JP4330765B2 - Heterogeneous catalyst for esterification reaction - Google Patents

Description

【００３７】
実施例７（触媒調製）
硝酸アルミニウム(0.3mol)とオルトリン酸(0.3mol)の水溶液に、40℃で、ｐＨが７になるまでアンモニア水を滴下することにより得た沈殿を、110℃で乾燥し、粉砕した。この粉砕物に対して、アルミナゾルを10％添加し、1.5mmφの押し出し成形を行った後、400℃で３時間焼成して、成形触媒Ｅを得た。
【００３８】
成形触媒Ｅは細孔直径６〜100nmの細孔容量が0.51ml／ｇであり、酸量が0.79mmol／ｇであった。
【００３９】
実施例８（エステル化反応）
成形触媒Ｅを反応塔に充填し、ラウリン酸とミリスチン酸の混合物（酸価270KOH-mg／ｇ）とメタノールとの固定床連続反応を行った。反応条件は、温度200℃、系内圧力1.0MPa、メタノール／脂肪酸モル比５／１［mol／mol］、ＬＨＳＶ 0.5［１／hr］とした。
【００４０】
反応塔から出た液を水洗し、メタノール及び水を除去することにより、97.1％の収率で脂肪酸メチルエステルを得た。
【００４１】
実施例９（エステル化反応）
成形触媒Ｅを反応塔に充填し、ラウリン酸とミリスチン酸の混合物（酸価270KOH-mg／ｇ）とメタノールとの固定床連続反応を行った。反応は、まず温度200℃、系内圧力1.0MPa、メタノール／脂肪酸モル比３／１［mol／mol］、ＬＨＳＶ ２［１／hr］の条件下で行い、反応塔から出た液からメタノール及び水を留去することにより、88.1％の収率で、脂肪酸メチルエステルを得、続いて、得られた粗脂肪酸メチルエステルを、温度200℃、系内圧力1.0MPa、メタノール／（脂肪酸及び脂肪酸メチルエステル）のモル比３／１［mol／mol］、ＬＨＳＶ ２［１／hr］の条件下反応させた。反応塔から出た液からメタノール及び水を留去することにより、99.7％の収率で脂肪酸メチルエステルを得た。
【００４２】
【発明の効果】
本発明によれば、原料脂肪酸、原料アルコール及び生成したエステルへ触媒成分の溶出が起きない不均一系触媒を用いることにより、生成物と触媒の分離を容易に行いながら、脂肪酸とアルコールから高品質のエステルを高収率で製造することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heterogeneous catalyst for esterification reaction and a method for producing a fatty acid ester using the same.
[0002]
[Prior art and problems to be solved by the invention]
When an esterification reaction is carried out from a fatty acid and an alcohol, a homogeneous catalyst such as sulfuric acid, alkali metal hydroxide, alkaline earth metal oxide, tin oxide, tetraisopropoxytitanium or the like is used.
[0003]
On the other hand, heterogeneous catalysts have been studied from the viewpoint of separation of catalyst components after the reaction. For example, aluminum orthophosphate is used in an esterification reaction between a lower carboxylic acid such as acetic acid and an alcohol such as amyl alcohol (Bull. Soc. Chim. Belg., Vol. 97 (1), p. 17). However, the esterification activity was not satisfactory.
[0004]
An object of the present invention is to provide a heterogeneous catalyst for esterification reaction having high activity.
[0005]
[Means for Solving the Problems]
The present invention is an heterogeneous esterification reaction containing aluminum orthophosphate, having a pore diameter of 6 to 100 nm and a pore volume of 0.46 ml / g or more and an acid amount of 0.40 mmol / g or more. In this method, a fatty acid ester is produced by reacting a raw fatty acid and a raw alcohol in the presence of the system catalyst and the heterogeneous catalyst.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
The method for preparing the catalyst of the present invention is preferably a precipitation method. Specifically, precipitation is obtained by dropping an alkali such as ammonia water dropwise into an aqueous solution in which water-soluble aluminum salt, for example, nitrate, chloride, sulfate, and orthophosphoric acid are mixed. In order to obtain the catalyst of this invention, it is preferable to make the final pH by alkali dripping into 4-10, and it is more preferable to set it as 5-9. Furthermore, it is preferable to keep the liquid temperature for precipitation formation low. Specifically, it is preferably 50 ° C. or lower, and more preferably 30 ° C. or lower.
[0007]
The catalyst of the present invention can be obtained by subjecting the resulting precipitate to treatments such as filtration, washing with water, drying and firing. Firing is preferably performed at a temperature of 150 ° C. or more for 0.1 hour or more from the viewpoint of improving catalyst activity, but calcination at a high temperature exceeding 1000 ° C. reduces the pore volume and the amount of acid. Is preferred.
[0008]
The composition of the catalyst is preferably such that the atomic ratio of aluminum atoms to phosphorus atoms is in the range of 1: 3 to 1: 0.1, and in terms of catalyst activity, the range of 1: 1.2 to 1: 0.2 is particularly preferable.
[0009]
In consideration of diffusion of reaction substrate molecules (raw fatty acid and raw alcohol), the catalyst of the present invention has a pore diameter of 6 than that of micropores having a pore diameter of less than 6 nm, particularly in a liquid phase reaction with a slow diffusion rate. A pore having a diameter of ˜100 nm is more important for the progress of the reaction, and a pore volume having a pore diameter of 6 to 100 nm of 0.46 ml / g or more will exhibit the desired esterification reaction activity. Is preferably 0.5 ml / g or more, more preferably 0.60 ml / g or more. Although there is no restriction | limiting in particular about an upper limit, Actually, it is 1.5 ml / g or less, and 1.0 ml / g or less is easy to implement. Therefore, a desirable specific range is 0.5 to 1.5 ml / g.
[0010]
The catalyst of the present invention has an acid amount of 0.40 mmol / g or more from the viewpoint of esterification reaction activity, preferably 0.5 mmol / g or more, more preferably 0.60 mmol / g or more. Although there is no restriction | limiting in particular about an upper limit, Actually, it is 2.0 mmol / g or less, and 1.6 mmol / g or less is easier to implement. Therefore, a desirable specific range is 0.5 to 2.0 mmol / g.
[0011]
As described above, the present invention has found that the relationship between the pore volume of a specific pore diameter and the acid amount is important for the esterification reaction, and a specific means for realizing it.
[0012]
The form of the catalyst can be used by dispersing it in the raw material as a powder, or it can be used after being molded. A suitable binder may be used during molding. When used as a powder, the catalyst is separated from the reaction solution by filtration after the reaction, but when used as a shaped catalyst, it can be charged into a reaction tower to carry out a continuous reaction.
[0013]
The esterification reaction is performed by reacting a raw fatty acid and a raw alcohol in the presence of the catalyst of the present invention. The raw fatty acid and raw alcohol used are not particularly limited, but as the raw fatty acid, a linear or branched aliphatic carboxylic acid or aromatic carboxylic acid containing 1 to 22 carbon atoms or a mixture thereof, for example, Aliphatic carboxylic acids derived from natural fats and oils such as animal and vegetable oils are used. More specifically, carboxylic acids or dicarboxylic acids such as acetic acid, butyric acid, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, oleic acid and stearic acid can be exemplified.
[0014]
Further, as the raw material alcohol, a monohydric alcohol or a polyhydric alcohol having a straight chain or branched chain containing 1 to 22 carbon atoms is used, and more specifically, methanol, ethanol, propanol, butanol, octanol, stearyl alcohol. And monohydric aliphatic alcohols such as benzyl alcohol, polyhydric alcohols such as ethylene glycol, propylene glycol, glycerin, pentaerythritol, sorbitol, polyethylene glycol, and polypropylene glycol.
[0015]
Examples of the esterification method include a method of continuously supplying the raw fatty acid and the raw alcohol to the reaction tower packed with the catalyst of the present invention, a method of reacting batchwise in a reaction tank, and the like. Further, since water is generated by the progress of the reaction, it is advantageous in terms of shortening the reaction time to separate and remove this continuously or intermittently. As an example of a specific process, a raw material fatty acid and a raw material alcohol are continuously supplied to a fixed bed reaction tower under a liquid phase condition and reacted, and a method described in JP-A-10-81647, or a liquid raw material fatty acid and Examples thereof include a method described in Japanese Patent No. 2706703, in which gaseous raw material alcohol is continuously supplied to a fixed bed reaction tower by gas-liquid countercurrent and / or gas-liquid cocurrent flow and reacted.
[0016]
The catalyst of the present invention has excellent heat resistance and is stable at 400 ° C. or higher. Therefore, there are no particular restrictions on the reaction temperature conditions used. Moreover, since it is insoluble with respect to raw material fatty acid, raw material alcohol, etc., and an elution of an active ingredient does not occur, the reaction can be performed not only in a gas phase system but also in a liquid phase system.
[0017]
【Example】
[Pore volume]
This was measured using a mercury intrusion pore distribution measuring device (pore sizer 9320) manufactured by Shimadzu Corporation.
[Amount of acid]
Using a temperature desorption spectrometer manufactured by Bell Japan, 0.05 g of sample was pretreated at 400 ° C under reduced pressure, adsorbed with ammonia at 50 ° C for 10 minutes, and then subjected to reduced pressure treatment at 50 ° C for 4 hours. After removing the ammonia, the temperature was raised to 600 ° C. at 10 ° C./min, and the ammonia desorption spectrum was measured. The acid amount of the catalyst was determined by comparing this desorption spectrum with the desorption spectrum of the reference catalyst JRC-Z5-25H of the Catalysis Society of Japan whose acid amount is known in advance.
[0018]
Example 1 (catalyst preparation)
A precipitate obtained by adding ammonia water dropwise to an aqueous solution of aluminum nitrate (0.3 mol) and orthophosphoric acid (0.3 mol) at 25 ° C. until a pH of 7 was obtained was calcined at 400 ° C. for 3 hours to obtain catalyst A. Got.
[0019]
Catalyst A had a pore volume of 6 to 100 nm and a pore volume of 0.62 ml / g, and an acid amount of 1.02 mmol / g.
[0020]
Example 2 (Esterification reaction)
Lauric acid (acid value 280 KOH-mg / g) 153.4 g, polyethylene glycol (weight average molecular weight 450) 345 g, catalyst A 12.5 g under normal pressure and nitrogen flow, water distilled out using a dehydration tube While removing, a reaction was carried out at 200 ° C. for 2 hours to obtain a polyethylene glycol laurate having an acid value of 1.1 KOH-mg / g.
[0021]
Example 3 (Esterification reaction)
While adding butanol dropwise to a mixture of stearic acid (acid value 205 KOH-mg / g) 547.0 g and catalyst A 13.7 g under normal pressure and nitrogen flow, and removing distilled water with a dehydrating tube, The reaction was performed at 185 ° C. The dripping amount of butanol was 51 g / hr for 4 hours after the start of the reaction, and then 74 g / hr for 2 hours. The reaction was completed in 6 hours to obtain butyl stearate having an acid value of 0.03 KOH-mg / g.
[0022]
Comparative Example 1 (catalyst preparation)
A precipitate obtained by adding ammonia water dropwise to an aqueous solution of aluminum nitrate (0.3 mol) and orthophosphoric acid (0.3 mol) at 90 ° C. until the pH reached 7 was calcined at 400 ° C. for 3 hours to obtain catalyst B. Got.
[0023]
Catalyst B had a pore volume of 6-100 nm and a pore volume of 0.72 ml / g, and an acid amount of 0.26 mmol / g.
[0024]
Comparative Example 2 (catalyst preparation)
A precipitate obtained by adding ammonia water dropwise to an aqueous solution of aluminum nitrate (0.3 mol) and orthophosphoric acid (0.3 mol) at 25 ° C. until the pH reached 3 was calcined at 400 ° C. for 3 hours to obtain catalyst C. Got.
[0025]
Catalyst C had a pore volume of 6 to 100 nm and a pore volume of 0.44 ml / g, and an acid amount of 1.18 mmol / g.
[0026]
Comparative Example 3 (Esterification reaction)
As a result of carrying out the reaction in the same manner as in Example 2 except that the catalyst B was used in place of the catalyst A, a polyethylene glycol laurate having an acid value of 30.4 KOH-mg / g was obtained.
[0027]
Comparative Example 4 (Esterification reaction)
As a result of carrying out the reaction in the same manner as in Example 2 except that the catalyst C was used instead of the catalyst A, a polyethylene glycol lauric acid ester having an acid value of 21.9 KOH-mg / g was obtained.
[0028]
Comparative Example 5 (Esterification reaction)
As a result of conducting the reaction in the same manner as in Example 2 except that 0.1 g of magnesium oxide was used as the homogeneous catalyst and the reaction temperature was set to 230 ° C., which was advantageous in terms of reaction rate, the acid value was 11.4 KOH-mg. / G polyethylene glycol laurate was obtained.
[0029]
Example 4 (catalyst preparation)
A precipitate obtained by adding ammonia water dropwise to an aqueous solution of aluminum nitrate (0.3 mol) and orthophosphoric acid (0.3 mol) at 40 ° C. until the pH reached 7 was calcined at 400 ° C. for 3 hours to obtain catalyst D. Got.
[0030]
Catalyst D had a pore volume of 6 to 100 nm, a pore volume of 0.49 ml / g, and an acid amount of 0.93 mmol / g.
[0031]
Example 5 (Esterification reaction)
160 g of a mixture of lauric acid and myristic acid (acid value 270 KOH-mg / g), 124 g of methanol and 4 g of catalyst A were reacted at 180 ° C. for 3 hours in an autoclave. The reaction rate by the catalyst, excluding the reaction component under no catalyst at this time, was determined by the following formula (calculated by primary reaction with respect to the acid value). The results are shown in Table 1.
[0032]
Catalytic reaction rate [1 / hr] =
(1/3) × ln {(AV _0h −AV _e ) / (AV _3h −AV _e )} − (1/3) × ln {(AVN _0h −AV _e ) / (AVN _3h -AV _e )}
Here, AV _0h is the acid value (KOH-mg / g) of the reaction solution at 0 hour in the reaction in the presence of a catalyst, and AV _3h is the acid value of the reaction solution at 3 hours in the reaction in the presence of the catalyst ( KOH-mg / g), AV _e is the acid value at the reaction equilibrium (KOH-mg / g), AVN _0h is the acid value of the reaction solution at 0 hours in the non-catalytic reaction (KOH-mg / g), AVN _3h Is the acid value (KOH-mg / g) of the reaction solution at 3 hours in the non-catalytic reaction.
[0033]
Example 6 (Esterification reaction)
The reaction was performed in the same manner as in Example 5 except that the catalyst D was used instead of the catalyst A, and the reaction rate was determined in the same manner. The results are shown in Table 1.
[0034]
Comparative Example 6 (Esterification reaction)
The reaction was performed in the same manner as in Example 5 except that catalyst B was used instead of catalyst A, and the reaction rate was determined in the same manner. The results are shown in Table 1.
[0035]
Comparative Example 7 (Esterification reaction)
The reaction was performed in the same manner as in Example 5 except that the catalyst C was used instead of the catalyst A, and the reaction rate was determined in the same manner. The results are shown in Table 1.
[0036]
[Table 1]

[0037]
Example 7 (catalyst preparation)
A precipitate obtained by adding ammonia water dropwise to an aqueous solution of aluminum nitrate (0.3 mol) and orthophosphoric acid (0.3 mol) at 40 ° C. until the pH reached 7 was dried at 110 ° C. and pulverized. 10% alumina sol was added to the pulverized product, and extrusion molding with 1.5 mmφ was performed, followed by firing at 400 ° C. for 3 hours to obtain a molding catalyst E.
[0038]
Molded catalyst E had a pore volume of 6 to 100 nm, a pore volume of 0.51 ml / g, and an acid amount of 0.79 mmol / g.
[0039]
Example 8 (Esterification reaction)
The forming catalyst E was packed in a reaction tower, and a fixed bed continuous reaction between a mixture of lauric acid and myristic acid (acid value 270 KOH-mg / g) and methanol was performed. The reaction conditions were a temperature of 200 ° C., an internal pressure of 1.0 MPa, a methanol / fatty acid molar ratio of 5/1 [mol / mol], and LHSV of 0.5 [1 / hr].
[0040]
The liquid coming out of the reaction tower was washed with water, and methanol and water were removed to obtain a fatty acid methyl ester in a yield of 97.1%.
[0041]
Example 9 (esterification reaction)
The forming catalyst E was packed in a reaction tower, and a fixed bed continuous reaction between a mixture of lauric acid and myristic acid (acid value 270 KOH-mg / g) and methanol was performed. The reaction is first carried out under the conditions of a temperature of 200 ° C., an internal pressure of 1.0 MPa, a methanol / fatty acid molar ratio of 3/1 [mol / mol], and LHSV 2 [1 / hr]. By distilling off water, fatty acid methyl ester was obtained in a yield of 88.1%, and then the obtained crude fatty acid methyl ester was heated at a temperature of 200 ° C., an internal pressure of 1.0 MPa, methanol / (fatty acid and fatty acid methyl ester). The reaction was performed under the conditions of an ester) molar ratio of 3/1 [mol / mol] and LHSV 2 [1 / hr]. By distilling off methanol and water from the liquid coming out of the reaction tower, fatty acid methyl ester was obtained in a yield of 99.7%.
[0042]
【The invention's effect】
According to the present invention, by using a heterogeneous catalyst in which elution of the catalyst component does not occur in the raw fatty acid, the raw alcohol and the generated ester, the product and the catalyst can be easily separated from each other, and the high quality from the fatty acid and the alcohol. Can be produced in high yield.

Claims (6)

A heterogeneous catalyst for an esterification reaction containing aluminum orthophosphate, having a pore diameter of 6 to 100 nm, a pore volume of 0.46 ml / g or more, and an acid amount of 0.40 mmol / g or more. The heterogeneous catalyst for esterification reaction according to claim 1, wherein the pore volume having a pore diameter of 6 to 100 nm is 0.5 ml / g or more. The heterogeneous catalyst for esterification reaction according to claim 1 or 2, having an acid amount of 0.5 mmol / g or more. The heterogeneous catalyst for esterification reaction according to any one of claims 1 to 3, wherein the atomic ratio of aluminum atoms to phosphorus atoms in the aluminum orthophosphate is in the range of 1: 3 to 1: 0.1. The manufacturing method of the fatty acid ester which makes a raw material fatty acid and raw material alcohol react with presence of the heterogeneous catalyst in any one of Claims 1-4. 6. The method for producing a fatty acid ester according to claim 5, wherein the raw fatty acid is an aliphatic carboxylic acid derived from natural fats and oils.