Patent Description:
A phthalate-based plasticizer accounts for <NUM>% of the global plasticizer market until the 20th century (see <NPL>). The phthalate-based plasticizer is an additive used for imparting flexibility, durability and cold resistance mainly to polyvinyl chloride (hereinafter, referred to as PVC) and lowering the viscosity during melting to improve processability. The phthalate-based plasticizer is added in various amounts to PVC and widely used in various applications from rigid products such as rigid pipes to soft products which may be used for such as food packaging materials, blood bags, flooring materials, etc. due to its soft and good flexibility. Therefore, it is more closely related to real life than any other material, and the direct contact with the human body may not avoidable.

However, in spite of the compatibility of the phthalate-based plasticizer with PVC and its excellent capability to impart flexibility, it has been argued recently about harmfulness of the PVC product containing the phthalate-based plasticizer that the phthalate-based plasticizer may leak out of the PVC product when used in real life, and act as a presumed endocrine disrupting (environmental hormone) substance and a carcinogen of the level of heavy metals (see <NPL>). Especially, since the report about the leakage of di-(<NUM>-ethyl hexyl) phthalate (DEHP), which has been the most used phthalate-based plasticizer in the US in the <NUM>, out of the PVC product, the interest in environmental hormones have been added in the <NUM> and global environmental regulations as well as various studies on hazards of the phthalate-based plasticizer to human have been started.

Therefore, in order to cope with environmental hormone problems and environmental regulations due to the leakage of the phthalate-based plasticizer, many researchers have been conducting research to develop a new, alter-native, non-phthalate-based plasticizer which is free of phthalic anhydride used in the production of phthalate-based plasticizers or a leakage inhibition technology which may inhibit the leakage of the phthalate-based plasticizer to greatly reduce the hazards to human and be in accordance with environmental standards.

As a non-phthalate-based plasticizer, a terephthalate-based plasticizer has been getting the spotlight, because it is equivalent to the phthalate-based plasticizer in terms of physical properties, but is free of environmental issues. A variety of terephthalate-based plasticizers have been developed and research on the development of a terephthalate-based plasticizer having excellent physical properties, as well as researches on facilities for preparing such the terephthalate-based plasticizer have been actively conducted. In terms of process design, more efficient, economical and simple process design has been required.

<CIT> and <CIT> disclose a neutralization/water separation device comprising a neutralization tank for producing a neutralized mixture, a water separation tank to divide the neutralization mixture into a floating layer and an aqueous layer, a partition wall extending downward from a ceiling of the water separation tank to provide a lower passage in the water separation tank, and a transfer line connected to a bottom surface of the neutralization tank, wherein the water separation tank comprises a first water separation part and a second water separation part partitioned by the partition wall, wherein a bottom surface of the water separation tank is gradually inclined downward toward a center thereof, wherein the water separation tank is connected to the neutralization tank.

An object of the present invention is to provide a neutralization/water separation device for an esterified product and a neutralization/water separation method for an esterified product, in which, when preparing a plasticizer, both neutralization reaction and water separation occur well to improve efficiency.

A neutralization/water separation device for an esterified product according to the present invention for achieving the above object includes: a neutralization tank in which a crude product mixture containing alcohol and an ester compound, a neutralizing agent, and water are put to produce a neutralized mixture;.

In addition, the neutralization/water separation device may further include a first discharge pump configured to discharge the resultant product contained in the floating layer from a sidewall of the second water separation part to the outside.

In addition, the neutralization/water separation device may further include a second discharge pump configured to discharge the precipitated salt contained in the aqueous layer from the bottom surface of the water separation tank to the outside.

In addition, the neutralization/water separation device may further include a propeller stirrer installed in the neutralization tank to stir the neutralized mixture.

In addition, the inclination may range of <NUM>° to <NUM>°.

In addition, the lower passage may have a height of <NUM>% to <NUM>% of a height of the partition wall.

In addition, the neutralized mixture may be alternately introduced into the plurality of water separation tanks.

In addition, the neutralized mixture may be introduced into the plurality of water separation tanks at the same time.

A neutralization/water separation method for an esterified product according to the present invention for achieving the above object includes: a step of putting a crude product mixture containing alcohol and an ester compound, a neutralizing agent, and water into a neutralization tank of a neutralization/water separation device according to the invention;.

In addition, in the step of producing the neutralized mixture, the neutralized mixture may be stirred using a propeller stirrer.

Particularities of other embodiments are included in the dependent claims, the detailed description and drawings.

The embodiments of the present invention may have at least the following effects.

Since the neutralization tank, in which the neutralization reaction occurs, and the water separation tank, in which the water separation occurs, are provided separately, both the neutralization reaction and the water separation may occur well to improve the efficiency.

In addition, since the neutralization tank is disposed at the upper side, the water separation tank is disposed at the lower side, and the neutralized mixture naturally flows from the neutralization tank to the water separation tank by the gravity, the separate transfer pump may not be required, and thus, the total volume may not increase, the structure may be simplified, and the neutralization/water separation device may be easily installed even in the narrow space, thereby to prevent the salt from being accumulated.

The effects of the prevent invention are not limited by the aforementioned description, and thus, more varied effects are involved in this specification.

Advantages and features of the present invention, and implementation methods thereof will be clarified through following embodiments described with reference to the accompanying drawings.

Unless terms used in the present invention are defined differently, all terms (including technical and scientific terms) used herein have the same meaning as generally understood by those skilled in the art. Also, unless defined clearly and apparently in the description, the terms as defined in a commonly used dictionary are not ideally or excessively construed as having formal meaning.

In the following description, the technical terms are used only for explaining a specific exemplary embodiment while not limiting the present invention. In this specification, the terms of a singular form may include plural forms unless specifically mentioned. The meaning of "comprises" and/or "including" does not exclude other components besides a mentioned component.

<FIG> is a schematic view of a neutralization/water separation tank <NUM>, which is combined to allow both neutralization and water separation to occur together, according to a related art.

In order to prepare a plasticizer, a mixing step, a neutralizing step, a water-separating step, a purifying step, and a filtering step are largely performed. In the mixing step, carboxylic acid and alcohol are mixed to cause an esterification reaction, thereby producing a crude product mixture containing the alcohol and the ester compound. In the neutralizing step, a neutralizing agent that is a basic aqueous solution is mixed to the crude product mixture to neutralize the crude product mixture. In the water-separating step, the neutralized mixture is divided into a floating layer <NUM> containing organic matters and an aqueous layer <NUM> containing salt <NUM>. In the purifying step, when the resultant product is discharged from the floating layer <NUM>, the residual alcohol is removed. Then, in the filtering step, the resultant product is filtered using a filter to acquire a plasticizer that is a final product.

In the various steps, as illustrated in <FIG>, the neutralization and water separation method according to the related art are performed in a neutralization/water separation tank <NUM> having the form of a single combined container. In addition, the inside of the neutralization/water separation tank <NUM> is divided into a first space <NUM> and a second space <NUM> by a partition wall <NUM>. The partition wall <NUM> extends upward from a bottom surface <NUM> of the neutralization/water separation tank <NUM> to form an upper passage <NUM>.

First, the crude product mixture is put into the first space <NUM> of the neutralization/water separation tank <NUM> through a first inlet <NUM>, and the neutralizing agent, which is the basic aqueous solution, and water are also put into the first space <NUM> through a second inlet <NUM>. Then, a circulation pump <NUM> connected to the first space <NUM> operates to mix and neutralize the crude product mixture, the neutralizing agent, and the water, thereby producing a neutralized mixture <NUM>. Then, immediately, the mixture <NUM> is divided into the floating layer <NUM> containing the organic matters and the aqueous layer <NUM> containing the salt <NUM>. When a water level of the neutralized mixture <NUM> is higher than that of the partition wall <NUM>, the floating layer <NUM> overflows to flow into the second space <NUM> through the upper passage <NUM> disposed above the partition wall <NUM>. Also, a first discharge pump <NUM> connected to the second space <NUM> operates to discharge the resultant product from the floating layer <NUM> to the outside. The salt <NUM> precipitated in the first space <NUM> does not flow into the second space <NUM> through the upper passage <NUM> and is precipitated in a lower portion of the first space <NUM>. The precipitated salt <NUM> is discharged from the aqueous layer <NUM> to the outside by a second discharge pump <NUM> connected to the first space <NUM>.

However, when external energy is applied to the neutralized mixture <NUM> within the first space <NUM> so that the neutralized mixture <NUM> quickly flows, the neutralization reaction may occur well. When the external energy is not applied to the neutralized mixture <NUM> to leave the neutralized mixture <NUM>, the water separation may occur well. That is, since the conditions in which the neutralization reaction and the water separation occur well are contradicted, both the neutralization reaction and the water separation may not occur well, and thus, there is a problem that the efficiency is deteriorated.

<FIG> is a schematic view of a neutralization/water separation device 3a, in which a neutralization tank 31a and a water separation tank 32a are separated from each other, according to the related art.

In order to solve the above problem, as illustrated in <FIG>, the neutralization tank 31a and the water separation tank 32a are separately separated from each other. That is, a crude product mixture is put into a neutralization tank 31a of the neutralization/water separation tank 3a through a first inlet 351a, and a neutralizing agent, which is a basic aqueous solution, and water are also put into the neutralization tank 31a through a second inlet 352a. Then, a circulation pump 36a connected to the neutralization tank 31a operates to mix and neutralize the crude product mixture, the neutralizing agent, and the water, thereby producing a neutralized mixture <NUM>. Also, the neutralized mixture <NUM> is transferred to the water separation tank 32a by using a transfer pump <NUM>. The inside of the water separation tank 32a is divided into a first space <NUM> and a second space <NUM> by a partition wall 33a. Also, the partition wall 33a extends upward from a bottom surface of the water separation tank 32a to form an upper passage 331a.

When the neutralized mixture <NUM> is put into the first space <NUM> through the transfer pump <NUM>, the neutralized mixture <NUM> is immediately divided into a floating layer <NUM> containing organic matters and an aqueous layer <NUM> containing salt <NUM>. When a water level of the neutralized mixture <NUM> is higher than that of the partition wall 33a, the floating layer <NUM> overflows to flow into the second space <NUM> through the upper passage 331a disposed above the partition wall 33a. Also, a first discharge pump <NUM> connected to the second space <NUM> operates to discharge the resultant product from the floating layer <NUM> to the outside. The precipitated salt <NUM> is discharged from the aqueous layer <NUM> to the outside by a second discharge pump <NUM> connected to the first space <NUM>. Thus, in the neutralization tank 31a, external energy is applied to the neutralized mixture <NUM>, and thus the neutralization reaction occurs well. In the water separation tank 32a, the external energy is not applied to the neutralized mixture <NUM> to leave the neutralized mixture <NUM>, and thus the water separation occurs well to improve efficiency.

However, since the neutralization/water separation device 3a requires a separate transfer pump <NUM>, there is a problem that a total volume increases, and the structure is complicated. In addition, when an operation of the neutralization/water separation device 3a is stopped, the neutralized mixture <NUM> may remain in the transfer pump <NUM>, and the salt <NUM> may be precipitated. When the salt <NUM> is accumulated in the transfer pump, a pressure inside the transfer pump increases, and thus, the efficiency and lifespan of the pump decrease.

<FIG> is a schematic view of a neutralization/water separation device <NUM> not according to the present invention.

Since a neutralization tank <NUM>, in which a neutralization reaction occurs, and a water separation tank <NUM> in which water separation occurs, are provided to be separated from each other, both the neutralization reaction and the water separation may occur well to improve efficiency. In addition, since the neutralization tank <NUM> is disposed at an upper side, the water separation tank <NUM> is disposed at a lower side, and a neutralized mixture naturally flows from the neutralization tank <NUM> to the water separation tank <NUM> by gravity, a separate transfer pump may not be required, and thus, a total volume may not increase, a structure may be simplified, and the neutralization/water separation device <NUM> may be easily installed even in a narrow space, thereby to prevent salt from being accumulated.

For this, the neutralization/water separation device <NUM> for an esterified product includes: a neutralization tank <NUM> in which a crude product mixture containing alcohol and an ester compound, a neutralizing agent, and water are put to produce a neutralized mixture <NUM>; a water separation tank <NUM> disposed below the neutralization tank <NUM> to divide the neutralization mixture <NUM> into a floating layer <NUM> and an aqueous layer <NUM>; a partition wall <NUM> extending downward from a ceiling 14a of the water separation tank <NUM> to provide a lower passage <NUM> in the water separation tank <NUM>; and a transfer line <NUM> configured to transfer the neutralized mixture <NUM> from the neutralization tank <NUM> to the water separation tank <NUM>. The water separation tank <NUM> includes: a first water separation part <NUM> into which the neutralized mixture <NUM> is introduced from the neutralization tank <NUM> through the transfer line <NUM>; and a second water separation part <NUM> into which the neutralized mixture <NUM> is introduced from the first water separation part <NUM> through the lower passage <NUM>, and the first water separation part <NUM> and the second water separation part <NUM> are partitioned by the partition wall <NUM>.

In order to prepare a plasticizer as described above, it is first subjected to a mixing step. In the mixing step, when carboxylic acid and alcohol are mixed to cause an esterification reaction, a crude product mixture containing the alcohol and the ester compound is produced.

Here, the carboxylic acid may be an alkyl carboxylic acid having <NUM> to <NUM> carbon atoms, a cycloalkyl carboxylic acid having <NUM> to <NUM> carbon atoms, an aromatic carboxylic acid having <NUM> to <NUM> carbon atoms, or a mixture thereof. For example, the carboxylic acid may be selected from caprylic acid, caproic acid, lauric acid, octanoic acid, decanoic acid, dodecanoic acid, ethanoic acid (acetic acid), propionic acid, butyric acid, pentanoic acid, hexanoic acid, ethylhexanoic acid, cyclohexane carboxylic acid, benzoic acid, cyclohexane <NUM>, <NUM>-dicarboxylic acid, cyclohexane <NUM>,<NUM>-dicarboxylic acid, cyclohexane <NUM>,<NUM>-dicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, and a combination thereof, preferably may be cyclohexane <NUM>,<NUM>-dicarboxylic acid, cyclohexane <NUM>,<NUM>-dicarboxylic acid, cyclohexane <NUM>,<NUM>-dicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, or combinations thereof, but is not limited thereto.

The alcohol may be aliphatic alcohol having a C1-C20 alkyl group, preferably aliphatic primary alcohol having a C3-C10 alkyl group. Here, the alcohols may have linear or branched alkyl and be alcohol mixed between structural isomers, and alcohols having different carbon numbers may be added as a mixture.

The esterification reaction of the alcohol component and the carboxylic acid may be performed in the presence of a catalyst. A material commonly used in the esterification reaction of alcohol may be used as the catalyst. For example, the catalyst may be one or more selected from acid catalysts such as sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, paratoluenesulfonic acid, methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, butanesulfonic acid, and alkyl sulfuric acid, metal salts such as aluminum lactate, lithium fluoride, potassium chloride, cesium chloride, calcium chloride, iron chloride, and aluminum phosphate, metal oxides such as heteropolyacids, and organic metals such as natural/synthetic zeolites, cation and anion exchange resins, tetraalkyl titanate, and polymers thereof, but is not limited thereto.

Next, a neutralizing step of neutralizing the crude product mixture with the basic neutralizing agent and a water-separating step of dividing the neutralized mixture into a floating layer <NUM> and an aqueous layer <NUM> are performed. As illustrated in <FIG>, the neutralization/water separation method for the esterified product is performed in the neutralization/water separation device <NUM> in which the neutralization tank <NUM> and the water separation tank <NUM> are separately separated from each other. Thus, external energy may be applied to only the neutralization tank <NUM>, and thus, the neutralization reaction and the water separation may occur more efficiently.

The neutralization tank <NUM> provides a space in which the crude product mixture containing the alcohol and the ester compound, the neutralizing agent, and the water are put to produce the neutralized mixture <NUM>. In the neutralization tank <NUM>, as illustrated in <FIG>, a propeller stirrer <NUM> is connected to the neutralization tank <NUM>. The propeller stirrer <NUM> is a stirrer in which at least one propeller is disposed on a long rod so as to be immersed in a liquid, and the rod rotates to stir the liquid. As illustrated in <FIG>, the propeller stirrer <NUM> may be provided in two, but is not limited thereto. For example, various numbers of propellers may be provided. Also, the propeller stirrer <NUM> may be installed substantially perpendicular to the neutralization tank <NUM>, but is not limited thereto. For example, the propeller stirrer <NUM> may be installed in various manner such as being installed to be inclined or horizontally installed. The propeller stirrer <NUM> may be installed to quickly and uniformly stir the neutralized mixture <NUM>.

The water separation tank <NUM> is disposed below the neutralization tank <NUM> and provides a space in which the neutralized mixture <NUM> is accommodated to be divided into a floating layer <NUM> and an aqueous layer <NUM>. Here, the floating layer <NUM> is a portion that contains organic matters to serve as a plasticizer later, and the aqueous layer <NUM> is a portion that contains water and salt <NUM>, which are produced by the neutralization reaction.

The transfer line <NUM> is connected to a bottom surface <NUM> of the neutralization tank <NUM> to transfer the neutralized mixture <NUM> to the water separation tank <NUM>. Since the transfer line <NUM> is connected to the bottom surface <NUM> of the neutralization tank <NUM>, the neutralized mixture <NUM> may naturally flow from the neutralization tank <NUM> to the water separation tank <NUM> by gravity without a separate transfer pump.

In the neutralization/water separation device <NUM> for the esterified product, the neutralization tank <NUM> is disposed at an upper side, and the water separation tank <NUM> is disposed at a lower side. Also, the neutralized mixture <NUM> naturally flows from the neutralization tank <NUM> to the water separation tank <NUM> by the gravity. Thus, since the separate transfer pump for transferring the neutralized mixture <NUM> to the water separation tank <NUM> is not required, a total volume does not increase, and a structure is simplified, and salt <NUM> is prevented from being accumulated.

The inside of the water separation tank <NUM> is divided into a first water separation part <NUM> and a second water separation part <NUM> by the partition wall <NUM>. The first water separation unit <NUM> provides a space by which the transfer line <NUM> for supplying the neutralized mixture <NUM> from the neutralization tank <NUM> and the second water separation part <NUM> are spaced apart from each other. In addition, the second water separation part <NUM> provides a space in which the neutralized mixture <NUM> is accommodated to be divided into the floating layer <NUM> and the aqueous layer <NUM>. The neutralized mixture <NUM> has large kinetic energy to flow from the neutralization tank <NUM> into the first water separation part <NUM> through the transfer line <NUM>. Also, the neutralized mixture <NUM> flows from the first water separation part <NUM> into the second water separation part <NUM> through the lower passage <NUM>. Here, since the transfer line <NUM> and the second water separation part <NUM> are spaced apart from each other by the first water separation part <NUM>, the kinetic energy of the neutralized mixture <NUM> is reduced in the second water separation part <NUM>. Thus, the water separation of the neutralized mixture <NUM> may occur well so that the neutralized mixture <NUM> is more quickly and clearly divided into the floating layer <NUM> and the aqueous layer <NUM>.

The partition wall <NUM> partitions the first water separation part <NUM> from the second water separation part <NUM>. As a result, when the neutralized mixture <NUM> is put into the second water separation part <NUM>, the kinetic energy may be significantly reduced, and thus the water separation may occur more efficiently. The partition wall <NUM> extends downward from a ceiling 14a of the water separation tank <NUM> to form a lower passage <NUM> therebelow. That is, the first water separation part <NUM> and the second water separation part <NUM> are not completely isolated by the partition wall <NUM> and are connected to each other through the lower passage <NUM>. Thus, the neutralized mixture <NUM> put into the first water separation part <NUM> naturally flows into the second water separation part <NUM> through the lower passage <NUM> disposed below the partition wall <NUM>.

It is preferable that the lower passage <NUM> has a height of <NUM>% to <NUM>% of the height of the partition wall <NUM>. If the lower passage <NUM> has a height lower than <NUM>% of the height of the partition wall <NUM>, a flow amount of neutralized mixture <NUM> may be significantly reduced, and an entire process time may be excessively consumed. Also, if the lower passage <NUM> has a height higher than <NUM>% of the height of the partition wall <NUM>, since the transfer line <NUM> and the second water separation part <NUM> are not sufficiently spaced apart from each other by the first water separation part <NUM>, the kinetic energy of the neutralized mixture <NUM> flowing into the second water separation part <NUM> may not be significantly reduced, and thus the efficiency of the water separation may be deteriorated.

A first discharge pump <NUM> for discharging the resultant product contained in the floating layer <NUM> to the outside may be connected to a sidewall of the second water separation part <NUM>. The first discharge pump <NUM> is connected to the sidewall of the second water separation part <NUM> at a height corresponding to the position at which the floating layer <NUM> is floated. Since the amount of crude product mixture, neutralizing agent, and water to be put and the amount of resultant product to be discharged by the first discharge pump <NUM> may be adjusted through a first inlet <NUM> and a second inlet <NUM>, the position at which the floating layer <NUM> is floated may be easily adjusted. That is, when the amount to be put increases, or the amount to be discharged decreases, the position at which the floating layer <NUM> is floated may increase in height, and when the amount to be put decreases, or the amount to be discharged increases, the position at which the floating layer <NUM> is floated may decrease in height. However, since it is preferable that the floating layer <NUM> is floated to a position higher than that of at least the lower passage <NUM>, the first discharge pump <NUM> may be connected to a position higher than the lower passage <NUM>.

A second discharge pump <NUM> for discharging the precipitated salt <NUM> contained in the aqueous layer <NUM> to the outside may be connected to the bottom surface <NUM> of the water separation tank <NUM>. While the neutralized mixture <NUM> flows through the first water separation part <NUM> and the second water separation part <NUM>, the neutralized mixture <NUM> may be divided into the floating layer <NUM> and the aqueous layer <NUM>, and the salt <NUM> contained in the aqueous layer <NUM> may be precipitated in a lower portion of the water separation tank <NUM>. The salt <NUM> is a compound in which an acidic anion and a basic cation are generated while the crude product mixture is neutralized by the neutralizing agent. Thus, the second discharge pump <NUM> is connected to the bottom surface <NUM> of the second water separation part <NUM> to discharge the precipitated salt <NUM> from the aqueous layer <NUM> to the outside.

A neutralization/water separation method for an esterified product according to includes: a step of putting a crude product mixture containing alcohol and an ester compound, a neutralizing agent, and water into a neutralization tank <NUM> of a neutralization/water separation device <NUM>; a step of mixing the crude product mixture, the neutralizing agent, and the water to produce a neutralized mixture <NUM>; a step of introducing the neutralized mixture <NUM> into a first water separation part <NUM> of the water separation tank <NUM>, which is disposed below the neutralization tank <NUM>, through a transfer line <NUM>; a step of introducing the neutralized mixture <NUM> into a second water separation part <NUM> of the water separation tank <NUM> through a lower passage <NUM>; a step of dividing the neutralized mixture <NUM> into a floating layer <NUM> and an aqueous layer <NUM>; and precipitate contained in the aqueous layer <NUM> is collected to the center of the bottom surface <NUM> of the water separation tank <NUM>.

Particularly, first, the crude product mixture containing the alcohol and the ester compound is put into the neutralization tank <NUM> of the neutralization/water separation device <NUM> through a first inlet <NUM>, and the neutralizing agent, which is the basic aqueous solution, and water are also put into the neutralization tank <NUM> through a second inlet <NUM>. Also, the crude product mixture, the neutralizing agent, and the water are mixed with each other to be neutralized, thereby producing the neutralized mixture <NUM>. An aqueous solution of a basic substance such as alkali metal hydroxide, alkaline earth metal hydroxide, or a mixture thereof may be used as the neutralizing agent. For example, an aqueous NaOH solution or an aqueous KOH solution may be used as the neutralizing agent.

Also, the propeller stirrer <NUM> installed in the neutralization tank <NUM> operates. The propeller stirrer <NUM> may rotate to stir the neutralized mixture <NUM> of the neutralization tank <NUM>, thereby quickly and uniformly neutralizing the neutralized mixture <NUM>.

The neutralized mixture <NUM> neutralized in the neutralization tank <NUM> has large kinetic energy to flow from the neutralization tank <NUM> to the first water separation part <NUM> through the transfer line <NUM>. Here, since the transfer line <NUM> is connected to the bottom surface <NUM> of the neutralization tank <NUM>, the neutralized mixture <NUM> may naturally flow from the neutralization tank <NUM> to the water separation tank <NUM> by the gravity without the separate transfer pump. Also, the neutralized mixture <NUM> put into the first water separation part <NUM> naturally flows into the second water separation part <NUM> through the lower passage <NUM> disposed below the partition wall <NUM>.

As described above, the first water separation part <NUM> provides a space by which the transfer line <NUM> and the second water separation part <NUM> are spaced apart from each other. Thus, since kinetic energy of the neutralized mixture <NUM> introduced into the second water separation part <NUM> decreases, the neutralized mixture <NUM> is more quickly and clearly divided into the floating layer <NUM> and the aqueous layer <NUM>. Also, a first discharge pump <NUM> connected to a sidewall of the second water separation part <NUM> operates to discharge the resultant product from the floating layer <NUM> to the outside. The discharged resultant product may be subjected to a purifying step of removing alcohol, which is the following process, and a filtering step to produce a final product, and the final product may be applied as a plasticizer. Also, a second discharge pump <NUM> connected to a bottom surface <NUM> of the water separation tank <NUM> discharges the salt <NUM> contained in the aqueous layer <NUM> to the outside.

In the above-described method, both the neutralization reaction and the water separation occur well to improve efficiency. In addition, since the neutralization tank <NUM> is disposed at an upper side, the water separation tank <NUM> is disposed at a lower side, and a neutralized mixture naturally flows from the neutralization tank <NUM> to the water separation tank <NUM> by gravity, a separate transfer pump may not be required, and thus, a total volume may not increase, a structure may be simplified, and the neutralization/water separation device <NUM> may be easily installed even in a narrow space, thereby to prevent salt from being accumulated.

<FIG> is a schematic view of a neutralization/water separation tank 1a not according to the present invention.

According to the first embodiment of the present invention, the bottom surface <NUM> of each of the water separation tank <NUM> is flat. However, if the bottom surface <NUM> of the water separation tank <NUM> is flat, the precipitated salt <NUM> is dispersed on the bottom surface <NUM> of the water separation tank <NUM>. Thus, it may not be easy to allow the second discharge pump <NUM> to discharge the salt <NUM> to the outside.

In the neutralization/water separation tank 1a, a bottom surface <NUM> of the water separation part <NUM> may be gradually inclined toward a center thereof as illustrated in <FIG>. That is, the bottom surface <NUM> of the water separation part <NUM> may have a conical shape. Also, a second discharge pump <NUM> may be connected to the center of the bottom surface <NUM> of the water separation part <NUM>. Thus, when salt <NUM> is precipitated, the salt <NUM> is collected to the center of the bottom surface <NUM> of the water separation part <NUM>, and a second discharge pump <NUM> may easily discharge the precipitated salt <NUM> to the outside.

According to the related art, when the neutralization/water separation device 3a is stopped for a long time, since the bottom surface of the neutralization tank 31a is flat, the precipitated salt <NUM> may be dispersed on the bottom surface of the neutralization tank 31a and then be accumulated and solidified at a corner of the bottom surface of the neutralization tank 31a. As a result, even if the neutralization/water separation device 3a operates again, the salt <NUM> may not be mixed with the neutralized mixture <NUM> to remain at the corner of the bottom surface <NUM> of the neutralization tank 31a.

Since the neutralization tank <NUM> is disposed at an upper side, and the water separation tank <NUM> is disposed at a lower side, even if the operation of the neutralization/water separation device <NUM> is stopped, the neutralized mixture <NUM> naturally flows from the neutralization tank <NUM> to the water separation tank <NUM> by gravity. Therefore, even if the neutralization/water separation device <NUM> is stopped for a long time, the salt <NUM> may not be precipitated on the bottom surface <NUM> of the neutralization tank <NUM> to fully flow into the water separation tank <NUM>, thereby preventing the salt <NUM> from being accumulated and solidified on the bottom surface <NUM> of the neutralization tank <NUM>.

<FIG> is a schematic view of a neutralization/water separation tank 1b according to an embodiment of the present invention.

As illustrated in <FIG>, in the neutralization/water separation tank 1b according to the embodiment of the present invention, a plurality of water separation tanks 12a and 12b are provided. Also, the plurality of water separation tanks 12a and 12b are connected in parallel to a neutralization tank <NUM>. For this, a transfer line <NUM> connected from a bottom surface <NUM> of the neutralization tank <NUM> is branched into a first transfer line <NUM> and a second transfer line <NUM>. Here, the first transfer line <NUM> is connected to a first water separation tank 12a, and the second transfer line <NUM> is connected to a second water separation tank 12b. Thus, when a neutralized mixture <NUM> is discharged from the neutralization tank <NUM> through the transfer line <NUM>, the neutralized mixture <NUM> may be introduced into the first water separation tank 12a through the first transfer line <NUM> and introduced into the second water separation tank 12b through the second transfer line <NUM>.

The neutralized mixture <NUM> may be alternately introduced into the plurality of water separation tanks 12a and 12b. That is, the first water separation tank 12a may serve as a main water separation tank. In general, the neutralized mixture <NUM> may be introduced into the first water separation tank 12a. In addition, the second water separation tank 12b may serve as a sub water separation tank. Thus, if the first water separation tank 12a is stopped due to failure, replacement, cleaning, etc., the neutralized mixture <NUM> may be introduced into the second water separation tank 12b. Alternatively, in order to prevent overload of the water separation tank, the neutralized mixture <NUM> may be alternately introduced into the first water separation tank 12a and the second water separation tank 12b at a predetermined time interval. Also, only the water separation tank <NUM> into which the neutralized mixture <NUM> is introduced and first and second discharge pumps <NUM> and <NUM>, which are connected to the water separation tank <NUM> may operate to discharge the resultant product and the salt <NUM>.

The neutralized mixture <NUM> may be introduced into the plurality of water separation tanks 12a and 12b at the same time. That is, when the neutralized mixture <NUM> is discharged from the neutralization tank <NUM> through the transfer line <NUM>, some of the neutralized mixture <NUM> may be introduced into the first water separation tank 12a, and the rest of the neutralized mixture <NUM> may be introduced into the second water separation tank 12b. As a result, the resultant product may be more quickly discharged to significantly improve productivity.

Claim 1:
A neutralization/water separation device (1b) for an esterified product, comprising:
a neutralization tank (<NUM>) in which a crude product mixture containing alcohol and an ester compound, a neutralizing agent, and water are put to produce a neutralized mixture (<NUM>);
a water separation tank (<NUM>) disposed below the neutralization tank (<NUM>) to divide the neutralization mixture (<NUM>) into a floating layer (<NUM>) and an aqueous layer (<NUM>);
a partition wall (<NUM>) extending downward from a ceiling of the water separation tank (<NUM>) to provide a lower passage (<NUM>) in the water separation tank (<NUM>); and
a transfer line (<NUM>) connected to a bottom surface of the neutralization tank configured to transfer the neutralized mixture (<NUM>) from the neutralization tank (<NUM>) to the water separation tank (<NUM>),
wherein the water separation tank (<NUM>) comprises:
a first water separation part into which the neutralized mixture (<NUM>) is introduced from the neutralization tank (<NUM>) through the transfer line (<NUM>); and
a second water separation part into which the neutralized mixture (<NUM>) is introduced from the first water separation part through the lower passage (<NUM>),
wherein the first water separation part and the second water separation part (<NUM>) are partitioned by the partition wall (<NUM>);
wherein a bottom surface (<NUM>) of the water separation tank (<NUM>) is gradually inclined downward toward a center thereof;
wherein the water separation tank (<NUM>) is provided in plurality and the plurality of water separation tanks (12a, 12b) are connected in parallel to the neutralization tank (<NUM>).