KR101556340B1 - Method for hydrogenation of phthalate compound - Google Patents

Abstract

The present invention relates to a process for the hydrogenation of phthalate compounds. According to the hydrogenation process of the present invention, the activity of the catalyst used for the reaction is maintained for a long period of time and the performance of the catalyst is increased, thereby improving the stability and economical efficiency of the hydrogenation process. Therefore, the total amount of the catalyst required for the reaction can be reduced and the replacement period can be extended, which can improve the operation stability of the process and the economical efficiency in the process operation in a commercial scale.

Description

[0001] METHOD FOR HYDROGENATION OF PHTHALATE COMPOUND [0002]

The present invention relates to a process for hydrogenating a phthalate compound, and more particularly, to a process for hydrogenating a phthalate compound capable of improving the performance and lifetime of a catalyst used in a hydrogenation process.

Phthalate-based compounds are widely used as plastics, especially as plasticizers for polyvinyl chloride (PVC). For example, electric and electronic products, medicines, paint pigments, lubricants, binders, surfactants, adhesives, tiles, food containers, packaging materials and the like.

However, as several phthalate compounds are known to cause environmental pollution and problems with endocrine disruption in humans, efforts to reduce their use have been strengthened in advanced countries such as Europe and the United States. Some products such as di (2-ethylhexyl) phthalate (DEHP), butyl benzyl phthalate (BBP) and di-n-butyl phthalate (DBP) among the phthalate plasticizers have socially an endocrine system As endocrine disrupters, environmental hormones are suspected and there is a movement to regulate them.

Accordingly, efforts have been made to develop environmentally friendly plasticizers which are equivalent to conventional plasticizers and free from environmental hormone controversy. One of them is a method of using a hydrogenation compound which is a benzene ring contained in a phthalate compound have.

A hydrogenation reaction of an aromatic compound such as a benzene ring is known to use a catalyst containing a transition metal such as ruthenium as an active component in a support.

However, since the catalytic activity of the transition metal is drastically reduced as the reaction progresses, the yield is lowered. Therefore, maintenance of catalytic activity is a very important problem in terms of commercial activity. Reduction of the catalytic activity is caused by various physical and chemical influences on the catalyst, such as blockage of catalytically active sites or loss of catalytically active sites as a result of thermal, mechanical or chemical treatment. For example, catalyst deactivation or aging is generally caused by sintering of the catalytically active sites, loss of metal as a result of deposits, or poisoning of the active sites, and a variety of mechanisms exist. Such replacement and regeneration processes due to reduced activity of the catalyst lead to product production costs.

Accordingly, in order to produce a substance usable as an environmentally friendly plasticizer on a commercial scale, there is a demand for improving the performance of the catalyst used in the hydrogenation reaction and maintaining the activity thereof, thereby increasing the life time of the catalyst.

It is an object of the present invention to improve the performance of the catalyst used for the hydrogenation reaction of the phthalate compound and to prolong the lifetime of the catalyst by maintaining the activity thereof, To a hydrogenation process.

Thus, according to one aspect of the present invention, there is provided a hydrogenation method comprising reacting a phthalate compound with hydrogen in the presence of a hydrogenation catalyst and an alcohol having 2 or more carbon atoms.

According to the hydrogenation process of the present invention, the activity of the catalyst used in the reaction is maintained for a long period of time and the performance of the catalyst is enhanced, thereby improving the stability and economical efficiency of the hydrogenation process.

In addition, it is possible to suppress the generation of high temperature due to the reaction heat in the reactor in which the hydrogenation reaction proceeds, to lower the viscosity of the reaction raw material to suppress stagnation of the flow of the liquid phase and to form a thin liquid- , The reactivity can be improved.

In addition, the lifetime of the catalyst can be prolonged by suppressing physical and chemical adsorption of metal ions, metal salt compounds or other impurity components contained in the raw phthalate compound to the catalyst.

Therefore, the total amount of catalyst required for the reaction can be reduced and the replacement period can be extended, so that the operation stability of the process and the economical efficiency in the process operation in commercial scale can be improved.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic view showing a hydrogenation reactor used in the hydrogenation process of the present invention. FIG.
2 and 3 are the results of NMR (Nuclear Magnetic Resonance) analysis of components adsorbed on the catalyst surface after the hydrogenation reaction according to Comparative Example 1.

The present invention is capable of various modifications and may have various embodiments, and specific embodiments are illustrated and described in detail. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Furthermore, terms including an ordinal number such as first, second, etc. to be used below can be used to describe various elements, but the constituent elements are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Hereinafter, a method of hydrogenating a phthalate compound of the present invention will be described in detail with reference to the drawings.

The hydrogenation process of the present invention comprises reacting a phthalate compound with hydrogen in the presence of a hydrogenation catalyst and an alcohol having 2 or more carbon atoms.

The reaction object of the hydrogenation process of the present invention is a phthalate compound, and hydrogen is added to the benzene ring of the phthalate compound by hydrogenation to convert it into the corresponding cyclohexane dicarboxylate compound.

The phthalate compound may be at least one selected from the group consisting of phthalate, terephthalate, isophthalate and the corresponding carboxylic acid.

First, the phthalate compound may be represented by the following formula (1).

[Chemical Formula 1]

In Formula 1, R 1 and R 1 'are independently the same or different and each represents a hydrogen atom, a C 1-20, preferably a C 4-20, more preferably a C 5-20, more preferably a C 5-10 Of straight or branched chain alkyl groups.

Specific examples of the phthalate compound include dibutyl phthalate (DBP), dihexyl phthalate (DHP), dioctyl phthalate (DOP), di-n-octyl phthalate (DnOP) octyl phthalate, diisononyl phthalate, diisodecyl phthalate (DIDP), and the like, but the present invention is not limited thereto. These compounds may be used alone or in combination.

The terephthalate compound may be represented by the following general formula (2).

(2)

In the above formula (2), R 2 and R 2 'are each independently the same or different and represent hydrogen, a C 1-20, preferably C 4-20, more preferably C 5-20, more preferably C 5-10 Of straight or branched chain alkyl groups.

Specific examples of the terephthalate compound include dibutyl terephthalate (DBTP), dioctyl terephthalate (DOTP), diisononyl terephthalate (DINTP), or diisodecyl terephthalate (DIDTP ; diisodecyl terephthalate), but are not limited thereto. These compounds may be used alone or in combination.

The isophthalate compound may be represented by the following general formula (3).

(3)

In the above formula (3), R3 and R3 'are each independently the same or different and represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, preferably 4 to 20 carbon atoms, more preferably 5 to 20 carbon atoms, Of straight or branched chain alkyl groups.

Specific examples of the isophthalate compound include dibutyl isophthalalate (DBIP), dioctyl isophthalate (DOIP), diisononyl isophthalate (DINIP), and diisodecyl isophthalate (DIDIP ; diisodecyl isophthalate), but are not limited thereto. These compounds may be used alone or in combination.

Preferably, dioctyl terephthalate (DOTP) may be used as the phthalate compound.

The purity of the phthalate compound may be about 98% or more, preferably about 99% or more, but is not limited thereto and phthalate compounds of any quality and purity commercially available can be used.

The phthalate compound may be obtained by esterifying an acid such as phthalic acid, terephthalic acid, or isophthalic acid or an anhydride thereof with an alcohol. After the esterification reaction, a catalyst such as sodium carbonate (Na ₂ CO ₃ ), sodium hydroxide (NaOH), calcium carbonate (CaCO ₃ ), sodium hydroxide (KOH) or the like is added to neutralize the catalyst used in the esterification reaction and the residual acid component Basic compounds are used. Accordingly, impurities such as metal ions such as Na ⁺ , K ⁺ , and Ca ^{2 +} released from such basic compounds, metal salt compounds formed by binding with the metal ions, or other reaction byproducts remain in the phthalate compound in a trace amount .

Such a small amount of the metal ion or the metal salt compound does not greatly affect the quality of the phthalate compound. However, the hydrogenation catalyst used in the hydrogenation reaction of the phthalate compound acts as a catalyst poison, do. More specifically, the metal ion or the metal salt compound is not sufficiently dissolved or dispersed and has a property of being physically or chemically adsorbed on the hydrogenation catalyst, whereby the activity of the catalyst is drastically reduced.

However, according to the hydrogenation method of the present invention, an alcohol having two or more carbon atoms effectively dissolves the metal ion, the metal salt compound or other impurity components to prevent the adsorption to the hydrogenation catalyst, thereby maintaining the activity of the hydrogenation catalyst have.

The alcohol may be an alcohol having 2 or more carbon atoms, for example, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, pentanol, hexanol, heptanol N-octanol, 2-ethylhexanol, nonanol, decanol, undecanol, dodecanol, and the like, or a mixture thereof.

The usable alcohol may be selected depending on the specific kind of the phthalate compound to be reacted. For example, when a hydrogenation reaction is carried out on dioctyl terephthalate, the use of an alcohol having 2 to 8 carbon atoms such as ethanol, butanol or octanol in the alcohol may improve the reactivity and extend the lifetime of the catalyst .

According to the present invention, the alcohol is mixed with the phthalate compound to lower the viscosity of the mixture in a liquid phase before being fed to the reactor, thereby improving the flow of the mixture in a liquid state. In addition, it absorbs the reaction heat during the hydrogenation reaction of the phthalate compound injected into the reactor, thereby suppressing the generation of high temperature due to the reaction heat. In addition, by forming a thin film on the surface of the hydrogenation catalyst, it is possible to improve the reactivity of the catalyst and suppress physical and chemical adsorption of metal ions, metal salt compounds or other impurity components contained in the raw material phthalate compound to the catalyst, The life span can be prolonged.

The alcohol is used in an amount of about 5 to about 60 parts by weight, preferably about 10 to about 50 parts by weight, more preferably about 10 to about 40 parts by weight, more preferably about 10 To 30 parts by weight. When the amount of the alcohol is less than 5 parts by weight, the effect of improving the catalyst performance is hardly exhibited. When the amount of the alcohol is more than 60 parts by weight, it is necessary to increase the reactor size, Can be lowered.

According to an embodiment of the present invention, in addition to the alcohol, a cyclohexanedicarboxylate compound, which is a reaction product of the hydrogenation reaction, may be further mixed to conduct the hydrogenation reaction. When the reaction product is further mixed by the reaction as described above, the intense reaction in the reactor can be suppressed, and the phenomenon of the reaction temperature control and local catalyst degradation on the catalyst can be reduced.

The hydrogenation process of the phthalate compound may be carried out in a liquid phase or a gas phase. According to an embodiment of the present invention, the phthalate compound and the alcohol may be in a liquid state, and hydrogen may be hydrogenated in a gaseous state.

The phthalate compound and the alcohol may be further mixed to have a uniform concentration before being added to the reactor.

According to one embodiment of the present invention, the phthalate compound and the alcohol may be mixed before being added to the reactor, and the mixture containing the phthalate compound and the alcohol may be step-up and heated to be introduced into the reactor.

More specifically, the step of raising and lowering the mixture comprising the phthalate compound and the alcohol may be carried out simultaneously or sequentially, and the desired pressure and temperature may be reached by raising and raising the temperature several times in one or more steps It is possible. For example, the pressure of the mixture containing the phthalate compound and alcohol can be increased first, and the temperature of the mixture can be raised to the liquid phase having an appropriate viscosity. According to one embodiment of the present invention, the viscosity of the mixture can range from about 0.5 to about 20.0 cps in the range of pressure and temperature conditions when entering the reactor. When the viscosity of the mixture is within the above range, it can exhibit proper flow and reactivity in the reactor.

The target pressure to be boosted to enter the reactor may be from about 50 to about 500 bar, preferably from about 100 to about 300 bar. If the pressure is less than 50 bar, the reactivity is lowered, and it is difficult to obtain a desired level of conversion. If the pressure is excessively higher than 500 bar, the reactor may be difficult to manufacture or the manufacturing cost may be greatly increased.

Further, the target temperature for raising the temperature to be introduced into the reactor may be in the range of about 50 to about 500 캜, preferably about 100 to about 300 캜. If the temperature is lower than 50 캜, the catalyst becomes inactive due to the low temperature, the flow of the mixture in the reactor is deteriorated due to the high viscosity of the mixture, and the hydrogen permeability to the phthalate compound and alcohol in the liquid phase is lowered, If the temperature is higher than 500 ° C, the reaction product is decomposed to a large extent, which makes it difficult to produce the reactor, and rapid reaction may cause difficulty in heat removal.

The mixture containing the phthalate compound and the alcohol which have been raised and raised by the above-mentioned process is introduced into the reactor filled with the hydrogenation catalyst. In addition, hydrogen (H ₂ ) in gaseous state flows into the reactor through a separate feed line, and a hydrogenation reaction is performed.

The pressure and temperature conditions of the hydrogen are the same as the temperature and pressure conditions of the mixture comprising the phthalate compound and the alcohol, at a pressure of about 50 to about 500 bar, preferably about 100 to about 300 bar, 500 < 0 > C, preferably about 100 to about 300 < 0 > C.

The hydrogenation catalyst may contain a transition metal of Group 8 as an active component and is preferably one selected from the group consisting of ruthenium (Ru), nickel (Ni), palladium (Pd), rhodium (Rh) Or more.

By this hydrogenation reaction, the aromatic ring of the phthalate compound is hydrogenated and converted into the corresponding cyclohexanedicarboxylate compound.

The reactor is not particularly limited as long as it can be used in the technical field to which the present invention belongs, and either a batch reactor or a continuous reactor can be used. In addition, the reactor may include an exothermic apparatus for releasing heat generated during the reaction.

After completion of the reaction, the resulting liquid hydrogenation product and unreacted gaseous raw material are separated. The separated gaseous feed can be recycled to the hydrogenation process. The recovered hydrogenation product can be finally separated by decompression and cooling.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing an example of a hydrogenation reactor used in the hydrogenation process of the present invention. FIG.

1, the hydrogenation apparatus comprises a liquid raw material mixer 1, a catalytic reactor 2, a gas-liquid separator 3, a depressurizing device 4, a heat exchanger 5, and a separator 6 .

The phthalate compound (10) and the alcohol (20) are mixed uniformly in the liquid raw material mixer (1). The mixed liquid raw material 40 is heated and raised and supplied to the catalytic reactor 2 at appropriate temperature and pressure. In addition, the hydrogen 30 is also heated and raised, and the hydrogen raw material in the gaseous state is transferred to the upper end of the catalytic reactor 2, and the hydrogenation reaction proceeds.

The reaction mixture 50 from the catalytic reactor 2 is transferred to the gas-liquid separator 3 and the liquid reaction product 60 is transferred to the depressurization device 4 by the gas-liquid separator 3, (70) is circulated for discharge or reuse. The liquid reaction product 80, which has been decompressed via the pressure control device 4, is cooled through the heat exchanger 5. The cooled reaction product 90 is finally subjected to further purification through a separation device 6 to remove the impurity 100 to obtain the final reaction product 110.

1, since the position of each device can be changed and other devices not shown in FIG. 1 can be included if necessary, the hydrogenation method of the present invention is limited to the apparatus and process sequence shown in FIG. 1 no. For example, the pelletizing device 4 may be placed in front of the gas-liquid separator 3.

According to the above-described hydrogenation method of the present invention, the hydrogenation conversion rate of the phthalate compound can be improved by about 10% or more, preferably about 20% or more, as compared with the case where the hydrogenation reaction is carried out without the alcohol. Further, even after the reaction proceeds, a high hydrogenation reaction conversion rate can be maintained and the catalyst life can be improved.

Best Mode for Carrying Out the Invention Hereinafter, the function and effect of the present invention will be described in more detail through specific examples of the present invention. It is to be understood, however, that these embodiments are merely illustrative of the invention and are not intended to limit the scope of the invention.

< Example >

Example  One

20 parts by weight of octanol was mixed with 100 parts by weight of dioctyl terephthalate (DOTP) having a purity of 99%, and then injected into a catalytic reactor through a pump. Preheated to a pressure of 150 bar and a temperature of 120 ° C, and hydrogen (H ₂ ) was also preheated to the same pressure and temperature, and then fed to the top of the reactor.

The reactor was a single tube. In the outer jacket, the heat generated in the reactor was removed through hot oil, and the hydrogenation reaction was performed while maintaining the temperature.

The catalyst used in the reactor was a ruthenium (Ru) catalyst, having a cylinder size of 3.2 mm in diameter and 3 mm in height.

Example  2

In Example 1, hydrogenation was carried out in the same manner as in Example 1, except that 20 parts by weight of butanol (n-butanol) was used instead of octanol.

Example  3

In Example 1, hydrogenation was carried out in the same manner as in Example 1 except that 20 parts by weight of ethanol was used instead of octanol.

Example  4

20 parts by weight of octanol was mixed with 100 parts by weight of dioctyl terephthalate, and the batch catalyst reactor was charged with hydrogen and continuously supplied with 1 NLPM (Normal Liter Per Minute) for 2 hours. At this time, mixing was continuously carried out through a stirrer inside the reactor, and the reaction pressure and the reaction temperature were maintained at 150 bar and 140 ° C., respectively.

The reactor was a single tube. In the outer jacket, the heat generated in the reactor was removed through hot oil, and the hydrogenation reaction was performed while maintaining the temperature.

The catalyst used in the reactor was a ruthenium (Ru) catalyst, having a cylinder size of 3.2 mm in diameter and 3 mm in height.

Comparative Example  One

In Example 1, the hydrogenation reaction was carried out in the same manner as in Example 1, except that the alcohols were not mixed.

Comparative Example  2

In Example 1, hydrogenation was carried out in the same manner as in Example 1, except that 20 parts by weight of methanol was used instead of octanol.

Comparative Example  3

In Example 4, hydrogenation was carried out in the same manner as in Example 1, except that the alcohols were not mixed.

The reaction conditions of Examples 1 to 4 and Comparative Examples 1 to 3 are summarized as shown in Table 1 below.

Reactor type Alcohol type and content Example 1 Continuous 20 parts by weight of octanol Example 2 Continuous Butanol 20 parts by weight Example 3 Continuous Ethanol 20 parts by weight Example 4 Batch 20 parts by weight of octanol Comparative Example 1 Continuous Without Comparative Example 2 Continuous Methanol 20 parts by weight Comparative Example 3 Batch Without

< Experimental Example >

Evaluation of catalyst performance

The catalyst performance of the above Examples and Comparative Examples was evaluated by the following method.

Initial performance: Hydrogenation was carried out using a catalyst which had not been used before, and di (2-ethylhexyl) cyclohexane-1,4-dicarboxylate di (2 -ethylhexyl) cyclohexane-1,4-dicarboxylate, DEHCH) was calculated.

Relative initial performance: Relative value of the initial performance of each example when the initial performance of the hydrogenation reaction proceeded without containing alcohol was set to 1 was calculated.

DOTP 100 kg Performance after reaction: After performing a hydrogenation reaction on 100 kg of DOTP, the ratio of the weight portion converted to di (2-ethylhexyl) cyclohexane-1,4-dicarboxylate relative to 100 parts by weight of the charged DOTP (%) Was calculated.

Relative performance after DOTP 100 kg reaction : Relative value of performance after 100 kg of DOTP reaction of each example was calculated when hydrogenation reaction performance was 1 after 100 kg of DOTP without alcohol.

Catalyst lifetime: 100 kg The reaction was calculated by dividing the relative performance by the relative performance of the initial reaction.

Initial Performance
(unit: %) Relative performance Performance after DOTP 100kg reaction
(unit: %) Relative performance after 100kg reaction Catalyst life Example 1 44.2 1.300 30.2 3.545 2.727 Example 2 41.5 1.220 21.80 2.559 2.097 Example 3 43.5 1.279 30.90 3.627 2.835 Comparative Example 1 34.0 1,000 8.52 1,000 1,000 Comparative Example 2 5.6 0.165 2.30 0.270 1.639

Initial Performance
(unit: %) Relative performance Performance after DOTP 100kg reaction
(unit: %) Relative performance after 100kg reaction Catalyst life Example 4 54.2 1.215 48.7 1.330 1.094 Comparative Example 3 44.6 1,000 36.6 1,000 1,000

In Table 2 and 3, it can be seen that, in the case of an example in which the hydrogenation reaction was carried out by mixing an alcohol having 2 or more carbon atoms, the conversion rate was increased to at least 20% Able to know. In addition, the hydrogenation method according to the present invention exhibits a still higher relative conversion ratio than the comparative example, even when the conversion rate according to the progress of the reaction is observed, and the catalyst life is also increased.

However, in Comparative Example 2 in which methanol was mixed, the relative performance was lower than that in Comparative Example 1 in which no alcohol was mixed, showing no improvement in catalytic performance.

FIG. 2 shows the result of NMR (Nuclear Magnetic Resonance) analysis of the component adsorbed on the catalyst surface after the hydrogenation reaction according to Comparative Example 1, and FIG. 3 shows the NMR graph of FIG. 2 in an enlarged manner.

2 and 3, it can be seen that the Na salt compound of terephthalic acid is adsorbed on the surface of the catalyst. Therefore, it can be assumed that such a metal salt compound acts as a catalyst poison and causes a decrease in catalytic activity.

However, in the components recovered on the catalyst surface after the hydrogenation reaction according to the present invention, such a metal salt compound was not detected at an analytical level. Therefore, it can be seen that an alcohol component having two or more carbon atoms effectively dissolves such a metal salt compound to prevent adsorption to the catalyst, thereby contributing to improvement of performance by maintaining the activity and lifetime of the catalyst.

1: Liquid raw material mixer
2: Catalytic reactor
3: gas-liquid separator
4: Pneumatic device
5: Heat exchanger
6: Separation device

Claims (12)

In the presence of a hydrogenation catalyst and an alcohol having 2 to 8 carbon atoms,
Reacting at least one phthalate compound selected from phthalate, terephthalate, isophthalate and a carboxylic acid compound thereof with hydrogen,
Wherein the alcohol is contained in an amount of 10 to 40 parts by weight based on 100 parts by weight of the phthalate compound.
delete The method for hydrogenating a phthalate compound according to claim 1, wherein the phthalate compound contains a metal ion or a metal salt compound as an impurity.
The method for hydrogenating a phthalate compound according to claim 3, wherein the purity of the phthalate compound is 98% or more.
The method for hydrogenating a phthalate compound according to claim 1, wherein the phthalate compound is dioctyl terephthalate (DOTP).
delete The method according to claim 1, wherein the alcohol is ethanol, butanol or octanol.
delete The hydrogenation catalyst according to claim 1, wherein the hydrogenation catalyst is selected from the group consisting of hydrogenation of a phthalate compound containing at least one selected from the group consisting of ruthenium (Ru), palladium (Pd), rhodium (Rh), platinum (Pt) Way.
A process according to claim 1, wherein the process is carried out at a pressure of from 50 to 500 bar and at a temperature of from 50 to 500 ° C.
The method according to claim 1, wherein the alcohol and the phthalate compound react in a liquid phase and hydrogen reacts in a gas phase.
12. The method of claim 11, further comprising: mixing the phthalate compound with an alcohol to form a liquid mixture;
Elevating and raising the liquid mixture;
Supplying the mixture of the pressurized and warmed liquid phase and gaseous hydrogen into the reactor; And
And hydrogenating the phthalate compound with hydrogen.

Images