JPH0912491A - Alcohol production method - Google Patents

Abstract

PURPOSE: To obtain an alcohol having a high quality with a high purity without requiring the post treatment of the product and without an energy loss by blending a fatty acid glyceride to a raw material monovalent fatty acid ester in the catalytic reduction of the monovalent fatty acid ester. CONSTITUTION: This method for producing an alcohol comprises performing a catalytic reduction of a monovalent fatty acid ester containing a fatty acid glyceride (preferably a mono- or a triglyceride) in the presence of a hydrogenation catalyst (preferably a hydrogenation catalyst containing copper such as Cu-Cr). The content of the fatty acid glyceride is prefeably 0.3-5wt.% based on the mixture of the fatty acid glyceride and the fatty acid ester. The catalytic reduction is preferably performed at 30-250 bar hydrogen pressure, and 180-250 deg.C temperature while continuously supplying hydrogen and the mixture of the raw material so as to make (20:1)-(300:1) molar ratio of hydrogen to an acyl group in the mixture of the raw materials. Also, it is preferable to remove impurities in the fatty acid ester or the fatty acid glyceride beforehand.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing an alcohol by subjecting a fatty acid ester containing a fatty acid glyceride to a catalytic reduction reaction in the presence of a hydrogenation catalyst.

[0002]

BACKGROUND OF THE INVENTION Alcohols, especially higher alcohols, generally consist of natural fats and oils,
It is produced by a catalytic reduction reaction using fatty acids and fatty acid esters as raw materials. In such a manufacturing method,
Conventionally, there have been problems in terms of generation of by-products and catalyst life. Generally, the reaction conditions of the catalytic reduction reaction are 250 to 300 hydrogen in the presence of a hydrogenation catalyst.
Since the bar is at a temperature of 200 ° C. or higher, an excessive reaction tends to occur. As a result, by-products are generated,
There is a problem that the quality of alcohol is deteriorated. Further, since the reduction reaction using the fatty acid ester as a raw material is an exothermic reaction, when a reaction tower is used as a reactor, for example, the temperature in the reaction tower becomes higher than the inlet temperature, and the production of by-products is further promoted.

As a method for improving the problem of by-products, there is a method of improving the production of by-products in the catalytic reduction of fatty acid esters by adding an inert component into the circulating gas or the raw material. For example, the method disclosed in German Patent DE-26132626 suppresses the production of hydrocarbons by adding an inert gas in the circulating hydrogen in an amount of 3 to 30% by volume. German Patent DBP-1005497 The method disclosed in Japanese Patent Laid-Open Publication No. 2003-242242 is such that a lower alcohol is added to a fatty acid ester at 25 to 3
The addition of 00 mol% suppresses the production of hydrocarbons. However, these methods are manufactured because there is energy loss due to temperature rise and cooling of inert components such as inert gas and lower alcohol, and a separation step between the product and the additive is required after the reaction is completed. Cost is high and it is not economical.

When a catalytic reduction reaction is continuously carried out in a fixed bed reactor in which a molded catalyst is immobilized in a column and used, it is important to maintain the catalyst life for a long time, and the catalyst life greatly affects the facility capacity and productivity. Is a factor. By maintaining the temperature inside the column at an apparently isothermal temperature, the by-products such as hydrocarbons and ethers contained in the product alcohol at the beginning of the reaction can be suppressed to a low level, but the reaction heat and impurities in the raw materials make it longer. Since the catalyst activity deteriorates during the operation for a certain period of time, it is necessary to increase the reaction temperature in order to maintain the reaction rate. As the reaction temperature is raised, the amount of by-products mentioned above tends to increase. Since the final life of the catalyst is determined by the reaction rate, the amount of impurities and by-products, even when the reaction is carried out by an isothermal reaction, it is apparent that hydrocarbons and ethers produced as by-products due to excessive reaction The quality of product alcohol gradually deteriorates, and it is difficult to obtain high quality alcohol continuously for a long time.

Also in a fluidized bed reactor using a powder catalyst, since the inlet temperature of the hydrogenation reduction reaction is high and the temperature of the inside of the column is further increased by the heat of reaction, many by-products are generated, which causes It is difficult to reduce.

Therefore, British Patent GB-2225028
The method disclosed in Japanese Patent No. 7 is to add 1 to 1.8% by weight of water to a fatty acid ester to restore or maintain the catalytic activity, and the method disclosed in WO-9406738 is The catalyst activity is improved by adding an inert hydrogen carrier to the fatty acid ester. However, these methods are manufactured because of the energy loss associated with the temperature rise and cooling of water, inert hydrogen carriers and other inert components, and the need for a separation step between the product and additives after the reaction is complete. Cost is high and it is not economical.

[0007] Therefore, an object of the present invention is a method for producing an alcohol by a catalytic reduction reaction in the presence of a hydrogenation catalyst from a monovalent fatty acid ester as a raw material, which causes energy loss without post-treatment of the product. Without
An object of the present invention is to provide a method for producing alcohol of extremely high quality and high purity.

[0008]

The inventors of the present invention have made earnest studies, and as a result, in a method for producing an alcohol by catalytic reduction reaction using a fatty acid ester as a raw material in the presence of a hydrogenation catalyst, a monovalent fatty acid ester as a raw material is used. It was found that the above-mentioned problems can be solved by adding fatty acid glyceride to, and the present invention was completed.

That is, the gist of the present invention is: (1) In a method for producing an alcohol by catalytic reduction reaction using a fatty acid ester as a raw material in the presence of a hydrogenation catalyst, a monovalent fatty acid ester as a raw material contains a fatty acid glyceride. (2) The production method according to (1), wherein the content of the fatty acid glyceride is 0.3 to 30% by weight in the mixture of the raw material and the fatty acid glyceride (raw material mixture), 3) The molar ratio (hydrogen molecule: acyl group) of the acyl group in the mixture of hydrogen and the raw material and the fatty acid glyceride (raw material mixture) is 5: 1 to 500: 1.
While continuously supplying hydrogen and the raw material mixture so that
Hydrogen pressure 20 to 300 bar, reaction temperature 130 to 300 ° C
The production method according to (1) or (2) above, wherein the catalytic reduction reaction is carried out at (4), and the production method according to any one of (1) to (3) above, wherein the hydrogenation catalyst is a copper-containing hydrogenation catalyst. It is a thing.

In the production method of the present invention, the monovalent fatty acid ester used as a raw material is not particularly limited, and a known substance usually used as a raw material of alcohol can be used. For example, the alcohol moiety (monohydric alcohol) of the ester has 1 or more carbon atoms, the fatty acid moiety of the ester is linear or branched, saturated or unsaturated, and contains one ester bond in the ester molecule. There are things. Further, alicyclic carboxylic acid ester and aromatic carboxylic acid ester are also included.

The alcohol moiety of the above ester is not particularly limited, and examples thereof include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-ethylhexanol,
Examples thereof include cyclohexanol and benzyl alcohol.

The fatty acid moiety of the above ester is not particularly limited, and examples thereof include formic acid, acetic acid, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, and olein. Acid, oxalic acid, maleic acid, adipic acid,
Examples thereof include sebacic acid, cyclohexanecarboxylic acid, benzoic acid, phthalic acid and the like.

Specific examples of the above fatty acid ester include, for example, methyl caproate, methyl caprylate, methyl caprate, methyl laurate, methyl myristate, methyl palmitate, methyl stearate, ethyl caproate, caprylic acid. Ethyl, ethyl caprate, ethyl laurate, ethyl myristate, ethyl palmitate, ethyl stearate and the like, further, coconut oil, palm oil, palm kernel oil, soybean oil, rapeseed oil, cottonseed oil,
Fatty acid methyl ester, fatty acid ethyl ester derived from olive oil, beef tallow, fish oil and the like are also included. These monovalent fatty acid esters may be used alone or in combination of two or more.

The fatty acid glyceride contained in the raw material is not particularly limited. For example, fatty acid triglyceride, palm oil, palm oil, palm kernel oil,
Soybean oil, rapeseed oil, cottonseed oil, olive oil, beef tallow, fish oil and the like, and fatty acid diglyceride and fatty acid monoglyceride produced from these fatty acid triglycerides can be mentioned. These fatty acid glycerides may be used alone or in combination of two or more. As the fatty acid glyceride, the effect of the present invention can be obtained with any of mono-, di-, and triglycerides, but monoglyceride or triglyceride is preferable because it is easily available.

The fatty acid glyceride may be present in a predetermined amount during the catalytic reduction reaction, and the form of addition of the fatty acid glyceride is not limited. For example, a predetermined amount of fatty acid glyceride can be contained by adding fatty acid glyceride to the fatty acid ester before the catalytic reduction reaction. When a fatty acid ester synthesized using fatty acid glyceride as a starting material is used, the amount of fatty acid glyceride can be adjusted to a predetermined value by controlling the reaction process or adjusting the purification process.

The hydrogenation catalyst used in the present invention may be a known one generally used for hydrogenation and is not particularly limited. For example, a catalyst containing copper, rhenium, cobalt, or a noble metal as a main component can be used. Of these,
A copper-containing hydrogenation catalyst is preferable from the viewpoint of selective hydrogenation of alcohol. Specific examples of the copper-containing hydrogenation catalyst include C
u-Cr, Cu-Zn, Cu-Si, Cu-Fe-A
1, Cu-Zn-Ti and the like. The form is not particularly limited, and may be appropriately selected from powder, granules, tablets and the like depending on the type of reactor.

Next, the production method of the present invention will be specifically described. In the present invention, alcohol is produced by a catalytic reduction reaction. The reactor used in the production method of the present invention is not particularly limited as long as it can carry out a catalytic reduction reaction, and a commonly used known reactor may be used. For example, a fluidized bed reactor for fluidizing a catalyst with a fluid to perform a catalytic reduction reaction, a moving bed reactor for performing a catalytic reduction reaction by supplying a fluid while the entire catalyst layer gradually falls due to gravity, and a catalyst. A fixed bed reactor or the like that performs a catalytic reduction reaction by filling and fixing and supplying a fluid can be mentioned.

The degree of inclusion of the fatty acid glyceride in the raw material fatty acid ester is not particularly limited as long as the desired effect is obtained, but the content of the fatty acid glyceride is 0.3 to 30% by weight in the raw material mixture. %, More preferably 0.3 to 10% by weight, and particularly preferably 0.3 to 5% by weight. From the viewpoint of suppressing the production of by-products, the content of the fatty acid glyceride is preferably 0.3% by weight or more in the raw material mixture, and from the viewpoint of suppressing the production of ether by-products, it is preferably 30% by weight or less.

The amount of hydrogen supplied in the catalytic reduction reaction is not particularly limited, and the desired effect can be achieved as long as it is a commonly known amount. Further, the hydrogen pressure at this time is not particularly limited, and the desired effect can be achieved as long as it is a commonly known degree. Furthermore, the reaction temperature at this time is not particularly limited,
A desired effect can be achieved by a known degree which is usually performed. However, as the hydrogen supply amount, the molar ratio of hydrogen and the acyl group in the raw material mixture (hydrogen molecule: acyl group) is 5: 1 to 500: 1, and the hydrogen pressure is 20 to 300 bar.
It is preferable that the reaction temperature is 130 to 300 ° C. and the hydrogen and the raw material mixture are continuously supplied to the reactor to carry out the catalytic reduction reaction.

As for the amount of hydrogen supplied, the above molar ratio is more preferably 10: 1 to 400: 1,
It is particularly preferable that the ratio is 20: 1 to 300: 1. The hydrogen pressure is more preferably 25 to 280 bar, particularly preferably 30 to 250 bar.
The reaction temperature is more preferably 160 to 270 ° C, and particularly preferably 180 to 250 ° C. Here, the molar ratio is preferably 5: 1 or more from the viewpoint of maintaining the reaction rate, and is preferably 500: 1 or less from the viewpoint of suppressing an increase in cost due to an increase in equipment due to an increase in the amount of hydrogen gas. The hydrogen pressure is preferably 20 bar or more from the viewpoint of maintaining the reaction rate to alcohol, and is preferably 300 bar or less from the viewpoint of suppressing the cost increase of equipment due to high pressure. Further, the reaction temperature is preferably 130 ° C. or higher from the viewpoint of maintaining the reaction rate, and 30 from the viewpoint of improving the alcohol selectivity of the reaction.
It is preferably 0 ° C or lower.

The alcohol obtained by the production method of the present invention is of good quality with little formation of hydrocarbons and ethers.

When the above fatty acid ester or fatty acid glyceride is used, if the impurities are removed before the catalytic reduction reaction, the catalytic activity is prevented from lowering during the reaction. Especially, when a fixed bed reactor is used for the catalytic reduction reaction. , The active life of the catalyst is dramatically extended. Therefore, it is a further preferred embodiment to use the step of removing impurities as the step before the catalytic reduction reaction. As a method for removing impurities, for example, there is a method using a guard reactor. This method is a method of removing impurities by a chemical reaction using a catalyst. A copper-based or nickel-based catalyst is used as the catalyst. Any reactor may be used as the reactor, and examples thereof include a fluidized bed reactor, a moving bed reactor and a fixed bed reactor. Most impurities contained in fatty acid esters and fatty acid glycerides, typified by sulfur, can be removed by performing a deimpurity treatment through a guard reactor. In addition, other methods for removing impurities include desulfurization by distillation, extraction, etc.
Examples thereof include denitrification, dephosphorization, and dehalogenation treatment. These methods may be performed alone or in combination.

[0023]

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

Example 1 A reaction tower having an inner diameter of 25 mmφ and a height of 2 m was filled with a Cu—Cr catalyst (N202D manufactured by JGC Chemical Co., Ltd.) for reduction activation.
Then, palm kernel oil fatty acid methyl containing 0.3% by weight of lauric acid monoglyceride was passed under hydrogen flow of 60 mol times with respect to the acyl groups in the raw material mixture at 230 ° C. and 200 b.
Ar and hydrogen were obtained under the conditions of a liquid hourly space velocity of the raw material mixture of 1.0 (hour ^-1 ) to obtain alcohol. Table 1 shows the analysis results of the raw material mixture and the reaction product used here.

In this example and the following examples, the saponification value, acid value and hydroxyl value were measured as follows. Saponification value: The amount of potassium hydroxide (mg) required to saponify 1 g of raw material as measured by JIS K0070
Indicated by Acid value: Measured according to JIS K0070, raw material 1
The amount (mg) of potassium hydroxide required to neutralize the fatty acid in g was shown. Hydroxyl value: Measured according to JIS K0070, and shown as the amount (mg) of potassium hydroxide required to neutralize the acetic acid bound when 1 g of the raw material was acetylated.

Hydrocarbons and ethers, which are by-products, were quantified by analyzing the sample by capillary gas chromatography.

Example 2 The content of lauric acid monoglyceride in the raw material mixture was adjusted to 4.
Alcohol was obtained in the same manner as in Example 1 except that the amount was 3% by weight. Table 1 shows the analysis results of the raw material mixture and the reaction product.
Shown in

Example 3 The content of lauric acid monoglyceride in the raw material mixture was set to 9.
Alcohol was obtained in the same manner as in Example 1 except that the amount was 2% by weight. Table 1 shows the analysis results of the raw material mixture and the reaction product.
Shown in

Example 4 The content of lauric acid monoglyceride in the raw material mixture was adjusted to 0.
Alcohol was obtained in the same manner as in Example 1 except that the amount was 1% by weight. Table 1 shows the analysis results of the raw material mixture and the reaction product.
Shown in

Example 5 The content of lauric acid monoglyceride in the raw material mixture was set to 52.
Alcohol was obtained in the same manner as in Example 1 except that the content was changed to wt%. Table 1 shows the analysis results of the raw material mixture and the reaction product.

Example 6 In Example 1, the content of palm kernel oil fatty acid triglyceride was changed to 0.8 instead of lauric acid monoglyceride.
Alcohol was obtained in the same manner as in Example 1 except that the alcohol was used in a weight percentage. Table 1 shows the analysis results of the raw material mixture and the reaction product.

Comparative Example 1 Alcohol was obtained by carrying out the same treatment as in Example 1 without containing any fatty acid glyceride in the raw material mixture. Table 1 shows the analysis results of the raw material mixture and the reaction product.

[0033]

[Table 1]

From Table 1, the following was found. All of the alcohols obtained by the production method of the present invention had good quality with a small amount of by-produced hydrocarbons and ethers (Examples 1 to 6). In particular, Examples 1 to 3 and 6 in which the content of fatty acid glyceride is in the range of 0.3 to 30% by weight.
The alcohol obtained in 1. was of particularly high quality. On the other hand, when a raw material containing no fatty acid glyceride was used, a large amount of by-products were produced (Comparative Example 1).

[0035]

According to the production method of the present invention, it is possible to produce a high-quality and high-purity alcohol with a small amount of by-produced hydrocarbons and ethers. Further, since the fatty acid glyceride to be contained also becomes an alcohol, it is possible to omit a post-process for removing by-products and compounds to be contained.

Claims (4)

[Claims] 1. A method for producing an alcohol by a catalytic reduction reaction using a fatty acid ester as a raw material in the presence of a hydrogenation catalyst, wherein the monovalent fatty acid ester as a raw material contains a fatty acid glyceride. . 2. The content of fatty acid glyceride in the mixture of raw material and fatty acid glyceride (raw material mixture) is 0.3 to
The manufacturing method according to claim 1, which is 30% by weight. 3. Hydrogen and a raw material mixture such that the molar ratio (hydrogen molecule: acyl group) of hydrogen and the acyl group in the mixture of the raw material and the fatty acid glyceride (raw material mixture) is 5: 1 to 500: 1. Hydrogen pressure of 20-30 while continuously supplying
The production method according to claim 1 or 2, wherein the catalytic reduction reaction is carried out at 0 bar and a reaction temperature of 130 to 300 ° C. 4. The production method according to claim 1, wherein the hydrogenation catalyst is a copper-containing hydrogenation catalyst.