JPH02184645A - Production of unsaturated alcohol - Google Patents

Abstract

PURPOSE:To selectively produce the subject alcohol having a high degree of unsaturation by using a fish oil having a high degree of unsaturation and many double bonds as the raw material and carrying out high-pressure hydrogenation thereof in the presence of a specified Zn-Cr-based catalyst under specified conditions using a fixed bed-type reactor. CONSTITUTION:A fish oil having a high degree of unsaturation and many double bonds or an ester thereof is subjected to high-pressure hydrogenation in the presence of a Zn-Cr-based catalyst having 1.75-3.20 Zn/Cr atomic ratio and reduced at 270-450 deg.C at 285-320 deg.C under 170-250kg/cm<2>G and 1.2-3.0Nm<3>/1 ratio of H2/raw material using a fixed bed-type reactor, thus producing the objective compound. In addition, the lowering ratio of iodine value is <=15% and impurities such as dimer or trimer are not produced. A separation process after the reaction can be omitted and the equipment is simplified. The reaction pressure and hydrogen supply can be reduced and a remarkable improvement is possible in respect of safety and reduction of the equipment cost and the manufacturing cost.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for hydrogenolyzing fish oil or its ester,
The present invention relates to a method for selectively producing a highly unsaturated alcohol that retains most of the double bonds in the raw material.

[Prior Art] Various methods for producing unsaturated alcohols using oils with a high degree of unsaturation as raw materials have been proposed, and the main ones will be explained below.

The conventional method used is to reduce fatty acid esters to alcohol using metallic Na, and this method allows the production of the desired alcohol without reducing the degree of unsaturation at all. It has drawbacks such as being extremely expensive, using a large amount of metallic Na, and being highly dangerous.

Therefore, attempts have been made to produce unsaturated alcohols by hydrogen reduction using suitable catalysts, and Japanese Patent Publication No. 40-27730 discloses that fats and oils containing unsaturated fatty acids, liquid waxes, and esters of lower alcohols have been produced by hydrogen reduction using suitable catalysts. When performing pressurized reduction using zinc-aluminum and zinc-chromium catalysts, the hydrogen pressure at the reaction temperature is set at 300 to 5
A method for producing unsaturated alcohol under pressure of 0.00 atm has been proposed.

However, according to the examples, when highly unsaturated fatty acids with an iodine value of about 100 or more are used as raw materials, the reduction rate of the iodine value, which indicates the degree of unsaturation, is all 20% or more, which is not necessarily a satisfactory method. do not have.

Furthermore, Japanese Patent Publication No. 45-2562 discloses that a catalyst which has been subjected to a high temperature treatment at 500 to 900°C in the form of an oxygen-containing compound in a reducing atmosphere is used at a temperature of 250 to 330°C; High temperature heating in the presence of a bulk zinc-chromium or zinc-aluminum catalyst, characterized in that the hydrogenation is carried out at a pressure of 500 atm and with an amount of hydrogen of 10 to 1100 N' per 12 of the feedstock to be hydrogenated. A process has been proposed for the preparation of unsaturated aliphatic alcohols by continuous hydrogenation of unsaturated fatty acids with 8 to 22 carbon atoms or their esters with monohydric aliphatic alcohols under pressure in excess of hydrogen.

According to the same specification, this process is said to be significantly superior to zinc-chromium catalysts made by low-temperature reduction at 280-350°C, which previously showed the greatest selectivity in terms of double bond retention. Although the examples show that the rate of decrease in iodine value is small, the required amount of hydrogen is 10 to 1100 N per 12 raw materials! There are significantly more.

-Fish oil, which is the subject of the Rikiki invention, generally has an iodine value of 1
00 or more highly unsaturated fatty acids, especially with 4 to 6 double bonds
They are different from other fats and oils in that they are
Occasionally, thermal decomposition/polymerization reactions occur, the iodine value of the resulting oil decreases, and dimers or trimers are formed due to carbon-carbon bonds.

The above-mentioned prior art shows examples in which oils and fats having 1 to 2 to 3 double bonds are treated, but
Examples for individual fish oils are not shown.

The present inventors traced the above-mentioned prior art using fish oil as a raw material, but in many cases the iodine value decreased significantly and dimers etc. were confirmed in the produced oil.

When impurities such as di- and trimers increase, the load on the subsequent purification process increases.

[Problems to be Solved by the Invention] The present invention is directed to producing highly unsaturated alcohols by high-pressure hydrogenation of highly unsaturated fish oils or esters thereof. 10
% or less and does not generate impurities such as dimers and trimers.

When such raw materials are used, if the catalyst activity and reaction conditions are mild, double bonds are preserved and the iodine value decreases little, but the conversion rate to alcohol decreases. That is, the saponification value decrease rate is small.

On the contrary, if the activity of the catalyst is high and the reaction conditions are severe, the conversion rate to alcohol will increase and the saponification value will decrease at a high rate, but the double bonds will also be hydrogenated and the iodine value will decrease.

Therefore, hydrogenation of fish oil requires extremely delicate selection of conditions. The present invention solves this problem.

[Means for Solving the Problems] The present invention provides a method for producing a highly unsaturated alcohol by high-pressure hydrogenation of fish oil or its ester.
/Cr atomic ratio is in the range of 1.75 to 3.20 and 2
Using a fixed-bed reactor in the presence of a zinc-chromium catalyst that has been reduced at a temperature in the range of 70 to 450°C,
This is a method for producing an unsaturated alcohol, which is characterized by high-pressure hydrogenation under the following reaction conditions.

Reaction temperature = 285-320°C Reaction pressure: 170-250 Kg/cm2GH, /Raw material ratio: 1.2-3. ONm' /42 and below The test results that serve as the basis for the above gender settings will be explained in order.

[Test 1] (Influence of Zn/Cr atomic ratio) Table 1 Z n / Cr atomic ratio 1.50, 1.90, 3.05
Alternatively, using a zinc-chromium oxide catalyst of 3.20, a hydrogenolysis reaction was carried out using sardine oil ethyl ester having the properties shown in Table 1 as a raw material.

Approximately 45 cc of 3 mmφ tablets of each catalyst were packed into a fixed bed type reactor and reduced in a hydrogen stream at 300°C for approximately 4 hours at normal pressure.
Increase the pressure to m'G and reduce the hydrogen/raw material ratio to 2. ONm3/I2,
The reaction was carried out at a reaction temperature of 290°C and a LH8V of 0.15 hr-'.

The test results are shown in Figure 1. In Figure 1, the horizontal axis represents the Z n / Cr atomic ratio of the catalyst, the vertical axis represents the saponification value reduction rate or iodine value reduction rate (%), and the O mark represents the saponification value reduction rate, 0
The marks indicate the iodine number reduction rate, and line A indicates the area of the invention.

Note that the saponification value reduction rate and the iodine value reduction rate are values shown by the following formulas, respectively.

Saponification value reduction rate = Iodine value reduction rate = Iodine value reduction rate is 4 when the Z n / Cr atomic ratio is 1.5
It can be 0%, but at 1.75 it is 15% and at 1.9 it is 10%.
%, and thereafter becomes smaller as the atomic ratio increases.

On the other hand, the saponification value decrease rate is 80% or less when the Z n /Cr atomic ratio is 1.5, but increases to 90% or more when it is around 1.75, maintains a high level until around 3.2, and then decreases.

[Test 2] (Influence of catalyst reduction temperature) Using the zinc-chromium oxide catalyst with a Z n /Cr atomic ratio of 1.90 used in Test 1, the catalyst reduction temperature was set at 200°C.
, 300°C, 500°C, 700°C, or 950°C, but using the same fixed bed type reactor as in Test 1, the reaction was carried out using the same raw materials and under the same conditions.

The test results are shown in Figure 2. In Figure 2, the horizontal axis represents the catalyst reduction temperature (°C), and the vertical axis represents the saponification value reduction rate (%).
The O symbol indicates the saponification value reduction rate, and the line A indicates the area of the present invention.

The saponification value reduction rate is 60% or less at a reduction temperature of 200°C, but increases to 90% or more at around 250°C, peaks at around 400°C, and gradually decreases at higher temperatures.

[Test 3] (Effect of reaction temperature) Table 2 Using sardine oil methyl ester with the properties shown in Table 2 as a raw material,
The zinc-chromium oxide catalyst with a Zn/Cr atomic ratio of 3.05 used in Test 1 was reduced at 290°C in a hydrogen stream at normal pressure for about 5 hours, and the same fixed bed type catalyst as in Test 1 was used. Using a reactor, the reaction temperature was set to 260°C, 275°C, 29
The reaction was carried out under the same conditions as Test 1 except that the temperature was changed to 0"C or 310"C.

The test results are shown in Figure 3. In Figure 3, the horizontal axis is the reaction temperature (°C), and the vertical axis is the saponification value reduction rate or iodine value reduction rate (
%), O mark indicates saponification number reduction rate, 0 mark indicates iodine value reduction rate, and line A indicates the area of the present invention.

The iodine value reduction rate is about 4% at a reaction temperature of 260°C, but at this temperature the saponification value reduction rate is very low at 40%. Even at a reaction temperature of 270°C, the saponification value reduction rate is less than 70%. , it becomes over 90% at around 285°C and remains at a high level thereafter. Note that the iodine value reduction rate exceeds 10% at around the reaction temperature of 285°C, but the increase thereafter is slow.

[Test 4] (Effect of reaction pressure) The zinc-chromium oxide catalyst used in Test 1 with a Zn/Cr atomic ratio of 3.05 was reduced at 290°C in a hydrogen stream at normal pressure for about 5 hours. Using the same fixed bed type reactor as Test 1, the reaction pressure was set to 150.200.2501.
The reaction was carried out using the same raw materials and under the same conditions as in Test 3, except that 290 or 500 K g/cm2G was used.

The test results are shown in Figure 4. In Figure 4, the horizontal axis represents the reaction pressure (K g / cm 2G), the vertical axis represents the saponification value reduction rate or iodine value reduction rate (%), the O mark represents the saponification value reduction rate, and the 0 mark represents the iodine value. Indicates the rate of decrease in value.

Line A also indicates the area of the present invention.

Saponification value reduction rate is 90% at reaction pressure 170Kg/cm2
9 at a reaction pressure of 200 K g/cm2
After it exceeds 5%, it does not increase even if the pressure is increased. On the other hand, the iodine value reduction rate is about 10% until the reaction pressure is around 250 kg/cm'G, but after that it gradually increases.

This shows that it is not only meaningless to increase the reaction pressure above 250 Kg/cm'G, but is even harmful.

[Test 5] (Effect of hydrogen/oil conversion) The zinc-chromium oxide catalyst with a Zn/Cr atomic ratio of 3.05 used in Test 1 was reduced at 290°C in a hydrogen stream at normal pressure for about 5 hours. Using the same fixed bed type reactor as in Test 1, hydrogen/oil conversion was carried out in 1.0.1.6.1.
8.2.0.5.3 or 10, and the reaction was carried out using the same raw materials and under the same conditions as Test 3, except that ONm3/β was changed.

The test results are shown in Figure 5. In Figure 5, the horizontal axis is hydrogen/
Oil conversion (Nm'/β), the vertical axis represents the saponification value reduction rate or iodine value reduction rate (%), the circle mark indicates the saponification value reduction rate, and the 0 mark indicates the iodine value reduction rate. Line A also indicates the area of the present invention.

The saponification value reduction rate is hydrogen/oil conversion 1. 85 for ONm3/β
%, but after exceeding 90% at hydrogen/oil conversion of 1.2 and exceeding 95% at hydrogen/oil conversion of 1.5, it does not increase no matter how much hydrogen/oil conversion is increased.

However, the iodine value reduction rate is 10% until hydrogen/oil conversion around 2.0
However, it will gradually increase thereafter.

This shows that increasing the hydrogen/oil ratio to 3 Nm3/42 or more is not only meaningless, but even harmful.

According to the present invention, unsaturated alcohols can be easily produced from fish oils with a high degree of unsaturation and a large number of double bonds, such as sardine oil, mackerel oil, or cod oil, or esters thereof.

[Example 1] Approximately 45 cc of a 3 mm diameter compressed catalyst having a Z n /Cr atomic ratio of 1.90 was packed into a fixed bed type reactor and reduced at 300° C. for approximately 4 hours at normal pressure in a hydrogen stream. After the reduction was completed, the pressure inside the system was increased to 200 Kg/cm2G) with hydrogen. The raw material is sardine oil ethyl ester, and the hydrogen ratio is 2. ONm'
/β, a reaction temperature of 290° C., and a hydrogenolysis reaction of LH3V of 0.15 hr-'.

The properties of the raw sardine oil ethyl ester and the produced oil are as follows.
It was as shown in the table.

Table 3 About 45 cc of a 3 mm diameter tablet of catalyst having a Zn/Cr atomic ratio of 3.05 was charged into a fixed bed type reactor and reduced at room temperature for about 5 hours at 290° C. in a hydrogen stream. After the reduction was completed, the pressure inside the reactor system was increased to 200 Kg/cm2G using hydrogen. Sardine oil ethyl ester was used as a raw material, and a hydrogenolysis reaction was carried out under the reduction conditions and reaction conditions of Example 1.

The properties of the raw material sardine oil ethyl ester and the produced oil are as follows.
It was as shown in the table.

In Table 4, the hydroxyl value indicates the amount of OH groups (alcohol).

[Example 2] [Comparative Example 1] A fixed bed type reactor was filled with 45 cc of a catalyst having a Z n /Cr atomic ratio of 3.40 and heated at 300° C. in a hydrogen stream under normal pressure.
I was away for about 5 hours. After completion of the reduction, a hydrogenolysis reaction was carried out under the reaction conditions of Example 1.

The properties of the raw material sardine oil ethyl ester and the produced oil are as follows.
It was as shown in the table.

Table 5 [Comparative Example 2] 45 cc of a catalyst with a Z n /Cr atomic ratio of 1.50 was packed into a fixed bed type 8 reactor, and 300 cc of catalyst with a Z n /Cr atomic ratio of 1.50 was charged in a hydrogen stream under normal pressure.
It was incubated at ℃ for about 5 hours. After completion of the reduction, a hydrogenolysis reaction was carried out under the reaction conditions of Example 1.

The properties of the raw material sardine oil ethyl ester and the produced oil are as follows.
It was as shown in the table.

Table 6 [Example 3] Using sardine oil (glyceride) as a raw material, Example 2
A hydrogenolysis reaction was carried out using the following catalyst, reduction conditions, and reaction conditions.

The properties of the raw material oil and the produced oil were as shown in Table 7. Table 7 [Comparative Example 3] The method of the present invention is particularly effective when using a fixed bed type reactor, and the same An example of a case in which satisfactory results cannot be obtained using a suspended bed type reactor even if a catalyst is used will be shown below.

Using the catalyst of Example 1, a hydrogenolysis reaction of sardine oil ethyl ester was carried out using a suspended bed type reactor. The reduction of the catalyst was carried out at 350° C. for about 6 hours under a hydrogen atmosphere. After reduction, the pressure was increased to 200 kg/cm2G using hydrogen, and the temperature was lowered to 29.0°C. After reaching the predetermined temperature and pressure, the mixture was stirred for about 10 hours. During the reaction, whenever the pressure decreased, hydrogen was replenished to a predetermined pressure. The amount of catalyst is 5% of the feedstock oil.
% amount was used.

The properties of the raw material oil and the produced oil were as shown in Table 8.

8th Table temperature. After reaching the predetermined temperature and pressure, the mixture was stirred for about 10 hours. During the reaction, whenever the pressure decreased, hydrogen was replenished to a predetermined pressure. The amount of catalyst used was 5% of the raw oil.

The properties of the raw material oil and produced oil were as shown in Table 9.

Table 9 [Comparative Example 4] Using sardine oil as a raw material and the catalyst of Example 2,
Hydrocracking reaction was carried out using a suspended bed type reactor.

The reduction of the catalyst was carried out at 300° C. for 5 hours under a hydrogen atmosphere. After completion of reduction, increase the pressure to 200Kg/cm2G with hydrogen,
[Comparative Example 5] The method of the present invention is particularly effective in the case of fish oil with a high degree of unsaturation (and a large number of double bonds), and even if the same catalyst and the same conditions are used. Satisfactory results cannot be obtained with oils other than fish oil.An example of such a case is shown below.

Using the catalyst and reaction conditions of Example 1, a hydrocracking reaction was carried out in a fixed bed flow type reactor using palm oil as a raw material.

The properties of the raw material oil and the produced oil were as shown in Table 1O.

Table 10 In palm oil with a low degree of unsaturation, the reaction activity of the catalyst is extremely low.

[Effects of the invention] (1) An unsaturated alcohol can be obtained as a fish oil raw material with a high degree of unsaturation (and a large number of double bonds).

■Compared to conventional high-pressure hydrocracking methods, it can be carried out at relatively lower pressures. Furthermore, compared to conventional high-pressure hydrocracking methods, it can be carried out with extremely small amounts of hydrogen/oil.

Therefore, it is possible to reduce the reaction pressure and hydrogen supply amount,
Significant improvements can be made over conventional methods in terms of safety, reduction in equipment cost, and reduction in manufacturing cost.

(2) Since there is little unreacted fatty acid in the produced oil and there are almost no side reaction products (hydrocarbons, dimers, dimers, etc.), it is possible to omit the separation step after the reaction.

Therefore, the device is simplified, which also greatly contributes to reducing the device cost and manufacturing cost.

[Brief explanation of the drawing]

Figures 1 to 5 all show the influence of the catalyst or operating conditions on the saponification number reduction rate and the iodine value reduction rate. Figure 1 shows the influence of the Zn/Cr atomic ratio of the catalyst, and Figure 2 3 shows the effect of catalyst reduction temperature, FIG. 3 shows the effect of reaction temperature, FIG. 4 shows the effect of reaction pressure, and FIG. 5 shows the effect of hydrogen/oil conversion.

Claims (1)

[Claims] In producing a highly unsaturated alcohol by high-pressure hydrogenation of fish oil or its ester, the Zn/Cr atomic ratio is in the range of 1.75 to 3.20 and the temperature is in the range of 270 to 450°C. A method for producing an unsaturated alcohol, which comprises carrying out high-pressure hydrogenation under the following reaction conditions using a fixed-bed reactor in the presence of a zinc-chromium catalyst that has been subjected to a reduction treatment at a temperature of . Reaction temperature: 285-320℃ Reaction pressure: 170-250Kg/cm^2G H_2/raw material ratio: 1.2-3.0Nm^3/l