Diisononyl phthalate production device and production method

Abstract

The invention provides a production device and a production method of diisononyl phthalate. The diisononyl phthalate production device comprises a feeding system, at least one esterification reaction kettle and a dealcoholization tower which are sequentially connected, the operation temperature of the esterification reaction kettle is 200-250 DEG C; and / or the operation pressure of the esterification reaction kettle is 0-0.05 MPaG; and / or the operation pressure of the dealcoholization tower is 6-12 KPaA. According to the invention, after the high-temperature liquid in the esterification reaction kettle enters the dealcoholization tower, the isononyl alcohol with a lower boiling point and water are quickly vaporized and then transferred into a subsequent separation system, so that the dealcoholization and dehydration purposes are realized under the condition that an external heat source is not arranged.

Description

Technical Field

[0001] This invention belongs to the field of plasticizer technology, specifically relating to an apparatus for producing diisononyl phthalate. Furthermore, this invention also relates to a method for producing diisononyl phthalate. Background Technology

[0002] Plasticizers are the largest category of plastic processing aids in terms of both production capacity and consumption. They are widely used in plastic products such as toys and building materials, accounting for over 60% of the total output of plastic additives. Diisononyl phthalate (DINP) is a commonly used phthalate plasticizer, synthesized through the esterification reaction of phthalic anhydride and isononyl alcohol. The reaction equation is as follows:

[0003] (1) Monoesterification of phthalic anhydride

[0004]

[0005] (2) Monoester esterification

[0006]

[0007] In existing technologies, isononol that has not participated in the chemical reaction is removed using a falling film evaporator. However, the process of removing alcohol using a falling film evaporator requires the introduction of a heat source (i.e., steam), resulting in high energy consumption.

[0008] Therefore, developing a diisononyl phthalate production apparatus that can both reduce the energy consumption of external heat sources during the de-alcoholization process and achieve de-alcoholization has become an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0009] The purpose of this invention is to solve the problems existing in the prior art and provide a diisononyl phthalate production device. The reactor discharge is a high-temperature liquid. By utilizing the temperature and pressure of the reactor discharge itself, it enters the de-alcoholizing tower for low-pressure flash evaporation. Isononyl alcohol and water are vaporized and separated, thereby achieving the purpose of de-alcoholization and dehydration, saving the consumption of external heat sources.

[0010] This invention is achieved through the following technical solution:

[0011] One of the objectives of this invention is to provide a diisononyl phthalate production apparatus, comprising a feeding system, at least one esterification reactor, and a dealcoholization tower connected in sequence.

[0012] The operating temperature of the esterification reactor is 200–250°C; and / or

[0013] The operating pressure of the esterification reactor is 0–0.05 MPaG; and / or

[0014] The operating pressure of the dealcoholization tower is 6–12 kPaA.

[0015] In a preferred embodiment of the present invention, the esterification reactor includes a feed line and a discharge line;

[0016] Preferably, the number of esterification reactors is three, including a first esterification reactor, a second esterification reactor, and a third esterification reactor;

[0017] The feed line of the first esterification reactor is connected to the feed system, and the lower discharge line of the first esterification reactor is connected to the feed line of the second esterification reactor.

[0018] The feed line of the second esterification reactor is connected to the lower discharge line of the first esterification reactor, and the lower discharge line of the second esterification reactor is connected to the feed line of the third esterification reactor.

[0019] The feed line of the third esterification reactor is connected to the lower discharge line of the second esterification reactor, and the lower discharge line of the third esterification reactor is connected to the alcohol removal tower.

[0020] More preferably,

[0021] The operating temperature of the first esterification reactor 2 is 200–215℃; and / or

[0022] The operating temperature of the second esterification reactor 3 is 220–235℃; and / or

[0023] The operating temperature of the second esterification reactor 3 is 235–250℃.

[0024] In a preferred embodiment of the present invention, the apparatus further includes an alcohol recovery tower; the esterification reactor further includes an upper discharge pipeline; the alcohol recovery tower is connected to the upper discharge pipeline of the esterification reactor;

[0025] Preferably, the operating pressure of the alcohol recovery tower is 0.03 to 0.06 MPaG.

[0026] In a preferred embodiment of the present invention, the alcohol recovery tower is provided with an alcohol outlet pipeline, which is connected to the feed system and the esterification reactor respectively.

[0027] Preferred,

[0028] A first alcohol inlet pipeline is provided between the alcohol outlet pipeline and the first esterification reactor, and a first valve is provided on the first alcohol inlet pipeline; and / or

[0029] A second alcohol inlet pipeline is provided between the alcohol outlet pipeline and the second esterification reactor, and a second valve is provided on the second alcohol inlet pipeline; and / or

[0030] A third alcohol inlet pipeline is provided between the alcohol outlet pipeline and the third esterification reactor, and a third valve is provided on the third alcohol inlet pipeline; and / or

[0031] A fourth alcohol inlet pipeline is provided between the alcohol outlet pipeline and the feeding system, and a fourth valve is provided on the fourth alcohol inlet pipeline.

[0032] More preferably,

[0033] The esterification conversion rate in the first esterification reactor is 85–93%; and / or

[0034] The esterification conversion rate in the second esterification reactor is 93-97%; and / or

[0035] The esterification conversion rate in the third esterification reactor is over 97%.

[0036] In a preferred embodiment of the present invention, the alcohol recovery tower includes a first packing zone, and a first inlet is provided on the side wall of the alcohol recovery tower; in the vertical direction, the first inlet is located below the first packing zone; the esterification reactor is connected to the first inlet;

[0037] Preferred,

[0038] The alcohol recovery tower also includes a second packing zone located below the first packing zone, and the side wall of the alcohol recovery tower is also provided with a second inlet; in the vertical direction, the second inlet is located below the second packing zone, and the first inlet is located between the second packing zone and the second packing zone; the upper discharge pipeline of the esterification reactor is selectively connected to the first inlet and the second inlet;

[0039] More preferably,

[0040] The downstream esterification reactor is connected to the second inlet.

[0041] In a preferred embodiment of the present invention, the apparatus further includes a first separation system connected to the alcohol recovery tower; and / or

[0042] The apparatus further includes a second separation system connected to the dealcoholization tower.

[0043] In a preferred embodiment of the present invention, the esterification reactor is provided with a heating steam inlet pipeline.

[0044] The second objective of this invention is to provide a method for producing diisononyl phthalate using a diisononyl phthalate production apparatus employing one of the objectives of this invention, comprising the following steps:

[0045] S1: The reactants enter the first esterification reactor from the feeding system and undergo esterification reaction in the first esterification reactor to obtain the first steam and the first high-temperature liquid; the first steam is transferred to the alcohol recovery tower and the first high-temperature liquid is transferred to the second esterification reactor;

[0046] S2: The first high-temperature liquid undergoes an esterification reaction in the second esterification reactor to obtain the second vapor and the second high-temperature liquid; the second vapor is transferred to the alcohol recovery tower, and the second high-temperature liquid is transferred to the third esterification reactor;

[0047] S3: The second high-temperature liquid undergoes an esterification reaction in the third esterification reactor to obtain a third vapor and a third high-temperature liquid; the third high-temperature liquid is then post-treated to obtain diisononyl phthalate.

[0048] In a preferred embodiment of the present invention

[0049] The esterification conversion rate in the first esterification reactor is 85–93%; and / or

[0050] The esterification conversion rate in the second esterification reactor is 93-97%; and / or

[0051] The esterification conversion rate in the third esterification reactor is over 97%;

[0052] Preferred,

[0053] The esterification conversion rate in the first esterification reactor is 86-88%; and / or

[0054] The esterification conversion rate in the second esterification reactor is 94–96%; and / or

[0055] The esterification conversion rate in the third esterification reactor is over 99%.

[0056] In a preferred embodiment of the present invention

[0057] In the first, second, and third esterification reactors, the operating temperature is 200–250°C; and / or

[0058] In the first, second, and third esterification reactors, the operating pressure is 0–0.05 MPaG; and / or

[0059] In the alcohol recovery tower, the operating pressure is 0.03–0.06 MPaG; and / or

[0060] The operating pressure in the dealcoholization tower is 6–12 kPaA.

[0061] Preferred,

[0062] In the first esterification reactor, the operating temperature is 200–215°C; and / or

[0063] In the second esterification reactor, the operating temperature is 220–235°C; and / or

[0064] In the third esterification reactor, the operating temperature is 235–250℃.

[0065] Compared with the prior art, the beneficial effects of the present invention are:

[0066] 1. In this invention, the operating temperature of each esterification reactor is 200-250℃ and the operating pressure is 0-0.05MPaG; the operating pressure of the dealcoholization tower is 6-12KPaA; therefore, after the high-temperature liquid in the esterification reactor enters the dealcoholization tower, the isononol and water with lower boiling points are rapidly vaporized and then transferred to the subsequent separation system, thus achieving the purpose of dealcoholization and dehydration without setting an external heat source.

[0067] 2. In this invention, the flow rate of isononol returning to each esterification reactor can be adjusted by controlling the first, second, and third valves. When the esterification reaction conversion rate is low, the first, second, and third valves are selectively opened, allowing the isononol in the alcohol recovery tower to be directly returned to each esterification reactor, increasing the alcohol-acid ratio and improving the esterification reaction conversion rate. When the esterification reaction conversion rate is normal, the first, second, and third valves can be selectively closed, allowing the isononol in the alcohol recovery tower to be sent back to the feed system. This reduces the load on the subsequent dealcoholization tower system, lowering operating costs, and also reduces the amount of isononol added.

[0068] 3. In this invention, the operating pressure of the dealcoholization tower is 6-12 kPaA. After the esterification reactor discharge, the product is directly fed into the dealcoholization tower for negative pressure flash evaporation. After the product is discharged from the bottom of the dealcoholization tower, the purity of DINP reaches 97%. Attached Figure Description

[0069] Figure 1 This is a structural diagram of the diisononyl phthalate production apparatus of the present invention;

[0070] In the diagram, 1-feeding system; 2-first esterification reactor; 3-second esterification reactor; 4-third esterification reactor; 5-alcohol recovery tower; 6-first separation system; 7-de-alcoholization tower; 8-second separation system; 9-first valve; 10-second valve; 11-third valve; 12-fourth valve. Detailed Implementation

[0071] The present invention will now be described in further detail with reference to the accompanying drawings:

[0072] Example 1

[0073] like Figure 1As shown, this embodiment provides a diisononyl phthalate production apparatus, including a feeding system 1, an esterification reactor, an alcohol recovery tower 5, and a dealcoholization tower 7. The esterification reactor is equipped with a feed line, an upper discharge line, and a lower discharge line. The number of esterification reactors is at least one, preferably three. When there is only one esterification reactor, its feed line is connected to the feeding system 1, its upper discharge line is connected to the alcohol recovery tower 5, and its lower discharge line is connected to the dealcoholization tower 7.

[0074] The upstream esterification reactor has its feed line connected to the feed system 1, its upper discharge line connected to the alcohol recovery tower 5, and its lower discharge line connected to the feed line of the next-level esterification reactor. The midstream esterification reactor has its feed line connected to the lower discharge line of the previous-level esterification reactor, its upper discharge line connected to the alcohol recovery tower 5, and its lower discharge line connected to the feed line of the next-level esterification reactor. The downstream esterification reactor has its feed line connected to the lower discharge line of the previous-level esterification reactor, its upper discharge line connected to the alcohol recovery tower 5, and its lower discharge line connected to the dealcoholization tower 7.

[0075] When there are three esterification reactors, for ease of description, the three esterification reactors are named sequentially as First Esterification Reactor 2, Second Esterification Reactor 3, and Third Esterification Reactor 4. The feed line of First Esterification Reactor 2 is connected to Feed System 1, the upper discharge line of First Esterification Reactor 2 is connected to Alcohol Recovery Tower 5, and the lower discharge line of First Esterification Reactor 2 is connected to the feed line of Second Esterification Reactor 3. The feed line of Second Esterification Reactor 3 is connected to the lower discharge line of First Esterification Reactor 2, the upper discharge line of Second Esterification Reactor 3 is connected to Alcohol Recovery Tower 5, and the lower discharge line of Second Esterification Reactor 3 is connected to the feed line of Third Esterification Reactor 4. The feed line of Third Esterification Reactor 4 is connected to the lower discharge line of Second Esterification Reactor 3, the upper discharge line of Third Esterification Reactor 4 is connected to Alcohol Recovery Tower 5, and the lower discharge line of Third Esterification Reactor 4 is connected to De-alcoholization Tower 7. The reactants (phthalic anhydride and isononol) are fed sequentially from the feed system 1 into three esterification reactors connected in series: the first esterification reactor 2, the second esterification reactor 3, and the third esterification reactor 4.

[0076] In a preferred embodiment of the present invention, the esterification reactor is provided with a heating steam inlet pipeline ( Figure 1(Not shown in the diagram), heating steam can be introduced into the esterification reactor through the heating steam inlet pipeline to control the reaction temperature at 200-250°C. Specifically, in this embodiment, heating steam is introduced into the first esterification reactor 2, the second esterification reactor 3, and the third esterification reactor 4 to control the reaction temperature of all three at 200-250°C. During the reaction, rising steam (isononyl alcohol, water) will form at the top of the three esterification reactors, and high-temperature liquid (DINP, alcohol, water) will form at the bottom.

[0077] In a preferred embodiment of the present invention, the reaction temperature of the first esterification reactor 2 is 200–215°C, the reaction temperature of the second esterification reactor 3 is 220–235°C, and the reaction temperature of the third esterification reactor 4 is 235–250°C. It should be noted that the first esterification reactor 2, the second esterification reactor 3, and the third esterification reactor 4 are all sealed with nitrogen, and the pressure inside each reactor is maintained within 0–0.05 MPaG. Furthermore, the reaction temperature of the first esterification reactor 2, the second esterification reactor 3, and the third esterification reactor 4 can also be achieved by heating the jackets installed on their outer sides.

[0078] The alcohol recovery tower 5 is vertically taller than the first esterification reactor 2, the second esterification reactor 3, and the third esterification reactor 4. Each of the first esterification reactors 2, 3, and 4 has an upper discharge pipeline connected to the alcohol recovery tower 5. During the esterification reaction, rising steam (isononanol and water) is generated at the top of each of the three reactors, and this rising steam enters the alcohol recovery tower 5 through the upper discharge pipeline.

[0079] The alcohol recovery tower 5 includes a first packing zone, and a first inlet is provided on the side wall of the alcohol recovery tower 5; vertically, the first inlet is located below the first packing zone; the esterification reactor is connected to the first inlet. Preferably, the alcohol recovery tower 5 further includes a second packing zone located below the first packing zone, and a second inlet is also provided on the side wall of the alcohol recovery tower 5; vertically, the second inlet is located below the second packing zone, and the first inlet is located between the second packing zone and the second packing zone; the upper discharge pipeline of the esterification reactor is optionally connected to the first inlet and the second inlet. It should be noted that the first packing zone and the second packing zone are both conventional packing materials in the art, and the present invention is not limited thereto. The operating pressure of the alcohol recovery tower 5 is 0.03–0.06 MPaG.

[0080] In a preferred embodiment of the present invention, the first inlet is connected via pipelines to the upper discharge pipelines of the first esterification reactor 2 and the second esterification reactor 3. Specifically, the rising vapor (isononanol and water) generated at the top of the first and second esterification reactors 2 and 3 enters the alcohol recovery tower 5 through the first inlet between the first and second packing zones; then it moves towards the first packing zone and exchanges heat there. After heat exchange, the higher-boiling-point isononanol is converted into a liquid phase and, under gravity, passes through the second packing zone into the bottom of the alcohol recovery tower 5; the water vapor in the rising vapor enters the top of the alcohol recovery tower 5 and then enters the first separation system 6, which is connected to the top of the alcohol recovery tower 5.

[0081] In a preferred embodiment of the present invention, the second inlet is connected to the upper discharge pipeline of the third esterification reactor 4. That is, the rising steam (isononanol and water) formed at the top of the third esterification reactor 4 enters the lower part of the second packing zone in the alcohol recovery tower 5 through the second inlet; then it moves towards the second packing zone and exchanges heat there. After the first heat exchange is completed, part of the isononanol in the rising steam is converted into a liquid phase, and under the action of gravity, it passes through the second packing zone and enters the bottom of the alcohol recovery tower 5. The remaining rising steam continues to move towards the first packing zone and exchanges heat there. After the heat exchange is completed, the isononanol therein is converted into a liquid phase, and under the action of gravity, it leaves the first packing zone and passes through the second packing zone, finally entering the bottom of the alcohol recovery tower 5; the water vapor in the rising steam enters the top of the alcohol recovery tower 5, and then enters the first separation system 6 connected to the top of the alcohol recovery tower 5.

[0082] In a preferred embodiment of the present invention, the alcohol recovery tower 5 is further provided with an alcohol outlet pipeline, which is connected to the feed system 1, the first esterification reactor 2, the second esterification reactor 3, and the third esterification reactor 4, respectively. Specifically, in this embodiment, a first alcohol inlet pipeline is provided between the alcohol outlet pipeline and the first esterification reactor 2, and a first valve 9 is provided on the first alcohol inlet pipeline; a second alcohol inlet pipeline is provided between the alcohol outlet pipeline and the second esterification reactor 3, and a second valve 10 is provided on the second alcohol inlet pipeline; a third alcohol inlet pipeline is provided between the alcohol outlet pipeline and the third esterification reactor 4, and a third valve 11 is provided on the third alcohol inlet pipeline; a fourth alcohol inlet pipeline is provided between the alcohol outlet pipeline and the feed system 1, and a fourth valve 12 is provided on the fourth alcohol inlet pipeline. It should be noted that the fourth valve 12 is always in the open state.

[0083] The first esterification reactor 2 is equipped with a sampling port. Operators sample the product DINP from the first esterification reactor 2 and determine the DINP yield. (It should be noted that each esterification reactor is equipped with a lower discharge line, and the sampling port is located on this lower discharge line.) After the measurement is completed, the real-time conversion rate of the first esterification reactor 2 is calculated. The real-time conversion rate of the first esterification reactor 2 is calculated based on the DINP content and residual raw material content in the reactants. The real-time conversion rate of the first esterification reactor 2 is compared with the esterification reaction conversion rate threshold (85-93%) of the first esterification reactor 2. If the real-time conversion rate of the first esterification reactor 2 is less than the esterification reaction conversion rate threshold, the first valve 9 is opened, allowing isononol from the bottom of the alcohol recovery tower 5 to enter the first esterification reactor 2, increasing the alcohol-acid ratio of the reactants and improving the esterification reaction conversion rate. After a period of reaction, the first esterification reactor 2 is sampled again, and its real-time conversion rate is calculated. If the real-time conversion rate of the first esterification reactor 2 reaches the esterification reaction conversion rate threshold of the first esterification reactor 2, then the first valve 9 is closed, so that the isononol in the bottom of the alcohol recovery tower 5 no longer enters the first esterification reactor 2.

[0084] Similarly, the second esterification reactor 3 and the third esterification reactor 4 are also equipped with sampling ports, and their real-time conversion rates also need to be controlled. The control method is the same as that of the first esterification reactor 2. The only differences are: first, controlling the real-time conversion rates of the second esterification reactor 3 and the third esterification reactor 4 requires controlling the second valve 10 and the third valve 11 respectively; second, the esterification conversion rate thresholds of the second esterification reactor 3 and the third esterification reactor 4 are different from those of the first esterification reactor 2.

[0085] In a preferred embodiment of the present invention, the esterification conversion rate thresholds of the first esterification reactor 2, the second esterification reactor 3, and the third esterification reactor 4 are 85-93%, 93-97%, and 97% or more, respectively. Preferably, the esterification conversion rate thresholds of the first esterification reactor 2, the second esterification reactor 3, and the third esterification reactor 4 are 86-88%, 94-96%, and 99% or more, respectively.

[0086] In summary, by controlling the first valve 9, the second valve 10, and the third valve 11, the isononol in the bottom of the alcohol recovery tower 5 can be returned to the first esterification reactor 2, the second esterification reactor 3, and the third esterification reactor 4, respectively. This allows the real-time conversion rates of the first esterification reactor 2, the second esterification reactor 3, and the third esterification reactor 4 to reach their respective esterification reaction conversion rate thresholds, minimizing the volume of each esterification reactor, reducing the load on the alcohol recovery tower 5, reducing the amount of isononol used, and improving the purity of DINP. Here, "minimizing volume" specifically refers to, for a series-connected batch reactor, after determining the feed rate, the number of reactors, and the conversion rate, rationally allocating the conversion rate of each reactor. This essentially involves allocating the empty time of each reactor, which also determines the required volume of each reactor. This invention minimizes the volume of each esterification reactor by controlling the real-time conversion rates of the first esterification reactor 2, the second esterification reactor 3, and the third esterification reactor 4 to reach their respective esterification reaction conversion rate thresholds.

[0087] The product in the esterification reactor is diisononyl phthalate, whose boiling point is much higher than that of isononol and water. Therefore, it is in a liquid state in the esterification reactor and eventually settles at the bottom of the third esterification reactor 4. The bottom of the third esterification reactor 4 is connected to the dealcoholization tower 7. Since the discharge from the third esterification reactor 4 is a high-temperature liquid (DINP, isononol, and water), the temperature is approximately 235–250°C, and the pressure is approximately 0–0.05 MPaG. The operating pressure of the dealcoholization tower 7 is 6–12 kPaA. Therefore, by utilizing the temperature of the high-temperature liquid itself and the pressure drop after entering the dealcoholization tower 7, the isononol and water with lower boiling points in the high-temperature liquid are rapidly vaporized, i.e., flash evaporation is achieved. The vaporized isononol and water rise through the packing section in the dealcoholization tower 7 and enter the second separation system 8, which is connected to the top of the dealcoholization tower 7, ultimately achieving the purpose of de-alcoholization and dehydration. During the de-alcoholization and dehydration process in the dealcoholization tower 7, no external heat source is required, saving the consumption of external heat sources. Preferably, the bottom of the dealcoholization tower 7 is equipped with an external coil, which can provide an additional heat source to the dealcoholization tower 7 in cold weather, ensuring the separation effect of DINP from isononol and water.

[0088] Example 2

[0089] This embodiment provides a method for producing diisononyl phthalate, including the following steps:

[0090] S3: The second high-temperature liquid undergoes an esterification reaction in the third esterification reactor to obtain a third vapor and a third high-temperature liquid; the third high-temperature liquid undergoes post-processing to obtain diisononyl phthalate.

[0091] S1: The reactants (phthalic anhydride and isononol) enter the first esterification reactor 2 from the feed system 1 and undergo esterification reaction to obtain first vapor and first high-temperature liquid. Preferably, the reaction temperature is controlled at 200-215°C, the reaction pressure at 0-0.05 MPaG, and the esterification reaction conversion rate is 85-93%. During the esterification reaction, first vapor (isononol and water) is formed at the top of the first esterification reactor 2, and high-temperature liquid (DINP, alcohol, and water) is formed at the bottom. The first vapor (isononol and water) enters the alcohol recovery tower 5 through the upper discharge pipeline and the first inlet of the first esterification reactor 2, and the first high-temperature liquid (DINP, alcohol, and water) enters the second esterification reactor 3 through the lower discharge pipeline of the first esterification reactor 2. The operating pressure of the alcohol recovery tower 5 and the operating pressure of the dealcoholization tower 7 are controlled at 6-12 kPaA.

[0092] S2: The first high-temperature liquid (DINP, alcohol, water) entering the second esterification reactor 3 continues the esterification reaction in the second esterification reactor 3, yielding a second vapor and a second high-temperature liquid; preferably, the reaction temperature is controlled at 220–235°C, the reaction pressure at 0–0.05 MPaG, and the esterification reaction conversion rate is 93–97%. During the esterification reaction, a second vapor and a second high-temperature liquid are still formed, which enter the alcohol recovery tower 5 and the third esterification reactor 4 respectively, which will not be elaborated here. The operating pressure of the alcohol recovery tower 5 is controlled at 6–12 kPaA, and the operating pressure of the dealcoholization tower 7 is controlled at 6–12 kPaA.

[0093] S3: The second high-temperature liquid (DINP, alcohol, water) entering the third esterification reactor 4 continues the esterification reaction in the third esterification reactor 4, yielding third vapor and third high-temperature liquid; preferably, the reaction temperature is controlled at 235-250℃, the reaction pressure at 0-0.05 MPaG, and the esterification reaction conversion rate is above 97%. During the esterification reaction, third vapor and third high-temperature liquid are still formed; the third vapor (isononanol, water) enters the alcohol recovery tower 5 through the upper discharge pipeline and the second inlet of the third esterification reactor 4, and the third high-temperature liquid (DINP, alcohol, water) enters the dealcoholization tower 7 through the lower discharge pipeline of the third esterification reactor 4. The operating pressure of the alcohol recovery tower 5 is controlled at 0.03-0.06 MPaG; the operating pressure of the dealcoholization tower is controlled at 6-12 kPaA.

[0094] In S1 to S3, the first steam, the second steam, and the third steam successively enter the alcohol recovery tower 5. After heat exchange in the first packed zone and / or the second packed zone, water vapor (located at the top of the alcohol recovery tower 5) and isononol (located at the top of the alcohol recovery tower 5) in the gaseous phase are obtained. The water vapor enters the first separation system 6, and the isononol in the liquid phase is used to return to the feed system 1 or to adjust the esterification reaction conversion rate of each esterification reactor.

[0095] In S1 to S3, the opening and closing of the first valve 9, the second valve 10, and the third valve 11 are adjusted according to the esterification reaction conversion rates of the first esterification reactor 2, the second esterification reactor 3, and the third esterification reactor 4, so that the conversion rates of the three reactors reach the preset range.

[0096] S4: The third high-temperature liquid entering the dealcoholization tower 7 undergoes flash evaporation under its own temperature and pressure difference. After isononol and water vaporize, they enter the second separation system 8. The reaction products, which are still in the liquid phase, are neutralized and washed with water to obtain the DINP product.

[0097] Experimental Example 1

[0098] Phthalic anhydride and isononol were fed into the first esterification reactor 2 via a self-feeding system 1 (wherein the phthalic anhydride mass flow rate was 45 kg / h and the isononol mass flow rate was 115 kg / h). The temperature of the first esterification reactor 2 was controlled at 210℃, the pressure at 0.05 MPaG, and the esterification conversion rate at 87%. Note that isononol vapor and water vapor will enter the alcohol recovery tower 5 during the reaction.

[0099] It should be noted that this invention is a continuous reaction, not a batch reaction, therefore there is no need to limit the reaction time of each esterification reactor. After the continuous reaction, the liquid phase of the first esterification reactor 2 is transferred to the second esterification reactor 3, and the temperature of the second esterification reactor 3 is controlled at 230°C, the pressure at 0.05 MPaG, and the esterification conversion rate at 95%. Note that during the reaction, isononol vapor and water vapor will enter the alcohol recovery tower 5.

[0100] After continuous reaction, the liquid phase from the second esterification reactor 3 is transferred to the third esterification reactor 4. The temperature of the third esterification reactor 4 is controlled at 245℃, the pressure at 0.05 MPaG, and the esterification conversion rate is 99%. This indicates that isononol vapor and water vapor will enter the alcohol recovery tower 5 during the reaction.

[0101] Throughout the continuous reaction process, the operating pressure of alcohol recovery tower 5 is 0.05 MPaG; the operating pressure of dealcoholization tower 7 is 8 kPaA.

[0102] After continuous reaction, the reaction product from the second esterification reactor 3 is transferred to the dealcoholization tower 7. After dealcoholization in the dealcoholization tower 7, it is neutralized and washed with water to obtain the DINP product. The DINP content in this DINP product is 97%.

[0103] Comparative Example 1

[0104] This comparative example is basically the same as Example 1, except that the esterification reaction conversion rate in the first esterification reactor 2 is 60%. Compared with Example 1, the amount of gas entering the alcohol recovery tower 5 increased by 27%, and the amount of alcohol in the bottom of the alcohol recovery tower 5 increased by 32%; the amount of material entering the dealcoholization tower 7 (including DINP, isononanol, water, etc.) decreased by 7%, resulting in a DINP content of 95% in the DINP product.

[0105] Comparative Example 2

[0106] This comparative example is basically the same as Example 1, except that the esterification conversion rate in the first esterification reactor 2 is 60% and the esterification conversion rate in the second esterification reactor 3 is 75%. Compared with Example 1, the amount of gas entering the alcohol recovery tower 5 increased by 35%, and the amount of alcohol in the bottom of the alcohol recovery tower 5 increased by 42%; the amount of material entering the dealcoholization tower 7 decreased by 8%, resulting in a DINP content of 92% in the DINP product.

[0107] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0108] In the description of this invention, unless otherwise stated, the terms "upper," "lower," "left," "right," "inner," "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0109] The above technical solution is only one embodiment of the present invention. For those skilled in the art, based on the principles disclosed in the present invention, it is easy to make various types of improvements or modifications, and not limited to the technical solutions described in the specific embodiments of the present invention. Therefore, the foregoing description is only a preferred option and is not restrictive.

Claims

1. A device for producing diisononyl phthalate, characterized in that: The device comprises a feeding system, at least one esterification reactor, and a dealcoholization tower connected in sequence. The operating temperature of the esterification reactor is 200-250℃; and / or The operating pressure of the esterification reactor is 0-0.05 MPaG; and / or The operating pressure of the dealcoholization tower is 6-12 KPaA.

2. The device for producing diisononyl phthalate according to claim 1, wherein: The esterification reactor comprises a feeding line and a lower discharge line; Preferably, the number of the esterification reactors is three, including a first esterification reactor, a second esterification reactor, and a third esterification reactor; The feeding line of the first esterification reactor is connected with the feeding system, and the lower discharge line of the first esterification reactor is connected with the feeding line of the second esterification reactor; The feeding line of the second esterification reactor is connected with the lower discharge line of the first esterification reactor, and the lower discharge line of the second esterification reactor is connected with the feeding line of the third esterification reactor; The feeding line of the third esterification reactor is connected with the lower discharge line of the second esterification reactor, and the lower discharge line of the third esterification reactor is connected with the dealcoholization tower; More preferably, The operating temperature of the first esterification reactor 2 is 200-215℃; and / or The operating temperature of the second esterification reactor 3 is 220-235℃; and / or The operating temperature of the third esterification reactor 3 is 235-250℃. The device further comprises an alcohol recovery tower; the esterification reactor further comprises an upper discharge line; the alcohol recovery tower is connected with the upper discharge line of the esterification reactor; 3. The diisnonyl phthalate production apparatus according to claim 1 or 2, characterized by: Preferably, the operating pressure of the alcohol recovery tower is 0.03-0.06 MPaG.

4. The device for producing diisononyl phthalate according to claim 3, wherein: The alcohol recovery tower is provided with an alcohol outlet line, and the alcohol outlet line is connected with the feeding system and the esterification reactor respectively; Preferably, A first alcohol inlet line is arranged between the alcohol outlet line and the first esterification reactor, and a first valve is arranged on the first alcohol inlet line; and / or A second alcohol inlet line is arranged between the alcohol outlet line and the second esterification reactor, and a second valve is arranged on the second alcohol inlet line; and / or A third alcohol inlet line is arranged between the alcohol outlet line and the third esterification reactor, and a third valve is arranged on the third alcohol inlet line; and / or A fourth alcohol inlet line is arranged between the alcohol outlet line and the feeding system, and a fourth valve is arranged on the fourth alcohol inlet line; More preferably, The esterification conversion rate of the first esterification reactor is 85-93%; and / or The esterification conversion rate of the second esterification reactor is 93-97%; and / or The esterification conversion rate of the third esterification reactor is more than 97%.

5. The device for producing diisononyl phthalate according to claim 3, wherein: The alcohol recovery tower comprises a first packing zone, and the sidewall of the alcohol recovery tower is provided with a first inlet; in the vertical direction, the first inlet is located below the first packing zone; the esterification reactor is connected with the first inlet; Preferably, ​ The alcohol recovery column further comprises a second packing zone below the first packing zone, and the side wall of the alcohol recovery column is further provided with a second inlet; in the vertical direction, the second inlet is below the second packing zone, and the first inlet is between the second packing zone and the second packing zone; the upper discharge pipeline of the esterification reactor is selectively connected with the first inlet and the second inlet; More preferably, The esterification reactor at the most downstream is connected with the second inlet.

6. The diisononyl phthalate production device according to claim 3, characterized in that: The device further comprises a first separation system connected with the alcohol recovery column; and / or The device further comprises a second separation system connected with the dealcoholization tower.

7. The diisononyl phthalate production device according to claim 1 or 2, characterized in that: The esterification reactor is provided with a heating steam inlet pipeline.

8. A process for the production of di-isononyl phthalate, characterized in that: The diisononyl phthalate production device according to any one of claims 2-7 is used; preferably comprising the following steps S1: the reactant material enters the first esterification reactor from the feeding system and performs esterification reaction in the first esterification reactor to obtain first steam and first high-temperature liquid; the first steam is transferred into the alcohol recovery column, and the first high-temperature liquid is transferred into the second esterification reactor; S2: the first high-temperature liquid performs esterification reaction in the second esterification reactor to obtain second steam and second high-temperature liquid; the second steam is transferred into the alcohol recovery column, and the second high-temperature liquid is transferred into the third esterification reactor; S3: the second high-temperature liquid performs esterification reaction in the third esterification reactor to obtain third steam and third high-temperature liquid; the third high-temperature liquid is subjected to post-treatment to obtain diisononyl phthalate.

9. The production method according to claim 8, characterized in that: The esterification conversion rate of the first esterification reactor is 85-93%; and / or The esterification conversion rate of the second esterification reactor is 93-97%; and / or The esterification conversion rate of the third esterification reactor is more than 97%; More preferably, The esterification conversion rate of the first esterification reactor is 86-88%; and / or The esterification conversion rate of the second esterification reactor is 94-96%; and / or The esterification conversion rate of the third esterification reactor is more than 99%.

10. The production method according to claim 8, characterized in that: The operating temperature in the first esterification reactor, the second esterification reactor and the third esterification reactor is 200-250℃; and / or The operating pressure in the first esterification reactor, the second esterification reactor and the third esterification reactor is 0-0.05 MPaG; and / or The operating pressure in the alcohol recovery column is 0.03-0.06 MPaG; and / or The operating pressure in the dealcoholization tower is 6-12 KPaA; More preferably, The operating temperature in the first esterification reactor is 200-215℃; and / or The operating temperature in the second esterification reactor is 220-235℃; and / or The operating temperature in the third esterification reactor is 235-250℃.

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