WO2006121021A1

WO2006121021A1 - Process for producing fatty acid ester and process for producing glycerol

Info

Publication number: WO2006121021A1
Application number: PCT/JP2006/309273
Authority: WO
Inventors: Shoji Morita; Katsuhiko Tomashino
Original assignee: Toray Industries, Inc.
Priority date: 2005-05-13
Filing date: 2006-05-09
Publication date: 2006-11-16

Abstract

A process for producing a fatty acid ester from a fat and a monohydric alcohol with a chemical catalyst, which comprises continuously feeding an excess of a monohydric alcohol in the state of superheated vapor to a reaction system to cause the alcohol to undergo transesterification with a fat, continuously discharging a fatty-acid-ester-containing reaction product in the state of a vapor phase or a mixed phase comprising the vapor phase and a droplet state phase together with the monohydric alcohol in a superheated vapor state, and separating and recovering the fatty acid ester. It is a simple process by which high-purity products (a fatty acid ester and glycerol) can be obtained at low cost and high reaction efficiency without the need of a catalyst separation step.

Description

Specification

Method for producing fatty acid ester and method for producing glycerin

Technical field

[0001] The present invention relates to a useful method for producing a fatty acid ester or glycerin by reacting a triglyceride contained in fats and oils with an alcohol for transesterification, and an ester exchange reaction apparatus used therefor.

Background art

[0002] As one of efforts to comply with carbon dioxide emission regulations, there have been many attempts to use plant-derived fuels as diesel fuels in place of fossil fuels. Palm oil, rapeseed oil, etc., which are usually obtained from plants, are mainly composed of triglycerides, so they have a higher viscosity than light oil, and the relationship between the melting point solidifies in cold regions. Not always appropriate. For this reason, attempts have been made to produce diesel fuel equivalent to diesel oil by transesterifying with triglycerides using alkyl alcohols to obtain fatty acid alkyl esters, and various methods have been proposed. Yes.

[0003] For example, as a method using an organic catalyst, Patent Document 1 proposes a method using an alkali catalyst such as a caustic potash catalyst, a potassium carbonate catalyst, a calcium hydroxide catalyst, etc. Chemical examples are also scattered. However, the methods specifically disclosed in these documents are substantially low in productivity due to batch processing, and it is difficult to recover the catalyst from a mixture of the catalyst and by-product glycerin. Met. Therefore, when these methods are used, there are many cases where the catalyst must be treated as hazardous waste together with glycerin. This type of method is also unsuitable for mass production that can contribute to the force-environment problem applicable to small-scale production.

[0004] On the other hand, in order to improve the production rate, a method of continuous production is disclosed in Patent Document 2, but the recovery of the catalyst, which is still insufficient in productivity even if this method is used, is also described above. There are similar problems.

Patent Document 1: Japanese Patent Laid-Open No. 2003-96473 Patent Document 2: Japanese Patent Laid-Open No. 10-182518

Disclosure of the invention

Problems to be solved by the invention

[0005] In the present invention, a simple production method that solves the problems of the above production method and obtains products (fatty acid ester and glycerin) at low cost, high reaction efficiency, and high purity without a catalyst separation step. The issue is to develop.

Means for solving the problem

[0006] The inventors have made the following invention.

[0007] (1) A method for producing a fatty acid ester from fats and oils and a monohydric alcohol using a chemical catalyst, wherein the excess monohydric alcohol is continuously supplied to the reaction system in the form of superheated steam. The reaction product containing fatty acid ester is continuously withdrawn together with superheated steam of monohydric alcohol in the gas phase or mixed phase with droplet-like phase, The manufacturing method of the fatty acid ester which isolate | separates and collects fatty acid ester.

[0008] (2) The method for producing a fatty acid ester according to (1), wherein the chemical catalyst is an alkali metal compound or a compound of Z and an alkaline earth metal.

[0009] (3) The method for producing a fatty acid ester according to the above (1) or (2), wherein the chemical catalyst is sodium hydroxide sodium or Z and potassium hydroxide hydroxide.

[0010] (4) The amount of the chemical catalyst to be used is any one of the above (1) to (3), wherein the amount is from 0.002 to 0.2 mol relative to 1 kg of the raw material fat and oil stored in the reaction vessel A method for producing fatty acid esters.

[0011] (5) The reaction is carried out at a reaction vessel pressure of about normal pressure, the temperature of alcohol in the superheated steam state is 250 ° C to 350 ° C, and the temperature of fats and oils is 250 ° C to 350 ° C. The method for producing a fatty acid ester according to any one of (1) to (4), which is caused to occur.

[0012] (6) A method for producing glycerin from fats and oils and a monohydric alcohol using a chemical catalyst, wherein the excess monohydric alcohol is continuously supplied to the reaction system in the form of superheated steam. The reaction product containing glycerin is continuously withdrawn together with superheated steam of monohydric alcohol in the gas phase or in the mixed phase with a liquid phase, and the glycerin is separated and recovered. A method for producing glycerin. [0013] (7) A reaction vessel provided with a heating and heat insulation device, an oil and fat supply port provided in the reaction vessel, and a nozzle for supplying alcohol in the form of superheated steam provided below the reaction vessel The above-mentioned (1) to (1) further comprising an outlet for extracting the reaction product in a gas phase provided in the upper part of the reaction vessel or a mixed phase with a droplet-like phase together with superheated steam of monohydric alcohol. An apparatus for transesterification used in the method for producing a fatty acid ester according to any one of (5) or the method for producing glycerin according to (6).

(8) Reaction vessel equipped with a heating and heat insulation device, draft tube, impeller, static mixer, supply port for supplying oils and fats and superheated steam provided in the reaction vessel A nozzle for supplying the alcohol, and a reaction product in a gas phase or a mixed phase with a droplet-like phase provided in the upper part of the reaction vessel together with superheated steam of the -valent alcohol. The mixture of oils and chemicals containing alcohol bubbles in the form of superheated steam and the chemical catalyst is lowered inside the draft tube by the impeller, and the mixture rises outside the draft tube. The fatty acid ester according to any one of (1) to (5), wherein the fatty acid ester is arranged so as to form a circulating flow and to promote gas-liquid contact by passing the mixture through a static mixer. Transesterification reactor used in the manufacturing method also in the production method of glycerin in the (6), wherein.

[9] (9) A temperature control device for superheated steam of monohydric alcohol supplied to the reaction vessel and

The transesterification apparatus according to the above (7) or (8), which is provided with a temperature control device for oil or fat supplied to Z or the reaction vessel.

[0016] (10) Nozzle force for supplying superheated steam of a monohydric alcohol The transesterification reaction apparatus according to any one of (7) to (9), which is installed so as to discharge superheated steam downward in the reaction vessel.

(11) The transesterification apparatus according to any one of (7) to (10), wherein a perforated plate is provided at the nozzle tip.

The invention's effect

[0018] According to the present invention, fatty acid ester and glycerin can be produced with high purity and low cost by a simple apparatus and method.

[0019] In addition, the method of the present invention has a long time since the chemical catalyst remains in the reaction system. Operation without additional supply of chemical catalyst.

Furthermore, in the present invention, fatty acid ester and glycerin can be produced continuously.

Brief Description of Drawings

FIG. 1 is an example of a reactor according to the present invention, and FIG. 1 lb is an example of a nozzle tip in the reactor.

FIG. 2 is an example of a reaction apparatus according to the present invention.

Explanation of symbols

1 container

2a Heating device

2b Heating device

3 nozzles

4 Oil and fat supply pipe

5 Fats and oils

6 Chemical catalyst

7 Alcohol in the state of superheated steam

8 Reaction products

9 Stirrer

10 perforated plate

11 Draft tube

12 Impeller

13 Static mixer

BEST MODE FOR CARRYING OUT THE INVENTION

[0023] The present invention is a method for producing fatty acid esters and glycerin from oils and fats (including waste oils and fats) and monohydric alcohols (hereinafter simply referred to as alcohols) using a chemical catalyst, In this process, excess alcohol is continuously supplied to the reaction system in the form of superheated steam to react with fats and oils, and the reaction product containing fatty acid ester and glycerin is converted into a gas phase or a droplet phase. Continuous extraction with alcohol superheated steam in mixed phase The fatty acid ester and glycerin are separated from each other.

In the present invention, “/ alcohol in the state of superheated steam” refers to an alcohol maintained at a temperature higher than the boiling point corresponding to the pressure of the alcohol.

[0025] The fats and oils used in the present invention include fats and oils having fatty acid ester of glycerin, preferably triglyceride. Such oils and fats include natural plants such as palm oil, rapeseed oil, soybean oil, olive oil, corn oil, peanut oil, coconut oil, safflower oil, sesame oil, hamani oil, castor oil, tung oil, sunflower oil, etc. Oils, pork oil, beef tallow, horse oil, sardine oil, shark oil, whale oil and other animal oils, synthetic oils, etc. These may be waste oils and waste edible oils! /, And can be a mixture of these! /.

[0026] When the above fats and oils, especially waste fats and oils or waste edible oils are used, components other than fats and oils may be mixed. When components other than fats and oils may cause clogging in the manufacturing process or reaction inhibition, it is preferable to remove them in advance by methods such as distillation and filtration.

[0027] The alcohol used in the present invention is preferably a monohydric alcohol having 1 to 3 carbon atoms from the viewpoint of the boiling point and cost of the obtained fatty acid ester. Specific examples include methanol and ethanol, and methanol is particularly preferred when used for diesel fuel.

[0028] The chemical catalyst used in the present invention means a compound having a catalytic activity for transesterification by contacting fats and oils with alcohol, and is a concept that excludes simple metals. Preferable examples of the chemical catalyst used in the present invention include alkali metal compounds and alkaline earth metal compounds, and these can be used alone or in combination.

[0029] Preferably, the alkali metal is one or more selected from potassium and sodium, and the alkaline earth metal is preferably one or more selected from barium, calcium and magnesium. ,.

[0030] The metal compound is one of a metal oxide, a hydroxide, an inorganic acid salt, and an organic acid salt, or contains two or more compounds. Is preferred.

[0031] The inorganic acid salt is preferably a carbonate. [0032] The organic acid salt is preferably a force containing a carboxylic acid group, or one having a hydroxyl group added thereto. Specific examples include potassium palmitate.

[0033] Specific examples of such compounds include sodium hydroxide (caustic soda) and potassium hydroxide.

(Caustic potash), sodium carbonate, potassium carbonate and the like can be preferably mentioned. Of these, caustic soda and caustic potash are preferred from the viewpoint of solubility in the reaction system.

[0034] The amount of the chemical catalyst used in the present invention is from 0.0002 monole to 0.2 monole, preferably from 0.002 monole to 0.05 monole with respect to lKg of the raw material fat and oil stored in the reaction vessel. S is preferred.

[0035] The basic reaction in the production method of the present invention involves contacting an alcohol and fats and oils in the presence of a chemical catalyst to cause a transesterification reaction to produce a fatty acid ester and glycerin. At that time, after excessive alcohol is continuously supplied to the reaction system in the form of superheated steam and reacted in the reaction system, the reaction product containing the fatty acid ester and glycerin is converted into a gas phase or a droplet phase. It is characterized by being continuously extracted out of the reaction system together with the alcohol superheated vapor in the mixed phase state.

[0036] In the above, supplying "excess alcohol" means that the supplied alcohol is not necessarily in excess of the theoretical chemical equivalent necessary for transesterification of the total amount of glycerin ester in the raw oil and fat. It is sufficient that the amount is excessive in comparison with the reaction with nearby oils and fats. Thereby, when the reaction product obtained by the reaction is extracted out of the system, the alcohol in the superheated steam state is also extracted. It is preferable to control the supply amount of alcohol so that the amount of alcohol in the superheated steam state is about 30 to 80% by weight in the mixture of the alcohol and reaction product in the superheated steam state to be extracted.

[0037] In addition, it is preferable to set the pressure in the reaction vessel at the time of reaction to around normal pressure, more preferably from 0.11 to 0.15 OMPa! / ,.

[0038] The temperature of the alcohol in the superheated steam state to be supplied is preferably 250 ° C to 350 ° C, more preferably 270 ° C to 300 ° C. Thereby, the temperature of the fats and oils is preferably set to 250 ° C to 350 ° C, more preferably 270 ° C to 300 ° C.

[0039] Further, a reaction product containing a fatty acid ester and glycerin when extracted from the reaction system; The temperature of the mixture of alcohol superheated steam is preferably 250 ° C to 350 ° C.

[0040] In the present invention, a reaction for supplying an oil and fat with an alcohol in a superheated steam state to cause a transesterification reaction in the presence of a chemical catalyst, and extracting the resulting reaction mixture together with an alcohol in a superheated steam state. As the apparatus, various types of reactors can be used, and specific embodiments are exemplified below.

[0041] First embodiment:

In the first embodiment, a reaction vessel equipped with a heating and heat insulation device, an oil / fat supply port provided in the reaction vessel, and an alcohol in the form of superheated steam provided below the reaction vessel are provided. A transesterification reaction apparatus having a nozzle and an outlet for extracting a reaction product in a gas phase or a mixed phase accompanied by a droplet-like phase provided at the upper part of the reaction vessel together with superheated alcohol vapor It is a form using.

A preferred example of the above embodiment will be described with reference to FIG. 1, but the present invention is not limited to this.

[0043] As shown in Fig. La, a mixture of raw material fats and oils 5 heated to a predetermined temperature and a chemical catalyst (for example, caustic potash) 6 is placed in a stainless steel cylindrical reaction vessel 1 equipped with a heating and heat retaining device. Save. Alcohol 7 in the form of superheated steam heated to a predetermined temperature by the heating device 2a is blown from the nozzle 3, and the reaction product (fatty acid ester and glycerin) 8 is added together with excess superheated steam alcohol from the top of the reaction vessel. Extract. As the reaction proceeds, the raw fats and oils corresponding to the consumed amount are heated to a predetermined temperature by the heating device 2b and supplied from the supply pipe 4. If necessary, stir with stirrer 9. It is preferable that the nozzle tip has a shape to which a multi-hole plate 10 is added. An example of this shape is shown in Fig. Lb.

[0044] The amount of the chemical catalyst (caustic potash) used is 0.

001 Wt% to lWt% is more preferable, and 0.01 Wt% to 0.3 Wt% is more preferable. The temperature of the fats and oils as the raw material is 250 to 350, more preferably 270 ° C to 290 ° C. The temperature of vaporized alcohol in the state of superheated steam to be supplied is preferably 250 ° C to 350 ° C, more preferably 270 ° C to 290 ° C.

[0045] Second Embodiment:

In the second embodiment, a reaction vessel provided with a heating and heat insulation device is provided in the reaction vessel. Draft tube, impeller, static mixer, supply port for supplying oils and fats, nozzle for supplying alcohol in the form of superheated steam, and the gas phase provided at the top of the reaction vessel or it Reaction in the state of mixed phase with droplet-like phase Equipped with outlet for extracting product together with alcohol superheated steam, mixture power of fats and oils containing alcohol bubbles in superheated steam and chemical catalyst The S impeller lowers the inside of the draft tube so that the mixture ascends outside the draft tube, and the gas-liquid contact is promoted by passing through the mixture catalytic mixer. This is a form using a transesterification reactor arranged.

A preferred example of the above embodiment will be described with reference to FIG. 2, but the present invention is not limited to this.

As shown in FIG. 2, a draft tube 11, an impeller 12, and a static mixer 13 are installed in a reaction container 1 equipped with a heating and heat insulation device. A mixture of raw material fats and oils 5 heated to a predetermined temperature and a chemical catalyst (for example, caustic potash) 6 is stored in the reaction vessel 1. Alcohol 7, which is in the state of superheated steam heated to a predetermined temperature by the heating device 2a, is blown into the mixture of raw material fats and chemical catalyst at a predetermined temperature stored from the nozzle 3, and an excess amount is introduced from the top of the reaction vessel. The reaction product (fatty acid ester and glycerin) 8 is extracted together with alcohol 7 in the form of superheated steam. The mixture of the raw material fats and oils containing alcohol bubbles in the superheated steam state and the chemical catalyst descends the inside of the draft tube by the impeller and forms a circulating flow that rises outside the draft tube. As the circulating flow of the mixture passes through the static mixer, the gas-liquid contact is promoted, and the reaction between the alcohol and the raw material fats and oils is promoted.

[0048] The amount of the chemical catalyst, the temperature of the raw oils and fats, and the temperature of the alcohol in the superheated steam state are the same as in the first embodiment. The tip of the nozzle should be shaped with a perforated plate if necessary (eg lb).

[0049] The static mixer may be an ordinary one used in a chemical apparatus, for example, an appropriate type of sulza, or more simply a plurality of perforated plates laminated at appropriate intervals.

[0050] According to the preferred embodiment described above, the continuous or sequential supply of the raw oils and fats during the transesterification reaction can be omitted unless there is a particular inconvenience. Are also included in the production method of the present invention.

[0051] A mixture of a reaction product containing a fatty acid ester and glycerin and a superheated steam of alcohol in a gas phase or a mixed phase with a droplet phase extracted from the reaction system is a normal mixture. It can be separated and recovered by the method. That is, by cooling the mixture to a temperature at which the alcohol is not liquid! /, Only the alcohol is distilled off in the gas phase. On the other hand, the liquid mixture of fatty acid ester and glycerin can be phase-separated by a method such as standing or centrifuging.

[0052] At this time, the temperature exceeds the boiling point of alcohol (for example, methanol has a boiling point of 65 ° C) and is below the boiling point of fatty acid ester glycerin (290 ° C), preferably about 150 ° C ± 50 ° C. It is preferable to control. As a result, the alcohol in the mixture is mainly in a gas phase, and the fatty acid ester and glycerin are condensed into a liquid phase, so that the gas phase alcohol can be easily separated. The liquid phase fatty acid ester and glycerin can be recovered by phase separation by the above method.

[0053] Further, when there is a certain difference in the boiling points of the fatty acid ester and glycerin, the following method can also be adopted, that is, the above mixture extracted from the reaction system is once compared with the boiling point of glycerin. By controlling the temperature between the boiling points of the fatty acid esters, the condensate A mainly containing the compound having the higher boiling point can be separated. Thereafter, by controlling the temperature of the remaining gas phase mixture below the boiling point of the low boiling point compound and above the boiling point of methanol, the condensate B mainly containing the compound having the lower boiling point can be separated. The remaining gas phase is a gas mainly containing alcohol. Each of the condensates A and B can be further purified as necessary to obtain a desired product.

[0054] The separated vapor-phase alcohol can be heated again to become superheated alcohol and used for the next reaction.

[0055] In the production method of the present invention, by adopting the method as described above, there are the following IJ points.

[0056] That is, the reaction in which fats and oils are brought into contact with each other and transesterified to produce a fatty acid ester and glycerin is generally an equilibrium reaction. Therefore, in a conventional batch method or the like, fatty acid ester and glycerin are used. There is a limit to the amount of product. On the other hand, in the present invention Because the fatty acid ester and glycerin, which are reaction products, are continuously extracted from the reaction system, the fatty acid ester and glycerin are efficiently produced without reaching the equilibrium state.

[0057] In addition, the reaction product obtained is extracted in the gas phase from the reaction system together with the vapor phase flow of alcohol in the form of superheated steam, so that it contains little or no catalyst. . For this reason, it is possible to obtain glycerol and fatty acid esters of high purity necessary for removing the catalyst from the reaction product or the separated fatty acid ester and glycerol.

[0058] Furthermore, since the chemical catalyst remains in the reaction system, it is possible to operate without additional supply of the chemical catalyst over a long period of time.

[0059] In general, the boiling point of alcohol and the boiling point of fatty acid ester or glycerin are greatly different, so that the reaction product and superheated steam in a gas phase extracted from the reaction system or a mixed phase with a droplet-like phase are extracted. The mixture of alcohols in this state can easily separate the alcohol in the gas phase with a relatively small cooling by utilizing the difference in boiling point between the reaction product and the alcohol. Furthermore, the alcohol can be converted into superheated alcohol only by heating and used for the next reaction.

Example

[0060] The ICP analysis and gas chromatograph analysis evaluated in the examples were performed under the following conditions.

[0061] ICP analysis: Perkin Elma ICP emission spectrometer OPTIMA300DV, detection limit 1

/

Gas chromatographic analysis:

Body: GC-380 made by GL Sciences

Column: J & W DB—1, length 30m, inner diameter 0.32mm, film thickness 0.25m

Carrier gas: Helium 90KPa

Column temperature chamber: 50 ° C for 1 minute, temperature raised to 100 ° C at 30 ° CZ, temperature raised to 325 ° C at 3 ° CZ for 163 minutes

Detector: FID

Sample injection volume: Normal hexane 10-fold diluted solution 2 μ 1 Example 1

Rapeseed oil (purity 92%) 150 g is stored in a 300 ml SUS316L sample cylinder (inner diameter 46 mm, filled with SUS304 McMahon packing 100 ml), and chemical catalyst (caustic potash, purity 85.5%) 0.075 g (0 kg per rapeseed oil) Corresponding to 0089 mol). These were held in a 270 ° C hot-air circulating thermostat, and an experiment was conducted in which methanol in the form of superheated steam at 270 ° C was blown from the bottom of the sample cylinder at a rate of 50 g / hr under atmospheric pressure. The reaction products (fatty acid ester and glycerin) were taken out together with methanol in the form of superheated steam with excessive upward force and cooled. The obtained reaction product was concentrated on a rotary evaporator under reduced pressure (3 KPa, 70 ° C) to remove excess methanol, and then the upper fatty acid ester and the lower glycerin were separately obtained by standing separation and weighed. From the first hour to the second hour from the start of the experiment, the amounts of fatty acid ester and glycerin collected were 30.6 g and 3. lg, respectively. In the ICP analysis of the reaction product, potassium was also not detected in fatty acid ester and glycerin. In the gas chromatographic analysis of the reaction product, the content of the raw material fat contained in the fatty acid ester was less than 0.1% (relative area).

[0062] Example 2

The same operation as in Example 1 was carried out except that the chemical catalyst was changed from caustic potash to caustic soda (purity 96%) 0.10 g (corresponding to 0.017 mol per kg of rapeseed oil). During the 1-hour period from the first hour to the second hour, the amounts of fatty acid ester and glycerin collected were 31. lg and 3.2 g, respectively. In the ICP analysis of the reaction product, fatty acid esters and glycerin sodium were also not detected. In the gas chromatographic analysis of the reaction product, the content of the raw oil and fat contained in the fatty acid ester was less than 0.1% (relative area) o

[0063] Example 3

The same operation as in Example 1 was carried out except that the amount of the chemical catalyst added was changed to 0.15 g of caustic potash (corresponding to 0.018 mol per kg of rapeseed oil). During the first hour after the start of the experiment, the amount of fatty acid ester and glycerin collected was 51.6 g and 5.3 g, respectively. In the ICP analysis of reaction products, fatty acid esters and glycerin are also strong. Was not detected. In the gas chromatographic analysis of the reaction product, the content of the raw material fat contained in the fatty acid ester was less than 0.1% (relative area).

[0064] Example 4

The same operation as in Example 1 was conducted, except that the amount of addition force of the chemical catalyst was changed to 0.02 g of caustic potash (corresponding to 0.0028 mol per kg of rapeseed oil). During the first hour after the start of the experiment, the amount of fatty acid ester and glycerin collected was 23.4 g and 2.3 g, respectively. In the ICP analysis of the reaction product, neither fatty acid ester nor glycerin strength was detected. In the gas chromatographic analysis of the reaction product, the content of the raw material fat contained in the fatty acid ester was less than 0.1% (relative area).

[0065] Comparative Example 1

The same operation as in Example 1 was carried out except that no chemical catalyst was added. In the 1 hour period from the 1st hour to the 2nd hour from the start of the experiment, the collected amounts of fatty acid ester and glycerin were 7.2 g and 0.7 g, respectively. In the gas chromatographic analysis of the reaction product, the content of the raw material fat contained in the fatty acid ester was less than 0.1% (relative area).

[0066] Comparative Example 2

In a 300 ml three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, 150 g of rapeseed oil (purity 92%) and 30 g of methanol (boiling point 65 ° C) were taken and heated and stirred until it reached 65 ° C. Add the chemical catalyst (caustic potash, purity: 85.5%) 0.075g (equivalent to 0.018 mole per kg of rapeseed oil) and heat to maintain 65 ° C after the internal solution reaches the specified temperature. Stir for 1 hour. The reaction solution was concentrated under reduced pressure (3 KPa, 70 ° C) with a rotary evaporator to remove excess methanol, and then distilled under reduced pressure (1.3 Kpa, 250 ° C). 1. 8 g of distillate (fatty acid ester and glycerin) was obtained.

[0067] Example 5

The equipment shown in Fig. 1 was used. The apparatus is a stainless steel cylindrical container with a diameter of 100 mm and a height of 500 mm, equipped with a propeller type stirring device. A nozzle with a perforated plate (hole diameter: 3 mm, number of holes: 20) was installed at the tip of a stainless steel pipe with an inner diameter of 5 mm at a height of 50 mm from the bottom of the cylindrical container.

[0068] 1500 g of rapeseed oil (purity 92%) was stored in a cylindrical container and caustic potash (purity 85 5%) 0.775 g (corresponding to 0.0095 mol per kg of rapeseed oil) was added. While stirring at 290 ° C, superheated methanol vapor at 290 ° C was blown through the nozzle at a rate of lOOOOg per hour. During the experiment, raw oils and fats were replenished little by little to keep the liquid level at the initial level. Reaction products (fatty acid esters and glycerin) were removed from above with excess superheated steam methanol. The extracted reaction product and methanol mixture was cooled to 150 ° C., and the reaction product (fatty acid ester and glycerin) was selectively condensed. Further, the reaction product was allowed to stand to separate the fatty acid ester and glycerin, and then weighed. The collected amounts of fatty acid ester and glycerin per hour in an almost stable state after 1 hour from the start of the experiment were 1000 to 1100 g and 90 to 110 g, respectively. In the ICP analysis of the product, no potassium was detected in either fatty acid ester or glycerol strength. In the gas chromatographic analysis of the reaction product, the content of the raw oil / fat contained in the fatty acid ester was less than 0.1% (relative area).

[0069] Example 6

The experiment was performed in the same manner as in Example 5 except that the propeller type stirring device was stopped. The amount of fatty acid ester and glycerin collected per hour in the almost stable state after 1 hour from the start of the experiment was 950 to 1100 g and 90 to 100 g, respectively. ICP analysis of the product [Koo! As a result, fatty acid esters and glycerin were also not detected by potassium. According to the gas chromatographic analysis of the reaction product, the content of the raw oil / fat contained in the fatty acid ester is 0.1.

Less than% of the surface area).

[0070] Comparative Example 3

The experiment was performed in the same manner as in Example 5 except that no chemical catalyst was added. After 1 hour from the start of the experiment The amounts of fatty acid ester and glycerin collected per hour in an almost stable state were 200 to 220 g and 20 to 22 g, respectively. In the gas chromatographic analysis of the reaction product, the content of the raw material fat contained in the fatty acid ester was less than 0.1% (relative area).

Industrial applicability

[0071] According to the present invention, a high-purity fatty acid ester and a by-product glycerin are produced at low cost, and the replacement of a fossil diesel fuel with a plant system is promoted.

Claims

The scope of the claims

[1] A method for producing a fatty acid ester from fats and oils and a monohydric alcohol by using a chemical catalyst, wherein excess monohydric alcohol is continuously supplied to the reaction system in the form of superheated steam. The fatty acid ester is separated and recovered by continuously transesterifying the reaction product containing the fatty acid ester with the superheated vapor of the monohydric alcohol in a gas phase or mixed phase with a droplet phase. Ester production method.

[2] The method for producing a fatty acid ester according to claim 1, wherein the chemical catalyst is an alkali metal compound or a compound of Z and an alkaline earth metal.

[3] The method for producing a fatty acid ester according to claim 1 or 2, wherein the chemical catalyst is sodium hydroxide or Z and potassium hydroxide.

[4] The amount of chemical catalyst used is 0.0002 mol per lKg of raw material fat stored in the reaction vessel.

It is -0.2 mol, The manufacturing method of the fatty acid ester in any one of Claims 1-3.

[5] The reaction vessel pressure during the reaction is close to normal pressure, and the alcohol temperature in the superheated steam state is 250.

The method for producing a fatty acid ester according to any one of claims 1 to 4, wherein the reaction is caused to occur at a temperature of ° C to 350 ° C and a temperature of the fats and oils of 250 ° C to 350 ° C.

[6] A method for producing glycerin from fats and oils and monohydric alcohols using a chemical catalyst, wherein excess monohydric alcohol is continuously supplied to the reaction system in the form of superheated steam and the fats and oils. A method for producing glycerin, in which a transesterification reaction is performed, and a reaction product containing glycerin is continuously withdrawn together with superheated steam of monohydric alcohol in a gas phase or a mixed phase with a droplet-like phase, and glycerin is separated and recovered.

[7] A reaction vessel provided with a heating / heat-retaining device, an oil / fat supply port provided in the reaction vessel, a nozzle for supplying alcohol in the form of superheated steam provided below the reaction vessel, the reaction 6. An outlet for extracting a reaction product in a gas phase provided in an upper part of the container or a mixed phase with a droplet-like phase together with superheated steam of monohydric alcohol. An apparatus for transesterification used in the method for producing a fatty acid ester according to claim 6 or the method for producing glycerin according to claim 6.

[8] A reaction vessel equipped with a heating / heat-retaining device, a draft tube, an impeller, a static mixer, a supply port for supplying oils and fats, and superheated steam in the reaction vessel In order to withdraw the reaction product in a gas phase or a mixed phase with a droplet-like phase provided in the upper part of the reaction vessel together with the superheated monohydric alcohol vapor, and a nozzle for supplying alcohol as a state. The mixture of fats and oils containing alcohol bubbles in the form of superheated steam and chemical catalyst descends inside the draft tube by the impeller, and the mixture rises outside the draft tube. 6. The process according to claims 1 to 5, wherein the circulating flow is arranged such that gas-liquid contact is facilitated by passing the mixture through a static mixer! A transesterification apparatus used in the method for producing a fatty acid ester according to claim 1 or the method for producing glycerin according to claim 7.

[9] The transesterification reactor according to claim 7 or 8, further comprising a temperature control device for superheated steam of monohydric alcohol supplied to the reaction vessel and a temperature control device for oil or fat to be supplied to Z or the reaction vessel.

[10] The transesterification apparatus according to any one of [7] to [9], wherein the nozzle for supplying the superheated vapor of the monohydric alcohol is installed so as to discharge the superheated steam downward in the reaction vessel.

[11] The transesterification apparatus according to any one of claims 7 to 10, wherein a perforated plate is provided at the tip of the nozzle.