Preparation method of tetracyclododecene

Abstract

The invention discloses a preparation method of tetracyclododecene, which comprises the following steps: mixing crude dicyclopentadiene, a norbornene solution and ethylene as raw materials, carrying out Diels-Alder reaction, and carrying out three-section rectification on the generated product to obtain a high-purity tetracyclododecene product and a heavy oil byproduct. Compared with the prior art, the method has the advantages that the dicyclopentadiene with the impurity content of less than or equal to 15% can be used as a raw material, so that high-purity dicyclopentadiene does not need to be purchased or crude dicyclopentadiene does not need to be refined. In addition, three-section rectification is used in the rectification section, so that the cost and the energy consumption can be effectively reduced.

Description

Technical Field

[0001] The invention relates to the field of synthesis of cycloolefin monomers, and in particular to a method for preparing tetracyclododecene. Background Art

[0002] Tetracyclododecene is a cycloolefin monomer that can be used to produce cycloolefin copolymers (COC) and cycloolefin polymers (COP). COC / COP is an amorphous transparent material with excellent moisture resistance, chemical resistance, electrical properties and optical balance. It is widely used in the fields of medicine, pharmaceuticals, packaging, electronic components and optical materials.

[0003] In patent JP069437A, Mitsui Chemicals reported a process for preparing tetracyclododecene. In this patent, only two stages of distillation are needed in the distillation process to obtain high-purity tetracyclododecene. However, the purity of dicyclopentadiene in the raw material used in this process needs to reach more than 95wt%.

[0004] In addition, in patent JP5344808B2, Mitsui Chemicals also proposed that even if the raw material is more than 95wt% dicyclopentadiene, its preservation before production is also very important. Specifically, the dicyclopentadiene is solidified into a solid state and stored at a temperature below 35°C, an oxygen concentration below 10ppm, and containing 20 to 10000ppm of stabilizer.

[0005] Unlike Mitsui Chemicals, in patent US6465703B1, Innosilicon Corporation mentioned that crude dicyclopentadiene with an impurity content of 10% or slightly higher can be used as a raw material to produce high-purity tetracyclododecene. Although the quality requirements for the raw materials are lowered, in order to produce qualified tetracyclododecene products, the process uses four-stage distillation in the distillation section.

[0006] In summary, if high-purity dicyclopentadiene is used as raw material, though the number of rectifying towers in the rectification section can be reduced, the dicyclopentadiene obtained by the carbon five fraction needs to be refined, or the dicyclopentadiene raw material that meets the requirements is purchased. If the dicyclopentadiene with lower purity is used as raw material, the equipment cost, operating cost and energy consumption in the rectification section will be greatly improved. The price of high-purity dicyclopentadiene in the current market is much higher than crude dicyclopentadiene, and it is not cost-effective to increase the high-purity dicyclopentadiene refining device simply for producing tetracyclododecene. Therefore, in order to reduce raw material cost, equipment cost and energy consumption, a design can utilize crude dicyclopentadiene as raw material, and the technology with relatively low equipment cost and energy consumption simultaneously to prepare tetracyclododecene will be of great significance. Summary of the invention

[0007] In view of the deficiencies in the above-mentioned prior art, the present invention provides a preparation method for preparing tetracyclododecene using crude dicyclopentadiene as a raw material and adopting three-stage distillation in the distillation section. While obtaining high-purity tetracyclododecene, the cost and energy consumption can be greatly reduced.

[0008] The present invention provides a method for preparing tetracyclododecene, comprising the following steps:

[0009] S1: Using crude dicyclopentadiene, norbornene solution and ethylene as raw materials, firstly sending dicyclopentadiene and norbornene solution to a mixer, then increasing the pressure of ethylene to the required pressure through a compressor and sending it to the mixer, and then preheating the raw materials in the mixer and sending them to a reactor for Diels-Alder reaction to obtain a crude tetracyclododecene product; wherein the impurity content of the crude dicyclopentadiene is ≤15%;

[0010] S2: The crude tetracyclododecene product obtained in step S1 is subjected to three-stage distillation in a first distillation tower, a second distillation tower and a third distillation tower respectively to obtain a high-purity tetracyclododecene product.

[0011] Preferably, in step S1, the impurities contained in the crude dicyclopentadiene include but are not limited to one or more of methyldicyclopentadiene, isobutylene, p-methylstyrene or naphthalene.

[0012] Preferably, in step S1, the impurity content of the crude dicyclopentadiene is less than 10%.

[0013] Preferably, in step S1, the solvent of the norbornene solution is an aromatic solvent such as toluene, xylene, ethylbenzene, or any combination of one or more aliphatic solvents such as ethylcyclopentane, dimethylcyclopentane, etc.; the mass concentration of norbornene in the norbornene solution is 10-90%.

[0014] Preferably, in step S1, the mass concentration of norbornene in the norbornene solution is 30-90%.

[0015] Preferably, in step S1, the purity of the ethylene is ≥99%.

[0016] Preferably, in step S1, the molar ratio of the crude dicyclopentadiene to norbornene is 1:(1-15).

[0017] Preferably, in step S1, the molar ratio of crude dicyclopentadiene to ethylene is 1:(5-20).

[0018] Preferably, in step S1, the mixer has a rotation speed of 500 to 2200 r / min and a stirring time of 1 to 60 min.

[0019] Preferably, in step S1, the preheating temperature of the mixed preheating is 150-190°C.

[0020] Preferably, in step S1, the reaction temperature in the reactor is 220-260° C., the reaction pressure is 1.0-5.0 MPa, the reaction time is 0.1-3 h, and the crude tetracyclododecene product obtained after the reaction is sent to the first distillation tower.

[0021] Preferably, in step S2, the first stage of distillation is completed in the first distillation tower, the raw material is the crude tetracyclododecene product obtained in step S1, the distillation process is atmospheric distillation, the tower top temperature is set to 30-45°C, the tower bottom temperature is set to 60-80°C, the first tower bottom liquid is obtained, and sent to the second distillation tower, and the unreacted ethylene is recovered and sent back to the ethylene feed pipeline.

[0022] Preferably, in step S2, the second stage of distillation is completed in the second distillation tower, the raw material is the first tower bottom liquid, the distillation process is atmospheric distillation, the tower top temperature is set to 90-140°C, the tower bottom temperature is set to 130-180°C, the second tower bottom liquid is obtained, and it is sent to the third distillation tower, and the unreacted dicyclopentadiene and norbornene solution are recovered and sent back to the feed pipeline of dicyclopentadiene and norbornene.

[0023] Preferably, in step S2, the third stage of distillation is completed in the third distillation tower, the raw material is the second tower bottom liquid, the distillation process is vacuum distillation, the tower top pressure is set to 0.2-0.6 kPa, the tower top temperature is set to 65-135°C, the tower bottom pressure is set to 1-15 kPa, the tower bottom temperature is set to 90-160°C, a high-purity tetracyclododecene product is obtained at the tower top, and a heavy oil by-product is obtained at the tower bottom.

[0024] Compared with the prior art, the technical effects of the present invention are as follows:

[0025] (1) Using crude dicyclopentadiene with an impurity content of ≤15% as raw material, the raw material cost is greatly reduced compared with the high-purity dicyclopentadiene raw material in the prior art;

[0026] (2) The three-stage distillation preparation method is adopted in the distillation stage, which greatly reduces the cost and energy consumption compared with the four-stage and five-stage distillation preparation methods in the prior art.

[0027] (3) The norbornene obtained in the second distillation tower and dicyclopentadiene with a purity higher than that of the raw material enter the reaction circulation system, thereby improving the purity of the dicyclopentadiene entering the reactor and also improving the distillation effect.

[0028] (4) In summary, the present invention provides a method for preparing tetracyclododecene using crude dicyclopentadiene as a raw material and adopting three-stage distillation in the distillation stage. While obtaining high-purity tetracyclododecene, the cost and energy consumption can be greatly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The figure is a schematic diagram of the process flow for synthesizing tetracyclododecene according to the present invention. DETAILED DESCRIPTION

[0030] The exemplary embodiments of the present invention are described in detail below. Although these exemplary embodiments are described in sufficient detail to enable those skilled in the art to implement the present invention, it should be understood that other embodiments can be implemented and various changes can be made to the present invention without departing from the spirit and scope of the present invention. The principles and features of the present invention are described below in conjunction with the accompanying drawings and specific embodiments, and the examples are only used to explain the present invention and are not used to limit the scope of the present invention.

[0031] In the embodiments and comparative examples of the present invention, the components of the substances were determined using Agilent's GC 7588 gas chromatograph.

[0032] Example 1

[0033] The impurity content of crude dicyclopentadiene is 15wt%, the concentration of norbornene solution is 80wt%, and the solvent is toluene. The molar ratio of crude dicyclopentadiene to norbornene is 1:8, and the molar ratio of crude dicyclopentadiene to ethylene is 1:10. Crude dicyclopentadiene, norbornene, toluene and ethylene are mixed in a mixer, preheated to 160°C and then fed into a reactor. The reaction pressure is set to 3MPa, the temperature is 220°C, and the reaction residence time is 10min.

[0034] After the reaction is completed, the crude product is sent to the first distillation tower. The top temperature of the first distillation tower is set at 40°C, the bottom temperature is set at 65°C, the top product returns to the reactor, and the bottom product is sent to the second distillation tower. The top temperature of the second distillation tower is set at 120°C, the bottom temperature is set at 170°C, the top product returns to the reactor, and the bottom product is sent to the third distillation tower. The third distillation tower is a vacuum distillation tower with a top pressure set at 0.3kPa, a set temperature of 120°C, a bottom pressure set at 10kPa, and a set temperature of 95°C. Tetracyclododecene is produced at the top of the tower, and a high-boiling point by-product is obtained in the bottom.

[0035] The results of gas chromatography analysis showed that the conversion rate of dicyclopentadiene was 87%, the purity of tetracyclododecene product was 99%, and the yield was 72%.

[0036] Example 2

[0037] The impurity content of crude dicyclopentadiene is 15wt%, the concentration of norbornene solution is 80wt%, and the solvent is toluene. The molar ratio of crude dicyclopentadiene to norbornene is 1:1, and the molar ratio of crude dicyclopentadiene to ethylene is 1:20. Crude dicyclopentadiene, norbornene, toluene and ethylene are mixed in a mixer, preheated to 160°C and then fed into a reactor. The reaction pressure is set to 2MPa, the temperature is 220°C, and the reaction residence time is 10min.

[0038] After the reaction is completed, the crude product is sent to the first distillation tower. The top temperature of the first distillation tower is set at 30°C, the bottom temperature is set at 60°C, the top product returns to the reactor, and the bottom product is sent to the second distillation tower. The top temperature of the second distillation tower is set at 90°C, the bottom temperature is set at 130°C, the top product returns to the reactor, and the bottom product is sent to the third distillation tower. The third distillation tower is a vacuum distillation tower with a top pressure set at 0.2kPa, a set temperature of 135°C, a bottom pressure set at 1kPa, and a set temperature of 160°C. Tetracyclododecene is produced at the top of the tower, and a high-boiling point by-product is obtained in the bottom.

[0039] The results of gas chromatography analysis showed that the conversion rate of dicyclopentadiene was 84%, the purity of tetracyclododecene product was 99%, and the yield was 70%.

[0040] Example 3

[0041] The impurity content of crude dicyclopentadiene is 14wt%, the concentration of norbornene solution is 80wt%, and the solvent is xylene. The molar ratio of crude dicyclopentadiene to norbornene is 1:15, and the molar ratio of crude dicyclopentadiene to ethylene is 1:5. Crude dicyclopentadiene, norbornene, xylene and ethylene are mixed in a mixer, preheated to 150°C and then fed into a reactor. The reaction pressure is set to 4MPa, the temperature is 220°C, and the reaction residence time is 10min.

[0042] After the reaction is completed, the crude product is sent to the first distillation tower. The top temperature of the first distillation tower is set at 45°C, the bottom temperature is set at 80°C, the top product returns to the reactor, and the bottom product is sent to the second distillation tower. The top temperature of the second distillation tower is set at 140°C, the bottom temperature is set at 180°C, the top product returns to the reactor, and the bottom product is sent to the third distillation tower. The third distillation tower is a vacuum distillation tower with a top pressure set at 0.6kPa, a set temperature of 65°C, a bottom pressure set at 15kPa, and a set temperature of 90°C. Tetracyclododecene is produced at the top of the tower, and a high-boiling point by-product is obtained in the bottom.

[0043] The results of gas chromatography analysis showed that the conversion rate of dicyclopentadiene was 88%, the purity of tetracyclododecene product was 99%, and the yield was 76%.

[0044] Example 4

[0045] The impurity content of crude dicyclopentadiene is 13wt%, the concentration of norbornene solution is 80wt%, and the solvent is ethylbenzene. The molar ratio of crude dicyclopentadiene to norbornene is 1:10, and the molar ratio of crude dicyclopentadiene to ethylene is 1:15. Crude dicyclopentadiene, norbornene, ethylbenzene and ethylene are mixed in a mixer, preheated to 190°C and then fed into a reactor. The reaction pressure is set to 3MPa, the temperature is 230°C, and the reaction residence time is 10min.

[0046] After the reaction is completed, the crude product is sent to the first distillation tower. The top temperature of the first distillation tower is set at 35°C, the bottom temperature is set at 70°C, the top product returns to the reactor, and the bottom product is sent to the second distillation tower. The top temperature of the second distillation tower is set at 100°C, the bottom temperature is set at 150°C, the top product returns to the reactor, and the bottom product is sent to the third distillation tower. The third distillation tower is a vacuum distillation tower with a top pressure set at 0.4kPa, a set temperature of 100°C, a bottom pressure set at 5kPa, and a set temperature of 120°C. Tetracyclododecene is produced at the top of the tower, and a high-boiling point by-product is obtained at the bottom.

[0047] The results of gas chromatography analysis showed that the conversion rate of dicyclopentadiene was 87%, the purity of tetracyclododecene product was 99%, and the yield was 74%.

[0048] Example 5

[0049] The impurity content of crude dicyclopentadiene is 12wt%, the concentration of norbornene solution is 90wt%, and the solvent is toluene. The molar ratio of crude dicyclopentadiene to norbornene is 1:8, and the molar ratio of crude dicyclopentadiene to ethylene is 1:10. Crude dicyclopentadiene, norbornene, toluene and ethylene are mixed in a mixer, preheated to 180°C and then fed into a reactor. The reaction pressure is set to 3MPa, the temperature is 240°C, and the reaction residence time is 6min.

[0050] After the reaction is completed, the crude product is sent to the first distillation tower. The top temperature of the first distillation tower is set at 40°C, the bottom temperature is set at 65°C, the top product returns to the reactor, and the bottom product is sent to the second distillation tower. The top temperature of the second distillation tower is set at 120°C, the bottom temperature is set at 170°C, the top product returns to the reactor, and the bottom product is sent to the third distillation tower. The third distillation tower is a vacuum distillation tower with a top pressure set at 0.3kPa, a set temperature of 120°C, a bottom pressure set at 10kPa, and a set temperature of 95°C. Tetracyclododecene is produced at the top of the tower, and a high-boiling point by-product is obtained in the bottom.

[0051] The results of gas chromatography analysis showed that the conversion rate of dicyclopentadiene was 91%, the purity of tetracyclododecene product was 99%, and the yield was 77%.

[0052] Example 6

[0053] The impurity content of crude dicyclopentadiene is 11wt%, the concentration of norbornene solution is 50wt%, and the solvent is toluene. The molar ratio of crude dicyclopentadiene to norbornene is 1:8, and the molar ratio of crude dicyclopentadiene to ethylene is 1:10. Crude dicyclopentadiene, norbornene, toluene and ethylene are mixed in a mixer, preheated to 160°C and then fed into a reactor. The reaction pressure is set to 1MPa, the temperature is 260°C, and the reaction residence time is 5min.

[0054] After the reaction is completed, the crude product is sent to the first distillation tower. The top temperature of the first distillation tower is set at 40°C, the bottom temperature is set at 65°C, the top product returns to the reactor, and the bottom product is sent to the second distillation tower. The top temperature of the second distillation tower is set at 120°C, the bottom temperature is set at 170°C, the top product returns to the reactor, and the bottom product is sent to the third distillation tower. The third distillation tower is a vacuum distillation tower with a top pressure set at 0.3kPa, a set temperature of 120°C, a bottom pressure set at 10kPa, and a set temperature of 95°C. Tetracyclododecene is produced at the top of the tower, and a high-boiling point by-product is obtained in the bottom.

[0055] The results of gas chromatography analysis showed that the conversion rate of dicyclopentadiene was 84%, the purity of tetracyclododecene product was 99%, and the yield was 76%.

[0056] Example 7

[0057] The impurity content of crude dicyclopentadiene is 10wt%, the concentration of norbornene solution is 10wt%, and the solvent is toluene. The molar ratio of crude dicyclopentadiene to norbornene is 1:8, and the molar ratio of crude dicyclopentadiene to ethylene is 1:10. Crude dicyclopentadiene, norbornene, toluene and ethylene are mixed in a mixer, preheated to 160°C and then fed into a reactor. The reaction pressure is set to 5MPa, the temperature is 250°C, and the reaction residence time is 30min.

[0058] After the reaction is completed, the crude product is sent to the first distillation tower. The top temperature of the first distillation tower is set at 40°C, the bottom temperature is set at 65°C, the top product returns to the reactor, and the bottom product is sent to the second distillation tower. The top temperature of the second distillation tower is set at 120°C, the bottom temperature is set at 170°C, the top product returns to the reactor, and the bottom product is sent to the third distillation tower. The third distillation tower is a vacuum distillation tower with a top pressure set at 0.3kPa, a set temperature of 120°C, a bottom pressure set at 10kPa, and a set temperature of 95°C. Tetracyclododecene is produced at the top of the tower, and a high-boiling point by-product is obtained in the bottom.

[0059] The results of gas chromatography analysis showed that the conversion rate of dicyclopentadiene was 79%, the purity of tetracyclododecene product was 99%, and the yield was 67%.

[0060] Example 8

[0061] The impurity content of crude dicyclopentadiene is 9wt%, the concentration of norbornene solution is 30wt%, and the solvent is ethylcyclopentane. The molar ratio of crude dicyclopentadiene to norbornene is 1:8, and the molar ratio of crude dicyclopentadiene to ethylene is 1:10. Crude dicyclopentadiene, norbornene, ethylcyclopentane and ethylene are mixed in a mixer, preheated to 160°C and then fed into a reactor. The reaction pressure is set to 3MPa, the temperature is 220°C, and the reaction residence time is 180min.

[0062] After the reaction is completed, the crude product is sent to the first distillation tower. The top temperature of the first distillation tower is set at 40°C, the bottom temperature is set at 65°C, the top product returns to the reactor, and the bottom product is sent to the second distillation tower. The top temperature of the second distillation tower is set at 120°C, the bottom temperature is set at 170°C, the top product returns to the reactor, and the bottom product is sent to the third distillation tower. The third distillation tower is a vacuum distillation tower with a top pressure set at 0.3kPa, a set temperature of 120°C, a bottom pressure set at 10kPa, and a set temperature of 95°C. Tetracyclododecene is produced at the top of the tower, and a high-boiling point by-product is obtained in the bottom.

[0063] The results of gas chromatography analysis showed that the conversion rate of dicyclopentadiene was 86%, the purity of tetracyclododecene product was 99%, and the yield was 72%.

[0064] Example 9

[0065] The impurity content of crude dicyclopentadiene is 9wt%, the concentration of norbornene solution is 80wt%, and the solvent is dimethylcyclopentane. The molar ratio of crude dicyclopentadiene to norbornene is 1:8, and the molar ratio of crude dicyclopentadiene to ethylene is 1:10. Crude dicyclopentadiene, norbornene, dimethylcyclopentane and ethylene are mixed in a mixer, preheated to 160°C and then fed into a reactor. The reaction pressure is set to 3MPa, the temperature is 220°C, and the reaction residence time is 10min.

[0066] After the reaction is completed, the crude product is sent to the first distillation tower. The top temperature of the first distillation tower is set at 40°C, the bottom temperature is set at 65°C, the top product returns to the reactor, and the bottom product is sent to the second distillation tower. The top temperature of the second distillation tower is set at 120°C, the bottom temperature is set at 170°C, the top product returns to the reactor, and the bottom product is sent to the third distillation tower. The third distillation tower is a vacuum distillation tower with a top pressure set at 0.3kPa, a set temperature of 120°C, a bottom pressure set at 10kPa, and a set temperature of 95°C. Tetracyclododecene is produced at the top of the tower, and a high-boiling point by-product is obtained in the bottom.

[0067] The results of gas chromatography analysis showed that the conversion rate of dicyclopentadiene was 87%, the purity of tetracyclododecene product was 99%, and the yield was 72%.

[0068] Comparative Example 1

[0069] The impurity content of crude dicyclopentadiene is 15wt%, the concentration of norbornene solution is 80wt%, and the solvent is toluene. The molar ratio of crude dicyclopentadiene to norbornene is 1:8, and the molar ratio of crude dicyclopentadiene to ethylene is 1:10. Crude dicyclopentadiene, norbornene, toluene and ethylene are mixed in a mixer, preheated to 160°C and then fed into a reactor. The reaction pressure is set to 3MPa, the temperature is 220°C, and the reaction residence time is 10min.

[0070] The comparative example adopts four-stage distillation, and the crude product is sent to the first distillation tower after the reaction. The top temperature of the first distillation tower is set at 40°C, the bottom temperature is set at 65°C, the top product returns to the reactor, and the bottom product is sent to the second distillation tower. The top temperature of the second distillation tower is set at 110°C, the bottom temperature is set at 130°C, the top product is returned for circulation, and the bottom product is sent to the third distillation tower. The top temperature of the third distillation tower is set at 140°C, the bottom temperature is set at 170°C, the top product is extracted, and the bottom product is sent to the fourth distillation tower. The fourth distillation tower is a vacuum distillation, the top pressure is set at 0.3kPa, the temperature is set at 120°C, the bottom pressure is set at 10kPa, the temperature is set at 95°C, the top of the tower produces tetracyclododecene, and the bottom of the tower obtains high boiling point by-products.

[0071] The results of gas chromatography analysis showed that the conversion rate of dicyclopentadiene was 87%, the purity of tetracyclododecene product was 99%, and the yield was 73%.

[0072] The results of all the above examples are shown in Table 1

[0073] Table 1 Reaction parameters and product properties of the embodiments and comparative examples

[0074]

[0075]

[0076] It can be seen from Table 1 that, when only the distillation method is changed, the yield of tetracyclododecene in Example 1 is only 1% lower than that in Comparative Example 1, but the equipment cost and energy consumption can be greatly saved.

[0077] The tetracyclododecene obtained by the method of the present invention has a high purity (≥99%), that is, the present invention uses crude dicyclopentadiene with an impurity content of ≤15% as a raw material and only needs to adopt a three-stage distillation preparation method to obtain a high-purity tetracyclododecene product. Compared with the prior art, the cost and energy consumption are greatly reduced, and the method has obvious technical advantages.

[0078] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A method for preparing tetracyclododecene, characterized in that: The following steps are involved: S1: Using crude dicyclopentadiene, norbornene solution and ethylene as raw materials, firstly sending dicyclopentadiene and norbornene solution to a mixer, then increasing the pressure of ethylene to the required pressure through a compressor and sending it to the mixer, and then preheating the raw materials in the mixer and sending them to a reactor for Diels-Alder reaction to obtain a crude tetracyclododecene product; wherein the impurity content of the crude dicyclopentadiene is ≤15%; S2: The crude tetracyclododecene product obtained in step S1 is subjected to three-stage distillation in a first distillation tower, a second distillation tower and a third distillation tower respectively to obtain a high-purity tetracyclododecene product.

2. A method for preparing tetracyclododecene according to claim 1, characterized in that: In step S1, the impurities contained in the crude dicyclopentadiene include one or more of methyldicyclopentadiene, isobutylene, p-methylstyrene or naphthalene.

3. A method for preparing tetracyclododecene according to claim 1, characterized in that: In step S1, the solvent of the norbornene solution is any combination of one or more of the aromatic solvents toluene, xylene or ethylbenzene, or the aliphatic solvents ethylcyclopentane or dimethylcyclopentane; and the mass concentration of norbornene in the norbornene solution is 10 to 90%.

4. The method for preparing tetracyclododecene according to claim 1, wherein: In step S1, the purity of the ethylene is ≥99%.

5. The method for preparing tetracyclododecene according to claim 1, wherein: In step S1, the molar ratio of the crude dicyclopentadiene to norbornene is 1:(1-15).

6. The method for preparing tetracyclododecene according to claim 1, characterized in that: In step S1, the molar ratio of crude dicyclopentadiene to ethylene is 1:(5-20).

7. The method for preparing tetracyclododecene according to claim 1, characterized in that: In step S1, the mixer has a rotating speed of 500 to 2200 r / min and a stirring time of 1 to 60 min.

8. The method for preparing tetracyclododecene according to claim 1, characterized in that: In step S1, the preheating temperature of the mixed preheating is 150-190°C.

9. The method for preparing tetracyclododecene according to claim 1, characterized in that: In step S1, the reaction temperature in the reactor is 220° C. to 260° C., the reaction pressure is 1.0 to 5.0 MPa, the reaction time is 0.1 to 3 h, and the crude tetracyclododecene product obtained after the reaction is sent to the first distillation tower.

10. The method for preparing tetracyclododecene according to claim 1, characterized in that: In step S2, the first stage of distillation is completed in the first distillation tower, the raw material is the crude tetracyclododecene product obtained in step S1, the distillation process is atmospheric distillation, the tower top temperature is set to 30-45°C, the tower bottom temperature is set to 60-80°C, the first tower bottom liquid is obtained, and it is sent to the second distillation tower, and at the same time, the unreacted ethylene is recovered and sent back to the ethylene feed pipeline.

11. The method for preparing tetracyclododecene according to claim 1, characterized in that: In step S2, the second stage of distillation is completed in the second distillation tower, the raw material is the first tower bottom liquid, the distillation process is atmospheric distillation, the tower top temperature is set to 90-140°C, the tower bottom temperature is set to 130-180°C, the second tower bottom liquid is obtained, and it is sent to the third distillation tower, and the unreacted dicyclopentadiene and norbornene solution are recovered and sent back to the feed pipeline of dicyclopentadiene and norbornene.

12. The method for preparing tetracyclododecene according to claim 1, characterized in that: In step S2, the third stage of distillation is completed in the third distillation tower, the raw material is the second tower bottom liquid, the distillation process is vacuum distillation, the tower top pressure is set to 0.2-0.6 kPa, the tower top temperature is set to 65-135 ° C, the tower bottom pressure is set to 1-15 kPa, the tower bottom temperature is set to 90-160 ° C, a high-purity tetracyclododecene product is obtained at the tower top, and a heavy oil by-product is obtained at the tower bottom.

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