KR101336975B1 - Catalyst for manufacturing alkylamine from reductive amination - Google Patents

Abstract

The present invention relates to a catalyst useful for preparing alkylamines by reductive amination reactions of alcohols. More specifically, in the presence of hydrogen, isopropyl alcohol is reacted with ammonia to effectively prepare monoisopropylamine, a primary amine compound at normal pressure, and a cobalt precursor is impregnated into a γ-Al ₂ O ₃ support to give Co ₃ A method for producing an O ₄ / γ-Al ₂ O ₃ catalyst and a method for producing an alkylamine using the catalyst.
The reductive amination catalyst prepared by the above method can maintain the catalytic activity stably at normal pressure for a long time instead of the reductive amination reaction at a high pressure, and requires a reductive amination reaction of alcohols as well as isopropyl alcohol. Is a very economical and efficient catalyst that can be useful in many processes.

Description

Catalyst for producing alkylamine by reductive amination of alcohol {Catalyst for manufacturing alkylamine from reductive amination}

The present invention relates to a Co ₃ O ₄ / alumina catalyst having a Co ₃ O ₄ active ingredient supported on an alumina carrier as a catalyst for producing alkylamine by reductive amination of alcohol.

Alkylamines are important substances as intermediates and raw materials in various fields such as chemistry, pharmaceuticals, agriculture, rubber, solvents and the like. Monoisopropylamine as a compound representing alkylamine is used as a raw material of isopropyl hydroxyamine, which serves to control and stop the chain reaction during the polymerization of the polymer.

As a method for producing alkylamine, a method of reducing amination of alcohol is known. The term 'reductive amination of alcohol' refers to a reaction in which a primary, secondary or tertiary amine product is obtained by reaction with alcohol, ammonia and hydrogen in the presence of a catalyst which is active in the hydrogenation-dehydrogenation reaction.

As a catalyst for reductive amination of alcohols, metals such as nickel, cobalt, or copper may be used alone, or metals (eg, palladium, ruthenium, zinc, magnesium, iron, etc.) serving as enhancers to increase selectivity of alkylamines. Use a small amount of mixture. Typically, reductive amination reactions produce primary amines by the reaction of alcohols with ammonia in the presence of hydrogen. Good selectivity for amines is usually obtained under high pressure reaction conditions in which secondary alcohols are present in the presence of excess ammonia under suitable catalysts. In addition, before carrying out the reaction, the reducing amination catalyst is reacted by reducing at an appropriate temperature, and it is preferable to add hydrogen gas during the reaction to maintain high catalytic activity and selectivity and catalyst stability.

Fischer et al. (A. Fischer et al.) Disclose a method for preparing ethylamines by reductive amination of ethanol under a catalyst in which nickel or cobalt is impregnated on a silica support (Appl. Catal. 125, (1995). 99). According to the paper, catalysts impregnated with cobalt on silica supports are mentioned as more useful for reductive amination reactions than catalysts impregnated with nickel.

U.S. Patent No. 5,917,092 describes a process for producing monoisopropylamine from isopropyl alcohol using a catalyst prepared by ion exchange of cobalt and potassium to NH ₄ -ZSM-5, a type of zeolite. The patent document showed that the K-Co-ZSM-5 catalyst had a conversion rate of 100% and a monoisopropylamine selectivity of 90% or more under a reaction temperature of 212 ° C. and a pressure condition of 17 bar. However, it takes more than 5 days to prepare the catalyst, it is difficult to ion-exchange cobalt and potassium quantitatively according to the Si / Al ratio of NH ₄ -ZSM-5, there was a disadvantage that it is dangerous by reacting under pressure conditions.

U.S. Patent No. 4,912,260 describes a process for converting isopropyl alcohol to monoisopropylamine under autogenous pressure by liquid phase reaction using an autoclave using a nickel-palladium-ruthenium-alumina catalyst prepared by impregnation. This is a liquid phase reaction under autogenous pressure, there is a difficulty in the continuous reaction process, it was difficult to separate the reactant and the catalyst. In addition, since the yield of the desired monoisopropylamine shows a low yield of 12.4 to 62.6% depending on the reaction conditions, the method is economically unfavorable for reductive amination for monoisopropylamine production. .

U.S. Patent No. 5,932,769 describes a method for converting isopropyl alcohol to monoisopropylamine using a catalyst prepared by impregnating cobalt and palladium on an alumina support. The patent document showed that the cobalt-palladium catalyst had a conversion rate of 90% or more and a monoisopropylamine selectivity of 70% or more under a reaction temperature of 193 ° C. and a pressure of 17 bar. However, since the palladium of expensive precious metals is used as a catalyst and the reaction proceeds under high pressure conditions, the method is economically unfavorable for reductive amination for monoisopropylamine production.

The present invention is difficult to proceed to the continuous process by producing a monoalkylamine by the reductive amination reaction of the alcohol in the liquid phase under autogenous pressure, difficult to separate the reactant and the catalyst, the reaction process under high pressure conditions It is an object of the present invention to solve problems such as the progress of the process and the production process of the catalyst applied is complicated.

That is, an object of the present invention is to provide a novel catalyst and a method for producing the same, which can be applied to the reductive amination reaction of alcohol to effectively proceed the reaction even under atmospheric pressure conditions and can stably maintain the catalytic activity for a long time. In addition, an object of the present invention is to provide a method for producing an alkylamine by amination of an alcohol using the catalyst.

In order to achieve the above object, the present invention is characterized by the Co ₃ O ₄ / alumina catalyst used in the reductive amination reaction of alcohol.

In addition, the present invention is Co ₃ O ₄ / alumina for reducing amination reaction of alcohol prepared by supporting the aqueous solution of cobalt precursor on the support using the impregnation method, and then dried and calcined It is characterized by a method for producing a catalyst.

In addition, the present invention is Co ₃ O ₄ / alumina Contacting the catalyst with hydrogen to activate the catalyst, mixing alcohol with ammonia to form an amination reaction mixture, and reacting the amination reaction mixture with the activation catalyst at 0.5 to 2.0 atmospheres in the presence of hydrogen. It is characterized by a method for producing an alkylamine comprising the step.

Co ₃ O ₄ / alumina of the present invention Since the catalyst is applied to the reductive amination reaction of alcohol, it maintains high catalytic activity stably for a long time even under normal pressure (pressure of about 1.0 atm), thereby improving the conventional method of maintaining high pressure reaction conditions.

Thus Co ₃ O ₄ / alumina Catalysts are very economical and efficient catalysts that can be usefully used in many processes that require alcohol amination reactions.

1 is a Co ₃ O ₄ / γ-Al ₂ O ₃ (Example 4) catalyst and Co / γ-Al ₂ O ₃ Each catalyst is an X-ray diffraction pattern.
2 is Co ₃ O ₄ / γ-Al ₂ O ₃ (Example 4) TGA-DTA analysis of the catalyst.
3 is Co ₃ O ₄ / γ-Al ₂ O ₃ (Comparative Example 1) TGA-DTA analysis of the catalyst.

The present invention is a Co ₃ O ₄ / alumina used in the reductive amination reaction of alcohol It relates to a catalyst.

Alumina (Al ₂ O ₃ ) used in the preparation of Co ₃ O ₄ / alumina catalyst of the present invention is generally used as a support in the field of catalyst production, it may include α-alumina, γ-alumina and the like. γ-Al ₂ O ₃ is a metal oxide having a specific surface area of about 150 to 300 m ² / g. The γ-Al ₂ O ₃ is prepared in a gamma phase by calcining an alumina gel at about 600 ° C. Such γ-Al ₂ O ₃ is porous and has high thermal stability, high purity, and has the advantage of having a special physical property by controlling synthetic conditions.

As the active ingredient supported on the alumina support, cobalt is preferably supported in the range of 4 to 30% by weight based on the total weight of the catalyst. If the supported amount of cobalt is less than 4% by weight, the content of the active ingredient may be too small, so that the effect of the catalyst may be insignificant when applied to the reductive amination of alcohol, and the excess amount may be more than 30% by weight. There is a problem that the active ingredient is not evenly dispersed on the support.

As described above, the catalyst of the present invention is a cobalt oxide catalyst in which cobalt oxide (Co ₃ O ₄ ) is supported on an alumina support, and the supported form of the cobalt component may vary depending on the preparation method of the catalyst. That is, the cobalt component may be supported in the form of cobalt metal (Co) and cobalt oxide (CoO, Co ₂ O ₃ , Co ₃ O ₄ ) according to the supporting conditions of the cobalt precursor for the support. The cobalt catalyst for reducing amination reaction of alcohol reported to date is a Co / alumina catalyst in which a cobalt metal is supported on an alumina support, and is prepared by drying the catalyst slurry at a temperature of 100 ° C. or higher and then firing it at 400 ° C. to 600 ° C. . However, in the present invention, in drying and calcining a catalyst slurry containing a cobalt precursor and an alumina support in the catalyst production method, the drying is performed at a temperature of 5 ℃ to 50 ℃, the firing is 400 ℃ to under the air stream Co ₃ O ₄ / alumina by firing at 600 ℃ The catalyst could be prepared. Thus, the present invention provides Co ₃ O ₄ / alumina The catalyst production method also has its characteristics.

Co ₃ O ₄ / alumina according to the invention The method for preparing a catalyst includes 1) preparing a catalyst slurry by mixing an aqueous solution of cobalt precursor and alumina, 2) drying the catalyst slurry under a temperature condition of 5 ° C. to 50 ° C., and 3) removing the dried catalyst slurry. Co ₃ O ₄ / Alumina by firing at a temperature of 400 ℃ to 600 ℃ under air stream Preparing a catalyst.

First, a catalyst slurry is prepared by mixing a cobalt precursor aqueous solution and an alumina support. The cobalt precursor compound used in the present invention is not particularly limited, but for example, cobalt chloride, cobalt acetate, cobalt nitrate, or a mixture thereof may be used as a precursor compound generally used in the field of catalyst production.

Then, the catalyst slurry is dried and calcined to prepare a catalyst. The drying is performed at a temperature condition of 5 ° C to 50 ° C, preferably at 10 ° C to 40 ° C, more preferably at 20 ° C to 28 ° C, for about 20 to 30 hours. At this time, if the drying temperature is too low, it takes a lot of time, if too high, the cobalt precursor is not uniformly distributed on the alumina support, and agglomeration occurs in one place. Firing may be performed for 1 hour to 3 hours at 400 ° C. to 600 ° C. under air flow. If the firing temperature is less than 400 ℃ cobalt ions do not exist in the form of oxides and are reduced to metal cobalt, and when the firing at a temperature above 600 ℃ the catalyst particles lose the thermal stability and agglomeration occurs There may be a problem that the specific surface area of the catalyst is reduced.

On the other hand, the present invention is Co ₃ O ₄ / alumina It is also characterized by a method of producing an alkylamine by reacting an alcohol under reducing amino using a catalyst.

Alkylamine according to the invention the production method is ⅰ) Co ₃ O ₄ / alumina Contacting the catalyst with a hydrogen gas to activate the catalyst, ii) mixing the alcohol and the amine compound to produce an amination reaction mixture, and iii) subjecting the amination reaction mixture to hydrogen gas and 0.5 to 2.0 atmospheres. And amination reaction while contacting the activated catalyst.

Reductive amination reaction of the present invention is Co ₃ O ₄ / alumina By using a catalyst, sufficient catalytic activity can be obtained even at atmospheric pressure. Therefore, while the conventional manufacturing method has a cumbersome process, such as using a high pressure reactor, the present invention is not particularly limited in the selection of the reactor, using a conventional reactor applied in the art, in particular fixed bed filling It is preferable to carry out in a continuous process using a reactor because it is economical.

In addition, Co ₃ O ₄ / alumina catalyst requires a pre-treatment process to activate before being applied to the reductive amination reaction, in the present invention for the catalyst activation using hydrogen gas in the temperature of 500 ℃ to 700 ℃ 2 hours to 10 hours It is recommended to use the catalyst after sufficiently activating the catalyst. According to the research results of the present inventors, Co ₃ O ₄ / alumina The catalyst was found to change the oxidation number or phase orientation of the cobalt oxide or form an alloy when activated under activation conditions, for example under argon gas, nitrogen gas or air conditions. Thus, the present invention provides Co ₃ O ₄ / alumina It may also be characterized by the use of hydrogen gas for activation of the catalyst.

In the present invention, alcohols and amine compounds are used as amination reactions. The alcohol may be, for example, methanol, ethanol, propanol, isopropyl alcohol, butanol and the like as a monoalcohol compound having 1 to 6 carbon atoms, and isopropyl alcohol is preferably used. The amine compound can typically use ammonia.

The amination reaction described above was activated with Co ₃ O ₄ / alumina. An alkylamine is prepared by reaction under a catalyst and hydrogen stream conditions. At this time, the volume ratio of alcohol to hydrogen is preferably 1: 1 to 20, and the volume ratio of alcohol to amine compound is preferably 1: 1 to 15. The space velocity of the reaction is preferably adjusted to be 0.5 ~ 10.0 h ^-1 . In addition, the temperature of the reaction is preferably 170 ~ 250 ℃, the reaction pressure is preferably maintained at 0.5 ~ 2 atm. Co ₃ O ₄ / alumina of the present invention The amination reaction under the catalyst was able to stably maintain the catalytic activity for a long time even under atmospheric pressure conditions.

The present invention as described above will be described in more detail on the basis of the following examples, it should be understood that the following examples are merely to illustrate the present invention, not to limit the present invention.

[Examples] Preparation of Catalyst

Example 1 4 wt% Co ₃ O ₄ / γ-Al ₂ O ₃ Preparation of the catalyst

0.148 g of cobalt nitrate hexahydrate (Co (NO ₃ ) ₂ .6H ₂ O) as a cobalt precursor was dissolved in 2 ml of distilled water, and this aqueous solution was supported on 1.4 g of a γ-Al ₂ O ₃ support to obtain a catalyst slurry. The catalyst slurry was dried at about 25 ° C. for about one day. Then, the dried catalyst slurry was calcined at 500 ° C. for 2 hours while flowing air. The calcined catalyst thus prepared was impregnated with an aqueous solution in which 0.148 g of cobalt nitrate hexahydrate (Co (NO ₃ ) ₂ · 6H ₂ O), a cobalt precursor, was dissolved in 2 ml of distilled water, and then dried and calcined in the same manner as described above. Through the process, Co ₃ O ₄ / γ-Al ₂ O ₃ having a supported amount of cobalt based on the total weight of the catalyst was 4% by weight.

Example 2 11 wt% Co ₃ O ₄ / γ-Al ₂ O ₃ Preparation of the catalyst

0.445 g of cobalt nitrate hexahydrate (Co (NO ₃ ) ₂ .6H ₂ O) as a cobalt precursor was dissolved in 2 ml of distilled water, and this aqueous solution was supported on 1.4 g of a γ-Al ₂ O ₃ support to obtain a catalyst slurry. The catalyst slurry was dried at about 25 ° C. for about one day. Then, the dried catalyst slurry was calcined at 500 ° C. for 2 hours while flowing air. The calcined catalyst thus prepared was impregnated with an aqueous solution in which 0.445 g of cobalt nitrate hexahydrate (Co (NO ₃ ) ₂ · 6H ₂ O), a cobalt precursor, was dissolved in 2 ml of distilled water, and then dried and calcined in the same manner as described above. After the process, Co ₃ O ₄ / γ-Al ₂ O ₃ having 11 wt% of the supported amount of cobalt based on the total catalyst weight was prepared.

Example 3 17 wt% Co ₃ O ₄ / γ-Al ₂ O ₃ Preparation of the catalyst

0.742 g of cobalt nitrate hexahydrate (Co (NO ₃ ) ₂ .6H ₂ O) was dissolved in 2 ml of distilled water as a cobalt precursor, and this aqueous solution was supported on 1.4 g of a γ-Al ₂ O ₃ support to obtain a catalyst slurry. The catalyst slurry was dried at about 25 ° C. for about one day. Then, the dried catalyst slurry was calcined at 500 ° C. for 2 hours while flowing air. The calcined catalyst thus prepared was impregnated with an aqueous solution in which 0.742 g of cobalt nitrate hexahydrate (Co (NO ₃ ) ₂ · 6H ₂ O), a cobalt precursor, was dissolved in 2 ml of distilled water, and then dried and calcined in the same manner as described above. After the process, Co ₃ O ₄ / γ-Al ₂ O ₃ having a supported amount of cobalt based on the total weight of the catalyst was 17% by weight.

Example 4 23 wt% Co ₃ O ₄ / γ-Al ₂ O ₃ Preparation of the catalyst

1.039 g of cobalt nitrate hexahydrate (Co (NO ₃ ) ₂ .6H ₂ O) as a cobalt precursor was dissolved in 2 ml of distilled water, and this aqueous solution was supported on 1.4 g of a γ-Al ₂ O ₃ support to obtain a catalyst slurry. The catalyst slurry was dried at about 25 ° C. for about one day. Then, the dried catalyst slurry was calcined at 500 ° C. for 2 hours while flowing air. The calcined catalyst thus prepared was impregnated with an aqueous solution in which 1.039 g of cobalt nitrate hexahydrate (Co (NO ₃ ) ₂ · 6H ₂ O), a cobalt precursor, was dissolved in 2 ml of distilled water, and then dried and calcined in the same manner as above. After the process, Co ₃ O ₄ / γ-Al ₂ O ₃ having a supported amount of cobalt based on the total weight of the catalyst was 23% by weight.

Example 5 27 wt% Co ₃ O ₄ / γ-Al ₂ O ₃ Preparation of the catalyst

1.336 g of cobalt nitrate hexahydrate (Co (NO ₃ ) ₂ .6H ₂ O) as a cobalt precursor was dissolved in 2 ml of distilled water, and this aqueous solution was supported on 1.4 g of a γ-Al ₂ O ₃ support to obtain a catalyst slurry. The catalyst slurry was dried at about 25 ° C. for about one day. Then, the dried catalyst slurry was calcined at 500 ° C. for 2 hours while flowing air. The calcined catalyst thus prepared was impregnated with an aqueous solution in which 1.336 g of cobalt nitrate hexahydrate (Co (NO ₃ ) ₂ · 6H ₂ O), a cobalt precursor, was dissolved in 2 ml of distilled water, and then dried and calcined in the same manner. After the process, Co ₃ O ₄ / γ-Al ₂ O ₃ having a supported weight of cobalt based on the total weight of the catalyst was 27% by weight.

Comparative Example 1: 23 wt% Co / γ-Al ₂ O ₃ Preparation of the catalyst

2.079 g of cobalt nitrate hexahydrate (Co (NO ₃ ) ₂ .6H ₂ O) as a cobalt precursor was dissolved in 2 ml of distilled water, and this aqueous solution was supported on 1.4 g of a γ-Al ₂ O ₃ support to obtain a catalyst slurry. The catalyst slurry was dried at 100 ° C. for one day. Then, the dried catalyst slurry was calcined at 400 ° C. for 3 hours while flowing air to prepare Co / γ-Al ₂ O ₃ having a supported amount of cobalt of 23 wt% based on the total catalyst weight.

1 is 23 wt% Co ₃ O ₄ / γ-Al ₂ O ₃ prepared in Example 4. 23 wt% Co / γ-Al ₂ O ₃ prepared in Comparative Example 1 with a catalyst Each catalyst is an X-ray diffraction pattern. According to Figure 1 23 wt% Co ₃ O ₄ / γ-Al ₂ O ₃ prepared in Comparative Example 1 23 wt% Co ₃ O ₄ / γ-Al ₂ O ₃ prepared in Example 4 compared to the catalyst Not only was the catalyst good crystallinity, but the phase shifted slightly.

2 and 3 Co ₃ O ₄ / γ-Al ₂ O ₃ Catalyst and Co / γ-Al ₂ O ₃ The results of the TGA-DTA analysis for each catalyst are attached. According to FIGS. 2 and 3, the solvent is volatilized in the first step to reduce the weight, and when the temperature is higher, the pyrolysis reaction of the sample occurs again in the second step, but the pyrolysis temperature is about 5 ° C .. there was.

Therefore, Co ₃ O ₄ / γ-Al ₂ O ₃ characterized by the present invention The catalyst is a conventional Co / γ-Al ₂ O ₃ It can be seen that the catalyst material is completely different from the catalyst.

Experimental Example Comparative Experiment of Catalytic Activity

Experimental Example 1. Experiment of reductive amination reaction according to cobalt loading of catalyst

0.1 g of the catalyst prepared in Examples 1 to 5 and Comparative Example 1 were charged to a continuously operated fixed bed reactor. Hydrogen gas was introduced into the reactor and maintained at 600 ° C. for 3 hours to activate the catalyst. Then, the temperature inside the reactor was maintained at 210 ° C., and then the isopropyl alcohol, ammonia, and hydrogen were introduced at a flow rate of 2.66, 10.66, 15.99 mL / min, respectively, and the volume ratio of isopropyl alcohol to ammonia was 1: 4. , The volume ratio of isopropyl alcohol: hydrogen was maintained at 1: 6, the space velocity was maintained at 4.29 h ^{- 1} . The results of the reductive amination reaction under each catalyst are shown in Table 1 below.

Analysis of the reaction product shown in Table 1 was performed using gas chromatography (Gas Chromatography, Chrompack, CP 9001), the conversion rate of isopropylamine was calculated as shown in Equation 1 below, the selectivity and yield of isopropylamine and acetone Was calculated as in Equations 2 and 3 below.

[GC analysis condition]

Column: capillary column (length 60 m, 0.32 mm CP-volamine)

Temperature program: 5 minutes holding at 50 ° C., 20 ° C. per minute, 10 milk holdings at 200 ° C.

[Equation 1]

&Quot; (2) "

&Quot; (3) "

division Average
Conversion Rate (%) Selectivity (%) MIPA
yield(%) MIPA Acetone DIPA TEA 4 wt% Co ₃ O ₄ / γ-Al ₂ O ₃ 32.4 76.1 21.8 - 2.1 24.7 11 wt% Co ₃ O ₄ / γ-Al ₂ O ₃ 76.4 72.5 25.0 0.2 2.3 55.4 17 wt% Co ₃ O ₄ / γ-Al ₂ O ₃ 78.1 71.4 25.9 0.4 2.3 55.6 23 wt% Co ₃ O ₄ / γ-Al ₂ O ₃ 81.5 71.6 25.8 0.3 2.3 58.4 27 wt% Co ₃ O ₄ / γ-Al ₂ O ₃ 82.9 71.5 25.7 0.5 2.3 59.1 23 wt% Co / γ-Al ₂ O ₃ 44.5 85.2 13.4 - 1.4 37.9  MIPA: monoisopropylamine, DIPA: diisopropylamine, TEA: triethylamine

According to Table 1, the yield of monoisopropylamine (MIPA) increased as the supported amount of cobalt as an active ingredient increased.

Experimental Example 2 Reductive Amination Activity Experiment According to Alcohol to Hydrogen Ratio

0.1 g of the catalyst prepared in Example 4 (23 wt% Co ₃ O ₄ / γ-Al ₂ O ₃ ) was charged to a continuously operated fixed bed reactor. Hydrogen gas was introduced into the reactor and maintained at 600 ° C. for 3 hours to activate the catalyst. Then, to each of the isopropyl alcohol, ammonia and hydrogen were maintained to the reactor internal temperature to 210 ℃ as the following, the amination reaction were added in a ratio of Table 2, the space velocity of 4.29 h ^- and held to ^one. The results of the reductive amination reaction activity according to the ratio of alcohol to hydrogen are shown in Table 2 below.

Reactant Flow Rate (mL / min) Conversion Rate
(%) Selectivity (%) MIPA
yield(%) IPA NH ₃ H ₂ C _{1 -3} MIPA Acetone DIPA TEA 2.66 10.65 5.33 41.0 · 60.4 35.7 · 3.9 24.8 2.66 10.65 10.65 63.1 · 67.5 29.8 · 2.7 42.5 2.66 10.65 15.98 82.5 · 71.9 26.1 0.2 1.8 59.2 2.66 10.65 21.30 85.3 0.2 74.1 23.3 0.5 1.9 63.2 2.66 10.65 26.63 86.2 0.7 75.5 21.3 0.9 1.6 65.1 2.66 10.65 31.95 90.6 1.0 77.3 18.9 1.3 1.5 70.0 2.66 10.65 37.28 91.1 1.3 77.4 17.9 2.1 1.3 70.5 2.66 10.65 42.60 91.7 1.7 78.5 15.8 2.8 1.2 71.9 C _{1 -3:} a mixture of methane, ethane, propylene, propane MIPA: mono-isopropylamine
DIPA: diisopropylamine TEA: triethylamine

According to Table 2, when the reductive amination reaction was performed in the presence of the catalyst of the present invention, the conversion rate, the selectivity and the yield of monoisopropylamine all increased as the ratio of hydrogen increased. When the volume ratio of isopropyl alcohol to hydrogen was 16, the yield of monoisopropylamine was high as 71.9%. Therefore, it can be seen that under the catalyst characterized by the present invention, alkylamine can be produced in a very high yield even under atmospheric pressure conditions.

Experimental Example 3. Reductive Amination Activity Experiment According to Alcohol to Ammonia Ratio

0.1 g of the catalyst prepared in Example 4 (23 wt% Co ₃ O ₄ / γ-Al ₂ O ₃ ) was charged to a continuously operated fixed bed reactor. Hydrogen gas was introduced into the reactor and maintained at 600 ° C. for 3 hours to activate the catalyst. Then the reactor was kept the inner temperature to 210 ℃ then Ah was as folk reaction was added isopropyl alcohol, ammonia, and hydrogen, respectively were added at a ratio shown in Table 1, space velocity of 4.29 h ^- and held to ^one. The results of the reductive amination reaction activity according to the ratio of alcohol to ammonia are shown in Table 3 below.

Reactant Flow Rate (mL / min) Conversion Rate
(%) Selectivity (%) MIPA
yield(%) IPA NH ₃ H ₂ C _{1 -3} MIPA Acetone DIPA TEA 2.66 0 21.30 78.6 18.0 · 82.0 · · · 2.66 5.33 21.30 83.3 0.7 60.1 35.4 1.2 2.6 50.0 2.66 10.65 21.30 85.3 0.2 74.1 23.3 0.5 1.9 63.2 2.66 15.98 21.30 85.1 · 80.8 17.2 0.5 1.5 68.7 2.66 21.30 21.30 85.7 0.1 85.2 13.7 0.1 0.9 73.0 2.66 26.63 21.30 85.6 0.2 87.0 11.4 0.3 1.1 74.5 2.66 31.95 21.30 88.1 0.2 89.7 9.2 · 0.9 79.0 C _{1 -3:} a mixture of methane, ethane, propylene, propane MIPA: mono-isopropylamine
DIPA: diisopropylamine TEA: triethylamine

According to Table 3, when the reductive amination reaction is carried out in the presence of the catalyst of the present invention, the conversion rate, the selectivity and the yield of monoisopropylamine all increase as the ratio of ammonia increases. When the volume ratio of isopropyl alcohol to ammonia was 12, the yield of monoisopropylamine was as high as 79.0%. Therefore, it can be seen that under the catalyst characterized by the present invention, alkylamine can be produced in a very high yield even under atmospheric pressure reaction conditions.

Experimental Example 4 Experiment of Reductive Amination Activity of Catalyst According to Space Velocity

0.1 g of the catalyst prepared in Example 4 (23 wt% Co ₃ O ₄ / γ-Al ₂ O ₃ ) was charged to a continuously operated fixed bed reactor. Hydrogen gas was introduced into the reactor and maintained at 600 ° C. for 3 hours to activate the catalyst. Then, the temperature inside the reactor was maintained at 210 ° C., and then, isopropyl alcohol, ammonia, and hydrogen were added as the amination reactants in the ratios of Table 4, respectively, and a reducing amination reaction was performed while changing the space velocity. The results are shown in Table 4 below.

Reactant Flow Rate (mL / min) space
speed
(h ^-1 ) Conversion Rate
(%) Selectivity (%) MIPA
yield(%) IPA NH ₃ H ₂ C _{1 -3} MIPA Acetone DIPA TEA 3.26 19.54 26.05 5.24 81.3 · 80.2 18.0 0.3 1.5 65.2 2.66 15.99 21.32 4.29 85.1 · 80.8 17.2 0.5 1.5 68.7 2.07 12.43 16.58 3.34 85.9 0.2 79.5 18.2 0.6 1.5 68.3 1.48 8.88 11.84 2.38 89.3 0.5 79.6 18.1 0.4 1.4 70.8 0.89 5.33 7.11 1.43 91.4 1.2 77.9 18.5 1.0 1.4 71.1 C _{1 -3:} a mixture of methane, ethane, propylene, propane MIPA: mono-isopropylamine
DIPA: diisopropylamine TEA: triethylamine

According to Table 4, when the reductive amination reaction was carried out in the presence of the catalyst of the present invention, the conversion rate, selectivity and yield of monoisopropylamine increased as the space velocity decreased, but the amount of by-products also increased.

Experimental Example 5 Experiment of Reductive Amination Activity of Catalyst According to Reaction Temperature

0.1 g of the catalyst prepared in Example 4 (23 wt% Co ₃ O ₄ / γ-Al ₂ O ₃ ) was charged to a continuously operated fixed bed reactor. Hydrogen gas was introduced into the reactor and maintained at 600 ° C. for 3 hours to activate the catalyst. Then, the internal temperature of the reactor was maintained as shown in Table 5, and then, as amination reaction, isopropyl alcohol, ammonia, and hydrogen were introduced at a flow rate of 2.66, 15.99, and 31.97 mL / min, respectively. : 6, isopropyl alcohol: the volume ratio of hydrogen was maintained at 1: 12, the space velocity was maintained at 4.29 h ^{- 1} . The results of the reductive amination reaction according to the reaction temperature change are shown in Table 5 below.

Reaction temperature
(℃) Conversion Rate
(%) Selectivity (%) MIPA
yield(%) C _{1 -3} MIPA Acetone DIPA TEA 170 82.7 · 88.0 10.6 0.9 0.5 72.8 190 90.7 · 87.3 11.0 0.9 0.8 79.7 210 94.2 0.9 82.2 14.6 1.0 1.3 77.4 230 94.0 2.6 74.5 19.8 1.2 1.9 70.0 250 94.1 6.1 63.1 26.4 1.7 2.7 59.4 C _{1 -3:} a mixture of methane, ethane, propylene, propane MIPA: mono-isopropylamine
DIPA: diisopropylamine TEA: triethylamine

According to Table 5, when the reductive amination reaction was carried out in the presence of the catalyst of the present invention, the conversion rate increased with increasing reaction temperature, and the selectivity of monoisopropylamine decreased with increasing reaction temperature. . The yield of monoisopropylamine according to the reaction temperature was highest as 79.7% at 190 ℃.

Experimental Example 6 Experiment for Determining Activity Reduction of Catalyst Over Time

A fixed bed continuously operated with 0.1 g of the catalyst prepared in Example 4 (23 wt% Co ₃ O ₄ / γ-Al ₂ O ₃ ) and the catalyst prepared in Comparative Example 1 (Co / γ-Al ₂ O ₃ ), respectively Charged into the reactor. Hydrogen gas was introduced into the reactor and maintained at 600 ° C. for 3 hours to activate the catalyst. Then, the temperature inside the reactor was maintained at 190 ° C., and then the isopropyl alcohol, ammonia, and hydrogen were introduced at a flow rate of 2.66, 15.99, 31.97 mL / min, respectively, and the volume ratio of isopropyl alcohol to ammonia was 1: 6. , Volume ratio of isopropyl alcohol: hydrogen was maintained at 1: 12, and the space velocity was maintained at 4.29 h ^{- 1} . The results of the reductive amination reaction according to the reaction time change are shown in Table 6 below.

Reaction time
(h) 23 wt% Co ₃ O ₄ / γ-Al ₂ O ₃
(Example 4) 23 wt% Co / γ-Al ₂ O ₃
(Comparative Example 1) Conversion Rate
(%) MIPA
Selectivity (%) MIPA
yield(%) Conversion Rate
(%) MIPA
Selectivity (%) MIPA
yield(%) 0.08 90.7 87.3 79.2 27.4 96.4 26.4 One 90.8 87.4 79.4 32.8 94.8 31.1 10 91.2 87.5 79.8 45.2 85.3 38.5 30 90.9 87.7 79.7 42.1 85.2 35.8 60 90.7 87.7 79.5 31.6 90.4 28.5 200 90.8 87.6 79.6 24.7 92.2 22.7

According to the Table 6, the Co ₃ O ₄ / alumina catalyst of the present invention almost no catalyst deactivation phenomenon even if the operation for more than 60 hours, whereas the Co / alumina catalyst of Comparative Example 1 catalyst deactivation after 30 hours The selectivity and yield of monoisopropylamine was significantly reduced. Accordingly, the Co ₃ O ₄ / alumina catalyst of the present invention was found to not decrease the activity of the catalyst for a long time under the reaction conditions of normal pressure.

Claims (11)

Co ₃ O ₄ / Alumina used for the reaction of reductive amination of alcohol at 0.5 to 2.0 atmospheres catalyst.
The catalyst according to claim 1, wherein the supported amount of cobalt is in the range of 4 to 30% by weight based on the total weight of the catalyst.
Preparing a catalyst slurry by mixing cobalt precursor aqueous solution and alumina;
Drying the catalyst slurry at a temperature of 5 ° C. to 50 ° C .; And
The dried catalyst slurry was calcined at 400 to 600 ° C. under an air stream to produce Co ₃ O ₄ / alumina. Preparing a catalyst;
Method for producing a Co ₃ O ₄ / alumina catalyst for reductive amination reaction of alcohol comprising a.
The method of claim 3, wherein the cobalt precursor is cobalt chloride, cobalt acetate, cobalt nitrate, or a mixture thereof.
The method of claim 3, wherein the catalyst slurry is dried at a temperature of 10 ° C. to 40 ° C. 5.
The method of claim 3, wherein the catalyst slurry is dried at a temperature of 20 ° C. to 28 ° C. 5.
Contacting the catalyst of claim 1 to hydrogen gas to activate the catalyst;
Mixing an alcohol and an amine compound to prepare an amination reaction mixture;
Amination of the amination reaction mixture in contact with the activated catalyst at a hydrogen gas stream and 0.5 to 2.0 atmospheres of pressure;
Method for producing an alkylamine comprising a.
8. The method of claim 7, wherein the alcohol is isopropyl alcohol, the amine compound is ammonia, and the alkylamine is monoisopropylamine.
8. The method of claim 7, wherein the volume ratio of alcohol to hydrogen in the amination reaction is in the range of 1: 1 to 20.
The method for producing an alkylamine according to claim 7, wherein the volume ratio of the alcohol: amine compound in the amination reaction is 1: 1-15.
The method of claim 7, wherein the amination reaction is a method for producing an alkylamine, characterized in that carried out at 170 ~ 250 ℃ reaction temperature and 0.5 ~ 10.0 h ^-1 space velocity conditions.

Images