KR102490098B1 - Process for hydrogenation of phthalate compound - Google Patents

Abstract

The present invention relates to a method for hydrogenating phthalate compounds.
Specifically, in one embodiment of the present invention, after pre-mixing the liquid phthalate compound and the gaseous hydrogen, the mixed raw material is supplied to the reaction region of the trickle flow reactor to react.

Description

Method for hydrogenating phthalate compounds {PROCESS FOR HYDROGENATION OF PHTHALATE COMPOUND}

The present invention relates to a method for hydrogenating phthalate compounds.

A phthalate-based compound is a material widely used as a plasticizer for plastics, particularly polyvinyl chloride (PVC). For example, electrical and electronic products, pharmaceuticals, paint pigments, lubricants, binders, surfactants, adhesives, tiles, food containers, packaging materials, and the like are indeed very diverse.

However, as some phthalate compounds are known as substances that can cause environmental pollution and human endocrine disorders, regulations on their use are being strengthened, especially in developed countries such as Europe and the United States.

In particular, among phthalate-based plasticizers, di(2-ethylhexyl) phthalate (DEHP)), butyl benzyl phthalate (BBP), and di-n-butyl phthalate (di-n-butyl Some products, such as phthalate (DBP), are endocrine disrupters that interfere with or disrupt human hormone activity, and are suspected of being endocrine disruptors, and there is a movement to regulate them.

Thus, an eco-friendly plasticizer free from environmental hormone controversy while exhibiting performance equivalent to that of conventional plasticizers is being researched and developed, and as part of that, a method of using a compound obtained by hydrogenation of a benzene ring included in a phthalate compound is known.

Specifically, a method of reacting a liquid phthalate compound with gaseous hydrogen using a trickle bed reactor (TBR) has been proposed. Here, the trickle flow reactor is a reactor having a reaction region (ie, a catalyst layer) filled with a catalyst, and using a behavior in which the liquid raw material supplied to the reaction region moves downward by gravity and the gaseous raw material moves downward or upward by gravity. .

However, in using the trickle flow reactor, the high molecular weight of the phthalate compound and the low solubility of hydrogen therein decrease the reactivity at the upper part of the reaction zone, impair the overall process efficiency and economic efficiency, and lower the reaction conversion rate of the phthalate compound. become a factor

The present invention is to solve the phenomenon of reduced reactivity occurring at the upper end of the reaction zone in hydrogenating phthalate compounds using a trickle flow reactor, improve overall process efficiency and economic efficiency, and increase the reaction conversion rate of phthalate compounds.

In one embodiment of the present invention, in order to solve the above problems, after pre-mixing (pre-mixing) a liquid phthalate compound and gaseous hydrogen, and then supplying the mixed raw material to the reaction zone of the trickle flow reactor to react do.

According to the above embodiment, a liquid phthalate compound and gaseous hydrogen may be mixed in advance to secure a sufficient amount of dissolved hydrogen, and then the mixed raw material may be supplied to a reaction region in the trickle flow reactor to react.

Accordingly, it is possible to improve the reactivity at the upper part of the reaction zone in the trickle flow reactor, improve the overall process efficiency and economic efficiency of the hydrogenation reaction, and increase the reaction conversion rate of the phthalate compound.

1 is a diagram schematically showing a hydrogenation reaction apparatus used in the hydrogenation method of the present invention.

Since the present invention can apply various transformations and have various embodiments, specific embodiments will be exemplified and described in detail. However, it should be understood that this is not intended to limit the present invention to specific embodiments, and includes all transformations, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the present invention, if it is determined that a detailed description of related known technologies may obscure the gist of the present invention, the detailed description will be omitted.

In addition, terms including ordinal numbers such as first and second to be used below may be used to describe various components, but the components are not limited by the terms. These terms are only used for the purpose of distinguishing one component from another. For example, a first element may be termed a second element, and similarly, a second element may be termed a first element, without departing from the scope of the present invention.

Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

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

As pointed out above, at a certain temperature and pressure, the solubility of hydrogen (i.e., the amount of hydrogen that can be dissolved up to saturation) in phthalate compounds having a high molecular weight is itself low.

Moreover, a phthalate compound having a high molecular weight exhibits low fluidity in a trickle bed reactor (TBR), and dissolution of hydrogen therein proceeds slowly, so that it takes a long time to actually dissolve hydrogen to saturation.

Therefore, in using the trickle flow reactor, the high molecular weight of the phthalate compound and the low solubility of hydrogen therein decrease the reactivity at the upper part of the reaction zone, impair overall process efficiency and economic efficiency, and lower the reaction conversion rate of the phthalate compound. become a factor

In one embodiment of the present invention, in order to solve the above problem,

a gaseous raw material containing hydrogen under the condition that the Reynolds number is 1 to 300; And a liquid raw material containing a phthalate compound; preparing a mixed raw material of, and

In a reaction zone filled with a hydrogenation catalyst in a trickle flow reactor, reacting the mixed raw material,

A method for hydrogenating a phthalate compound is provided.

In one embodiment, the gaseous raw material containing hydrogen; and a liquid raw material including a phthalate compound; by pre-mixing (pre-mixing) to secure a sufficient amount of dissolved hydrogen, and then supplying the mixed raw material to the reaction zone in the trickle flow reactor to react, thereby increasing the reactivity at the upper end of the reaction zone. corresponds to a method of improving

Furthermore, the reactivity at the upper end of the reaction zone in the trickle flow reactor according to the embodiment is improved when the liquid phthalate compound and gaseous hydrogen are independently supplied to the reaction zone in the trickle flow reactor without mixing in advance. In contrast, it is a method that can improve the overall process efficiency and economy of the hydrogenation reaction and increase the reaction conversion rate of phthalate compounds.

Hereinafter, the above embodiment will be described in more detail.

Reynolds number of mixed stock

In the step of preparing the mixed raw material, the mixing means is not limited.

Specifically, any method, such as using a mixing device independent of the trickle flow reactor or using a mixing region formed in the trickle flow reactor, is not limited to obtaining a mixed raw material having a high amount of dissolved hydrogen.

However, if it takes an excessively long time to obtain a mixed raw material having a high dissolved hydrogen content, process efficiency decreases and costs increase.

However, in the above embodiment, in order to shorten the time for mixing the raw materials in advance, the raw materials are mixed under the condition that the Reynolds number is 1 to 300.

Here, ""Reynold's number (N _RE )" is a term generally used to quantify the fluidity of a fluid, and the larger the Reynolds number, the higher the fluidity. Specifically, in the present specification, "Reynold's number , N _RE )" is the ratio of the "force due to inertia" and the "force due to viscosity" of the fluid, and may be calculated by Equation 1 below, which is generally known in the art.

[Equation 1]

μ: Viscosity ρ: Density u _z : Linear velocity in the axial direction D _p : Diameter of flow path

Specifically, in the flow of a fluid, as the viscous force increases, the atoms of the fluid form a laminar flow, which is a flow in a state of parallel movement, respectively in the flow direction, and as the force due to inertia increases, the atoms of the fluid move randomly in the flow direction. form The Reynolds number is a value used to determine whether the flow state in the pipe is laminar flow or turbulent flow, and when the Reynolds number is less than about 2000, it is determined as laminar flow, and when it exceeds 2000, it is determined as turbulent flow. That is, the lower the Reynolds number of the fluid, the more constant the flow is.

In this regard, mixing the raw materials under the condition of low fluidity with a Reynolds number of less than 1 takes a long time until the amount of dissolved hydrogen in the mixed raw materials reaches a saturation concentration (ie, solubility of hydrogen), which is inefficient, and the size of the equipment etc. This can be a problem and increase the process cost.

On the other hand, in the range where the Reynolds number exceeds 300, the difference in the time required for the amount of dissolved hydrogen in the mixed raw material to reach the saturation concentration is insignificant, while the process cost for forming high fluidity increases, so such conditions should be avoided. is to do

On the other hand, when the raw materials are mixed under the condition of a Reynolds number of 1 to 300, an appropriate level of fluidity is formed, and the time required for the amount of dissolved hydrogen in the mixed raw materials to reach a saturated concentration may be reduced.

In addition, as the Reynolds number increases within this range, the time required for the amount of dissolved hydrogen to reach the saturation concentration is reduced, thereby reducing the time consumed for this process.

However, the above range is only an example, and when the raw materials are mixed, the Reynolds number is 1 or more, or 5 or more, or 10 or more, or 20 or more, and 300 or less, 100 or less, or 90 or less, or 80 or less, or 70 or less, or 65 or less.

mixing time of raw materials

In the embodiment, by mixing the raw materials under the condition that the Reynolds number is 1 to 300, a sufficient amount of dissolved hydrogen can be secured even when the raw materials are mixed within a short time of 1 to 500 seconds.

When mixing the above raw materials, it is also possible to control the mixing time by changing the Reynolds number within the range of 1 to 300.

However, the mixing time of the raw materials may vary depending on the mixing method and apparatus, and a detailed description thereof will be described later.

Mixing method of raw materials

In the step of preparing the mixed raw material, it has been described above that the mixing means is not limited.

Specifically, the step of preparing the mixed raw material may be performed using a mixing device independent of the trickle flow reactor or using a region filled with inactive beads on a reaction region filled with a hydrogenation catalyst in the trickle flow reactor. It can be used, and there is no limitation in obtaining a mixed raw material having a high amount of dissolved hydrogen no matter which method is used.

For example, as a mixing device independent of the trickle flow reactor, a generally known fluid mixing device, a line mixer, may be used.

This is physically independent of the reaction zone, and the mixed raw material produced by using the mixing device is recovered and supplied to the reaction zone, or discharged from the mixing device by installing a pipe physically connecting the mixing device and the reactor. The mixed raw material may be supplied to the reaction zone of the trickle flow reactor.

Meanwhile, a region filled with inactive beads may be formed on a reaction region filled with a hydrogenation catalyst in the trickle flow reactor, and the raw materials may be mixed in the mixing region.

When the raw materials are supplied onto the mixing zone filled with the inactive beads, the raw materials are mixed in the process of moving from the upper end of the mixing zone to the lower end by gravity, and then continuously into the reaction zone physically connected to the mixing zone. can be supplied.

In terms of process efficiency and cost, it may be advantageous to mix the raw materials using a mixing zone physically connected to the reaction zone and filled with inert beads, rather than a mixing device physically independent of the reaction zone.

Hereinafter, the mixing region formed in the trickle flow reactor will be described in more detail.

inert bead

The inert beads for forming the mixing region in the trickle flow reactor are not particularly limited as long as they are made of an inert material that does not affect mixing thereby and subsequent hydrogenation reaction.

As a non-limiting example, the inactive beads are ZrO ₂ , SiO ₂ , Al ₂ O ₃ , Na ₂ O, MgO, CaO, K ₂ O, Fe ₂ O ₃ , and a metal ceramic group including TiO ₂ ; a crystalline glass-ceramic group including a Li ₂ O-Al ₂ O ₃ -SiO ₂ system, a MgO-Al ₂ O ₃ -SiO ₂ system, and a ZnO-Al ₂ O ₃ -SiO ₂ system; And SiO ₂ -Na ₂ It may be made of any one selected from among inactive (ineart) materials containing; amorphous glass (glass) group containing the system.

Raw material mixing time (residence time in the mixing zone)

When mixing is performed using the mixing area filled with the inactive beads, the residence time of the raw materials in the mixing area may be the mixing time of the raw materials.

More specifically, the residence time of the raw materials in the mixing region is the time required for the raw materials to flow into the mixing region and completely flow out into the reaction region, and the region filled with the inactive beads (ie, the mixing region) is can be affected by length.

Although this is not particularly limited in the embodiment, the residence time of the raw materials in the mixing zone, that is, the mixing time of the raw materials may be adjustable within a range of 1 to 500 seconds. For example, the lower limit may be 1 second or more, 1.3 seconds or more, 1.5 seconds or more, 1.7 seconds or more, 1.9 seconds or more, 2.0 seconds or more, or 2.1 seconds or more, and the upper limit may be 500 seconds or less, 400 seconds or less, 300 seconds or less, 200 seconds or less, 100 seconds or less, 50 seconds or less, 40 seconds or less, 35 seconds or less, or 33 seconds or less.

When the mixing time of the raw materials is in the above range, a mixed raw material having a sufficient amount of dissolved hydrogen and fluidity in an appropriate range can be produced, and by supplying it to the reaction zone, the reactivity and reaction efficiency at the upper end of the reaction zone are improved, Overall process efficiency and economic efficiency can be improved, and the reaction conversion rate of phthalate compounds can be improved.

Here, the amount of dissolved hydrogen in the mixed raw material is the concentration value of gaseous hydrogen dissolved in liquid phthalate, and the saturated concentration may be a calculated value according to Equation 1 below, and Equation 1 follows Henry's law:

[Equation 1] G _(aq) = K P _G

In Equation 1, K is the gas constant of the hydrogen at the temperature at the time of the measurement, and P _G is the partial pressure of hydrogen in the raw material mixture.

hydrogenation reaction

Regardless of the mixing method of the raw materials, the step of supplying the mixed raw material to the reaction region filled with the hydrogenation catalyst and reacting the phthalate compound in the mixed raw material with hydrogen, the mixed raw material is supplied to the upper end of the reaction region. and reacting in the presence of the hydrogenation catalyst while the mixed raw material moves from an upper end to a lower end of the reaction zone.

The temperature and pressure conditions of the mixed raw material when inputting into the reaction zone are not particularly limited, but generally, the input raw material has the same pressure as the hydrogenation reaction condition, and the temperature condition has the same temperature as the hydrogenation reaction condition. According to this, in order to control the degree of exothermic heat in the reactor, the temperature may be lower than that of the hydrogenation reaction conditions.

Meanwhile, in the present specification, the hydrogenation conversion rate is defined as the mole% of the phthalate compound converted to the hydrogenation product through the raw material mixing step and the hydrogenation step among the phthalate compounds (100 mol%) of the liquid raw material.

As long as according to the above embodiment, a hydrogenation conversion rate of at least 43% or more, such as 43.5% or more, 43.7% or more, 43.7% or more, or 44.0% or more, can be secured. When the relative length of the mixing region is increased within the above range, the hydrogenation conversion rate may also be increased, and the maximum conversion rate may be 99%, 95 or less, or 90% or less.

Substances further included in liquid raw materials

In the raw material supply step, the liquid raw material supplied to the mixing region of the reactor may further include alcohol having 2 to 12 carbon atoms.

The alcohol is an alcohol having 2 or more carbon atoms, for example, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, pentanol, hexanol, heptane, which is an aliphatic alcohol having 2 to 12 carbon atoms, preferably 2 to 10 carbon atoms. One or a mixture thereof selected from ol, octanol (n-octanol, 2-ethylhexanol), nonanol, decanol, undecanol, and dodecanol may be used.

The usable alcohol may be selected differently depending on the specific type of the phthalate compound as a reaction object. For example, when a hydrogenation reaction is performed on dioctyl terephthalate, when an alcohol having 2 to 8 carbon atoms such as ethanol, butanol or octanol is used among the alcohols, the effect of improving the reactivity of the catalyst and extending the lifespan can be further increased. .

According to the present invention, the alcohol improves the flow of the liquid mixture by lowering the viscosity of the mixture in a liquid state before being mixed with the phthalate compound and supplied to the reactor. In addition, after being supplied to the reactor and reaching the reaction zone, reaction heat is absorbed while the hydrogenation reaction of the phthalate compound is progressing, 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, the reactivity of the catalyst is improved, and the physical and chemical adsorption of metal ions, metal salt compounds or other impurities contained in the phthalate compound, which is a raw material, to the catalyst is suppressed, can prolong life.

The alcohol is 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, and still more preferably about 10 parts by weight, based on 100 parts by weight of the phthalate compound as a reactant. to 30 parts by weight. If the alcohol is less than 5 parts by weight, the catalyst performance improvement effect is hardly shown, and if it is included in an excessive amount exceeding 60 parts by weight, it is necessary to increase the size of the reactor, and a lot of energy is consumed in the separation process, resulting in economic efficiency. this can be lowered

According to one embodiment of the present invention, in addition to the alcohol, a hydrogenation reaction may be performed by further mixing a cyclohexane dicarboxylate compound, which is a reaction product of the hydrogenation reaction. In this way, when the reaction is performed by further mixing the reaction product, a violent reaction in the reactor is suppressed, thereby reducing the phenomenon of control of the reaction temperature and local deterioration of catalyst performance on the catalyst.

The phthalate compound and the alcohol may further undergo a step of mixing to have a uniform concentration before being introduced into the reactor.

According to one embodiment of the present invention, the phthalate compound and alcohol are mixed before being introduced into the reactor, and the pressure and temperature of the mixture containing the phthalate compound and alcohol may be raised and introduced into the reactor.

More specifically, the step of raising the pressure and temperature of the mixture containing the phthalate compound and alcohol may be performed simultaneously or sequentially, and the desired pressure and temperature may be reached by raising the pressure and temperature several times at once or in a plurality of steps. may be For example, first, the pressure of the mixture containing the phthalate compound and the alcohol may be increased, and the temperature of the mixture having the increased pressure may be raised to introduce it into the reactor in a liquid state having an appropriate viscosity. According to one embodiment of the present invention, the viscosity of the mixture may be about 0.5 to about 20.0 cps in the range of pressure and temperature conditions when introduced into the reactor. When the viscosity of the mixture is within the above range, appropriate flowability and reactivity can be exhibited in the above reactor.

The target pressure to be increased to be introduced into the aforementioned reactor may be about 50 to about 500 bar, preferably about 100 to about 300 bar. If the pressure is less than 50 bar, it is difficult to obtain a desired level of conversion due to low reactivity, and if the pressure is too high, exceeding 500 bar, it is difficult to manufacture a reactor or the manufacturing cost may increase significantly.

In addition, the target temperature to be raised to be introduced into the aforementioned reactor may be in the range of about 50 to about 500 °C, preferably about 100 to about 300 °C. If the temperature is less than 50 ° C, the catalyst is inactivated due to the low temperature, the flow in the reactor is deteriorated due to the high viscosity of the mixture, and the permeability of hydrogen to phthalate compounds and alcohol in the liquid phase is lowered, so that the reaction does not occur properly even in the reactor. In addition, if the temperature is too high, exceeding 500 ° C., a lot of decomposition of the reactants occurs, there is difficulty in manufacturing the reactor, and rapid reaction may make it difficult to remove heat.

The mixture containing the phthalate compound and the alcohol, which has been increased in pressure and temperature by the above-described process, is introduced into the above-described reactor. In addition, gaseous hydrogen (H ₂ ) is introduced into the reactor through a separate supply line to perform a hydrogenation reaction.

At this time, the pressure and temperature conditions of hydrogen are the same as the temperature and pressure conditions of the mixture containing the phthalate compound and alcohol, about 50 to about 500 bar, preferably about 100 to about 300 bar and about 50 to about 50 bar. 500°C, preferably in the range of about 100 to about 300°C.

Control of temperature deviation and reaction amount in the reactor

During the hydrogenation reaction, the reactor can be operated to avoid local heat generation by controlling the temperature deviation per unit length (m) of the reactor to be maintained at 3° C. or less, for example, 2° C. or less. Since the lower the temperature deviation value per unit length of the reactor, the better, the lower limit is not limited, but may be, for example, 1 ° C. or more, and preferably 0 ° C. This temperature deviation can be measured from a number of temperature sensors installed along the height of the reactor.

In addition, during the hydrogenation reaction, the maximum reaction amount per actual reaction volume (m ³ ) of the reactor filled with the catalyst is maintained at 25 kmol/h or less, for example, 23 kmol/hr or less, so as not to generate local heat in the reactor. can do. Here, the amount of reaction can be calculated through the concentration change value by sampling each product according to the height of the reactor.

In order to adjust the reaction amount in the reactor, as described above, the flow rate or concentration of the reactants is adjusted, or for this purpose, an inert gas or an inert liquid is added together with the reactants, and the amount is adjusted. A method of adjusting and the like may be used.

For example, the mass flow rate of the phthalate compound introduced into the reactor, that is, the flow rate per unit area (m ² ) of the reactor filled with the catalyst (mass flux) may be 10,000 to 30,000 kg*hr ^-1 *m ^-2 , Specifically, it may be 10,000 to 15,000 kg*hr ^-1 *m ^-2 .

If the mass flow rate of the phthalate compound is less than 10,000 kg*hr ^-1 *m ^-2 per unit area (m ² ), the amount of raw material input is not sufficient, resulting in a decrease in productivity, and 30,000 kg*hr ^-1 *m ^-2 If it exceeds, the amount of liquid raw material injected into the reactor at once becomes too large, and the film thickness of the liquid raw material on the surface of the catalyst increases, and accordingly, hydrogen penetration becomes difficult, making it difficult for hydrogenation to occur, and side reactions increase. , local heat generation occurs, causing a problem in that the temperature deviation of the reactor intensifies.

Meanwhile, in order to minimize side reactions and improve process productivity by optimizing the ratio between reactants, the amount of hydrogen introduced into the reactor is 3 moles or more, or 4 moles or more, and 300 moles or less, or 100 moles or less, based on 1 mole of the phthalate compound. may be up to 50 moles, or up to 50 moles, or up to 30 moles.

If the amount of hydrogen is too small, less than 3 moles relative to 1 mole of the phthalate compound, the conversion rate of the reaction is low and a conversion rate of 95% or more cannot be obtained. It may be shortened, resulting in a lower conversion rate, an increase in by-products, or a rapid decrease in catalyst life. From this point of view, the amount of hydrogen can be controlled within the above range.

In addition, as a method for controlling the temperature deviation and reaction amount in the reactor, a method of dispersing reaction heat by installing a cooling member through which a refrigerant circulates inside or outside the reactor may be used.

At this time, as the refrigerant, a refrigerant known in the art may be used without limitation, such as cooling water, a methane-based refrigerant, a mixed refrigerant of ether and a lower alkane having 1 to 5 carbon atoms substituted or unsubstituted with fluorine. The type of the cooling member is not particularly limited, but an indirect cooling method such as a heat exchanger or a cooling jacket or a direct cooling method such as an inert gas or an inert liquid may be used.

In this way, when the hydrogenation reaction is performed by controlling the temperature difference in the reactor, the reaction occurs uniformly in the reactor, which not only controls the aromaticity of the hydrogenation product, but also increases the catalyst lifespan because the catalysts at the top and bottom of the reactor are evenly loaded. can be improved

Hydrogenation reaction object (phthalate compound)

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

The phthalate compound may be at least one selected from phthalate, terephthalate, isophthalate, and a carboxylic acid corresponding thereto.

First, the phthalate compound may be represented by Chemical Formula 1 below.

[Formula 1]

In Formula 1, R1 and R1' are each independently different from or the same, and contain hydrogen, 1 to 20 carbon atoms, preferably 4 to 20 carbon atoms, more preferably 5 to 20 carbon atoms, and still more preferably 5 to 10 carbon atoms. is a straight-chain or branched-chain alkyl group of

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

The terephthalate compound may be represented by Chemical Formula 2 below.

[Formula 2]

In Formula 2, R2 and R2' are each independently different from or the same, and contain hydrogen, 1 to 20 carbon atoms, preferably 4 to 20 carbon atoms, more preferably 5 to 20 carbon atoms, and still more preferably 5 to 10 carbon atoms. is a straight-chain or branched-chain alkyl group of

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

The isophthalate compound may be represented by Chemical Formula 3 below.

[Formula 3]

In Formula 3, R3 and R3' are each independently different from or the same, and contain hydrogen, 1 to 20 carbon atoms, preferably 4 to 20 carbon atoms, more preferably 5 to 20 carbon atoms, and still more preferably 5 to 10 carbon atoms. is a straight-chain or branched-chain alkyl group of

Specific examples of the isophthalate compound include dibutyl isophthalate (DBIP), dioctyl isophthalate (DOIP), diisononyl isophthalate (DINIP), or diisodecyl isophthalate (DIDIP). ; diisodecyl isophthalate) and the like, but is 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 99% or more, preferably about 99.5% or more, and more preferably about 98% or more, but is not limited thereto, and commercially available phthalate compounds of any quality and purity may be used. .

The hydrogenation process of phthalate compounds can be carried out in liquid phase or gas phase. According to one embodiment of the present invention, the hydrogenation reaction may proceed with the phthalate compound in a liquid state and the hydrogen in a gaseous state.

The temperature and pressure conditions of the gaseous raw material and liquid raw material introduced into the reactor are not particularly limited, but the gaseous raw material is at a pressure of about 100 to about 200 bar, preferably about 130 to about 160 bar and about 100 to about 200 ° C. , Preferably it can be adjusted to be in the range of about 130 to about 180 ℃, the liquid raw material is about 100 to about 200 bar, preferably about 130 to about 160 bar pressure and about 100 to about 200 ℃, preferably It can be adjusted to be in the range of about 130 to about 180 °C.

In this regard, the step of increasing the pressure and temperature of the liquid phthalate compound before the reaction; further comprising supplying the increased pressure and temperature of the liquid phthalate compound and gaseous hydrogen to the reactor filled with the hydrogenation catalyst, and the reactor It is possible to react the liquid phthalate compound and gaseous hydrogen under the hydrogenation catalyst in the elevated pressure and temperature. Of course, the average temperature and the maximum-minimum temperature deviation inside the reactor must be controlled as described above.

hydrogenation catalyst

The hydrogenation catalyst may include a transition metal as an active component, preferably at least one selected from the group consisting of ruthenium (Ru), palladium (Pd), rhodium (Rh), and platinum (Pt). there is.

Such a hydrogenation catalyst may be used by being supported on a carrier, and at this time, a carrier known in the art may be used without limitation as the carrier. Specifically, carriers such as zirconia (ZrO ₂ ), titania (TiO ₂ ), alumina (Al ₂ O ₃ ), and silica (SiO ₂ ) may be used.

When the hydrogenation catalyst is supported on a carrier, the amount of the active ingredient of the hydrogenation catalyst is preferably 3 parts by weight or less, 2 parts by weight or less, or 1 part by weight or less, and 0.1 parts by weight or more, or 0.3 parts by weight or less, based on 100 parts by weight of the carrier. It may be more than one part by weight. If the amount of the hydrogenation catalyst exceeds 3 parts by weight with respect to 100 parts by weight of the carrier, the reaction proceeds rapidly on the surface of the catalyst, and in this process, side reactions also increase, resulting in a rapid increase in the amount of by-products. If it is less than the above range, the yield of the hydrogenation reaction may decrease due to insufficient catalyst amount, so the above range is preferable.

In the present invention, the hydrogenation reaction conditions are not particularly limited, but for example, the reaction pressure may be 50 bar or more, or 100 bar or more, or 130 bar or more, and 220 bar or less, or 200 bar or less, or 180 bar or less. If the reaction pressure is less than 50 bar, the reaction does not occur well, and there may be various problems such as consumption of an excessive amount of catalyst and increase of by-products due to the residence time being too long. The above range is preferable because energy such as excessive electric power is required and the manufacturing cost of equipment such as a reactor may greatly increase.

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

After the reaction is completed, the resulting liquid hydrogenation reaction product and the unreacted gaseous raw material are separated. The separated gaseous raw material may be recycled to the hydrogenation process. In addition, the recovered hydrogenation reaction product can be finally separated through a process of reducing pressure and cooling.

hydrogenation reactor

1 is a diagram illustrating a hydrogenation reaction apparatus used in the hydrogenation method of the present invention. According to FIG. 1, the hydrogenation reaction device may include heat exchangers (a, b), a reactor (c), and a gas-liquid phase separator (d).

The heat exchangers (a, b) serve to increase the temperature of the gaseous raw material 1 and the liquid raw material 3 before being introduced into the reactor (c), and may be omitted if necessary.

The gaseous raw material 2 and the liquid raw material 4 are introduced into a tubular reactor c filled with a hydrogenation catalyst, and a hydrogenation reaction proceeds. The reactor may further include an outer jacket for heat removal in order to control reaction heat. At this time, the gaseous raw material 2 may be supplied from the upper end or lower end of the reactor, and the liquid raw material 4 may be supplied from the upper end of the reactor.

In the hydrogenation reaction of the phthalate compound, since gaseous reaction raw materials and liquid reaction raw materials react on the surface of the solid catalyst, a flow rate sufficient to form a film on the surface of the solid catalyst in the liquid phase must flow. Therefore, it is appropriate to operate in a way in which liquid raw materials are gradually shed by gravity from the top. On the other hand, when the liquid phase is introduced into the lower part, since the solid phase catalyst is submerged by the liquid phase reactant, it is difficult for the gas phase reactant to penetrate the solid phase catalyst, which may not be appropriate.

The reaction mixture (5) from the reactor (c) is passed to a gas-liquid separator (d), where a liquid reaction product (7) and a gaseous unreacted material (6) are separated. The separated reaction product 7 can be recovered and subjected to additional purification, and the gaseous unreacted material 6 is recycled for discharge or reuse.

However, since the location of each device in FIG. 1 can be changed and other devices not shown in FIG. 1 can be included as needed, the hydrogenation method of the present invention is not limited to the devices and process sequences shown in FIG. .

hydrogenation reaction product

The product whose aromaticity is controlled according to the hydrogenation method of the embodiment has low viscosity and surface mobility, and relatively little leaching to the product surface even after long-term use, and thus exhibits excellent properties as a plastic plasticizer.

The hydrogenated phthalate or terephthalate compound prepared in this way can be usefully used as a plasticizer. Specifically, the plasticizer containing the phthalate or terephthalate compound may be suitably used as a plasticizer for a resin selected from polystyrene, polyurethane, polybutadiene, silicone, thermoplastic elastomer, or copolymers thereof.

A resin composition containing the resin may be used in a variety of products. For example, it can be used for products such as stabilizers, paints, inks, liquid foaming agents (Masterbatch type), adhesives, and the like. In addition, food packaging film (eg, wrap), industrial film, compound, decorative sheet, decorative tile, soft sheet, hard sheet, wire and cable, wallpaper, foam mat, leather, flooring, tarpaulin, gloves, sealant, refrigerator Gaskets, hoses, medical devices, geogrids, mesh tarpaulins, toys, stationery, insulation tapes, clothing coatings, PVC labels used for clothing or stationery, bottle cap liners, stoppers for industrial or other purposes, artificial baits, It may be used in the manufacture of electronic device parts (eg, sleeves), automobile interior materials, adhesives, coatings, etc., but is not limited thereto.

Hereinafter, the action and effect of the invention will be described in more detail through specific examples of the invention. However, these embodiments are only presented as examples of the invention, and the scope of the invention is not determined thereby.

Hereinafter, various results have been examined, taking the case of forming a mixing region in a trickle flow reactor and using it to mix raw materials in advance as an example.

Examples 1 to 5

In Examples 1 to 5, a ruthenium (Ru) catalyst was used as a hydrogenation catalyst, and a reaction zone was formed by filling a single tube reactor with the hydrogenation catalyst, and the length of the reaction zone was unified to 1.5 m.

At this time, as the ruthenium (Ru) catalyst, the ruthenium content is 0.5 parts by weight relative to 100 parts by weight of the alumina (Al ₂ O ₃ ) carrier, and a cylindrical shape with a diameter of 3 mm and a height of 3 mm is used in Examples 1 to 5. was commonly used in

On the reaction area, inert beads of alumina (aluminum oxide) were filled to form a mixing area.

The inner diameter of the mixed region formed in Examples 1 to 5 is the same as 0.02646 m, but the length is 0.1 m (Example 1), 0.3 m (Example 2), and 0.5 m (Example 3) according to Table 1 below. ), 1 m (Example 4), and 1.5 m (Example 5).

After the reaction zone and the mixing zone were formed in Examples 1 to 5, a cooling fluid (Therminol 55) was flowed through the outer jacket of the reactor to control the temperature of the reactor to satisfy 150 ° C. supplied them.

Specifically, in each reactor of Examples 1 to 5, dioctyl terephthalate (DOTP) and 2-ethyl hexanol (2-EH) having a purity of 99% were added in a ratio of 8:2 (= DOTP: 2-EH), liquid raw materials and hydrogen mixed in a volume ratio were injected into the reactor, respectively, and a hydrogenation reaction was performed at a reaction pressure of 150 barg and a temperature of 150 °C. Here, the flow rate of the liquid raw material was 9.6 kg/hr and the flow rate of hydrogen was 2757 NLPH.

Comparative Example 1

In Comparative Example 1, a ruthenium (Ru) catalyst was used as a hydrogenation catalyst, and a reaction zone was formed by filling a single tube reactor with the hydrogenation catalyst, and the length of the reaction zone was unified to 1.5 m.

At this time, as the ruthenium (Ru) catalyst, the ruthenium content is 0.5 parts by weight relative to 100 parts by weight of the alumina (Al ₂ O ₃ ) carrier, and a cylindrical shape with a diameter of 3 mm and a height of 3 mm is used in Examples 1 to 5. was commonly used in

On the reaction zone, a separate mixing zone was not formed, and each liquid raw material and gaseous raw material were directly supplied to the reaction zone independently.

Specifically, in each reactor of Comparative Example 1, dioctyl terephthalate (DOTP) and 2-ethyl hexanol (2-EH) having a purity of 99% were added in a ratio of 8:2 (=DOTP: 2-EH), the liquid raw material and hydrogen mixed in a volume ratio were injected into the reactor, respectively, and a hydrogenation reaction was performed at a reaction pressure of 150 barg and a temperature of 150 °C. Here, the flow rate of the liquid raw material was 9.6 kg/hr and the flow rate of hydrogen was 2757 NLPH.

Experimental Example 1

After obtaining hydrogenated reaction products from Examples 1 to 5 and Comparative Example 1, respectively, they were quantitatively analyzed by Gas Chromatography (GS).

For reference, the length of the mixing zone used in each example, the mixing time of the raw material, the axial linear velocity (U _L ), the Reynolds number, the time to reach saturation concentration, and the hydrogenation reaction conversion rate were respectively evaluated and recorded in Table 1 below. did:

Axial linear velocity (m/s) of raw materials moving through the mixing zone: This is the value obtained by dividing the total volumetric flow rate (m ³ /hr) of the liquid material and the gaseous material by the inner diameter of the mixing zone.

Reynolds number of mixed raw materials: The ratio of the "force due to inertia" and the "force due to viscosity" of the fluid, and is a value calculated by the following equation (1):

[Equation 1]

μ: Viscosity ρ: Density u _z : Linear velocity in the axial direction D _p : Diameter of flow path

mix
area
length
(m) mix
hour
(candle) mix
of the realm
inner diameter
(m) mix
of the realm
cross-sectional area
(m ² ) mix
within the area
of raw materials
axial
linear speed
(m/s) mix
raw material
Reynolds number hydrogenation
reaction
conversion rate
(%) Comparative Example 1 - - - - - - 42.7 Example 1 0.1 2.1 0.02646 0.000550 0.006304 41.8 44.20 Example 2 0.3 6.4 0.02646 0.000550 0.006304 41.8 47.01 Example 3 0.5 10.7 0.02646 0.000550 0.006304 41.8 47.97 Example 4 One 21.4 0.02646 0.000550 0.006304 41.8 48.33 Example 5 1.5 32.1 0.02646 0.000550 0.006304 41.8 48.35

According to Table 1, it is confirmed that Examples 1 to 5 exhibit improved conversion rates compared to Comparative Example 1.

Through this, gaseous raw material containing hydrogen; and a liquid raw material including a phthalate compound; by pre-mixing to secure a sufficient amount of dissolved hydrogen, and then supplying the mixed raw material to the reaction zone in the trickle flow reactor to react (Examples 1 to 5), Compared to the case where the raw materials are independently supplied to the reaction zone in the trickle flow reactor (Comparative Example 1) without mixing in advance, the reactivity at the upper part of the reaction zone is improved, and the overall process efficiency and economics of the hydrogenation reaction are improved. It can be seen that the reaction conversion rate of the phthalate compound can be increased.

On the other hand, in Examples 1 to 5, as the length of the mixing region increases, the mixing time of the raw materials increases, and the solubility of hydrogen in the liquid raw material increases, so the final hydrogenation conversion rate relatively increases to a level of 49%. can know that However, in the above example, it can be seen that the conversion rate is hardly increased even if the mixing length is further increased while approaching the hydrogen saturation solubility in the 1m section or more.

More specifically, as the length of the mixing region increases, the time during which the raw material stays in the corresponding region increases, and the amount of gaseous hydrogen dissolved in the liquid phthalate may increase by the increased time. This directly leads to an increase in the amount of dissolved hydrogen in the mixed raw material discharged from the mixing zone, and the reactivity from the upper end of the reaction zone is increased, so that a hydrogenation reaction product with a high conversion rate can be obtained.

Although a conversion rate of 44% or more was confirmed in Table 1, it is also possible to further improve the conversion rate by increasing the length and/or cross-sectional area of the mixing region, the inner diameter of the inactive beads used in the mixing region, and the discharged from the mixing region. It will be possible to further increase the conversion rate by the Reynolds number of the mixed raw material, the amount of dissolved hydrogen, and the like.

Examples 6 to 13

In Examples 6 to 13, as in Examples 1 to 5, the reaction zone was formed by filling the hydrogenation catalyst in a single-tube reactor, and the length of the reaction zone was 1.5 m.

In the case of the mixed region filled with inactive beads, the length was the same as 2 m, but the inner diameter was changed according to Table 2 below.

Experimental Example 2

After obtaining the hydrogenation reaction products from Examples 6 to 13, respectively, the length of the mixing zone, the mixing time of the raw materials, the axial linear velocity of the raw materials moving through the mixing zone (U _L ), the Reynolds number, and the time to reach saturation concentration was evaluated in the same manner as in Experimental Example 1 and recorded in Table 2 below.

mix
area
length
(m) mix
of the realm
inner diameter
(m) mix
within the area
of raw materials
axial
linear speed
(m/s) mix
raw material
Reynolds number saturation
density
arrival
length
(m) saturation
density
arrival
mixing time
(candle) reaching saturation concentration
mixed zone
volume
(m ³ ) Example 6 2 0.03704 0.0032 15.2 1.1 46 0.001186 Example 7 2 0.03440 0.0037 17.2 1.1 40 0.001022 Example 8 2 0.03175 0.0043 19.8 1.1 34 0.000871 Example 9 2 0.02911 0.0051 22.9 1.2 31 0.000798 Example 10 2 0.02646 0.0053 26.9 1.3 28 0.000715 Example 11 2 0.02117 0.0097 39.1 1.5 21 0.000528 Example 12 2 0.01852 0.0127 48.8 1.6 17 0.000431 Example 13 2 0.01588 0.0172 63.1 1.7 13 0.000337

According to Table 2, as the inner diameter of the mixing area filled with the inert beads decreases, the flow rate of the raw materials passing through the small cross-sectional area increases, the fluidity and flowability of the mixed raw materials increase, and the liquid phase It can be seen that the rate at which vapor phase hydrogen is dissolved in phthalate is also increased. Accordingly, it can be confirmed that the time for the amount of dissolved hydrogen to reach the saturation concentration is shortened or the volume of the mixing region required to reach the saturation concentration is reduced.

a, b: heat exchanger
c: reactor
d: gas-liquid separator
1, 2: vapor phase raw material
3, 4: liquid raw material
5: reaction mixture
6: vapor phase unreacted
7: liquid reaction product

Claims (13)

a gaseous raw material containing hydrogen under the condition that the Reynolds number is 1 to 300; And a liquid raw material containing a phthalate compound; preparing a mixed raw material of, and
Reacting the mixed raw material in a reaction zone filled with a hydrogenation catalyst in a trickle flow reactor,
The step of preparing the mixed raw material is performed using a region filled with inactive beads on a reaction region filled with a hydrogenation catalyst in the trickle flow reactor.
Method for hydrogenating phthalate compounds.
According to claim 1,
The step of preparing the mixed raw material,
which is performed for 1 to 500 seconds,
Method for hydrogenating phthalate compounds.
delete According to claim 1,
The inactive beads,
a group of metal ceramics including ZrO ₂ , SiO ₂ , Al ₂ O ₃ , Na ₂ O, MgO, CaO, K ₂ O, Fe ₂ O ₃ , and TiO ₂ ;
a crystalline glass-ceramic group including a Li ₂ O-Al ₂ O ₃ -SiO ₂ system, a MgO-Al ₂ O ₃ -SiO ₂ system, and a ZnO-Al ₂ O ₃ -SiO ₂ system; and
Amorphous glass group including SiO ₂ -Na ₂ O system;
Which is made of any one selected from inert materials containing
Method for hydrogenating phthalate compounds.
According to claim 1,
The step of reacting the mixed raw material,
supplying the mixed raw material onto a reaction region filled with a hydrogenation catalyst in the trickle flow reactor;
Comprising the step of reacting in the presence of a hydrogenation catalyst while the supplied mixed raw material moves from the upper end to the lower end of the reaction zone,
Method for hydrogenating phthalate compounds.
According to claim 1,
The liquid raw material,
Which further comprises an alcohol having 2 to 12 carbon atoms,
Method for hydrogenating phthalate compounds.
According to claim 6,
The alcohol having 2 to 12 carbon atoms,
selected from ethanol, n-propanol, isopropanol, n-butanol, isobutanol, pentanol, hexanol, heptanol, octanol (n-octanol, 2-ethylhexanol), nonanol, decanol, undecanol, dodecanol, etc. One or a mixture thereof,
Method for hydrogenating phthalate compounds.
According to claim 1,
The amount of hydrogen supplied in the raw material supply step,
3 to 300 parts by mole relative to 1 part by mole of the phthalate compound,
Method for hydrogenating phthalate compounds.
According to claim 1,
The phthalate compound,
At least one selected from the group consisting of phthalates, terephthalates, isophthalates, and carboxylic acid compounds thereof,
Method for hydrogenating phthalate compounds.
According to claim 1,
The hydrogenation catalyst,
At least one selected from the group consisting of ruthenium (Ru), rhodium (Rh), palladium (Pd) and platinum (Pt),
Method for hydrogenating phthalate compounds.
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