A process for the production of norbornene and tetracyclododecene

Abstract

The application discloses a production method of norbornene and tetradecalin. The method comprises the following steps: after ethylene is reacted with dicyclopentadiene and / or cyclopentadiene under certain temperature and pressure, gas-liquid separation is carried out, and after gradient rectification of a liquid product mixture, norbornene product and tetradecalin product are obtained; and after purification of excessive ethylene, unreacted dicyclopentadiene and / or cyclopentadiene and a solvent, the solvent is recycled. In particular, the application can achieve the purpose of maximum production of tetradecalin by recycling norbornene solution which is not rectified and purified to the reaction device to continue the Diels-Alder reaction with cyclopentadiene; meanwhile, the purpose of maximum production of norbornene can be achieved by cracking tetradecalin solution to generate norbornene and cyclopentadiene. Therefore, the application can flexibly adjust the production ratio of the two products according to production requirements, reduces the investment cost and has good economic benefits.

Description

Technical Field

[0001] This invention relates to a method for producing norbornene and tetracyclododecene. Background Technology

[0002] Norbornene (NB) and tetracyclododecene (TCD) products are widely used in the synthesis of cyclic olefin copolymers / polymers (COC / COP). Cyclic olefin polymers have advantages such as low density, low moisture absorption, high transparency, high heat resistance, high refractive index, and excellent processability. They are amorphous thermoplastic polymer materials that have attracted great attention in industry and academia in recent years. Since Joshel et al. first reported the synthesis reaction of norbornene (NB) in 1941, there have been continuous patents and literature reports on the development and research of synthesis processes for norbornene and tetracyclododecene.

[0003] The industrial production processes suitable for norbornene and its derivatives can be divided into two types: liquid-phase reaction processes and gas-phase reaction processes. In the liquid-phase reaction process, cyclopentadiene (CPD) or dicyclopentadiene (DCPD) is in a liquid state during the reaction, and ethylene gas dissolves into the liquid phase to undergo an addition reaction. In the gas-phase reaction process, cyclopentadiene (CPD) or dicyclopentadiene (DCPD) is first heated to vaporize, mixed with ethylene gas, and then introduced into the reaction apparatus for reaction. During the reaction, the generated norbornene (NB) readily reacts with cyclopentadiene (CPD) to generate tetracyclododecene (TCD), and tetracyclododecene can also be used for the synthesis of cyclic olefin copolymers (COC).

[0004] Chinese patent CN104692993A discloses a method for synthesizing norbornene using a microchannel reactor, employing precision machining technology to manufacture microreactors with characteristic dimensions ranging from 10 to 300 micrometers. Experiments show that this method has high heat transfer efficiency, rapidly transferring reaction heat into and out of the system, avoiding the generation of reaction hotspots and effectively suppressing side reactions; it also boasts high mass transfer efficiency and is relatively safe, with high raw material conversion rate and norbornene selectivity. However, the microchannel method is difficult to apply to industrial-scale mass production of norbornene. Chinese patent CN102249839A discloses a method for synthesizing norbornene using a loop reactor. This method has advantages in pressure resistance and rapid heat transfer, high safety, and can achieve a high conversion rate of cyclopentadiene. However, it tends to produce a large amount of tetracyclododecene, making it impossible to control the production ratio of both.

[0005] 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 method simply produces and distills two products, failing to address the issue of controlling the ratio of tetracyclododecene and norbornene.

[0006] Japanese patent application JP5344808B2 discloses a method for suppressing the production of cyclic olefins such as TCD and NB by inhibiting the production of heavy byproducts. The method reduces the generation of heavy byproducts by storing DCPD under low temperature and low oxygen concentration conditions. The reaction apparatus can be used to prepare norbornene by adding ethylene and DCPD and / or CPD, or to prepare TCD by adding NB and CPD, offering a degree of flexibility. However, it cannot simultaneously and continuously produce two cyclic olefins in the same process.

[0007] Chinese patent application CN115433053A discloses a method for the co-production of TCD and NB. The method involves reacting a DCPD solution with ethylene in a tubular reactor to obtain a co-product of TCD and NB. This method eliminates the need for NB preparation, directly reacting DCPD 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 only allows adjustment of the NB and TCD production ratio by adjusting reaction conditions; it cannot affect the output ratio without affecting the reactor conditions. Furthermore, if a ratio error occurs during production, it cannot continuously monitor and adjust the production ratio.

[0008] Japanese Patent JP4526142B2 describes a process for preparing norbornene using dicyclopentadiene and ethylene. The resulting norbornene is separated, with a portion recycled and the remainder produced as a product. During this process, the light fractions of norbornene and cyclopentadiene are further distilled to recover cyclopentadiene and a portion of norbornene, significantly improving the conversion rate of dicyclopentadiene.

[0009] Chinese patent CN115385769A discloses a method for reducing byproducts in the synthesis of tetracyclododecene from dicyclopentadiene. The method involves continuously adding a small amount of dicyclopentadiene solution dropwise to a large amount of norbornene solution. The added dicyclopentadiene is immediately consumed, maintaining a high molar ratio of norbornene to dicyclopentadiene and reducing the formation of polycyclopentadiene during the reaction. The system is operated under an ethylene atmosphere to suppress the decomposition of norbornene. This method can produce tetracyclododecene with high purity, and the process is simple and highly operable. However, this method requires norbornene as a raw material, and reducing the concentration of dicyclopentadiene makes it inconvenient to simultaneously prepare norbornene and tetracyclododecene.

[0010] Chinese patent CN105481625A uses two series-connected batch reactors. The first reactor has a lower temperature and shorter residence time, while the second reactor has a higher temperature and longer residence time. During the reaction, heat balance is achieved through the endothermic depolymerization of dicyclopentadiene and the exothermic reaction of the diene. High ethylene concentration and low cyclopentadiene concentration inhibit the reaction from transitioning to a polymer, while total backmixing addresses mass transfer and heat conversion. However, it does not address how to handle the generated heavy byproducts, resulting in a lower-than-expected norbornene production rate.

[0011] Chinese patent CN103664470A combines the mass transfer advantages of a batch reactor with the process stability and operational safety advantages of a tubular reactor under high-pressure conditions, achieving a norbornene yield of 90-98% in its preparation method. However, while this method optimizes reaction conditions and reduces byproduct generation, it does not further treat the obtained byproducts, resulting in less effective results than the inventors anticipated. Furthermore, compared to a batch reactor, the tubular reactor process for norbornene production results in a greater accumulation of polymers on the reactor walls, thus affecting the economic efficiency and safety of the reactor. Summary of the Invention

[0012] To at least partially address the aforementioned technical problems in the prior art, the present invention aims to provide a production method that allows for flexible adjustment of the ratio of norbornene and tetracyclododecene during the production process. The production method of the present invention utilizes a batch reactor, enabling long-term stable operation of the equipment. Furthermore, this method can further improve the conversion rate of dicyclopentadiene and the selectivity of norbornene and tetracyclododecene.

[0013] As one aspect of the present invention, a method for producing norbornene and tetracyclododecene is provided, the method comprising the following steps:

[0014] S1. An organic solution of mixed ethylene and dicyclopentadiene and / or cyclopentadiene is reacted in a reaction apparatus to obtain a gas-liquid mixture product.

[0015] S2. The gas-liquid mixture obtained in S1 is subjected to flash evaporation separation to recover the gaseous product and obtain the liquid product.

[0016] S3. In the first distillation column, the liquid product obtained in S2 is separated by distillation to obtain a light distillate and a bottom product.

[0017] S4. The light distillate obtained in S3 is diverted to the second distillation column and / or reaction unit in a certain proportion;

[0018] S5. In the second distillation column, the light fraction product separated from S4 is distilled again and separated, and cyclopentadiene is recovered to obtain norbornene product; at the same time, in the third distillation column, the bottom product is distilled again and separated, and cyclopentadiene is recovered to obtain solvent and heavy fraction product.

[0019] S6. The heavy component products obtained in S5 are diverted to the cracking tower and / or the fourth distillation tower in proportion;

[0020] S7. In the cracking tower, a solvent is added to the heavy fraction product that was separated in S6, and the product is distilled and separated to obtain a light fraction product, which is treated in the same way as in S4; a solvent is added to the fourth distillation tower, and the product is distilled and separated to obtain a tetracyclododecene product.

[0021] In S3, the bottom product includes solvent, cyclopentadiene, tetracyclododecene, and polycyclopentadiene.

[0022] In any specific embodiment, in S4, the split ratio of the light distillate product is arbitrarily adjusted from 0% to 100%; or adjusted according to a pre-set production ratio of the norbornene product and the tetracyclododecene product. In this embodiment of the invention, when the split ratio of the light distillate product in the distillation column is 0%, the second distillation column is not started and is not heated.

[0023] In any specific embodiment, in S6, the split ratio of the heavy component product is arbitrarily adjusted from 0% to 100%; or adjusted according to a pre-set production ratio of the norbornene product and the tetracyclododecene product. In this embodiment of the invention, when the split ratio of the heavy component product in the distillation column is 0%, the fourth distillation column is not started and is not heated; when the split ratio of the heavy component product in the distillation column is 100%, the cracking column is not started and is not heated.

[0024] In any specific embodiment, in S1, the solvent of the organic solution is selected from one or more of cycloalkanes, alkanes, and aromatic organic solvents.

[0025] As a preferred embodiment of the present invention, the organic solvent is selected from one or more of cyclohexane, methylcyclohexane, decane, n-dodecane, and toluene.

[0026] In any specific embodiment, in S1, the molar ratio of ethylene to dicyclopentadiene and / or cyclopentadiene (dicyclopentadiene is calculated as cyclopentadiene) is 20:1 to 40:1, and the mass fraction of dicyclopentadiene and / or cyclopentadiene in the organic solution is 20 to 60%.

[0027] As a preferred embodiment of the present invention, the molar ratio of ethylene to dicyclopentadiene and / or cyclopentadiene (dicyclopentadiene is calculated as cyclopentadiene, i.e., 1 mole of dicyclopentadiene is calculated as 2 moles of cyclopentadiene) is 25:1 to 35:1, and the mass fraction of dicyclopentadiene and / or cyclopentadiene in the organic solution is 30 to 50%.

[0028] In any specific embodiment, in S1, when both dicyclopentadiene and cyclopentadiene are used as raw materials, the mass fraction of cyclopentadiene is 2 to 10 wt%.

[0029] In any specific embodiment, in step S1, the reaction temperature is 100–400°C, the reaction pressure is 1–50 MPa, and the reaction residence time is 0.1–10 h.

[0030] As a preferred embodiment of the present invention, in step S1, the reaction temperature is 170–320°C, the reaction pressure is 2–20 MPa, and the reaction residence time is 0.2–5 h.

[0031] In any specific embodiment, in step S2, the separation temperature is 20–160°C and the separation pressure is 100–1000 kPa.

[0032] As a preferred embodiment of the present invention, in step S2, the separation temperature is 40–100°C and the separation pressure is 300–700 kPa.

[0033] In any specific embodiment, the bottom temperature of the first distillation column is 60–130°C, and the distillation pressure is 10–20 kPa;

[0034] And / or, the reboiler temperature of the second distillation column is 40–150°C, and the distillation pressure is 1–40 kPa;

[0035] And / or, the reboiler temperature of the third distillation column is 70–180°C, and the distillation pressure is 30–100 kPa;

[0036] And / or, the bottom temperature of the fourth distillation column is 100-200°C, and the distillation pressure is 30-100 kPa.

[0037] In any specific embodiment, during step S4, when the light distillate product is split, the splitting temperature is set to 50–90°C.

[0038] In any specific embodiment, during S6, when the recombinant product is split, the splitting temperature is set to 150-180°C.

[0039] In any specific embodiment, in S7, the solvent is a solvent with a boiling point higher than 250°C; the solvent with a boiling point higher than 250°C is preferably one or more of benzophenone, diphenyl ether, and benzamide.

[0040] In any specific embodiment, in S7, the volume ratio of the solvent to the recombinant component product is 1:(3-10).

[0041] In any specific embodiment, in S7, the temperature of the bottom of the cracking tower is 120-270°C, and the pressure of the cracking distillation is 1200-1400 kPa.

[0042] The production method employed in this invention precisely controls the production ratio of norbornene by recovering a portion of it and by cracking and distilling a portion of tetracyclododecene.

[0043] Since different grades of cyclic olefin polymers require different proportions of components in the cyclic olefin raw materials, this invention can flexibly produce cyclic olefin polymer raw materials with different composition ratios by adjusting the production ratio of norbornene and tetracyclododecene, so as to produce different grades of cyclic olefin polymers.

[0044] This invention reduces the amount of waste that needs to be treated and saves costs by cracking and distilling heavy products, thus achieving good economic benefits.

[0045] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained in accordance with the structures particularly pointed out in the description, claims and drawings. Attached Figure Description

[0046] Figure 1 This is a process flow diagram of the production system of the present invention;

[0047] Figure 2 A conventional production process flow diagram omitting the diversion device;

[0048] In the diagram: 1. Ethylene tank; 2. DCPD / CPD tank; 3. Reaction apparatus; 4. Flash tank; 5. First distillation column; 6. Second distillation column; 7. Third distillation column; 8. Fourth distillation column; 9. Inert solvent storage tank; 10. Light fraction product splitter; 11. Heavy fraction product splitter; 12. Cracking column. Detailed Implementation

[0049] The present invention will be further described below with reference to specific embodiments. The scope of protection of the present invention is not limited by the following embodiments.

[0050] The materials involved in the following examples are all conventional commercially available products.

[0051] The inventors used the technical solution of this invention to produce norbornene and tetracyclododecene, and made Examples 1 to 12.

[0052] Example 1

[0053] In this embodiment, the molar ratio of ethylene to dicyclopentadiene is 20:1, the mass fraction of dicyclopentadiene in the organic solvent is 50%, and the mass fraction of cyclopentadiene in both cyclopentadiene and dicyclopentadiene is 2%.

[0054] The norbornene and tetracyclododecene in this embodiment are prepared by the following steps:

[0055] (1) Dicyclopentadiene, organic solvent (cyclohexane: toluene = 1:1) and ethylene were added in sequence according to the ratio. Under stirring conditions, the temperature was increased to 280℃ and the pressure was increased to 3MPa. The reaction was held for 4 hours to obtain a gas-liquid mixture.

[0056] (2) The pressure in flash tank 4 is controlled at 300 kPa and the temperature at 40°C to separate the gas-liquid mixture and recover the washed ethylene gas to obtain the liquid product. The pressure in the first distillation column 5 is controlled at 13 kPa and the temperature at 80°C to perform a first distillation of the liquid product to obtain light and heavy fractions. The light fraction enters the light fraction splitter 10, and the split ratio in the first distillation column 5 is controlled at 80%, i.e., 80% enters the second distillation column 6 and 20% enters the reaction device 3. The pressure in the second distillation column 6 is controlled at 10 kPa and the temperature at 80°C to perform a second distillation of the light fraction to obtain norbornene. The pressure in the third distillation column 7 is controlled at 50 kPa and the temperature at 110°C to perform a second distillation of the heavy fraction to obtain the solvent and the heavy components. The heavy component product enters the heavy component product splitter 11, and the split ratio of the fourth distillation column 8 is controlled to be 100%, that is, 100% enters the fourth distillation column 8 and 0% enters the cracking column 12; the volume ratio of the high-boiling solvent (benzophenone: diphenyl ether = 1:1) to the heavy component is controlled to be 1:7, and the pressure inside the fourth distillation column 8 is controlled to be 50 kPa and the temperature to be 130 °C. The heavy component is distilled to obtain tetracyclododecene and polycyclopentadiene.

[0057] (3) The cracking tower 12 is not turned on and is not heated.

[0058] Implementation principle: Refer to the appendix Figure 1 The prepared dicyclopentadiene and organic solvent are pumped into the reaction device 3 from the DCPD / CPD tank 2. The liquid level is monitored in real time by the liquid level gauge. When the liquid level in the reaction device 3 exceeds a certain height, the reaction device 3 starts to automatically heat and stir. The ethylene tank 1 is opened and the required ethylene is continuously introduced. The temperature is raised to 280°C and left in the reaction device 2 for 4 hours to obtain a gas-liquid mixture.

[0059] The gas-liquid mixture includes: ethylene, cyclopentadiene, dicyclopentadiene, norbornene, tetracyclododecene, polycyclopentadiene, and organic solvents.

[0060] When the liquid level in reaction device 3 is higher than 70%, the outlet of reaction device 3 is opened under motor adjustment to control the liquid level at 70%. The reaction liquid in reaction device 3 flows continuously out of the outlet into flash tank 4. In flash tank 4, the reaction mixture fed through the inlet undergoes gas-liquid separation. The separated unreacted ethylene comes into contact with the reaction solvent sprayed in the scrubbing device at the top of the tower. The solvent absorbs the unreacted cyclopentadiene and norbornene in the gas and mixes with the reaction liquid, completing the gas-liquid separation.

[0061] The top outlet of the flash tank 4 is the gaseous product ethylene, which is recycled back to the reaction device 3 for reuse. The bottom outlet of the flash tank 4 is the liquid product, including cyclopentadiene, dicyclopentadiene, norbornene, tetracyclododecene, polycyclopentadiene, and organic solvents.

[0062] After gas-liquid separation, the bottom outlet of flash tank 4 is opened to allow the liquid product to continuously enter the first distillation column 5, where light fraction containing norbornene, solvent, and cyclopentadiene and heavy fraction by-products are separated by distillation.

[0063] The first distillation column produces light distillate products at the top, including dicyclopentadiene, cyclopentadiene, and norbornene; the first distillation column produces heavy by-products at the bottom.

[0064] The light distillate is split proportionally, and the flow rate of the light distillate is detected using a flow meter. The opening and closing of the product valve and reflux valve are adjusted by the light distillate product splitter 10 to recover and recycle the light distillate into the reaction unit 3 or into the second distillation column 6. 20% of the recovered product is sent to the reaction unit 3, and the other 80% is continuously sent to the second distillation column 6. If there is any light distillate entering the second distillation column, it is stirred and heated to separate norbornene product by distillation. Cyclopentadiene is recovered and sent to the DCPD / CPD tank 2 for recycling. At the same time, the remaining solvent is discharged.

[0065] In this process, non-condensable ethylene is collected from the top of the second distillation column, cyclopentadiene is collected from the side stream for recycling, and norbornene is collected from the bottom of the column.

[0066] Heavy byproducts are continuously pumped from the first distillation column 5 into the third distillation column 7, stirred and heated, and the solvent is separated by distillation. Cyclopentadiene is recovered and enters the DCPD / CPD tank 2. Heavy components are collected from the bottom of the column, and the flow rate of heavy components is detected by a flow meter. The opening and closing of the product valve and reflux valve are adjusted by the heavy component product distributor 11 so that the heavy components enter the fourth distillation column 8 or the cracking column 12 in proportion. 100% of them enter the fourth distillation column 8. If there are heavy components entering the fourth distillation column 8, the high-boiling-point solvent is pumped from the inert solvent storage tank 9 into the fourth distillation column 8 to prevent the accumulation of polymers in the column bottom from clogging the pipeline, which would be detrimental to continuous production and even cause danger. Stirring and heating are used to separate tetracyclododecene by distillation, and polycyclopentadiene is collected from the bottom of the column. In the third distillation column, the solvent is collected from the top, cyclopentadiene is collected from the side stream for recycling, and heavy components, including tetracyclododecene and polycyclopentadiene, are collected from the bottom. The heavy components enter the fourth distillation column. The tetracyclododecene product is collected from the top of the fourth distillation column, and polycyclopentadiene is collected from the bottom.

[0067] If any heavy components enter cracking column 12, they are pumped in from inert solvent storage tank 9 with a high-boiling-point solvent for mixing, stirring, and heating. The cracking distillation yields crude norbornene, which is then mixed with the light component product from the first distillation column. Norbornene and cyclopentadiene are collected from the top of the cracking column, while polycyclopentadiene is collected from the bottom.

[0068] Example 2

[0069] In this embodiment, the molar ratio of ethylene to dicyclopentadiene is 30:1, the mass fraction of dicyclopentadiene in the organic solution is 44%, and the mass fraction of cyclopentadiene in the total mass fraction of cyclopentadiene and dicyclopentadiene is 3%.

[0070] The norbornene and tetracyclododecene in this embodiment are prepared by the following steps:

[0071] (1) Dicyclopentadiene, organic solvent (methylcyclohexane: toluene = 1:1) and ethylene were added in sequence according to the ratio. Under stirring conditions, the temperature was increased to 200℃ and the pressure was increased to 9MPa. The reaction was held for 0.3h to obtain a gas-liquid mixture.

[0072] (2) The pressure in flash tank 4 is controlled at 600 kPa and the temperature at 80°C to separate the gas-liquid mixture and recover the washed ethylene gas to obtain the liquid product. The pressure in the first distillation column 5 is controlled at 16 kPa and the temperature at 90°C to distill the liquid product once to obtain the light fraction and the heavy fraction by-product. The light fraction enters the light fraction product splitter 10, and the split ratio of the first distillation column 5 is controlled at 70%, that is, 70% enters the second distillation column 6 and 30% enters the reaction device 3. The pressure in the second distillation column 6 is controlled at 13 kPa and the temperature at 100°C to distill the fraction twice to obtain norbornene. The pressure in the third distillation column 7 is controlled at 55 kPa and the temperature at 120°C to distill the heavy fraction twice to obtain the solvent and the heavy fraction. The heavy fraction enters the heavy fraction product splitter 11, and the split ratio of the fourth distillation column 8 is controlled at 100%, that is, 100% enters the fourth distillation column 8 and 0% enters the cracking column 12. The volume ratio of the high-boiling-point solvent (benzophenone:benzamide = 1:1) to the heavy component was controlled at 1:3. The pressure inside the fourth distillation column 8 was controlled at 55 kPa and the temperature at 140 °C. The heavy component was distilled to obtain tetracyclododecene and polycyclopentadiene.

[0073] (3) The cracking tower 12 is not turned on and is not heated.

[0074] Example 3

[0075] In this embodiment, the molar ratio of ethylene to dicyclopentadiene is 40:1, the mass fraction of dicyclopentadiene in the organic solution is 40%, and the mass fraction of cyclopentadiene in the total mass fraction of cyclopentadiene and dicyclopentadiene is 4%.

[0076] Norbornene in this embodiment is prepared through the following steps:

[0077] (1) Dicyclopentadiene, organic solvent (decane: toluene = 1:1) and ethylene were added in sequence according to the ratio. Under stirring conditions, the temperature was increased to 240℃ and the pressure was increased to 15MPa. The reaction was held for 2 hours to obtain a gas-liquid mixture.

[0078] (2) The pressure in flash tank 4 is controlled at 400 kPa and the temperature at 50 °C. The gas-liquid mixture is separated, and the washed ethylene gas is recovered to obtain the liquid product. The pressure in the first distillation column 5 is controlled at 14 kPa and the temperature at 100 °C. The liquid product is distilled once to obtain light fraction and heavy fraction by-product. The light fraction enters the light fraction product splitter 10. The split ratio of the first distillation column 5 is controlled at 100%, that is, 100% enters the second distillation column 6 and 0% enters the reaction device 3. The pressure in the second distillation column 6 is controlled at 12 kPa and the temperature at 90 °C. The distillation product is distilled twice to obtain norbornene. The pressure in the third distillation column 7 is controlled at 60 kPa and the temperature at 130 °C. The heavy fraction product is distilled twice to obtain the solvent and heavy fraction. The heavy fraction product enters the heavy fraction product splitter 11. The split ratio of the fourth distillation column 8 is controlled at 0%, that is, 0% enters the fourth distillation column 8 and 100% enters the cracking column 12. The volume ratio of the high-boiling-point solvent (diphenyl ether: benzamide = 1:1) to the heavy component is controlled at 1:10; the fourth distillation column 8 is not turned on and is not heated;

[0079] (3) The pressure inside the cracking tower 12 is controlled at 1350 kPa and the temperature at 240 °C. The heavy components are cracked to obtain norbornene and cyclopentadiene. Norbornene and cyclopentadiene enter the second distillation tower.

[0080] Example 4

[0081] In this embodiment, the molar ratio of ethylene to dicyclopentadiene is 25:1, the mass fraction of dicyclopentadiene in the organic solution is 45%, and the mass fraction of cyclopentadiene in the total mass fraction of cyclopentadiene and dicyclopentadiene is 10%.

[0082] Norbornene in this embodiment is prepared through the following steps:

[0083] (1) Add dicyclopentadiene, organic solvent (cyclohexane: methylcyclohexane = 1:1) and ethylene in sequence according to the ratio. Under stirring conditions, raise the temperature to 260°C and the pressure to 5MPa. Let the reaction stand for 3 hours to obtain a gas-liquid mixture.

[0084] (2) The pressure in flash tank 4 is controlled at 500 kPa and the temperature at 60°C to separate the gas-liquid mixture and recover the washed ethylene gas to obtain the liquid product. The pressure in the first distillation column 5 is controlled at 15 kPa and the temperature at 90°C to distill the liquid product once to obtain the light fraction and the heavy fraction by-product. The light fraction enters the light fraction product splitter 10, and the distillation column split ratio is controlled at 100%, that is, 100% enters the second distillation column 6 and 0% enters the reaction device 3. The pressure in the second distillation column 6 is controlled at 14 kPa and the temperature at 110°C to distill the fraction twice to obtain norbornene. The pressure in the third distillation column 7 is controlled at 70 kPa and the temperature at 135°C to distill the heavy fraction twice to obtain the solvent and the heavy fraction. The heavy fraction enters the heavy fraction product splitter 11, and the split ratio in the fourth distillation column 8 is controlled at 80%, that is, 80% enters the fourth distillation column 8 and 20% enters the cracking column 12. The volume ratio of the high-boiling-point solvent (benzophenone: diphenyl ether = 1:1) to the heavy component was controlled at 1:3. The pressure inside the fourth distillation column 8 was controlled at 70 kPa and the temperature at 155 °C. The heavy component was distilled to obtain tetracyclododecene and polycyclopentadiene.

[0085] (3) The pressure inside the cracking tower 12 is controlled at 1200 kPa and the temperature at 180 °C. The heavy components are cracked to obtain norbornene and cyclopentadiene. Norbornene and cyclopentadiene enter the second distillation tower.

[0086] Example 5

[0087] In this embodiment, the molar ratio of ethylene to dicyclopentadiene is 35:1, the mass fraction of dicyclopentadiene in the organic solution is 30%, and the mass fraction of cyclopentadiene in the total mass fraction of cyclopentadiene and dicyclopentadiene is 9%.

[0088] Norbornene in this embodiment is prepared through the following steps:

[0089] (1) Add dicyclopentadiene, organic solvent (cyclohexane: n-dodecane = 1:1) and ethylene in sequence according to the ratio. Under stirring conditions, raise the temperature to 280°C and the pressure to 6MPa. Let the reaction stand for 1 hour to obtain a gas-liquid mixture.

[0090] (2) The pressure in flash tank 4 is controlled at 650 kPa and the temperature at 70°C to separate the gas-liquid mixture and recover the washed ethylene gas to obtain the liquid product. The pressure in the first distillation column 5 is controlled at 18 kPa and the temperature at 100°C to distill the liquid product once to obtain the light distillate and the heavy distillate by-product. The light distillate enters the light distillate product splitter 10, and the distillation column split ratio is controlled at 0%, that is, 0% enters the second distillation column 6 and 100% enters the reaction device 3. The second distillation column 6 is not turned on and is not heated. The pressure in the third distillation column 7 is controlled at 75 kPa and the temperature at 140°C to distill the heavy distillate a second time to obtain the solvent and the heavy component. The heavy distillate enters the heavy distillate product splitter 11, and the split ratio in the fourth distillation column 8 is controlled at 100%, that is, 100% enters the fourth distillation column 8 and 0% enters the cracking column 12. The volume ratio of the high-boiling-point solvent (benzophenone: benzamide = 1:1) to the heavy component was controlled at 1:4. The pressure inside the fourth distillation column 8 was controlled at 75 kPa and the temperature at 160 °C. The heavy component was distilled to obtain tetracyclododecene and polycyclopentadiene.

[0091] (3) The cracking tower 12 is not turned on and is not heated.

[0092] Example 6

[0093] In this embodiment, the molar ratio of ethylene to dicyclopentadiene is 40:1, the mass fraction of dicyclopentadiene in the organic solution is 35%, and the mass fraction of cyclopentadiene in the total mass fraction of cyclopentadiene and dicyclopentadiene is 8%.

[0094] Norbornene in this embodiment is prepared through the following steps:

[0095] (1) Add dicyclopentadiene, organic solvent (cyclohexane: methylcyclohexane = 1:1) and ethylene in sequence according to the ratio. Under stirring conditions, raise the temperature to 220°C and the pressure to 10MPa. Let the reaction stand for 7 hours to obtain a gas-liquid mixture.

[0096] (2) The pressure in flash tank 4 is controlled at 700 kPa and the temperature at 100 °C to separate the gas-liquid mixture and recover the washed ethylene gas to obtain the liquid product. The pressure in the first distillation column 5 is controlled at 17 kPa and the temperature at 80 °C to distill the liquid product once to obtain the light fraction and the heavy fraction by-product. The light fraction enters the light fraction product splitter 10, and the distillation column split ratio is controlled at 100%, that is, 100% enters the second distillation column 6 and 0% enters the reaction device 3. The pressure in the second distillation column 6 is controlled at 16 kPa and the temperature at 100 °C to distill the fraction twice to obtain norbornene. The pressure in the third distillation column 7 is controlled at 80 kPa and the temperature at 150 °C to distill the heavy fraction twice to obtain the solvent and the heavy fraction. The heavy fraction enters the heavy fraction product splitter 11, and the split ratio in the fourth distillation column 8 is controlled at 50%, that is, 50% enters the fourth distillation column 8 and 50% enters the cracking column 12. The volume ratio of the high-boiling-point solvent (diphenyl ether: benzamide = 1:1) to the heavy component was controlled at 1:9. The pressure inside the fourth distillation column 8 was controlled at 80 kPa and the temperature at 170 °C. The heavy component was distilled to obtain tetracyclododecene and polycyclopentadiene.

[0097] (3) The pressure inside the cracking tower 12 is controlled at 1280 kPa and the temperature at 240 °C. The heavy components are cracked to obtain norbornene and cyclopentadiene. Norbornene and cyclopentadiene enter the second distillation tower.

[0098] Example 7

[0099] In this embodiment, the molar ratio of ethylene to dicyclopentadiene is 30:1, the mass fraction of dicyclopentadiene in the organic solution is 20%, and the mass fraction of cyclopentadiene in the total mass fraction of cyclopentadiene and dicyclopentadiene is 7%.

[0100] Norbornene in this embodiment is prepared through the following steps:

[0101] (1) Add dicyclopentadiene, organic solvent (methylcyclohexane: n-dodecane = 1:1) and ethylene in sequence according to the ratio. Under stirring conditions, raise the temperature to 100°C and the pressure to 45 MPa. Let the reaction stand for 10 hours to obtain a gas-liquid mixture.

[0102] (2) The pressure in flash tank 4 is controlled at 100 kPa and the temperature at 20°C to separate the gas-liquid mixture and recover the washed ethylene gas to obtain the liquid product. The pressure in the first distillation column 5 is controlled at 10 kPa and the temperature at 60°C to distill the liquid product once to obtain the light fraction and the heavy fraction by-product. The light fraction enters the light fraction product splitter 10, and the distillation column split ratio is controlled at 50%, that is, 50% enters the second distillation column 6 and 50% enters the reaction device 3. The pressure in the second distillation column 6 is controlled at 1 kPa and the temperature at 40°C to distill the fraction twice to obtain norbornene. The pressure in the third distillation column 7 is controlled at 30 kPa and the temperature at 70°C to distill the heavy fraction twice to obtain the solvent and the heavy fraction. The heavy fraction enters the heavy fraction product splitter 11, and the split ratio in the fourth distillation column 8 is controlled at 100%, that is, 100% enters the fourth distillation column 8 and 0% enters the cracking column 12. The volume ratio of the high-boiling-point solvent (benzophenone) to the heavy component was controlled at 1:8. The pressure in the fourth distillation column was controlled at 30 kPa and the temperature at 100 °C. The heavy component was distilled to obtain tetracyclododecene and polycyclopentadiene.

[0103] (3) The cracking tower 12 is not turned on and is not heated.

[0104] Example 8

[0105] In this embodiment, the molar ratio of ethylene to dicyclopentadiene is 30:1, the mass fraction of dicyclopentadiene in the organic solution is 25%, and the mass fraction of cyclopentadiene in the total mass fraction of cyclopentadiene and dicyclopentadiene is 6%.

[0106] Norbornene in this embodiment is prepared through the following steps:

[0107] (1) Add dicyclopentadiene, organic solvent (methylcyclohexane: decane = 1:1) and ethylene in sequence according to the ratio. Under stirring conditions, raise the temperature to 100°C and the pressure to 50 MPa. Let the reaction stand for 8 hours to obtain a gas-liquid mixture.

[0108] (2) The pressure in flash tank 4 is controlled at 200 kPa and the temperature at 30°C to separate the gas-liquid mixture and recover the washed ethylene gas to obtain the liquid product. The pressure in the first distillation column 5 is controlled at 11 kPa and the temperature at 70°C to distill the liquid product once to obtain the light fraction and the heavy fraction by-product. The light fraction enters the light fraction product splitter 10, and the distillation column split ratio is controlled at 100%, that is, 100% enters the second distillation column 6 and 0% enters the reaction device 3. The pressure in the second distillation column 6 is controlled at 20 kPa and the temperature at 140°C to distill the fraction twice to obtain norbornene. The pressure in the third distillation column 7 is controlled at 100 kPa and the temperature at 180°C to distill the heavy fraction twice to obtain the solvent and the heavy fraction. The heavy fraction enters the heavy fraction product splitter 11, and the split ratio in the fourth distillation column 8 is controlled at 100%, that is, 100% enters the fourth distillation column 8 and 0% enters the cracking column 12. The volume ratio of the high-boiling-point solvent (diphenyl ether) to the heavy component was controlled at 1:5. The pressure inside the fourth distillation column 8 was controlled at 100 kPa and the temperature at 200 °C. The heavy component was distilled to obtain tetracyclododecene and polycyclopentadiene.

[0109] (3) The cracking tower 12 is not turned on and is not heated.

[0110] Example 9

[0111] In this embodiment, the molar ratio of ethylene to dicyclopentadiene is 30:1, the mass fraction of dicyclopentadiene in the organic solution is 35%, and the mass fraction of cyclopentadiene in the total mass fraction of cyclopentadiene and dicyclopentadiene is 5%.

[0112] Norbornene in this embodiment is prepared through the following steps:

[0113] (1) Dicyclopentadiene, organic solvent (n-dodecane:toluene = 1:1) and ethylene were added in sequence according to the ratio. Under stirring conditions, the temperature was increased to 170°C and the pressure was increased to 35MPa. The reaction was held for 9 hours to obtain a gas-liquid mixture.

[0114] (2) The pressure in flash tank 4 is controlled at 700 kPa and the temperature at 110°C to separate the gas-liquid mixture and recover the washed ethylene gas to obtain the liquid product. The pressure in the first distillation column 5 is controlled at 20 kPa and the temperature at 130°C to distill the liquid product once to obtain the light fraction and the heavy fraction by-product. The light fraction enters the light fraction product splitter 10, and the distillation column split ratio is controlled at 100%, that is, 100% enters the second distillation column 6 and 0% enters the reaction device 3. The pressure in the second distillation column 6 is controlled at 40 kPa and the temperature at 150°C to distill the fraction twice to obtain norbornene. The pressure in the third distillation column 7 is controlled at 90 kPa and the temperature at 100°C to distill the heavy fraction twice to obtain the solvent and the heavy fraction. The heavy fraction enters the heavy fraction product splitter 11, and the split ratio in the fourth distillation column 8 is controlled at 80%, that is, 80% enters the fourth distillation column 8 and 20% enters the cracking column 12. The volume ratio of the high-boiling-point solvent (benzamide) to the heavy component was controlled at 1:6. The pressure inside the fourth distillation column 8 was controlled at 90 kPa and the temperature at 120 °C. The heavy component was distilled to obtain tetracyclododecene and polycyclopentadiene.

[0115] (3) The pressure inside the cracking tower 12 is controlled at 1300 kPa and the temperature at 230 °C. The heavy components are cracked to obtain norbornene and cyclopentadiene. Norbornene and cyclopentadiene enter the second distillation tower 6.

[0116] Example 10

[0117] In this embodiment, the molar ratio of ethylene to dicyclopentadiene is 30:1, the mass fraction of dicyclopentadiene in the organic solution is 35%, and the mass fraction of cyclopentadiene in both cyclopentadiene and dicyclopentadiene is 3%.

[0118] Norbornene in this embodiment is prepared through the following steps:

[0119] (1) Dicyclopentadiene, organic solvent (decane: n-dodecane = 1:1) and ethylene were added in sequence according to the ratio. Under stirring conditions, the temperature was increased to 400℃ and the pressure was increased to 1MPa. The reaction was held for 0.1h to obtain a gas-liquid mixture.

[0120] (2) The pressure in flash tank 4 is controlled at 800 kPa and the temperature at 120°C to separate the gas-liquid mixture and recover the washed ethylene gas to obtain the liquid product. The pressure in the first distillation column 5 is controlled at 19 kPa and the temperature at 110°C to distill the liquid product once to obtain the light fraction and the heavy fraction by-product. The light fraction enters the light fraction product splitter 10, and the distillation column split ratio is controlled at 100%, that is, 100% enters the second distillation column 6 and 0% enters the reaction device 3. The pressure in the second distillation column 6 is controlled at 30 kPa and the temperature at 130°C to distill the fraction twice to obtain norbornene. The pressure in the third distillation column 7 is controlled at 40 kPa and the temperature at 90°C to distill the heavy fraction twice to obtain the solvent and the heavy fraction. The heavy fraction enters the heavy fraction product splitter 11, and the split ratio in the fourth distillation column 8 is controlled at 50%, that is, 50% enters the fourth distillation column 8 and 50% enters the cracking column 12. The volume ratio of the high-boiling-point solvent (benzophenone) to the heavy component was controlled at 1:10. The pressure in the fourth distillation column was controlled at 40 kPa and the temperature at 110 °C. The heavy component was distilled to obtain tetracyclododecene and polycyclopentadiene.

[0121] (3) The pressure inside the cracking tower 12 is controlled at 1200 kPa and the temperature at 120 °C. The heavy components are cracked to obtain norbornene and cyclopentadiene. Norbornene and cyclopentadiene enter the second distillation tower.

[0122] Example 11

[0123] In this embodiment, the molar ratio of ethylene to dicyclopentadiene is 30:1, the mass fraction of dicyclopentadiene in the organic solution is 55%, and the mass fraction of cyclopentadiene in the total mass fraction of cyclopentadiene and dicyclopentadiene is 6%.

[0124] Norbornene in this embodiment is prepared through the following steps:

[0125] (1) Dicyclopentadiene, organic solvent (cyclohexane: methylcyclohexane = 1:2) and ethylene were added in sequence according to the ratio. Under stirring conditions, the temperature was increased to 320°C and the pressure was increased to 2MPa. The reaction was held for 0.2h to obtain a gas-liquid mixture.

[0126] (2) The pressure in flash tank 4 is controlled at 900 kPa and the temperature at 140°C to separate the gas-liquid mixture and recover the washed ethylene gas to obtain the liquid product. The pressure in the first distillation column 5 is controlled at 19 kPa and the temperature at 120°C to distill the liquid product once to obtain the light fraction and the heavy fraction by-product. The light fraction enters the light fraction product splitter 10, and the distillation column split ratio is controlled at 70%, that is, 70% enters the second distillation column 6 and 30% enters the reaction device 3. The pressure in the second distillation column 6 is controlled at 4 kPa and the temperature at 70°C to distill the fraction twice to obtain norbornene. The pressure in the third distillation column 7 is controlled at 85 kPa and the temperature at 170°C to distill the heavy fraction twice to obtain the solvent and the heavy fraction. The heavy fraction enters the heavy fraction product splitter 11, and the split ratio in the fourth distillation column 8 is controlled at 100%, that is, 100% enters the fourth distillation column 8 and 0% enters the cracking column 12. The volume ratio of the high-boiling-point solvent (diphenyl ether) to the heavy component was controlled at 1:3. The pressure inside the fourth distillation column 8 was controlled at 85 kPa and the temperature at 190 °C. The heavy component was distilled to obtain tetracyclododecene and polycyclopentadiene.

[0127] (3) The cracking tower 12 is not turned on and is not heated.

[0128] Example 12

[0129] In this embodiment, the molar ratio of ethylene to dicyclopentadiene is 30:1, the mass fraction of dicyclopentadiene in the organic solution is 60%, and the mass fraction of cyclopentadiene in the total mass fraction of cyclopentadiene and dicyclopentadiene is 2%.

[0130] Norbornene in this embodiment is prepared through the following steps:

[0131] (1) Add dicyclopentadiene, organic solvent (cyclohexane: decane = 2:1) and ethylene in sequence according to the ratio. Under stirring conditions, raise the temperature to 140°C and the pressure to 40 MPa. Let the reaction stand for 8 hours to obtain a gas-liquid mixture.

[0132] (2) The pressure in flash tank 4 is controlled at 1000 kPa and the temperature at 160°C to separate the gas-liquid mixture and recover the washed ethylene gas to obtain the liquid product. The pressure in the first distillation column 5 is controlled at 11 kPa and the temperature at 60°C to distill the liquid product once to obtain the light fraction and the heavy fraction by-product. The light fraction enters the light fraction product splitter 10, and the distillation column split ratio is controlled at 100%, that is, 100% enters the second distillation column 6 and 0% enters the reaction device 3. The pressure in the second distillation column 6 is controlled at 7 kPa and the temperature at 50°C to distill the fraction twice to obtain norbornene. The pressure in the third distillation column 7 is controlled at 80 kPa and the temperature at 160°C to distill the heavy fraction twice to obtain the solvent and the heavy fraction. The heavy fraction enters the heavy fraction product splitter 11, and the split ratio in the fourth distillation column 8 is controlled at 20%, that is, 20% enters the fourth distillation column 8 and 80% enters the cracking column 12. The volume ratio of the high-boiling-point solvent (benzamide) to the heavy component was controlled at 1:7. The pressure inside the fourth distillation column 8 was controlled at 80 kPa and the temperature at 180 °C. The heavy component was distilled to obtain tetracyclododecene and polycyclopentadiene.

[0133] (3) The pressure inside the cracking tower 12 is controlled at 1250 kPa and the temperature at 140 °C. The heavy components are cracked to obtain norbornene and cyclopentadiene. Norbornene and cyclopentadiene enter the second distillation tower.

[0134] To more intuitively illustrate the differences between Examples 1 to 12, the relevant parameters and operating conditions are recorded in Tables 1, 2, and 3 below.

[0135] Table 1 Relevant reaction parameter settings

[0136]

[0137] Table 1 Relevant Reaction Parameter Settings (Continued)

[0138]

[0139]

[0140] Table 2 Relevant Distillation Parameter Settings

[0141]

[0142] Table 3 Relevant pyrolysis parameter settings

[0143]

[0144] The calculations for Examples 1 to 12 above were performed as follows, and the results are recorded in Table 3 below.

[0145] In this embodiment of the invention, the conversion rate of dicyclopentadiene (including any small amount of dicyclopentadiene contained in the raw material, all calculated as dicyclopentadiene) is defined as:

[0146]

[0147] The yield of norbornene is defined as:

[0148]

[0149] The yield of tetracyclododecene is defined as:

[0150]

[0151] Table 4. Calculation results of data from Examples 1-12

[0152]

[0153] Combining the parameter settings and operating conditions in Tables 1, 2, and 3 with the calculation results in Table 4, it can be seen from Examples 1-12 that: using the method of the present invention for producing norbornene and tetracyclododecene, the conversion rate of dicyclopentadiene (DCPD) is not less than 88%, and the total yield of norbornene (NB) and tetracyclododecene (TCD) is not less than 94.5%, with the norbornene (NB) yield adjustable between 99.8% and 0%, and the tetracyclododecene (TCD) yield adjustable between 96.2% and 0%. This demonstrates that the production method of the present invention can flexibly adjust the production ratio of norbornene and tetracyclododecene, thereby producing cyclic olefin polymer raw materials with different composition ratios to produce different grades of cyclic olefin polymers, achieving superior economic benefits.

[0154] Taking Examples 1-6 as examples, the inventors prepared norbornene and tetracyclododecene using conventional production methods. Specifically, the processes of preparing tetracyclododecene using recycled norbornene and preparing norbornene from the cracked distillation fraction of tetracyclododecene were omitted. The production process flow chart is shown below. Figure 2 The light fraction obtained from the first distillation column 5 directly enters the second distillation column 6, and the heavy fraction obtained from the third distillation column 7 directly enters the fourth distillation column 8, thus making comparative examples 1 to 6. In comparative examples 1 to 6, the production ratio of norbornene and tetracyclododecene was not adjusted; they were simply produced under certain conditions.

[0155] Comparative Example 1

[0156] The difference from Example 1 is that the light distillate product splitter 10 and the heavy distillate product splitter 11 and the cracking tower 12 are removed. In step (2), the light distillate product obtained from the first distillation tower 5 directly enters the second distillation tower 6, and the heavy distillate product obtained from the third distillation tower 7 directly enters the fourth distillation tower 8. Step (3) is omitted.

[0157] Implementation principle: Refer to the appendix Figure 2 The prepared dicyclopentadiene and organic solvent are pumped from DCPD / CPD tank 2 into reaction device 3, and the flow rate is controlled by a flow meter at 0.083 L / min. The liquid level is monitored in real time by a level gauge. When the liquid level in reaction device 3 exceeds a certain height, reaction device 3 starts to automatically heat and stir. Ethylene tank 1 is opened and the required ethylene is continuously introduced. The temperature is raised to 280℃ and the pressure is raised to 3 MPa. The mixture is kept in reaction device 2 for 4 hours to obtain a gas-liquid mixture.

[0158] The gas-liquid mixture includes: ethylene, cyclopentadiene, dicyclopentadiene, norbornene, tetracyclododecene, polycyclopentadiene, and organic solvents.

[0159] When the liquid level in reaction device 3 is higher than 70%, the outlet of reaction device 3 is opened under motor adjustment to control the liquid level at 70%. The reaction liquid in reaction device 3 flows continuously out of the outlet into flash tower 4. In flash tower 4, the reaction mixture fed through the inlet undergoes gas-liquid separation. The separated unreacted ethylene comes into contact with the reaction solvent sprayed in the washing device at the top of the tower. The reaction solvent absorbs the unreacted cyclopentadiene and norbornene in the gas and mixes them with the reaction liquid to complete the gas-liquid separation.

[0160] The top outlet of the flash tank 4 is the gaseous product ethylene, which is recycled back to the reaction device 3 for reuse. The bottom outlet of the flash tank 4 is the liquid product, including cyclopentadiene, dicyclopentadiene, norbornene, tetracyclododecene, polycyclopentadiene, and organic solvents.

[0161] After gas-liquid separation, the bottom outlet of flash tank 4 is opened to allow the liquid product to enter the first distillation column 5, where light fraction containing norbornene, solvent, and cyclopentadiene and heavy fraction by-product are separated by distillation.

[0162] Among them, non-condensable ethylene is collected from the top of the second distillation column 6, cyclopentadiene is collected from the side stream for recycling, and norbornene is collected from the bottom of the column.

[0163] The light distillate is continuously fed into the second distillation column 6, stirred and heated, and norbornene is separated by distillation. The recovered cyclopentadiene is then recycled into the DCPD / CPD tank 2.

[0164] Heavy byproducts are continuously pumped from the first distillation column 5 into the third distillation column 7, where they are stirred and heated. The solvent is separated by distillation, and the recovered cyclopentadiene is collected in the DCPD / CPD tank 2. Heavy byproducts are collected from the bottom of the column and fed into the fourth distillation column 8. High-boiling-point solvent is pumped from the inert solvent storage tank 9 into the fourth distillation column 8 to prevent polymer buildup in the bottom of the column from clogging the pipes, which would hinder continuous production and even cause danger. Stirring and heating are used to separate tetracyclododecene by distillation, and polycyclopentadiene is collected from the bottom of the column.

[0165] In the third distillation column 7, the solvent is collected from the top, cyclopentadiene is collected from the side stream for recycling, and heavy components, including tetracyclododecene and polycyclopentadiene, are collected from the bottom. The heavy components are mixed with high-boiling-point solvent and enter the fourth distillation column 8. The tetracyclododecene is collected from the top of the fourth distillation column 8, and polycyclopentadiene is collected from the bottom.

[0166] Comparative Example 2

[0167] The difference from Example 2 is that the light distillate product splitter 10 and the heavy distillate product splitter 11 and the cracking tower 12 are removed. In step (2), the light distillate product obtained from the first distillation tower 5 directly enters the second distillation tower 6, and the heavy distillate product obtained from the third distillation tower 7 directly enters the fourth distillation tower 8. Step (3) is omitted.

[0168] Comparative Example 3

[0169] The difference from Example 3 is that the light distillate product splitter 10 and the heavy distillate product splitter 11 and the cracking tower 12 are removed. In step (2), the light distillate product obtained from the first distillation tower 5 directly enters the second distillation tower 6, and the heavy distillate product obtained from the third distillation tower 7 directly enters the fourth distillation tower 8. Step (3) is omitted.

[0170] Comparative Example 4

[0171] The difference from Example 4 is that the light distillate product splitter 10 and the heavy distillate product splitter 11 and the cracking tower 12 are removed. In step (2), the light distillate product obtained from the first distillation tower 5 directly enters the second distillation tower 6, and the heavy distillate product obtained from the third distillation tower 7 directly enters the fourth distillation tower 8. Step (3) is omitted.

[0172] Comparative Example 5

[0173] The difference from Example 5 is that the light distillate product splitter 10 and the heavy distillate product splitter 11 and the cracking tower 12 are removed. In step (2), the light distillate product obtained from the first distillation tower 5 directly enters the second distillation tower 6, and the heavy distillate product obtained from the third distillation tower 7 directly enters the fourth distillation tower 8. Step (3) is omitted.

[0174] Comparative Example 6

[0175] The difference from Example 6 is that the light distillate product splitter 10 and the heavy distillate product splitter 11 and the cracking tower 12 are removed. In step (2), the light distillate product obtained from the first distillation tower 5 directly enters the second distillation tower 6, and the heavy distillate product obtained from the third distillation tower 7 directly enters the fourth distillation tower 8. Step (3) is omitted.

[0176] To more intuitively illustrate the differences between Examples 1-6 and Comparative Examples 1-6, relevant parameters are recorded in Table 5 below. At the same time, the DCPD conversion rate and the yields of NB and TCD are calculated according to the above calculation formula, and the parameter settings and calculation results are recorded in Table 5 below.

[0177] Table 5. Relevant parameter settings and data calculation results

[0178]

[0179]

[0180] By comparing Examples 1-6 and Comparative Examples 1-6, and referring to the calculation data in Table 5, it can be seen that after setting a fixed product diversion ratio, the final yields of both NB and TCD products changed to some extent. In Examples 1, 2, and 5, the NB product diversion ratio was reduced, resulting in more TCD being produced during the production process, increasing the TCD yield and decreasing the NB yield. In particular, Example 5 reduced the NB product diversion ratio to 0% to maximize TCD production. In Examples 3, 4, and 6, the TCD product diversion ratio was reduced, resulting in more NB being produced during the production process, increasing the NB yield and decreasing the TCD yield. In particular, Example 3 reduced the TCD product diversion ratio to 0% to maximize NB production. Through Comparative Examples 1-6, the inventors believe that by adopting the technical solution of the present invention, the production ratio of NB and TCD can be adjusted by adjusting the product diversion ratio.

[0181] To further verify the role of the automatic adjustment of the fixed production ratio by the diversion device, the inventors used the technical solution of this invention to produce norbornene and tetracyclododecene. By setting the ratio of NB yield to TCD yield, Examples 13 to 18 were made. Using the above calculation formula, the data parameters shown in Table 6 below were obtained.

[0182] Table 6 Data parameters for Comparative Examples 1-6 and Examples 13-18

[0183]

[0184] By comparing Examples 13-18 and Comparative Examples 1-6, and referring to the data parameters in Table 6, it can be seen that the yields of NB and TCD products changed after setting a fixed production ratio. The splitting device automatically adjusted the splitting ratio according to the actual production situation. In Examples 13-15, it automatically reduced the NB product splitting ratio; in Examples 16-18, it automatically reduced the TCD product splitting ratio, thereby obtaining a fixed mass ratio of NB and TCD products. The specific ratio of cyclic olefins produced in this way can be directly adapted to specific grades of cyclic olefin polymers. Therefore, the inventors believe that the technical solution of this invention can flexibly control the production ratio of norbornene and tetracyclododecene.

[0185] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. All modifications or applications made in accordance with the above embodiments are within the scope of protection of this technical solution.

[0186] Although specific embodiments of the invention have been described in detail, those skilled in the art will understand that various modifications and substitutions can be made to those details based on all the teachings disclosed, and all such changes are within the scope of protection of this invention. The full scope of this invention is given by the appended claims and any equivalents thereof.

Claims

1. A method for producing norbornene and tetracyclododecene, characterized in that, The method includes the following steps: S1. An organic solution of mixed ethylene and dicyclopentadiene and / or cyclopentadiene is reacted in a reaction apparatus to obtain a gas-liquid mixture product. S2. The gas-liquid mixture obtained in S1 is subjected to flash evaporation separation to recover the gaseous product and obtain the liquid product. S3. In the first distillation column, the liquid product obtained in S2 is separated by distillation to obtain light distillate product I and bottom product. S4. The light distillate product I obtained in S3 is diverted to the second distillation column and / or reaction unit in a certain proportion; S5. In the second distillation column, the light fraction product I that was distilled off from S4 is separated by secondary distillation, and cyclopentadiene is recovered to obtain norbornene product; at the same time, in the third distillation column, the bottom product is separated by secondary distillation, cyclopentadiene is recovered, and solvent and heavy fraction products are obtained. S6. The heavy component products obtained in S5 are diverted to the cracking tower and the fourth distillation tower in proportion; S7. In the cracking tower, a solvent is added to the heavy fraction product that was separated in S6, and the product is distilled and separated to obtain light fraction product II, which is treated in the same way as in S4; a solvent is added to the fourth distillation tower, and the product is distilled and separated to obtain tetracyclododecene product. In S3, the bottom product includes solvent, cyclopentadiene, tetracyclododecene, and polycyclopentadiene.

2. The method for producing norbornene and tetracyclododecene according to claim 1, characterized in that, In S4, the fractional ratio of the light distillate product I can be arbitrarily adjusted from 0 to 100%; or adjusted according to the pre-set production ratio of the norbornene product and the tetracyclododecene product.

3. The method for producing norbornene and tetracyclododecene according to claim 1, characterized in that, In S6, the splitting ratio of the recombinant component product is adjusted according to the pre-set production ratio of the norbornene product and the tetracyclododecene product.

4. The method for producing norbornene and tetracyclododecene according to claim 1, characterized in that, In S1, the solvent of the organic solution is selected from one or more of cycloalkanes, alkanes, and aromatic organic solvents.

5. The method for producing norbornene and tetracyclododecene according to claim 4, characterized in that, In S1, the organic solvent is selected from one or more of cyclohexane, methylcyclohexane, decane, n-dodecane, and toluene.

6. The method for producing norbornene and tetracyclododecene according to claim 1, characterized in that, In S1, the molar ratio of ethylene to dicyclopentadiene and / or cyclopentadiene is 20:1 to 40:1, and the mass fraction of dicyclopentadiene and / or cyclopentadiene in the organic solution is 20 to 60%.

7. The method for producing norbornene and tetracyclododecene according to claim 6, characterized in that, In S1, the molar ratio of ethylene to dicyclopentadiene and / or cyclopentadiene is 25:1 to 35:1, and the mass fraction of dicyclopentadiene and / or cyclopentadiene in the organic solution is 30 to 50%.

8. The method for producing norbornene and tetracyclododecene according to claim 1, characterized in that, In S1, when both dicyclopentadiene and cyclopentadiene are used as raw materials, the mass fraction of cyclopentadiene is 2~10wt%.

9. The method for producing norbornene and tetracyclododecene according to claim 1, characterized in that, In S1, the reaction temperature is 100~400℃, the reaction pressure is 1~50MPa, and the reaction residence time is 0.1~10h.

10. The method for producing norbornene and tetracyclododecene according to claim 9, characterized in that, In S1, the reaction temperature is 170~320℃, the reaction pressure is 2~20MPa, and the reaction residence time is 0.2~5h.

11. The method for producing norbornene and tetracyclododecene according to claim 1, characterized in that, In S2, the separation temperature is 20~160℃ and the separation pressure is 100~1000kPa.

12. The method for producing norbornene and tetracyclododecene according to claim 11, characterized in that, In S2, the separation temperature is 40~100℃ and the separation pressure is 300~700kPa.

13. The method for producing norbornene and tetracyclododecene according to claim 1, characterized in that, The bottom temperature of the first distillation column is 60~130℃, and the distillation pressure is 10~20kPa; And / or, the reboiler temperature of the second distillation column is 40~150℃, and the distillation pressure is 1~40kPa; And / or, the reboiler temperature of the third distillation column is 70~180℃, and the distillation pressure is 30~100kPa; And / or, the bottom temperature of the fourth distillation column is 100~200℃, and the distillation pressure is 30~100kPa.

14. The method for producing norbornene and tetracyclododecene according to claim 1, Its features are, In S4, when the light distillate product I is split, the splitting temperature is set to 50~90℃.

15. The method for producing norbornene and tetracyclododecene according to claim 1, Its features are, In S6, when the recombinant product is split, the splitting temperature is set to 150~180℃.

16. The method for producing norbornene and tetracyclododecene according to claim 1, characterized in that, In S7, the solvent is a solvent with a boiling point higher than 250°C.

17. The method for producing norbornene and tetracyclododecene according to claim 16, characterized in that, In S7, the solvent with a boiling point above 250°C is selected from one or more of benzophenone, diphenyl ether, and benzamide.

18. The method for producing norbornene and tetracyclododecene according to claim 1, characterized in that, In S7, the volume ratio of the solvent to the recombinant product is 1:(3~10).

19. The method for producing norbornene and tetracyclododecene according to claim 1, characterized in that, In S7, the temperature of the bottom of the cracking tower is 120~270℃, and the pressure of the cracking distillation is 1200~1400kPa.

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