JP2008266487A - Blended fuel for diesel engine and pour point depressing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide, regarding a blended fuel between a biodiesel and gas oil, a fuel for diesel engines excellent in low-temperature fluidity irrespective of the fatty acid composition of a fat/oil raw material used for the manufacture of the biodiesel. <P>SOLUTION: A modifier prepared by ozonizing a vegetable oil is incorporated in an amount of 0.03-2.0 wt.% in a blended fuel at least containing a biodiesel and gas oil. This can give the blended fuel for diesel engines excellent in low-temperature fluidity. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a mixed fuel for a diesel engine and a method for lowering the pour point thereof. More specifically, the present invention relates to a mixed fuel containing biodiesel and light oil and a method for lowering the pour point thereof.

In recent years, biodiesel can be used as a diesel engine fuel that can reduce carbon dioxide (CO ₂ ) emissions from the viewpoint of preventing air pollution and suppressing global warming, and generates less harmful substances in exhaust gases such as sulfur oxides (SOx). Is attracting attention. Biodiesel is manufactured by using animal and vegetable oils, waste edible oils, and the like as fat and oil raw materials, and methylating the fat and oil raw materials.

Since biodiesel is a fuel derived from animal and vegetable fats and oils, CO ₂ emitted by its use is not counted due to the concept of carbon neutral, and CO ₂ emission can be suppressed. Moreover, animal and vegetable oils and fats raw materials because they do not contain little sulfur, biodiesel produced from oil feed can be kept low SO _x generation. For this reason, biodiesel is promising as an environmentally friendly fuel.

  Rapeseed oil, sunflower oil, etc. are mentioned as what is suitable in the fats and oils used for manufacture of biodiesel. Rapeseed oil or sunflower oil-derived biodiesel is a good raw material for fats and oils because it has relatively good low-temperature fluidity among biodiesel and exhibits a remarkable effect of adding a low-temperature fluidity improver.

  However, there is a problem that the cost is high for mass production of rapeseed oil, sunflower oil and the like for industrial use. In addition, the demand for vegetable oil is increasing with the increase in biodiesel production, and the demand for rapeseed oil and sunflower oil in Europe and the like is increasing year by year. Therefore, it is becoming difficult to meet the demand for biodiesel only with rapeseed oil and sunflower oil.

  From the above circumstances, it is necessary to produce biodiesel from other than rapeseed oil and sunflower oil. In addition to rapeseed oil and sunflower oil, promising raw oils and fats include palm oil and soybean oil, which are produced in large quantities around the world, and jetropha oil that cannot be used as edible oil. According to the announcement by the US Department of Agriculture (USDA) in fiscal 2006, palm oil has the highest production volume by oil type, followed by soybean oil, rapeseed oil, sunflower oil, and the like. Thus, palm oil, soybean oil, and the like are expected to be used as biodiesel fat materials. Non-Patent Documents 1 to 3 describe the current status of biodiesel in countries around the world.

  However, biodiesel has a problem that its pour point is considerably higher than that of commercial light oil. In order to solve this problem, methods for improving the low temperature fluidity of biodiesel include methods such as dewaxing, addition of a low temperature fluidity improver, and mixing with light oil. For example, a low-temperature fluidity improver using a hydroxyl group-containing polyalkyl acrylate copolymer or the like is disclosed (see Patent Document 1). In this regard, the applicant has invented a low-temperature fluidity improver obtained by subjecting vegetable oil to ozone treatment, and has clarified that there is a certain reforming effect (see Patent Document 2).

Special table 2001-524578 PCT International Publication WO2005 / 033252 pamphlet. Matsumura Masatoshi, “Biodiesel Frontline”, Industrial Research Committee, October 31, 2006, p134-137, p192-199. http://www.meti.go.jp/report/downloadfiles/g30625d50j.pdf. Werner Koerbritz “New Trends in Developing Biodiesel World-wide”, ASIA BIO-FUELS “Evaluating & Exploiting the Commercial Uses of Ethanol, Fuel Alcohol & Biodiesel” (2002).

  However, methods for improving the low temperature fluidity of biodiesel, particularly biodiesel rich in saturated fatty acids, have the following problems to be solved.

  The method by dewaxing is troublesome because cooling and crystal removal must be repeated many times, and biodiesel rich in saturated fatty acids is problematic in that the yield is poor.

  The low temperature fluidity improver for biodiesel is effective to some extent for biodiesel containing a lot of unsaturated fatty acids such as rapeseed oil, but it is effective for biodiesel containing a lot of saturated fatty acids such as palm oil and soybean oil. There is a problem that is low.

  The low temperature fluidity of biodiesel is affected by the fatty acid composition of the oil and fat raw material. For example, rapeseed oil and sunflower oil are fats and oils rich in unsaturated fatty acids, and biodiesel produced therefrom can have a remarkable pour point depressing effect by the ozone treatment modifier. However, biodiesel produced from oil and fat raw materials with a high saturated fatty acid such as soybean oil and palm oil tends to have poorer low-temperature fluidity than biodiesel derived from rapeseed oil or sunflower oil. In addition, addition effects such as a pour point depressing action by the modifier are also low. Therefore, at present, it is necessary to use it as a mixed fuel mixed with light oil.

  Thus, the mixed fuel with light oil is one of the methods for improving the low temperature fluidity. Gas oil, which is a fossil fuel, also has a problem that its fluidity deteriorates at low temperatures. Conventionally, chemically synthesized low-temperature fluidity improvers have been used. By mixing biodiesel with light oil containing such an improving agent, fluidity at low temperatures can be ensured. However, since the low temperature fluidity improver for light oil is not effective for biodiesel, particularly biodiesel containing a large amount of saturated fatty acids, the amount of biodiesel in light oil increases and the low temperature fluidity deteriorates. Therefore, low temperature fluidity cannot be improved completely by simply using a mixed fuel mixed with light oil.

  Therefore, the main object of the present invention is to provide a mixed fuel for diesel engines excellent in low-temperature fluidity, regardless of the fatty acid composition of the oil and fat raw material used in the production of biodiesel, for the mixed fuel of biodiesel and light oil. To do.

  The present inventors previously invented the ozone treatment modifier using vegetable oil as a raw material instead of chemical synthesis, and the biodiesel derived from fats and oils containing a lot of unsaturated fatty acids has an excellent improvement effect on low-temperature fluidity. Although it can be obtained, biodiesel derived from fats and oils containing a large amount of saturated fatty acids has not been thought to provide the desired low-temperature fluidity improving effect. However, the inventors of the present application have conducted extensive research to increase the supply amount of biodiesel, and as a result, the addition amount of the ozone treatment modifier is 0.03 to 2.0% by weight. It has been found that excellent low-temperature fluidity can be obtained even with a biodiesel blend fuel derived from fats and oils with high saturated fatty acids.

  In the present invention, first, a mixed fuel for a diesel engine containing 0.03 to 2.0% by weight of a modifier obtained by ozone treatment of vegetable oil with respect to a mixed fuel containing at least biodiesel and light oil. I will provide a. By containing 0.03 to 2.0% by weight of the modifier with respect to the mixed fuel, the mixed fuel containing biodiesel and light oil can be flowed at low temperature regardless of the fatty acid composition of the fats and oils for producing biodiesel. It can be set as the mixed fuel excellent in property. The “vegetable oil” includes all substances containing at least a plant-derived oil.

  Next, in this invention, the said biodiesel provides the mixed fuel for diesel engines which is a biodiesel obtained from the fats and oils containing 10 weight% or more of saturated fatty acids. In particular, mixed fuel containing biodiesel produced from fats and oils with a high content of saturated fatty acids has room for improvement in low-temperature fluidity, but in the present invention, even such mixed fuel has excellent low-temperature fluidity. Or mixed fuel. “Oil and fat” includes all substances containing at least fat and oil regardless of animals and plants.

  In addition, the present invention lowers the pour point by adding 0.03-2.0% by weight of a modifier obtained by ozone treatment of vegetable oil with respect to a mixed fuel containing at least biodiesel and light oil. Provide a method. By making the addition concentration of the modifier 0.03-2.0% by weight, the pour point of the mixed fuel can be effectively reduced regardless of the fatty acid composition of the fats and oils for producing biodiesel. . The “pour point” refers to the lowest temperature at which the sample flows when the sample is cooled to 45 ° C. and then cooled. The pour point is measured according to JIS K 2269.

  According to this invention, it can be set as the mixed fuel which has the outstanding low-temperature fluidity | liquidity.

  Hereinafter, a preferred embodiment of a mixed fuel for diesel engines (hereinafter referred to as “mixed fuel”) according to the present invention will be described. Note that the following is merely an example of a typical embodiment of the mixed fuel according to the present invention, and the scope of the present invention is not construed narrowly.

  The mixed fuel of the present invention is a fuel to which a diesel engine fuel modifier (hereinafter referred to as “ozone treatment modifier”) obtained by subjecting vegetable oil to ozone treatment is added. The ozone treatment modifier can be produced, for example, by ozone treatment by a method such as aeration of vegetable oil with an ozone / oxygen mixed gas.

  The pour point depressing action of the fuel modifier is considered to be related to the number of unsaturated double bonds in the vegetable oil that is the raw material of the fuel modifier. Sunflower oil, linseed oil, rapeseed oil, safflower oil It is desirable to be an ozone treatment modifier using vegetable oils with many unsaturated double bonds such as corn oil, soybean oil, and cottonseed oil as raw materials.

  In the present invention, the effect on the pour point of the mixed fuel is not clear, but at least the degree of ozonide formation in the unsaturated double bond of the triglyceride contained in the ozone treatment modifier is important for the mechanism of action. It is thought that it is having an influence.

  Therefore, the ozone treatment modifier can also be obtained by performing ozone treatment on an artificially synthesized triglyceride having many unsaturated double bond sites. Examples of the modifier that can be used in the present invention include the modifiers described in PCT International Publication No. WO2005 / 033252.

  According to the present invention, by adding 0.03-2.0% by weight of the ozone treatment modifier to a mixed fuel of biodiesel and light oil, regardless of the fatty acid composition of the oil and fat raw material used for the production of biodiesel, A mixed fuel having excellent low-temperature fluidity can be obtained. That is, the inventors of the present invention surprisingly do not add the ozone treatment modifier to the mixed fuel, but surprisingly, by adding a trace amount of 0.03 to 2.0% by weight, biodiesel and light oil The present inventors have newly found that the pour point of the mixed fuel decreases, and have completed the present invention based on this finding.

  There are no particular limitations on the type of raw oil and fat of the biodiesel, and for example, vegetable oils such as rapeseed oil, sunflower oil, palm oil, and soybean oil, various animal oils and fats, waste cooking oil, and the like can be used. That is, not only fats and oils with a high content of unsaturated fatty acids but also fats and oils with a high content of saturated fatty acids can be used. As described above, in the present invention, since a wide variety of fats and oils can be used as the raw material for biodiesel, it is possible to cope with the recent increase in demand for biodiesel.

  In particular, biodiesel, which is a fat raw material with a saturated fatty acid content of 10% by weight or more, has insufficient low-temperature fluidity, and it is difficult to obtain sufficient low-temperature fluidity even with a mixed fuel mixed with light oil. However, in the present invention, even with such fats and oils, the desired effect can be obtained, so that fats and oils having a high saturated fatty acid content can also be used. That is, even biodiesel obtained from such fats and oils can be used as a practical mixed fuel by mixing with light oil and further adding 0.03-2.0% by weight of an ozone treatment modifier.

  Examples of fats and oils containing 10% by weight or more of saturated fatty acids include palm oil, soybean oil, cottonseed oil, rice oil, jatropha oil (oil taken from nanyo aburagiri), and the like. According to the present invention, a desired pour point depressing action can be obtained even in a mixed fuel containing biodiesel produced from fats and oils containing 10% by weight or more of such saturated fatty acids.

  The lower limit of the addition amount of the ozone treatment modifier in the present invention is 0.03% by weight or more, preferably 0.05% by weight or more with respect to the mixed fuel. Further, the upper limit of the addition amount of the ozone treatment modifier is desirably 2.0% by weight or less, and more desirably 1.5% by weight or less.

  Moreover, it does not specifically limit about the manufacturing method etc. of biodiesel, For example, it can manufacture by performing transesterification with an alkali catalyst, an acid catalyst, a lipase enzyme, etc. For example, methyl esterified fuel (FAME), which is widely used as biodiesel, is refined by methyl esterification by transesterification of fats and oils and methanol.

  In the present invention, the composition of the light oil is not particularly limited, and for example, commercially available light oil can be used as it is. The light oil may or may not contain a pour point depressant for light oil. Furthermore, the kind of the pour point depressant for light oil is not particularly limited. For example, commercially available light oil containing a pour point depressant for light oil can be mixed and used as it is. The pour point depressant for light oil may contain, for example, an ethylene-vinyl acetate copolymer (EVA). Moreover, in this invention, unless the effect of this invention is inhibited, mixed components other than light oil and biodiesel, and various additives can be used.

  Moreover, in this invention, it can be set as the mixed fuel excellent in low-temperature fluidity | liquidity, without adding the chemical synthesis additive for light oil, biodiesel, etc. to the said mixed fuel separately. The ozone treatment modifier used in the present invention contains almost no sulfur in the modifier itself, and is a renewable environment-friendly additive for vegetable oil raw materials. It is possible to make a mixed fuel that is easier to the environment.

  A pour point lowering method for a mixed fuel containing at least biodiesel and light oil will be described. By making the addition concentration of the ozone treatment modifier 0.03 to 2.0% by weight, the pour point of the mixed fuel of biodiesel and light oil can be lowered. That is, according to the present invention, the pour point can be easily lowered with respect to the mixed fuel whose pour point is increased by mixing biodiesel with commercially available light oil or the like. The pour point of the mixed fuel according to the present invention is preferably −20 ° C. or less from the viewpoint of a practical diesel engine fuel.

  Thus, according to the mixed fuel and the pour point depressing method according to the present invention, a mixed fuel excellent in low-temperature fluidity can be obtained regardless of the fatty acid composition of the fat and oil raw material used for the production of biodiesel.

  Hereinafter, an experiment was conducted for the purpose of verifying that the mixed fuel of biodiesel and light oil according to the present invention is excellent in low-temperature fluidity.

<Experiment 1>
"Effect of pour point improver on blended fuel of biodiesel and light oil derived from palm oil"

[Fuels used]
In Experiment 1, palm oil was used as a representative example containing 10% by weight or more of saturated fatty acids. First, palm oil biodiesel manufactured from palm oil was manufactured as biodiesel. Low temperature flow of mixed fuel by adding ozone treatment modifier and chemically synthesized gas oil and biodiesel pour point improver to mixed fuel mixed with 5% by volume of palm oil biodiesel produced in No. 2 diesel oil The best way to improve the performance was investigated.

[Production of biodiesel]
First, biodiesel was produced by the following procedure. Palm oil was methylesterified to obtain biodiesel.
In the methyl esterification reaction, a mixture of methanol (molar ratio; oil: methanol = 1: 10) and sodium hydroxide (0.5% oil weight) is added to palm oil, and the temperature is in the range of 60 to 70 ° C. The mixture was stirred and reacted for 1 hour. After completion of the reaction, the reaction solution was allowed to stand overnight, and the methyl ester layer was separated and recovered. The methyl ester layer was subjected to acid washing and water washing after centrifugation. And biodiesel was refine | purified by heating to 120 degreeC and deoxidizing and dehydrating.
The amount of saturated fatty acid of the obtained palm oil biodiesel was 44%.

[Ozone treatment modifier]
The ozone treatment modifier added to the fuel was prepared by ozone treatment of sunflower oil. 50 mL of sunflower oil was aerated with ozone / oxygen mixed gas (ozone gas concentration 40 g / Nm ³ , gas flow rate 0.5 L / min) at a reaction temperature of 20 to 40 ° C. When the reaction ozone amount reached 0.14 g-O ₃ / mL-oil and a theoretical reaction rate of 100%, ozone aeration was stopped and the reaction was terminated.

[Light oil]
Light oil is available from Kyokuto Petroleum Industries, Ltd., No. 2 light oil (pour point −4 ° C.) before adding the pour point improver for light oil and winter oil light oil (pour point −25 ° C.) after the addition. I got the type.

[Test method]
5% by volume of palm oil biodiesel was mixed with No. 2 light oil or light oil for winter sale containing a pour point improver for light oil to prepare a mixed fuel.
In Examples 1 and 2, an ozone treatment modifier was added to a mixed fuel using No. 2 light oil or light oil for winter sales. As comparative examples, No. 2 diesel oil mixed fuel (Comparative Example 1), 3 types of chemical synthesis pour point improvers for biodiesel in the mixed fuel of Comparative Example 1: CHIMEC 6635 (Comparative Example 2), Clariant Dodiflow 5305 (Comparison) Example 3) and R488 manufactured by Infineum (Comparative Example 4) were added respectively. In addition, the three types of chemical synthesis pour point improvers for biodiesel (Comparative Examples 6 to 8) were added to the light oil mixed fuel for winter sales (Comparative Example 5) and the mixed fuel of Comparative Example 5, respectively.
The pour point of each mixed fuel was measured and the low temperature fluidity was compared. The pour point depression measurement was performed in accordance with JIS K 2269. As an analytical instrument, Tanaka Scientific Instruments Manufacturing Co., Ltd. pour point / cloud point tester MPC101A was used. The results are shown in Table 1.

[Discussion]
A mixed fuel prepared by mixing 5% by volume of palm oil biodiesel with No. 2 diesel oil has a high pour point of −8 ° C. (Comparative Example 1). When the pour point improving agent for biodiesel chemically synthesized to the mixed fuel is added (Comparative Examples 2 to 4), the pour point of the mixed fuel can be lowered to around -20 ° C. On the other hand, when the ozone treatment modifier is added, it becomes possible to further lower the pour point of the mixed fuel by −10 ° C. or more as compared with the comparative example.
In addition, in the case of mixed diesel oil of diesel oil for winter sales (pour point -25 ° C) containing pour point improver for diesel oil and 5% by volume palm oil biodiesel, the pour point is -18 ° C, and the pour point is reduced by mixing biodiesel. Increased (Comparative Example 5). This shows that the pour point improving agent for light oil has no effect on the mixed fuel with palm oil biodiesel. When a chemically synthesized pour point improver for biodiesel (Comparative Examples 6 to 8) is added to this mixed fuel, the pour point can only be lowered to −25 ° C., but when an ozone treatment modifier is added. (Example 2) Further, the pour point could be lowered and lowered to -30 ° C or lower. This is also the ozone treatment modifier compared to the commercially synthesized pour point improver that is also commercially available for fuels that are mixed with biodiesel in light oil for winter sale to which the pour point improver for light oil is added. Is very good at lowering the pour point.

  From the above results, from the results of this Example, regardless of the presence or absence of a pour point improver for light oil, the ozone treatment modifier is very excellent in the pour point depressing effect on the mixed fuel of light oil and palm oil biodiesel, Compared with the chemical synthesis pour point improver of In addition, the pour point can be sufficiently lowered only by the ozone treatment modifier.

<Experiment 2>
"Effect of addition of ozone treatment modifier on blended fuel of biodiesel and light oil derived from palm oil or soybean oil"

  An ozone treatment modifier was added to a blended fuel in which palm oil or soybean oil biodiesel was mixed with No. 2 diesel oil, and the effect was examined. We investigated how far the proportion of biodiesel in the blended fuel can be increased by the ozone treatment modifier.

[Light oil, biodiesel, pour point improver]
No. 2 light oil was used as the light oil. Biodiesel was produced from palm oil and soybean oil in the same manner as in Experiment 1. The obtained palm oil biodiesel had a saturated fatty acid content of 44% and soybean oil biodiesel 14%. Similarly, sunflower oil was treated with ozone to synthesize an ozone treatment modifier.

[Test method]
Each biodiesel was mixed with No. 2 diesel oil at a rate of 5 to 80% by volume to prepare a mixed fuel. The ozone treatment modifier was added to the mixed fuel, and the pour point was measured as in Experiment 1. The results are shown in Tables 2 and 3.

[Discussion]
About the mixed fuel which mixed palm oil biodiesel with No. 2 light oil, when the ratio of palm oil biodiesel in mixed fuel was raised, the pour point increased (Comparative Examples 1, 9 to 11). When 0.5% by weight of an ozone treatment modifier that is excellent as a pour point improver for mixed fuel is added, the pour point can be reduced to −30 ° C. or less even with 10% by volume of palm oil biodiesel mixed fuel (Example) 3) The pour point could be maintained at −20 ° C. even with 20% by volume of palm oil biodiesel mixed fuel (Example 4). And in the fuel which mixed palm oil biodiesel 30 volume%, the pour point of the mixed fuel which does not add an ozone treatment modifier was -3 degreeC (comparative example 11), whereas an ozone treatment modifier is used. The pour point when added was −4 ° C. (Example 5). From this result, it was suggested that a mixed fuel or the like obtained by mixing 20 vol% of palm oil biodiesel with No. 2 light oil can be used in winter by using an ozone treatment modifier.

  Moreover, also in the case of soybean oil biodiesel, like the palm oil biodiesel mixed fuel, when the mixing ratio of biodiesel was increased, the pour point increased (Comparative Examples 12 to 16). When 0.5% by weight of the ozone treatment modifier was added thereto, the pour point could be maintained at around -30 ° C. even with 40% by volume of soybean oil biodiesel mixed fuel (Examples 6 to 8). In the case of 60% by volume of soybean oil biodiesel mixed fuel, the pour point decreased to −23 ° C. even when an ozone treatment modifier was added (Example 9), and in the case of 80% by volume mixed fuel, the pour point was −12 ° C. (Example 10). From these results, it was suggested that the mixed fuel or the like obtained by mixing 60% by volume of soybean oil biodiesel with No. 2 light oil can be used in winter by using the ozone treatment modifier.

  From the above, according to the results of this example, palm oil and soybean oil biodiesel having a high pour point and poor low-temperature fluidity because they contain a lot of saturated fatty acids are mixed with light oil, and an ozone treatment modifier is added at a predetermined concentration. It was possible to dramatically reduce the pour point and to increase the proportion of biodiesel in the mixed fuel. This suggests that, for example, even if the amount of biodiesel is increased to a rate that is not normally possible in winter, it can be used.

<Experiment 3>
“Examination of the minimum amount of ozone treatment modifier added to blended fuel of biodiesel and diesel oil derived from palm oil or soybean oil”

[Fuels used]
In Experiment 3, 5% by volume of palm oil or soybean oil biodiesel was mixed with light oil for winter sale containing a pour point improver for light oil to prepare a mixed fuel. An ozone treatment modifier was added to this mixed fuel, and the lower limit addition amount was examined. The palm oil or soybean oil biodiesel and the ozone treatment modifier used in the test were prepared in the same manner as in Experiment 1. The results are shown in Table 4.

[Discussion]
A mixed fuel of 5% by volume palm oil biodiesel and light oil for winter sale has a pour point of −18 ° C. (Comparative Example 5). When 0.05% by weight of the ozone treatment modifier was added to this mixed fuel, the pour point slightly decreased and was −19 ° C. (Example 11). When 0.06% by weight of the ozone treatment modifier was added, the pour point was further lowered to −22 ° C. (Example 12), and when 0.2% by weight was added, the pour point could be lowered to −35 ° C. (Example 14). ).

  Moreover, the pour point of the mixed fuel of soybean oil biodiesel and light oil for winter sales was −25 ° C. (Comparative Example 17). When 0.03% by weight of the ozone treatment modifier was added to this mixed fuel, the pour point slightly decreased and was −26 ° C. (Example 15). When 0.04 wt% of the ozone treatment modifier was added, the pour point was further lowered to −28 ° C. (Example 16), and when 0.05 wt% was added, the pour point could be lowered to −30 ° C. (Example 17). ).

  As described above, from the results of this experiment, the lower limit addition amount of the ozone treatment modifier in the mixed fuel of the present invention is 0.03% by weight or more from the result of the mixed fuel of soybean oil biodiesel and light oil for winter sale, Preferably it was 0.05% by weight or more.

<Experiment 4>
“Examination of the upper limit addition amount of ozone treatment modifier to blended fuel of biodiesel and light oil derived from palm oil or soybean oil”

[Fuels used]
In Experiment 4, a blended fuel was prepared by mixing 5% by volume of palm oil or soybean oil biodiesel with No. 2 diesel oil. An ozone treatment modifier was added to this mixed fuel, and the upper limit addition amount was examined. The palm oil or soybean oil biodiesel and the ozone treatment modifier used in the test were prepared in the same manner as in Experiment 1. The results are shown in Table 5.

[Discussion]
The mixed fuel of 5% palm oil biodiesel and No. 2 diesel oil has a pour point of −8 ° C. (Comparative Example 1). When 0.5% by weight of the ozone treatment modifier was added to this mixed fuel, the pour point was the lowest and was −34 ° C. (Example 1). When 1.0 wt% of the ozone treatment modifier was added, the pour point became -21 ° C (Example 18), and when 1.5 wt% was added, the pour point rose to -19 ° C (Example 19).

  Moreover, the pour point of the mixed fuel of soybean oil biodiesel and No. 2 diesel oil was −5 ° C. (Comparative Example 12). When 0.5% by weight of the ozone treatment modifier was added to this mixed fuel, the pour point was the lowest and was −33 ° C. (Example 6). When 2.0 wt% of the ozone treatment modifier was added, the pour point rose to −22 ° C. (Example 22), and when 1.5 wt% was added, it became −19 ° C. (Example 23).

  From the viewpoint of making a practical diesel engine fuel, the pour point is desirably -20 ° C or lower. From the above results, from the results of this experiment, the lower limit addition amount of the ozone treatment modifier in the mixed fuel of the present invention is 2.0% by weight or less, preferably from the results of the mixed fuel of soybean oil biodiesel and No. 2 diesel oil. Was shown to be 1.5 wt% or less.

  The mixed fuel for diesel engines according to the present invention can be widely used as a fuel used for vehicles, various engines and the like.

Claims (3)

  A diesel engine mixed fuel containing 0.03 to 2.0% by weight or less of a modifier obtained by ozone treatment of vegetable oil with respect to a mixed fuel containing at least biodiesel and light oil.   The mixed fuel for diesel engines according to claim 1, wherein the biodiesel is obtained from fats and oils containing 10% by weight or more of saturated fatty acids.   A method of lowering the pour point by adding 0.03 to 2.0% by weight of a modifier obtained by ozone treatment of vegetable oil with respect to a mixed fuel containing at least biodiesel and light oil.