JP2010013511A - Biodiesel fuel and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a biodiesel fuel which neither uses vegetable oils conventionally distributed as food materials or industrial materials such as cereal grains such as corn, palm oil, and coconut oil, nor disturbs the distribution order of plant resources; and to provide a method for producing the same. <P>SOLUTION: The biodiesel fuel contains a methyl ester of fatty acids derived from Xanthoceras sorbifolia Bunge. The method for producing the biodiesel fuel includes a sampling step of sampling vegetable oils from the seed of Xanthoceras sorbifolia Bunge, an esterification step of carrying out transesterification by adding methanol to the vegetable oils in the presence of an acid or basic catalyst, and a dividing step of dividing a methyl ester of fatty acids from the reaction liquid of the esterification step. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a biodiesel fuel and a method for producing the same. More specifically, biodiesel fuel that does not disturb the distribution order of plant resources without using cereals such as corn, vegetable oils that have been distributed as edible raw materials and industrial raw materials such as palm oil and coconut oil, and It relates to the manufacturing method.

  In recent years, the problem of global warming due to an increase in carbon dioxide, which is a greenhouse gas in the atmosphere, has become apparent, and various measures such as reduction of greenhouse gases and prevention of desertification are being taken by the Kyoto Protocol. Under these circumstances, biodiesel derived from cereal-derived bioethanol (Patent Document 1), palm oil, coconut oil, and the like as biofuels to replace fossil fuels that are said to be depleted in over a decade. Development and production of fuels (Patent Documents 2 and 3) are in progress.

JP 2004-155875 A JP 2004-359766 A JP 2007-277288 A

  However, the above-mentioned conventional biofuels are made from cereals that are widely distributed for edible use, and animal and vegetable oils that are widely distributed for edible and industrial use. Has brought about soaring. Furthermore, there are problems such as desertification due to deforestation to secure the acreage.

  The present invention was made in order to solve the above-mentioned conventional problems, without using cereals such as corn, and vegetable oils that are conventionally distributed as edible raw materials and industrial raw materials such as palm oil and coconut oil, An object of the present invention is to provide a biodiesel fuel that does not disturb the distribution order of plant resources and a method for producing the same.

  In order to solve the above-mentioned problems, the inventors paid attention to Xanthoceras sorbifolia Bunge of Sapindaceae as a new raw material for biodiesel fuel. Bunkanka seeds contain oil as much as 25% of its weight, and this content is unmatched by other plants, so it is extremely excellent as a raw material for biodiesel fuel. Bunkanka is also resistant to cold, devastated and dry soils, and can contribute to desert greening. As a result of further earnest research, the present inventors have found that the above problems can be solved by containing methyl ester of a fatty acid derived from Bunkanka as biodiesel fuel, and the present invention has been completed.

  That is, the biodiesel fuel of the present invention is characterized by containing a methyl ester of a fatty acid derived from Bunkanka.

  In the biodiesel fuel of the present invention, bunkanka is used as a plant resource without using cereals such as corn, and vegetable oils that have been circulated as edible raw materials and industrial raw materials such as palm oil and coconut oil. A fatty acid triglyceride contained in bunkanka seeds that has been methyl esterified by transesterification is excellent in low-temperature fluidity and can be used as a diesel fuel.

  In the biodiesel fuel of the present invention, it is preferable that a viscosity modifier is further added. This is because the low temperature fluidity in a cold region is further improved.

  The biodiesel fuel of the present invention can be obtained by transesterifying a vegetable oil collected from the seeds of Bunkanka into a methyl ester. That is, the method for producing biodiesel fuel of the present invention includes a collecting step of collecting vegetable oil from a seed of bunkanka, an esterification step of adding methanol to the vegetable oil and performing transesterification in the presence of an acid catalyst or a basic catalyst, And a fractionation step of fractionating a fatty acid methyl ester from the reaction solution of the esterification step.

  When a basic catalyst is used as the catalyst in the esterification step, it is preferable to add the basic compound after adding methanol first to complete methyl esterification of the free fatty acid. If it is like this, it is because the production | generation of the soap which arises from the neutralization reaction of the free fatty acid contained in vegetable oil and a basic compound can be avoided, and smoothening of transesterification can be aimed at.

  Furthermore, if a viscosity modifier is added, since the low temperature fluidity | liquidity in a cold region improves further, a more suitable biodiesel fuel can be manufactured.

  In the esterification step, microwave heating can also be used. Microwave heating refers to internal heat generated by rotation and vibration of an electric dipole within a molecule generated by microwaves. By microwave heating, energy can be directly given to the molecule, and the esterification reaction can be performed more rapidly.

  It is also preferable to perform the esterification step under conditions of 100 ° C. or higher and 1 atmosphere or higher. If it is like this, esterification can be performed further rapidly.

(Embodiment)
Hereinafter, an embodiment of the present invention will be described with reference to FIG.

(Collecting process S1)
First, as a collecting step S1, bunkanka crude oil is collected by squeezing and / or extracting from bunkanka seeds. Furthermore, bunkanka refined oil having a relatively high degree of purification can be obtained by degumming the Bunkanka crude oil by filtration or the like, separating oil components, and decolorizing and deodorizing using deoxidation, activated clay, activated carbon and the like. Further, by cooling the bunkanka crude oil or the bunkanka refined oil, the solid component can be removed, and a bunkanka highly refined oil having a further improved degree of purification can be obtained. As a vegetable oil used as a raw material for biodiesel fuel production, Bunkanka crude oil, Bunkanka refined oil, and Bunkanka highly refined oil can be used alone or in combination.

(Esterification step S2)
Next, as the esterification step S2, a transesterification reaction is performed between vegetable oil derived from bunkanka and methyl alcohol in the presence of an acidic catalyst or a basic catalyst. Thereby, the fatty acid triglyceride and free fatty acid contained in vegetable oil are converted into fatty acid methyl ester.

  Examples of the compound that can be used as the acidic catalyst include concentrated sulfuric acid, sulfuric acid, concentrated hydrochloric acid, hydrochloric acid, sulfonic acid, solid acid catalyst (metal oxide, zeolite, ion exchange resin, etc.) and the like. Of these, concentrated sulfuric acid, concentrated hydrochloric acid, sulfonic acid and solid acid catalyst are preferred. The addition amount of the acidic catalyst is not particularly limited as long as it is an amount capable of converting a fatty acid into a desired methyl ester, and may be appropriately adjusted according to reaction conditions such as temperature, but with respect to the total amount of the mixture of vegetable oil and methyl alcohol. 0.5 to 1% by mass is preferable. The temperature of the transesterification reaction is not particularly limited as long as it is a temperature at which a fatty acid can be converted into a desired methyl ester, but is preferably 110 to 160 ° C. What is necessary is just to set suitably about reaction time and other reaction conditions so that it may become the conditions which can convert a fatty acid into desired methyl ester.

  In addition, when the transesterification reaction is performed using a basic catalyst, the free fatty acid contained in the vegetable oil in advance is converted to the methyl ester using methyl alcohol in the presence of an acidic catalyst such as sulfuric acid, and then the transesterification reaction is performed. It is desirable to do. This is because when a basic catalyst is added with the free fatty acid remaining, a salt of fatty acid (ie, soap) is formed, and subsequent smooth esterification reaction becomes difficult. Examples of the basic catalyst include hydroxides such as sodium hydroxide and potassium hydroxide, alkoxides such as sodium methoxide and potassium methoxide, and known basic catalysts such as a solid base catalyst. Sodium is preferred. The addition amount of the basic catalyst may be determined as appropriate so that the fatty acid can be converted into the desired methyl ester, but is based on the total amount of the mixture of vegetable oil (pre-free fatty acid methyl esterified) and methyl alcohol. 0.3 to 1% by mass is preferable. The transesterification reaction temperature is not particularly limited as long as it is a temperature at which a fatty acid can be converted into a desired methyl ester, and known conditions can be used, but 50 ° C to 60 ° C is usually preferable. The reaction time and other reaction conditions are not particularly limited as long as the fatty acid can be converted into a desired methyl ester, and may be appropriately determined.

(Preparation process S3)
Finally, as the fractionation step S3, the fatty acid methyl ester produced in the esterification step S2 is fractionated. The sorting method is not particularly limited as long as a desired fatty acid methyl ester can be sorted, and a known sorting method can be used. For example, from the reaction mixture of the transesterification reaction, the produced glycerin is separated and removed by natural separation or centrifugal separation using the specific gravity difference, and then washed with water or a neutralizing agent, and the fatty acid methyl ester layer Get. By subjecting this fatty acid methyl ester layer to other known methods such as heat treatment, the moisture can be removed and used as it is as a biodiesel fuel, and a fatty acid methyl ester having preferable low-temperature fluidity can be obtained. Further, by subjecting the fatty acid methyl ester layer (including those from which the water has been removed) to known purification operations such as fractional distillation and crystallization, it can be used as biodiesel fuel and more preferably has low-temperature fluidity. The fatty acid methyl ester having can be obtained. Here, the low temperature fluidity means that the pour point of the fatty acid methyl ester measured by the test method specified in JIS K2269.3 is 15 ° C. or less, and the preferred low temperature fluidity means that the pour point is 5 ° C. The more preferable low-temperature fluidity means that the pour point is −5 ° C. or lower.

  In addition, it is also preferable to mix a viscosity modifier as needed with respect to the biodiesel fuel obtained by fractionation process S3 (viscosity adjustment process S4). By mixing a viscosity modifier with the biodiesel fuel, its low-temperature fluidity can be further improved. The viscosity modifier is not particularly limited as long as it can improve the pour point of fatty acid methyl ester to a desired pour point, and a known viscosity modifier can be used. For example, polyalkyl methacrylate (PMA) , Polyacrylate (PA), alkylated aromatic compound, fumarate-vinyl acetate copolymer, ethylene-vinyl acetate copolymer (EVA), and known compounds such as alcohols. Among these, PMA, EVA An aliphatic alcohol having 3 to 5 carbon atoms is preferred. The addition amount of the viscosity modifier is not particularly limited as long as it can improve the pour point of the fatty acid methyl ester to a desired pour point, and a known addition amount can be used. To 0.1 parts by weight for PMA, 0.5 to 1.5 parts by weight for EVA, and 10 to 25 parts by weight for aliphatic alcohols having 3 to 5 carbon atoms Is preferably added.

Hereinafter, the present invention will be specifically described by way of examples.
(Collection process)
25 kg of bunkanka crude oil was obtained from 100 kg of bunkanka seeds using a press. This bunkanka crude oil was filtered, and deoxidation and deodorization using activated carbon were performed to obtain 20 L of bunkanka oil.

(Esterification process)
-Acid transesterification process-
To 10 L of bunkanka oil and 2 L of methyl alcohol, 0.5% by mass of concentrated sulfuric acid was added, heated to 160 ° C. with a mantle heater, and esterified for 4.5 hours. The reaction mixture was washed with water and dried until the aqueous layer became neutral to obtain 12 L of fatty acid methyl ester. The ester exhibited a pour point of 40 ° C. according to the test method specified in JIS K2269-3.

-Basic transesterification step-
Add 10 mL of concentrated sulfuric acid to 10 L of bunkanka oil and 0.8 L of methyl alcohol, heat and stir at 35 ° C. for 1 hour, stop heating, stir for 1 hour, and then stand for 8 hours to convert the free fatty acid to methyl ester .

A solution prepared by dissolving 35 g of sodium hydroxide in 1.2 L of methanol in advance was added to the reaction mixture while stirring at room temperature, and the mixture was stirred at 55 ° C. for 2 hours while removing glycerol formed in the lower layer. Thereafter, the mixture was allowed to stand for 1 hour, glycerin produced in the lower layer was removed, and the upper layer (fatty acid methyl ester) was washed with 4 L of water and dried. The ester exhibited a pour point of 40 ° C. according to the test method specified in JIS K2269.3.

  In the above embodiment, the esterification is performed by heating under normal pressure, but a microwave heating method may be applied. That is, the esterification of the above embodiments can also be performed by a continuous liquid feeding system in a microwave reactor including a heating unit such as a microwave oscillator, a reaction vessel for esterification, a waveguide, and an antenna. As a result, it is possible to shorten the reaction time by significantly reducing the time to reach the desired reaction temperature, reduce the environmental load by improving energy efficiency, and prevent reaction unevenness by uniform and continuous heating.

  It is also preferable to carry out the esterification step in an autoclave at a temperature of 100 ° C. or higher. If it is like this, esterification can be performed further rapidly.

  The present invention is not limited to the description of the embodiment of the invention. Various modifications may be included in the present invention as long as those skilled in the art can easily conceive without departing from the description of the scope of claims.

It is process drawing which shows the manufacturing method of the biodiesel fuel in embodiment.

Explanation of symbols

S1 ... Collection step S2 ... Esterification step S3 ... Preparative step S4 ... Viscosity adjustment step

Claims (6)

  A biodiesel fuel characterized by containing a methyl ester of a fatty acid derived from Xanthoceras sorbifolia Bunge (Xanthoceras sorbifolia Bunge).   The biodiesel fuel according to claim 1, wherein a viscosity modifier is added.   A sampling step for collecting vegetable oil from the seeds of Bunkanka, an esterification step in which methanol is added to the vegetable oil and transesterification is performed in the presence of an acid catalyst or a basic catalyst, and a methyl ester of a fatty acid from the reaction solution of the esterification step A method for producing biodiesel fuel, comprising a fractionation step of fractionating the fuel.   5. The method for producing biodiesel fuel according to claim 3, further comprising a viscosity adjusting step of adding a viscosity adjusting agent to the fatty acid methyl ester obtained in the preparative step.   The method for producing biodiesel fuel according to claim 3 or 4, wherein microwave heating is used in the esterification step.   The method for producing biodiesel fuel according to claim 3 or 4, wherein the esterification step is performed at 100 ° C or higher and under pressure.

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