JP2002241786A - Method for producing fatty acid ester from seed and/or fruit of plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a fatty acid ester from a seed and/or a fruit by a simple method. SOLUTION: This method for producing a fatty acid ester comprises treating a seed and/or a fruit of a plant with a monohydric alcohol represented by the formula (1) R-OH...(1) (R is a 1-10C alkyl group) at >=180 deg.C under pressurization. The method for producing the fatty acid ester comprises treating the seed and/or the fruit of the plant with the monohydric alcohol under a condition to make the monohydric alcohol in a supercritical state. The monohydric alcohol is methanol in the production. The seed of the plant is one or more kinds of seeds of soybean, cole and kenaf in the production. The fruit of the plant is one or more kinds of fruits of olive and palm in the production.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a fatty acid ester which is an ester of a fatty acid and a monohydric alcohol (hereinafter sometimes simply referred to as "fatty acid ester") from plant seeds and / or fruits.

[0002]

2. Description of the Related Art Esters of fatty acids and monohydric alcohols are widely used as raw materials for surfactants. It has also been used as a diesel fuel instead of light oil.

[0003] Fatty acid esters are generally produced by reacting fats and oils (fatty acid triglycerides) extracted from plant seeds and fruits with monohydric alcohols. The method of obtaining oils and fats from plant seeds and fruits generally requires a complicated multi-stage oil extraction step including a pressing step, a solvent extraction step, a purification step, and the like. Using supercritical fluids in the oil extraction step, the supercritical CO ₂ in the temperature 40 ° C. and a pressure 400 kg / cm ^2, technology Hei 6-1 of extracting oil from perilla seeds
No. 36384 discloses this. However, what is obtained here is fats and oils, and in order to obtain a fatty acid ester, it was necessary to mix the fats and oils with a monohydric alcohol and further carry out a transesterification reaction.

[0004] A method of producing a fatty acid ester by reacting a fat and oil with a monohydric alcohol to carry out transesterification is already known. For example, JP-A-2000-1435
No. 86 discloses a method for producing a fatty acid ester by reacting fats and / or monohydric alcohols in a supercritical state without adding a catalyst when reacting fats and / or monohydric alcohols. It has been disclosed. However, a pre-process for extracting oils and fats from plant seeds and fruits was required.

[0005]

An object of the present invention is to provide a method for producing a fatty acid ester from a plant seed and / or fruit by a simple method.

[0006]

Means for Solving the Problems In view of the above situation, the present inventors have conducted intensive studies and as a result, have found that plant seeds and / or
Alternatively, the inventors have found that the above-mentioned problems can be solved by applying a monohydric alcohol to fruits under a pressurized condition at a certain temperature or higher, and have completed the present invention.

That is, the present invention relates to a method for producing plant seeds and / or
Alternatively, a monohydric alcohol represented by the general formula (1) R-OH (1) (wherein R represents an alkyl group having 1 to 10 carbon atoms) is added to the fruit at a temperature of 180 ° C or higher. Disclosed is a method for producing a fatty acid ester which operates under pressure conditions.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. In the present invention, an alcohol is allowed to act on the seeds and / or fruits of a plant under a pressurized condition of 180 ° C. or more to extract oils and fats from the seeds and / or fruits of the plant, and to extract the extracted oils and fats with monovalent. The present inventors have found that the production of a fatty acid ester by reaction with an alcohol proceeds in a one-step process, and have completed a fatty acid ester production process that is much simpler than in the prior art.

[0009] As a seed of a plant used as a raw material in the production method of the present invention, any seed can be used as long as it contains oils and fats. For example, soybean seeds, rapeseed seeds, kenaf seeds, sunflower seeds,
Grape seeds, rice seeds, cotton seeds, safflower seeds, castor seeds, sesame seeds, camellia seeds, mustard seeds, peanut seeds, corn seeds, flax seeds, palm seeds, apricot Seeds, perilla seeds, kiri seeds, Oyako seeds and the like. Preferred are soybean seeds, rapeseed seeds, and kenaf seeds. These seeds can be used alone or in a mixture. From the viewpoint of rapid growth, kenaf seeds are preferred.

[0010] As a fruit of a plant used as a raw material in the production method of the present invention, any fruit can be used as long as it contains an oil or fat. For example, olive fruits, palm fruits and the like can be mentioned. These fruits can be used alone or in a mixture.

By the way, fats and oils in plant seeds or fruits are those synthesized by plants from carbon dioxide in the air. Fatty acid esters produced from the fats and oils can be used as diesel fuel, and when used as fuel, carbon dioxide is generated. That is, it is attracting attention as a diesel fuel that can recycle carbon dioxide in the air and can suppress an increase in carbon dioxide in the global environment. The present inventors have also proposed a method of producing a diesel fuel suitable as a measure for suppressing carbon dioxide for preventing global warming by applying the production method of the present invention to plant seeds in a simpler process than before. You do it.

In the production method of the present invention, plant seeds and / or fruits can be used as they are, but they can be used even if the seeds and / or fruits are damaged or crushed. In the case of a fruit having a seed therein, the fruit can be used while containing the seed, or the seed can be removed and only the pulp can be used. In addition, seeds and / or fruits that have been subjected to pretreatment such as squeezing, pressing, peeling, cutting, heating, pressing, and drying can also be used.

In the production method of the present invention, R in the alcohol represented by the general formula (1), which is another starting material, is preferably an alkyl group having 1 to 10 carbon atoms. Is more preferable. The alkyl group may be linear, branched or cyclic. Specific examples of such alcohols include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, 2-butanol, t-butanol, n-pentanol, n-hexanol, cyclohexanol, n-heptanol, n-octanol, n
Examples thereof include -nonanol and n-decanol, and preferred are methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, 2-butanol and t-butanol. More preferred are methanol and ethanol, and still more preferred is methanol. These alcohols can be used alone or in a mixture.

The weight ratio of the alcohol represented by the general formula (1) to plant seeds and / or fruits is generally 0.01 to 100, preferably 0.03 to 50, and more preferably 0.05 to 20. Is more preferable,
More preferably, it is 0.1 to 5.

The fatty acid ester produced by the production method of the present invention is typically represented by caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid,
Esters such as, but not limited to, hexadecenoic acid, oleic acid, eicosenoic acid, erucic acid, linoleic acid, linolenic acid, ricinoleic acid. The alcohol residue of the fatty acid ester is determined by the monohydric alcohol used. For example, when methanol is used as a monohydric alcohol, a methyl ester is obtained, and when ethanol is used, an ethyl ester is obtained.

In the manufacturing method of the present invention, a temperature of 180
It is characterized by heating under a pressurized condition of not less than ° C. 18
When heating is performed at a temperature lower than 0 ° C., extraction of oil and fat components from seeds and / or fruits and transesterification of oil and fat may hardly proceed. The reaction is usually carried out under a pressure of at least atmospheric pressure. However, it is preferably carried out under a pressure of 2 MPa or more in order to accelerate the extraction of fats and oils and the transesterification of fats and oils. More preferred reaction conditions are conditions under which the monohydric alcohol represented by the general formula (1) is brought into a supercritical state.

Substances have inherent three states, gas, liquid, and solid. Further, when the temperature exceeds the critical temperature and the critical pressure, there is no distinction between gas and liquid, and the fluid does not condense (liquefy) even when pressure is applied. Become a phase. This state is called a supercritical state, and a substance in the supercritical state is called a supercritical fluid.

Supercritical fluids exhibit properties that are different from the normal properties of liquids and gases. The density of a supercritical fluid is close to that of the liquid of the substance, the viscosity of the supercritical fluid is close to that of the gas of the substance, and the thermal conductivity and diffusion coefficient are intermediate between gas and liquid.
A supercritical fluid is a "solvent that is not a liquid," and its extraction and reaction are likely to proceed at the same time due to its high density, low viscosity, and high diffusivity, but its mechanism is not clear. In addition, since the supercritical state has a density close to the liquid phase,
The size of the reactor can be reduced as compared with the gas phase reaction.

The conditions under which the monohydric alcohol is heated under the condition in which it becomes a supercritical state will be described below. When, for example, methanol is used as the monohydric alcohol, since the critical temperature of methanol is 239 ° C. and the critical pressure is 8.0 MPa, heating is performed at 239 ° C. or more and 8.0 MPa or more. When ethanol is used, since the critical temperature of ethanol is 241 ° C. and the critical pressure is 6.1 MPa, heating is performed at 241 ° C. or higher and 6.1 MPa or higher. When n-propanol is used, the critical temperature of n-propanol is 264 ° C., and the critical pressure is 5.2 MP.
a, the heating is performed under the conditions of 264 ° C. or more and 5.2 MPa or more. When n-butanol is used, n-butanol is used.
Butanol has a critical temperature of 290 ° C and a critical pressure of 4.4M.
Since it is Pa, heating is performed under the conditions of 290 ° C. or more and 4.4 MPa or more.

The heating temperature in the production method of the present invention is preferably 500 ° C. or less in order to suppress a side reaction. The temperature is more preferably 450 ° C or lower, and further preferably 400 ° C or lower. The pressure during heating is preferably 25 MPa or less. More preferably, it is 20 MPa or less. The heating time in the production method of the present invention is usually in the range of 1 minute to 24 hours.

In the production method of the present invention, the reaction proceeds efficiently without adding a catalyst, but it is also possible to add a catalyst to further increase the efficiency. The catalyst is not particularly limited as long as it increases the reaction efficiency, but a metal oxide or an alkali metal hydroxide, carbonate, hydrogencarbonate, or carboxylate is preferred because of its high reaction rate. More preferred are hydroxides and carbonates of alkali metals.

As the metal oxide, MgO, CaO, S
rO, BaO, ZnO, SiO_Two, GeO_Two, SnO_Two,
CuO, WO_Three, MnO_Two, MoO_ThreeAnd the like,
Preferably, they are MgO, CaO, SrO, and BaO. A
Examples of the hydroxide of the alkali metal include LiOH, NaOH,
KOH, RbOH and CsOH are mentioned. Alkali gold
As carbonates of the genus, Li_TwoCO_Three, Na_TwoCO_Three, K_TwoC
O_Three, Rb_TwoCO_Three, Cs _TwoCO_ThreeIs mentioned. alkali
As the metal bicarbonate, LiHCO_Three, NaHC
O_Three, KHCO_Three, RbHCO_Three, CsHCO_ThreeIs mentioned
You. Lithium acetate is an alkali metal carboxylate.
, Sodium acetate, potassium acetate, rubidium acetate,
Cesium acetate, sodium formate, potassium formate, propiate
Sodium onate, potassium propionate, sodium oxalate
Thorium, potassium oxalate and the like.

The amount of the catalyst to be used can be selected according to each reaction mode and scale, but it is generally used in an amount of 0.001% by weight or more and 10% by weight or less based on the seed amount. Preferably 0.0
1 wt% or more and 5 wt% or less, more preferably 0.1 wt% or less.
1% by weight or more and 2% by weight or less.

The production method of the present invention can be implemented in various modes. For example, it may be performed in a batch system or in a continuous flow system.

The product after heating in the production method of the present invention contains glycerin, unreacted monohydric alcohol, intermediates, other impurities and solid components in addition to fatty acid esters, plant seeds and / or fruits. May include. The desired fatty acid ester can be separated and purified to the purity required for various uses, but the method is not particularly limited, and depending on the properties of the fatty acid ester, general methods such as filtration, distillation, and extraction can be used. Methods can be applied.

According to the production method of the present invention, a fatty acid ester can be produced from a plant seed and / or fruit and a monohydric alcohol represented by the general formula (1) by a simple method.

[0027]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto. The mass of the product in the examples was determined from the peak area by size exclusion chromatography (SEC method). Confirmation of the production of fatty acid ester is performed by gas chromatography mass spectrometer HP-6890 (GC: Hewlett-
(Packard)-HP-5973 (MS: Hewlett-Packard).

EXAMPLE 1 208 mg of kenaf seeds and 1.50 g of methanol (Wako Pure Chemical Industries, special grade reagent) were autoclaved (stainless steel SU).
(S316, internal volume: 4.5 ml), and the temperature was raised to 250 ° C. in a sand bath, and the temperature was maintained for 30 minutes. Then, the autoclave was rapidly cooled, and after returning to room temperature, the reaction solution was taken out of the autoclave. When quantified by the above method, 39 mg of the intended methyl ester was obtained, and the amounts of triglyceride, diglyceride, and monoglyceride in the reaction solution were 3 mg, 5 mg, and 9 mg, respectively.

Since a pressure gauge is not attached to this autoclave, a pressure gauge is attached to the same autoclave, and the same amount of kenaf seed and 2.92 g of methanol (1.42 g corresponding to the dead volume of the pressure gauge are increased. The temperature was increased to 250 ° C in a sand bath,
The pressure was measured. The pressure value was 9 MPa, and the pressure during the reaction was also estimated to be 9 MPa. In this example, the reaction was performed under supercritical conditions.

Comparative Example 1 905 mg of kenaf seeds, 1.81 g of methanol, and 44 mg of sodium hydroxide (Wako Pure Chemical Industries, special grade of reagent) were charged into an eggplant flask, and the temperature was maintained for 1 hour in a water bath adjusted to 50 ° C. The reaction was performed. After cooling and returning to room temperature, the reaction solution was quantified by the above method, and as a result, less than 3 mg of the intended methyl ester was obtained. The amounts of triglyceride, diglyceride, and monoglyceride in the reaction solution are less than 3 mg, less than 3 mg, and 3 m, respectively.
g, and the extraction of oils and fats from kenaf seeds hardly occurred. This comparative example was a reaction under normal pressure liquid phase conditions.

Comparative Example 2 205 mg of kenaf seeds were ground in a mortar, and then autoclaved (SUS316) with 1.50 g of methanol.
, Internal volume of 4.5 ml), and 15 in a sand bath
The temperature was raised to 0 ° C. and maintained for 30 minutes. Then, the autoclave was rapidly cooled, and after returning to room temperature, the reaction solution was taken out of the autoclave. As a result of quantification by the above method, less than 3 mg of the intended methyl ester was obtained. Triglyceride, diglyceride,
The amount of monoglyceride is less than 40 mg and 3 mg respectively,
It was less than 3 mg.

Since a pressure gauge is not attached to this autoclave, a pressure gauge is attached to the same autoclave, and the same amount of kenaf seeds and 2.92 g of methanol (1.42 g corresponding to the dead volume of the pressure gauge is increased). The temperature was raised to 150 ° C in a sand bath,
The pressure was measured. The value of the pressure was 1 MPa, and the pressure during the reaction was also estimated to be 1 MPa. This comparative example was not a reaction under supercritical conditions.

Example 2 404 mg of soybean seeds and 1.50 g of methanol were charged into an autoclave (SUS316, internal volume: 4.5 ml), and the temperature was raised to 200 ° C. in a sand bath, and the temperature was maintained for 1 hour. Then, the autoclave was rapidly cooled, and after returning to room temperature, the reaction solution was taken out of the autoclave. When quantified by the above method, 36 mg of the intended methyl ester was obtained, and the amounts of triglyceride, diglyceride and monoglyceride in the reaction solution were 13 mg and 16 m, respectively.
g, 14 mg.

Since the autoclave is not provided with a pressure gauge, the same autoclave is provided with a pressure gauge, and the same amount of soybean seeds and 2.92 g of methanol (1.42 g corresponding to the dead volume of the pressure gauge is increased). Amount charged)
Was heated to 200 ° C. in a sand bath, and the pressure was measured. The value of the pressure was 4 MPa, and the pressure during the reaction was also estimated to be 4 MPa. This example was not a reaction under supercritical conditions.

Example 3 496 mg of soybean seeds and 1.50 g of methanol were charged in an autoclave (SUS316, internal volume: 4.5 ml), and the temperature was raised to 250 ° C. in a sand bath, and the temperature was maintained for 1 hour. Then, the autoclave was rapidly cooled, and after returning to room temperature, the reaction solution was taken out of the autoclave. When quantified by the above method, 100 mg of the intended methyl ester was obtained, and the amount of triglyceride, diglyceride, and monoglyceride in the reaction solution was less than 3 mg, respectively.
Less than 3 mg.

Since a pressure gauge is not attached to this autoclave, a pressure gauge is attached to the same autoclave, and the same amount of soybean seeds and 2.92 g of methanol (1.42 g corresponding to the dead volume of the pressure gauge is increased). Amount charged)
Was heated to 250 ° C. in a sand bath, and the pressure was measured. The pressure value was 9 MPa, and the pressure during the reaction was also estimated to be 9 MPa. In this example, the reaction was performed under supercritical conditions.

Comparative Example 3 373 mg of soybean seeds were ground in a mortar, and then charged in an autoclave (SUS316, internal volume: 4.5 ml) together with 1.50 g of hexane (Wako Pure Chemicals, special grade of reagent).
The temperature was raised to 150 ° C. in a sand bath and maintained for 3 hours. Then, the autoclave was rapidly cooled, and after returning to room temperature, the reaction solution was taken out of the autoclave. When quantified by the above method, the target methyl ester was 3 m
less than g. The amounts of triglyceride, diglyceride and monoglyceride in the reaction solution were 64
mg, less than 3 mg, less than 3 mg.

Since a pressure gauge is not attached to this autoclave, a pressure gauge is attached to the same autoclave, and the same amount of soybean seeds and 2.69 g of hexane (1.19 g corresponding to the dead volume of the pressure gauge is 1.19 g). Additional amount)
Was heated to 150 ° C. in a sand bath, and the pressure was measured. The pressure value was less than 0.5 MPa, and the pressure during the reaction was also estimated to be less than 0.5 MPa. This comparative example was not a reaction under critical conditions.

Example 4 502 mg of oilseed rape seeds and 1.50 g of methanol were charged into an autoclave (SUS316, internal volume: 4.5 ml), heated to 350 ° C. in a sand bath, and maintained at the temperature for 30 minutes. Then, the autoclave was rapidly cooled, and after returning to room temperature, the reaction solution was taken out of the autoclave. When quantified by the above method, 175 mg of the target methyl ester was obtained, and triglyceride,
The amounts of diglyceride and monoglyceride were less than 3 mg, less than 3 mg and less than 3 mg, respectively.

Since a pressure gauge was not attached to this autoclave, a pressure gauge was attached to the same autoclave, and the same amount of oilseed rape seeds and 2.92 g of methanol (1.42 g corresponding to the dead volume of the pressure gauge was increased). The temperature was raised to 350 ° C in a sand bath,
The pressure was measured. The pressure value was 20 MPa, and the pressure during the reaction was also estimated to be 20 MPa. In this example, the reaction was performed under supercritical conditions.

COMPARATIVE EXAMPLE 4 501 mg of oilseed rape was ground in a mortar and then autoclaved (SUS316) with 1.50 g of hexane.
, Internal volume of 4.5 ml), and 15 in a sand bath
The temperature was raised to 0 ° C. and maintained for 3 hours. Then, the autoclave was rapidly cooled, and after returning to room temperature, the reaction solution was taken out of the autoclave. As a result of quantification by the above method, less than 3 mg of the intended methyl ester was obtained. Triglyceride, diglyceride,
The amount of monoglyceride was 173 mg, less than 3 mg and less than 3 mg, respectively.

Since a pressure gauge is not attached to this autoclave, a pressure gauge is attached to the same autoclave, and the same amount of oilseed rape seeds and 2.69 g of hexane (add 1.19 g corresponding to the dead volume of the pressure gauge). The temperature was raised to 150 ° C in a sand bath,
The pressure was measured. The value of the pressure is less than 0.5 MPa;
The pressure during the reaction was also estimated to be less than 0.5 MPa. This comparative example was not a reaction under supercritical conditions.

Example 5 610 mg of rapeseed seeds and 1.76 g of methanol were charged into an autoclave (SUS316, internal volume: 4.5 ml), and the temperature was raised to 250 ° C. in a sand bath, and the temperature was maintained for 30 minutes. Then, the autoclave was rapidly cooled, and after returning to room temperature, the reaction solution was taken out of the autoclave. When quantified by the above method, the desired methyl ester was obtained in an amount of 77 mg, and the amounts of triglyceride, diglyceride, and monoglyceride in the reaction solution were each 104 m.
g, 70 mg, and 26 mg.

Since a pressure gauge is not attached to this autoclave, a pressure gauge is attached to the same autoclave, and the same amount of oilseed rape seeds and 3.18 g of methanol (1.42 g corresponding to the dead volume of the pressure gauge are increased). The temperature was increased to 250 ° C in a sand bath,
The pressure was measured. The pressure value was 9 MPa, and the pressure during the reaction was also estimated to be 9 MPa. In this example, the reaction was performed under supercritical conditions.

Example 6 614 mg of oilseed rape, 1.77 g of methanol, and 5 mg of lithium hydroxide monohydrate (Wako Pure Chemical Industries, special grade of reagent) were autoclaved (SUS316, internal volume 4.5 ml).
And the temperature was raised to 250 ° C. in a sand bath, and the temperature was maintained for 30 minutes. Then, the autoclave was rapidly cooled, and after returning to room temperature, the reaction solution was taken out of the autoclave.
When quantified by the above method, 218 mg of the intended methyl ester was obtained, and the amount of triglyceride, diglyceride, and monoglyceride in the reaction solution was 3 m each.
Less than 5 g, 12 mg. The estimated pressure during the reaction was 9 MPa, and the present example was a reaction under supercritical conditions.

Example 7 609 mg of oilseed rape seeds, 1.76 g of methanol, and 1 mg of sodium hydroxide (Wako Pure Chemicals, special grade reagent) were charged into an autoclave (SUS316, internal volume: 4.5 ml), and heated to 250 ° C. in a sand bath. The temperature was raised and maintained for 30 minutes. Then, the autoclave was rapidly cooled, and after returning to room temperature, the reaction solution was taken out of the autoclave. As a result of quantification by the above method, 117 mg of the intended methyl ester was obtained, and the amount of triglyceride, diglyceride, and monoglyceride in the reaction solution was 40 mg and 3 mg, respectively.
6 mg and 27 mg. Estimated pressure during reaction is 9M
At Pa, this example was a reaction under supercritical conditions.

Example 8 611 mg of oilseed rape, 1.76 g of methanol, and 6 mg of anhydrous sodium carbonate (Wako Pure Chemical Industries, special grade of reagent) were charged into an autoclave (SUS316, internal volume: 4.5 ml), and heated to 250 ° C. in a sand bath. The temperature was raised and maintained for 30 minutes. Then, the autoclave was rapidly cooled, and after returning to room temperature, the reaction solution was taken out of the autoclave. When quantified by the above method, 155 mg of the intended methyl ester was obtained, and the amounts of triglyceride, diglyceride, and monoglyceride in the reaction solution were each 15 mg,
They were 21 mg and 30 mg. The estimated pressure during the reaction was 9
MPa, and this Example was a reaction under supercritical conditions.

Example 9 517 mg of olive pulp and 1.50 g of methanol (Wako Pure Chemical Industries, special grade reagent) were autoclaved (SUS316).
, Internal volume of 4.5 ml) and put in a sand bath for 25
The temperature was raised to 0 ° C. and maintained for 1 hour. Then, the autoclave was rapidly cooled, and after returning to room temperature, the reaction solution was taken out of the autoclave. When quantified by the above method, 66 mg of the target methyl ester was obtained, and the amounts of triglyceride, diglyceride, and monoglyceride in the reaction solution were 0 mg, 0 mg, and 0 mg, respectively.

Since a pressure gauge is not attached to this autoclave, a pressure gauge is attached to the same autoclave, and the same amount of olive pulp and 2.92 g of methanol (additional amount of 1.42 g of dead volume equivalent to the pressure gauge is added. ), The temperature was raised to 250 ° C. in a sand bath, and the pressure was measured. The pressure value was 9 MPa, and the pressure during the reaction was 9 M
Pa was estimated. In this example, the reaction was performed under supercritical conditions.

Example 10 Olive pulp (520 mg) and methanol (1.50 g) were autoclaved (SUS316, internal volume: 4.5 ml).
And the temperature was raised to 300 ° C. in a sand bath, and the temperature was maintained for 30 minutes. Then, the autoclave was rapidly cooled, and after returning to room temperature, the reaction solution was taken out of the autoclave.
When quantified by the above method, 68 mg of the target methyl ester was obtained, and triglyceride in the reaction solution,
The amounts of diglyceride and monoglyceride are each 0 mg,
0 mg and less than 3 mg. The estimated pressure during the reaction is 1
4 MPa, and this example was a reaction under supercritical conditions.

Comparative Example 5 Olive pulp (527 mg) and methanol (1.50 g) were autoclaved (SUS316, internal volume: 4.5 ml).
And the temperature was raised to 150 ° C. in a sand bath, and the temperature was maintained for 30 minutes. Then, the autoclave was rapidly cooled, and after returning to room temperature, the reaction solution was taken out of the autoclave.
As a result of quantification by the above method, less than 3 mg of the intended methyl ester was obtained. The amounts of triglyceride, diglyceride and monoglyceride in the reaction solution were 25 mg, 0 mg and 0 mg, respectively.

Since a pressure gauge was not attached to this autoclave, a pressure gauge was attached to the same autoclave, and the same amount of olive pulp and 2.92 g of methanol (1.42 g corresponding to the dead volume of the pressure gauge was increased). The temperature was raised to 150 ° C in a sand bath,
The pressure was measured. The value of the pressure was 1 MPa, and the pressure during the reaction was also estimated to be 1 MPa. This comparative example was not under supercritical conditions.

Comparative Example 6 512 mg of olive pulp was pulverized in a mortar, and then charged in an autoclave (SUS316, internal volume: 4.5 ml) together with 1.50 g of hexane (Wako Pure Chemicals, special grade of reagent), and 150 ° C. in a sand bath. And the temperature was maintained for 3 hours. Then, the autoclave was rapidly cooled, and after returning to room temperature, the reaction solution was taken out of the autoclave. As a result of quantification by the above method, less than 3 mg of the intended methyl ester was obtained. The amount of triglyceride, diglyceride and monoglyceride in the reaction solution was 6
It was less than 8 mg, 0 mg and 3 mg. The estimated pressure during the reaction was 0.5 MPa, and this comparative example was a reaction under conditions other than supercritical conditions.

[0054]

According to the method of the present invention, a fatty acid ester can be produced from a plant seed and / or fruit and a monohydric alcohol by a simple method, so that the present invention is industrially useful. .

Claims (7)

[Claims] A monovalent compound represented by the general formula (1) R-OH (1) (wherein R represents an alkyl group having 1 to 10 carbon atoms) on a seed and / or a fruit of a plant. A method for producing a fatty acid ester, wherein an alcohol is allowed to act under a pressurized condition at a temperature of 180 ° C. or higher. 2. The method according to claim 1, wherein the pressure condition is a pressure of 2 MPa or more. 3. The method according to claim 1, wherein the monohydric alcohol is allowed to act under supercritical conditions. 4. The method according to claim 1, wherein the monohydric alcohol is methanol. 5. The method according to claim 1, wherein the plant seed is one or more seeds of soybean, rape and kenaf. 6. The method according to claim 1, wherein the fruit of the plant is one or more fruits of olives and palms. 7. The method according to claim 1, wherein an alkali metal hydroxide or an alkali metal carbonate is used as the catalyst.