JP2009067904A - Method for producing fatty acid methyl ester, fatty acid methyl ester, and biodiesel fuel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new manufacturing method for a fatty acid methyl ester, a fatty acid methyl ester manufactured by the method, and a bio-diesel fuel containing the fatty acid methyl ester. <P>SOLUTION: In the manufacturing method for the fatty acid methyl ester, a step for reacting fats and oils, methanol and calcium hydroxide or calcium oxide is performed, and an amount of methanol in the reaction step is used in an amount such that the reaction mixture after the reaction step is separated to two layers, a main component of an upper layer is methanol, and the upper layer becomes transparent. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a fatty acid methyl ester, a fatty acid methyl ester, and a biodiesel fuel.

  Fatty acid methyl esters obtained by subjecting fatty acid glycerides contained in vegetable oils and fats, used waste cooking oils, animal oils, fish oils and the like to transesterification with methanol can be effectively used as diesel fuel. For this reason, fatty acid methyl esters are attracting attention as low-environmental impact biodiesel fuels that can replace petroleum fuels, and many approaches have been studied so far regarding their production methods.

As an example of the production method, there is a method using calcium hydroxide (Ca (OH) ₂ ) or calcium oxide (CaO) as a catalyst. However, when these catalysts are used, there is a problem that the calcium component remains in the product fatty acid methyl ester.
In particular, when fatty acid methyl esters are used as biodiesel fuel, there is a strict European standard for the total content of calcium and magnesium components that must be less than 5 ppm in terms of metal component content. In order to remove the calcium component to be removed, it was necessary to subject the fatty acid methyl ester to a water washing treatment, and to perform a dehydration treatment using an adsorbent in order to remove the water contained by the water washing treatment.

  Then, an object of this invention is to provide the novel manufacturing method of fatty acid methyl ester with few calcium component content, the fatty acid methyl ester manufactured by this method, and the biodiesel fuel containing this fatty acid methyl ester.

  In the reaction system of the transesterification reaction between oil and fat and methanol using calcium hydroxide or calcium oxide as a catalyst, the present inventor separated the amount of methanol into two layers by the reaction mixture after the transesterification reaction. When the main component of the upper layer is methanol and the upper layer is used so as to be transparent, it has been found that the amount of calcium component contained in the product fatty acid methyl ester is drastically reduced. Completed.

That is, the present invention is as follows.
(I) A method for producing a fatty acid methyl ester, comprising a step of reacting fats and oils, methanol, calcium hydroxide or calcium oxide, and the mixed solution after the reaction step is separated into two layers, The method according to claim 1, wherein the component is methanol and the methanol in the reaction step is used in such an amount that the upper layer becomes transparent.

  (Ii) A method for producing a fatty acid methyl ester, comprising a step of reacting fats and oils, methanol and calcium hydroxide or calcium oxide, wherein the amount of the methanol converts the fats and oils into the fatty acid methyl esters. The production method is 10 times to 28 times the theoretical amount necessary for the production.

  (Iii) The method according to (ii), wherein the amount of the methanol is 20 times to 28 times the theoretical amount.

  (Iv) The production method according to (i) to (iii), wherein the reaction step is performed at 50 to 80 ° C.

  (V) The method according to any one of (i) to (iv), further comprising a step of purifying the fatty acid methyl ester by distillation, washing with water, an adsorbent containing activated carbon, or an ion exchange resin. Production method.

  (Vi) The production method according to any one of (i) to (v), wherein the fatty acid methyl ester is used as a biodiesel fuel.

  (Vii) A fatty acid methyl ester produced by the method according to any one of (i) to (vi).

  (Viii) A biodiesel fuel comprising the fatty acid methyl ester described in (vii).

  According to the present invention, it is possible to provide a novel method for producing a fatty acid methyl ester, a fatty acid methyl ester produced by this method, and a biodiesel fuel containing this fatty acid methyl ester.

  Hereinafter, embodiments of the present invention completed based on the above knowledge will be described in detail with reference to examples. The objects, features, advantages, and ideas of the present invention will be apparent to those skilled in the art from the description of the present specification, and those skilled in the art can easily reproduce the present invention from the description of the present specification. it can. The embodiments and specific examples of the invention described below show preferred embodiments of the present invention and are shown for illustration or explanation, and the present invention is not limited to them. It is not limited. It will be apparent to those skilled in the art that various modifications and variations can be made based on the description of the present specification within the spirit and scope of the present invention disclosed herein.

== Production method of fatty acid methyl ester ==
The fatty acid methyl ester according to the present invention reacts fats and oils, methanol, and calcium hydroxide or calcium oxide, and the amount of methanol used at this time is separated into two layers by the reaction mixture after the transesterification reaction. The main component of the subsequent upper layer is methanol, and the upper layer can be produced transparently (formula (1)).
For example, it can be produced by reacting oil and fat, methanol of not less than 10 times and not more than 28 times the theoretical amount necessary to convert the fat into fatty acid methyl ester, and calcium hydroxide or calcium oxide. good.

As fats and oils, triglycerides of fatty acids are described in the formula (1), but not limited thereto, and diglycerides, monoglycerides, or mixtures thereof can be used in addition to triglycerides of fatty acids.
The fats and oils used in the reaction may be naturally occurring fats and oils or synthesized fats and oils, and may be vegetable fats and oils, used waste cooking oils, animal fats and oils, or fish fats and oils. Further, for example, it may be a fat or oil that has been modified by oxidation or reduction due to oxygen or heat in the air, a fat or oil-derived waste, or a mixture thereof.
Specifically, corn oil, soybean oil, sesame oil, rapeseed oil, safflower oil (safflower oil), palm oil, palm kernel oil, palm oil, coconut oil, sunflower oil, olive oil, linseed oil (linseed oil), coconut Oil, oak oil, almond oil, peanut oil, avocado oil, hazelnut oil, walnut oil, grape seed oil, sardine oil, mackerel oil, shark oil, whale oil, liver oil, lard, beef tallow (chicken), chicken fat, butter fat , Cocoa butter fat, Schmalz, shortening, castor oil, or a mixture thereof, but is not limited thereto.

The amount of methanol to be used is such that when the mixture is allowed to stand after the transesterification reaction, the reaction mixture is separated into two layers, the main component of the upper layer after the separation is methanol, and the upper layer is transparent. The amount of calcium components contained in the product fatty acid methyl ester can be significantly reduced. Here, the upper layer being transparent means a clear state where fine particles are not dispersed in the liquid, and the color of the upper layer may be colorless or colored. The fact that the reaction mixture is separated into two layers having a transparent upper layer can be clearly determined by the naked eye, but the determination method is not limited to visual observation.
The amount of methanol to be used may be determined in advance by conducting a pilot experiment. For example, the amount of methanol to be used is in the range of 10 times to 28 times the theoretical amount necessary for converting fats and oils to fatty acid methyl esters. be able to. In particular, in order to easily obtain a fatty acid methyl ester in which the concentration of the calcium component in the fatty acid methyl ester is 5 ppm or less, it is preferably in the range of 20 times to 28 times the amount.

  The purity of calcium hydroxide and calcium oxide is not limited. Further, calcium hydroxide and calcium oxide may be used simultaneously.

The method of reacting oil and fat, methanol, calcium hydroxide or calcium oxide may be any method, for example, stirring, shaking, contact by spraying, and batch production by standing, Distribution type continuous production can be used, but is not limited thereto. Further, the order of contact is not particularly limited.
The temperature at which the transesterification reaction is carried out is not particularly limited, but is preferably 50 ° C. or higher from the viewpoint of the reaction rate. The pressure at which the transesterification reaction is carried out is not particularly limited, but is preferably normal pressure or higher.

== Purification method of fatty acid methyl ester ==
The fatty acid methyl ester produced by the above method can be easily separated from glycerin, which is a by-product, by a conventional method such as standing or centrifugation. Further, excess methanol is distilled off from the organic layer after separation of glycerin by a conventional method such as standing or centrifugation by a conventional method such as atmospheric distillation, vacuum distillation, spontaneous volatilization, or a combination thereof. Thus, the fatty acid methyl ester can be easily purified.
The distilled methanol can be used again for the reaction.

  The fatty acid methyl ester thus separated from glycerin, excess methanol and the like contains almost no calcium component derived from the catalyst, and can be used as it is for various applications as it is basically without further purification. Depending on the intended use, further purification may be performed by combining ordinary methods such as distillation, washing with water, filtration with an adsorbent such as activated carbon and ion exchange resin.

== Usage method of fatty acid methyl ester ==
Although the intended purpose of the fatty acid methyl ester produced or purified by the above method is not particularly limited, it can be used as, for example, biodiesel fuel.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, the scope of the present invention is not limited to the following Example.

[Example 1] Production of fatty acid methyl ester using vegetable oil and fat as raw material In a reaction system in which 2.2 g of calcium oxide was added to 100 g of plant-derived oil and fat containing abundant stearic acid, methanol was added to 15, 50, Transesterification was performed by adding 75, 100, 150, 200, 280, 290, 300 or 400 g and stirring at 60 ° C. for 45 minutes or more. The reaction mixture after the reaction was left standing and allowed to cool to room temperature.

== Measurement of calcium component concentration ==
About each said reaction mixture, the calcium component density | concentration contained in the fatty-acid methyl ester produced | generated with the following method was measured.

  When the reaction mixture was separated into two layers, the organic layer was first separated, and then methanol was distilled off from the resulting organic layer by distillation to obtain the desired fatty acid methyl ester as a residue. A part of the fatty acid methyl ester thus obtained was taken out and hydrolyzed by adding appropriate amounts of sulfuric acid and nitric acid sequentially using a reflux type decomposition apparatus. After removing the sulfuric acid and nitric acid by drying, the residue was extracted with an appropriate amount of hydrochloric acid. The extracted sample was measured by flame atomic absorption method (wavelength 422.7 nm, AA-11 manufactured by Nippon Jarrell Ash Co., Ltd.) according to JIS K0102 50.2.

  On the other hand, when the reaction mixture was not separated into two layers, methanol was distilled off under reduced pressure using an evaporator, and then the aqueous layer (glycerin layer) generated by the layer separation was separated and removed. A part of the fatty acid methyl ester thus obtained was taken out and hydrolyzed by adding appropriate amounts of sulfuric acid and nitric acid sequentially using a reflux type decomposition apparatus. After removing the sulfuric acid and nitric acid by drying, the residue was extracted with an appropriate amount of hydrochloric acid. The extracted sample was measured by flame atomic absorption method (wavelength 422.7 nm, AA-11 manufactured by Nippon Jarrell Ash Co., Ltd.) according to JIS K0102 50.2.

  Table 1 shows the measurement results of the calcium component concentration, the main components of the upper layer of the reaction mixture, and the turbidity of the upper layer.

== Result analysis ==
As Table 1 shows, even if the reaction mixture is separated into two layers, the upper layer is mainly composed of methanol (methanol amount 15 g, 1.5 times the theoretical amount necessary to convert fats and oils to fatty acid methyl esters) If applicable), if the reaction mixture does not separate into two layers (more than 50 g and 290 g of methanol, ie more than 5 times the theoretical amount and more than 29 times), and the reaction mixture is separated into two layers However, in any case where the upper layer is methanol, but the upper layer is not transparent (75 g of methanol, 7.5 times the theoretical amount), the calcium component contained in the produced fatty acid methyl ester The concentration was remarkably high, 200 ppm to 2000 ppm.

In contrast, the reaction mixture was separated into two layers, the main component of the upper layer was methanol, and the reaction using methanol in an amount such that the upper layer was transparent (amount of methanol 100 g to 280 g, Included in fatty acid methyl ester when the amount of methanol is 100 g (10 times the theoretical amount) and the theoretical amount required to convert fats and oils to fatty acid methyl ester is 10 to 28 times the theoretical amount The amount of calcium component decreased rapidly, and the concentration of calcium component showed a very low value of 14 ppm.
Furthermore, when 200 g to 280 g of methanol (20 to 28 times the theoretical amount) is used, the calcium component and An extremely pure fatty acid methyl ester of 3.9 ppm to 4.2 ppm could be obtained, which could meet the stringent European standard requirements for biodiesel fuel, where the total concentration of magnesium components must be less than 5 ppm.

  In addition, the reaction mixture was separated into two layers, the main component of the upper layer was methanol, and the amount obtained so that the upper layer was transparent was obtained by a reaction using methanol (methanol amount 100 g to 280 g). When the fatty acid methyl ester was further purified with a cation exchange resin (Amberlyst 15DRY, manufactured by Organo Corporation), the concentration of calcium components contained in the fatty acid methyl ester was not detected.

[Example 2] Manufacture of fatty acid methyl ester using animal fats and oils Lard, which is animal fats and oils, was used as a raw material to produce fatty acid methyl esters.
In a reaction system in which 2.2 g of calcium oxide is added to 100 g of lard, the reaction mixture is separated into two layers, the main component of the upper layer is methanol, and 100 or 200 g of methanol is added so that the upper layer is transparent, The transesterification reaction was carried out by stirring at 60 ° C. for 45 minutes or more. The reaction mixture after the reaction was left standing and allowed to cool to room temperature.

The calcium component concentration contained in the produced fatty acid methyl ester was measured according to the method described in Example 1.
Table 2 shows the measurement results of the calcium component concentration, the main components of the upper layer of the reaction mixture, and the turbidity of the upper layer.

  As shown in Table 2, even when animal fats and oils are used as raw materials, the reaction mixture is separated into two layers as in Example 1 using vegetable fats and oils as a raw material, and the main component of the upper layer is methanol. In addition, if the transesterification reaction is performed using methanol in such an amount that the upper layer is transparent, the calcium component concentration can be obtained by performing a very simple post-treatment such as stationary separation of the reaction mixture and distillation of the methanol. However, it was possible to obtain a fatty acid methyl ester having a purity of only 5.4 to 15 ppm.

Claims (8)

A method for producing a fatty acid methyl ester, comprising a step of reacting fats and oils, methanol, calcium hydroxide or calcium oxide,
The reaction mixture after the reaction step is separated into two layers, and the main component of the upper layer is methanol, and methanol in the reaction step is used in such an amount that the upper layer becomes transparent.   A method for producing a fatty acid methyl ester, comprising a step of reacting fats and oils, methanol, and calcium hydroxide or calcium oxide, wherein the amount of methanol is necessary for converting the fats and oils into the fatty acid methyl esters. The production method, which is 10 times to 28 times the theoretical amount.   The method according to claim 2, wherein the amount of the methanol is 20 times to 28 times the theoretical amount.   The production method according to claim 1, wherein the reaction step is performed at 50 to 80 ° C.   The production method according to any one of claims 1 to 4, further comprising a step of purifying the fatty acid methyl ester by distillation, washing with water, an adsorbent containing activated carbon, or an ion exchange resin.   The manufacturing method according to claim 1, wherein the fatty acid methyl ester is used as a biodiesel fuel.   A fatty acid methyl ester produced by the method according to claim 1.   A biodiesel fuel comprising the fatty acid methyl ester according to claim 7.