Production method of norbornene and tetracyclododecene

Abstract

The invention discloses a production method of norbornene and tetracyclododecene. The method comprises the following steps: reacting ethylene with dicyclopentadiene and / or cyclopentadiene at a certain temperature and pressure, carrying out gas-liquid separation, and carrying out gradient rectification on a liquid product mixture to obtain a norbornene product and a tetracyclododecene product, the excessive ethylene, the unreacted dicyclopentadiene and / or cyclopentadiene and the solvent are purified and then recycled. Particularly, a norbornene solution which is not rectified and purified is circulated to the reaction device, and the norbornene solution and cyclopentadiene are continuously subjected to a Diels-Alder reaction, so that the aim of producing the tetracyclododecene to the maximum extent is fulfilled; meanwhile, the tetracyclododecene solution can be cracked to generate norbornene and cyclopentadiene, so that the aim of producing the norbornene to the maximum extent is fulfilled. Therefore, the production proportion of the two products can be flexibly adjusted according to production requirements, the investment cost is reduced, and good economic benefits are achieved.

Description

Technical Field

[0001] The invention relates to a method for producing norbornene and tetracyclododecene. Background Art

[0002] Norbornene (NB) and tetracyclododecene (TCD) products are widely used in the synthesis of cycloolefin copolymers / polymers (COC / COP). Cycloolefin polymers have the advantages of low density, low hygroscopicity, 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 norbornene and tetracyclododecene synthesis processes.

[0003] The processes suitable for the industrial production of norbornene and its derivatives can be divided into two types: liquid phase reaction process and gas phase reaction process. In the liquid phase reaction process, cyclopentadiene (CPD) or dicyclopentadiene (DCPD) is in liquid state during the reaction process, and ethylene gas is dissolved in the liquid phase for addition reaction; in the gas phase reaction process, cyclopentadiene (CPD) or dicyclopentadiene (DCPD) is first heated to gasify it, and then mixed with ethylene gas and introduced into the reaction device for reaction. In the reaction, the generated norbornene (NB) is easy to further react with cyclopentadiene (CPD) to generate tetracyclododecene (TCD), and tetracyclododecene can also be used for the synthesis of cycloolefin copolymer (COC).

[0004] Chinese patent CN104692993A discloses a method for synthesizing norbornene through a microchannel reactor, using a microreactor with a characteristic size of 10 to 300 microns manufactured using precision machining technology. According to experiments, this method has high heat transfer efficiency, can quickly move reaction heat into and out of the system, avoid the generation of reaction hot spots, and effectively inhibit side reactions; high mass transfer efficiency and relatively safe, raw material conversion rate and norbornene selectivity are high, but the microchannel method is difficult to use in industrial-grade mass production of norbornene. Chinese patent CN102249839A discloses a method for synthesizing norbornene through a loop reactor, which has the advantages of pressure resistance and fast heat transfer, high safety, and can achieve a higher conversion rate of cyclopentadiene, but it is easy to produce more tetracyclododecene, and it is impossible to achieve the regulation of the production ratio of the two.

[0005] Japanese patent application JP3991650B2 provides a method for simultaneously producing NB and TCD. Ethylene, CPD and / or DCPD and NB are continuously supplied to a reaction device and reacted by heating. The reaction mixture is subjected to gas-liquid separation to separate unreacted ethylene and liquid reaction mixture, and the separated ethylene is contacted with a solvent to transfer the NB contained in the ethylene to the solvent and separate it. The ethylene is circulated to the reaction device. After contacting with ethylene, the solvent is mixed with the liquid reaction mixture, and a fraction containing NB, TCD and solvent is separated from the mixture, and then part of the NB is separated and recovered and circulated to the reaction device while heating. However, it simply produces and distills two products, and cannot solve the problem of regulating the ratio of tetracyclododecene and norbornene.

[0006] Japanese patent application JP5344808B2 provides a method for suppressing heavy byproducts to produce cyclic olefins such as TCD and NB. The production of heavy byproducts is reduced by storing DCPD under low temperature and low oxygen concentration conditions. The reaction device can add ethylene and DCPD and / or CPD to prepare norbornene, and can also add NB and CPD to prepare TCD, which has a certain degree of flexibility. However, it has no way to continuously prepare two cyclic olefins simultaneously in production.

[0007] Chinese patent application CN115433053A provides a method for the co-production of TCD and NB, wherein a DCPD solution and ethylene are reacted in a tubular reaction device to obtain a co-product of TCD and NB. The process of preparing NB is omitted, and specific process parameters are used to directly react DCPD and ethylene to produce TCD and NB at the same time. The NB concentration in the crude product is 47.68%, the TCD concentration is 43.03%, and the by-product concentration is only 1.02%. The crude product is distilled at atmospheric pressure to obtain NB with a purity of more than 99.8%, and further vacuum distillation is performed to obtain TCD with a purity of more than 99.5%. The co-production method provided by the invention simplifies the production process, omits the process of preparing NB, greatly reduces the equipment investment, energy consumption and unit consumption of production, and has a very low cost. However, it can only adjust the production ratio of NB and TCD by adjusting the reaction conditions, and cannot affect the output ratio without affecting the conditions of the reaction device; if a ratio error occurs during production, it cannot continuously monitor and adjust the production ratio during the production process.

[0008] Japanese patent JP4526142B2 separates the generated norbornene when using dicyclopentadiene and ethylene to prepare norbornene, with one part re-circulated and the other part produced as a product. In this process, the light fractions of norbornene and cyclopentadiene are distilled again, and cyclopentadiene and part of norbornene are recovered, which greatly improves the conversion rate of dicyclopentadiene.

[0009] Chinese patent CN115385769A discloses a method for reducing by-products by synthesizing tetracyclododecene from dicyclopentadiene, wherein a small amount of dicyclopentadiene solution is continuously added dropwise to a large amount of norbornene solutions, and the dicyclopentadiene added dropwise can be consumed immediately, so that norbornene and dicyclopentadiene can maintain a higher molar ratio, reduce the generation of polycyclopentadiene in the reaction, and the system uses ethylene atmosphere to suppress the decomposition of norbornene. This condition can produce tetracyclododecene of higher purity, and the process is simple and operable. However, the method norbornene needs to be used as a raw material, and reducing the concentration of dicyclopentadiene is not convenient for preparing norbornene and tetracyclododecene simultaneously.

[0010] Chinese patent CN105481625A uses two series-connected autoclave reactors, using two series-connected autoclave reactors, the temperature in the first reactor is lower and the residence time is shorter, and the temperature in the second reactor is higher and the residence time is longer. During the reaction, heat balance is achieved by the endothermic depolymerization of dicyclopentadiene and the exothermic reaction of diene, and the reaction is inhibited by high ethylene concentration and low cyclopentadiene concentration to change to the polymer direction, and the mass transfer heat is solved by full back mixing at the same time. However, there is no mention of how to solve the problem of the generated heavy by-products, and the productivity of norbornene is less than expected.

[0011] Chinese patent CN103664470A combines the mass transfer advantages of kettle reactors and the advantages of process stability and safe operation of tubular reactors under high pressure operating conditions. The yield of norbornene in the preparation method can reach 90-98%. However, although the method optimizes the reaction conditions and reduces the generation of by-products, the by-products obtained are not further processed, and the effect is also not as good as the inventor's expectations. However, compared with kettle reactors, when the production process of norbornene uses tubular reactors, more polymers will accumulate on the reactor wall, thereby affecting the economy and safety of the reactor. Summary of the invention

[0012] In order to at least partially solve the above technical problems existing in the prior art, the object of the present invention is to provide a production method that can flexibly adjust the ratio of norbornene to tetracyclododecene during the production process. The production method of the present invention uses a tank reactor to enable the equipment to operate stably for a long period of time, and the method can further improve the conversion rate of dicyclopentadiene and the selectivity of norbornene and tetracyclododecene.

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

[0014] S1, mixing ethylene with an organic solution of dicyclopentadiene and / or cyclopentadiene, and reacting them in a reaction device to obtain a gas-liquid mixed product;

[0015] S2, flashing and separating the gas-liquid mixed product obtained in S1, recovering the gas product, and obtaining a liquid product;

[0016] S3, in the first distillation tower, distilling and separating the liquid product obtained in S2 to obtain a light fraction product and a bottom product;

[0017] S4, dividing the light fraction product obtained in S3 into the second distillation tower and / or the reaction device in proportion;

[0018] S5, in a second distillation tower, secondary distilling and separating the light fraction product diverted in S4, recovering cyclopentadiene, and obtaining a norbornene product; at the same time, in a third distillation tower, secondary distilling and separating the bottom product, recovering cyclopentadiene, and obtaining a solvent and a heavy fraction product;

[0019] S6, dividing the heavy component product obtained in S5 into a cracking tower and / or a fourth distillation tower in proportion;

[0020] S7, in a cracking tower, adding a solvent to the heavy fraction product separated from S6, distilling and separating to obtain a light fraction product, and the light fraction product is treated in the same manner as S4; adding a solvent to a fourth distillation tower, distilling and separating to obtain a tetracyclododecene product;

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

[0022] In any specific embodiment, in S4, the split ratio of the light fraction product is arbitrarily adjusted between 0% and 100%; or adjusted according to the preset production ratio of the norbornene product and the tetracyclododecene product. In an embodiment of the present invention, when the distillation tower split ratio of the light fraction product is 0%, the second distillation tower is not opened and heated.

[0023] In any specific embodiment, in S6, the split ratio of the heavy component product is arbitrarily adjusted between 0% and 100%; or adjusted according to the preset production ratio of the norbornene product and the tetracyclododecene product. In the embodiment of the present invention, when the distillation tower split ratio of the heavy component product is 0%, the fourth distillation tower is not opened and heated; when the distillation tower split ratio of the heavy component product is 100%, the cracking tower is not opened and heated.

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

[0025] As a preferred technical solution 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 the ethylene to the dicyclopentadiene and / or cyclopentadiene (dicyclopentadiene is calculated as cyclopentadiene) is 20:1 to 40:1, and the mass fraction of the dicyclopentadiene and / or cyclopentadiene in the organic solution is 20 to 60%.

[0027] As a preferred technical solution of the present invention, the molar ratio of the ethylene to the 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 the 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 production raw materials, the mass fraction of cyclopentadiene is 2-10 wt %.

[0029] In any specific embodiment, in 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 technical solution of the present invention, in 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 S2, the separation temperature is 20-160° C., and the separation pressure is 100-1000 kPa.

[0032] As a preferred technical solution of the present invention, in 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 tower is 60-130° C., and the distillation pressure is 10-20 kPa;

[0034] and / or, the bottom temperature of the second distillation tower is 40-150° C., and the distillation pressure is 1-40 kPa;

[0035] And / or, the bottom temperature of the third distillation tower is 70-180° C., and the distillation pressure is 30-100 kPa;

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

[0037] In any specific embodiment, in S4, when splitting the light fraction product, the splitting insulation temperature is set to 50-90°C.

[0038] In any specific embodiment, in S6, when splitting the heavy component product, the splitting insulation temperature is set to 150-180°C.

[0039] In any specific embodiment, in S7, the solvent is a solvent having a boiling point higher than 250° C.; the solvent having 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 heavy component product is 1:(3-10).

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

[0042] The production method adopted by the present invention recovers part of norbornene and performs cracking and distillation on part of tetracyclododecene, thereby accurately controlling the production ratio of the two.

[0043] Based on the different proportions of components in the cycloolefin raw materials required for different brands of cycloolefin polymers, the present invention can flexibly produce cycloolefin polymer raw materials with different composition ratios to produce cycloolefin polymers of different brands by adjusting the production ratio of norbornene and tetracyclododecene.

[0044] The present invention reduces wastes that need to be processed by cracking and distilling heavy products, saves costs, and can achieve better economic benefits.

[0045] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[0049] The present invention will be further described below in conjunction with specific implementation modes, but the protection scope of the present invention is not limited by the following embodiments.

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

[0051] The inventors adopted the technical solution of the present invention to produce norbornene and tetracyclododecene, and prepared 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 cyclopentadiene and dicyclopentadiene is 2%;

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

[0055] (1) adding dicyclopentadiene, an organic solvent (cyclohexane: toluene = 1:1) and ethylene in order, raising the temperature to 280° C. and the pressure to 3 MPa under stirring conditions, and reacting for 4 hours to obtain a gas-liquid mixed product;

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

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

[0058] Implementation principle: Refer to the attached Figure 1 , the prepared dicyclopentadiene and organic solvent are pumped into the reaction device 3 in the DCPD / CPD tank 2, and the liquid level is detected in real time by a liquid level meter. When the liquid level of the reaction device 3 exceeds a certain height, the reaction device 3 starts to automatically heat and stir, the ethylene tank 1 is opened, the required ethylene is continuously introduced, the temperature is increased to 280°C, and it stays 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 an organic solvent;

[0060] When the liquid level of the reaction device 3 is higher than 70%, the outlet of the reaction device 3 is opened under the adjustment of the motor to control the liquid level at 70%. The reaction liquid in the reaction device 3 continuously flows out through the discharge port into the flash tank 4. In the flash tank 4, the reaction mixture sent through the feed port is subjected to gas-liquid separation, and the separated unreacted ethylene contacts the reaction solvent sprayed from the washing device at the top of the tower. The solvent absorbs the unreacted cyclopentadiene and norbornene in the gas and mixes with the reaction liquid to complete the gas-liquid separation;

[0061] Among them, the top discharge port of the flash tank 4 is the gas product - ethylene, and the ethylene gas is circulated to the reaction device 3 for recycling; the bottom discharge port of the flash tank 4 is the liquid product, including: cyclopentadiene, dicyclopentadiene, norbornene, tetracyclododecene, polycyclopentadiene, and organic solvent;

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

[0063] Among them, the light fraction products are taken out from the top of the first distillation tower, including: dicyclopentadiene, cyclopentadiene and norbornene; the heavy fraction by-products are taken out from the bottom of the first distillation tower;

[0064] The light fraction product is split in proportion, and the flow rate of the light fraction product is detected by a flow meter. The opening and closing sizes of the product valve and the reflux valve are adjusted by the light fraction product splitter 10, so that the light fraction is recycled into the reaction device 3 or enters the second distillation tower 6 in proportion; 20% of the light fraction is recycled into the reaction device 3, and the other 80% is continuously sent to the second distillation tower 6; if there is a light fraction entering the second distillation tower, it is stirred and heated, and the norbornene product is separated by distillation, and the cyclopentadiene is recovered and entered into the DCPD / CPD tank 2 for recycling; at the same time, the remaining solvent is discharged;

[0065] Among them, non-condensable ethylene is produced from the top of the second distillation tower, cyclopentadiene is produced from the side line for recycling, and norbornene product is produced from the bottom of the tower;

[0066] The heavy component by-product is continuously pumped from the first distillation tower 5 to the third distillation tower 7, stirred and heated, and the solvent is separated by distillation. The cyclopentadiene is recovered and enters the DCPD / CPD tank 2, and the heavy component is extracted from the bottom of the tower. The flow rate of the heavy component is detected by a flow meter, and the opening and closing size of the product valve and the reflux valve are adjusted by the heavy component product splitter 11, so that the heavy component enters the fourth distillation tower 8 or the cracking tower 12 in proportion; 100% of them enter the fourth distillation tower 8; if there is a heavy component entering the fourth distillation tower 8, the high boiling point solvent is pumped into the fourth distillation tower 8 from the inert solvent storage tank 9 to prevent the pipeline from being blocked when polymers accumulate in the tower bottom, which is not conducive to continuous production and may even cause danger. The mixture is stirred and heated, and tetracyclododecene is separated by distillation, and polycyclopentadiene is taken out from the bottom of the tower; the solvent is taken out from the top of the third distillation tower, cyclopentadiene is taken out from the side line for recycling, and heavy components including tetracyclododecene and polycyclopentadiene are taken out from the bottom of the tower, and the heavy components enter the fourth distillation tower; the tetracyclododecene product is taken out from the top of the fourth distillation tower, and polycyclopentadiene is taken out from the bottom of the tower.

[0067] If there are heavy components entering the cracking tower 12, they are mixed with the high boiling point solvent pumped from the inert solvent storage tank 9, stirred and heated, and cracked and distilled to obtain a crude norbornene product mixed with the light component product of the first distillation tower. Norbornene and cyclopentadiene are produced from the top of the cracking tower, and polycyclopentadiene is produced from the bottom of the tower.

[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 cyclopentadiene and dicyclopentadiene is 3%;

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

[0071] (1) adding dicyclopentadiene, an organic solvent (methylcyclohexane: toluene = 1:1) and ethylene in order according to the ratio, raising the temperature to 200° C. and the pressure to 9 MPa under stirring conditions, and reacting for 0.3 h to obtain a gas-liquid mixed product;

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

[0073] (3) The cracking tower 12 is not opened and 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 cyclopentadiene and dicyclopentadiene is 4%;

[0076] The norbornene of this embodiment is prepared by the following steps:

[0077] (1) adding dicyclopentadiene, an organic solvent (decane: toluene = 1:1) and ethylene in order according to the ratio, raising the temperature to 240° C. and the pressure to 15 MPa under stirring conditions, and reacting for 2 hours to obtain a gas-liquid mixed product;

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

[0079] (3) The pressure in the cracking tower 12 is controlled to be 1350 kPa and the temperature to be 240° C. to crack the heavy components and obtain norbornene and cyclopentadiene; the 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 cyclopentadiene and dicyclopentadiene is 10%;

[0082] The norbornene of this embodiment is prepared by the following steps:

[0083] (1) adding dicyclopentadiene, an organic solvent (cyclohexane: methylcyclohexane = 1:1) and ethylene in order according to the ratio, raising the temperature to 260° C. and the pressure to 5 MPa under stirring conditions, and reacting for 3 hours to obtain a gas-liquid mixed product;

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

[0085] (3) The pressure in the cracking tower 12 is controlled to be 1200 kPa and the temperature to be 180° C. to crack the heavy components and obtain norbornene and cyclopentadiene; the 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 cyclopentadiene and dicyclopentadiene is 9%;

[0088] The norbornene of this embodiment is prepared by the following steps:

[0089] (1) adding dicyclopentadiene, an organic solvent (cyclohexane: n-dodecane = 1:1) and ethylene in order according to the ratio, raising the temperature to 280° C. and the pressure to 6 MPa under stirring conditions, and reacting for 1 hour to obtain a gas-liquid mixed product;

[0090] (2) Control the pressure in the flash tank 4 to 650 kPa and the temperature to 70°C, separate the gas-liquid mixed product, recover the washed ethylene gas, and obtain the liquid product; control the pressure in the first distillation tower 5 to 18 kPa and the temperature to 100°C, distill the liquid product once to obtain the light fraction product and the heavy fraction by-product; the light fraction product enters the light fraction product splitter 10, and the diversion ratio of the distillation tower is controlled to be 0%, that is, 0% enters the second distillation tower 6, and 100% enters the reaction device 3; the second distillation tower 6 is not opened and heated. Control the pressure in the third distillation tower 7 to 75 kPa and the temperature to 140°C, and distill the heavy fraction product twice to obtain the solvent and the heavy fraction. The heavy fraction product enters the heavy fraction product splitter 11, and the diversion ratio of the fourth distillation tower 8 is controlled to be 100%, that is, 100% enters the fourth distillation tower 8, and 0% enters the cracking tower 12. The volume ratio of the high boiling point solvent (benzophenone:benzamide=1:1) to the heavy component is controlled to be 1:4, the pressure in the fourth distillation tower 8 is controlled to be 75 kPa, and the temperature is controlled to be 160° C., and the heavy component is distilled to obtain tetracyclododecene and polycyclopentadiene;

[0091] (3) The cracking tower 12 is not opened and 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 cyclopentadiene and dicyclopentadiene is 8%;

[0094] The norbornene of this embodiment is prepared by the following steps:

[0095] (1) adding dicyclopentadiene, an organic solvent (cyclohexane: methylcyclohexane = 1:1) and ethylene in order according to the ratio, raising the temperature to 220° C. and the pressure to 10 MPa under stirring conditions, and reacting for 7 hours to obtain a gas-liquid mixed product;

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

[0097] (3) The pressure in the cracking tower 12 is controlled to be 1280 kPa and the temperature to be 240° C. to crack the heavy components and obtain norbornene and cyclopentadiene; the 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 cyclopentadiene and dicyclopentadiene is 7%;

[0100] The norbornene of this embodiment is prepared by the following steps:

[0101] (1) adding dicyclopentadiene, an organic solvent (methylcyclohexane: n-dodecane = 1:1) and ethylene in order according to the ratio, raising the temperature to 100° C. and the pressure to 45 MPa under stirring conditions, and reacting for 10 hours to obtain a gas-liquid mixed product;

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

[0103] (3) The cracking tower 12 is not opened and 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 cyclopentadiene and dicyclopentadiene is 6%;

[0106] The norbornene of this embodiment is prepared by the following steps:

[0107] (1) adding dicyclopentadiene, an organic solvent (methylcyclohexane: decane = 1:1) and ethylene in order according to the ratio, raising the temperature to 100° C. and the pressure to 50 MPa under stirring conditions, and reacting for 8 hours to obtain a gas-liquid mixed product;

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

[0109] (3) The cracking tower 12 is not opened and 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 cyclopentadiene and dicyclopentadiene is 5%;

[0112] The norbornene of this embodiment is prepared by the following steps:

[0113] (1) adding dicyclopentadiene, an organic solvent (n-dodecane: toluene = 1:1) and ethylene in order according to the ratio, raising the temperature to 170° C. and the pressure to 35 MPa under stirring conditions, and reacting for 9 hours to obtain a gas-liquid mixed product;

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

[0115] (3) The pressure in the cracking tower 12 is controlled to be 1300 kPa and the temperature to be 230° C. to crack the heavy components and obtain norbornene and cyclopentadiene; the 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 the cyclopentadiene and dicyclopentadiene is 3%;

[0118] The norbornene of this embodiment is prepared by the following steps:

[0119] (1) adding dicyclopentadiene, an organic solvent (decane: n-dodecane = 1:1) and ethylene in order according to the ratio, raising the temperature to 400° C. and the pressure to 1 MPa under stirring conditions, and reacting for 0.1 h to obtain a gas-liquid mixed product;

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

[0121] (3) The pressure in the cracking tower 12 is controlled to be 1200 kPa and the temperature to be 120° C. to crack the heavy components and obtain norbornene and cyclopentadiene; the norbornene and cyclopentadiene enter the second distillation tower.

[0122] Embodiment 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 cyclopentadiene and dicyclopentadiene is 6%;

[0124] The norbornene of this embodiment is prepared by the following steps:

[0125] (1) adding dicyclopentadiene, an organic solvent (cyclohexane: methylcyclohexane = 1:2) and ethylene in order according to the ratio, raising the temperature to 320° C. and the pressure to 2 MPa under stirring conditions, and reacting for 0.2 h to obtain a gas-liquid mixed product;

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

[0127] (3) The cracking tower 12 is not opened and 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 cyclopentadiene and dicyclopentadiene is 2%;

[0130] The norbornene of this embodiment is prepared by the following steps:

[0131] (1) adding dicyclopentadiene, an organic solvent (cyclohexane: decane = 2:1) and ethylene in order according to the ratio, raising the temperature to 140° C. and the pressure to 40 MPa under stirring conditions, and reacting for 8 hours to obtain a gas-liquid mixed product;

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

[0133] (3) The pressure in the cracking tower 12 is controlled to be 1250 kPa and the temperature to be 140° C. to crack the heavy components and obtain norbornene and cyclopentadiene; the norbornene and cyclopentadiene enter the second distillation tower.

[0134] In order to more intuitively show 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 Related distillation parameter settings

[0141]

[0142] Table 3 Related pyrolysis parameter settings

[0143]

[0144] The following calculations were performed on the above Examples 1 to 12, and the calculation results are recorded in Table 3 below.

[0145] In the present embodiment, the conversion rate of dicyclopentadiene (including a small amount of cyclopentadiene 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 of Examples 1 to 12

[0152]

[0153] Combining the relevant parameter settings of Tables 1, 2, and 3, the operating conditions, and the calculation results of Table 4, it can be seen that: from Examples 1 to 12, it can be seen that: by adopting the method for producing norbornene and tetracyclododecene of the present invention, the conversion rate of dicyclopentadiene (DCPD) is not less than 88%, the total yield of norbornene (NB) and tetracyclododecene (TCD) is not less than 94.5%, and the yield of norbornene (NB) can be adjusted between 99.8% and 0%, and the yield of tetracyclododecene (TCD) can be adjusted between 96.2% and 0%. It can be explained that the production method of the present invention can flexibly adjust the production ratio of norbornene and tetracyclododecene, and then produce cycloolefin polymer raw materials with different composition ratios to produce cycloolefin polymers of different grades, which can achieve better economic benefits.

[0154] The inventors take Examples 1 to 6 as examples, and adopt a conventional production method to prepare norbornene and tetracyclododecene, that is, the process of using the recovered norbornene to prepare tetracyclododecene and the process of cracking and rectifying part of the tetracyclododecene to prepare norbornene are omitted in the steps. The production process flow chart is shown in Figure 2 , the light fraction product obtained from the first distillation tower 5 directly enters the second distillation tower 6, and the heavy fraction product obtained from the third distillation tower 7 directly enters the fourth distillation tower 8, making comparative examples 1 to 6. In comparative examples 1 to 6, the production ratio of norbornene and tetracyclododecene is not adjusted, and both are only produced under certain conditions.

[0155] Comparative Example 1

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

[0157] Implementation principle: Refer to the attached Figure 2 , the prepared dicyclopentadiene and organic solvent are pumped into the reaction device 3 in the DCPD / CPD tank 2, and the flow rate is controlled at 0.083L / min by a flow meter; the liquid level is detected in real time by a liquid level meter, and when the liquid level of the reaction device 3 exceeds a certain height, the reaction device 3 starts to automatically heat and stir, the ethylene tank 1 is opened, the required ethylene is continuously introduced, the temperature is increased to 280°C, the pressure is increased to 3MPa, and it stays in the reaction device 2 for 4h to obtain a gas-liquid mixture;

[0158] The gas-liquid mixture includes: ethylene, cyclopentadiene, dicyclopentadiene, norbornene, tetracyclododecene, polycyclopentadiene and an organic solvent;

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

[0160] Among them, the top discharge port of the flash tank 4 is the gas product - ethylene, and the ethylene gas is circulated to the reaction device 3 for recycling; the bottom discharge port of the flash tank 4 is the liquid product, including: cyclopentadiene, dicyclopentadiene, norbornene, tetracyclododecene, polycyclopentadiene, and organic solvent;

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

[0162] Among them, the second distillation tower 6 produces non-condensable ethylene at the top, produces cyclopentadiene at the side line for recycling, and produces norbornene product at the bottom;

[0163] The light fraction product is continuously fed into the second distillation tower 6, stirred and heated, and the norbornene is separated by distillation, and the cyclopentadiene is recovered and fed into the DCPD / CPD tank 2 for recycling;

[0164] The heavy by-product is continuously pumped from the first distillation tower 5 to the third distillation tower 7, stirred and heated, distilled to separate the solvent, recovered cyclopentadiene and entered the DCPD / CPD tank 2, the heavy product is extracted from the bottom of the tower and entered the fourth distillation tower 8, and the high boiling point solvent is pumped from the inert solvent storage tank 9 to the fourth distillation tower 8 to prevent the accumulation of polymers in the tower bottom from clogging the pipeline, which is not conducive to continuous production and may even cause danger. Stir and heat, distill and separate tetracyclododecene, and extract polycyclopentadiene from the bottom of the tower;

[0165] Among them, the solvent is produced from the top of the third distillation tower 7, cyclopentadiene is produced from the side line for recycling, and heavy components including tetracyclododecene and polycyclopentadiene are produced from the bottom of the tower. The heavy components are mixed with the high boiling point solvent and enter the fourth distillation tower 8; tetracyclododecene is produced from the top of the fourth distillation tower 8, and polycyclopentadiene is produced from the bottom of the tower.

[0166] Comparative Example 2

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

[0168] Comparative Example 3

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

[0170] Comparative Example 4

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

[0172] Comparative Example 5

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

[0174] Comparative Example 6

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

[0176] In order to more intuitively show the difference between Examples 1 to 6 and Comparative Examples 1 to 6, the 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 Related parameter settings and data calculation results

[0178]

[0179]

[0180] By comparing Examples 1 to 6 and Comparative Examples 1 to 6, combined with the calculated data in Table 5, it can be seen that after setting a fixed product diversion ratio, the final yields of the two products NB and TCD have changed to a certain extent. In Examples 1, 2, and 5, the product diversion ratio of NB is reduced, so that more TCD is produced during the production process, the yield of TCD is increased, and the yield of NB is reduced. In particular, in Example 5, the NB product diversion ratio is reduced to 0% to produce TCD in maximum quantity. In Examples 3, 4, and 6, the product diversion ratio of TCD is reduced, so that more NB is produced during the production process, the yield of NB is increased, and the yield of TCD is reduced. In particular, in Example 3, the TCD product diversion ratio is reduced to 0% to produce NB in ​​maximum quantity. Through Comparative Examples 1 to 6, the inventor believes 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] In order to further verify the role of the diversion device in automatically adjusting the fixed production ratio, the inventors adopted the technical solution of the present invention to produce norbornene and tetracyclododecene. By setting the ratio of NB yield to TCD yield, Examples 13 to 18 were prepared. Using the above calculation formula, the data parameters shown in Table 6 below were obtained.

[0182] Table 6 Data parameters of Comparative Examples 1 to 6 and Examples 13 to 18

[0183]

[0184] By comparing Examples 13 to 18 and Comparative Examples 1 to 6, combined with the data parameters in Table 6, it can be seen that after setting a fixed production ratio, the final yields of the two products NB and TCD have changed. The splitter automatically adjusts the split ratio according to the actual production situation. In Examples 13 to 15, the product split ratio of NB is automatically adjusted to reduce the split ratio, and in Examples 16 to 18, the product split ratio of TCD is automatically adjusted to reduce the split ratio, so that NB and TCD products with a fixed mass ratio can be obtained, and the specific ratio of cycloolefins produced thereby can be directly adapted to a specific grade of cycloolefin polymers. Therefore, the inventor believes that the technical solution of the present invention can flexibly regulate the production ratio of norbornene and tetracyclododecene.

[0185] The above are only preferred feasible embodiments of the present invention, and the protection scope of the present invention is not limited thereto. Various modifications or applications made according to the above embodiments are within the protection scope of this technical solution.

[0186] Although the specific embodiments of the present invention have been described in detail, it will be understood by those skilled in the art. According to all the teachings disclosed, various modifications and replacements can be made to those details, and these changes are all within the protection scope of the present invention. The full scope of the present invention is given by the attached claims and any equivalents thereof.

Claims

1. A method for producing norbornene and tetracyclododecene, characterized in that: The method comprises the following steps: S1, mixing ethylene with an organic solution of dicyclopentadiene and / or cyclopentadiene, and reacting them in a reaction device to obtain a gas-liquid mixed product; S2, flashing and separating the gas-liquid mixed product obtained in S1, recovering the gas product, and obtaining a liquid product; S3, in the first distillation tower, distilling and separating the liquid product obtained in S2 to obtain a light fraction product and a bottom product; S4, dividing the light fraction product obtained in S3 into the second distillation tower and / or the reaction device in proportion; S5, in a second distillation tower, secondary distilling and separating the light fraction product separated in S4, recovering cyclopentadiene, and obtaining a norbornene product; at the same time, in a third distillation tower, secondary distilling and separating the bottom product, recovering cyclopentadiene, and obtaining a solvent and a heavy fraction product; S6, dividing the heavy component product obtained in S5 into a cracking tower and / or a fourth distillation tower in proportion; S7, in a cracking tower, adding a solvent to the heavy fraction product separated from S6, distilling and separating to obtain a light fraction product, and the light fraction product is treated in the same manner as S4; adding a solvent to a fourth distillation tower, distilling and separating to obtain a tetracyclododecene product; Wherein, 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 diversion ratio of the light fraction product is arbitrarily adjusted between 0% and 100%; or adjusted according to a preset production ratio of the norbornene product to the tetracyclododecene product.

3. The method for producing norbornene and tetracyclododecene according to claim 1, characterized in that: In S6, the diversion ratio of the heavy component product is arbitrarily adjusted between 0% and 100%; or adjusted according to a preset 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 cycloalkane, alkane, and aromatic organic solvents; Preferably, the organic solvent is selected from one or more of cyclohexane, methylcyclohexane, decane, n-dodecane and toluene.

5. The method for producing norbornene and tetracyclododecene according to claim 1, characterized in that: In S1, the molar ratio of the ethylene to the dicyclopentadiene and / or cyclopentadiene is 20:1 to 40:1, and the mass fraction of the dicyclopentadiene and / or cyclopentadiene in the organic solution is 20 to 60%; Preferably, the molar ratio of the ethylene to the dicyclopentadiene and / or cyclopentadiene is 25:1 to 35:1, and the mass fraction of the dicyclopentadiene and / or cyclopentadiene in the organic solution is 30 to 50%.

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

7. The method for producing norbornene and tetracyclododecene according to claim 1, characterized in that: In 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; Preferably, in 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.

8. The method for producing norbornene and tetracyclododecene according to claim 1, characterized in that: In said S2, the separation temperature is 20-160°C, and the separation pressure is 100-1000 kPa; Preferably, in S2, the separation temperature is 40-100°C, and the separation pressure is 300-700 kPa.

9. The method for producing norbornene and tetracyclododecene according to claim 1, characterized in that: The bottom temperature of the first distillation tower is 60-130°C, and the distillation pressure is 10-20 kPa; and / or, the bottom temperature of the second distillation tower is 40-150° C., and the distillation pressure is 1-40 kPa; And / or, the bottom temperature of the third distillation tower is 70-180° C., and the distillation pressure is 30-100 kPa; And / or, the bottom temperature of the fourth distillation tower is 100-200° C., and the distillation pressure is 30-100 kPa.

10. The method for producing norbornene and tetracyclododecene according to claim 1, characterized in that: In S4, when splitting the light fraction product, the splitting insulation temperature is set to 50-90°C.

11. The method for producing norbornene and tetracyclododecene according to claim 1, characterized in that: In S6, when splitting the heavy component product, the splitting insulation temperature is set to 150-180°C.

12. The method for producing norbornene and tetracyclododecene according to claim 1, characterized in that: In S7, the solvent is a solvent having a boiling point higher than 250°C; Preferably, the solvent having a boiling point higher than 250° C. is selected from one or more of benzophenone, diphenyl ether and benzamide.

13. The method for producing norbornene and tetracyclododecene according to claim 1 or 13, characterized in that: In S7, the volume ratio of the solvent to the heavy component product is 1:(3-10).

14. The method for producing norbornene and tetracyclododecene according to claim 1, characterized in that: In S7, the temperature of the cracking tower kettle is 120-270°C, and the pressure of the cracking distillation is 1200-1400 kPa.

Images