KR20220060334A - Method for purifying alcohol compound - Google Patents

Abstract

The present invention relates to a method for purifying an alcohol-based compound. Particularly, the method according to the present invention includes the steps of: (S10) carrying out transesterification of a reaction mixture containing a first alcohol-based compound and a first ester-based compound to obtain a reaction product containing the first alcohol-based compound, a second alcohol-based compound and a second ester-based compound; and (S20) supplying the reaction product to a first distillation tower to discharge a bottom discharge stream containing the first alcohol-based compound and the second ester-based compound, and a top discharge stream containing the second alcohol-based compound.

Description

Method for purifying alcohol-based compounds {METHOD FOR PURIFYING ALCOHOL COMPOUND}

The present invention relates to a method for purifying an alcohol-based compound, and more particularly, to a method for purifying an alcohol-based compound containing an ester-based compound as an impurity with high purity.

In general, octanol such as 2-ethylhexanol is used as a raw material such as a plasticizer or acrylate, or used in a solvent or stabilizer field, etc. It is formed so large that it amounts to several million tons per year. Many octanol plants in commercial operation are also operated in large-scale plant units of 100,000 tons or more.

On the other hand, when the octanol is used as a raw material such as a plasticizer or acrylate, it goes through a reaction process. cause it to deteriorate. Therefore, in such a large-scale plant, the management of by-products and the appropriate treatment for them are an important issue.

As such, in order to purify octanol including by-products, a distillation process is performed. When an ester-based compound having a small boiling point difference from octanol is included as an impurity, the separation efficiency through the distillation process is low, and this separation efficiency is increased In order to do this, the number of theoretical plates or the reflux ratio in the distillation column needs to be increased, so there is a problem in that the energy and cost consumed in the distillation process increase.

KR 2010-0138860 A

The problem to be solved in the present invention is, in order to solve the problems mentioned in the technology that is the background of the invention, an alcohol-based compound containing an ester-based compound having a small boiling point difference from an alcohol-based compound as an impurity through a distillation process An object of the present invention is to provide a method capable of reducing energy and cost consumed in a distillation process while refining to a high purity.

According to one embodiment of the present invention for solving the above problems, the present invention is a transesterification reaction of a reactant comprising a first alcohol-based compound and a first ester-based compound, the first alcohol-based compound , obtaining a reaction product comprising a second alcohol-based compound and a second ester-based compound (S10); and supplying the reaction product to the first distillation column to discharge a bottom discharge stream including the first alcohol-based compound and the second ester-based compound, and a top discharge stream including the second alcohol-based compound (S20). It provides a method for purifying an alcohol-based compound comprising.

The method for purifying an alcohol-based compound according to the present invention, while purifying an alcohol-based compound containing an ester-based compound having a small boiling point difference from the alcohol-based compound as an impurity through a distillation process to high purity, energy and cost consumed in the distillation process can be reduced

1 is a view showing that in Example 1, Example 2 and Comparative Example 1 of the present invention, 2-ethylhexanol of the same purity contained in the bottom discharge stream of the first distillation column is discharged, (a) by the number of theoretical plates of the first distillation column; It is a graph showing the reflux ratio, and (b) the amount of heat for each theoretical plate in the first distillation column.

The terms or words used in the description and claims of the present invention should not be construed as being limited to their ordinary or dictionary meanings, and the inventor must properly understand the concept of the term in order to best describe his invention. Based on the principle that can be defined, it should be interpreted as meaning and concept consistent with the technical idea of the present invention.

In the present invention, the term "upper" means a portion corresponding to a height of 50% or more from the total height of the device in the container, and "lower" means a portion corresponding to a height of less than 50% from the total height of the container or device. can

In the present invention, the term “stream” may mean a flow of a fluid in a process, and may also mean a fluid itself flowing in a pipe. Specifically, the "stream" may mean both the fluid itself and the flow of the fluid flowing within a pipe connecting each device. In addition, the fluid may refer to a gas or a liquid.

In the present invention, the term 'transesterification reaction' may be a reaction in which an alcohol or other ester-based compound is reacted with an ester-based compound in the presence of an acid or base catalyst to generate a new ester-based compound by exchanging an alkyl group. there is. Specifically, the transesterification reaction may be carried out through the following Reaction Scheme 1.

[Scheme 1]

In Scheme 1, the first ester-based compound represented by RCOOR' may be an alkyl, cycloalkyl, aryl or alkaryl ester of a saturated or unsaturated aliphatic or aromatic carboxylic acid, where R is the carboxylic acid A saturated or unsaturated aliphatic or aromatic moiety, and R' may be alkyl, cycloalkyl, aryl or alkaryl, but is not limited thereto. In addition, in the first alcohol-based compound represented by R"OH, R" may be alkyl, alkoxyalkyl or cycloalkyl, but is not limited thereto.

Hereinafter, the present invention will be described in more detail to help the understanding of the present invention.

According to the present invention, there is provided a method for purifying an alcohol-based compound. In the method for purifying the alcohol-based compound, a reactant including a first alcohol-based compound and a first ester-based compound is subjected to a transesterification reaction, and the first alcohol-based compound, the second alcohol-based compound and the second ester are subjected to a transesterification reaction. obtaining a reaction product including a system compound (S10); and supplying the reaction product to the first distillation column to discharge a bottom discharge stream including the first alcohol-based compound and the second ester-based compound, and a top discharge stream including the second alcohol-based compound (S20). may include

In general, octanol such as 2-ethylhexanol is used for various purposes, such as being used as a raw material such as a plasticizer or acrylate, or used in a solvent or stabilizer field. Many octanol plants in commercial operation are also operated in large-scale plant units of 100,000 tons or more.

On the other hand, when the octanol is used as a raw material such as a plasticizer or acrylate, it goes through a reaction process. cause it to deteriorate. Therefore, in such a large-scale plant, the management of by-products and the appropriate treatment for them are an important issue.

As such, in order to purify octanol containing by-products, a distillation process is performed. When an ester-based compound having a small difference in boiling point from octanol is included as an impurity, the separation efficiency through the distillation process is low. In order to increase the separation efficiency, it is necessary to increase the number of theoretical plates or the reflux ratio in the distillation column, so there is a problem in that the energy and cost consumed in the distillation process increase.

Accordingly, in the present invention, an alcohol-based compound containing an ester-based compound having a small boiling point difference from an alcohol-based compound as an impurity is purified to a high purity through a distillation process while reducing energy and cost consumed in the distillation process. It is intended to provide a method for purifying a compound.

According to an embodiment of the present invention, in step (S10), a reactant including a first alcohol-based compound and a first ester-based compound is transesterified, and the first alcohol-based compound, the second alcohol-based compound, and It may be a step of obtaining a reaction product including the second ester-based compound.

Specifically, the reactant may include a first alcohol-based compound containing the first ester-based compound as a by-product. That is, the target object to be purified in the method for purifying an alcohol-based compound according to the present invention may be the first alcohol-based compound.

More specifically, through the transesterification reaction of the first alcohol-based compound and the first ester-based compound having a relatively small boiling point difference, the first ester-based compound is converted into a second alcohol having a relatively large boiling point difference from the first alcohol-based compound. It can be converted into a compound and a second ester compound.

That is, the difference in boiling points between the first alcohol-based compound and the first ester-based compound is the difference in boiling points between the first alcohol-based compound and the second alcohol-based compound, and the boiling points of the first alcohol-based compound and the second ester-based compound may be less than the difference.

For example, the difference between the boiling points of the first alcohol-based compound and the first ester-based compound is 1 to 30 °C, 10 to 20 °C, or 15 to 20 °C, and the difference between the boiling points of the first alcohol-based compound and the second alcohol-based compound is The boiling point difference and the boiling point difference between the first alcohol-based compound and the second ester-based compound may each independently be 50 to 100 °C, 50 to 80 °C, or 50 to 70 °C.

In the reactant, the first ester-based compound may be included in an amount of 0.1 to 3% by weight, 0.1 to 2% by weight, or 0.1 to 1% by weight of the first alcohol-based compound. Within this range, the conversion rate of the first ester-based compound to the second alcohol-based compound and the second ester-based compound may be 99.0% or more, 99.5% or more, or 99.9% or more.

The transesterification reaction is titanium (IV) 2-ethylhexyl oxide, titanium (IV) n-butoxide, titanium (IV) methoxide, titanium (IV) ethoxide, titanium (IV) propoxide, and titanium ( IV) It may be carried out in the presence of one or more catalysts selected from the group consisting of isopropoxide, and any catalyst capable of accelerating the transesterification reaction of the first alcohol-based compound and the first ester-based compound may be used without limitation. can

As a specific example, the catalyst may be titanium (IV) 2-ethylhexyl oxide or titanium (IV) n-butoxide. As a more specific example, when the first alcohol-based compound is 2-ethylhexanol and the first ester-based compound is butyl butyrate, titanium (IV) 2-ethylhexyl oxide or titanium (IV) n- as the catalyst Butoxide may be used, and as a result of the transesterification reaction, n-butanol, which is the second alcohol-based compound, and 2-ethylhexylbutyrate, which is the second ester-based compound, may be produced.

At this time, when titanium (IV) 2-ethylhexyl oxide is used as the catalyst, a part of the ligand attached to the titanium (IV) 2-ethylhexyl oxide may be eluted with 2-ethylhexanol due to a side reaction during the catalytic reaction. However, since it is the same alcohol-based compound as 2-ethylhexanol, which is the first alcohol-based compound, there is an advantage that it does not act as a new by-product. In addition, when titanium (IV) n-butoxide is used as the catalyst, a part of the ligand attached to titanium (IV) n-butoxide may be eluted as n-butanol due to a side reaction during the catalytic reaction. Since it is the same alcohol-based compound as n-butanol, which is an alcohol-based compound, there is an advantage that it does not act as a new by-product.

On the other hand, for example, when titanium (IV) ethoxide is used as the catalyst, a part of the ligand attached to the titanium (IV) ethoxide may be eluted with ethanol due to a side reaction during the catalytic reaction, which is the first alcohol. Since it is an alcohol-based compound different from 2-ethylhexanol, which is the system compound, or n-butanol, which is the second alcohol-based compound, there is a disadvantage in that it acts as a new by-product.

That is, it may be preferable to selectively use a catalyst that does not generate new impurities according to the type of the first alcohol-based compound as the target object and the first ester-based compound as an impurity contained therein.

In this case, the catalyst may be used in an amount of 0.005 to 0.01 mole, 0.005 to 0.008 mole, 0.005 to 0.006 mole relative to 1 mole of the first alcohol-based compound. In this case, there is an excellent effect of converting the first ester-based compound through the transesterification reaction while using a small amount of the catalyst.

The transesterification reaction may be performed at 100 to 200 °C, 110 to 180 °C, or 120 to 150 °C for 0.5 to 10 hours, 0.5 to 6 hours, or 0.5 to 3 hours. Within this range, it exhibits high catalytic activity and promotes the transesterification reaction, thereby having the effect of shortening the reaction time.

The first alcohol-based compound is 2-ethylhexanol, isopropanol, isobutanol, isononanol, sec-butanol, cyclohexanol, n-heptanol, isoheptanol, 2-octanol, cyclohexyloctanol, 1 It may be at least one selected from the group consisting of -methylheptanol and 3,5,5-trimethylhexanol, and any alcohol-based compound having a hydroxyl group (-OH) may be used without limitation. As a specific example, the first alcohol-based compound may be 2-ethylhexanol.

In addition, the first ester-based compound is butyl butyrate, methyl burate, ethyl butylate, hexyl burate, octyl burate, methyl formate, ethyl formate, propyl formate, butyl formate, methyl acetate, ethyl acetate , propyl acetate, butyl acetate, methyl propionate, ethyl propionate, propyl propionate, and may be at least one selected from the group consisting of butyl propionate, if the ester compound having an ester group (-COOR') It can be used without limitation. As a specific example, the first ester-based compound may be butyl butyrate.

For example, when the first alcohol-based compound is 2-ethylhexanol and the first ester-based compound is butylbutyrate, the boiling point of 2-ethylhexanol is 184.7°C, and the boiling point of butylbutyrate is is 166 ° C., the difference in boiling point between the two components is not large, and in order to increase the separation efficiency between the two components, the number of theoretical plates or the reflux ratio of the distillation column in which the distillation process is performed must be high, so energy consumed and installation cost can significantly increase there is.

However, in the method for purifying an alcohol-based compound according to the present invention, the transesterification reaction of 2-ethylhexanol (the first alcohol-based compound) and butylbutyrate (the first ester-based compound) through the step (S10) conversion of the butyl butyrate (the first ester-based compound) to n-butanol having a boiling point of 117.7° C. as a second alcohol-based compound, and 2-ethylhexyl butyrate having a boiling point of 237° C. as a second ester-based compound by can do it Accordingly, through the step (S10), butylbutyrate (first ester-based compound) and 2-ethylhexanol (first alcohol-based compound) and n-butanol (second alcohol) each have a boiling point difference of 50° C. or more. compound) and 2-ethylhexyl butyrate (second ester compound).

In this way, along with 2-ethylhexanol (first alcohol-based compound) through step (S10), n-butanol (second alcohol-based compound) having a relatively large boiling point difference from the 2-ethylhexanol (first alcohol-based compound) A reaction product including an alcohol-based compound) and 2-ethylhexyl butyrate (a second ester-based compound) can be obtained, and components in the reaction product can be easily separated through a subsequent distillation process.

According to an embodiment of the present invention, in step (S20), the reaction product is supplied to the first distillation column, the bottom discharge stream including the first alcohol-based compound and the second ester-based compound, and the second alcohol-based compound It may be a step of discharging a top discharge stream comprising

As described above, a reaction product comprising the first alcohol-based compound, the second alcohol-based compound, and the second ester-based compound, obtained through the transesterification reaction of the first alcohol-based compound and the first ester-based compound can be separated through a distillation process by the first distillation column.

Specifically, from the first distillation column, a bottom discharge stream including the first alcohol-based compound and the second ester-based compound and a top discharge stream including the second alcohol-based compound may be discharged.

For example, the first alcohol-based compound is 2-ethylhexanol (bp. 184.7° C.), the second alcohol-based compound is n-butanol (bp. 117.7° C.), and the second ester-based compound is 2 - In the case of ethylhexylbutyrate (bp. 237 ° C.), 2-ethylhexanol and 2-ethylhexylbutyrate are as the bottom draw stream of the first distillation column, and n-butanol is the top draw stream of the first distillation column. can be emitted.

When the first alcohol-based compound is 2-ethylhexanol and the first ester-based compound is butylbutyrate, a reaction process for using the 2-ethylhexanol as a raw material such as a plasticizer or acrylate is performed. In this case, the butyl butyrate contained in the 2-ethylhexanol participates in the reaction process and generates unnecessary by-products, which may cause deterioration of the purity of the desired product.

Accordingly, in the method for purifying an alcohol-based compound according to the present invention, 2-ethyl through a transesterification reaction of 2-ethylhexanol, which is the first alcohol-based compound, containing butylbutyrate, which is the first ester-based compound, as an impurity. To obtain a reaction product containing hexanol, n-butanol, which is a second alcohol-based compound, and 2-ethylhexylbutyrate, which is a second ester-based compound, it is obtained by distillation using a first distillation column to obtain 2 having a large boiling point difference. -Ethylhexanol and n-butanol can be easily separated.

In addition, at this time, n-butanol is discharged from the upper part of the first distillation column, and 2-ethylhexanol and 2-ethylhexyl butyrate may be discharged together from the lower part. In the case of the 2-ethylhexyl butyrate, the Compared with butyl butyrate, there is a steric hindrance in the chemical structure, and the possibility of participating in the reaction process as described above is significantly reduced. Even if it is supplied to a reaction process for use as a raw material such as a rate, the generation of by-products is significantly reduced, and the purity of the desired product can be increased.

According to an embodiment of the present invention, in the method for purifying an alcohol-based compound according to the present invention, after the step (S20), the bottom discharge stream of the first distillation column is supplied to the second distillation column, and the second ester-based compound is included. The method may further include discharging the bottom discharge stream and the top discharge stream including the first alcohol-based compound (S30).

The bottom discharge stream of the first distillation column may include a first alcohol-based compound and a second ester-based compound, and the boiling point difference between the first alcohol-based compound and the second ester-based compound is 50 to 100° C., 50 to 80 ℃, or 50 to 70 ℃. Accordingly, the two components can be easily separated through the distillation process by the second distillation column.

For example, when the first alcohol-based compound is 2-ethylhexanol (bp. 184.7° C.) and the second ester-based compound is 2-ethylhexyl butyrate (bp. 237° C.), the 2-ethyl Hexanol may be discharged as a top effluent stream of the second distillation column, and the 2-ethylhexylbutyrate may be discharged as a bottom effluent stream of the second distillation column.

As such, when the distillation process through the second distillation column is additionally performed after the distillation process through the first distillation column, the purity of the first alcohol-based compound to be purified can be significantly improved.

According to an embodiment of the present invention, the content of the first ester-based compound included in the bottom discharge stream of the first distillation column in step (S10), and the top discharge stream of the second distillation column in step (S20) included in The content of the first ester-based compound may be 10 ppm or less, 5 ppm or less, or 1 ppm or less. As such, by minimizing the content of the first ester-based compound included in the first alcohol-based compound through the purification method of the alcohol-based compound according to the present invention, the first alcohol-based compound can be obtained with high purity.

As a specific example, a feed stream including the first alcohol-based compound and the first ester-based compound having a relatively small boiling point difference is supplied to the first distillation column to reduce the amount of the first ester-based compound from the first distillation column to 10 ppm or less , 5 ppm or less, or 1 ppm or less, in order to discharge the first alcohol-based compound as a bottom discharge stream, the number of theoretical plates in the tower must be increased to 10 to 30, so the installation cost increases, and the reflux ratio is 1 to 18 Since it should be increased, the amount of heat consumed for reflux in the first distillation column is significantly increased.

On the other hand, through the purification method of the alcohol-based compound according to the present invention, the first alcohol-based compound, and a feed stream including the second alcohol-based compound and the second ester-based compound having a relatively large boiling point difference therebetween the first By supplying to the distillation column, the first alcohol-based compound containing 10 ppm or less, 5 ppm or less, or 1 ppm or less of the first ester-based compound from the first distillation column is discharged as a bottom discharge stream, or the first alcohol-based compound A feed stream including the compound and the second alcohol-based compound and the second ester-based compound having a relatively large difference in boiling point is continuously supplied to the first distillation column and the second distillation column, and the first ester-based compound from the second distillation column In order to discharge the first alcohol-based compound containing 10 ppm or less, 5 ppm or less, or 1 ppm or less as a top discharge stream, the number of theoretical plates in the first distillation column and the second distillation column may be lowered to 1 to 6, respectively. Installation cost can be reduced, and the reflux ratio can be reduced to 1 to 12, so that the amount of heat consumed for reflux in each distillation column is significantly reduced.

According to an embodiment of the present invention, the purification method of the alcohol-based compound according to the present invention, if necessary, a distillation column (not shown), a condenser (not shown), a reboiler (not shown), a pump (not shown), a compressor (not shown), a mixer (not shown), and a separator (not shown) may be additionally installed.

As mentioned above, although the method for purifying an alcohol-based compound according to the present invention has been shown in the description and drawings, the description and drawings above describe and show only the essential components for understanding the present invention, and are shown in the description and drawings In addition to one process and apparatus, processes and apparatus not separately described and shown may be appropriately applied and used in order to carry out the method for purifying an alcohol-based compound according to the present invention.

Hereinafter, the present invention will be described in more detail by way of Examples. However, the following examples are intended to illustrate the present invention, and it is apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention, and the scope of the present invention is not limited thereto.

< Example >

production example One

100.0 g 2-ethylhexanol (containing 700 ppm butylbutyrate) and titanium(IV) 2-ethylhexyloxide (Aldrich, 95%) in a 250 ml 2-neck round bottom flask equipped with a condenser 2.50 g was added, and the transesterification reaction was performed by heating at 130 °C. Thereafter, the reaction mixture was sampled at every predetermined reaction time, and the removal time of butyl butyrate was measured using gas chromatography. Reaction containing 2-ethylhexanol (bp. 184.7 °C), n-butanol (bp. 117.7 °C) and 2-ethylhexylbutyrate (bp. 237 °C) in a two-necked round bottom flask after butyl butyrate is removed The product was obtained.

Table 1 below shows the time (hr) at which butyl butyrate is completely removed through the transesterification reaction, and the content and removal rate of residual butyl butyrate.

production example 2

In a 250 ml 2-neck round bottom flask equipped with a condenser, 100.0 g 2-ethylhexanol (containing 10,693 ppm butylbutyrate) and titanium(IV) 2-ethylhexyloxide (Aldrich, 95%) 2.50 g was added, and the transesterification reaction was performed by heating at 140 °C. Thereafter, the reaction mixture was sampled at every predetermined reaction time, and the removal time of butyl butyrate was measured using gas chromatography. Reaction containing 2-ethylhexanol (bp. 184.7 °C), n-butanol (bp. 117.7 °C) and 2-ethylhexylbutyrate (bp. 237 °C) in a two-necked round bottom flask after butyl butyrate is removed The product was obtained.

Table 1 below shows the time (hr) at which butyl butyrate is completely removed through the transesterification reaction, and the content and removal rate of residual butyl butyrate.

production example 3

100.0 g of 2-ethylhexanol (containing 50,665 ppm butylbutyrate) and titanium(IV) 2-ethylhexyloxide (Aldrich, 95%) in a 250 ml 2-neck round bottom flask equipped with a condenser 2.50 g was added, and the transesterification reaction was performed by heating at 130 °C. After 4 hours, the reaction mixture was sampled and the removal rate of butyl butyrate was measured for 4 hours using gas chromatography. After the transesterification reaction, 2-ethylhexanol (bp. 184.7 °C), butylbutyrate (166 °C), n-butanol (bp. 117.7 °C) and 2-ethylhexylbutyrate (bp. 237 ° C.), but a reaction product containing the butyl butyrate at a concentration of 1,636 ppm was obtained.

Table 1 below shows the time (hr) at which butyl butyrate is completely removed through the transesterification reaction, and the content and removal rate of residual butyl butyrate.

Example One

The distillation process of the reaction product obtained in Preparation Example 1 was simulated using Aspen Plus simulator by Aspen.

First, 1000 kg/h of a feed stream containing the reaction product from which butylbutyrate has been removed as described above is supplied to the first distillation column to a bottom discharge stream containing 2-ethylhexanol and 2-ethylhexylbutyrate, and n - The overheads stream comprising butanol is drawn off. At this time, a portion of the top discharge stream is branched and passed through a condenser, then refluxed to the top of the first distillation column, a part of the bottom discharge stream is branched and passed through a reboiler, and then the first distillation column refluxed to the lower part of

In addition, the flow rate of the top discharge stream distilling to the top of the first distillation column was 50 kg/h, and the flow rate of the bottom discharge stream discharged to the bottom was 950 kg/h. In addition, the discharge pressure of the top discharge stream of the first distillation column was 60 torr, the discharge pressure of the bottom discharge stream was 80 torr, and the discharge temperature of the bottom discharge stream was 119.7 °C.

Table 2 below shows the content of butylbutyrate in the feed stream supplied to the first distillation column, and the content (ppm) of butylbutyrate contained in the bottom discharge stream of the first distillation column.

Example 2

The distillation process of the reaction product obtained in Preparation Example 2 was simulated using Aspen Plus simulator by Aspen. Hereinafter, the simulation process was performed in the same manner as in Example 1.

Table 2 below shows the content of butylbutyrate in the feed stream supplied to the first distillation column, and the content (ppm) of butylbutyrate contained in the bottom discharge stream of the first distillation column.

Example 3

The distillation process of the reaction product obtained in Preparation Example 1 was simulated using Aspen Plus simulator by Aspen.

First, 1000 kg/h of a feed stream containing the reaction product from which butylbutyrate has been removed as described above is supplied to the first distillation column to a bottom discharge stream containing 2-ethylhexanol and 2-ethylhexylbutyrate, and n - The overheads stream comprising butanol is drawn off. At this time, a portion of the top discharge stream is branched and passed through a condenser, then refluxed to the top of the first distillation column, a part of the bottom discharge stream is branched and passed through a reboiler, and then the first distillation column refluxed to the lower part of

In addition, the flow rate of the top discharge stream distilling to the top of the first distillation column was 50 kg/h, and the flow rate of the bottom discharge stream discharged to the bottom was 950 kg/h. In addition, the discharge pressure of the top discharge stream of the first distillation column was 60 torr, the discharge pressure of the bottom discharge stream was 80 torr, and the discharge temperature of the bottom discharge stream was 119.7 °C.

Then, the bottom draw stream of the first distillation column is fed to the second distillation column to discharge a bottom draw stream comprising 2-ethylhexyl butyrate and a top draw stream comprising 2-ethylhexanol. At this time, a portion of the top discharge stream is branched and passed through a condenser, then refluxed to the top of the second distillation column, and a portion of the bottom discharge stream is branched and passed through a reboiler, followed by a second distillation column refluxed to the lower part of

Table 2 below shows the content of butyl butyrate in the feed stream supplied to the first distillation column, and the content (ppm) of butyl butyrate contained in the top discharge stream of the second distillation column.

comparative example One

The distillation process of 2-ethylhexanol (containing 1,000 ppm of butyl butyrate) was simulated using Aspen Plus simulator from Aspen.

Specifically, 1000 kg/h of the feed stream containing the 2-ethylhexanol (containing 1,000 ppm of butyl butyrate) is supplied to the first distillation column, and the top discharge stream containing butyl butyrate and 2-ethylhexanol are A bottom draw stream comprising

At this time, a portion of the upper discharge stream is branched and passed through a condenser, then refluxed to the top of the first refinery, and a part of the lower discharge stream is branched and passed through a reboiler, after which the first It was refluxed to the bottom of the purification tower.

In addition, the flow rate of the top discharge stream distilling to the top of the first distillation column was 50 kg/h, and the flow rate of the bottom discharge stream discharged to the bottom was 950 kg/h. In addition, the discharge pressure of the top discharge stream of the first distillation column was 60 torr, the discharge pressure of the bottom discharge stream was 80 torr, and the discharge temperature of the bottom discharge stream was 119.7 °C.

Table 2 below shows the content of butylbutyrate in the feed stream supplied to the first distillation column, and the content (ppm) of butylbutyrate contained in the bottom discharge stream of the first distillation column.

Preparation Example 1 Preparation 2 Preparation 3 transesterification reaction Butyl butyrate removal time (hr) 1.0 1.0 4.0 * Residual butyl butyrate content (ppm) 0 0 1,636 *Butyl butyrate removal rate (%) 100.0 100.0 96.7

Comparative Example 1 Example 1 Example 2 Example 3 *Butylbutyrate in the feed stream
Content (ppm) 1,000 0 0 0 *Butyl butyrate
Content (ppm) 1.0 0 0 0

* Residual butyl butyrate content: Residual butyl butyrate content in the reaction product obtained after the transesterification reaction in Preparation Example

* Butyl butyrate removal rate: Removal rate of butyl butyrate removed by transesterification reaction in Preparation Example

* Butyl butyrate content in the feed stream: the content of butyl butyrate in the feed stream supplied to the first distillation column

* Butylbutyrate content: butylbutyrate content in the bottom draw stream of the first distillation column for Comparative Examples 1, 1, and 2, and butylbutyrate in the top draw stream of the second distillation column for Example 3 content of

< Experimental example >

Experimental example One

In each of Examples 1, 2, and Comparative Example 1, the reflux ratio and the tower for discharging 2-ethylhexanol of the same purity included in the bottom discharge stream of the first distillation column The amount of heat required to regenerate (Gcal/h) by number of theoretical plates is shown in FIG. 1 (Comparative Example 1: 2-EH/Butyl butyrate, Examples 1, 2: 2-EH/n-BuOH).

Referring to Table 2, after transesterification of 2-ethylhexanol containing butylbutyrate as an impurity is performed according to the method for purifying an alcohol-based compound of the present invention, a distillation process of the transesterification reaction product Compared to Comparative Examples, the Examples in which butylbutymous in the final purification target object (the bottom discharge stream of the first distillation column in Examples 1 and 2 and Comparative Example 1, and the top discharge stream of the second distillation column in Example 3) were compared to Comparative Examples It can be seen that the content of the rate is remarkably small.

In particular, referring to Table 1, the content of butyl butyrate contained in 2-ethylhexanol is 700 ppm (0.07 wt%) in Preparation Example 1, and the content of butyl butyrate contained in 2-ethylhexanol is In Preparation Example 2 of 10,693 ppm (1% by weight), all butylbutyrate was removed within a reaction time of 1 hour, so that the content of residual butylbutyrate was 0 ppm, and the amount of butylbutyrate contained in 2-ethylhexanol was Preparation Example 3 having a content of 50,665 ppm (5 wt%) showed a removal rate of 96.7% of butylbutyrate during a reaction time of 4 hours longer than the reaction time of Preparation Examples 1 and 2, and the content of residual butylbutyrate was 1,636 ppm can confirm. Accordingly, when the butylbutyrate is contained in an amount of 0.1 to 3% by weight compared to the 2-ethylhexanol, it can be confirmed that the removal rate of the butylbutyrate is 99.0% or more.

On the other hand, referring to Figure 1, in the case of Examples 1 to 2 in which the distillation process was performed after transesterification of 2-ethylhexanol containing butylbutyrate to remove butylbutyrate, the reflux ratio for each number of theoretical plates, And it can be seen that the amount of heat for reboiling by the number of theoretical plates of the tower is significantly reduced compared to Comparative Example 1.

On the other hand, in Comparative Example 1 in which the distillation process was performed without transesterification of 2-ethylhexanol containing butylbutyrate, the reflux ratio for each number of theoretical plates in the tower, and the amount of heat in the reboiler for each number of theoretical plates in the tower compared to Examples high can be seen.

That is, when transesterification of 2-ethylhexanol containing butylbutyrate is performed to remove butylbutyrate and then a distillation process is performed (Example), transesterification of 2-ethylhexanol containing butylbutyrate is performed (Example). Compared to the case of performing the distillation process without performing esterification (Comparative Example), the number of theoretical plates in the distillation column may be lowered to show a similar level of butylbutyrate removal rate and purification efficiency of 2-ethylhexanol. It can be confirmed that the cost can be reduced, and the reflux ratio can be reduced, so that the amount of heat consumed for reflux in each distillation column is significantly reduced.

Accordingly, it was confirmed that high-purity 2-ethylhexanol could be purified while reducing the energy consumed in the distillation process and the installation cost of the apparatus through the purification method of the alcohol-based compound according to the present invention.

Claims (12)

A reaction product comprising the first alcohol-based compound and the first ester-based compound is subjected to transesterification reaction to obtain a reaction product including the first alcohol-based compound, the second alcohol-based compound, and the second ester-based compound to (S10); and
supplying the reaction product to the first distillation column, and discharging a bottom discharge stream including the first alcohol-based compound and the second ester-based compound, and a top discharge stream including the second alcohol-based compound (S20) A method for purifying an alcohol-based compound. The method of claim 1,
In the reactant, the first ester-based compound is included in an amount of 0.1 to 3% by weight relative to the first alcohol-based compound. According to claim 1,
After step (S20), the bottom discharge stream of the first distillation column is supplied to the second distillation column to discharge the bottom discharge stream including the second ester-based compound and the top discharge stream including the first alcohol-based compound A method for purifying an alcohol-based compound further comprising step (S30). According to claim 1,
The difference in boiling point between the first alcohol-based compound and the first ester-based compound is,
A method of purifying an alcohol-based compound that is smaller than the difference in boiling points between the first alcohol-based compound and the second alcohol-based compound, and the difference in boiling points between the first alcohol-based compound and the second ester-based compound. According to claim 1,
The difference in boiling point between the first alcohol-based compound and the first ester-based compound is 1 to 30 °C,
The difference in the boiling points of the first alcohol-based compound and the second alcohol-based compound, and the difference in boiling points between the first alcohol-based compound and the second ester-based compound are each independently 50 to 100 °C purifying method of an alcohol-based compound. According to claim 1,
The transesterification reaction is from the group consisting of titanium(IV) n-butoxide, titanium(IV) methoxide, titanium(IV) ethoxide, titanium(IV) propoxide, and titanium(IV) isopropoxide. A method for purifying an alcohol-based compound that is carried out in the presence of one or more selected catalysts. 6. The method of claim 5,
The catalyst is a method for purifying an alcohol-based compound that is used in an amount of 0.005 to 0.01 mol relative to 1 mol of the first alcohol-based compound. 6. The method of claim 5,
The transesterification reaction is a method for purifying an alcohol-based compound is carried out at 100 to 200 ℃ for 0.5 to 10 hours. According to claim 1,
The first alcohol-based compound is 2-ethylhexanol, isopropanol, isobutanol, isononanol, sec-butanol, cyclohexanol, n-heptanol, isoheptanol, 2-octanol, cyclohexyloctanol, 1 - A method for purifying at least one alcohol-based compound selected from the group consisting of methylheptanol and 3,5,5-trimethylhexanol. According to claim 1,
The first ester-based compound is butyl butyrate, methyl burate, ethyl burate, hexyl burate, octyl burate, methyl formate, ethyl formate, propyl formate, butyl formate, methyl acetate, ethyl acetate, propyl A method for purifying at least one alcohol-based compound selected from the group consisting of acetate, butyl acetate, methyl propionate, ethyl propionate, propyl propionate and butyl propionate. According to claim 1,
The first alcohol-based compound is 2-ethylhexanol,
The first ester-based compound is butyl butyrate,
The second alcohol-based compound is n-butanol,
The second ester-based compound is a method of purifying an alcohol-based compound is 2-ethylhexyl butyrate. 12. The method of claim 11,
The transesterification reaction is a method of purifying an alcohol-based compound that is carried out in the presence of a catalyst of titanium (IV) 2-ethylhexyl oxide or titanium (IV) n-butoxide.

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