Production method and system of tetracyclododecene

Abstract

The invention provides a production method and system of tetracyclododecene. The production method comprises the following steps: feeding a norbornene solution of dicyclopentadiene and gasified norbornene into a spray reactor, and reacting in the spray reactor to obtain a reaction product; the molar ratio of the norbornene to the dicyclopentadiene is (5-9): 1; buffering and depressurizing the reaction product to obtain reaction product liquid; and rectifying the reaction product liquid to respectively obtain norbornene and tetracyclododecene. The invention also provides a production system of tetracyclododecene. According to the production method, the spray reactor is used for reaction, so that the rate of converting the DCPD into the TCD can be remarkably improved, and the conversion rate of the DCPD and the selectivity of the TCD are improved.

Description

Technical Field

[0001] This invention relates to the field of preparation of tetracyclododecene, and more particularly to a method and system for producing tetracyclododecene. Background Technology

[0002] The synthesis of cyclic olefin copolymers / polymers (COC / COP) combines advantages such as low density, low hygroscopicity, high transparency, high heat resistance, high refractive index, and excellent processability. These amorphous thermoplastic polymers have attracted significant attention in industry and academia in recent years and are commonly used in the manufacture of pharmaceuticals, high-end optical components, and advanced coating materials. Tetracyclododecene is a key monomer in the preparation of COC / COP.

[0003] The synthesis of tetracyclododecene is commonly achieved through two methods: one involves reacting ethylene with dicyclopentadiene, which depolymerizes to cyclopentadiene at high temperatures. Cyclopentadiene then reacts with ethylene to form norbornene, which in turn reacts with cyclopentadiene to generate tetracyclododecene. The other method directly reacts norbornene with dicyclopentadiene, which depolymerizes to cyclopentadiene at high temperatures. Cyclopentadiene then reacts with norbornene to generate tetracyclododecene. The former method involves higher production pressure and often generates excessive amounts of norbornene (NB), and is commonly used in the co-production of norbornene (TCD). In the latter method, it is difficult to simultaneously improve reaction efficiency and reduce polymers: dicyclopentadiene (DCPD) and the depolymerized CPD are prone to self-polymerization to form trimer TCPD and polymers. In order to improve reaction efficiency, increasing the concentration of reactants will easily increase the generation of polymers, affecting the long-term stability and safety of the production equipment; if the concentration of reactants is reduced to suppress side reactions, the cost of solvent recovery will increase.

[0004] Japanese patent application JP3991650B2 discloses a method for simultaneously producing NB and TCD. Ethylene, CPD and / or DCPD and NB are continuously supplied to a reaction apparatus and reacted by heating. The reaction mixture is subjected to gas-liquid separation to separate unreacted ethylene and the liquid reaction mixture, and the separated ethylene is contacted with a solvent to transfer the NB contained in the ethylene into the solvent and separate it. The ethylene is recycled back to the reaction apparatus. After contact with ethylene, the solvent is mixed with the liquid reaction mixture, and a fraction containing NB, TCD, and solvent is separated from the mixture. A portion of the NB is then separated and recovered and recycled back to the reaction apparatus while heating. However, this patent simply manufactures and distills two products, failing to address the issue of controlling the ratio of tetracyclododecene and norbornene, and also failing to address the problem of polymer formation.

[0005] Chinese patent application CN115433053A discloses a method for the co-production of tetracyclododecene and norbornene. The method involves reacting a dicyclopentadiene solution with ethylene in a tubular reactor to obtain the co-product of tetracyclododecene and norbornene. This method eliminates the need for NB preparation, directly reacting dicyclopentadiene and ethylene using specific process parameters to simultaneously produce TCD and NB. The crude product contains 47.68% NB, 43.03% TCD, and only 1.02% byproducts. Atmospheric distillation of the crude product yields NB with a purity of over 99.8%, and further vacuum distillation yields TCD with a purity of over 99.5%. This co-production method simplifies the production process, eliminates the NB preparation step, and significantly reduces equipment investment, energy consumption, and unit consumption, resulting in very low costs. However, it does not address the issue of controlling the production ratio of NB and TCD and cannot produce NB independently.

[0006] Chinese patent application CN117602998A discloses a method for preparing norbornene and tetracyclododecene, which involves adding an inert solvent to ethylene and dicyclopentadiene, reducing reaction pressure and temperature, and extending residence time. Compared to previous technologies, this method has lower equipment investment and safety risks, and reducing the reaction temperature can also prevent pipeline blockage. However, this patent only reduces energy consumption in the reactor area; introducing an inert solvent increases energy consumption in the distillation area, and extending the residence time and reducing the reaction temperature also reduces the production efficiency of tetracyclododecene.

[0007] Chinese patent application CN112592248A provides a method that uses only norbornene and dicyclopentadiene as raw materials, without using any inert solvents, thus increasing product yield. It does not use ethylene gas or other olefins, resulting in high yield and improved process economy. However, it does not consider the self-polymerization side reaction of dicyclopentadiene at high concentrations and the byproducts generated by this self-polymerization.

[0008] The existing technologies mentioned above focus on solving the problem of preventing backmixing in gas-liquid mass transfer within the reactor or simultaneously producing NB and TCD to address the byproduct issue. However, the problem of removing already generated TCD by distillation remains unresolved, leading to a decrease in NB production. Furthermore, the current reaction methods result in excessively long residence times and low reaction efficiency. Summary of the Invention

[0009] To overcome the above problems, the present invention aims to provide a method and system for producing tetracyclododecene. This production method, by using a spray reactor, can significantly increase the rate of DCPD to TCD conversion, and improve the conversion rate of DCPD and the selectivity of TCD.

[0010] To achieve the above objectives, the present invention provides a method for producing tetracyclododecene, the method comprising:

[0011] A solution of dicyclopentadiene and norbornene and vaporized norbornene are fed into a spray reactor to react and obtain the reaction product; the molar ratio of norbornene to dicyclopentadiene is 5-9:1.

[0012] The reaction product was buffered and depressurized to obtain a liquid reaction product.

[0013] The reaction product liquid was distilled to obtain norbornene and tetracyclododecene, respectively.

[0014] In the aforementioned production method, the norbornene (NB) solution of dicyclopentadiene (DCPD) serves as the liquid phase, while vaporized norbornene acts as the gas phase. The reaction between these two phases in the spray reactor is a two-phase reaction, and the formation of droplets increases the gas-liquid contact area, thereby increasing the reaction rate. Furthermore, in the synthesis reaction of tetracyclododecene, the reaction of dicyclopentadiene feed droplets in a norbornene atmosphere favors the formation of tetracyclododecene. Simultaneously, the reaction between tetracyclododecene and norbornene or dicyclopentadiene in a single droplet is inhibited, preventing further polymer formation. Therefore, this invention significantly improves the rate of dicyclopentadiene conversion to tetracyclododecene by spraying the dicyclopentadiene norbornene solution in a norbornene atmosphere within a spray reactor, thereby increasing the conversion rate of dicyclopentadiene and the selectivity of tetracyclododecene.

[0015] In the above production method, the polymerization reaction of tetracyclododecene and dicyclopentadiene and the reaction of dicyclopentadiene and norbornene to form tetracyclododecene are competing reactions. The reaction effect can be controlled by adjusting the ratio of norbornene and dicyclopentadiene in the raw materials. Increasing the amount of norbornene has an inhibitory effect on the polymerization reaction of norbornene and dicyclopentadiene. The molar ratio of norbornene (norbornene in norbornene vapor + norbornene in dicyclopentadiene solution) to dicyclopentadiene is generally controlled at 5-9:1, and can be further controlled at 6-7:1.

[0016] In the above production method, the mixture of norbornene and dicyclopentadiene in a suitable ratio becomes liquid at room temperature, reducing the use of inert solvents, increasing the concentration, and improving the reaction rate. The mass concentration of the norbornene solution in the dicyclopentadiene is 30%-50%, and can be further controlled to 35%-40%.

[0017] In the above production method, the reaction pressure of the spray reactor is 0.5-1.9 MPa, and can be further controlled to be 1.0-1.4 MPa.

[0018] In the above production method, the reaction temperature of the spray reactor is 230-270℃, and can be further controlled to 250-260℃.

[0019] In the above production method, the reaction time (reaction residence time) of the spray reactor is 2-9 min, and can be further controlled to 4-7 min.

[0020] In the above production method, the atomized particle size of the spray reactor is 0.1-0.5 mm, and can be further controlled to be 0.3-0.4 mm.

[0021] In the above production method, the spray outlet velocity of the spray reactor is 20-40 m / s, and can be further controlled to 25-35 m / s.

[0022] This invention does not impose any special limitations on the structure of the spray reactor, as long as the above-mentioned spray process parameters and effects can be achieved.

[0023] In the above production method, the buffer depressurization process mainly involves depressurizing the reaction products to match the pressure of the distillation process. Furthermore, the buffer depressurization can also cool the reaction products. The buffer temperature for the buffer depressurization is 120-180℃, and can be further controlled at 150-170℃. The buffer pressure for the buffer depressurization is 100-500 kPa, and can be further controlled at 300-400 kPa.

[0024] In the above production method, the distillation pressure is -100 kPa to -300 kPa, and can be further controlled to -200 kPa to -250 kPa.

[0025] In the above production method, the distillation temperature is 150-190℃, and can be further controlled to 160-170℃.

[0026] According to a specific embodiment of the present invention, the production method further includes recovering norbornene obtained by distillation, conveying it under heat to a gasification device for gasification, and then sending it into a spray reactor.

[0027] In the above production method, the heat preservation temperature is 50-60℃, and can be further controlled to 55-57℃.

[0028] The tetracyclododecene production method provided by this invention has a high dicyclopentadiene conversion rate and tetracyclododecene selectivity. In some specific embodiments, the dicyclopentadiene conversion rate of the above production method can reach over 98%, and can reach over 99%; the selectivity of norbornene can reach over 97%, and can further reach over 99%.

[0029] The present invention also provides a production system for tetracyclododecene, the system comprising: DCPD and NB solution tanks, a gasification device, a spray reactor, a buffer tank, and a distillation column;

[0030] The outlets of the DCPD and NB solution tanks and the gasification unit tank are connected to the inlet of the spray reactor. The spray reactor is connected to the inlet of the buffer tank, and the outlet of the buffer tank is connected to the inlet of the distillation column.

[0031] The above-mentioned tetracyclic dodecene production system can realize the above-mentioned tetracyclic dodecene production method provided by the present invention.

[0032] In the above system, the top outlet of the distillation column can also be connected to the inlet of the gasification device to gasify the norbornene obtained from distillation and reuse it in the spray reaction.

[0033] The beneficial effects of this invention include:

[0034] 1. The production method provided by the present invention involves dissolving dicyclopentadiene (DCPD) in norbornene (NB) to form a solution and then carrying out a spray reaction in an NB atmosphere in a spray reactor. This method can increase the concentration of NB in ​​the system without using an inert solvent, resulting in a short residence time, low reaction temperature, and significantly improved rate of DCPD conversion to tetracyclododecene (TCD). It also improves the conversion rate of DCPD and the selectivity of conversion to TCD. The reaction pressure is low and the residence time can be greatly shortened, resulting in low equipment requirements and high safety.

[0035] 2. The production method provided by this invention uses a spray reactor to diffuse DCPD solution droplets into an NB atmosphere, increasing the reaction area, accelerating the reaction rate, reducing residence time, and improving TCD production efficiency. The fast reaction speed and low temperature suppress side reactions and reduce the generation of byproducts.

[0036] 3. The production method provided by the present invention obtains raw material liquid by mixing a certain proportion of NB and DCPD at room temperature, thereby reducing the use of inert solvents, increasing the concentration, and improving the reaction rate. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the tetracyclododecene production system according to an embodiment of the present invention.

[0038] Symbol explanation: 1. DCPD and NB solution tanks; 2. Gasification unit; 3. Spray reactor; 4. Buffer tank; 5. Distillation column. Detailed Implementation

[0039] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0040] Embodiments of the present invention provide a production system for tetracyclododecene, such as Figure 1 As shown, the system includes DCPD and NB solution tanks 1, a gasification device 2, a spray reactor 3, a buffer tank 4, and a distillation column 5.

[0041] DCPD and NB solution tank 1 is used to contain DCPD and NB solution, and is equipped with an inlet and an outlet.

[0042] The gasification device 2 is used to gasify norbornene and has an inlet and an outlet.

[0043] The spray reactor 3 is used for spraying reactions. In this embodiment, the spray reactor 3 has an inlet at the top and an outlet at the bottom.

[0044] Buffer tank 4 is used for buffering and depressurization, and is equipped with an inlet and an outlet.

[0045] Distillation column 5 is used for the distillation of materials. Distillation column 5 has an inlet in the middle, and outlets at the top, bottom and side streams.

[0046] The outlets of DCPD and NB solution tank 1 and the vaporization unit 2 are connected to the inlet of spray reactor 3, respectively. The outlet of spray reactor 3 is connected to the inlet of buffer tank 4, and the outlet of buffer tank 4 is connected to the inlet of distillation column 5. Furthermore, the outlet at the top of distillation column 5 is connected to the inlet of vaporization unit 2 (not shown in the figure).

[0047] This invention also provides a method for producing tetracyclododecene, which is carried out in the above-mentioned system and specifically includes:

[0048] 1. The dicyclopentadiene norbornene solution in DCPD and NB solution tank 1 is heated in the pipeline and continuously pumped into spray reactor 3. At the same time, norbornene vapor in gasification device 2 is heated in the pipeline and introduced into spray reactor 3. The two materials are heated and pressurized in spray reactor 3 to the temperature and pressure required for the reaction.

[0049] The dicyclopentadiene norbornene solution and norbornene vapor are sprayed and reacted in spray reactor 3 to obtain reaction products; the main components of the reaction products are polymers of tetracyclododecene, norbornene, and cyclopentadiene.

[0050] In the above reaction, the molar ratio of norbornene (norbornene in norbornene vapor + norbornene in dicyclopentadiene solution) to dicyclopentadiene is 5-9:1, the reaction pressure of spray reactor 3 is 0.5-1.9 MPa, the reaction temperature is 230-270℃, the reaction time is 2-9 min, the atomized particle size is 0.1-0.5 mm, and the spray outlet flow rate is 20-40 m / s.

[0051] 2. The reaction product is continuously discharged from the bottom of the spray reactor 3 and then enters the buffer tank 4. It is buffered and depressurized under the conditions of 120-180℃ and 100-500kPa to obtain the reaction product liquid after cooling and pressurization.

[0052] 3. The reaction product liquid is continuously fed into distillation column 5 and distilled under conditions of -100kPa to -300kPa and 150-190℃ to obtain norbornene, tetracyclododecene, and heavy component by-products.

[0053] The heavy component by-products are collected from the bottom of the tower. The main components of the heavy component by-products are polymers of norbornene and cyclopentadiene.

[0054] Norbornene was extracted from the top of the column, while tetracyclic dodecene was extracted from the side stream.

[0055] 4. Recover norbornene and transport it back to gasification unit 2 at a temperature maintained at 50-60℃.

[0056] Examples 1 to 6

[0057] Examples 1 to 6 produced tetracyclododecene according to the above production method. Comparative Examples 1 to 6 used a batch reactor instead of a spray reactor, and the other conditions were the same.

[0058] Specifically, Comparative Example 1 and Example 1 form a control group, Comparative Example 2 and Example 2 form a control group, and so on. Comparative Example 6 and Example 6 form a control group. The only difference between the comparative examples and examples in the same control group is that the comparative examples do not use the parameters of the atomization reaction. Otherwise, the other conditions of the comparative examples and examples in the same control group, including the raw material composition (including the ratio of norbornene to DCPD and the concentration of DCPD solution), reaction pressure, reaction temperature, residence time, and the operating parameters of the buffer tank and distillation column, are the same.

[0059] The production parameters used in each embodiment and comparative example are shown in Table 1, the operating conditions are shown in Table 2, and the experimental results are shown in Table 3.

[0060] Table 1 Relevant parameter settings

[0061]

[0062] Table 2 Operating Conditions

[0063]

[0064] In this embodiment of the invention, the conversion rate of the dicyclopentadiene is defined as:

[0065] The selectivity of TCD is defined as:

[0066]

[0067] Table 3 Calculation results of data from Examples 1-6

[0068]

[0069]

[0070] As can be seen from Table 3, the production method provided by the present invention, by adopting a spray reaction and controlling the excess of norbornene relative to dicyclopentadiene, results in a high conversion rate of dicyclopentadiene after the reaction, and the conversion rate of dicyclopentadiene is better than that in the comparative example. This is because the gas-liquid mass transfer effect of the spray reactor is better than that of the batch reactor. The present invention can improve the gas-liquid mass transfer effect and thus improve the conversion rate of dicyclopentadiene by adopting a spray reaction.

[0071] Furthermore, the tetracyclododecene obtained by the spray reactor exhibits high selectivity (over 97%) and forms fewer polymers, while the comparative tetracyclododecene shows low selectivity and forms more polymers and high-boiling-point products. This is because after the tetracyclododecene product is generated in the spray reactor, the product and the feedstock dicyclopentadiene / cyclopentadiene no longer come into contact, whereas in the batch reactor, the tetracyclododecene remains in the reaction system after formation, increasing the probability of further reaction and polymer formation. These results demonstrate that using a spray reaction method can effectively reduce byproduct formation and improve the selectivity of tetracyclododecene.

[0072] The results above demonstrate that the production method provided by this invention, by dissolving dicyclopentadiene (DCPD) in norbornene (NB) to form a solution and conducting a spray reaction in an NB atmosphere within a spray reactor, increases the concentration of NB in ​​the system without using an inert solvent. This significantly increases the rate of DCPD conversion to tetracyclododecene (TCD), improves the conversion rate of DCPD and the selectivity for conversion to TCD, and allows for a lower reaction pressure while significantly shortening the residence time. This production method is a continuous reaction, enabling sustainable feed production.

Claims

1. A method for producing tetracyclododecene, the method comprising: A solution of dicyclopentadiene and norbornene and vaporized norbornene are fed into a spray reactor to react and obtain the reaction products. The molar ratio of norbornene to dicyclopentadiene is 5-9:1; The reaction product was buffered and depressurized to obtain a liquid reaction product. The reaction product liquid was distilled to obtain norbornene and tetracyclododecene, respectively.

2. The production method according to claim 1, wherein, The mass concentration of the dicyclopentadiene norbornene solution is 30%-50%.

3. The production method according to claim 1, wherein, The reaction pressure of the spray reactor is 0.5-1.9 MPa; The reaction temperature of the spray reactor is 230-270℃; The reaction time of the spray reactor is 2-9 minutes.

4. The production method according to claim 1, wherein, The atomized particles of the spray reactor have a particle size of 0.1-0.5 mm.

5. The production method according to claim 1, wherein, The spray outlet velocity of the spray reactor is 20-40 m / s.

6. The production method according to claim 1, wherein, The buffer temperature for the buffer pressure reduction is 120-180℃, and the buffer pressure for the buffer pressure reduction is 100-500kPa.

7. The production method according to claim 1, wherein, The distillation pressure is -100 kPa to -300 kPa, and the distillation temperature is 150-190 °C.

8. The production method according to claim 1, wherein, The production method further includes recovering norbornene obtained from distillation, keeping it warm and transporting it to a gasification device for gasification, and then sending the gasified norbornene into a spray reactor.

9. The production method according to claim 8, wherein, The insulation temperature is 50-60℃.

10. A system for producing tetracyclododecene, the system comprising: DCPD and NB solution tanks, gasification units, spray reactors, buffer tanks, and distillation columns; The outlets of the DCPD and NB solution tanks and the gasification unit tank are connected to the inlet of the spray reactor. The spray reactor is connected to the inlet of the buffer tank, and the outlet of the buffer tank is connected to the inlet of the distillation column.

11. The system according to claim 10, wherein, The top outlet of the distillation column is connected to the inlet of the gasification device.

12. The system according to claim 10, wherein, The tetracyclododecene production system is capable of realizing the tetracyclododecene production method according to any one of claims 1-9.

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