KR101242685B1 - Method for preparing isopropanol using bottom-up flow system - Google Patents

Abstract

The present invention relates to a method for preparing isopropanol, and more particularly, to a method for preparing isopropanol, comprising hydrogenation of acetone in the presence of a catalyst. It is a bottom-up bottom-up method, and relates to a method for producing isopropanol, characterized in that the active metal content in the catalyst is 10 to 20% by weight.

Method for producing isopropanol according to the present invention using a catalyst having an active metal content of 10 to 20% by weight and at the same time using a bottom-up (bottom-up); bottom-up flow process; Compared to the top-down flow process, high-temperature reaction heat generated during the hydrogenation of acetone can be effectively controlled, and high-purity isopropanol can be produced in a continuous process by preventing the channeling phenomenon and increasing the reaction yield. There are advantages to it.

Acetone, Hydrogenation, Isopropanol, Bottom Up, Bottom Entry-Top Removal

Description

Method for producing isopropanol using bottom injection-top removal flow process {METHOD FOR PREPARING ISOPROPANOL USING BOTTOM-UP FLOW SYSTEM}

[Industrial use]

The present invention relates to a method for producing isopropanol, and more particularly, it is possible to effectively control the high-temperature reaction heat generated during the hydrogenation reaction of acetone, and to prevent the channeling phenomenon and increase the reaction yield, and isopropanol of high purity in a continuous process It relates to a method for producing isopropanol which can be prepared by.

BACKGROUND ART [0002]

Isopropanol is widely used in the field of organic synthesis, such as used as a raw material and organic solvent of cumene, isopropylamine, isopropyl ether, and the like.

As a method for producing isopropanol, a method for producing by isolating propylene and a method for producing by isolating acetone with hydrogenation are known.

As an example of a method for producing isopropanol by hydrogenation of acetone in the above production method, US Patent No. 5,081,321 discloses hydrogen and acetone in a reactor having a fixed catalyst layer [Lini Ni alloy (Ni / Al)]. A process for hydrogenation is disclosed, and US Patent No. 4,182,721 discloses a process for hydrogenating carbonyl compounds based on Raney nickel containing molybdenum.

U.S. Patent No. 5,449,839 also discloses a process for preparing isopropanol by hydrogenation of gaseous acetone in the first step of the two-step reaction for preparing isopropyl-tertiary butyl ether. 5,684,215 discloses a process for preparing alcohols by reaction of hydrogen with carbonyl compounds such as ketones and aldehydes at temperatures of 60 to 150 ° C. using catalysts containing nickel, aluminum and zirconium.

In addition, U. S. Patent No. 6,939, 995 prepares isopropanol from acetone containing 1% or less of benzene as an impurity, and flows acetone in a fixed catalyst layer having a nickel content of 25% or more and a nickel surface area of 15 m2 / g or more (top of the reactor). To a raw material is added to obtain a product at the bottom of the reactor.

However, since the hydrogenation of acetone is basically an exothermic reaction, it is difficult to control the temperature during the preparation of isopropanol, and by-products are generated by side reactions due to the temperature rise, thereby reducing the conversion of acetone, and safety due to temperature rise in the reactor. There is a problem of deterioration, and there is a disadvantage in that the production efficiency is lowered because it introduces a manufacturing process and a reactor of a complicated structure to control the heat of reaction.

In addition, in the process of obtaining a product at the bottom of the reactor by adding the reactant to the top of the reactor, the reaction temperature can be easily controlled when the catalyst layer in the reactor is small, but when using a large-capacity reactor for industrial applications It is difficult to control, the temperature distribution in the reactor is not constant, it is difficult to add the reactant evenly to the entire catalyst surface, the reaction yield is reduced by the channeling (channeling) phenomenon.

In order to solve the above problems, the present invention can effectively control the high-temperature reaction heat generated during the hydrogenation of acetone, and prevent the channeling phenomenon and at the same time increase the reaction yield to produce a high-purity isopropanol It aims to provide.

In order to achieve the above object,

In the presence of a catalyst, in the production method of isopropanol comprising the step of hydrogenation (acegen) reaction (acetone),

It provides a method for producing isopropanol, characterized in that the flow of the reactant in the reactor is a bottom-up (bottom-up) method, the active metal content in the catalyst is 10 to 20% by weight.

Hereinafter, the present invention will be described in more detail.

In the course of studying the method for producing isopropanol using acetone, the present inventors used a catalyst having an active metal content of 10 to 20% by weight and simultaneously reacted the reaction product with a bottom-up flow. When reacting in the process, the reaction heat control effect is superior to that of the reaction in the top-down flow process, reducing side reactions, and confirming the ease of application to the continuous mass production process. Based on this, the present invention has been completed.

Since hydrogenation of acetone is basically exothermic, it is difficult to control the temperature, and by-products are generated by side reactions due to the temperature rise, which lowers the conversion of acetone, and it is difficult for the reactants to be evenly introduced into the entire catalyst surface. There is a disadvantage that the reaction yield is lowered by the channeling phenomenon.

On the other hand, in the method for preparing isopropanol according to the present invention, as acetone and hydrogen, which are reaction raw materials, are injected into the bottom of the reactor, and isopropanol, which is a product, is obtained at the top of the reactor. There is an advantage that can maintain a constant reaction temperature as a whole, thereby reducing side reactions. In addition, in the production method of the present invention, since the reactants are sequentially filled from the bottom of the reactor, the reactants are evenly added to the entire fixed bed catalyst surface, and all the catalysts in the reactor are used to increase the yield of the product. There is an advantage that can be solved, such as a large temperature deviation inside the reactor, difficulty in evenly adding the reactant, reduction of the overall catalyst utilization in the reactor due to the channeling phenomenon, which is a disadvantage when the input to the top.

In the present invention, the 'bottom-up' and 'bottom-up' flows mean opposite to the 'bottom-up' and 'top-down' flows.

Method for producing isopropanol according to the present invention is a method for producing isopropanol comprising the step of hydrogenation of acetone (acetone) in the presence of a catalyst having an active metal content of 10 to 20% by weight, the reactant in the reactor The flow of the bottom is characterized in that the bottom-up (bottom-up) method.

That is, the present invention in the step of the gas-liquid contact reaction of hydrogen gas and liquid acetone in the reactor in which the hydrogenation catalyst is fixed, by reacting the reactant to the bottom of the reactor and removing the product to the top to control the reaction heat It relates to an easy manufacturing method.

Among the reaction raw materials in the above step, hydrogen and acetone are most preferably used pure ones containing no impurities, and the present invention is not limited thereto because it does not affect the effects of the present invention.

For example, the hydrogen may be pure or may contain impurities such as methane, ethane and nitrogen. The acetone may also be pure, and the hydrogenated reaction may be used to recover and reuse unreacted acetone. Since acetone is generally obtained from a by-product of the phenol process, an acetone-containing aromatic compound may be used.

In the hydrogenation step of the present invention, it is preferable to react by adding hydrogen so that the molar ratio of acetone: hydrogen is 1: 1 to 1: 3. In other words, when the molar ratio is low, the acetone: hydrogen molar ratio is preferably 1: 1 or more, considering that the reaction conversion rate is low and the selectivity is low, and when the ratio of hydrogen is high, the cost of recovering and recycling it becomes high and the economy is inferior. In consideration, it is preferable that the molar ratio of acetone: hydrogen is 1: 3 or less.

The catalyst is an active metal selected from the group consisting of nickel, platinum, palladium, ruthenium and rhodium; And a carrier selected from the group consisting of alumina, silica, zirconia and titania.

In particular, in the present invention, it is preferable to use the catalyst having an active metal content of 10 to 20% by weight in the catalyst. In other words, the active metal content in the catalyst is preferably at least 10% by weight so as to exhibit a minimum reaction activity effect, in order to prevent the heat of reaction from increasing during the hydrogenation of acetone and to reduce the production rate of isopropanol It is preferred that the content is 20% by weight or less.

According to the present invention, after the hydrogenation step, the step of separating the excess gas from the hydrogenation reaction product, to obtain a liquid reaction product; Separating unreacted acetone from the liquid reaction product and obtaining purified isopropanol; And recycling the unreacted acetone to the hydrogenation step to produce isopropanol in a continuous type.

The continuous reaction steps may be combined with steps that are conventional in the art, but is not particularly limited thereto.

Preferred reaction conditions of the continuous process, the weight hourly space Velocity (WHSV) 0.1 to 5.0 hr ^-1 in the hydrogenation reaction step, carried out at a reaction temperature of 70 to 150 ℃ and a reaction pressure of 10 to 50 atmosphere It is preferable.

That is, the WHSV is preferably 0.1 hr ^-1 or more because it is difficult to achieve economic productivity when the amount of the reactants introduced into the reactor is small, and 5.0 hr ^-1 or less in consideration of the conversion rate of the reactants. In addition, the reaction temperature is preferably 70 ℃ or more in order to supply a minimum reaction activation energy, it is preferable that the by-products generated by decomposition of acetone and deformation of isopropanol when the temperature is high is preferably 150 ℃ or less. In addition, the reaction pressure is preferably at least 10 atm considering the minimum conversion rate, and preferably at most 50 atm considering the economical efficiency of the reaction such as the cost for maintaining the high pressure and the effect of increasing the conversion rate.

Hereinafter, preferred examples and comparative examples of the present invention are described.

The following Examples and Comparative Examples are only described for the purpose of more clearly expressing the present invention, but the contents of the present invention are not limited to the following Examples and Comparative Examples.

Example  One

A tubular reactor 2.54 cm in diameter and 15.24 cm in length was charged with 70 g of a catalyst (18% nickel, 82% alumina, manufactured by KATA LEUNA, product name: KL-6560), and the initial, upper, middle and lower portions of the reactor. The temperature was measured, and the reaction was carried out without supplying a heat source to compare the exothermic degree according to the active metal content of the catalyst and the reactant flow direction.

At this time, the reactant acetone was injected to the bottom of the reactor at a rate of mass space velocity (WHSV) = 1.0 hr ⁻¹ through a pressure pump. In addition, the residence time of the reactants in the reactor was a total of 1 hour, the molar ratio of acetone and hydrogen was maintained at 1: 1, the reaction pressure was maintained at 30 atm. While reacting under the above conditions, the maximum temperature of the reactions of the upper, middle, and lower portions of the reactor was measured, and the results are shown in Table 1 below.

Comparative example  1 and 2

As shown in Table 1, it was carried out in the same manner as in Example 1, except that the type of catalyst (active metal content) and the reactant flow direction was changed.

division catalyst
Kinds Acetone:
Hydrogen (molar ratio) Reactant
flow Maximum (initial) temperature (℃) by reactor site Top Central bottom Example 1 a 1: 1 Bottom-up 120 (24) 106 (32) 43 (24) Comparative Example 1 a 1: 1 Top-down 140 (28) 132 (29) 79 (27) Comparative Example 2 b 1: 1 Top-down 179 (27) 150 (25) 123 (26)

Note) Catalyst a: Nickel (18%)-alumina (82%), Cataluna (KL-6560)

   Catalyst b: Nickel (28%)-Alumina (72%), Cataluna (KL-6564)

As shown in Table 1, Example 1 uses a catalyst having an active metal content of 18% and reacts in a bottom-up manner, thus the top-down is removed. Compared to Comparative Example 1 reacted in a manner, the reaction heat for each site was about 27 ℃ average, which is advantageous to the reaction heat control. In addition, in Comparative Example 2 using a catalyst having an active metal content of 28%, the heat of reaction was higher than that of Comparative Example 1.

Example  2

Fill a tubular reactor 2.54 cm in diameter and 15.24 cm in length with 70 g of catalyst (18% nickel, 82% alumina, manufactured by KATA LEUNA, product name: KL-6560), and keep the reactor internal temperature at 90 ° C. The reaction proceeded by heating or cooling.

At this time, the reactant acetone was injected into the bottom of the reactor (bottom-up) at a rate of mass space velocity (WHSV) = 2.0 hr ^-1 . In addition, the residence time of the reactants in the reactor was 30 minutes in total, the mole ratio of acetone and hydrogen was maintained at 1: 1, the reaction pressure was maintained at 30 atm.

After completion of the reaction, the isopropanol conversion of acetone was analyzed by gas chromatography, and the results are shown in Table 2 below.

Example  3

As shown in Table 2 below, the reaction was performed in the same manner as in Example 2, except that the reaction was performed while heating or cooling the reactor internal temperature to 110 ° C.

Comparative example  3 to 8

As shown in Table 2 below, the reaction was carried out in the same manner as in Example 2, except that the type of catalyst (active metal content), the reactant flow direction, and the reactor internal temperature were changed.

division catalyst
Kinds Acetone:
Hydrogen (molar ratio) Reactor
Internal temperature (℃) Reactant
flow Acetone
Conversion Rate (%) Example 2 a 1: 1 90 Bottom-up 99.96 Example 3 a 1: 1 110 Bottom-up 99.95 Comparative Example 3 a 1: 1 90 Top-down 97.84 Comparative Example 4 a 1: 1 110 Top-down 97.16 Comparative Example 5 b 1: 1 90 Top-down 63.28 Comparative Example 6 b 1: 1 110 Top-down 88.10 Comparative Example 7 b 1: 1 90 Bottom-up 71.24 Comparative Example 8 b 1: 1 110 Bottom-up 97.90

Note) Catalyst a: Nickel (18%)-alumina (82%), Cataluna (KL-6560)

   Catalyst b: Nickel (28%)-Alumina (72%), Cataluna (KL-6564)

As shown in Table 2, when the flow of the reactants is a bottom-up method, the conversion rate of acetone to isopropanol is lower than that of the top-down method under the same reaction conditions. It can be seen that high.

Particularly, Examples 2 and 3 use a catalyst having an active metal content of 28% and a catalyst having an active metal content of 28% and using a bottom-up bottom-up method and a catalyst having an active metal content of 18%. Compared to Comparative Examples 5 and 6 reacted by the top-down method and Comparative Examples 7 and 8 which were the same bottom-up method, the reaction heat was easier to control, and the conversion rate of acetone to isopropanol was also higher. High.

Although Comparative Examples 3 and 4 used the same type of catalyst as in Examples 2 and 3, the reaction heat was difficult to control by reacting in a top-down manner, and the conversion of acetone to isopropanol was also reduced. Appeared to fall.

As described above, the method for producing isopropanol according to the present invention uses a bottom-up flow process, compared with the case of reacting with acetone in a top-down flow process. It is possible to effectively control the high temperature reaction heat generated during the hydrogenation reaction, and to prevent the channeling phenomenon and increase the reaction yield has the advantage of producing a high purity isopropanol in a continuous process.

Claims (7)

In the presence of a catalyst, in the production method of isopropanol comprising the step of hydrogenation (acegen) reaction (acetone), A method of producing isopropanol, characterized in that the flow of the reactants in the reactor is a bottom-up bottom-up method, the active metal content in the catalyst is 10 to 20% by weight. The method of claim 1, The catalyst is an active metal selected from the group consisting of nickel, platinum, palladium, ruthenium and rhodium; And a carrier selected from the group consisting of alumina, silica, zirconia and titania. The method of claim 1, The hydrogenation reaction is a method for producing isopropanol by adding hydrogen so that the molar ratio of acetone: hydrogen is 1: 1 to 1: 3. The method of claim 1, The hydrogenation reaction is carried out at a reaction temperature of 70 to 150 ℃, reaction pressure 10 to 50 atm. According to claim 1, After the hydrogenation step, Separating excess gas from the hydrogenation reaction product and obtaining a liquid reaction product; Separating unreacted acetone from the liquid reaction product and obtaining purified isopropanol; And Recycling the unreacted acetone to the hydrogenation step Method for producing isopropanol further comprising. The method of claim 5, The hydrogenation reaction is a method of producing isopropanol is a continuous type process of the weight hourly space (Weight Hourly Space Velocity) is 0.1 to 5.0 hr ^-1 . The method of claim 1, The hydrogenation is isopropanol is a method for producing isopropanol conversion of more than 99.0% of acetone.