A continuous production method and device of isobutylbenzene

Abstract

The application belongs to the technical field of organic synthesis, and particularly relates to a continuous production method and device of isobutylbenzene. The continuous production method comprises the following steps: continuously feeding raw material A and raw material B into a reactor to perform a side chain alkylation reaction, the raw material A comprises toluene and a catalyst, the raw material B comprises propylene, continuously discharging the obtained reaction liquid containing isobutylbenzene, performing solid-liquid separation to obtain a solid and a first liquid, and recycling the solid catalyst; performing first rectification on the first liquid to obtain a second liquid and a first gas component; recycling the first gas component propylene; performing second rectification on the second liquid to obtain a third liquid and a second gas component; recycling the second gas component toluene; and performing third rectification on the third liquid, and liquefying to obtain isobutylbenzene. Compared with a traditional tank production process, the application has low reaction pressure, the reaction temperature is easy to adjust, the occurrence of a side reaction is reduced, and the application is more efficient and stable.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of organic synthesis, and particularly relates to a continuous production method and device of isobutylbenzene. BACKGROUND

[0002] Ibuprofen is a non-steroidal anti-inflammatory drug, which has peripheral and central analgesic effect. It has been proved that ibuprofen is an extremely effective antipyretic and analgesic drug for both adults and children, and has less side effects. Isobutylbenzene is an important material for producing ibuprofen, and has a structural formula of C6H5-CH2-CH(CH3)2, which is a colorless liquid, insoluble in water, soluble in organic solvents such as ethanol and diethyl ether, has an aromatic odor, and has a boiling point of about 170-172℃.

[0003] At present, the production method of isobutylbenzene is a kettle type batch reaction, in which methylbenzene, liquid propylene and a catalyst are mixed in a batch type reaction kettle at one time, and then heated to perform side chain alkylation to obtain isobutylbenzene. After the reaction is completed, the product is unloaded, and the whole process has obvious discontinuity and periodicity. The production efficiency of this traditional technology is relatively low, and the yield per unit time is low. The process control is difficult, and fluctuations are prone to occur. It is difficult to keep the quality of different batches of products consistent, and the stability of the product quality is poor, which is not suitable for large-scale production. In addition, the equipment utilization rate and energy consumption are not ideal, which will cause resource waste and cost increase. Moreover, the recovery of the catalyst and raw materials is relatively difficult, and the raw material conversion rate is low, which is usually only about 40%. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a continuous production method and device of isobutylbenzene. The continuous production method of isobutylbenzene provided by the present application has high raw material conversion rate, less impurities generated in the reaction process, and high product yield.

[0005] The present application provides a continuous production method of isobutylbenzene, which comprises the following steps:

[0006] The raw material A and the raw material B are continuously fed into the reactor to perform side chain alkylation reaction to obtain a reaction liquid containing isobutylbenzene; the raw material A comprises methylbenzene and a catalyst, and the raw material B comprises propylene;

[0007] The reaction liquid containing isobutylbenzene is continuously unloaded, and solid-liquid separation is performed to obtain a solid and a first liquid, and the solid comprises recovered catalyst and is used for side chain alkylation reaction;

[0008] The first liquid is subjected to first rectification to obtain a second liquid and a first gas component; the first gas component mainly comprises recovered propylene and is used for side chain alkylation reaction;

[0009] The second feed liquid is subjected to a second rectification to obtain a third feed liquid and a second gas component; the second gas component is mainly recovered toluene and is used in the side chain alkylation reaction.

[0010] The third feed liquid is subjected to a third rectification, and the obtained third gas component is liquefied to obtain isobutylbenzene.

[0011] Preferably, the catalyst is a mixture of alkali metal and alkali metal carbonate, and the mass ratio of the alkali metal to the alkali metal carbonate in the catalyst is 0.5-1.5:1-3.

[0012] Preferably, the mass ratio of the toluene to the catalyst is 95-99.5:0.5-5.

[0013] Preferably, the molar ratio of the propylene to the toluene is 4-9:1-5.

[0014] Preferably, the temperature of the side chain alkylation reaction is 165-255℃.

[0015] Preferably, the pressure of the side chain alkylation reaction is 1-5 MPa.

[0016] Preferably, the residence time of the raw material A and the raw material B is 15-30 min.

[0017] The application further provides a continuous production device of isobutylbenzene, which comprises a reaction kettle.

[0018] A first storage tank and a second storage tank in communication with a feed inlet of the reaction kettle, respectively;

[0019] A hydrocyclone in communication with a discharge outlet of the reaction kettle;

[0020] A first rectification tower in communication with an overflow outlet of the hydrocyclone, and a bottom flow outlet of the hydrocyclone being in communication with the reaction kettle;

[0021] A second rectification tower in communication with a tower kettle discharge outlet of the first rectification tower, and a tower top discharge outlet of the first rectification tower being in communication with the first storage tank;

[0022] A third rectification tower in communication with a tower kettle discharge outlet of the second rectification tower, and a tower top discharge outlet of the second rectification tower being in communication with the second storage tank.

[0023] Preferably, a delivery pump is further in communication between the discharge outlet of the reaction kettle and the hydrocyclone.

[0024] Preferably, a first compressor is further in communication between the tower top discharge outlet of the first rectification tower and the first storage tank; and a second compressor is further in communication between the tower top discharge outlet of the second rectification tower and the second storage tank.

[0025] Compared with the prior art, the application has the following beneficial effects:

[0026] The application provides a continuous production method of isobutylbenzene, comprising the following steps: continuously feeding raw material A and raw material B into a reactor to perform a side chain alkylation reaction, to obtain a reaction liquid containing isobutylbenzene; the raw material A comprises toluene and a catalyst, and the raw material B comprises propylene; continuously discharging the reaction liquid containing isobutylbenzene, performing solid-liquid separation, to obtain a solid and a first liquid, and the solid comprises recovered catalyst and is used for the side chain alkylation reaction; performing first rectification on the first liquid, to obtain a second liquid and a first gas component; the first gas component mainly comprises recovered propylene and is used for the side chain alkylation reaction; performing second rectification on the second liquid, to obtain a third liquid and a second gas component; the second gas component mainly comprises recovered toluene and is used for the side chain alkylation reaction; performing third rectification on the third liquid, liquefying the obtained third gas component, and obtaining isobutylbenzene.

[0027] The continuous production method of isobutylbenzene can realize uninterrupted operation of the reaction process through continuous feeding and discharging operations, can reduce the occurrence of side reactions such as self-polymerization of propylene, and can reduce the generation of impurities. Moreover, the continuous production method of the application can recover unreacted propylene and toluene through the rectification system after the reaction, can recycle the unreacted raw materials, can improve the raw material conversion rate and product yield, can significantly improve the resource utilization rate, and can reduce raw material waste.

[0028] The application adopts a continuous synthesis method, the reaction time can be precisely controlled, the feeding and discharging time can be controlled, the generation amount of impurities can be reduced, and the purity and yield of isobutylbenzene can be improved. The application can reasonably control the residence time, temperature, pressure and catalyst dosage of reactants, ensure the full reaction of the reactants, and reduce the discharge of unreacted raw materials.

[0029] The application realizes the continuity of the production process, effectively improves the production efficiency, shortens the production cycle, and can quickly and massively supply market demand. At the same time, the continuous and stable reaction environment is conducive to precisely controlling the reaction conditions, so as to ensure that the product quality is highly consistent and stable. The application has important significance in terms of resource utilization efficiency and energy saving, can reduce production costs and the influence on the environment, and brings a new revolution to the production of isobutylbenzene, and promotes the related industry to develop in a more efficient, high-quality and sustainable direction. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to make the technical solutions in the embodiments of the present application or the prior art clearer, the accompanying drawings needed in the embodiments will be briefly introduced. Obviously, the accompanying drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 A schematic diagram of the equipment for continuous production of isobutylbenzene in the embodiments; wherein S01-propylene storage tank, S02-toluene storage tank, R01-isobutylbenzene synthesis kettle, P01-conveying pump, F01-hydrocyclone, T01-distillation column 1, T02-distillation column 2, T03-distillation column 3, C01-compressor 1, C02-compressor 2;

[0032] Figure 2 A result graph of the influence of different catalyst dosages, reaction temperatures, reaction pressures and residence times on product yield. DETAILED DESCRIPTION

[0033] The present application provides a continuous production method of isobutylbenzene, comprising the following steps:

[0034] Sustainedly feeding raw material A and raw material B into a reactor to perform a side chain alkylation reaction to obtain a reaction liquid containing isobutylbenzene; the raw material A comprises toluene and a catalyst, and the raw material B comprises propylene;

[0035] Sustainedly discharging the reaction liquid containing isobutylbenzene to perform a solid-liquid separation to obtain a solid and a first liquid, and the solid comprises a recovered catalyst which is reused in the side chain alkylation reaction;

[0036] Performing a first distillation on the first liquid to obtain a second liquid and a first gas component; the first gas component is mainly recovered propylene which is reused in the side chain alkylation reaction;

[0037] Performing a second distillation on the second liquid to obtain a third liquid and a second gas component; the second gas component is mainly recovered toluene which is reused in the side chain alkylation reaction;

[0038] Performing a third distillation on the third liquid, and liquefying the obtained third gas component to obtain isobutylbenzene.

[0039] In the present application, unless otherwise specified, the materials and equipment used are commercially available products in the art.

[0040] In the present application, unless otherwise specified, the materials and equipment used are commercially available products in the art.

[0041] In the present application, the catalyst is preferably a mixture of alkali metal and alkali metal carbonate, and can be a mixture of potassium and sodium carbonate, or a mixture of sodium and potassium carbonate; the mass ratio of alkali metal to alkali metal carbonate in the catalyst is preferably 0.5-1.5:1-3, and more preferably 0.8:1.2.

[0042] In the present application, the mass ratio of toluene to catalyst is preferably 95-99.5:0.5-5, and more preferably 96-99:1-4, and can be 99:1, 98:2 or 97:3. The content of catalyst in the raw material A is preferably 1wt%-3wt%, and can be 1wt%, 2wt% or 3wt%.

[0043] In the present application, the molar ratio of propylene to toluene is preferably 4-9:1-5, and can be 1:1.

[0044] In the present application, the temperature of the side-chain alkylation reaction is preferably 165-255℃, and more preferably 180-250℃, and can be 180℃, 190℃, 195℃, 200℃, 210℃, 225℃, 240℃ or 250℃.

[0045] In the present application, the pressure of the side-chain alkylation reaction is preferably 1-5MPa, and can be 2MPa, 3MPa, 4MPa or 5MPa.

[0046] In the present application, the residence time of the raw material A and the raw material B is preferably 15-30min, and can be 20min or 25min.

[0047] After obtaining the reaction liquid containing isobutylbenzene, the present application continuously discharges the reaction liquid containing isobutylbenzene, and performs solid-liquid separation to obtain solid and first liquid, wherein the solid includes recovered catalyst, which is reused in the side-chain alkylation reaction.

[0048] In the present application, the purpose of the solid-liquid separation is to separate the catalyst from the liquid, and then recover the catalyst and reuse it in the side-chain alkylation reaction.

[0049] The present application performs first rectification on the first liquid to obtain second liquid and first gaseous component; the first gaseous component is mainly recovered propylene, which is reused in the side-chain alkylation reaction.

[0050] In the present application, the pressure of the rectifying tower used in the first rectification is preferably 3.5 MPa, the top temperature is preferably 90-100℃, and the bottom temperature is preferably 105-115℃. The temperature and pressure of the first rectification can make propylene gasify (the boiling point of propylene is about 95℃ under 3.5 MPa), while other components remain in the liquid, realizing the separation of propylene. The first rectification preferably further comprises liquefying the obtained first gas component.

[0051] The present application performs second rectification on the second liquid, obtaining a third liquid and a second gas component; the second gas component is mainly recovered toluene, which is used for side chain alkylation reaction.

[0052] In the present application, the top temperature of the rectifying tower used in the second rectification is preferably 110-115℃, and the bottom temperature is preferably 120-130℃. The temperature of the second rectification can make toluene gasify (the boiling point of toluene is about 110.6℃ under normal pressure), while other components remain in the remaining liquid, realizing the separation of toluene. The second rectification preferably further comprises liquefying the obtained second gas component.

[0053] The present application performs third rectification on the third liquid, liquefies the obtained third gas component, and obtains isobutylbenzene.

[0054] In the present application, the top temperature of the rectifying tower used in the third rectification is preferably 165-170℃, and the bottom temperature is preferably 175-185℃. The temperature of the third rectification can make isobutylbenzene gasify (the boiling point of isobutylbenzene is about 169℃ under normal pressure), while other high-boiling impurities remain in the remaining liquid, realizing the separation of isobutylbenzene.

[0055] The present application also provides a continuous production device of isobutylbenzene, comprising a reaction kettle;

[0056] A first storage tank and a second storage tank in communication with the feed inlet of the reaction kettle, respectively;

[0057] A hydrocyclone in communication with the discharge outlet of the reaction kettle;

[0058] A first rectifying tower in communication with the overflow outlet of the hydrocyclone, and the underflow outlet of the hydrocyclone is in communication with the reaction kettle;

[0059] A second rectifying tower in communication with the discharge outlet of the column of the first rectifying tower, and the top discharge outlet of the first rectifying tower is in communication with the first storage tank;

[0060] A third rectifying tower in communication with the discharge outlet of the column of the second rectifying tower, and the top discharge outlet of the second rectifying tower is in communication with the second storage tank.

[0061] In this invention, the reactor is used for the synthesis of isobutylbenzene, the first storage tank is used to store propylene, and the second storage tank is used to store toluene.

[0062] In this invention, a transfer pump is preferably connected between the discharge port of the reactor and the hydrocyclone to transport materials. The hydrocyclone separates the liquid feed from the catalyst, which is then reused in the synthesis of isobutylbenzene.

[0063] In this invention, a first compressor is preferably connected between the top outlet of the first distillation column and the first storage tank for liquefying propylene; a second compressor is preferably connected between the top outlet of the second distillation column and the second storage tank for liquefying toluene.

[0064] To further illustrate the present invention, the continuous production method and apparatus for isobutylbenzene provided by the present invention will be described in detail below with reference to the accompanying drawings and embodiments, but these should not be construed as limiting the scope of protection of the present invention.

[0065] In Examples 1-3 of this invention, raw material A comprises: 98 wt% toluene, 0.8 wt% potassium and 1.2 wt% sodium carbonate, wherein potassium and sodium carbonate are catalysts; raw material B: propylene; the capacity of the synthesis reactor is 5000 L.

[0066] In embodiments of the present invention, the devices used are such as Figure 1 As shown, S01-propylene storage tank, S02-toluene storage tank, R01-isobutylbenzene synthesis reactor, P01-transfer pump, F01-cyclone separator, T01-distillation column 1, T02-distillation column 2, T03-distillation column 3, C01-compressor 1, C02-compressor 2.

[0067] Example 1

[0068] according to Figure 1After installing and commissioning the equipment, toluene and catalyst (catalyst content in the mixture is 2 wt%) are mixed as raw material A, and propylene is used as raw material B. The mixture is fed into the synthesis reactor (R01) at a toluene to propylene molar ratio of 1:1. When the reactor reaches half its volume, the temperature inside is heated to 195°C using heat transfer oil, and the reaction begins. The pressure inside the reactor is 3 MPa. After 30 minutes of reaction, the feed and discharge ports of the synthesis reactor are simultaneously opened, with a material residence time of 30 minutes. The material from the discharge port is sent to the hydrocyclone separator (F01) via a transfer pump (P01). Upon entering the hydrocyclone separator, the catalyst and the feed liquid are separated, allowing for secondary recovery and utilization of the catalyst. The feed liquid is sent to distillation column 1 (T01), which operates at a pressure of 3.5 MPa, with a top temperature of 90–100°C and a bottom temperature of 105–115°C. Propylene, the component with the lowest boiling point in the feed liquid, is collected from the top of the column, liquefied by a compressor (CO1), and then recovered to a propylene storage tank (S01) for reuse. The remaining feed liquid is sent to distillation column 2 (T02), which has a top temperature of 110–115°C and a bottom temperature of 120–130°C. Toluene in the feed liquid is collected from the top of the column, liquefied by a compressor (CO2), and then recovered to a toluene storage tank (S02) for reuse. The remaining liquid was sent to distillation column 3 (T03) to separate isobutylbenzene from high-boiling impurities. The top temperature of distillation column 3 was 165-170℃ and the bottom temperature was 175-185℃. Finally, isobutylbenzene product was obtained at the top of T03. The reaction lasted for 8 hours.

[0069] In this example, the toluene conversion rate was 72%, and the isobutylbenzene yield was 39.5%.

[0070] Example 2

[0071] The difference from Example 1 is that the temperature inside the synthesis vessel is heated to 210°C and the pressure inside the synthesis vessel is 5 MPa.

[0072] In this example, the toluene conversion rate was 60.5%, and the isobutylbenzene yield was 35.2%.

[0073] Example 3

[0074] The difference from Example 1 is that the temperature inside the synthesis vessel is heated to 180°C and the pressure inside the synthesis vessel is 1 MPa.

[0075] In this example, the toluene conversion rate was 48.6%, and the isobutylbenzene yield was 33.6%.

[0076] The appropriate combination of temperature and moderate pressure in Example 1 provided the highest conversion and yield, indicating that higher temperature and pressure are not necessarily better for this reaction. By comparing the three examples, it can be seen that the combination of moderate temperature and moderate pressure is the most effective, while excessively high temperature and pressure (Example 2) and lower temperature and pressure (Example 3) are less effective.

[0077] Example 4

[0078] Orthogonal experiments were conducted to investigate the effects of reaction temperature, reaction pressure, catalyst dosage (potassium and sodium carbonate mass ratio maintained at 2:3), and material residence time on the synthesis of isobutylbenzene. Except for the variables in the table, the other conditions were the same as in Example 1. The settings and results are shown in Tables 1 and 2.

[0079] Table 1 Effects of reaction temperature and reaction pressure on the synthesis of isobutylbenzene

[0080]

[0081]

[0082] Table 2 Effects of catalyst dosage and residence time on isobutylbenzene synthesis

[0083]

[0084] The effects of different catalyst dosages, reaction temperatures, reaction pressures, and residence times on product yields are as follows: Figure 2 As shown, the product yield gradually increases with increasing catalyst dosage, reaching its highest point when the catalyst content in feed A reaches 2 wt%. Subsequently, the product yield begins to decrease with further increases in catalyst content. Similarly, the product yield gradually increases with increasing reaction temperature, reaching its highest point at 195℃, and then begins to decrease with further increases in reaction temperature. The product yield also gradually increases with increasing reaction pressure, reaching its highest point at 3 MPa, and then begins to decrease with further increases in reaction pressure. Finally, the product yield gradually increases with increasing residence time, but the increase slows down after 30 minutes. Therefore, the optimal residence time is determined to be 30 minutes.

[0085] Compared with existing batch production technologies for isobutylbenzene, the continuous batch production method employed in this invention offers significant advantages. Existing batch production technologies suffer from discontinuous operation, relatively low efficiency, cumbersome processes, and difficulty in precise control. In contrast, the continuous batch production method of this invention achieves an uninterrupted process, improving production efficiency and output, while enabling more precise control of various process parameters to ensure product quality stability and consistency. This continuous production mode effectively reduces downtime and changeover time in intermediate stages, greatly enhancing overall production efficiency and successfully overcoming many drawbacks of existing batch production technologies. Furthermore, this invention utilizes continuous production, resulting in lower reaction pressures compared to traditional batch reactions, and unreacted raw materials can be recycled.

[0086] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, not all embodiments. People can obtain other embodiments based on the present invention without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A continuous production method for isobutylbenzene, characterized in that, Includes the following steps: Raw material A and raw material B are continuously fed into a reactor for a side-chain alkylation reaction to obtain a reaction solution containing isobutylbenzene; raw material A includes toluene and a catalyst, and raw material B includes propylene; the content of the catalyst in raw material A is 2wt%~3wt%; the molar ratio of propylene to toluene is 1:1; the temperature of the side-chain alkylation reaction is 195℃; the pressure of the side-chain alkylation reaction is 3MPa; the residence time of raw material A and raw material B is 30min; the catalyst is a mixture of alkali metal and alkali metal carbonate, and the mass ratio of alkali metal to alkali metal carbonate in the catalyst is 0.5~1.5:1~3; The reaction liquid containing isobutylbenzene is continuously discharged and subjected to solid-liquid separation to obtain a solid and a first liquid. The solid includes the recovered catalyst, which is reused in the side-chain alkylation reaction. The first liquid feed is subjected to a first distillation to obtain a second liquid feed and a first gaseous component; the first gaseous component is mainly recovered propylene, which is reused in the side-chain alkylation reaction; The second feed liquid is subjected to a second distillation to obtain a third feed liquid and a second gaseous component; the second gaseous component is mainly recovered toluene, which is reused in the side-chain alkylation reaction; The third liquid is subjected to a third distillation, and the resulting third gaseous component is liquefied to obtain isobutylbenzene; The continuous production apparatus used in the continuous production method of isobutylbenzene includes a reaction vessel; A first storage tank and a second storage tank are respectively connected to the feed inlet of the reactor; A hydrocyclone separator connected to the outlet of the reactor; A first distillation column is connected to the overflow outlet of the hydrocyclone, and the underflow outlet of the hydrocyclone is connected to the reactor; A second distillation column is connected to the bottom outlet of the first distillation column, and the top outlet of the first distillation column is connected to the first storage tank. A third distillation column is connected to the bottom outlet of the second distillation column, and the top outlet of the second distillation column is connected to the second storage tank.

2. The continuous production method according to claim 1, characterized in that, A transfer pump is also connected between the discharge port of the reactor and the hydrocyclone separator.

3. The continuous production method according to claim 1 or 2, characterized in that, A first compressor is connected between the top outlet of the first distillation column and the first storage tank; a second compressor is connected between the top outlet of the second distillation column and the second storage tank.

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