Method for improving the combustion properties of oils containing a lot of aromatic components, and method for producing fuel for internal combustion engines

Abstract

A new method is provided for using flame-retardant oils, such as waste tire oil, that contain a large amount of flame-retardant aromatic components as an internal combustion engine fuel. The present invention provides a method for producing fuel for internal combustion engines, comprising a mixing step of mixing a flame-retardant oil containing a large amount of flame-retardant aromatic components with a blending oil selected from the group consisting of vegetable oil, diesel, and kerosene, A method for producing an internal combustion engine fuel, comprising: a radical generating treatment step of generating hydroperoxy radicals in the blending oil.

Description

[Technical field]

[0001] The present invention relates to a method for improving the combustibility of oils containing a large amount of flame-retardant aromatic components, such as recycled waste tire oil obtained by recycling waste tires (hereinafter also referred to as "flame-retardant oils"), and also to a method for producing internal combustion engine fuel using said method. [Background technology]

[0002] Technologies related to recycling waste tires have been attracting attention from the perspective of effective resource utilization. The high-temperature gas generated during the pyrolysis of waste tires can be cooled and condensed to obtain liquid oil as waste tire oil. The obtained waste tire oil contains a large amount of flame-retardant aromatic components (e.g., about 76%, see Table 2 in the examples) and has poor combustion characteristics, so it cannot be used as is as fuel for internal combustion engines such as diesel. When using it as fuel for internal combustion engines, it is necessary to mix it with an oil with good combustion characteristics that contains a large amount of unsaturated fatty acids and / or short-chain alkanes (hereinafter referred to as "blending oil" in this specification) to reduce the ratio of flame-retardant aromatic components in the fuel.

[0003] On the other hand, in order to effectively utilize waste tire oil, for example, Patent Document 1 discloses a method for pyrolysis of waste tires that can control the flash point of the waste tire oil. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4644172 Summary of the Invention [Problem to be solved by the invention]

[0005] Although Patent Document 1 describes that the flash point of the waste tire oil is controlled, the resulting waste tire oil still contains a large amount of flame-retardant aromatic components, and when used as an internal combustion engine fuel, it is necessary to mix a large amount of blending oil. Moreover, blending oil with good combustion properties is expensive, which is an issue for using the waste tire oil as an internal combustion engine fuel. The present invention is intended to solve these problems and provides a new method for using flame-retardant oils containing a large amount of flame-retardant aromatic components, such as waste tire oil, as an internal combustion engine fuel. [Means for solving the problem]

[0006] The present inventors have conducted research to solve the above problems and have found that by subjecting blending oil to radical generation treatment, the combustion characteristics of flame-retardant oils are significantly improved even when the blending ratio of the blending oil is low. The present inventors believe that this is because the radical generation treatment of blending oil generates hydroperoxy radicals, which facilitate low-temperature oxidation reactions, thereby improving the combustion characteristics.

[0007] That is, the present invention provides a method for producing fuel for an internal combustion engine, comprising a mixing step of mixing a flame-retardant oil containing a large amount of flame-retardant aromatic components with a blending oil selected from the group consisting of vegetable oil, diesel, and kerosene, and a radical generating treatment step of generating hydroperoxy radicals in the blending oil.

[0008] In the present invention, in the mixing step, the blending oil is preferably contained in an amount of 25% by volume or less, more preferably 20% by volume or less, based on the total amount of the blending oil. It is more preferable that the content is 10% by volume or less, and particularly preferable that the content is 10% by volume or less. It is also preferable that the content is 1% by volume or more, preferably 3% by volume or more, and more preferably 5% by volume or more. In addition, a radical generating treatment step may be performed on the blending oil before the mixing step, and a radical generating treatment step may be performed on the mixed oil after the mixing step.

[0009] The radical generating treatment step is preferably a step of treating the blending oil by one or more methods selected from the group consisting of mixing treatment with ozone and / or hydrogen peroxide, magnetic field treatment, electrolysis treatment, heat treatment, ultraviolet light treatment, and catalytic treatment.

[0010] Another aspect of the present invention is a method for improving the combustibility of a flame-retardant oil containing 40 volume % or more of a flame-retardant aromatic component, comprising: The method includes a step of mixing the blending oil that has been subjected to radical generating treatment with the flame-retardant oil, wherein the blending oil is mixed in an amount of 1 to 25% by volume with respect to the total amount.

[0011] Another aspect of the present invention is a method for improving the combustibility of a flame-retardant oil containing 40 volume % or more of a flame-retardant aromatic component, comprising: The method includes a step of mixing a blending oil with the oil, and a step of subjecting the mixed mixture to radical treatment, in which the blending oil is mixed in an amount of 1 to 25% by volume based on the total amount. Effect of the Invention

[0012] The present invention provides a new method for using a flame-retardant oil containing a large amount of flame-retardant aromatic components, such as waste tire oil, as an internal combustion engine fuel. Specifically, by subjecting the blending oil to radical generation treatment, the combustion characteristics of the flame-retardant oil are improved even if the blending ratio of the blending oil is low, and the flame-retardant oil can be used as an internal combustion engine fuel compatible with conventional internal combustion engines. [Brief description of the drawings]

[0013] [Figure 1] 1 is a diagram showing an overview of an apparatus used in a method for producing fuel for internal combustion engines. [Diagram 2] FIG. 1 is a diagram showing the results of a fuel oil ignition fuel ability test apparatus (FCA). [Diagram 3] FIG. 1 is a diagram showing the results of a fuel oil ignition fuel ability test apparatus (FCA). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The present invention will be described in more detail below, but the scope of the invention is not limited to the specific embodiments.

[0015] One embodiment of the present invention is a method for producing fuel for internal combustion engines, which includes a mixing step of mixing a flame-retardant oil containing a large amount of flame-retardant aromatic components with a blending oil selected from the group consisting of vegetable oil, light oil, and kerosene, and a radical generation treatment step of generating hydroperoxy radicals in the blending oil.

[0016] <Mixing process> The mixing step is a step of mixing the flame-retardant oil and the blending oil. Flame-retardant oil contains a large amount of flame-retardant aromatic components, and is typically waste tire oil. Flame-retardant oil contains a large amount of flame-retardant aromatic components, so it is difficult to use it as an internal combustion engine fuel by itself. The content of flame-retardant aromatic components in flame-retardant oil may usually be 40% by volume or more, 50% by volume or more, 60% by volume or more, or 70% by volume or more. The content of flame-retardant aromatic components in flame-retardant oil is usually 100% by volume or less, and may be 90% by volume or less.

[0017] The blending oil is selected from the group consisting of vegetable oil, light oil and kerosene. Examples of vegetable oil include, but are not limited to, palm oil, soybean oil, rapeseed oil, sunflower oil, palm kernel oil, cottonseed oil, peanut oil, olive oil, coconut oil, corn oil, pongamia oil, etc. From the viewpoint of facilitating low-temperature oxidation reactions, it is preferable that the blending oil contains a large amount of unsaturated fatty acids and / or short-chain alkanes.

[0018] In the mixing step, the blending oil is preferably contained in an amount of 25% by volume or less, more preferably 20% by volume or less, even more preferably 15% by volume or less, and particularly preferably 10% by volume or less, based on the total amount of the blending oil and the flame-retardant oil. Also, the blending oil is preferably contained in an amount of 1% by volume or more, more preferably 3% by volume or more, and even more preferably 5% by volume or more.

[0019] <Radical treatment process> The radical treatment step is a step of generating hydroperoxy radicals in the blending oil. By subjecting the blending oil to radical generation treatment, hydroperoxy radicals are generated, which makes it easier for low-temperature oxidation reactions to occur.

[0020] The radical treatment is not particularly limited as long as it can generate hydroperoxy radicals in the blending oil, but is preferably selected from mixing treatment with ozone and / or hydrogen peroxide, magnetic field treatment, electrolysis treatment, heat treatment, ultraviolet treatment, and catalytic treatment. Only one of these methods may be used, or two or more may be used in combination. For example, when light oil is used as the blending oil, hydroperoxy radicals can be generated by performing heat treatment at a temperature below the flash point temperature after ozone treatment. In the case of vegetable oil containing a large amount of unsaturated fatty acids, hydroperoxy radicals can be generated by heat treatment alone. In addition, ultraviolet treatment and catalytic treatment can be appropriately combined.

[0021] The amount of ozone and hydrogen peroxide to be mixed in the mixing treatment with ozone and / or hydrogen peroxide is not particularly limited, but since it is difficult to dissolve them in the recycled oil, it is necessary to dissolve them using a stirrer such as a mixer. The magnetic field treatment involves applying a magnetic field using a magnetic field generator or a strong magnet to cause an oxidation-reduction reaction, thereby generating hydroperoxy radicals. In the electrolysis, a voltage or potential is applied in a conventional manner to cause an oxidation-reduction reaction, thereby generating hydroperoxy radicals. The heat treatment may be performed at a temperature equal to or lower than the flash point of the blending oil. The heating time is appropriately set depending on the type of blending oil used. The ultraviolet treatment can be carried out by irradiating the blending oil with ultraviolet light using an existing ultraviolet irradiation device. The irradiation time can be appropriately set depending on the type of blending oil used. The catalytic treatment can use existing catalysts used to promote reactions, such as copper, iron, manganese, chromium, nickel, cobalt, etc.

[0022] In the radical generating step, the peroxide value (POV) of the blending oil after the radical treatment is preferably 10 or more, more preferably 12 or more, and is preferably 18 or less, more preferably 15 or less.

[0023] Before the mixing step, the blending oil may be subjected to a radical generating treatment step in advance, and after the mixing step, the mixed oil may be subjected to a radical generating treatment step.

[0024] FIG. 1 shows an overview of an apparatus used in the method for producing fuel for internal combustion engines according to this embodiment. The waste tire oil tank 9 stores the waste tire oil as a fire-retardant oil. Blending oil tank 1A stores vegetable oil, and blending oil tank 1B stores diesel as blending oil. There may be only one blending oil tank, but in the case of only one, the blending oil is subjected to radical treatment and then mixed with the waste tire oil in a batch system, so from the viewpoint of the production efficiency of the internal combustion engine fuel, it is preferable to have two or more blending oil tanks. When there are two or more blending oil tanks, the types of blending oil in the tanks may be the same or different.

[0025] The blending oil tank 1A is equipped with a heater 2A, which can heat the stored vegetable oil. The vegetable oil is heated by appropriately setting the heating temperature and heating time depending on the type of vegetable oil, while oxygen is supplied by the air compressor 3 and mixed, and stirred by the stirrer 5A, to subject the vegetable oil to radical generation treatment, generating hydroperoxy radicals. At that time, the POV of the vegetable oil is adjusted to about 10 to 18, preferably about 12 to 15.

[0026] The blending oil tank 1A may be provided with an ultraviolet ray generator (not shown) for performing radical generation treatment on the top or side of the tank, and an oxidation catalyst (not shown) such as copper, iron, manganese, chromium, nickel, cobalt, etc. may be placed inside the tank. When the oxidation catalyst is placed at a predetermined location, it is preferable to control the temperature so that the blending oil convects inside the tank.

[0027] The blending oil tank 1B is provided with a heater 2B, which can heat the stored diesel fuel. At this time, since the flash point of diesel fuel is about 50°C, care must be taken not to raise the temperature of the diesel fuel too much by heating. While heating, ozone is supplied from the ozone generator 4 and mixed, and the mixture is stirred with the stirrer 5B, whereby the diesel fuel is subjected to radical generation treatment and hydroperoxy radicals are generated. At this time, the POV of the diesel fuel is adjusted to about 10 to 18, preferably about 12 to 15.

[0028] The blending oil tank 1B may be provided with an ultraviolet ray generator (not shown) for performing radical generation treatment on the top or side of the tank, and an oxidation catalyst (not shown) such as copper, iron, manganese, chromium, nickel, cobalt, etc. may be placed inside the tank. When the oxidation catalyst is placed at a predetermined location, it is preferable to control the temperature so that the blending oil convects inside the tank.

[0029] The blending oil that has been subjected to the radical generating treatment is mixed with the waste tire oil in the waste tire oil tank 9. The amount of the blending oil in this case is preferably 1 to 25% by volume or less of the amount of the waste tire oil, and particularly preferably 5 to 10% by volume. The mixed blending oil and waste tire oil are stirred by a stirrer 5C and fed to an internal combustion engine such as a diesel engine.

[0030] The blending oil and the waste tire oil may be mixed by batch processing, but by providing flow meters (not shown) on the lines from the blending oil tank and the waste tire oil tank and adjusting the flow rates of each, it is possible to produce internal combustion engine fuel in a continuous manner. EXAMPLES

[0031] The present embodiment will be described in more detail below with reference to examples, but the scope of the present invention is not limited to these examples.

[0032] <Confirmation of heat generation due to low-temperature oxidation reaction> Waste tire oil 1 was prepared, containing the following components (units: %) as shown in Table 1. Next, commercially available diesel fuel was mixed into waste tire oil 1 at 5% of the total amount, and mixed oil 1 was prepared by magnetic field treatment (POV of mixed oil after magnetic field treatment = 12). The components of mixed oil 1 are shown in Table 1.

[0033] [Table 1]

[0034] The combustion characteristics of the mixed oil 1 and the waste tire oil 1 shown in Table 1 were confirmed using a fuel oil ignition and fuel property test device (FCA). The results are shown in Figure 2. From Figure 2, it was confirmed that mixed oil 1 generated heat due to low-temperature oxidation reactions, as shown by the dotted line. In addition, when the maximum low-temperature heat release rate (maximum ROHR) was measured, it was 0.31 for waste tire oil 1, while it was 0.59 for mixed oil 1. In addition, when the cumulative heat release rate was measured, it was 4.90 for waste tire oil 1, while it was 6.99 for mixed oil 1. From the above, it can be seen that the combustibility of mixed oil 1 was improved, promoting main combustion.

[0035] <Confirmation of the effect of radical generation treatment> Waste tire oil 2 shown in Table 2 was prepared. Next, mixed oil 2 was prepared by mixing pongamia oil (acid value: 13.8 mg KOH / g, fatty acid composition (unit: %) shown in Table 3) with waste tire oil 2 so that the total volume was 50%, mixed oil 3 was prepared by mixing waste tire oil 2 with pongamia oil so that the total volume was 25%, and mixed oil 4 was prepared by mixing waste tire oil 2 with pongamia oil so that the total volume was 10%. Note that no radical generation treatment was performed.

[0036] [Table 2]

[0037] [Table 3]

[0038] The combustion characteristics of the mixed oils 2 to 4 were confirmed using a fuel oil ignition and fuel composition tester (FCA). The results are shown in Figure 3. As shown in Figure 3, mixed oil 2, which was mixed with 50 volume% of the total pongamia oil, and mixed oil 3, which was mixed with 25 volume% of the total pongamia oil, had good combustion characteristics because they contained a large amount of blending oil. On the other hand, mixed oil 4, which was mixed with 10 volume% of the total pongamia oil, had a low-temperature maximum heat release rate (maximum ROHR) of 0.31 and a cumulative heat release rate of 4.92, and the combustion characteristics were at the same level as waste tire oil 1.

[0039] In other words, if the blending oil is not subjected to radical generation treatment, the blending oil content must be increased in order to improve the combustion characteristics of the mixed oil, and when the blending oil content is around 10%, the combustion characteristics are not improved compared to waste tire oil. On the other hand, even if the blending oil content is about 5%, as in the case of mixed oil 1, it can be seen that the combustion characteristics are improved by subjecting the blending oil to radical generation treatment through low-temperature oxidation reactions. [Industrial Applicability]

[0040] The present invention can provide new uses for recycled oil extracted from waste tires. In other words, it can promote the reuse of waste tires, which are a social problem as industrial waste. Furthermore, it can improve the combustion characteristics of flame-retardant oil. In other words, it opens up new uses for flame-retardant oil, which was difficult to use in conventional internal combustion engines. The present invention greatly contributes to reducing the environmental load and is an invention that will contribute greatly to the SDGs. [Explanation of symbols]

[0041] 1A Blending Oil Tank (Vegetable Oil) 1B Blending oil tank (light oil) 2A, 2B heater 3. Air Compressor 4. Ozone Generator 5A, 5B, 5C Stirrer 6 Flow control valve with switching valve 7 Flow Control Valve 8. Three-way valve 9. Waste tire oil tank

Claims

1. A method for producing fuel for an internal combustion engine, comprising: a mixing step of mixing a flame-retardant oil containing a large amount of a flame-retardant aromatic component with a blending oil made of a vegetable oil, A method for producing an internal combustion engine fuel, comprising: a radical generating treatment step of generating hydroperoxy radicals in the blending oil.

2. The method for producing fuel for internal combustion engines according to claim 1 , wherein in the mixing step, the blending oil is contained in an amount of 25% by volume or less based on the total amount of the fuel.

3. The method according to claim 1 or 2, further comprising the step of subjecting the blending oil to a radical generating treatment step prior to the mixing step.

4. The method according to claim 1 or 2, wherein the radical generating treatment step is carried out after the mixing step.

5. 3. The manufacturing method according to claim 1 or 2, wherein the radical generating treatment step comprises treating the blending oil with one or more methods selected from the group consisting of mixing treatment with ozone and / or hydrogen peroxide, magnetic field treatment, electrolysis treatment, heat treatment, ultraviolet light treatment, and catalytic treatment.

6. A method for improving the combustibility of a flame-retardant oil containing 40% by volume or more of a flame-retardant aromatic component, comprising: and mixing the flame-retardant oil with a blending oil made of vegetable oil that has been subjected to a radical-generating treatment, wherein the blending oil is mixed in an amount of 1 to 25% by volume with respect to the total amount of the flame-retardant oil.

7. A method for improving the combustibility of a flame-retardant oil containing 40% by volume or more of a flame-retardant aromatic component, comprising: A step of mixing the blending oil made of vegetable oil with the flame retardant oil, and The method includes a step of subjecting the product to radical treatment, wherein the blending oil is mixed in an amount of 1 to 25% by volume based on the total amount.

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