JP2004263011A - Method for producing fatty acid ester and production apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing fatty acid esters, by which the fatty acid esters capable of being used as an alternate fuel can efficiently be produced from a fat or fatty oil raw material containing fats or fatty oils as a main component, and to provide an apparatus for producing the same. <P>SOLUTION: This method for producing the fatty acid esters is characterized by comprising a process of hydrolyzing the fat or fatty oil raw material containing the fats or fatty oils as a main component to produce the free fatty acids, and a process of esterifying the obtained fatty acid raw material containing the free fatty acids as the main component in a condition comprising the supercritical state of the alcohol to produce the fatty acid esters. The apparatus for producing the fatty acid esters is characterized by comprising a hydrolysis means A1 for hydrolyzing the fat or fatty oil raw material to produce the free fatty acids, and a tubular reactor 4 for dissolving the alcohol and the fat or fatty oil raw material containing the free fatty acids in each other and simultaneously making the mixture solution to pass through the reactor to continuously perform the esterification reaction. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and an apparatus for producing a fatty acid ester, and more particularly, to a method and an apparatus for producing a fatty acid ester for producing a fatty acid ester from a fat or oil raw material containing fats and oils as a main component.
[0002]
[Prior art]
In recent years, for example, a method of regenerating vegetable edible waste oil such as tempura oil as a light oil alternative fuel has been developed, and there are many apparatuses for that purpose.
By the way, the conventional method of regenerating waste oil into light oil alternative fuel is a so-called chemical method using an alkali catalyst (NaOH, KOH). According to this method, fats and oils present in the form of triglycerides in waste oil are removed. It can be converted to fuel (for example, see Patent Document 1, Patent Document 2, and Patent Document 3).
In addition, there is a method of producing an alkyl ester of a fatty acid by reacting a raw material of fat and oil with an alcohol in an atmosphere in which the alcohol is in a supercritical state, thereby subjecting a triglyceride contained in the fat and oil to a transesterification reaction (for example, Patent Reference 4).
[0003]
[Patent Document 1]
JP-A-7-197047
[Patent Document 2]
JP-A-7-310090
[Patent Document 3]
JP-A-9-235573
[Patent Document 4]
JP 2001-31991 A
[0004]
[Problems to be solved by the invention]
However, in the methods of Patent Documents 1, 2, and 3, the fatty acid contained in the fat or oil raw material becomes fatty acid soap, and therefore cannot be regenerated as a light oil alternative fuel, and the yield is reduced. Therefore, when a fat or oil as a raw material contains a large amount of free fatty acid, a pretreatment for removing the free fatty acid is required in advance. Further, when an alkali catalyst is used, an alkali separation / purification step such as washing with water is required as a post-process, so that there is a problem that the manufacturing process is complicated and the cost is increased.
In addition, in the case of the method of Patent Document 4, the ratio of directly producing an alkyl ester of a fatty acid from triglyceride is not necessarily sufficiently high. In order to improve the reaction rate, use of various catalysts has been studied. Is the fact.
[0005]
The present invention has been made in view of the above-described circumstances, and does not use an alkali catalyst, and is capable of efficiently producing a fatty acid ester from a fat or oil raw material containing a fat or oil as a main component. It is an object to provide a method and a manufacturing device. Another object of the present invention is to provide a method and an apparatus for producing a fatty acid ester having a mechanism for purifying the obtained fatty acid ester to a quality that can be used as a gas oil alternative fuel.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a method for producing a fatty acid ester according to the present invention (claim 1) includes: (a) a step of hydrolyzing a fat or oil raw material mainly containing fats or oils to produce free fatty acids; A) a step of mixing a fatty acid raw material containing a free fatty acid as a main component obtained in the step (a) with an alcohol, and performing an esterification reaction under a condition where the alcohol is in a supercritical state to form a fatty acid ester. Are provided.
[0007]
After producing a free fatty acid by hydrolyzing a fat or oil raw material mainly containing fats and oils, the fatty acid raw material mainly containing the free fatty acid is mixed with an alcohol, and the ester is mixed under conditions where the alcohol is in a supercritical state. By performing the conversion reaction, it is possible to produce a fatty acid ester more efficiently than in the case of directly esterifying a fat or oil raw material, and it can be used as an alternative fuel from a fat or oil raw material mainly containing fats and oils. It is possible to efficiently produce a suitable fatty acid ester.
In addition, as a method of producing a free fatty acid by hydrolyzing a fat or oil raw material containing a fat or oil as a main component, for example, various known methods described below can be used.
[0008]
(1) A method in which an acid or alkaline chemical substance is used as a catalyst to carry out a hydrolysis reaction of fats and oils by a batch or continuous stirring and mixing device.
(2) A method in which a fat or oil hydrolysis reaction is performed by a batch or continuous stirring and mixing apparatus using an enzyme having a catalytic function having high reaction selectivity.
(3) A method in which an emulsifier is added to fats and oils, and the fats and oils covered with the film of the emulsifier are dispersed as fine oil droplets in an aqueous solution containing an enzyme, so that hydrolysis is efficiently performed.
[0009]
The method for producing a fatty acid ester according to claim 2 is characterized in that the oil / fat raw material is at least one selected from the group consisting of vegetable oil, animal oil, vegetable oil, and waste oil of animal oil.
[0010]
By using the method for producing a fatty acid ester of the present invention, a fatty acid ester can be efficiently produced from the above-described vegetable oil, animal oil, waste oil thereof, and the like.
Note that vegetable oils include rapeseed oil, soybean oil, palm oil, linseed oil, sesame oil, corn oil, and the like, and animal oils include fish oil, cow oil, and pork oil.
[0011]
The method for producing a fatty acid ester according to claim 3 is characterized in that the ratio of the free fatty acid in the fatty acid raw material is 60% by weight or more.
[0012]
By setting the proportion of the free fatty acid in the fatty acid raw material to 60% by weight or more, it becomes possible to efficiently produce a fatty acid ester that can be used as an alternative fuel from a fat or oil raw material containing a fat or oil as a main component, It is meaningful.
[0013]
In addition, the fatty acid ester production apparatus of the present invention (claim 4)
(A) a hydrolysis means for hydrolyzing a fat or oil raw material containing fats or oils as a main component to produce free fatty acids;
(B) a reactor for performing an esterification reaction between the fatty acid raw material mainly composed of free fatty acids and the alcohol hydrolyzed by the hydrolysis means and alcohol under a condition where the alcohol is in a supercritical state. It is characterized by.
[0014]
A hydrolysis means for producing free fatty acids by hydrolyzing fats and oils raw materials, and a fatty acid raw material containing free fatty acids as a main component and alcohol hydrolyzed in the hydrolysis means, under conditions where the alcohol is in a supercritical state. The method for producing a fatty acid ester according to any one of claims 1 to 3 of the present application is surely performed by using a fatty acid ester producing apparatus having a reactor for performing an esterification reaction in the present invention. It is possible to efficiently produce a fatty acid ester from a raw material.
[0015]
Further, in the fatty acid ester production apparatus according to the fifth aspect, the reactor is continuously esterified by allowing the mixed fluid of the fatty acid raw material and the alcohol to pass through by mutually dissolving under the condition that the alcohol is in a supercritical state. It is characterized by being a tubular reactor for carrying out the reaction.
[0016]
In the apparatus for producing a fatty acid ester according to claim 5, a tubular reactor is used, and a mixed fluid of a fatty acid raw material and an alcohol (solvent) is mixed at a temperature and pressure in a supercritical region of the alcohol. Since the esterification reaction is performed by passing through the inside, it is possible to continuously and efficiently dissolve and react the fatty acid raw material and the alcohol with each other. Therefore, by using the fatty acid ester production apparatus of claim 5, it is possible to efficiently and economically produce the fatty acid ester.
[0017]
That is, when a mixed fluid of a fatty acid raw material and an alcohol (eg, methanol) is heated to a high temperature and a high pressure to be in a supercritical state (a temperature of 240 ° C. or more and a pressure of 8 MPa or more), the methanol becomes a supercritical state methanol. This supercritical methanol is a highly electrically reactive fluid with a high molecular density comparable to liquids, while molecules move violently like a gas, and high-temperature solvolysis and methylation reactions proceed at high speed. Has features. Therefore, a mixed fluid of a fatty acid raw material and an alcohol (for example, methanol) is passed through the inside of the tubular reactor at a temperature and pressure in a supercritical region using a tubular reactor as in claim 5. In addition, the fatty acid raw material and the alcohol can be continuously and very efficiently reacted, and the fatty acid ester can be efficiently and economically produced.
[0018]
Note that the tubular reactor is a broad concept meaning various types of tubular reactors such as a coiled shape and a bellows shape, and there is no particular restriction on its specific structure.
In addition, various heat transfer promotion tubes configured to promote heat transfer inside and outside the tube by providing grooves, irregularities, protrusions, and the like on the inner peripheral surface of the heat transfer portion of the reactor may be used. It is possible.
[0019]
Furthermore, by disposing an in-line mixer or the like in the tubular reactor to make the solvent into a supercritical fluid state with the fatty acid material and the alcohol sufficiently mixed, the alcohol in the supercritical state and the liquid fatty acid material are Can be efficiently mutually dissolved to further promote the esterification reaction.
[0020]
The apparatus for producing a fatty acid ester according to claim 6 is characterized by comprising an alcohol preheater for preheating the alcohol supplied to the tubular reactor to a temperature lower than its critical temperature.
[0021]
By providing an alcohol preheater that preheats the alcohol supplied to the tubular reactor to a temperature below its critical temperature, the alcohol that forms the main part of the fluid supplied to the tubular reactor is efficiently preheated. As a result, the size of the tubular reactor can be reduced. The reason that the alcohol is preheated to a temperature lower than the critical temperature is that the alcohol can be kept in a liquid phase by preheating the temperature to a temperature lower than the critical temperature, and the fatty acid raw material in the liquid phase is also used. This makes it possible to improve the mixing and dispersion with, and promote the mutual dissolution and the esterification reaction in the subsequent heating process.
[0022]
Further, the fatty acid ester production apparatus according to claim 7 includes a fatty acid raw material preheater for preheating the fatty acid raw material, an alcohol preheater for preheating alcohol to a temperature lower than the critical temperature, and a fatty acid raw material preheater and an alcohol preheater. It is characterized in that a mixing heater is provided for raising the temperature to a reaction temperature at which the alcohol becomes a supercritical state while mixing the fatty acid raw material and the alcohol in a liquid phase.
[0023]
A fatty acid raw material preheater for preheating the fatty acid raw material, an alcohol preheater for preheating the alcohol to a temperature lower than the critical temperature, and a mixture of the fatty acid raw material and the alcohol preheated in the fatty acid raw material preheater and the alcohol preheater in a liquid state. With a configuration having a mixing heater for raising the reaction temperature to a reaction temperature at which alcohol becomes a supercritical state, the entire fluid supplied to the tubular reactor is efficiently preheated, and the tubular reactor is cooled. It is possible to reduce the size.
That is, as in the fatty acid ester production apparatus according to claim 7, the fatty acid raw material and the alcohol preheater are separately preheated with the fatty acid raw material and the alcohol, and then mixed in a liquid state in a mixing heater. By raising the temperature to the reaction temperature at which the alcohol becomes a supercritical state, the decomposition of triglyceride contained in the fatty acid raw material to free fatty acids in the fatty acid raw material preheater is promoted by the fatty acid raw material preheater. By mixing the fatty acid raw material and the alcohol in the liquid state preheated to a temperature below the critical temperature, mutual dissolution and esterification reaction are promoted in the subsequent heating process, and sufficient reaction efficiency is obtained. As a result, the size of the tubular reactor can be reduced.
In addition, as a mixing heater for mixing a fatty acid raw material and an alcohol in a liquid phase, for example, a configuration using a tube-type mixing heater having an in-line mixer is exemplified.
[0024]
Further, the fatty acid ester production apparatus according to claim 8 distills the reaction solution after the esterification reaction in the tubular reactor to produce a low-boiling component containing alcohol and water as main components, a fatty acid ester, glycerin, and It is characterized by comprising distillation means for separating high-boiling components containing high-boiling impurities.
[0025]
By providing a distillation means, by distilling the reaction solution after the esterification reaction in the tubular reactor, a low-boiling component containing alcohol and water as main components, and a high-boiling point containing fatty acid ester, glycerin, and high-boiling impurities The components can be efficiently separated.
By using a flash distillation means as the distillation means, it becomes possible to perform distillation using the temperature and pressure of the reaction solution after the esterification reaction in the tubular reactor, and it is possible to perform distillation with a low boiling point component and a high boiling point. The components can be efficiently separated.
[0026]
The apparatus for producing a fatty acid ester according to claim 9 is characterized in that the high boiling component (fatty acid ester, fatty acid ester, glycerin, and high boiling point impurities) separated by distilling the reaction solution after the esterification reaction by the distillation means. Ester-containing liquid) by distillation of high-boiling impurities to remove high-boiling impurities, and a liquid containing fatty acid esters and glycerin from which high-boiling impurities have been removed, by a mechanical separation method without a phase change, It is characterized by comprising a separation means for separating fatty acid esters and glycerin.
[0027]
A high-boiling-point impurity removing means for removing high-boiling-point impurities by distilling a high-boiling-point component (fatty-acid-ester-containing liquid); By a configuration having a separation means for separating the fatty acid ester and glycerin by a simple separation method, compared with the case of using a separation method such as distillation that involves a phase change in the separation of the fatty acid ester and glycerin, It is possible to efficiently produce a highly pure fatty acid ester with low energy consumption. Note that the mechanical separation method is a concept meaning a separation method utilizing a specific gravity difference like a centrifugal separator, and there is no particular restriction on a specific device type.
[0028]
Further, the fatty acid ester production apparatus according to claim 10 is characterized in that the reaction solution after the esterification reaction in the tubular reactor is distilled to remove the low-boiling components mainly composed of alcohol and water. A fatty acid removing means for separating and removing fatty acids contained in high-boiling components containing glycerin, glycerin and high-boiling impurities by a neutralization reaction with alkali.
[0029]
After the removal of the low-boiling components, the fatty acid contained in the high-boiling components is separated by a neutralization reaction with alkali to remove fatty acids. It is possible to obtain.
[0030]
Further, the apparatus for producing a fatty acid ester according to claim 11 is provided with an alcohol recovery means for recovering alcohol by distilling the low boiling component separated by distilling the reaction solution after the esterification reaction by the distillation means. It is characterized by.
[0031]
By recovering alcohol by distilling low-boiling components by the alcohol recovery means, it becomes possible to recover high-purity alcohol, and if this alcohol is recycled for the esterification reaction, the cost of chemicals is reduced. Can be reduced. Examples of the alcohol recovery means (distillation method) include, but are not limited to, a method of performing distillation using a packed tower, a flash distillation tower, a thin-film distillation tower, and the like.
[0032]
Further, the apparatus for producing a fatty acid ester according to claim 12 is
The temperature conditions and pressure conditions of the tubular reactor are as follows:
Temperature: 250-350 ° C
Pressure: 15 to 25 MPa
It is characterized by being in the range.
[0033]
By setting the temperature and pressure conditions of the tubular reactor in the range of temperature: 250 to 350 ° C. and pressure: 15 to 25 MPa, the alcohol can be surely brought into the supercritical state. I can summarize it.
When the temperature of the tubular reactor is lower than 250 ° C., it is necessary to reheat the triglyceride contained in the fatty acid raw material to a temperature at which the esterification reaction is sufficiently generated without the fatty acid being converted into a fatty acid. Is not preferred. If the temperature of the tubular reactor exceeds 350 ° C., it is difficult to secure a heat source in the actual apparatus, which leads to a remarkable increase in equipment cost, which is not preferable. Not preferred.
Further, when the pressure is less than 15 MPa, the esterification reaction in the next step becomes insufficient, and when the pressure exceeds 25 MPa, the equipment cost is remarkably increased, which is not desirable.
[0034]
Further, the fatty acid ester producing apparatus according to claim 13 is characterized in that a liquid hourly space velocity in the tubular reactor is in a range of 0.3 to 0.03 [1 / min].
[0035]
By setting the liquid hourly space velocity in the tubular reactor to 0.3 to 0.03 [1 / min], the esterification reaction can be sufficiently performed. It is desirable to adjust the liquid space velocity according to the state of the fatty acid raw material and the like.
It is preferable that the liquid hourly space velocity in the tubular reactor be 0.3 to 0.03 [1 / min] because the reaction time is long when the liquid hourly space velocity is less than 0.03 [1 / min]. It is too likely to cause decomposition due to heat depending on the type of fatty acid, and if it exceeds 0.3 [1 / min], the reaction time is shortened and sufficient esterification reaction is not performed. .
[0036]
Further, the fatty acid ester production apparatus of claim 14 is
Temperature conditions and pressure conditions of the fatty acid raw material preheater and the mixing heater,
Temperature: 200-350 ° C
Pressure: 15 to 25 MPa
It is characterized by being in the range.
[0037]
By setting the temperature condition and the pressure condition in the fatty acid raw material preheater and the mixing heater in the temperature range of 200 to 350 ° C. and the pressure of 15 to 25 MPa, the fluid supplied to the tubular reactor can be supplied to the tubular reactor. It is possible to reduce the size of the tubular reactor by preheating so as to correspond to the reaction conditions in (1).
In addition, when the fatty acid raw material is preheated in the fatty acid raw material preheater under the above conditions, not only preparation for supply to the mixing heater is performed, but also hydrolysis of fats and oils is usually performed by contained moisture. Occurs, and glycerides, which are the main components, are decomposed into fatty acids, so that the esterification reaction can be promoted.
[0038]
The apparatus for producing a fatty acid ester according to claim 15 is characterized in that a lower alcohol having 1 to 5 carbon atoms is used as the alcohol.
[0039]
By using a lower alcohol having 1 to 5 carbon atoms as the alcohol, the alcohol can be brought into a supercritical state under practicable temperature and pressure conditions, and the present invention can be made effective. Examples of the lower alcohol having 1 to 5 carbon atoms include methanol, ethanol, propanol, butanol, pentanol and the like.
[0040]
The apparatus for producing a fatty acid ester according to claim 16 is characterized in that it is used for producing a fatty acid ester used as a fuel.
[0041]
According to the fatty acid ester manufacturing apparatus of the sixteenth aspect, it is possible to efficiently manufacture a fatty acid ester used as a fuel (light oil alternative fuel) from various oil and fat raw materials such as vegetable oil, animal oil, and waste oil thereof.
[0042]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described, and features thereof will be described in more detail.
FIG. 1 shows a hydrolysis means A1 for hydrolyzing a fat or oil raw material mainly containing fats and oils to produce free fatty acids, and a fatty acid raw material mainly containing free fatty acid hydrolyzed by the hydrolysis means and an alcohol ( FIG. 2 is a view showing a reaction mechanism section A2 including a tubular reactor for causing an esterification reaction of a (solvent) and its peripheral devices.
FIG. 2 shows a reaction mixture after the esterification reaction performed in a tubular reactor, which is distilled to obtain a low-boiling component mainly composed of alcohol and water, and a high-boiling component containing fatty acid ester, glycerin, and high-boiling impurities. Distillation means B for separating components, alcohol recovery means C for distilling low boiling components separated by distillation means B to recover alcohol, and fatty acids for separating and removing a small amount of fatty acids contained in high boiling components by a neutralization reaction FIG. 4 is a view showing a removing unit D.
FIG. 3 shows a high-boiling impurity removing means E for removing high-boiling impurities by distilling high-boiling components separated by the distillation means B (FIG. 2), and a fatty acid ester from which high-boiling impurities have been removed by the high-boiling impurity removing means. It is a figure which shows the separation means F which separates the liquid containing glycerin into fatty acid ester and glycerin.
[0043]
As shown in FIGS. 1 to 3, the fatty acid ester production apparatus of the present invention comprises a hydrolysis unit A1 for hydrolyzing a fat or oil raw material containing a fat or oil as a main component to produce a free fatty acid; A tubular reaction in which a mixed fluid of a fatty acid raw material mainly composed of free fatty acids and an alcohol hydrolyzed in A1 and an alcohol are passed under a condition where the alcohol is in a supercritical state, whereby an esterification reaction is continuously performed. A reaction mechanism section A2 (FIG. 1) composed of the vessel 4 and its peripheral devices; and a distillation means B for distilling the reaction solution after the esterification reaction in the tubular reactor 4 to separate it into a low-boiling component and a high-boiling component. Alcohol recovery means C for distilling low boiling components to recover alcohol, fatty acid removing means D for separating and removing a small amount of fatty acids contained in high boiling components by a neutralization reaction (FIG. 2); High-boiling-point impurities removing means E for removing high-boiling-point impurities by distilling the high-boiling-point impurities, and separating means F (FIG. 3) ).
[0044]
In the fatty acid ester production apparatus, as the hydrolysis means A1, an emulsifier is added to a fat or oil raw material, and the fat or oil covered with the emulsifier film is dispersed as fine oil droplets in an aqueous solution containing an enzyme, whereby the fat or oil is hydrolyzed. A decomposition method is used.
The reaction mechanism section A2 (FIG. 1) includes a fatty acid raw material tank 1 for storing a fatty acid raw material mainly containing free fatty acids after hydrolyzing an oil raw material mainly containing fats and oils, and an alcohol (methanol) tank 2 The fatty acid raw material preheater 3a for preheating the fatty acid raw material, the alcohol preheater 3b for preheating the alcohol to a temperature below the critical temperature, the fatty acid raw material and the alcohol preheated in the fatty acid raw material preheater 3a and the alcohol preheater 3b, in the liquid state. A mixing heater 3c having a stirring mechanism (in this embodiment, an in-line mixer (not shown)) for raising the temperature to a reaction temperature at which the alcohol becomes a supercritical state while mixing, a mixed fluid of the fatty acid raw material and the alcohol. And a tubular reactor 4 for continuously performing an esterification reaction by passing through.
[0045]
The tubular reactor 4 has a tubular reactor body 4a in which a pipe of a predetermined length is bent in a zigzag manner, and a mixed fluid (raw fluid) of a fatty acid raw material and an alcohol in a supercritical region of the alcohol. A heater 4b is provided for heating or raising the temperature to a predetermined temperature and pressure, or for maintaining the temperature and pressure at the predetermined temperature and pressure. The heater type is not limited to a heating type such as a double-tube heating type using a heat medium or high-pressure steam or an electric heater type.
[0046]
In addition, it is also possible to provide a heat recovery unit 5 that recovers heat by preheating the alcohol by causing heat exchange between the liquid after the reaction and alcohol, for example, at the outlet side of the tubular reactor 4. There is no special restriction on the presence or absence of the heat recovery unit 5 and the specific configuration when the heat recovery unit is provided.
[0047]
As shown in FIG. 2, a distillation means B (FIG. 2) for distilling low boiling components from the reaction solution after the esterification reaction in the tubular reactor 4 to separate low boiling components and high boiling components is provided by a pipe A decompression system 11 disposed on the outlet side of the mold reactor 4, a flash can 13a for flash-evaporating a reaction liquid (reacted liquid) exiting the decompression system 11, a buffer tank 12 for receiving the decompressed reaction liquid, Evaporation for distilling low-boiling components mainly composed of alcohol and water from the reaction solution supplied from the buffer tank 12 to separate low-boiling components and high-boiling components containing fatty acid esters, glycerin, and high-boiling impurities Unit 13b, a high-boiling component tank 14 for receiving high-boiling components not evaporated in the evaporating unit 13b, and the vapor of alcohol and water evaporated in the flash can 13a and the evaporating unit 13b. A capacitor 15 to be reduced, and a low-boiling component tank 16 which receives the low-boiling components consisting of alcohol and water condensed in the condenser 15.
[0048]
Further, the alcohol recovery means C (FIG. 2) for recovering alcohol by distilling the low-boiling components separates the low-boiling components consisting of alcohol and water supplied from the low-boiling component tank 16 into alcohol and water. The apparatus includes a distillation column 21 and a condenser 22 for condensing alcohol vapor as a distillate.
[0049]
Further, the fatty acid removing means D for separating and removing a small amount of fatty acids contained in the high-boiling components by a neutralization reaction is provided with alkali in the line sent from the high-boiling component tank 14 of the distillation means B which receives the high-boiling components. A separator 23 is provided for performing neutralization reaction and separation in a mechanical separator by adding a line. Then, in the separator 23, fatty acid soap, which is a neutralized impurity, is separated. As the separator 23, it is possible to use a centrifugal separator or various mechanical separators other than the centrifugal separator.
[0050]
The high-boiling impurity removing means E for distilling high-boiling components to remove high-boiling impurities removes fatty acid esters and glycerin, and separates unreacted products and polymers (high-boiling impurities) as bottoms. A distilling device 31 comprising a thin film descending type heater and evaporator, and a condenser 32 for condensing the distilled fatty acid ester and glycerin are provided. It should be noted that the distillation unit 31 is not limited to a thin-film descending type comprising a heater and an evaporator, and various types can be used.
Note that a trap 35 is provided in the vacuum line 34 on the downstream side of the condenser 32.
[0051]
Separation means F (FIG. 3) for separating high-boiling components containing fatty acid esters and glycerin into fatty acid esters and glycerin after removing high-boiling impurities from the high-boiling components is supplied from the condenser 32 and the trap 35. There is provided a separator 36 for separating a liquid containing a fatty acid ester and glycerin into a fatty acid ester and glycerin by a specific gravity difference using centrifugal force. The separator 36 is not limited to a centrifugal separator, and other types of mechanical separators may be used.
[0052]
In this embodiment, a water-sealed vacuum pump with a gas ejector is used as the vacuum suction means 37. However, the type of the vacuum suction means 37 is not particularly limited, and another type can be used.
[0053]
【Example】
Hereinafter, the features of the present invention will be described more specifically with reference to examples of the present invention.
[0054]
[Example 1]
Using the fatty acid ester manufacturing apparatus configured as described above, a raw material containing a large amount of triglyceride was treated under the following conditions.
[0055]
(1) Properties of fat and oil raw materials
Triglyceride content: about 90-98% by weight
Free fatty acid content: about 2 to 10% by weight
(2) Properties of fatty acid raw material after hydrolyzing oil / fat raw material and separating from aqueous phase
Triglyceride content: about 25-30% by weight
Free fatty acid content: about 60 to 75% by weight
Moisture content: about 1-2% by weight
(3) Types of alcohol (solvent)
methanol
(4) Reaction conditions
Reaction temperature: 300 ° C
Reaction pressure: 15-22 MPa
Liquid space velocity: about 0.08 to 0.13 1 / min
Solvent addition rate: about 0.5 to 1.0 weight times the fatty acid raw material
[0056]
Then, methanol and water as a solvent were distilled off from the reaction solution, and fatty acid esters recovered by removing high boiling impurities were analyzed by gas chromatography and gas chromatography / mass spectrometry.
[0057]
Composition of recovered fatty acid esters (analysis results)
Palmitate: 6.0%
Oleic and stearic acid esters: 44.5%
Linoleic acid ester: 19.3%
Linolenic acid ester: 5.8%
Other fatty acid ester products: 15.2%
Glycerin: 0.8%
Water content: 0.05%
Other: remaining
[0058]
As described above, the fatty acid species of the detected fatty acid esters are mainly palmitic acid, oleic acid, linoleic acid, linolenic acid, and stearic acid, and in addition, some fatty acid esterified products whose fatty acid species cannot be identified It was confirmed that about 90% of the fatty acid ester could be finally recovered by performing the distillation operation.
[0059]
From the above analysis results, it was confirmed that the esterification reaction had sufficiently proceeded, and that the substances other than the fatty acid esterified product were glycerin, trace water, and monoglycerin fatty acid ester.
[0060]
From Example 1, it was confirmed that a fatty acid ester having a quality that can be used as a target gas oil alternative fuel can be obtained from an oil or fat raw material containing a large amount of triglyceride.
In addition, the collected methanol was also analyzed, and it was confirmed that the methanol was of a quality that could be recycled.
[0061]
[Example 2]
Rapeseed oil and soybean oil having a triglyceride ratio of 99% by weight or more were treated as oil and fat raw materials under the same conditions as in Example 1 above.
[0062]
(1) Fat and oil raw materials
Rapeseed oil and white soybean oil (triglyceride over 99% by weight)
(2) Properties of fatty acid raw material after hydrolyzing oil / fat raw material and separating from aqueous phase
Triglyceride content: about 13-38% by weight
Free fatty acid content: about 60 to 85% by weight
Moisture content: about 1-2% by weight
(3) Types of alcohol
methanol
(4) Reaction conditions
Reaction temperature: 300-330 ° C
Reaction pressure: 15-22 MPa
Liquid space velocity: about 0.08 to 0.13 1 / min
Solvent addition rate: about 1.0 to 1.6 times the weight of fatty acid raw material
Other conditions are the same as those in the first embodiment.
[0063]
As a result of treating white rapeseed oil (99% by weight or more of triglyceride) of rapeseed oil and soybean oil under the above conditions, it was confirmed that substantially the same results as in Example 1 were obtained.
It has also been confirmed that the recovered methanol is recyclable.
[0064]
In the above embodiment, methanol is used as the alcohol, but other lower alcohols having 2 to 5 carbon atoms, for example, ethanol, propanol, butanol, pentanol and the like can also be used.
[0065]
Further, in the above embodiment, the alcohol (methanol) is preheated, but it is also possible to configure so as to preheat a mixed fluid obtained by mixing the fatty acid raw material and the alcohol.
[0066]
Further, in the above-described embodiment, the case where the fat and oil raw material containing a large amount of triglyceride (Example 1) and the white squeezed oil of rapeseed oil and soybean oil (Example 2) are described as an example, but other vegetable oils and animal oils are used. It is also possible to treat such waste oils.
[0067]
The present invention is not limited to the above embodiments and examples in still other respects, and includes temperature conditions and pressure conditions such as a tubular reactor, a preheater, and a mixing heater, and the like in the tubular reactor. Regarding the liquid space velocity, various applications and modifications can be made within the scope of the invention.
[0068]
【The invention's effect】
As described above, in the method for producing a fatty acid ester of the present invention (claim 1), a free fatty acid is generated by hydrolyzing a fat or oil raw material containing a fat or oil as a main component, and then producing the free fatty acid as a main component. The fatty acid raw material and the alcohol are mixed, and the esterification reaction is performed under the condition that the alcohol is in a supercritical state, so that the fatty acid ester is generated more efficiently than in the case of directly esterifying the fat or oil raw material. It is possible to efficiently produce a fatty acid ester that can be used as an alternative fuel from a fat or oil raw material containing a fat or oil as a main component.
[0069]
Further, as in the method for producing a fatty acid ester according to claim 2, when the oil or fat raw material is at least one selected from the group consisting of vegetable oil, animal oil, vegetable oil or waste oil of animal oil, the present invention is applied to improve efficiency. It becomes possible to produce fatty acid esters well.
[0070]
Further, as in the method for producing a fatty acid ester according to claim 3, by setting the proportion of free fatty acid in the fatty acid raw material to 60% by weight or more, it is possible to use the oil / fat raw material mainly composed of fat / oil as an alternative fuel. It is possible to efficiently produce a fatty acid ester, which is particularly significant.
[0071]
In addition, the fatty acid ester production apparatus of the present invention (claim 4) comprises a hydrolysis means for hydrolyzing a raw material of fats and oils to produce free fatty acids, and a free fatty acid hydrolyzed by the hydrolysis means as a main component. Since a fatty acid raw material and an alcohol are provided with a reactor for performing an esterification reaction under a condition where the alcohol is in a supercritical state, the method for producing a fatty acid ester according to claims 1 to 3 of the present application is surely performed. Thus, it is possible to efficiently produce a fatty acid ester from a fat or oil raw material containing a fat or oil as a main component.
[0072]
Further, as in the fatty acid ester production apparatus of claim 5, a mixed fluid of a fatty acid raw material and an alcohol (solvent) is supplied to a tubular reactor by using a tubular reactor under the temperature and pressure of a supercritical region of alcohol. When the esterification reaction is carried out by passing through the inside, the fatty acid raw material and the alcohol can be continuously and efficiently mutually dissolved and reacted. Therefore, by using the fatty acid ester production apparatus of claim 5, it is possible to efficiently and economically produce the fatty acid ester.
[0073]
That is, when a mixed fluid of a fatty acid raw material and an alcohol (eg, methanol) is heated to a high temperature and a high pressure to be in a supercritical state (a temperature of 240 ° C. or more and a pressure of 8 MPa or more), the methanol becomes a supercritical state methanol. This supercritical methanol is a highly electrically reactive fluid with a high molecular density comparable to liquids, while molecules move violently like a gas, and high-temperature solvolysis and methylation reactions proceed at high speed. Has features. Therefore, a mixed fluid of a fatty acid raw material and an alcohol (for example, methanol) is passed through the inside of the tubular reactor at a temperature and pressure in a supercritical region using a tubular reactor as in claim 5. In addition, the fatty acid raw material and the alcohol can be continuously and very efficiently reacted, and the fatty acid ester can be efficiently and economically produced.
[0074]
Furthermore, by disposing an in-line mixer or the like in the tubular reactor to make the solvent into a supercritical fluid state with the fatty acid material and the alcohol sufficiently mixed, the alcohol in the supercritical state and the liquid fatty acid material are Can be efficiently mutually dissolved to further promote the esterification reaction.
[0075]
Further, as in the fatty acid ester production apparatus according to claim 6, the alcohol supply to the tubular reactor is provided with an alcohol preheater for preheating the alcohol to a temperature lower than its critical temperature, whereby the tubular reactor is provided. It is possible to efficiently preheat alcohol, which is a main part of the fluid supplied to the reactor, to reduce the size of the tubular reactor.
[0076]
Further, as in the fatty acid ester production apparatus of claim 7, a fatty acid raw material preheater for preheating the fatty acid raw material, an alcohol preheater for preheating the alcohol to a temperature lower than the critical temperature, a fatty acid raw material preheater and an alcohol preheater. By mixing the preheated fatty acid raw material and alcohol in a liquid phase while mixing the mixture in a liquid phase, the mixture is heated to a reaction temperature at which the alcohol becomes a supercritical state. It is possible to efficiently preheat the entire fluid and reduce the size of the tubular reactor.
That is, as in the fatty acid ester production apparatus according to claim 7, the fatty acid raw material and the alcohol preheater are separately preheated with the fatty acid raw material and the alcohol, and then mixed in a liquid state in a mixing heater. By raising the temperature to the reaction temperature at which the alcohol becomes supercritical, mutual dissolution and esterification reactions are promoted, ensuring sufficient reaction efficiency and reducing the size of the tubular reactor. Becomes possible.
[0077]
Further, as in the fatty acid ester production apparatus according to claim 8, a distillation means is provided, and the reaction solution after the esterification reaction in the tubular reactor is distilled, whereby a low-boiling component containing alcohol and water as main components. Thus, high-boiling components containing fatty acid esters, glycerin, and high-boiling impurities can be efficiently separated.
By using a flash distillation means as the distillation means, it becomes possible to perform distillation using the temperature and pressure of the reaction solution after the esterification reaction in the tubular reactor, and it is possible to perform distillation with a low boiling point component and a high boiling point. The components can be efficiently separated.
[0078]
A high-boiling-point impurity removing means for removing high-boiling-point impurities by distilling a high-boiling-point component (a fatty-acid-ester-containing liquid), as in the fatty-acid ester producing apparatus according to claim 9, and a fatty-acid ester from which high-boiling-point impurities have been removed. And a separation means for separating the liquid containing fatty acid ester and glycerin into a fatty acid ester and glycerin by a mechanical separation method that does not involve a phase change. Compared with the case where a separation method such as distillation is used, it is possible to efficiently produce a highly pure fatty acid ester with less energy consumption.
[0079]
Further, as in the apparatus for producing a fatty acid ester according to claim 10, after removing the low-boiling components, there is provided a fatty acid removing means for separating and removing the fatty acids contained in the high-boiling components by a neutralization reaction with alkali. By doing so, it is possible to obtain a high-quality fatty acid ester containing almost no fatty acid, which is significant.
[0080]
Further, as in the fatty acid ester production apparatus according to the eleventh aspect, by recovering the alcohol by distilling the low boiling point component by the alcohol recovery means, it becomes possible to recover the alcohol with high purity, When is recycled for the esterification reaction, the cost of the drug can be reduced.
[0081]
Further, as in the fatty acid ester production apparatus of the twelfth aspect, the temperature and pressure conditions of the tubular reactor are set to a temperature range of 250 to 350 ° C. and a pressure range of 15 to 25 MPa. A supercritical state can be obtained, and the present invention can be effectively demonstrated.
[0082]
Further, as in the apparatus for producing a fatty acid ester according to the thirteenth aspect, by setting the liquid hourly space velocity in the tubular reactor to 0.3 to 0.03 [1 / min], the esterification reaction is sufficiently performed. It becomes possible.
[0083]
Further, as in the fatty acid ester production apparatus of claim 14, the temperature condition and the pressure condition in the fatty acid raw material preheater and the mixing heater are set to a temperature range of 200 to 350 ° C. and a pressure range of 15 to 25 MPa. In addition, the fluid supplied to the tubular reactor is preheated so as to correspond to the reaction conditions in the tubular reactor, thereby making it possible to reduce the size of the tubular reactor.
[0084]
Further, as in the fatty acid ester production apparatus of claim 15, by using a lower alcohol having 1 to 5 carbon atoms as the alcohol, the alcohol can be brought into a supercritical state under practical temperature and pressure conditions. It becomes possible, and the present invention can be made effective.
[0085]
According to the fatty acid ester production apparatus of the sixteenth aspect, it is possible to efficiently produce a fatty acid ester used as a fuel (light oil alternative fuel) from various oils and fats such as vegetable oils, animal oils, and waste oils thereof. Become.
[Brief description of the drawings]
FIG. 1 is a view showing a hydrolysis means and a reaction mechanism of a fatty acid ester production apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating an apparatus for producing a fatty acid ester according to an embodiment of the present invention, in which a reaction solution is distilled to obtain a low-boiling component containing alcohol and water as main components, and a high-boiling component containing fatty acid ester, glycerin, and high-boiling impurities. Distillation means for separating the boiling components, alcohol recovery means for distilling the low boiling components to recover alcohol, and fatty acid removing means for separating and removing a small amount of fatty acids contained in the high boiling components separated by distillation by a neutralization reaction. FIG.
FIG. 3 shows a high-boiling-point impurity removing means for distilling high-boiling-point components to remove high-boiling-point impurities and a fatty-acid ester from which high-boiling-point impurities have been removed. FIG. 4 is a diagram showing a separation means for separating a liquid containing glycerin and glycerin into fatty acid esters and glycerin.
[Explanation of symbols]
A1 hydrolysis means
A2 Reaction mechanism
B distillation means
C alcohol recovery means
D means for removing fatty acids
E means for removing high boiling impurities
F separation means
1 Fatty acid raw material tank
2 Alcohol (methanol) tank
3a Fatty acid raw material preheater
3b Alcohol preheater
3c mixing heater
4 tube reactor
4a Reactor body
4b heater
5 Heat recovery section
11 Decompression system
12 buffer tank
13a Flash can
13b Evaporation section
14. High boiling point component tank
15 Capacitor
16 Low boiling point component tank
21 Distillation tower
22 capacitors
23 Separator
31 still
32 capacitors
34 vacuum line
35 trap
36 Separator
37 Vacuum suction means (sealed vacuum pump with gas ejector)

Claims (16)

(A) a step of hydrolyzing a fat or oil raw material mainly containing fats and oils to produce free fatty acids; (b) a fatty acid raw material mainly containing free fatty acid obtained in the above step (a); And subjecting the mixture to an esterification reaction under a condition in which the alcohol is in a supercritical state to produce a fatty acid ester. The method for producing a fatty acid ester according to claim 1, wherein the fat or oil raw material is at least one selected from the group consisting of vegetable oil, animal oil, vegetable oil, and waste oil of animal oil. The method for producing a fatty acid ester according to claim 1 or 2, wherein a ratio of the free fatty acid in the fatty acid raw material is 60% by weight or more. (A) a hydrolyzing means for producing free fatty acids by hydrolyzing a fat or oil raw material mainly containing fats and oils, and (b) a fatty acid mainly containing free fatty acids hydrolyzed in the hydrolysis means. An apparatus for producing a fatty acid ester, comprising: a reactor for performing an esterification reaction between a raw material and alcohol under a condition in which the alcohol is in a supercritical state. The reactor is a tubular reactor that continuously performs an esterification reaction by allowing a mixed fluid of the fatty acid raw material and the alcohol to mutually dissolve and pass under a condition in which the alcohol is in a supercritical state. An apparatus for producing a fatty acid ester according to claim 4. The apparatus for producing a fatty acid ester according to claim 5, further comprising an alcohol preheater that preheats the alcohol supplied to the tubular reactor to a temperature equal to or lower than the critical temperature. The fatty acid raw material preheater for preheating the fatty acid raw material, the alcohol preheater for preheating alcohol to a temperature lower than the critical temperature, the fatty acid raw material preheater and the fatty acid raw material preheated in the alcohol preheater are mixed in a liquid state. The fatty acid ester production apparatus according to claim 4 or 5, further comprising a mixing heater for raising the temperature of the alcohol to a reaction temperature at which the alcohol becomes a supercritical state. Distillation means for distilling the reaction solution after the esterification reaction in the tubular reactor to separate a low-boiling component containing alcohol and water as main components and a high-boiling component containing fatty acid ester, glycerin, and high-boiling impurities. The fatty acid ester production apparatus according to any one of claims 4 to 7, comprising: The high boiling components (fatty acid ester-containing liquid) containing fatty acid esters, glycerin, and high boiling impurities separated by distilling the reaction solution after the esterification reaction by the distillation means are removed to remove the high boiling impurities. A high-boiling-point impurity removing means, and a separating means for separating the liquid containing the fatty acid ester from which the high-boiling-point impurities have been removed and glycerin into a fatty acid ester and glycerin by a mechanical separation method that does not involve a phase change. The apparatus for producing a fatty acid ester according to any one of claims 4 to 8, wherein Distillation of the reaction solution after the esterification reaction in the tubular reactor, after removing low-boiling components having alcohol and water as main components, into fatty acid esters, glycerin, and high-boiling components containing high-boiling impurities The fatty acid ester producing apparatus according to any one of claims 4 to 9, further comprising a fatty acid removing means for separating and removing the fatty acids contained therein by a neutralization reaction with an alkali. The method according to any one of claims 4 to 10, further comprising an alcohol recovery means for recovering the alcohol by distilling the low boiling component separated by distilling the reaction solution after the esterification reaction by the distillation means. An apparatus for producing the fatty acid ester according to the above. The temperature conditions and pressure conditions of the tubular reactor are as follows:
Temperature: 250-350 ° C
Pressure: 15 to 25 MPa
The apparatus for producing a fatty acid ester according to any one of claims 5 to 11, wherein The fatty acid ester production apparatus according to any one of claims 5 to 12, wherein a liquid hourly space velocity in the tubular reactor is in a range of 0.3 to 0.03 [1 / min]. Temperature conditions and pressure conditions of the fatty acid raw material preheater and the mixing heater,
Temperature: 200-350 ° C
Pressure: 15 to 25 MPa
The fatty acid ester production apparatus according to any one of claims 7 to 13, wherein: The fatty acid ester production apparatus according to any one of claims 4 to 14, wherein a lower alcohol having 1 to 5 carbon atoms is used as the alcohol. The fatty acid ester production apparatus according to any one of claims 4 to 15, which is used for producing a fatty acid ester used as a fuel.

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