Waste plastics oil converting device

Abstract

To provide a waste plastic oil converting device that enables highly efficient decomposition of waste plastics under normal pressure.SOLUTION: A waste plastic oil converting device for decomposing waste plastics and generating oil under normal pressure, comprises: a reaction tank into which waste plastics are put; a heating chamber in which the reaction tank is installed inside thereof; a heating device that supplies a heat source to the heating chamber; a steam inlet that introduces steam into the reaction tank; and a discharge section that discharges oil produced by decomposition in the reaction tank. The steam introduced into the reaction tank is heated by the heating device to become superheated steam, which acts as a catalyst for hydrolyzing waste plastics.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an apparatus for producing oil from waste plastics by decomposing waste plastics with high efficiency under normal pressure to produce oil. [Background technology]

[0002] Waste plastics are treated as industrial waste or general waste. Specific examples of waste plastics include polyvinyl chloride, polyethylene, polystyrene, styrofoam, synthetic rubber, synthetic fibers, and waste tires (synthetic rubber-based). These waste plastics are often generated from packaging materials such as waste styrofoam, waste vinyl, synthetic rubber scraps, waste tires (synthetic rubber-based), waste sheets, waste synthetic resin products, waste polyvinyl chloride pipes, waste polyvinyl chloride joints, and the like. If such waste plastics could be converted into oil, it would be an effective technology in terms of resources and the environment.

[0003] Conventionally, various technologies have been proposed for decomposing waste plastics to produce oil. Technologies for producing oil by melting and decomposing waste plastics and technologies for producing oil by using high-temperature steam are known. However, all of these technologies are expensive and have poor oil production efficiency, making them impractical.

[0004] Therefore, a technology has been proposed that can efficiently decompose waste plastics under normal pressure by reacting them with superheated steam, without the need for a catalyst, to produce oil, which can then be safely extracted (see, for example, Patent Document 1).

[0005] Patent Document 1 describes the following: "A plastic oil-making apparatus comprising a reaction vessel for decomposing plastics, a heating chamber in which the reaction vessel is installed, a heating device, and a discharge section for discharging water vapor and decomposed products of plastics from the reaction vessel, the reaction vessel having a water vapor introduction layer covering at least a part of the reaction vessel on the outside of the heating chamber, an introduction section for introducing water vapor into the water vapor introduction layer, and a water vapor ejection nozzle for ejecting water vapor from the water vapor introduction layer into the reaction vessel, the heating device superheats the water vapor introduced into the water vapor introduction layer, and the superheated water vapor is ejected from the water vapor introduction layer through the water vapor ejection nozzle into the reaction vessel, whereby the plastics are decomposed in the water vapor gas phase within the reaction vessel, and the oil produced by the decomposition is discharged to the outside of the reaction vessel via the discharge section together with the water vapor ejected into the reaction vessel via the water vapor ejection nozzle." [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2009-221236 Summary of the Invention [Problem to be solved by the invention]

[0007] According to Patent Document 1, in a reaction tank heated by a heating device, waste plastics react with the superheated steam ejected into the reaction tank, and are efficiently decomposed in the steam gas phase under normal pressure without the need for a catalyst. Also, it is said that the superheated steam reacts efficiently with plastics in the plastic storage section of the reaction tank, and the plastics are efficiently decomposed in the steam gas phase.

[0008] However, although Patent Document 1 describes that superheated steam and plastics react efficiently, it does not disclose any mechanism for why this happens. Furthermore, not only the technology described in Patent Document 1, but also existing technologies have not been used to efficiently and inexpensively process waste plastics.

[0009] An object of the present invention is to provide an apparatus for producing oil from waste plastics, which is capable of decomposing waste plastics with high efficiency under normal pressure. [Means for solving the problem]

[0010] In order to solve the above problems, the waste plastics oil-making apparatus of the present invention is an apparatus for producing oil by decomposing waste plastics under normal pressure, and has a reaction tank into which waste plastics are fed, a heating chamber in which the reaction tank is installed, a heating device that supplies a heat source to the heating chamber, a steam inlet section that introduces steam into the reaction tank, and a discharge section that discharges the oil produced by decomposition in the reaction tank, and the steam introduced into the reaction tank is heated by the heating device to become superheated steam, which acts as a catalyst for hydrolyzing the waste plastics.

[0011] According to this configuration, by heating the steam to produce subcritical steam, i.e., superheated steam, it becomes possible to use the subcritical water as a catalyst, which promotes hydrolysis of the waste plastic P and separates and generates the oil contained in the waste plastic P.

[0012] In the waste plastics oil production apparatus according to the present invention, the heating device may be configured to heat the steam introduced from the steam inlet until it becomes superheated steam in a subcritical state of 250 to 300°C.

[0013] According to such a configuration, the superheated steam in a subcritical state of 250 to 300° C. effectively acts as a catalyst, and the oil contained in the waste plastic P can be separated and generated without using a separate catalyst.

[0014] In the waste plastics oil production apparatus according to the present invention, the waste plastics are at least one of polyvinyl chloride, polyethylene, polystyrene, polyacrylamide, polystyrene foam, synthetic rubber, synthetic fiber, and waste tires.

[0015] According to this configuration, it becomes possible to convert various types of waste plastics into oil, and to generate renewable energy with high efficiency. Effect of the Invention

[0016] According to the present invention, by heating water vapor to produce subcritical water vapor, i.e., superheated steam, it becomes possible to use the subcritical water as a catalyst, which promotes the hydrolysis of waste plastics and separates and generates the oil contained in the waste plastics. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic diagram showing an example of the overall external configuration of an apparatus for converting waste plastics into oil according to an embodiment of the present invention. [Diagram 2] 1 is a graph showing the temperature dependence of ionic product, which is one of the physical properties that greatly affects the properties of water. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing an example of the overall external configuration of an apparatus for producing oil from waste plastics (hereinafter referred to as oil production apparatus 100) according to an embodiment of the present invention. Note that FIG. 1 shows a perspective view of the internal configuration of the apparatus 100. The overall configuration and operation of the apparatus 100 will be described with reference to FIG. 1. The apparatus 100 makes it possible to decompose waste plastics with high efficiency under normal pressure.

[0019] <Configuration of Oil-producing Apparatus 100> Specific examples of waste plastics that can be treated by the oil-producing apparatus 100 include polyvinyl chloride, polyethylene, polystyrene, polyacrylamide, polystyrene foam, synthetic rubber, synthetic fiber, waste tires (synthetic rubber-based), etc. In the following description, waste plastics may be referred to as "waste plastics." The oil-producing apparatus 100 may simultaneously treat one type of waste plastic or multiple types of waste plastics.

[0020] The oilification apparatus 100 has a reaction tank 10 into which waste plastic is introduced, and a heating chamber 20 that covers the sides and bottom of the reaction tank 10. The reaction tank 10 is configured to have a bottomed hollow shape for decomposing the introduced waste plastic. For example, the reaction tank 10 may be configured to have a rectangular parallelepiped or cylindrical shape. The heating chamber 20 is configured to be large enough to accommodate the reaction tank 10 therein, and heats the reaction tank 10 from outside. The outer wall of the heating chamber 20 is covered with a heat insulating section 21.

[0021] The upper part of the reaction vessel 10 penetrates the upper surface of the heating chamber 20 and opens so as to be exposed to the outside of the heating chamber 20. This upper opening 13 functions as an inlet for the waste plastic P. A lid 11 is provided on the upper opening 13 so as to be able to open and close. The reaction vessel 10 is arranged so that its side and bottom surfaces are located inside the heating chamber 20. The heating chamber 20 may be arranged so that the outer periphery of the bottom surface of the reaction vessel 10 contacts the inner periphery of the bottom surface of the heating chamber 20, but feet (feet 12 shown in FIG. 1) may be provided on the outer periphery of the bottom surface of the reaction vessel 10, and the reaction vessel 10 may be supported via the feet 12.

[0022] In addition, the reaction tank 10 has a steam inlet 15 formed on the side wall and bottom surface. The steam inlet 15 is connected to a steam inlet pipe 31 on the upper surface of the reaction tank 10. The steam inlet pipe 31 is connected to a steam supply unit 200 provided outside the oilification apparatus 100, and the steam supplied from the steam supply unit 200 is guided to the steam inlet 15. The steam supply unit 200 can be composed of, for example, a boiler. The hollow part of the reaction tank 10 functions as the waste plastic storage unit 10A. In addition, an exhaust pipe 32 is connected to the upper part of the reaction tank 10 for discharging steam and decomposition products of waste plastic (liquid phase, solid phase, gas phase, or a mixture thereof).

[0023] The tip of the steam introduction section 15 is formed so as to open into the waste plastic storage section 10A. This opening section is referred to as the injection nozzle section 15A. A plurality of injection nozzle sections 15A are provided, so that steam can be evenly injected into the waste plastic storage section 10A. The opening diameter of the injection nozzle sections 15A is not particularly limited. The number of injection nozzle sections 15A is also not particularly limited. The other end of the steam introduction section 15 is connected to a steam introduction pipe 31. The decomposition process of waste plastic in the oilification apparatus 100 can be performed in batches, continuously, or intermittently.

[0024] A heating device 35 such as a burner is provided in a portion of the lower side wall of the heating chamber 20. The heating device 35 supplies a heat source to the inside of the heating chamber 20. Therefore, the heating device 35 further heats the steam introduced into the steam inlet 15. The heating device 35 also indirectly heats the reaction tank 10. The temperature of the superheated steam sprayed into the reaction tank 10 may be determined taking into consideration the type and weight of the waste plastic to be decomposed and the quality of the generated oil. The temperature of the superheated steam may be measured, for example, by a temperature sensor provided in the reaction tank 10. The number of heating devices 35 is not limited.

[0025] <Function of the oil producing device 100> First, waste plastic P to be decomposed is put into the reaction tank 10. Steam is introduced from the steam supply unit 200 to the steam inlet unit 15. Meanwhile, the heating device 35 is driven to heat the steam introduced into the steam inlet unit 15 in the heating chamber 20. At the same time, the reaction tank 10 is heated. In this way, the steam is superheated. The superheated steam is ejected from the reaction tank 10. In the reaction tank 10, the decomposition reaction of the waste plastic P proceeds due to the catalytic action of the superheated steam.

[0026] Oil is generated by the decomposition of the waste plastic P. The generated oil is led to the discharge section (discharge pipe 32) by the steam that is sprayed into the reaction tank 10, either suspended in the steam or in another state. The oil led to the discharge pipe 32 is discharged to the outside of the reaction tank 10. It is advisable to provide a suction fan or the like in the discharge pipe 32, and discharge the oil by its operation.

[0027] <Mechanism of catalytic action of superheated steam> It is known that when the temperature range of water is expanded to subcritical water above 100°C, properties completely different from those in the temperature range around room temperature emerge. Subcritical water is characterized by its high ionic product. Figure 2 shows a graph of the temperature dependence of the ionic product, which is one of the physical properties that greatly affects the properties of water. The ionic product is the ratio of the hydrogen ions H + and hydroxide ion OH - The ionic product is 10 in water at room temperature and pressure. -14 (mol / kg) 2 However, in subcritical water at 250-300℃ and 1.6MPa, the -11 (mol / kg) 2 It will be about 1000 times larger.

[0028] At this time, hydrogen ions H + and hydroxide ion OH -Since the ionic product of water at room temperature is about 30 times that of water at room temperature, the water itself, that is, the subcritical water, acts as an acid or alkali catalyst, promoting hydrolysis reactions. In other words, at high temperatures, water becomes subcritical water, self-dissociates, and acts as an acid or alkali catalyst, promoting hydrolysis. As a result of the above, subcritical water at high temperatures has properties between water at room temperature and organic solvents, and the strength of the effects of both properties in subcritical water can be controlled by changing the temperature and pressure.

[0029] Hydrolysis is a reaction in which water reacts with a reactant to produce a decomposition product. At this time, the water molecule (H2O) is split into H (proton component) and OH (hydroxide component) on the product and is absorbed. When compound AB has polarity, A is positive and B is negative, when AB reacts with water, A bonds with OH and B bonds with H. This is the general reaction format.

[0030] Therefore, according to the oil-producing apparatus 100, by heating steam to produce subcritical steam, i.e., superheated steam, it becomes possible to use subcritical water as a catalyst, which promotes hydrolysis of the waste plastic P and separates and generates oil contained in the waste plastic P. Furthermore, according to the oil-producing apparatus 100, it is possible to decompose the waste plastic P with high efficiency under normal pressure, which makes it highly safe. Moreover, according to the oil-producing apparatus 100, since the properties of superheated steam are utilized, no other catalyst is required.

[0031] Although the embodiment of the present invention has been described above, this embodiment is presented as an example and is not intended to limit the scope of the invention. These novel embodiments described above can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims. [Explanation of symbols]

[0032] 10 reaction vessels, 10A Waste plastic storage section, 11 Lid, 12 feet, 13 Top opening; 15 Steam inlet, 15A Injection nozzle part, 20 heating chamber, 21 Insulation section, 31 Steam inlet pipe, 32 discharge pipe, 35 heating equipment; 100 Waste plastics oil production equipment, 200 Steam supply section.

Claims

1. A waste plastics oil production apparatus that decomposes waste plastics under normal pressure to produce oil, A reaction tank into which waste plastics are introduced; a heating chamber in which the reaction vessel is disposed; A heating device that supplies a heat source to the heating chamber; A steam inlet for introducing steam into the reaction vessel; A discharge section for discharging oil generated by decomposition in the reaction tank, The steam introduced into the reaction vessel is The waste plastics are heated by the heating device to become superheated steam, which acts as a catalyst for hydrolysis of the waste plastics. Equipment for turning waste plastics into oil.

2. The heating device includes: The steam introduced from the steam inlet is heated until it becomes superheated steam in a subcritical state of 250 to 300 ° C. The apparatus for producing oil from waste plastics according to claim 1.

3. The waste plastics are At least one of polyvinyl chloride, polyethylene, polystyrene, polyacrylamide, polystyrene foam, synthetic rubber, synthetic fiber, and waste tires; 3. The apparatus for producing oil from waste plastics according to claim 1 or 2.

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