KR101797220B1 - Method for hydrogenation of phthalate compound - Google Patents

Abstract

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

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 an endocrine system that interferes with or disrupts human hormonal action 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.

The present invention provides a method for hydrogenating a phthalate compound which improves process performance and economic efficiency by improving the performance of a catalyst used for the hydrogenation reaction of a phthalate compound and maintaining the activity and prolonging the life time of the catalyst .

The present invention includes a step of reacting a phthalate compound with hydrogen in the presence of a supported catalyst containing a porous carrier carrying a transition metal to prepare a cyclohexanedicarboxylate compound, wherein the porous carrier has a pore diameter ranging from 50 nm to 10000 Nm of macropores of the total pore volume and less than 10% by volume of the total pore volume, and mesopores having a pore diameter in the range of 2 nm to 50 nm in an amount greater than 90% by volume of the total pore volume.

Hereinafter, a method for hydrogenating a phthalate compound according to a specific embodiment of the present invention will be described in detail.

According to an embodiment of the present invention, there is provided a process for producing a cyclohexanedicarboxylate compound by reacting a phthalate compound with hydrogen in the presence of a supported catalyst containing a porous carrier carrying a transition metal, wherein the porous carrier has a pore diameter range A process for hydrogenating a phthalate compound comprising macropores of 50 nm to 10000 nm in an amount of less than 10% by volume of the total pore volume and mesopores having a pore diameter in the range of 2 nm to 50 nm in an amount exceeding 90% by volume of the total pore volume Can be provided.

The present inventors have experimentally found that the use of a catalyst containing a porous support having a greatly improved surface area can maintain the activity of the catalyst used for the reaction for a long period of time and improve the performance of the catalyst by using the hydrogenation method of the phthalate compound And completed the invention.

Specifically, the method of hydrogenating the phthalate compound may be carried out under a supported catalyst containing a porous carrier carrying a transition metal. Particularly, the porous carrier preferably has macropores in a pore diameter range of 50 nm to 10000 nm of less than 10% by volume, or more than 1% by volume and less than 10% by volume of the total pore volume, The pores may comprise greater than 90% by volume, or greater than 90% by volume and not greater than 99% by volume of the total pore volume.

The ratio of the mesopore volume to the macro pore volume may be from 10 to 99, or from 20 to 95, or from 50 to 90. If the ratio of the mesopore volume to the macro pore volume is excessively decreased to less than 10, the surface area of the catalyst may decrease and the catalyst performance may decrease as the relative fine meso pore ratio decreases. In addition, the rate of decrease in the performance before and after the hydrogenation reaction of the phthalate compound increases, and it may be difficult to ensure the efficiency and economy of the process.

Accordingly, the BET (Brunauer, Emmett and Teller) specific surface area of the supported catalyst may be 50 m 2 / g or more, or 90 m 2 / g to 160 m 2 / g. The specific surface area refers to the surface area per unit mass of the particles. The BET measurement method is a type of vapor adsorption method in which molecules or ions are adsorbed on a solid surface and the surface area is measured at the adsorption amount. An example of the BET specific surface area measurement method is not limited, but can be calculated from the following Equation 1, for example.

[Equation 1]

In Equation 1, V = amount of adsorbed gas at pressure P, P0 = saturated vapor pressure, Vm = adsorption amount when monomolecular adsorption is completed, C = BET constant (constant relating to adsorption heat of adsorbed gas adsorbed on the sample ), P / P0 = correlation pressure of the adsorbent.

If the specific surface area of the supported catalyst is reduced to less than 50 m < 2 > / g, the catalytic performance may also decrease as the contact area of the catalyst with the active component decreases.

The average diameter of the pores contained in the porous carrier may be 2 nm to 30 nm, or 5 nm to 25 nm, or 8 nm to 19 nm. The average diameter of the pores included in the porous carrier means an average diameter of all the pores including all pores included in the porous carrier, for example, macro pores, mesopores, and micro pores. In the case of the porous carrier, the average diameter of the pores may be included in the diameter range of the mesopore, as it indicates a relatively high mesopore content.

The porous carrier may include at least one selected from the group consisting of activated carbon, silicon carbide, aluminum oxide, silicon dioxide, titanium dioxide, zirconium dioxide, magnesium dioxide, and zinc oxide.

The supported catalyst may contain a transition metal as an active component and the transition metal may include at least one selected from ruthenium (Ru), nickel (Ni), palladium (Pd), rhodium (Rh) . The content of the transition metal may be 0.01 wt% to 30 wt% with respect to the total weight of the supported catalyst.

The supported catalyst may further include at least one cocatalyst selected from the group consisting of sodium (Na), potassium (K), cesium (Cs), calcium (Ca), strontium (Sr), and barium .

The content of the cocatalyst may be 0.01% to 10% based on the total weight of the supported catalyst.

The object to be reacted in the method of hydrogenating the phthalate compound is a phthalate compound and hydrogen is added to the benzene ring of the phthalate compound by hydrogenation to convert it into the corresponding cyclohexanedicarboxylate compound.

The phthalate compound may include at least one selected from the group consisting of phthalate, terephthalate, isophthalate and a corresponding carboxylic acid. The corresponding carboxylic acid means a compound in which an ester functional group of phthalate, terephthalate or isophthalate is substituted with a carboxylic acid functional group, and specifically, for example, Phthalic acid, terephthalic acid, isophthalic acid, and the like.

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

[Chemical Formula 1]

In Formula 1, R ₁ and R ₁ 'are each independently the same or different and are a hydrogen atom, a straight chain or branched alkyl group having 1 to 20 carbon atoms, or 4 to 20 carbon atoms, 5 to 20 carbon atoms, or 5 to 10 carbon atoms to be.

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 Formula 2, R ₂ and R ₂ 'are each independently the same or different and are a hydrogen atom, a straight chain or branched chain alkyl group having 1 to 20 carbon atoms, or 4 to 20 carbon atoms, 5 to 20 carbon atoms, or 5 to 10 carbon atoms to be.

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 Formula 3, R ₃ and R ₃ 'are each independently the same or different and are a hydrogen atom, a straight chain or branched chain alkyl group having from 1 to 20 carbon atoms, or from 4 to 20 carbon atoms, or from 5 to 20 carbon atoms, or from 5 to 10 carbon atoms to be.

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. In this case, the cyclohexanedicarboxylate compound to be produced may be di (2-ethylhexyl) cyclohexane-1,4-dicar Di-ethylhexyl cyclohexane-1,4-dicarboxylate (DEHCH).

The purity of the phthalate compound may be 98% or more, or 99% or more. However, the present invention is not limited thereto, and phthalate compounds of commercially available quality and purity 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 .

The method of hydrogenating the phthalate compound may further include adding a cyclohexane dicarboxylate compound, which is a reaction product of the hydrogenation reaction, to 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 step of reacting a phthalate compound with hydrogen in the presence of a supported catalyst containing a porous carrier carrying the transition metal to produce a cyclohexanedicarboxylate compound comprises: elevating and raising the phthalate compound; Supplying the step-up and step-up phthalate compound and gaseous hydrogen into a reactor filled with a catalyst; And reacting the phthalate compound with hydrogen.

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

The target temperature for raising the phthalate compound to be introduced into the reactor may be in the range of 50 to 500 ° C, or 100 to 300 ° C. If the temperature of the phthalate compound is less than 50 캜, the catalyst is inactivated due to the low temperature, the viscosity of the mixture is high and the flow in the reactor is deteriorated, and the permeability of hydrogen to the phthalate compound in the liquid phase is lowered, If the temperature of the phthalate compound is excessively higher than 500 ° C, decomposition of the reaction product occurs to a great extent, which makes it difficult to produce a reactor, and rapid reaction may lead to difficulty in heat removal.

More specifically, the step of raising and raising the phthalate compound may be carried out simultaneously or sequentially, and the desired pressure and temperature may be reached by increasing the pressure and increasing the temperature several times in one or more steps.

The phthalate compound which has 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.

At this time, the pressure and temperature conditions of hydrogen can be controlled to be 50 to 500 bar, or 100 to 300 bar, and 50 to 500 ° C or 80 to 300 ° C, in the same manner as the temperature and pressure conditions of the phthalate compound have.

That is, the step of reacting the phthalate compound with hydrogen may be performed at a pressure of 50 to 500 bar and a temperature of 50 to 500 ° C. In the method of hydrogenating the phthalate compound, the phthalate compound may react in a gas phase in a liquid phase.

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

Examples of the reactor used in the method of hydrogenating the phthalate compound are not limited. For example, a tube type reactor as a tube type reactor and a reactor in which a solid hydrogenation catalyst is filled can be used.

1, the phthalate compound and hydrogen are heated and pressurized in the phthalate compound feedstock supply unit 10 and the hydrogen-containing gas supply unit 20, and fed to the top of the catalytic reactor 30 in an appropriate temperature and pressure state. do. The feedstock containing the supplied phthalate compound and hydrogen enters the upper portion of the reactor 30 to form a trickle flow and the hydrogenation reaction proceeds under the hydrogenation catalyst filled in the reactor 30, Is discharged to the lower portion of the reactor. Thereafter, the liquid hydrogenation product produced in the separator 40 located in the lower portion of the reactor is separated from the unreacted gaseous raw material. The separated gaseous feed can be recycled to the hydrogenation process. The recovered hydrogenation product can be finally separated through an additional purification process.

The reaction can be carried out by a continuous process, wherein the liquid phase represents a trickle flow flow in the reactor, and the liquid raw material and the gaseous raw material flow into the upper part of the reactor in the form of cocurrent.

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.

The step of reacting a phthalate compound with hydrogen in the presence of a supported catalyst containing a porous carrier carrying the transition metal to produce a cyclohexanedicarboxylate compound can be carried out in the presence of a supported catalyst containing a porous carrier carrying the transition metal, To a viscosity of 20 cP or more and lowering the viscosity of the phthalate compound in the reactor to 10 cP or less and then reacting with hydrogen.

The phthalate compound is not directly used for the hydrogenation reaction but the phthalate compound having a viscosity of 20 cP or more at room temperature (20 ° C) is lowered to 10 cP or less and the phthalate compound is reacted with gaseous hydrogen, It is possible to increase the stability of operation and economy of commercial scale through hot spot control.

The phthalate compound can be used for the reaction by lowering the viscosity to 10 cP or less through the step of increasing and raising the temperature using one or more heat exchangers. The step-up and step-up may be performed using one or more heat exchangers at a pressure of 50 to 500 bar, or 100 to 300 bar and at a temperature of 50 to 500 ° C, or 80 to 300 ° C. The number of the heat exchangers is not limited, and may be changed according to the heat exchange method for the liquid raw material. In the present invention, the heat exchange method may be performed through a reaction product after the reaction or a reaction heat recovered through the reactor jacket through a multi-tube cylindrical structure, but the present invention is not limited thereto.

Before the phthalate compound is fed to the reactor, the viscosity is lowered through a series of processes in the liquid phase to improve the flow of the liquid phase. Further, since the film thickness of the liquid raw material on each catalyst surface is thinned during the hydrogenation reaction of the phthalate compound injected into the reactor, uniform reaction occurs throughout the reactor, and due to the low viscosity of the phthalate compound, The reaction heat can be quickly removed through the cooling medium. In addition, not only the occurrence of hot spots in the reactor is suppressed by the above effect, but also the catalyst is uniformly participated in the reaction, thereby increasing the reactor efficiency, suppressing catalyst performance deterioration, and improving the reaction yield.

More specifically, the step of raising and raising the phthalate compound may be carried out simultaneously or sequentially, and the desired pressure and temperature may be reached by increasing the pressure and increasing the temperature several times in one or more steps. For example, the pressure of the phthalate compound may be increased first, and the pressure of the mixture may be raised through a heat exchanger to flow into the reactor in a liquid phase having an appropriate viscosity.

The viscosity of the phthalate compound generally has a viscosity of 20 cP or higher at room temperature before being added to the reactor. The phthalate compound can be 0.2 to 10.0 cP, or 2 to 5 cP, in the range of pressure and temperature conditions when entering the reactor, by performing the step of increasing the pressure and raising the temperature. When the viscosity of the phthalate compound is in the above range, it exhibits excellent flowability even after a lapse of a certain time in the reactor and can increase the reactivity with hydrogen.

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.

1 schematically shows a hydrogenation process reaction apparatus of the present invention.

The invention will be described in more detail in the following examples. However, the following examples are illustrative of the present invention, and the present invention is not limited by the following examples.

<Examples>

Example 1

100 parts by weight of dioctyl terephthalate (DOTP) having a purity of 99% was preheated at a pressure of 150 bar and a temperature of 120 ° C and injected into the catalytic reactor through a pump (the viscosity of the DOTP was 4.62 cP) Hydrogen (H ₂ ) was also fed to the top of the reactor after preheating to the same pressure and temperature.

The reactor is a single tube. In the outer jacket, the heat generated in the reactor is removed through hot oil, and the hydrogenation reaction is carried out while maintaining the temperature to obtain di (2-ethylhexyl) cyclohexane- Di-ethylhexyl cyclohexane-1,4-dicarboxylate.

The types of catalyst used in the reactor were as shown in Table 1 below, and the catalysts were cylinders of 3.2 mm in diameter and 3 mm in height.

< Comparative Example >

Comparative Example 1

The hydrogenation reaction was carried out in the same manner as in Example 1, except that the catalyst was changed as shown in Table 1 below.

Catalysts used in Examples and Comparative Examples division Active ingredient Carrier (aluminum oxide) Example 1 ruthenium Macro pore 1.11 vol%, mesopores 98.88 vol% Comparative Example 1 ruthenium Macro pores 11.38 vol%, mesopores 88.47 vol%

< Experimental Example  >

Evaluation of catalyst performance

The catalyst performances of the above Examples and Comparative Examples were evaluated by the following methods, and the results are shown in Table 2 below.

Experimental Example 1: Initial performance

(2-ethylhexyl) cyclohexane-1,4-dicarboxylate was added to 100 parts by weight of dioctyl terephthalate after the hydrogenation reaction was carried out using a catalyst which had never been used. cyclohexane-1,4-dicarboxylate, DEHCH) was calculated.

Experimental Example 2: Performance after 30 kg of DOTP

After carrying out a hydrogenation reaction on 30 kg of DOTP, the ratio (%) of the part converted into di (2-ethylhexyl) cyclohexane-1,4-dicarboxylate to the amount of 100 parts by weight of the charged DOTP was calculated.

Experimental Example 3: Performance reduction

The difference between the initial performance and the performance after 30kg reaction was calculated.

Experimental Example 4: Relative performance reduction ratio

Example 1 With respect to the amount of reduction in performance, when the reduction in performance is taken as 1, the relative reduction ratio (the reduction value of the comparative example divided by the reduction value of the embodiment 1) is calculated.

Experimental Example Results of Examples and Comparative Examples division Initial Performance
(unit: %) Performance after DOTP 30kg reaction
(unit: %) Performance Decrease (%) Relative performance reduction ratio Example 1 99.9 99.8 0.1 One Comparative Example 1 99.7 99.1 0.6 6

As shown in Table 2, in the case of the examples, the decrease in performance was 0.1% at the beginning of the reaction and at the end of the reaction, while the value of the comparative example was 0.6%.

That is, when the hydrogenation method of the phthalate compound of the above-mentioned example is used, the reduction rate of the catalytic performance is reduced to six times as compared with the comparative example, and the processability and economy are improved.

10: Terephthalate or phthalate compound raw material supply part
20: hydrogen-containing gas supply unit
30: Reactor performing hydrogenation reaction
40: Separator

Claims (19)

Reacting a phthalate compound with hydrogen in the presence of a supported catalyst containing a porous carrier carrying a transition metal to prepare a cyclohexanedicarboxylate compound,
Wherein the porous carrier comprises macropores having a pore diameter ranging from 50 nm to 10000 nm and mesopores having a pore diameter ranging from 2 nm to 50 nm,
Wherein said porous carrier comprises macropores in a pore diameter range of 50 nm to 10000 nm in an amount of less than 10% by volume of the total pore volume and mesopores in a pore diameter range of 2 nm to 50 nm in an amount greater than 90% by volume of the total pore volume and,
The BET specific surface area of the supported catalyst is from 90 m &lt; 2 &gt; / g to 160 m &
Wherein the average diameter of the pores contained in the porous carrier is 2 nm to 30 nm.
The method according to claim 1,
Wherein the ratio of the mesopore volume to the macropore volume is 10 to 99.
delete delete The method according to claim 1,
Wherein the porous carrier comprises at least one selected from the group consisting of activated carbon, silicon carbide, aluminum oxide, silicon dioxide, titanium dioxide, zirconium dioxide, magnesium dioxide and zinc oxide.
The method according to claim 1,
Wherein the phthalate compound comprises at least one selected from the group consisting of phthalate, terephthalate, isophthalate and a carboxylic acid compound thereof.
The method according to claim 1,
Wherein the phthalate compound contains a metal ion or a metal salt compound as an impurity.
The method according to claim 1,
Wherein the purity of the phthalate compound is 98% or more.
The method according to claim 1,
Wherein the phthalate compound is dioctyl terephthalate (DOTP).
The method according to claim 1,
Wherein the cyclohexanedicarboxylate compound is di (2-ethylhexyl) cyclohexane-1,4-dicarboxylate (DEHCH).
The method according to claim 1,
Wherein the transition metal comprises at least one selected from the group consisting of Ru, Pd, Rh, Pt and Ni.
The method according to claim 1,
Wherein the supported catalyst comprises at least one cocatalyst selected from the group consisting of sodium (Na), potassium (K), cesium (Cs), calcium (Ca), strontium (Sr) &Lt; / RTI &gt;
13. The method of claim 12,
Wherein the content of the cocatalyst is 0.01% to 10% with respect to the total weight of the supported catalyst.
The method according to claim 1,
The step of reacting a phthalate compound with hydrogen in the presence of a supported catalyst containing a porous carrier carrying the transition metal to produce a cyclohexanedicarboxylate compound,
Elevating and raising the phthalate compound;
Supplying the step-up and step-up phthalate compound and gaseous hydrogen into a reactor filled with a catalyst; And
And hydrogenating the phthalate compound with hydrogen.
15. The method of claim 14,
Wherein the phthalate compound reacts in a liquid state and hydrogen reacts in a vapor phase state.
The method according to claim 1,
Wherein the step of reacting the phthalate compound with hydrogen is carried out at a pressure of 50 to 500 bar and a temperature of 50 to 500 ° C.
The method according to claim 1,
The step of reacting a phthalate compound with hydrogen in the presence of a supported catalyst containing a porous carrier carrying the transition metal to produce a cyclohexanedicarboxylate compound,
A method for hydrogenating a phthalate compound, which comprises reacting a phthalate compound having a viscosity of 20 cP or more at room temperature in the presence of a supported catalyst containing a porous carrier for supporting the transition metal, wherein the viscosity of the phthalate compound is lowered to 10 cP or less, .
18. The method of claim 17,
Wherein the phthalate compound is used in the reaction by lowering the viscosity to 10 cP or lower through the step of increasing and raising the temperature by using at least one heat exchanger.
18. The method of claim 17,
A method for hydrogenating a phthalate compound, wherein the phthalate compound as a liquid raw material to be fed into the reactor is used in a hydrogenation reaction at a viscosity of 0.2 to 10 cP.

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