Isopropylbenzene oxidation reaction system

Abstract

The utility model discloses a cumene oxidation reaction system and relates to the technical field of cumene production systems. The cumene oxidation reaction system is composed of a first preheater, a second preheater, a first oxidation reactor and a second oxidation reactor. Cumene is introduced through a first inlet of the first preheater, sequentially passes through the first preheater and the second preheater, then enters the first oxidation reactor and then flows to the second oxidation reactor, and materials after reaction are conveyed to a next treatment unit. Meanwhile, circulating materials of the second oxidation reactor and the first preheater form a loop, and the second preheater introduces a heat source and is communicated with the exhaust unit. According to the system, isopropylbenzene is preheated step by step through the first preheater and the second preheater, so that an ideal reaction temperature is achieved when materials enter the oxidation reactor, and the reaction efficiency and the product quality are remarkably improved; circulating materials of the second oxidation reactor are introduced into the first preheater, so that reaction heat is effectively recycled, external heat source consumption is reduced, and energy cost is reduced.

Description

Technical Field

[0001] This utility model relates to the technical field of cumene production systems, specifically to an cumene oxidation reaction system. Background Technology

[0002] Phenol and acetone are important chemical raw materials, widely used in synthetic resins, pharmaceuticals, pesticides, and fragrances. Currently, one method for preparing phenol and acetone in the chemical industry is the cumene process. This process mainly consists of five steps: alkylation (transposition alkylation), oxidation (concentration), hydrolysis, distillation, and recovery. Specifically, propylene and benzene react with a catalyst to produce cumene; subsequently, cumene is oxidized in the liquid phase to produce cumene hydroperoxide (CHP). CHP is then concentrated and decomposed with sulfuric acid to obtain phenol and acetone. Finally, a decomposition liquid containing a phenol / acetone mixture is obtained through resin neutralization, followed by distillation, separation, and purification to obtain the qualified product.

[0003] However, in the oxidation process of cumene, cumene reacts with oxygen to produce cumene hydroperoxide, an exothermic reaction that releases a large amount of heat. To avoid the risk of explosion caused by the high-temperature decomposition of cumene hydroperoxide (CHP), the heat generated during the reaction needs to be removed promptly. This process consumes a significant amount of energy, and this heat is not effectively recovered and utilized in current processes, resulting in resource waste. This energy waste not only increases production costs but also has a negative impact on the environment. Therefore, how to effectively recover and utilize the heat generated during the oxidation process is a pressing technical problem that needs to be solved in the current cumene process for producing phenol and acetone. Utility Model Content

[0004] To address the shortcomings of existing technologies, this invention provides an isopropylbenzene oxidation reaction system.

[0005] This utility model discloses a cumene oxidation reaction system, including a first preheater, a second preheater, a first oxidation reactor, and a second oxidation reactor. Isopropylbenzene is introduced into the first inlet of the first preheater, and the first outlet of the first preheater is connected to the first inlet of the second preheater. The first outlet of the second preheater is connected to the material inlet of the first oxidation reactor, and the material outlet of the first oxidation reactor is connected to the material inlet of the second oxidation reactor. The material outlet of the second oxidation reactor is connected to the next processing unit. The second inlet of the first preheater is connected to the circulation outlet of the second oxidation reactor, and the second outlet of the first preheater is connected to the circulation inlet of the second oxidation reactor. A heat source is introduced into the second inlet of the second preheater, and the second outlet of the second preheater is connected to an exhaust unit.

[0006] According to one embodiment of the present invention, a circulation pump is further provided on the pipeline connecting the second inlet of the first preheater and the circulation outlet of the second oxidation reactor. The inlet of the circulation pump is connected to the circulation outlet of the second oxidation reactor, and the outlet of the circulation pump is connected to the second inlet of the first preheater.

[0007] According to one embodiment of the present invention, a circulating cooler is further provided on the pipeline connecting the second outlet of the first preheater and the circulating inlet of the second oxidation reactor. The inlet of the circulating cooler is connected to the second outlet of the first preheater, and the outlet of the circulating cooler is connected to the circulating inlet of the second oxidation reactor.

[0008] According to one embodiment of the present invention, a first valve is provided on the pipeline through which cumene enters the first inlet of the first preheater, a second valve is provided on the pipeline through which the first outlet of the second preheater is connected to the material inlet of the first oxidation reactor, and a third valve is provided on the pipeline through which the heat source enters the second inlet of the second preheater.

[0009] According to one embodiment of the present invention, a flow meter is provided on the pipeline between the first outlet of the second preheater and the second valve.

[0010] According to one embodiment of the present invention, it further includes a third preheater, the first inlet of which isopropylbenzene raw material is introduced, the first outlet of the third preheater is connected to the first inlet of the first preheater, the second inlet of the third preheater is connected to the material outlet of the acetone crude distillation tower, and the second outlet of the third preheater is connected to the crude acetone reflux tank; a fourth valve is provided on the pipeline connecting the first outlet of the third preheater and the first inlet of the first preheater.

[0011] According to one embodiment of the present invention, the first preheater, the second preheater and the third preheater are shell-and-tube heat exchangers.

[0012] According to one embodiment of the present invention, it further includes a third oxidation reactor and a fourth oxidation reactor. The material inlet of the third oxidation reactor is connected to the material outlet of the second oxidation reactor, the material outlet of the third oxidation reactor is connected to the material inlet of the fourth oxidation reactor, and the material outlet of the fourth oxidation reactor is connected to the oxidation degassing tank.

[0013] According to one embodiment of the present invention, the operating temperature of the first oxidation reactor, the second oxidation reactor, the third oxidation reactor and the fourth oxidation reactor is 80~120℃.

[0014] According to one embodiment of the present invention, the reaction concentration in the first oxidation reactor is 9%, the reaction concentration in the second oxidation reactor is 14%, the reaction concentration in the third oxidation reactor is 19%, and the reaction concentration in the fourth oxidation reactor is 24%.

[0015] Compared with the prior art, the cumene oxidation reaction system of this utility model has the following advantages:

[0016] This invention relates to a cumene oxidation reaction system, which achieves step-by-step preheating of cumene through a first preheater and a second preheater. This ensures that the material reaches the ideal reaction temperature before entering the oxidation reactor, thereby improving reaction efficiency and product quality. Simultaneously, by introducing the recycled material from the second oxidation reactor into the first preheater, effective heat recovery and utilization are achieved, reducing the consumption of external heat sources.

[0017] In addition, the cumene oxidation reaction system is equipped with a circulating cooler to ensure that the temperature of the circulating material reaches the specified temperature, thus avoiding the risk of material decomposition and explosion caused by high temperature and ensuring the safety and stability of the reaction process.

[0018] In addition, the cumene oxidation reaction system is equipped with a third preheater to make full use of the waste heat from the acetone crude distillation column, further improving the system's energy utilization efficiency.

[0019] In addition, the cumene oxidation reaction system is equipped with a third and a fourth oxidation reactor, which further optimizes the oxidation reaction process and improves product quality and reaction efficiency. Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0021] Figure 1 This is a structural framework diagram of the cumene oxidation reaction system in the embodiment.

[0022] Explanation of reference numerals in the attached figures:

[0023] 1. First preheater; 2. Second preheater; 3. First oxidation reactor; 4. Second oxidation reactor; 5. First valve; 6. Second valve; 7. Circulating pump; 8. Circulating cooler; 9. Heat source; 10. Third valve; 11. Third preheater; 12. Fourth valve; 13. Acetone crude distillation tower; 14. Crude acetone reflux tank; 15. Flow meter. Detailed Implementation

[0024] The following illustrations disclose several embodiments of the present invention. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details should not be used to limit the present invention. That is, in some embodiments of the present invention, these practical details are not essential. In addition, for the sake of simplicity, some conventional structures and components will be shown in the illustrations in a simple schematic manner.

[0025] Furthermore, in this utility model, the use of terms such as "first" and "second" is for descriptive purposes only and does not specifically refer to any order or sequence, nor is it intended to limit the utility model. They are merely used to distinguish components or operations described with the same technical terms and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If a combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0026] See Figure 1 This embodiment provides a cumene oxidation reaction system, which consists of a first preheater 1, a second preheater 2, a first oxidation reactor 3, and a second oxidation reactor 4. Cumene is introduced into the first inlet of the first preheater 1 through a pipeline. A first valve 5 is installed on this pipeline to precisely control the flow rate of cumene, ensuring a stable feedstock flow into the system. The first outlet of the first preheater 1 is connected to the first inlet of the second preheater 2 through a pipeline, allowing the cumene, preheated by the first preheater 1, to flow smoothly into the second preheater 2 for further heating. The first outlet of the second preheater 2 is connected to the material inlet of the first oxidation reactor 3, and a second valve 6 is installed on the connecting pipeline to regulate the flow rate of the material supplied to the first oxidation reactor 3, ensuring a stable supply of the materials required for the reaction. The material outlet of the first oxidation reactor 3 is connected to the material inlet of the second oxidation reactor 4, and the material outlet of the second oxidation reactor 4 is connected to the next processing unit, thereby realizing the orderly reaction and flow of materials in the system, so that cumene can undergo oxidation reaction in the two oxidation reactors in sequence to generate the target product.

[0027] Simultaneously, a circulation loop is established between the first preheater 1 and the second oxidation reactor 4. The second inlet of the first preheater 1 is connected to the circulation outlet of the second oxidation reactor 4 via a pipeline, and a circulation pump 7 is installed on this pipeline. The inlet of the circulation pump 7 is connected to the circulation outlet of the second oxidation reactor 4, and the outlet of the circulation pump 7 is connected to the second inlet of the first preheater 1. Its function is to drive a portion of the oxidized liquid in the second oxidation reactor 4 to flow through the first preheater 1, transferring heat to the cumene flowing through the first preheater 1 through heat exchange, thereby achieving heat recycling and improving energy efficiency. The second outlet of the first preheater 1 is connected to the circulation inlet of the second oxidation reactor 4, and a circulation cooler 8 is installed on this pipeline. The inlet of the circulation cooler 8 is connected to the second outlet of the first preheater 1, and the outlet of the circulation cooler 8 is connected to the circulation inlet of the second oxidation reactor 4. Its function is to cool the returned material, ensuring that the temperature of the oxidized liquid returning to the second oxidation reactor 4 remains at a certain level. After heat exchange, the oxidizing liquid flowing through the first preheater 1 has dropped to a certain temperature. It is further cooled by the circulating cooler 8, so that the temperature of the oxidizing liquid returning to the second oxidation reactor 4 is controlled at 75~85℃. This maintains the reaction temperature in the second oxidation reactor 4 within a suitable range, ensuring that the oxidation reaction can proceed safely and stably.

[0028] In addition, the second inlet of the second preheater 2 is supplied with heat source 9, and the second outlet of the second preheater 2 is connected to the exhaust unit. The heat source 9 supplied to the second inlet of the second preheater 2 is low-pressure steam at 0.35 MPa. A third valve 10 is installed on the pipeline through which heat source 9 is supplied. By adjusting the opening of the third valve 10, the amount of low-pressure steam supplied can be precisely controlled to meet the heating requirements of the second preheater 2 for cumene.

[0029] In actual system operation, cumene first enters the first preheater 1 through a pipeline equipped with the first valve 5. In the first preheater 1, cumene undergoes sufficient heat exchange with the material returning from the second oxidation reactor 4, achieving preliminary preheating. The preheated cumene then flows into the second preheater 2 through a connecting pipeline. In the second preheater 2, with the help of low-pressure steam at 0.35 MPa, the cumene is further heated, reaching a material temperature of 85-89°C at the first outlet of the second preheater 2, thus raising the cumene to a suitable reaction temperature. The heated cumene then enters the first oxidation reactor 3 through a pipeline equipped with the second valve 6. In the first oxidation reactor 3, cumene undergoes an oxidation reaction under set reaction conditions. The oxidized liquid, after completing the first stage of oxidation, flows out from the material outlet of the first oxidation reactor 3 and enters the second oxidation reactor 4 to continue the oxidation reaction. After the reaction is completed in the second oxidation reactor 4, the oxidized liquid is transported from the material outlet of the second oxidation reactor 4 to the next processing unit for subsequent separation, purification, and other processes.

[0030] Meanwhile, some of the oxidized liquid in the second oxidation reactor 4 flows through the first preheater 1 under the action of the circulating pump 7. This oxidized liquid exchanges heat with the cumene flowing through the first preheater 1, transferring its own heat to the cumene and achieving heat recovery and utilization. After completing the heat exchange, the oxidized liquid is cooled down to 75~85℃ by the circulating cooler 8 and returns to the second oxidation reactor 4 to continue participating in the reaction, forming a complete material circulation and heat recovery system.

[0031] In this embodiment, a third preheater 11 can be added to the system to further improve energy efficiency. The first inlet of the third preheater 11 is used to introduce cumene raw material, and the first outlet of the third preheater 11 is connected to the first inlet of the first preheater 1. A fourth valve 12 is installed on this connecting pipeline to control the delivery of the cumene raw material, ensuring that the flow rate of the raw material entering the first preheater 1 meets the system operating requirements. The second inlet of the third preheater 11 is connected to the material outlet of the acetone crude distillation tower 13, and the second outlet is connected to the crude acetone reflux tank 14. In actual operation, when the acetone crude distillation tower 13 is working, some or all of the cumene raw material first enters the third preheater 11, where cumene undergoes efficient heat exchange with the material from the acetone crude distillation tower 13. On the one hand, cumene is preheated, reducing the burden on the subsequent heating processes in the first preheater 1 and the second preheater 2, and lowering energy consumption. On the other hand, the material in the acetone crude distillation tower 13 is cooled after heat exchange with cumene, making it easier for it to enter the crude acetone reflux tank 14 for storage or further processing. After heat exchange, the materials flow into their respective subsequent units according to their respective directions, continuing to participate in the entire production process.

[0032] It is worth noting that cumene first undergoes heat exchange in the first preheater 1 and then in the second preheater 2 before entering the first oxidation reactor 3. Only when the acetone crude distillation tower 13 is working does part or all of the cumene flow through the third preheater 11. This process design allows the system to flexibly adjust the material flow direction under different operating conditions, thereby improving energy utilization efficiency.

[0033] In this embodiment, the first preheater 1, the second preheater 2, and the third preheater 11 all adopt shell-and-tube heat exchangers. Shell-and-tube heat exchangers have advantages such as mature structure, high heat exchange efficiency, stable operation, and convenient maintenance, which can fully meet the requirements of this system for the heat exchange performance and stability of the preheater, ensuring that cumene can be effectively preheated to the appropriate reaction temperature.

[0034] To enable cumene to undergo a more complete oxidation reaction and improve the yield and purity of cumene hydroperoxide, this system may further include a third oxidation reactor (not shown in the figure) and a fourth oxidation reactor (not shown in the figure). The material inlet of the third oxidation reactor is connected to the material outlet of the second oxidation reactor 4, the material outlet of the third oxidation reactor is connected to the material inlet of the fourth oxidation reactor, and the material outlet of the fourth oxidation reactor is connected to the oxidation degassing tank.

[0035] The operating temperatures of the first oxidation reactor 3, the second oxidation reactor 4, the third oxidation reactor, and the fourth oxidation reactor are all strictly controlled within the range of 80~120℃. Within this temperature range, the cumene oxidation reaction can proceed stably with high efficiency, while effectively reducing the probability of side reactions and ensuring the yield and quality of the target product. Since cumene first reaches the first oxidation reactor 3, a higher operating temperature is required; the operating temperature of the first oxidation reactor 3 is 104~110℃.

[0036] Furthermore, the reaction concentration in the first oxidation reactor 3 was set at 9%, the second oxidation reactor 4 at 14%, the third oxidation reactor at 19%, and the fourth oxidation reactor at 24%. By rationally setting the reaction concentrations in different oxidation reactors, the reaction process was optimized, allowing the material to react fully in each reactor and gradually increasing the yield and purity of cumene hydroperoxide. The reacted material was then transported to an oxidation degassing tank for further processing, such as removing gases generated during the reaction, preparing for subsequent separation and purification processes.

[0037] In addition, a flow meter 15 is installed on the pipeline between the first outlet of the second preheater 2 and the second valve 6. The flow meter 15 can monitor the flow rate of the material entering the first oxidation reactor 3 in real time to adjust the opening of the second valve 6, and also ensure the stability of the flow rate of the material entering the first oxidation reactor 3, thereby maintaining the stability and consistency of the oxidation reaction, improving the controllability of the reaction process and the stability of product quality.

[0038] The cumene oxidation reaction system of this embodiment, through the above-described structural design and operation mode, achieves the following results after testing:

[0039] In terms of energy conservation, the amount of low-pressure steam used in the second preheater has been greatly reduced from 10~12T / h to 0~2T / h; at the same time, the amount of circulating water in the circulating cooler has been significantly reduced from 400~600T / h to 0~200T / h, effectively reducing production costs and energy consumption.

[0040] In terms of equipment maintenance, the frequency of high-pressure flushing of the circulating cooler has been significantly reduced from approximately once every 2 years to once every 5 years, which reduces the workload and cost of equipment maintenance and improves the service life of the equipment and the stability of system operation.

[0041] This cumene oxidation reaction system achieves significant technical benefits through the rational design of the preheater and oxidation reactor configuration and their connection relationships. The system includes multiple preheaters and oxidation reactors, and by optimizing heat recovery and utilization, it improves reaction efficiency and energy utilization efficiency while reducing operating and equipment maintenance costs.

[0042] Specifically, the system achieves stepwise preheating of cumene by setting up a first preheater and a second preheater, ensuring that the material reaches the ideal reaction temperature before entering the oxidation reactor, thereby improving reaction efficiency and product quality. Simultaneously, by introducing the recycled material from the second oxidation reactor into the first preheater, effective heat recovery and utilization are achieved, reducing the consumption of external heat sources. Furthermore, the system incorporates a circulating cooler to strictly control the temperature of the recycled material, avoiding the risk of material decomposition and explosion due to high temperatures, and ensuring the safety and stability of the reaction process.

[0043] Furthermore, the system incorporates valves on the heat source pipeline of the second preheater. By adjusting the valve opening, the flow rate of the heat source can be flexibly controlled, thereby optimizing the preheating effect. Simultaneously, a flow meter is installed on the material outlet pipeline of the second preheater to monitor the material flow rate in real time, ensuring the stability of the reaction conditions. These designs not only improve the system's flexibility and controllability but also further optimize energy utilization efficiency.

[0044] In terms of system expansion, the energy utilization efficiency of the system was further improved by adding a third preheater to fully utilize the waste heat of the acetone crude distillation column. Furthermore, the oxidation reaction process was further optimized by adding a third and a fourth oxidation reactor, improving product quality and reaction efficiency.

[0045] In summary, this cumene oxidation reaction system, by optimizing the configuration and connection relationship of the preheater and oxidation reactor, achieves effective heat recovery and utilization, improves reaction efficiency and energy utilization efficiency, while reducing operating costs and equipment maintenance costs, and ensures the safety and stability of the reaction process.

[0046] The above description is merely an embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this utility model should be included within the scope of the claims of this utility model.

Claims

1. A cumene oxidation reaction system, characterized in that, The reactor includes a first preheater (1), a second preheater (2), a first oxidation reactor (3), and a second oxidation reactor (4). Isopropylbenzene is introduced into the first inlet of the first preheater (1). The first outlet of the first preheater (1) is connected to the first inlet of the second preheater (2). The first outlet of the second preheater (2) is connected to the material inlet of the first oxidation reactor (3). The material outlet of the first oxidation reactor (3) is connected to the material inlet of the second oxidation reactor (4). The material outlet of the second oxidation reactor (4) is connected to the next processing unit. The second inlet of the first preheater (1) is connected to the circulation outlet of the second oxidation reactor (4). The second outlet of the first preheater (1) is connected to the circulation inlet of the second oxidation reactor (4). A heat source (9) is introduced into the second inlet of the second preheater (2). The second outlet of the second preheater (2) is connected to the exhaust unit.

2. The cumene oxidation reaction system according to claim 1, characterized in that, A circulation pump (7) is also provided on the pipeline connecting the second inlet of the first preheater (1) and the circulation outlet of the second oxidation reactor (4). The inlet of the circulation pump (7) is connected to the circulation outlet of the second oxidation reactor (4), and the outlet of the circulation pump (7) is connected to the second inlet of the first preheater (1).

3. The cumene oxidation reaction system according to claim 2, characterized in that, A circulating cooler (8) is also provided on the pipeline connecting the second outlet of the first preheater (1) to the circulating inlet of the second oxidation reactor (4). The inlet of the circulating cooler (8) is connected to the second outlet of the first preheater (1), and the outlet of the circulating cooler (8) is connected to the circulating inlet of the second oxidation reactor (4).

4. The cumene oxidation reaction system according to claim 1, characterized in that, A first valve (5) is provided on the pipeline through which the cumene enters the first inlet of the first preheater (1), a second valve (6) is provided on the pipeline through which the first outlet of the second preheater (2) is connected to the material inlet of the first oxidation reactor (3), and a third valve (10) is provided on the pipeline through which the heat source (9) enters the second inlet of the second preheater (2).

5. The cumene oxidation reaction system according to claim 4, characterized in that, A flow meter (15) is installed on the pipeline between the first outlet of the second preheater (2) and the second valve (6).

6. The cumene oxidation reaction system according to claim 1, characterized in that, It also includes a third preheater (11), the first inlet of which isopropylbenzene raw material is introduced, the first outlet of which is connected to the first inlet of the first preheater (1), the second inlet of which is connected to the material outlet of the acetone crude distillation tower (13), and the second outlet of which is connected to the crude acetone reflux tank (14); a fourth valve (12) is provided on the pipeline connecting the first outlet of the third preheater (11) to the first inlet of the first preheater (1).

7. The cumene oxidation reaction system according to claim 6, characterized in that, The first preheater (1), the second preheater (2) and the third preheater (11) are shell-and-tube heat exchangers.

8. The cumene oxidation reaction system according to claim 1, characterized in that, It also includes a third oxidation reactor and a fourth oxidation reactor. The material inlet of the third oxidation reactor is connected to the material outlet of the second oxidation reactor (4). The material outlet of the third oxidation reactor is connected to the material inlet of the fourth oxidation reactor. The material outlet of the fourth oxidation reactor is connected to the oxidation degassing tank.

9. The cumene oxidation reaction system according to claim 8, characterized in that, The operating temperature of the first oxidation reactor (3), the second oxidation reactor (4), the third oxidation reactor and the fourth oxidation reactor is 80~120℃.

10. The cumene oxidation reaction system according to claim 9, characterized in that, The reaction concentration in the first oxidation reactor (3) is 9%, the reaction concentration in the second oxidation reactor (4) is 14%, the reaction concentration in the third oxidation reactor is 19%, and the reaction concentration in the fourth oxidation reactor is 24%.

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