KR20150135095A

KR20150135095A - Formic Acid Separating Method and Formic Acid Separation Process System

Info

Publication number: KR20150135095A
Application number: KR1020150068004A
Authority: KR
Inventors: 정소이; 김대성; 남현; 이원재; 공명진; 하현배; 최용진
Original assignee: 주식회사 엘지화학
Priority date: 2014-05-22
Filing date: 2015-05-15
Publication date: 2015-12-02
Also published as: KR102016732B1; KR20150135029A; KR101990384B1; KR101641140B1; KR20150135096A

Abstract

The present invention relates to a formic acid separating method, and to a formic acid separation process system. The method comprises the steps of: generating a mixture by applying water and an organic extract to a liquid reaction product generated by reaction of glycerol and a formic acid; and separating an aqueous phase and an organic phase from the mixture.

Description

Technical Field [0001] The present invention relates to a method for separating formic acid from a formic acid,

The present invention relates to a method for separating formic acid and a process for separating formic acid, and more particularly, to a method for separating formic acid from glycerol and formic acid in the process of producing allyl alcohol in a liquid reaction product.

Formic acid is one of the shortest carboxylic acids represented by HCOOH and is widely used as a preservative or disinfectant or as a raw material or intermediate in the production of many compounds. In addition, it has been applied in various fields such as being used as a hydrogen storage compound for storing carbon dioxide together with hydrogen, or in recent years, as a compound that can be regenerated in a biomass pyrolysis process.

Specifically, in the dehydroxylation reaction of glycerol, formic acid can be used to produce allyl alcohol, which is an intermediate of acrylic acid. The dehydroxylation reaction proceeds in two stages. In the first stage, formic acid acts as a reactant. In the second stage, formic acid acts as a catalyst. Therefore, it requires an excess amount of formic acid to participate in the actual reaction. According to U.S. Patent No. 8273926, in order to maximize the yield of allyl alcohol, the yield of allyl alcohol was increased by adding an excess of formic acid to glycerol (e.g., 1.45 eq.). However, when an excess amount of formic acid is used, there is a large amount of unreacted formic acid that has not participated in the reaction. In fact, the reactor top product of the dehydroxylation reaction is carbon dioxide (CO ₂ ), water (H ₂ O, W, boiling point 100 ° C), allyl formate (AF, boiling point 80-83 ° C), allyl alcohol allyl alcohol, AA, boiling point 97 캜) as well as unreacted formic acid (FA, boiling point 100.8 캜). Therefore, if the unreacted formic acid at the upper part of the reactor can be recovered and reused as the reactant, the amount of formic acid added to the reactor can be reduced, and the yield can be increased in the whole process. However, the difference in boiling points of W, AA, and FA, which are the upper products of the reactor, is not large, and water-allyl alcohol (W-AA, water- formic acid, Since azeotrope of water-allyl alcohol-formic acid (W-AA-FA) is present, it is very difficult to separate formic acid from the product by a conventional distillation.

Conventionally, formic acid is separated by using a neutralizing agent such as carboxyl amide or potassium carbonate as in Patent Document No. 2002-0070350, or trialkylphosphine oxide is extracted as formic acid as a 10-0377034 Respectively. However, the method using neutralization has a problem that a large amount of wastewater is generated to cause additional costs in wastewater treatment, and that formic acid is lost due to an acid-base reaction, which is inefficient in terms of recovery. In addition, the method using the above-mentioned extracting agent requires an additional separation process for a mixture of formic acid and an extracting agent.

Korea Patent No. 10-0377034

Conventionally, formic acid was separated using a neutralizing agent or an extracting agent. However, this not only causes a large amount of wastewater to be generated, but also has a problem in that it is uneconomical in the recycling surface of formic acid.

In order to solve the problems of the prior art as described above, it is an object of the present invention to provide a method for separating unreacted formic acid contained in a product in a high purity in a process for producing allyl alcohol from glycerol.

In order to accomplish the above object, the present invention provides a method for separating unreacted formic acid from a reaction of glycerol and formic acid in an allyl alcohol production method, comprising the steps of: 1) adding water and an organic extracting agent to a liquid reaction product produced by the reaction of glycerol and formic acid To produce a mixed solution; And 2) separating an aqueous phase and an organic phase from the mixed solution, wherein the organic extractant has an E _T ^N value of 0.420 or more and 0.680 or less by using the following equation (1).

[Equation 1]

E _T (solvent), E _T (TMS) and E _T (water) in Equation 1 represent the molar transition energy of the solvent, tetramethylsilane and water to be used, respectively.

According to a preferred embodiment of the present invention, the organic extractant may include at least one selected from hydrocarbon rings having 4 to 10 carbon atoms or alcohols having a chain, and most preferably, the organic extractant is 1- Octanol, n-butanol, ortho-tert-butyl phenol and 2-ethylhexanol. The mass ratio of the water phase to the organic phase may be 1:20 to 20: 1.

According to a preferred embodiment of the present invention, the liquid reaction product of step 1) may include: a) introducing formic acid into glycerol, firstly reacting in an inert gas atmosphere, And b) separating the liquid reaction product containing allyl alcohol from the gaseous reaction product generated in the step a) through a condensation process. The gas phase reaction product may include at least one member selected from the group consisting of carbon dioxide, water vapor, allyl formate, allyl alcohol and unreacted formic acid. In addition, the liquid reaction product may include at least one member selected from the group consisting of allyl alcohol, allyl formate, unreacted formic acid, and water.

According to the method of separating the unreacted formic acid contained in the product in the step of producing allyl alcohol from the glycerol of the present invention, unreacted formic acid can be reused in a simple manner and the amount of formic acid used as a catalyst and reactant can be reduced, The economical efficiency in the process can be improved.

1 is a schematic diagram showing a formic acid separation process system according to a preferred embodiment of the present invention.

Hereinafter, the present invention will be described in detail. The following detailed description is merely an example of the present invention, and therefore, the present invention is not limited thereto.

Conventionally, in the step of producing allyl alcohol from glycerol, the unreacted formic acid contained in the product was separated using a neutralizing agent or an extracting agent. However, this not only causes a large amount of wastewater to be generated, but also has a problem in that it is uneconomical in the recycling surface of formic acid.

Therefore, the inventors of the present invention have found that the use of a specific organic extractant in the method of producing allyl alcohol enables efficient separation of unreacted formic acid. Thus, the present invention has been completed.

That is, the present invention relates to a method for separating unreacted formic acid from the reaction of glycerol and formic acid from the reaction of glycerol and formic acid, which comprises: 1) adding water and an organic extractant to a liquid reaction product produced by the reaction of glycerol and formic acid, ; And 2) separating the aqueous phase and the organic phase containing formic acid in said mixed solution; include, and to is the organic extraction agent is at least the E _T ^N value by using the equation (1) 0.420, 0.680 or less the group consisting of zero organic extract , And a method for separating formic acid.

[Equation 1]

According to another preferred embodiment of the present invention, the organic extractant includes at least one selected from a hydrocarbon ring having 4 to 10 carbon atoms or an alcohol having a chain. The organic extractant may preferably include at least one selected from 1-octanol, n-butanol, ortho-tert-butyl phenol and 2-ethylhexanol, and most preferably 1-octanol have.

In the above production method of allyl alcohol, as long as the glycerol can be used for the production of allyl alcohol, any commercially available product can be used without particular limitation, and preferably glycerol having a purity of 60 to 99.5% can be used. If formic acid is used in the glycerol reaction, it can be used without any particular limitation.

Hereinafter, the method for separating formic acid of the present invention will be described.

First, step 1) will be described.

In this step, water and an organic extractant are added to the liquid reaction product produced in the allyl alcohol production process.

According to a preferred embodiment of the present invention, the liquid reaction product of step 1) may include: a) introducing formic acid into glycerol, firstly reacting in an inert gas atmosphere, And b) separating the liquid reaction product containing allyl alcohol from the gaseous reaction product generated in the step a) through a condensation process.

In step a), allyl alcohol can be prepared from glycerol in a two-step reaction. According to a preferred embodiment of the present invention, the first reaction of step a) is carried out at 0 to 100 ° C, and the second reaction is carried out at 220 to 240 ° C. That is, the reaction in the second step is a reaction in which 1 mole of allyl alcohol is produced by sequentially removing 2 moles of water and 1 mole of carbon dioxide (CO ₂ ) from 1 mole of glycerol. Specifically, in the first reaction step, 1 mole of formic acid is reacted with 1 mole of glycerol under a low-temperature and inert gas atmosphere to remove one mole of water, and glycerol formate, which is a precursor of allyl alcohol, is produced. Subsequently, allyl alcohol is produced by removing 1 mole of water and 1 mole of carbon dioxide from the glycerol formate in the presence of formic acid at a high temperature through the second reaction step. In the second reaction, formic acid acts as a catalyst, not as a reactant. The inert gas may be any one selected from the group consisting of nitrogen, argon, and helium, and may be used for both the first reaction and the second reaction.

According to a preferred embodiment of the present invention, in the method for producing allyl alcohol, the reaction between glycerol and formic acid is carried out at a rate of 2.0 ° C / min or more so as to reach a reaction temperature of 220 to 240 ° C from room temperature have. If the reaction temperature is lower than 220 ° C., the reaction does not proceed to the next step in the intermediate glyceryl formate. If the reaction temperature is higher than 240 ° C., allylformate formation is increased. The rate of temperature rise from the room temperature after the addition of formic acid to the glycerol in the step a) is preferably 2.0 ° C / min or more, more preferably 2.0 to 7.0 ° C / min, more preferably 4.0 to 7.0 ° C / min desirable. When the rate of temperature rise is less than 2.0 DEG C / min, the production of glyceryl diformate is dominant in the one-step reaction, and the amount of allyl formate is increased in the two-step reaction. When the total reaction time is more than 7 hours, the content of allyl alcohol in the liquid reaction product sample may be lowered, . The gas phase reaction product generated in step a) may include at least one selected from the group consisting of carbon dioxide, water vapor, allyl formate, allyl alcohol and unreacted formic acid.

In the step b), the liquid reaction product may be separated in any manner as long as it is generally usable, and preferably a gas separator may be used. The liquid reaction product separated in step b) may include at least one member selected from the group consisting of allyl alcohol, allyl formate, unreacted formic acid, and water.

The reaction products such as allyl formate and allyl alcohol contained in the liquid reaction product obtained as described above have a very high partition coefficient for a specific organic extractant. Formic acid, on the other hand, has a low partition coefficient. Thus, in this step, water and a particular organic extractant are added to the liquid reaction product to allow for the separation of formic acid from the liquid reaction product.

According to one preferred embodiment of the invention, the particular choice of organic extractant in the can, based on the E ^N _T value indicates the polarity of the solvent, and the E _T ^N has to be defined by the equation (1).

[Equation 1]

The value E _T (solvent) through the equation E 1 _T (TMS), and converts the E _T (solvent) value to a value between a standard by E _T (water) 0 and 1. Set the water _T E ^N value to 1, more by setting the E ^N _T value of TMS to 0. The greater the value of E _T ^N large polarity, smaller the value of ^N _T E relativization thereby the difference in polarity to be small polarity.

Specifically, E ^N _T value indicates the polarity of each component constituting the liquid reaction product is as follows. E _T ^N value of the water (W) is 1.000, E _T ^N value of formic acid (FA) is E _T ^N value of 0.728, allyl alcohol (AA) is E _T ^N value of 0.660, and allyl formate (AF) is About 0.440. Therefore, when an organic extractant having polarity similar to that of allyl alcohol and allyl formate is used, only formic acid having high affinity with water can be separated into an aqueous layer.

For example, in the separation of formic acid, the selection of the organic extractant may include at least one selected from the group consisting of organic extractants having an E _T ^N value of 0.420 or more and 0.680 or less by using Equation (1). If the E _T ^N value is less than 0.420, the affinity with allyl alcohol is lowered, so that only formic acid is difficult to be extracted into the water layer. If the E _T ^N value exceeds 0.680, the affinity between formic acid and the organic extracting agent is increased. There may be a problem.

The method of adding the organic extractant to the liquid reaction product as described above can be used in any manner without any particular limitation. Preferably, in the case of two or more stages of multi-stage extraction, it may be carried out by one or more methods selected from cross current, counter current and co-current.

Next, step 2) will be described.

In this step, the mixed solution produced in the step 1) may be separated into an aqueous phase and an organic phase. The separation can be carried out by any method which can be generally used, but preferably by an extraction method. More specifically, allyl formate and allyl alcohol can be extracted in the organic phase, and formic acid can be extracted in the aqueous phase in a high purity through multi-stage extraction.

According to a preferred embodiment of the present invention, the mass ratio of the water phase to the organic phase may be 1:20 to 20: 1, and preferably 1: 5 to 5: 1.

Water may be from 30 to 99 wt%, preferably from 60 to 90 wt%, based on the total weight percentage of the water phase. If the amount of water is less than 30% by weight, the layer may not be separated during extraction or take too long. If the amount of water is more than 99% by weight, an additional water removal process may be required, which may result in poor economical efficiency. The remaining amount of the water phase may be formic acid. Therefore, the aqueous phase can be obtained only formic acid in a conventionally usable manner.

According to a preferred embodiment of the present invention, the organic extractant remaining in the organic phase separated in the step 2) may be recovered. For example, when the organic phase is added to the distillation column, the organic extractant can be recovered from the column and the effluent containing allyl alcohol can be recovered on the column.

Consequently, in the present invention, formic acid can be obtained from the separated water phase by separating the liquid reaction product into water phase and organic phase using a specific organic extractant and water.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the embodiments of the present invention described below are illustrative only and the scope of the present invention is not limited to these embodiments. The scope of the present invention is indicated in the claims, and moreover, includes all changes within the meaning and range of equivalency of the claims. In the following Examples and Comparative Examples, "%" and "part" representing the content are based on weight unless otherwise specified.

Manufacturing example : Obtain a liquid reaction product

A thermometer was installed on the first neck of the 3-neck round bottom flask to measure the reactor internal temperature. The second sphere of a 3-neck round bottom flask was connected to a gas separator separator connected to a 1-neck round bottom flask. Then, glycerol and formic acid were added at a molar ratio of 1: 1.45 to a third sphere of a 3-neck round bottom flask. Thereafter, the reaction was heated up to 230? At a rate of 4.2? / Min in a sand bath under a nitrogen atmosphere. At this time, as the reaction proceeded, a gaseous reaction product was generated from the liquid reaction product, which was passed through a gas separator connected to the reactor, and only a liquid reaction product was obtained in a 1-neck round bottom flask installed at the end of the gas separator. After the reaction was completed, the 3-neck round bottom flask reactor was cooled and the liquid reaction product collected in a 1-neck round bottom flask was analyzed by gas chromatography (GC) and high performance liquid chromatography HPLC) analysis, and the composition is shown in Table 1. < tb > < TABLE >

matter Allyl alcohol Formic acid water Allyl formate Ratio in liquid reaction product (wt%) 37.7 24.8 23.4 14.1

Example 1: 1- Octanol Extraction using

10 g of the liquid reaction product obtained in the above Production Example was placed in a 250 ml Erlenmeyer flask, and water corresponding to 12.8 times the weight of allyl formate was added thereto to prepare an aqueous solution. 5 g of the aqueous solution was taken and 1-octanol was added as an extractant in the same amount as the aqueous solution.

Then, it was agitated with a vortex mixer for 1 minute and allowed to stand for 1 hour. Then, the weight of each layer was measured after confirming that the layer separation occurred between the organic phase and the water phase. The components contained in each phase were quantified by gas chromatography (GC) and high performance liquid chromatography (HPLC) on the separated organic phase and water phase. Based on the quantified data, the distribution coefficient of each substance was calculated using the following equation (2). The calculated values are shown in Table 2.

&Quot; (2) "

Example 2

The procedure of Example 1 was repeated except that n-butanol was used as an organic extracting agent. The calculated values are shown in Table 2.

Example 3

The procedure of Example 1 was repeated except that ortho-tertiary butylphenol was used as the organic extractant as the extracting agent. The calculated values are shown in Table 2.

Comparative Example One

The procedure of Example 1 was repeated, except that ethyl acetate was used as the organic extractant. The calculated values are shown in Table 2.

Comparative Example 2

The procedure of Example 1 was repeated, except that methyl isobutyl ketone was used as an organic extracting agent. The calculated values are shown in Table 2.

Comparative Example 3

The procedure of Example 1 was repeated, except that methyl alcohol was used as the organic extractant. The calculated values are shown in Table 2.

Organic extractant E _T ^N Material partition coefficient Formic acid Allyl alcohol Allyl formate Example 1 0.543 0.341 1.866 9.812 Example 2 0.602 0.288 4.216 19.973 Example 3 0.565 0.285 5.400 14.704 Comparative Example 1 0.228 No layer separation Comparative Example 2 0.269 No layer separation Comparative Example 3 0.762 No layer separation

As can be seen from Table 2, Examples 1 to 3 were separated, and allyl alcohol and allyl formate had high concentrations in the organic phase and formic acid had a high concentration in the aqueous phase.

However, it was not observed that all of the comparative examples 1 to 3 were layer-separated.

Experimental Example

Using Aspen using the partition coefficient obtained in Example 1, the process simulation as shown in Fig. 1 was carried out. For the multi-stage extraction tower with 30 stages in total, the water content was 5.715 Kg / h in the first stage (Stream 1), 8.990 Kg / h in 1-octanol at 30 stages (Stream 3) Model solution was injected at 3.507 Kg / h, respectively. The 1-octanol was added in countercurrent.

The mass fractions of the organic phase (stream 4) and water phase (stream 5) obtained after the extraction were analyzed, and the results are shown in Table 3. Flow 1 in FIG. 1 is the flow of injected water (H ₂ O), flow 2 is the flow of the liquid reaction product produced in the preparation example, and flow 3 is the flow of the organic extractant being injected. And stream 4 is the separated organic phase stream after extraction and stream 5 is the separated aqueous phase stream after extraction.

Material name Flow 1 Flow 2 Flow 3 Flow 4 Flow 5 Allyl formate 0.000 0.129 0.000 0.040 0.000 Allyl alcohol 0.000 0.347 0.000 0.107 0.001 water 1,000 0.296 0.000 0.060 0.883 Formic acid 0.000 0.228 0.000 0.000 0.116 1-octanol 0.000 0.000 1,000 0.793 0.000

As shown in Table 3, the main components of the water phase (stream 5) were water and formic acid, and the major components of the organic phase (stream 4) were 1-octanol, allyl alcohol and allyl formate.

1: flow 1, 2: flow 2, 3: flow 3, 4: flow 4, 5: flow 5

Claims

As a method for separating unreacted formic acid from the reaction of glycerol and formic acid in the method for producing allyl alcohol,
1) adding a water and an organic extractant to a liquid reaction product produced by the reaction of glycerol and formic acid to produce a mixture; And
2) separating the aqueous phase and the organic phase in the mixed solution,
Wherein the organic extractant has an E _T ^N value of 0.420 or more and 0.680 or less in formula (1);
[Equation 1]

In the above formula (1), E _T (solvent), E _T (TMS) and E _T (water) are the molar transition energy of the organic extractant, tetramethylsilane and water, respectively.

The method according to claim 1,
Wherein the organic extracting agent comprises at least one selected from hydrocarbon rings having 4 to 10 carbon atoms or alcohols having a chain.

The method according to claim 1,
Wherein the organic extractant comprises at least one selected from the group consisting of 1-octanol, n-butanol, ortho-tert-butyl phenol and 2-ethylhexanol.

The method according to claim 1,
The mass ratio of the water phase to the organic phase is from 1:20 to 20: 1 &Lt; / RTI >

The method according to claim 1,
The water in the total weight percentage of the water phase is 30 to 99 wt% Characterized in that the formic acid is separated.

The method according to claim 1,
The liquid phase reaction product of step 1)
a) adding formic acid to glycerol, first reacting in an inert gas atmosphere, and then raising the temperature to effect a second reaction; And
and b) separating the liquid reaction product containing allyl alcohol from the gaseous reaction product generated in step a) through condensation.

The method of claim 6,
Wherein the first reaction of step a) is carried out at 0 to 100 ° C, and the second reaction is carried out at 220 to 240 ° C.

The method of claim 6,
Wherein the heating rate in step a) is 2.0 to 7.0 DEG C / min.

The method of claim 6,
Wherein the inert gas is any one selected from the group consisting of nitrogen, argon and helium.

The method of claim 6,
Wherein the gas phase reaction product comprises at least one selected from the group consisting of carbon dioxide, water vapor, allyl formate, allyl alcohol and unreacted formic acid.

The method of claim 6,
Wherein the liquid reaction product comprises at least one member selected from the group consisting of allyl alcohol, allyl formate, unreacted formic acid, and water.

A formic acid separation process system to which the separation process of claim 1 is applied.