JP2001226694A - Method of producing fatty acid ester and fuel containing fatty acid ester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of efficiently producing fatty acid esters and glycerol in high yields from oils and fats and an alcohol under more suitable conditions, and to provide a fuel containing the fatty acid esters. SOLUTION: This method for producing the fatty acid esters and the glycerol from oils and fats and an alcohol, characterized by reacting the oils and fats with the alcohol under a condition that the oils and fats and/or the alcohol are converted into a supercritical state, and the fuel, diesel fuel, lubricant base oil or fuel oil additive, characterized by containing the fatty acid ester produced by the production method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing fatty acid esters and glycerin by reacting fats and oils and alcohols, and a fuel containing the fatty acid esters obtained by the production method.

[0002]

BACKGROUND OF THE INVENTION Fats and oils are mainly composed of esters of fatty acids and glycerin called triglycerides, and fatty acid esters obtained by transesterification using fats and oils and alcohols are widely used in industrial raw materials and pharmaceuticals.

[0003] Ester exchange by reacting fats and oils with alcohol
By replacing the mineral oil, fatty acid es
Method for producing diesel fuel and lubricating base oil containing tel
Have been reported. For example, JP-A-9-235573
In the official gazette and Japanese Patent Application Laid-Open No.
Reaction between waste cooking oil and methanol in the presence of
Manufactures diesel fuel. JP-A-07-97047
In the gazette, the transesterification reaction usually involves caustic soda
50 ° C to 70 ° C under atmospheric pressure using an alkaline catalyst of
It is described to be performed at a temperature. In this case,
If free fatty acids are present in the stone,
Pretreatment is indispensable because of the formation of soap.
A small amount of soap is formed during the transesterification reaction
Therefore, it is necessary to separate in post-processing. Meanwhile, this ester
The exchange reaction is performed under the conditions of 9 to 10 MPa and 220 to 250 ° C.
In this case, low-purity oils and fats containing free fatty acids are used.
It is also known that they can be
Cyclopedia of Industrial Chemis
Tree 5 Completely Revised Edition (Ullmann's Enc
Cyclopediaof Industrial Ch
emistry Fifth Completely
Revised Edition)], Volume A10 (1
987), p. 281).

Further, US Pat. No. 5,713,965 is disclosed.
Oil and fat in hexane solvent in the presence of lipase.
Diesel fuel containing fatty acid esters from coal and
A method for producing a lubricating oil is disclosed. Catalyst under pressure
Of fatty acid esters from oils and fats and alcohols
Is also known [Ulman Enzyklopede
I Der Technischen Hemy (Ullmann
 Enzyklopadie der Technis
chen Chemie), 4th edition, 11th volume (197
6 years), p. 432). That is, 10 MPa, 240
C., under conditions of 7 to 8 times excess methanol, alkaline catalyst
Alternatively, the reaction is performed using a zinc catalyst. Oils and fats
And alcohol at 240 ° C. and 9 MPa in the presence of an alkali catalyst.
(90 bar) to produce fatty acid ester
Technology [Journal of the American Oil
Chemist's Society (Journal of the
e American Oil Chemists ‘
Society), vol. 61, no. 2 (1984)]
However, details of the alkali catalyst are not clear.
No. In addition, sodium carbonate or carbonate
At normal pressure or near normal pressure using sodium hydrogen
Reaction at the boiling point of the alcohol used or at a temperature close to it
A method has been proposed (Japanese Patent Application Laid-Open No. 61-25425).
No. 5), but the reaction is slow and the productivity is insufficient.
You. Fats and alcohols with ZnO or Zn and Al
Under the composite oxide catalyst, in the range of 170 to 250 ° C, 10MP
a (100 bar) or less to produce fatty acid esters
Technology (US Pat. No. 5,908,946)
But the response is slow as well. In addition, Arca
25 to 25 using a solid catalyst containing an earth metal oxide
260 ° C., 0.1 MPa (1 atm) to 10.1
Under the pressure of MPa (100 atm), fats and oils and alcohol
Method for selectively producing monoglyceride by reacting
(Pain Patent No. 2124166).
Produce fatty acid alkyl esters and glycerin
No method is disclosed.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a fatty acid ester and glycerin efficiently and in a high yield from fats and oils and an alcohol under more appropriate conditions, and a fuel containing the fatty acid ester. Is to do.

[0006]

Means for Solving the Problems The present inventors have continued intensive studies on a method for producing fatty acid esters and glycerin by reacting fats and oils with alcohols and a fuel containing fatty acid esters, and added a solid catalyst containing a nickel compound. Then, it was found that if the reaction was carried out under the condition that the fats and / or alcohols were in a supercritical state, the reaction would proceed in high yield, and the present invention was completed. That is, the present invention provides the following inventions [1] to [5]. [1] A method for producing a fatty acid ester and glycerin from an oil and a fat, wherein a fatty acid ester and a glycerin are reacted by adding a nickel-containing solid catalyst under conditions where the oil and the fat and / or the alcohol become supercritical. Manufacturing method. [2] A fuel containing the fatty acid ester and glycerin produced by the production method according to the above [1]. [3] A diesel fuel containing the fatty acid ester and glycerin produced by the production method according to [1]. [4] A lubricating base oil containing a fatty acid ester and glycerin produced by the production method according to [1]. [5] A fuel oil additive containing the fatty acid ester and glycerin produced by the production method according to [1].

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The main reaction of the production method of the present invention is represented by the following reaction formula (2)
Indicated by

[0008]

Embedded image

(Wherein R ₁ , R ₂ and R ₃ are each independently
Shows the carbon chain of the fatty acid. The carbon number of R _{1 to} R ₃ varies depending on the type of fat. R ₄ represents a hydrocarbyl group which may be substituted with a hydrocarboxyl group.) The fat or oil used in the present invention is mainly composed of triglyceride which is an ester of fatty acid and glycerin. Here, “mainly containing triglyceride” means that triglyceride is 5% of fats and oils.
0% by weight or more is meant.

The fats and oils used in the present invention are represented by the reaction formula (2)
It is a substance mainly containing triglyceride 1 of the fatty acid shown, and it is possible to use natural fats and oils
But good. For fats and oils, as typical examples, lard fat,
Chicken fat, butterfat, beef tallow, cocoa butterfat, corn
Sorghum oil, peanut oil, cottonseed oil, soybean oil, coconut oil,
Olive oil, safflower oil, linseed oil, coconut oil,
Oak oil, almond oil, apricot kernel oil, beef bone fat, clog
Lumi oil, castor oil, large apricot oil, cinnamon fat, cod liver oil, cottonseed
Stearin, sesame oil, tallow, dolphin butter, sardine oil, mackerel
Oil, horse fat, lard, bone oil, linseed oil, sheep fat, beef leg oil, par
Oil, palm kernel oil, porpoise oil, shark oil, sperm
There are whale oil, tung oil, whale oil, etc.
Not limited. Also, a mixture of a plurality of these fats and oils
Of fats and oils, including diglycerides and monoglycerides, some,
Fats and oils that have undergone modification such as oxidation and reduction may be used. Also, not yet
Refined fats and oils containing free fatty acids and water
Good, or abolished from restaurants, food factories, ordinary households, etc.
Waste cooking oil may be discarded, but appropriate pretreatment if necessary
Is preferably performed. For example, the present invention is applied to waste cooking oil and the like.
Insoluble solids are mixed into fats and oils when applied to waste oil
Of the pump and the pressure control valve,
Wire mesh before feeding to the preheater,
Removing insoluble solids from fats and oils with a filter, etc.
Is preferred.

The fats and oils may contain components other than fats and oils. Specifically, crude oil, heavy oil, light oil, mineral oil, essential oil, coal, fatty acid, saccharide, metal powder, metal salt, protein, amino acid, hydrocarbon, cholesterol, flavor, coloring compound, enzyme, fragrance, alcohol, fiber, Resin, rubber,
Paints, cements, detergents, aromatics, aliphatics,
Examples include, but are not limited to, soot, glass, earth and sand, nitrogen-containing compounds, sulfur-containing compounds, phosphorus-containing compounds, and halogen-containing compounds.

The above substances contained in fats and oils may be involved in the reaction, for example, when they may inhibit the reaction, or when they are solid and may be clogged in the production process. Is preferably removed using a technique such as filtration or distillation before the reaction. As a method of distillation,
Examples thereof include, but are not limited to, vacuum distillation, steam distillation, molecular distillation, and extractive distillation. In the present invention, waste fats and oils, waste edible oils, and the like can be used as the fats and oils.

The alcohol (2 in the reaction formula (2)) used in the present invention is not particularly limited.

An alcohol represented by the formula: R-OH (1) wherein R represents a hydrocarbyl group having 1 to 10 carbon atoms or a hydrocarbyl group having 2 to 10 carbon atoms and substituted by a hydrocarbyloxyl group. preferable.

Examples of the hydrocarbyl group having 1 to 10 carbon atoms in R include, for example, an alkyl group, an aralkyl group, an alkenyl group and an alkynyl group.

Examples of the alcohol in which R is an alkyl group include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol and t-
Butanol, pentanol, hexanol, cyclohexanol, heptanol and the like are exemplified.

Examples of the alcohol in which R is an aralkyl group include benzyl alcohol, α-phenethyl alcohol, β
-Phenethyl alcohol, with benzyl alcohol being preferred.

Examples of the alcohol wherein R is an alkenyl group include allyl alcohol, 1-methylallyl alcohol,
2-methylallyl alcohol, 3-butene-1-o-
And allyl alcohol is preferred.

Examples of the alcohol in which R is an alkynyl group include 2-propyn-1-ol, 2-butyn-1-o-
And 3-butyn-1-ol, 3-butyn-2-ol and the like.

Examples of the alcohol in which R is a hydrocarbyl group substituted with a hydrocarboxyl group having 2 to 10 carbon atoms include 2-methoxyethanol, 2-methoxypropanol and 3-methoxybutanol.

Among them, as the alcohol, R is preferably an alkyl group having 1 to 4 carbon atoms. Specifically, methanol in which R is a methyl group, ethanol in which R is an ethyl group, propanol in which R is a propyl group,
Isopropanol wherein R is an isopropyl group, R is n-
Preferred are n-butanol which is a butyl group, isobutanol where R is an isobutyl group, and t-butanol where R is a t-butyl group, more preferably methanol and ethanol, and even more preferably methanol. The purity of the alcohol is not particularly limited, but is preferably 9
It is at least 5%, more preferably at least 98%. One type of alcohol may be used, or two or more types may be mixed and used. In addition, the alcohol also includes an optical isomer when an optical isomer is present.

The supply weight of alcohol is preferably 1 to 100 times the theoretical supply weight of alcohol calculated according to the following equation.

[0022]

## EQU1 ## Theoretical supply weight of alcohol = (supply weight of fat / oil × saponification value of fat / oil × molecular weight of alcohol) ÷ 56100

(Here, the saponification value of fats and oils means 1 g of fats and oils.
(The amount of potassium hydroxide required to completely saponify is expressed in mg.) When the ratio is smaller than 1, the reaction yield decreases, which is not preferable. If it is larger than 100, the apparatus may be too large, which is not preferable.

Representative examples of the fatty acid ester 3 produced by the reaction of the formula (2) include valeric acid, caproic acid, enantonic acid, caprylic acid, pelargonic acid, capric acid, undecylic acid, lauric acid and tridecyl. Acid, myristic acid, pentadecylic acid, palmitic acid, heptedesylic acid, stearic acid, nonadecanoic acid, arachiic acid, penic acid, lignoceric acid, serotinic acid, heptacosanoic acid, montanic acid, melisic acid, lacceric acid, crotonic acid, isocrotonic acid , Undecylenic acid, oleic acid, elaidic acid, setleic acid, erucic acid, brassic acid, sorbic acid, linoleic acid, linolenic acid, arachidonic acid, propiolic acid, stearolic acid, nervonic acid, ricinoleic acid,
Examples include, but are not limited to, esters such as (+)-hydronocarbic acid and (+)-chaurum-grulinic acid. The alcohol residue of the ester is determined by the alcohol used. For example, when methyl alcohol is used as the alcohol, a methyl ester is obtained, and when ethyl alcohol is used, an ethyl ester is obtained. When the fatty acid residue has an optical isomer, the fatty acid residue also includes the optical isomer. Further, in the present manufacturing method,
In addition to fatty acid esters, the main product is glycerin 4
Is generated.

Next, the catalyst used in the present invention will be described.
You. The catalyst used in the present invention contains a nickel compound
It is a solid catalyst. For example, nickel oxide (NiO, N
i_TwoO_Three, NiO and Ni_TwoO_ThreeComposite oxide), nickel carbonate
Metal, nickel hydroxide, basic nickel carbonate, etc.
Solid catalysts and carriers such as silica and zeolite.
Solid catalysts impregnated with a nickel compound
You. Preferably, a solid catalyst containing nickel oxide
is there. The amount of the catalyst used is based on 100 parts by weight of fats and oils.
From 0.01 to 6 parts by weight, more preferably from 0.1 to 6 parts by weight.
1 to 3 parts by weight is more preferred.

The supercritical state in the present invention means the following state. Substances have three distinct states: gas, liquid, and solid.
Furthermore, above the critical temperature, there is a fluid phase that does not condense even when pressure is applied. This state is called a supercritical state. Fluids in the supercritical state exhibit properties that are different from the normal properties of liquids and gases. A supercritical fluid has a density close to that of a liquid, a viscosity close to that of a gas, and a thermal conductivity and diffusion coefficient that are intermediate properties between a gas and a liquid.
Mass transfer is advantageous due to high diffusivity, and high heat transfer can be obtained due to high heat transfer. Because of such a special state, in the supercritical state, the reactivity becomes higher than in a normal gas-liquid state, and the transesterification reaction is further promoted.

The "conditions under which the fats and / or alcohols become supercritical" include the following conditions (a) to (c). (A) Temperature conditions under which the mixture of fats and oils and alcohol becomes a supercritical state. (B) Temperature conditions under which the alcohol becomes a supercritical state. (C) Temperature conditions under which the fat or oil becomes a supercritical state. It is preferable to carry out the reaction under the conditions (a) or (b).

As the condition (b), specifically, when methanol is used as the alcohol, the reaction is carried out at a temperature of 240 ° C. or higher because the critical temperature of methanol is 240 ° C. When ethanol is used, the reaction is performed at a temperature of 243 ° C. or higher because the critical temperature of ethanol is 243 ° C. For propanol, the critical temperature is 264
The reaction is performed at a temperature of 264 ° C. or higher. When butanol is used, the critical temperature is 287 ° C.
The reaction is carried out at a temperature of at least 87 ° C. When isopropanol is used, the reaction is performed at a temperature of 236 ° C. or higher because the critical temperature is 236 ° C. When isobutanol is used, the reaction is performed at a temperature of 275 ° C. or higher because the critical temperature is 275 ° C. If t-butanol is used, the critical temperature is 2
The reaction is performed at a temperature of 233 ° C. or higher because the temperature is 33 ° C. Although the upper limit of the reaction temperature is not limited, a decomposition reaction or the like may occur, and is preferably 400 ° C. or lower.

The alcohol density conditions in the reaction vessel for reacting the fat and oil of the present invention with alcohol are not limited.
The pressure is preferably in the range of 0.01 g / cm ³ to 0.4 g / cm ³ , and the pressure condition is preferably in the range of 0.5 MPa to 25 MPa.

[0030] In addition, the fats and oils of the present invention react with alcohol
The duration is preferably in the range of 0.1 to 180 minutes.
More preferably, the range is 0.5 to 120 minutes.
More preferably, the range is from 1 minute to 60 minutes.

This reaction can be carried out in various reaction modes. For example, it may be performed by a batch method or a distribution method. In the present invention, the fats and oils and the alcohol may be uniformly mixed during the reaction, or may be separated into two layers as long as they can react. In the case of separation into two layers, for example, the reaction can be further efficiently performed by increasing the contact area between the two layers by performing the reaction under stirring.

After completion of the reaction, the reaction mixture contains fatty acid esters, glycerin, excess unreacted alcohol, and may further contain unreacted raw materials and other impurities. From this reaction mixture to the purity required for each application,
Purify the fatty acid ester. The method for purification is not particularly limited, and general methods such as distillation and extraction can be applied according to the properties of the fatty acid ester to be produced. For example, in the case where methanol is used as the alcohol, an excess (or unreacted) methanol component is vaporized, separated and collected, and then allowed to stand still to be separated into a light liquid and a heavy liquid. The catalyst used in the present invention is relatively easy to separate from the reaction solution as compared with caustic soda catalyst and the like, and post-treatment of the reaction solution is simple. The light liquid is mainly composed of a fatty acid methyl ester and can be used as a raw material for diesel fuel or a raw material for natural higher alcohols. Further, the heavy liquid of glycerin main component can be used as a raw material of industrial glycerin. Separation of unreacted alcohol, other than distillation such as vacuum distillation, may be exemplified by mixer-settler extraction, liquid-liquid extraction, extraction using a pulse column, jet extraction, Bodovierniak rotary extraction, etc. But,
It is not limited to this. Further, the alcohol may be completely separated, and only the fatty acid ester may be taken out, or the alcohol may be recovered in a state where the alcohol remains.

The fatty acid ester produced by the method of the present invention depends on the structure of the raw material fat, but when a natural fat or oil is used, it is generally a mixture of several fatty acid esters. In this case, the mixture can be used as it is depending on the application, or if necessary, only a specific fatty acid ester can be separated and used by a general method such as distillation or extraction.

The fatty acid ester produced as described above may be used alone or in a fuel such as a diesel fuel, a lubricating base oil, a fuel oil additive or the like, depending on the use requirements.
It can be used by mixing with other components.

[0035] New Automobile Engineering Handbook (Corporation
According to the Society of Automotive Engineers of Japan), when used as diesel fuel, ignitability and viscosity are important. If a fatty acid ester having a relatively low viscosity is used, it causes abrasion or burning, so that it is necessary to use a fatty acid ester having a viscosity suitable for a diesel engine. On the other hand, if the molecular weight is too high, it causes odor and smoke emission, so such fatty acid esters are not preferred. For example, fatty acid methyl ester, fatty acid ethyl ester, fatty acid isopropyl ester, fatty acid isobutyl ester and the like are preferably used as diesel fuel. Among them, fatty acid isopropyl ester,
Fatty acid isobutyl ester becomes a diesel fuel with high properties at low temperatures. Even when used as a lubricating base oil, viscosity is important. For summer use, a relatively high viscosity is desired in order to provide high lubricity, but when used in winter or at a low temperature, a relatively low viscosity, high fluidity fatty acid ester is desired. Therefore, a wide range of fatty acid esters can be used as the lubricating base oil. As a fuel oil additive, a fatty acid ester is added to fuel mainly for the purpose of reducing friction. It plays almost the same role as the lubricating oil, and the same properties as the lubricating base oil are desired.

[0036] The produced fatty acid ester is
As long as there is no problem in use, glycerin, excess unreacted alcohol, unreacted fats and oils, and other impurities contained in the reaction mixture after the reaction may be contained within the range. Further, if necessary for the application, the yield can be further improved by repeating the reaction under the conditions of the present invention.

[0037]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Embodiment 1  Soybean oil 0.86 as a fat mainly composed of triglycerides
1 g, methanol 1.242 g as alcohol, catalyst
Nickel oxide (NiO and Ni_TwoO_ThreeComplex oxidation of
Product) 10.9 mg of powder was weighed and placed in a stainless steel reaction tube.
(About 4.5cm^Three) And sealed. This reaction tube,
Put into a fluidized bed sand bath temperature-controlled to 300 ° C
After heating and reacting, take it out after 10 minutes and immediately
Charged and cooled. Amount of methanol used for this reaction
Is the process required to completely methylate soybean oil.
It was about 13 times the stoichiometric amount. A thermocouple is installed on the reaction tube wall.
The temperature was measured at approximately 260 ° C after 2 minutes.
It was above the critical temperature of tanol. Also, from the reaction volume
The calculated initial methanol density is about 0.28 g / c.
m^ThreeMet. Next, after the primary recovery of the reaction solution in the reaction tube,
Methanol washing was repeated three times and recovered.
The catalyst thus obtained had settled out in the recovered liquid. In this recovered liquid
Chromatographic separation of the methyl ester and glycerin components of
When the reactivity was evaluated by quantitative analysis by chromatography,
The methyl ester yield is about 98%, and the glycerin yield is about 9
1%. Here, the yield refers to 1 mol of soybean oil.
3 mol of methyl ester and 1 mol of glycerin
It is a value calculated based on the reaction.

Example 2 A test was conducted in the same manner as in Example 1 except that 0.867 g of soybean oil, 1.241 g of methanol, and 29.1 mg of nickel oxide powder were used. As a result of analysis of the recovered solution, the yield of methyl ester was about 98%, and the yield of glycerin was about 91%.

Comparative Example 1 Example 1 was repeated except that 0.858 g of soybean oil, 1.239 g of methanol, and 10.2 mg of zinc oxide (ZnO) powder were used.
The test was performed in the same manner as described above. As a result of analyzing the recovered solution, the yield of methyl ester was about 58%, and the yield of glycerin was about 30%.
%Met.

[0041]

According to the present invention, it is possible to provide a method for producing a fatty acid ester from fats and oils and alcohols in a simple and high yield, and a fuel containing the fatty acid ester and the like. Is big. It is also useful from the viewpoint of resource reuse and pollution prevention.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) C07C 69/58 C10L 1/02 C10L 1/02 1/08 1/08 1/18 Z 1/18 C10M 105 / 34 C10M 105/34 C11B 13/00 C11B 13/00 C10N 40:25 // C10N 40:25 B01J 23/74 321X F-term (reference) 4H006 AA02 AA03 AB44 AC13 AC41 AC48 BA21 BA29 BA30 BA32 4H013 BA00 BA02 CE03 4H039 CA60 CA66 CD10 CD40 4H059 BA12 BA13 BA30 BC03 BC13 CA36 CA72 CA73 CA94 EA17 4H104 BB32A JA01

Claims (13)

[Claims] 1. A method for producing a fatty acid ester from fats and oils and alcohols, wherein a fatty acid ester and glycerin are reacted by adding a nickel-containing solid catalyst under conditions in which the fats and oils and / or alcohol become supercritical. Manufacturing method. 2. The method for producing fatty acid esters and glycerin according to claim 1, wherein the nickel-containing solid catalyst is a catalyst containing nickel oxide. 3. The method for producing fatty acid ester and glycerin according to claim 1, wherein the reaction is carried out under a condition in which the alcohol is brought into a supercritical state. 4. The method for producing a fatty acid ester and glycerin according to claim 3, wherein the alcohol is represented by the following general formula (1). ## STR1 ## R-OH (1) (R is a group having 1 to 1 carbon atoms.)
0 represents a hydrocarbyl group or a hydrocarbyl group having 2 to 10 carbon atoms and substituted with a hydrocarboxyl group. ) 5. The method for producing a fatty acid ester and glycerin according to claim 4, wherein R in the general formula (1) is an alkyl group having 1 to 4 carbon atoms. 6. The method according to claim 5, wherein R in the general formula (1) is a methyl group or an ethyl group. 7. The method for producing a fatty acid ester and glycerin according to claim 6, wherein R in the general formula (1) is a methyl group. 8. The method for producing a fatty acid ester and glycerin according to claim 1, wherein the fat or oil is a waste fat or oil. 9. The method for producing a fatty acid ester and glycerin according to claim 1, wherein the fat or oil is a waste cooking oil. 10. A fuel containing a fatty acid ester produced by the production method according to claim 1. 11. A diesel fuel containing a fatty acid ester produced by the production method according to claim 1. 12. A lubricating base oil containing a fatty acid ester produced by the production method according to any one of claims 1 to 9. 13. A fuel oil additive containing a fatty acid ester produced by the production method according to any one of claims 1 to 9.