KR20220005738A - Method for preparing adiponitrile - Google Patents

Abstract

The present invention relates to a method for preparing adiponitrile, which comprises the following steps of: supplying an acrylonitrile monomer stream, a catalyst stream, a hydrocarbon-based solvent stream, and an alcohol-based solvent stream to a dimerization reactor to perform a dimerization reaction to produce a reaction product; supplying a stream discharged from the dimerization reactor to a refining unit and separating a product-containing stream from the refining unit to supply the same to a thin film evaporation device; separating the liquid stream comprising the product concentrated in the thin film evaporation device to supply the same to a product purification column; separating the purified product from a stream discharged from an upper part of the product purification column to supply the same to a hydrogenation reactor; and supplying the hydrogenation reactor effluent stream to an adiponitrile separation column to separate adiponitrile from the upper effluent stream.

Description

Adiponitrile manufacturing method {METHOD FOR PREPARING ADIPONITRILE}

The present invention relates to a method for producing adiponitrile, and more particularly, to a method capable of increasing productivity and reducing production cost in producing adiponitrile.

Adiponitrile (adiponitrile) is used as an intermediate for the synthesis of hexamethylenediamine, a raw material of nylon, or used in the manufacture of waterproofing agents, vulcanization accelerators, and the like.

Conventionally, in order to produce such adiponitrile, a method of hydrocyanation of butadiene, a method of dimerizing an acrylonitrile monomer using a ruthenium-based catalyst, a method of dimerizing an acrylonitrile monomer through electrolysis, etc. this was used

The method for hydrocyanation of butadiene is to prepare adiponitrile by double hydrocyanation of 1,3-butadiene. Specifically, 3-pentenenitrile is prepared by first reacting the 1,3-butadiene with hydrogen cyanide (HCN), and the 3-pentenenitrile is purified and reacted with hydrogen cyanide secondarily to prepare adiponitrile. have. However, in this case, the primary reaction product includes 3-pentenenitrile, 2-methyl-3-butenenitrile, 4-pentenenitrile, 2-pentenenitrile, 2-methyl-2-butenenitrile, and methylglutaronitrile. There is a problem in that a large amount of by-products are generated and a complicated process for separating and purifying 3-pentenenitrile from the primary reaction product is required. In addition, a zero-valent nickel catalyst and a Lewis acid accelerator are used in the first reaction and the second reaction, and the catalyst is separated and recovered by distillation in order to reuse it. However, it is difficult to separate the catalyst from the acrylonitrile dimer such as methylglutaronitrile, and the effective area of the reactor is reduced due to the acrylonitrile dimer contained in the recovered catalyst stream, and the reaction efficiency is negatively affected. There is an additional problem of thermal decomposition of the catalyst as the acrylonitrile dimer accumulates in the catalyst stream.

In addition, the method of dimerizing the acrylonitrile monomer using a ruthenium-based catalyst is a method of preparing adiponitrile using a ruthenium-based compound in the catalyst. There was a problem in that the yield and selectivity of the nitrile were lowered. That is, as hydrogen is added, hydrogenation occurs along with the dimerization reaction of the acrylonitrile monomer, and as a by-product propionitrile is produced in large amounts, there is a problem in that the yield and selectivity of adiponitrile are deteriorated.

In addition, the method of dimerizing the acrylonitrile monomer through the electrolysis is a dimerization reaction of the acrylonitrile monomer in the electrolyte, and a side reaction occurs easily, the energy conversion efficiency is fundamentally low, and the yield of adiponitrile and low selectivity.

JP 1993-286918 A

The problem to be solved in the present invention is to prepare a product including an acrylonitrile dimer through acrylonitrile dimerization in order to solve the problems mentioned in the technology that is the background of the invention, and hydrogenate the product To provide a method for improving the yield of adiponitrile in manufacturing adiponitrile and reducing energy consumption during separation and purification of the product.

According to an embodiment of the present invention for solving the above problems, the present invention is a dimerization reaction by supplying an acrylonitrile monomer stream, a catalyst stream, a hydrocarbon-based solvent stream, and an alcohol-based solvent stream to a dimerization reactor to react with the reaction product creating a; The dimerization reactor discharge stream is supplied to a refining unit, separating the stream containing the product in the refining unit and supplying it to a thin film evaporation device; separating the liquid stream containing the product concentrated in the thin film evaporation device and supplying it to a product purification column; separating the purified product from the product purification column overhead effluent stream and feeding it to a hydrogenation reactor; preparing adiponitrile by hydrogenating the product in the hydrogenation reactor; and feeding the hydrogenation reactor effluent stream to an adiponitrile separation column to separate adiponitrile from the overhead effluent stream.

According to the adiponitrile manufacturing method of the present invention, a product containing dicyanobutene is prepared through acrylonitrile dimerization, and adiponitrile is produced by hydrogenating the product, thereby producing adiponitrile with high yield at low cost. Nitriles can be prepared.

In addition, in preparing the adiponitrile, it is possible to reduce energy consumption by designing a process to enable heat exchange during separation and purification of the product.

Figure 1 shows the process of the adiponitrile manufacturing method of an embodiment.
2 to 3 are enlarged views of the heat exchange flow in the adiponitrile manufacturing process in one embodiment, respectively.
Figure 4 shows the process of the adiponitrile manufacturing method of the comparative example.

The terms or words used in the description and claims of the present invention should not be construed as being limited to their ordinary or dictionary meanings, and the inventor must properly understand the concept of the term in order to best describe his invention. Based on the principle that can be defined, it should be interpreted as meaning and concept consistent with the technical idea of the present invention.

In the present invention, the term 'stream' may mean a flow of a fluid in a process, and may also mean a fluid itself flowing in a line (pipe). Specifically, the 'stream' may mean both the fluid itself and the flow of the fluid flowing within a line connecting each device. In addition, the fluid may refer to gas and liquid.

Hereinafter, the present invention will be described in more detail with reference to FIG. 1 to help the understanding of the present invention.

According to the present invention, a method for preparing adiponitrile is provided. The adiponitrile manufacturing method includes the steps of supplying an acrylonitrile monomer stream, a catalyst stream, a hydrocarbon-based solvent stream, and an alcohol-based solvent stream to the dimerization reactor 100 to perform a dimerization reaction to produce a reaction product; The output stream of the dimerization reactor 100 is supplied to the purification unit 200, separating the stream containing the product in the purification unit 200 and supplying it to the thin film evaporation device 300; separating the liquid stream containing the product concentrated in the thin film evaporation device 300 and supplying it to the product purification column 400; separating the purified product from the product purification column (400) overhead discharge stream and supplying it to a hydrogenation reactor (500); preparing adiponitrile by hydrogenating the product in the hydrogenation reactor 500; and supplying the effluent stream from the hydrogenation reactor 500 to the adiponitrile separation column 600 to separate adiponitrile from the overhead effluent stream.

According to an embodiment of the present invention, an acrylonitrile monomer stream, a catalyst stream, a hydrocarbon-based solvent stream, and an alcohol-based solvent stream may be supplied to the dimerization reactor 100 to perform a dimerization reaction to produce a reaction product.

The dimerization reaction of the acrylonitrile monomer may be a process for preparing a reaction product by dimerizing acrylonitrile by reacting it in a solvent including a proton donor solvent such as an alcohol-based solvent and an inert solvent such as a hydrocarbon-based solvent. . In this case, the reaction product may include a product, an unreacted acrylonitrile monomer, a catalyst, an alcohol-based solvent and a hydrocarbon-based solvent.

The hydrocarbon-based solvent may include, for example, at least one selected from the group consisting of benzene, toluene, hexane, cyclohexane, chlorobenzene, xylene, ethylbenzene, and cumene. As a specific example, the hydrocarbon-based solvent may be toluene.

The alcohol-based solvent may include, for example, at least one selected from the group consisting of methanol, ethanol, isopropyl alcohol, and cyclohexane alcohol. As a specific example, the alcohol solvent may be ethanol or isopropyl alcohol.

In the acrylonitrile dimerization reaction, the hydrocarbon-based solvent, the alcohol-based solvent and the catalyst may be supplied to the dimerization reactor 100 in a volume ratio of about 10:3:1, but is not limited thereto.

According to an embodiment of the present invention, the acrylonitrile dimerization reaction is performed at a temperature of 0 °C to 100 °C, 30 °C to 80 °C or 40 °C to 80 °C and 1 bar to 5 bar, 1 bar to 4 bar or 1 It can be carried out in the pressure range of bar to 3 bar. When the acrylonitrile dimerization reaction is performed in the above temperature and pressure range, the conversion rate of the product in the reaction product may be increased.

By dimerizing the acrylonitrile monomer, a product containing dicyanobutene (dicyanobutenes, DCBs) may be prepared. Specifically, the dicyanobutene is cis-1,4-dicyano-1-butene (cis-1,4-dicyano-1-butene, C-DC1B), trans-1,4-dicyano-1-butene (trans-1,4-dicyano-1-butene, T-DC1B) and 1,4-dicyano-2-butene (1,4-dicyano-2-butene, DC2B) at least one selected from the group consisting of may include

The catalyst may include at least one selected from the group consisting of phosphinite and phosphonite. For example, the catalyst may be represented by the following formula (1).

[Formula 1]

In Formula 1, R represents an alkyl group having 1 to 5 carbon atoms or a cycloalkyl group having 1 to 8 carbon atoms, R ₁ to R ₃ are each hydrogen, an alkyl group having 1 to 5 carbon atoms, an amino group or an alkoxy group, and n and m are each independently an integer of 1 to 2. For example, in Formula 1, R may be a methyl group, an ethyl group, an isopropyl group, or a cyclohexyl group.

According to an embodiment of the present invention, the reaction product generated through the dimerization reaction of the acrylonitrile monomer may be supplied to the purification unit 200 to separate and recover unreacted monomers, solvents and catalysts. For example, the purification unit 200 may include an unreacted material separation column 210 and a catalyst separation column 220 .

The dimerization reactor 100 effluent stream including the reaction product may be supplied to the unreacted material separation column 210 . In the unreacted material separation column 210, a portion of the product, catalyst and hydrocarbon-based solvent is separated as a bottom discharge stream, and an acrylonitrile monomer, an alcoholic solvent, and a hydrocarbon-based solvent discharged to the bottom discharge stream are separated as a top discharge stream. can be separated from the rest of

According to an embodiment of the present invention, the content of the hydrocarbon-based solvent in the unreacted material separation column 210 bottom discharge stream is 1 wt% to 80 wt%, 20 wt% to 70 wt%, or 40 wt% to 70 wt% can be In this way, without separating the entire amount of the alcohol-based solvent and the hydrocarbon-based solvent in the reaction product in the unreacted material separation column 210 to the upper portion, a part of the hydrocarbon-based solvent is discharged to the lower portion, thereby making it easier to separate the catalyst to be described later. have.

According to an embodiment of the present invention, the operating temperature of the unreacted material separation column 210 may be 20 °C to 150 °C. For example, the operating temperature of the unreacted material separation column 210 may be 40 °C to 130 °C, 50 °C to 120 °C, or 55 °C to 100 °C. By controlling the operating temperature of the unreacted separation column 210 in the above range, the product and catalyst are not distilled to the upper part, and unreacted unreacted acrylonitrile monomer, alcohol solvent and hydrocarbon solvent are selectively distilled to It can be recycled to the dimerization reactor 100 and reused. In addition, by operating the unreacted material separation column 210 within the above range, the entire amount of the hydrocarbon-based solvent is not separated to the upper portion of the unreacted material separation column 210 , and a portion can be discharged to the lower portion of the unreacted material separation column 210 . have.

According to an embodiment of the present invention, the unreacted material separation column 210 bottoms discharge stream includes a product, a catalyst and a hydrocarbon-based solvent, and the unreacted material separation column 210 bottoms discharge stream includes a product and a catalyst and a hydrocarbon-based solvent. It may be supplied to the catalyst separation column 220 to separate the solvent.

The catalyst separation column 220 may separate the catalyst using a separate extractant for selectively dissolving the catalyst. Specifically, a separate extractant is supplied to the catalyst separation column 220 , and the extractant may be separated from the upper portion of the catalyst separation column 220 by selectively dissolving a catalyst and a hydrocarbon-based solvent, and the catalyst separation column (220) A product may be separated from the bottom discharge stream, and the bottom discharge stream of the catalyst separation column 220 including the product may be supplied to a thin film evaporation device 300 to be described later. At this time, the unreacted material separation column 210 bottom discharge stream contains 1 wt% to 80 wt%, specifically 40 wt% to 70 wt% of a hydrocarbon-based solvent along with the product and catalyst. Due to this, the separation of the catalyst may be easier.

The extractant may include, for example, at least one selected from the group consisting of saturated hydrocarbons such as pentane, hexane, and heptane and unsaturated hydrocarbons such as hexene. As a specific example, the extractant may be hexene.

According to an embodiment of the present invention, the purification unit 200 may further include a catalyst recovery column 230 to separate the catalyst from the catalytic separation column 220 top discharge stream and reuse it for the dimerization reaction. . Specifically, the catalyst recovery column 230 may receive the upper exhaust stream of the catalyst separation column 220 to separate the catalyst, the hydrocarbon-based solvent, and the extractant, respectively. More specifically, in the catalyst recovery column 230, the catalyst and the hydrocarbon-based solvent are separated from the bottom discharge stream, circulated to the dimerization reactor 100 for reuse, and the extractant is separated from the top discharge stream to separate the catalyst. It can be recycled to the separation column 220 and reused.

The operating temperature of the catalyst recovery column 230 may be 30 °C to 200 °C. For example, the operating temperature of the catalyst recovery column 230 may be 30 °C to 180 °C, 40 °C to 180 °C, or 40 °C to 160 °C. By controlling the operating temperature of the catalyst recovery column 230 in the above range, the catalyst and hydrocarbon-based solvent are not distilled to the upper part, and the extractant is selectively distilled to dimerization reactor 100 and catalyst separation column 220, respectively. can be recycled and reused. At this time, since the upper discharge stream of the catalyst separation column 220 supplied to the catalyst recovery column 230 contains a hydrocarbon-based solvent along with the catalyst, the catalyst recovery column 230 uses a hydrocarbon-based solvent having a lower boiling point than the catalyst. By separating as a bottom discharge stream together with the catalyst, it is possible to effectively separate the catalyst while operating the catalyst recovery column 230 at a relatively low temperature, thereby reducing energy consumption.

According to an embodiment of the present invention, the catalytic separation column 220 bottom discharge stream may be supplied to a thin film evaporator 300 (thin film evaporator) to separate the product.

The thin film evaporation device 300 may receive the catalyst separation column 220 bottom discharge stream, separate the residual extractant and light by-products (Lights) from the top discharge stream, and circulate it to the catalyst separation column 220, Product may be separated from the bottoms effluent stream and fed to product purification column 400 .

The operating temperature of the thin film evaporation apparatus 300 may be 160 °C to 270 °C. For example, the operating temperature of the thin film evaporation device 300 may be 160 °C to 240 °C, 160 °C to 210 °C, or 160 °C to 190 °C. By operating the thin film evaporation device 300 at a relatively low temperature within the above range, it is possible to use a heating medium having a temperature lower than that of thermal oil, thereby reducing utility costs, and for heating the thin film evaporation device 300 . The in-process stream may be used as heating medium, or the heating medium may be heated using waste heat of the in-process stream. Through this, it is possible to reduce the energy consumption in manufacturing adiponitrile.

In addition, the operating pressure of the thin film evaporation apparatus 300 may be 20 torr to 500 torr. For example, the operating pressure of the thin film evaporation apparatus 300 may be 20 torr to 300 torr, 20 torr to 200 torr, or 20 torr to 100 torr.

The thin film evaporator 300 may use any type of thin film evaporator commonly used without limitation. For example, the thin film evaporation apparatus 300 may include a body part and a heating part provided on the outer surface of the body part in a shape surrounding the outer peripheral surface of the body part.

The body portion may be a cylindrical member that seals the upper and lower portions of the catalyst separation column 220, where evaporation of the lower exhaust stream is performed. The inside of the body portion may be maintained at a pressure of 20 torr to 500 torr, for example, in a vacuum state. Here, the body part may be connected to an external vacuum pump through a connection line, and the evaporation process may be performed in a vacuum state inside the body part by the vacuum pump.

An inlet for supplying an exhaust stream from a lower portion of the catalyst separation device to the inside of the body may be provided at an upper end of the body portion connected to the catalyst separation device.

In addition, a gaseous outlet for supplying a gaseous stream converted while a lower exhaust stream of the catalyst separation device supplied through the inlet is evaporated by heating of the heating part to the catalyst separation device may be provided at the other upper side of the upper end of the body.

In addition, the lower end of the body portion may be provided with a liquid phase outlet for supplying a non-evaporated, non-evaporated, concentrated liquid stream from the exhaust stream supplied through the inlet to the product purification column 400 to be described later.

The heating unit may be coupled and installed on the outer surface of the body to surround the outer peripheral surface of the body. Specifically, the heating unit is provided with a heating body having a space inside which a fluid can flow, an inlet provided on one side of the heating body and supplied with a heating medium, and an outlet provided on the other side of the heating body and through which the heating medium is discharged. can be In this case, the heating medium may be supplied to the inlet provided in the heating unit and transferred to the body in the process of being discharged through the outlet, thereby heating the lower discharge stream of the catalyst separation column 220 supplied to the inside of the body.

In addition, in the thin film evaporation apparatus 300, additional members are not specifically described, but may be appropriately provided as needed.

As an example, the heating medium may be an in-process stream. Specifically, when the product is separated using a distillation column, it must be operated at a high temperature, for example, at a high temperature of 200 ° C. or higher, in order to separate the product, the residual extractant, and the light by-product. ), it is possible to operate at a lower pressure compared to the distillation column, so that the liquid stream discharged from the thin film evaporation device 300 can be discharged at a temperature of 160 ° C. and heat exchange may be possible.

The heating medium used in the heating part of the thin film evaporation apparatus 300 may be an overhead discharge stream of the product purification column 400 to be described later. Specifically, as the heating medium, the product purification column 400 overhead discharge stream may be supplied through the inlet of the heating unit and discharged through the outlet. In this process, the catalytic separation device bottom exhaust stream inside the thin film evaporation device 300 may be heated, and the top exhaust stream of the product purification column 400 may be cooled. A portion of the stream of the product purification column 400 overhead that has passed through the heating unit may be refluxed to the product purification column 400 , and the remaining stream may be supplied to the hydrogenation reactor 500 . In addition, if necessary, the heating medium passing through the heating unit may be further heated using a separate heater, and the product purification column 400 top discharge stream passing through the heating unit is further cooled using a separate cooler can be

As another example, the heating medium may include at least one selected from the group consisting of thermal oil and steam. For example, the heating medium may use steam at a temperature level lower than that of the thermal oil. Specifically, in the present invention, since the product is separated using the thin film evaporation device 300, it can be operated at a relatively low temperature of 160 ° C. to 190 ° C. By using a heating medium with a temperature lower than that of thermal oil, utility costs can be reduced.

The in-process stream may be used as a means for heating the heating medium used in the heating part of the thin film evaporation apparatus 300 . Specifically, the heating medium supplied to the heating unit of the thin film evaporation device 300 is heated and then supplied to the inlet of the heating unit and discharged through the outlet, and the heating medium discharged through the outlet is the in-process stream and the heat exchanger. After being heated through heat exchange in 700 , it may be supplied back to the inlet of the heating unit.

The heating medium discharged through the outlet of the heating unit may be supplied through the inlet of the heating unit after heat exchange with the upper discharge stream of the product purification column 400 and the heat exchanger 700 . Specifically, in the heat exchanger 700 , the heating medium may be heated through heat exchange between the heating medium and the product purification column 400 top discharge stream, and the product purification column 400 top discharge stream may be cooled. The heated heating medium may be supplied to the inlet of the heating unit, discharged through the outlet, passed through the heat exchanger 700 and again supplied to the inlet to the heating unit, and may circulate. In addition, a portion of the cooled product purification column 400 overheads stream may be refluxed to the product purification column 400 , and the remaining stream may be supplied to the hydrogenation reactor 500 . In addition, if necessary, the heating medium that has passed through the heat exchanger 700 may be further heated using a separate heater, and the product purification column 400 top discharge stream that has passed through the heat exchanger 700 is separate. It can be further cooled using a cooler of

In this way, by using the in-process stream to heat the heating medium supplied to the heating unit of the thin film evaporation apparatus 300, or by using the in-process stream as the heating medium, energy consumption in manufacturing adiponitrile is reduced can do.

According to an embodiment of the present invention, the liquid stream containing the concentrated product discharged from the thin film evaporation device 300 is supplied to the product purification column 400, and high boiling point substances are separated and removed from the liquid stream, and , the product from which high boilers are removed may be separated from the overhead effluent stream and fed to the hydrogenation reactor 500 .

The operating temperature of the product purification column 400 may be 180 ℃ to 350 ℃. For example, the operating temperature of the product purification column 400 may be 190 °C to 330 °C or 200 °C to 300 °C. By operating the product purification column 400 at a temperature within the above range, it is possible to effectively separate the product and the high boiling point material.

In the hydrogenation reactor 500, adiponitrile may be prepared by hydrogenating the product that has undergone the separation and purification steps in the presence of hydrogen and a hydrogenation catalyst. The hydrogenation catalyst is a catalyst capable of selective hydrogenation, and may include, for example, at least one selected from the group consisting of palladium, platinum, copper and nickel. In some cases, the catalyst may be used by being supported on at least one carrier selected from the group consisting of gamma alumina, activated carbon, and zeolite.

The operating temperature of the hydrogenation reactor 500 may be, for example, 50 °C to 200 °C, 60 °C to 170 °C, or 60 °C to 140 °C. The hydrogenation reactor 500 may be operated at a temperature within the above range, whereby the hydrogenation reaction may proceed in a liquid phase. Specifically, in the hydrogenation reactor 500, in the dicyanobutene included as the product, by breaking the double bond of butene and converting it to a saturated hydrocarbon, adiponitrile can be prepared.

The discharge stream from the hydrogenation reactor 500 is a stream containing adiponitrile produced through a hydrogenation reaction of a product containing dicyanobutene, and may be supplied to the adiponitrile separation column 600 . The adiponitrile separation column 600 may remove high-boiling materials from the bottom discharge stream and separate high-purity adiponitrile from the top discharge stream.

The operating temperature of the adiponitrile separation column 600 may be 240 °C to 350 °C. For example, the operating temperature of the adiponitrile separation column 600 may be 240 °C to 350 °C, 250 °C to 320 °C, or 260 °C to 300 °C. By operating the adiponitrile separation column 600 at a temperature within the above range, adiponitrile of high purity may be separated and recovered.

According to an embodiment of the present invention, the adiponitrile manufacturing method, if necessary, a distillation column (not shown), a condenser (not shown), a reboiler (not shown), a valve (not shown), a pump (not shown) , a separator (not shown) and a mixer (not shown) may be additionally used.

As mentioned above, the adiponitrile manufacturing method according to the present invention has been shown in the description and drawings, but the description and drawings above describe and show only the essential components for understanding the present invention, and the description and drawings shown in the description and drawings In addition to the process and apparatus, processes and apparatus not separately described and not shown may be appropriately applied and used for carrying out the method for preparing adiponitrile according to the present invention.

Hereinafter, the present invention will be described in more detail by way of Examples. However, the following examples are intended to illustrate the present invention, and it is apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention, and the scope of the present invention is not limited thereto.

Example

Example 1

With respect to the process flow diagram shown in FIG. 1, the process was simulated using Aspen Plus simulator of Aspen Corporation.

Specifically, 9.5 ton/hr of acrylonitrile monomer as a monomer, 3.1 ton/hr of isopropyl alcohol and 33.9 ton/hr of toluene as a solvent are supplied to the dimerization reactor 100, and isopropyl diphenylphosphinite ( Isopropyl diphenylphosphinite) was supplied to carry out the dimerization reaction of the acrylonitrile monomer.

The reaction-completed dimerization reactor 100 discharge stream is supplied to the unreacted material separation column 210 of the refining unit 200, and an overhead discharge stream containing a portion of unreacted acrylonitrile monomer, isopropyl alcohol and toluene is removed. It was circulated to the dimerization reactor 100 and the bottoms effluent stream comprising the remainder of the product, catalyst and toluene was fed to the catalyst separation column 220 . At this time, the operating temperature of the dimerization reactor 100 was controlled to 60 ℃, the upper temperature of the unreacted separation column 210 was controlled to 42.3 ℃, the lower temperature was controlled to 91.4 ℃.

In the catalyst separation column 220, hexene is introduced as an extractant, and the top discharge stream containing the catalyst, toluene, and the extractant is supplied to the catalyst recovery column 230, and the bottom discharge stream containing the product is supplied to a thin film evaporation device ( 300) was supplied.

In the catalyst recovery column 230 , the top effluent stream containing the extractant is circulated to the catalyst separation column 220 , and the bottom effluent stream containing the catalyst and toluene is circulated to the dimerization reactor 100 .

The gaseous stream converted while being evaporated by heating in the thin film evaporation device 300 was condensed in a condenser and then circulated to the catalyst separation column 220 , and the concentrated liquid stream was supplied to the product purification column 400 . At this time, steam was used as the heating medium supplied to the heating unit of the thin film evaporation device 300 , and the steam was supplied through the inlet and discharged through the outlet.

The output stream from the product purification column 400 is supplied to the hydrogenation reactor 500 for hydrogenation reaction, and the exhaust stream from the hydrogenation reactor 500 is supplied to the adiponitrile separation column 600, and the adiponitrile separation column (600) Adiponitrile was separated from the overhead effluent stream.

At this time, the pressure, temperature and composition of the stream related to the thin film evaporation device 300 and the product purification column 400 are shown in Table 1 below, and the amount of heat for heating the heating medium of the thin film evaporation device 300 ( H1) and the amount of heat (H2) that can be obtained when condensing the product purification column 400 overhead stream is shown in Table 2 below.

Example 2

In Example 1, it was carried out in the same manner as in Example 1, except that the product purification column 400 overhead discharge stream was used as the heating medium of the thin film evaporation apparatus 300.

Specifically, as shown in FIG. 2 below, as a heating medium of the thin film evaporation device 300, the upper discharge stream of the product purification column 400 at 218° C. is supplied through the inlet of the heating unit, and after being discharged to the outlet, some streams are It was refluxed to the product purification column (400) and the remaining stream was fed to the hydrogenation reactor (500).

Example 3

In Example 1, the product purification column 400 top discharge stream as a heating medium of the thin film evaporation device 300 is supplied to the heat exchanger 700 as shown in FIG. 3, and the product in the heat exchanger 700 The same method as in Example 1 was performed except that steam produced through heat exchange with the purification column 400 upper exhaust stream was supplied through the inlet of the heating unit of the thin film evaporation device 300 .

comparative example

Comparative Example 1

With respect to the process flow diagram shown in FIG. 1, the process was simulated using Aspen Plus simulator of Aspen Corporation.

Specifically, 9.5 ton/hr of acrylonitrile monomer as a monomer, 3.1 ton/hr of isopropyl alcohol and 33.9 ton/hr of toluene as a solvent are supplied to the dimerization reactor 100, and isopropyl diphenylphosphinite ( Isopropyl diphenylphosphinite) was supplied to carry out the dimerization reaction of the acrylonitrile monomer.

The reaction-completed dimerization reactor 100 discharge stream is supplied to the unreacted material separation column 210 of the refining unit 200, and an overhead discharge stream containing a portion of unreacted acrylonitrile monomer, isopropyl alcohol and toluene is removed. It was circulated to the dimerization reactor 100 and the bottoms effluent stream comprising the remainder of the product, catalyst and toluene was fed to the catalyst separation column 220 . At this time, the operating temperature of the dimerization reactor 100 was controlled to 60 ℃, the upper temperature of the unreacted separation column 210 was controlled to 42.3 ℃, the lower temperature was controlled to 91.4 ℃.

In the catalyst separation column 220, hexene is input as an extractant, the top discharge stream containing the catalyst, toluene, and the extractant is supplied to the catalyst recovery column 230, and the bottom discharge stream containing the product is supplied to the product separation column ( 800) was supplied.

In the catalyst recovery column 230 , the top effluent stream containing the extractant is circulated to the catalyst separation column 220 , and the bottom effluent stream containing the catalyst and toluene is circulated to the dimerization reactor 100 .

The overhead effluent stream from the product separation column 800 is circulated to the catalytic separation column 220 , and the bottom effluent stream is fed to the product purification column 400 .

The output stream from the product purification column 400 is supplied to the hydrogenation reactor 500 for hydrogenation reaction, and the exhaust stream from the hydrogenation reactor 500 is supplied to the adiponitrile separation column 600, and the adiponitrile separation column (600) Adiponitrile was separated from the overhead effluent stream.

At this time, the pressure, temperature and composition of the stream related to the thin film evaporation device 300 and the product purification column 400 are shown in Table 1 below, and the amount of heat ( H1) and the amount of heat (H2) that can be obtained when condensing the product purification column 400 overhead stream is shown in Table 2 below.

Example 1 Comparative Example 1 S1 S2 S3 S1 S2 S3 pressure (torr) 10 bar 35 90 10 bar 110 90 Temperature (℃) 52 181 218 52 220 218 Composition (wt%) extractant 6.4 0.0 0.0 6.2 0.0 0.0 menstruum 0.0 0.0 0.0 0.0 0.0 0.0 DCBs 81.8 89.2 95.5 62.9 89.2 95.4 Etc 11.8 10.8 4.5 30.9 10.8 4.6 Sum 100.0 100.0 100.0 100.0 100.0 100.0

Example 1 Comparative Example 1 H1 H2 H1 H2 Calorie (Gcal/hr) 1.3 -1.3 1.4 -1.3

Referring to Tables 1 and 2, in the case of Example 1 in which the product is separated using the thin film evaporation device 300, it may be possible to operate at 181 ° C. In this case, the product purification column 400 at 218 ° C. It can be seen that 37 °C lower than the overhead stream. In addition, since the amount of heat for heating the heating medium in the thin film evaporation device 300 and the amount of heat recovered during condensation of the upper exhaust stream of the product purification column 400 are the same, as in Examples 2 and 3, the The product purification column 400 overhead discharge stream may be used as a heating medium of the thin film evaporation apparatus 300, or the entire amount of heat for heating the heating medium may be replaced by using the product purification column 400 overhead discharge stream. it can be seen that

In comparison, in Comparative Example 1 in which a distillation column is used as the product separation column 800 instead of the thin film evaporation device 300, the temperature of the output stream at the bottom of the product separation column 800 is 220°C and the product is 218°C. It can be seen that it is not possible to heat the product separation column 800 bottoms effluent stream using the product purification column 400 overheads effluent stream because it is high compared to the purification column 400 overheads effluent stream. In addition, since the heat exchange is impossible, there is a problem in that energy consumption increases because an amount of heat of 1.4 Gcal/hr is additionally required to heat the discharge stream at the bottom of the product separation column 800 .

100: dimerization reactor
200: refining unit
210: unreacted material separation column
220: catalyst separation column
230: catalyst recovery column
300: thin film evaporation device
310: body portion
320: heating unit
330: inlet
340: outlet
400: product purification column
500: hydrogenation reactor
600: adiponitrile separation column
700: heat exchanger
800: product separation column

Claims (13)

supplying an acrylonitrile monomer stream, a catalyst stream, a hydrocarbon-based solvent stream, and an alcohol-based solvent stream to a dimerization reactor to perform a dimerization reaction to produce a reaction product;
The dimerization reactor discharge stream is supplied to a refining unit, separating the product-containing stream in the refining unit and supplying it to a thin film evaporation device;
separating the liquid stream containing the product concentrated in the thin film evaporation device and supplying it to a product purification column;
separating the purified product from the product purification column overhead effluent stream and feeding it to a hydrogenation reactor;
preparing adiponitrile by hydrogenating the product in the hydrogenation reactor; and
feeding the hydrogenation reactor effluent stream to an adiponitrile separation column to separate adiponitrile from the overhead effluent stream. According to claim 1,
The purification unit adiponitrile manufacturing method comprising an unreacted material separation column and a catalyst separation column. 3. The method of claim 2,
The dimerization reactor effluent stream is supplied to an unreacted material separation column of the refining unit, and a top effluent stream from the unreacted material separation column is supplied to the dimerization reactor, and a bottom effluent stream comprising a product, a catalyst and a hydrocarbon-based solvent is catalyzed. fed to the separation column,
A method for producing adiponitrile, wherein the catalyst and hydrocarbon-based solvent are separated from the catalytic separation column overhead stream, and the bottom effluent stream containing the product is supplied to a thin film evaporation device. 4. The method of claim 3,
The catalytic separation column overheads stream is supplied to the catalyst recovery column as a stream comprising a catalyst and a hydrocarbon-based solvent,
A method for producing adiponitrile by recovering a catalyst and a hydrocarbon-based solvent from the bottom discharge stream from the catalyst recovery column and supplying it to a dimerization reactor. According to claim 1,
The product is a method for producing adiponitrile comprising dicyanobutene. According to claim 1,
The operating temperature of the thin film evaporation device is 160 ℃ to 270 ℃, the operating pressure is 20 torr to 500 torr adiponitrile manufacturing method. According to claim 1,
The operating temperature of the product purification column is 180 ℃ to 350 ℃ adiponitrile production method. According to claim 1,
The thin film evaporation device includes a body portion and a heating portion provided on the outer surface of the body portion in a form surrounding the outer peripheral surface of the body portion,
The heating unit includes a heating body having a space inside which a fluid can flow, an inlet provided on one side of the heating body and supplied with a heating medium, and an outlet provided on the other side of the heating body and through which the heating medium is discharged. Method for preparing adiponitrile. 9. The method of claim 8,
As the heating medium, the in-process stream is supplied through the inlet of the heating unit and discharged through the outlet. 10. The method of claim 9,
As the heating medium, a product purification column overheads stream is fed through the inlet of the heating unit and discharged through the outlet, a portion of the product purification column overheads stream passing through the heating unit is refluxed to the product purification column, and the remaining stream A method for producing adiponitrile by supplying it to a silver hydrogenation reactor. 9. The method of claim 8,
The heating medium discharged through the outlet of the heating unit is a method for producing adiponitrile that is supplied through the inlet of the heating unit after heat exchange with the in-process stream in the heat exchanger. 12. The method of claim 11,
The heating medium is a method for producing adiponitrile comprising at least one selected from the group consisting of thermal oil and steam. 12. The method of claim 11,
The heating medium discharged through the outlet of the heating unit is supplied through the inlet of the heating unit after heat exchange with the product purification column upper discharge stream in a heat exchanger.

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