in JIS K2207 (1996).

[0130] (Remaining filter matter ratio) When the decomposition treatment mixture is passed through a 40 mesh filter, it is preferable that the ratio of the remaining filtered matter to the waste plastics contained in the decomposition treatment mixture (filtered matter / waste plastics contained in the decomposition treatment mixture) is 0.35 or less in mass ratio. The residual ratio of the filtered matter being 0.35 or less in mass ratio means that the molten waste plastics and the raw material oil are mixed in a nearly uniform state in the mixture for decomposition treatment. The filtered material refers to the waste plastics (waste plastics dissolved in raw oil) contained in the decomposition treatment mixture that did not pass through the 40 mesh filter (unit: kg). For example, if 49 kg of raw 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 of mixture for decomposition treatment is passed through a 40 mesh filter, and the amount of material that did not pass through the filter (filtered matter) is 0.35 kg, The residual ratio of the filtrate (filtrate / waste plastic contained in the mixture for decomposition treatment) is calculated to be 0.35 (0.35 / 1.0) in mass ratio.

[0131] [Other aspects] The dissolving apparatus according to the first to fifth embodiments may be provided with two or more types of specific surface area enlarging means. The two or more types of specific surface area enlarging means may be the same or different from each other.

[0132] In the first to fifth aspects of the production method, the melted waste plastic mixed oil may be produced using two or more dissolving tanks 60. The arrangement of the dissolving tanks 60 is not particularly limited. The two or more dissolving tanks 60 may be the same or different from each other. In the first to fifth aspects of the production method, the mixture for decomposition treatment may be produced 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 as or different from each other. In the first to fifth aspects of the production method, the mixture for decomposition treatment produced in the line mixer 30 may be circulated to at least one of the dissolution tank 60 and the line mixer 30 via a circulation line. In the first to fifth embodiments of the production method, additional feedstock oil may be supplied to the line mixer 30 . In the first to fifth aspects of the production method, 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.

[0133] In the first to fifth aspects of the production method, the mixture for decomposition treatment produced in the line mixer 30 may be supplied to the RFCC device without being stored in the second storage tank. In the first to fifth aspects of the production method, the mixture for decomposition treatment produced in the line mixer 30 may be supplied directly to the RFCC device through the second transport line. [Industrial Applicability]

[0134] The melting apparatus of the present invention can produce a mixed oil of melted waste plastics that can increase the utilization efficiency of chemical recycling of waste plastics, and is therefore industrially applicable. [Explanation of symbols]

[0135] DESCRIPTION OF SYMBOLS 1, 1A, 1B, 1C, 1D... Melting device, 10... First transport line, 11, 12, 12X... First raw oil supply line, 13... Second raw oil supply line, 14... Second transport line, 15... Mixed oil transport line, 15X, 15Y... Melted waste plastic supply 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... Degassing line, 50... RFCC device, 60, 60A... Melting tank, 61... Gear pump , 62...Agitating blade, 63...Shaft, 64...Pair of support rods, 65...Dissolving tank main body, 70...Means for increasing specific surface area, 70A, 70B...Main body, 71...Opening, 72...Hole, 73, 74, 731, 732...Split supply line, 70X...Additional raw oil supply line, 75...Pump, 80...Agitating means, 90...Agitating blade, 91, 92...Circulation line, 100, 100A, 200, 300, 400...Treatment system, 102...Mixed oil supply port, 111, 121, 131, 171...Raw oil supply control means, 112, 122, 132, 172...Control valve, 113, 123, 133, 173...Controller, HG...Heat exchanger.

Claims

1. A melting device for dissolving molten waste plastics in raw oil to obtain molten waste plastic mixed oil, a dissolution tank equipped with a stirring means; One or more molten waste plastic supply lines for supplying the molten waste plastic to the dissolution tank; one or more feedstock supply lines for supplying the feedstock to the dissolution tank; a specific surface area expanding means arranged in the molten waste plastic supply line and expanding the specific surface area of ​​the molten waste plastic; The raw oil supply line is connected to at least one of the dissolving tank and the molten waste plastic supply line, The specific surface area increasing means is at least one of a stretching means, a perforated plate, and a divided supply line. Melting equipment.

2. A melting device for dissolving molten waste plastics in raw oil to obtain molten waste plastic mixed oil, a dissolution tank equipped with a stirring means; One or more molten waste plastic supply lines for supplying the molten waste plastic to the dissolution tank; one or more feedstock supply lines for supplying the feedstock to the dissolution tank; A plurality of outlets for discharging the molten waste plastic mixed oil obtained in the dissolving tank from the dissolving tank; A circulation line connected to one of the plurality of discharge ports and circulating a portion of the molten waste plastic mixed oil; A specific surface area expanding means is provided in the circulation line and expands the specific surface area of ​​the molten waste plastic, The raw oil supply line is connected to at least one of the dissolving tank and the molten waste plastic supply line, At least one of the molten waste plastic supply lines is connected to the circulation line. Melting equipment.

3. The melting apparatus according to claim 2, The circulation line is connected to a feed oil supply line. Melting equipment.

4. The melting apparatus according to claim 2, The dissolving tank has a mixed oil supply port through which the molten waste plastic mixed oil circulating through the circulation line is supplied, the circulation line connects the mixed oil supply port and one of the plurality of discharge ports; Melting equipment.

5. The melting apparatus according to any one of claims 2 to 4, The specific surface area increasing means is at least one of a stretching means, a perforated plate, a pump, and a divided supply line. Melting equipment.

6. The melting apparatus according to any one of claims 1 to 5, the stirring means is a stirring blade, The stirring blade is a helical ribbon blade. Melting equipment.

7. The melting apparatus according to claim 6, The blade width w (m) of the impeller is defined as the inner diameter of the dissolution tank D (m) and the impeller diameter of the impeller d ０ When (m), the following formulas (X1) and (X2) are satisfied: Melting equipment. w ≧ 0.10D ... (number X1) d ０ : ≥0.85D … (number x 2)

8. The melting apparatus according to claim 6 or 7, The clearance Dy (m) between the dissolution tank and the stirring blade is expressed by the following equation: D (m) is the inner diameter of the dissolution tank, and d (m) is the stirring blade diameter of the stirring blade. ０ When (m), the following formulas (Y1) and (Y2) are satisfied: Melting equipment. Dy = (D - d ０ ) / 2 … (Equation Y1) Dy≦0.075D ... (number Y2)

9. The melting apparatus according to any one of claims 6 to 8, When the height of the dissolution tank is L (m) and the inner diameter of the dissolution tank is D (m), L / D satisfies the following mathematical formula (number Z): Melting equipment. 0.8≦L / D≦1.6...Formula (number Z)

10. The melting apparatus according to any one of claims 1 to 9, a temperature control means for controlling the temperature of the dissolution tank; Melting equipment.

11. The melting apparatus according to any one of claims 1 to 10, The waste plastic before melting is waste plastic containing at least one of polyethylene-derived waste plastic and polypropylene-derived waste plastic, Melting equipment.

12. The melting device according to any one of claims 1 to 11; A decomposition treatment device that decomposes waste plastics. Waste plastic decomposition equipment.

13. The melting apparatus according to claim 12, The cracking treatment device is a fluid catalytic cracking device. Waste plastic decomposition equipment.

14. A method for producing a molten waste plastic mixed oil by dissolving molten waste plastic in raw oil, In one or more molten waste plastic supply lines for supplying the molten waste plastic, a step of expanding the specific surface area of ​​the molten waste plastic using a specific surface area expanding means; The melted waste plastics having an expanded specific surface area are mixed with the raw material oil in a dissolving tank equipped with a stirring means, The specific surface area increasing means is at least one of a stretching means, a perforated plate, and a divided supply line. A manufacturing method for mixed oil made from melted waste plastics.

15. A method for producing a molten waste plastic mixed oil by dissolving molten waste plastic in raw oil, A step of mixing the molten waste plastic and the raw material oil in a dissolving tank equipped with a stirring means; The melted waste plastic mixed oil obtained in the mixing step is a process of expanding the specific surface area of ​​the melted waste plastic in a circulation line in which a portion of the melted waste plastic mixed oil discharged from the outlet of the dissolution tank circulates, using a specific surface area expanding means; and supplying the molten waste plastic mixed oil containing the molten waste plastic with an expanded specific surface area back to the dissolving tank through a mixed oil supply port provided in the dissolving tank, The circulation line connects the discharge port of the dissolution tank and the mixed oil supply port. A manufacturing method for mixed oil made from melted waste plastics.

16. The method for producing a mixed oil of molten waste plastics according to claim 15, The specific surface area increasing means is at least one of a stretching means, a perforated plate, a pump, and a divided supply line. A manufacturing method for mixed oil made from melted waste plastics.

17. In the method for producing a molten waste plastic mixed oil according to any one of claims 14 to 16, the stirring means is a rotor, The mixing step is carried out at normal pressure, and the viscosity of the molten waste plastic mixed oil produced satisfies the following formula (Formula 1), the temperature satisfies the following formula (Formula 2), the rotation speed of the rotor satisfies the formula (Formula 3), and the molten waste plastic and the raw material oil in the dissolution tank are The residence time is performed under the condition that satisfies the following formula (Formula 4): A manufacturing method for mixed oil made from melted waste plastics. Viscosity of melted waste plastic mixed oil ≦5.0 × 10 ６ mPa·s... (Equation 1) 200℃≦Temperature≦250℃…(Math. 2) 3 rpm≦rotation speed≦1,000 rpm (Equation 3) Residence time ≧ 5 minutes or more ... (Equation 4)

18. In the method for producing a molten waste plastic mixed oil according to any one of claims 14 to 17, The molten waste plastic mixed oil is used to produce a mixture for decomposing waste plastics in a decomposition treatment device. A manufacturing method for mixed oil made from melted waste plastics.

19. In the method for producing a molten waste plastic mixed oil according to claim 18, The cracking treatment device is a fluid catalytic cracking device. A manufacturing method for mixed oil made from melted waste plastics.

20. In the method for producing a molten waste plastic mixed oil according to any one of claims 14 to 19, The waste plastic before melting is waste plastic containing at least one of polyethylene-derived waste plastic and polypropylene-derived waste plastic, A manufacturing method for mixed oil made from melted waste plastics.

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