Dispenser and method and system for synthesizing norbornene-based compounds

Abstract

This invention relates to the field of organic synthesis, specifically to a disperser and a method and system for synthesizing norbornene compounds. The present invention uses the disperser to disperse conjugated dienes or their precursors in a dienophile, and then carries out a Diels-Alder reaction in a Diels-Alder reactor preferably equipped with helical blades. This enhances mass transfer, improves norbornene selectivity, effectively increases norbornene yield, reduces the formation of heavy components, and improves production safety.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis, and more specifically, to a disperser, the application of the disperser in dispersing conjugated dienes and / or their precursors, a system for synthesizing norbornene compounds, the application of the disperser or the system in the synthesis of norbornene compounds, and a method for synthesizing norbornene compounds. Background Technology

[0002] Norbornene is an important comonomer that can be used with α-olefins such as ethylene, propylene, and styrene through non-ring-opening polymerization in the presence of Ziegler-Natta or metallocene catalysts to prepare cyclic olefin copolymers (COCs). COCs possess excellent heat resistance, chemical stability, extremely high transparency, dimensional stability, melt flowability, moisture barrier properties, and extremely low dielectric constant, and are widely used in the manufacture of contact lenses, automotive headlights, optical lenses, prisms, optical films for LCDs, food packaging, and electronic and electrical components. Norbornene is prepared by the Diels-Alder cycloaddition reaction of cyclopentadiene and ethylene under high temperature and pressure. This reaction releases a large amount of heat, which can easily cause localized overheating. Excessively high temperatures can cause the organic compounds to break down and decompose, producing small molecule compounds or even gases, leading to a sudden increase in system pressure and posing an explosion risk.

[0003] Cyclopentadiene is a cyclic conjugated diene with highly reactive chemical properties, making it a crucial chemical raw material with wide applications. Cyclopentadiene undergoes self-cyclization at room temperature to form dicyclopentadiene, which is then used in its current form. To obtain dicyclopentadiene, a depolymerization reaction is required. Dicyclopentadiene is primarily obtained through two routes: one is from the cracked C5 fraction produced in industrial ethylene production units using petroleum distillate thermal cracking, and the other is from the cracked C9 fraction in ethylene plants. These two sources differ in their impurity content, typically resulting in a purity of 80-85% for dicyclopentadiene. To obtain higher purity cyclopentadiene, thermal depolymerization is commonly used to depolymerize dicyclopentadiene into cyclopentadiene. This increases the relative volatility difference between cyclopentadiene and other components, allowing for the separation of high-purity cyclopentadiene through distillation. Dicyclopentadiene depolymerization methods are divided into liquid-phase depolymerization and gas-phase depolymerization. Current liquid-phase depolymerization refers to the thermal decomposition of dicyclopentadiene into cyclopentadiene in a liquid solvent (or high-temperature heat transfer oil). The depolymerization temperature is relatively mild, but the drawback is that the heavy components produced during depolymerization remain in the solvent, making solvent recovery difficult and generating organic waste liquid, posing environmental problems. Gas-phase depolymerization refers to the thermal decomposition of dicyclopentadiene in a gaseous state upon heating at a higher temperature.

[0004] The synthesis of norbornene can be divided into solvent-free and solvent-based processes. In the solvent-free process, the reactant concentration is relatively high, and cyclopentadiene undergoes cascade cycloaddition reactions with cyclopentadiene, dicyclopentadiene, norbornene, oligomers, etc., generating byproducts such as colloids with large molecular weights. To reduce the occurrence of side reactions, a solvent is introduced into the reaction system.

[0005] Among the publicly available technologies, some involve setting up a depolymerization vessel before the tubular reactor to retain the colloid within for easier cleaning. However, analysis has revealed a higher concentration of cyclopentadiene in the depolymerization vessel, increasing the likelihood of side reactions. Other technologies employ microchannel reactors, achieving higher conversion rates and selectivity; however, the smaller reactor size makes them more prone to clogging. All existing technologies have unsatisfactory aspects, preventing domestic industrialization of this technology and necessitating imports of norbornene products, leaving researchers in this vulnerable position. Overcoming these technological barriers is a pressing issue for researchers in this field. Summary of the Invention

[0006] The purpose of this invention is to provide an apparatus for the production of norbornene compounds that, while maintaining high conversion rates and selectivity, offers excellent dispersion and significantly reduces the formation of gum components. This apparatus provides a disperser capable of effectively dispersing conjugated dienes, enhancing mass transfer, improving the selectivity of norbornene compounds, reducing the formation of gum components, and ensuring high safety. This invention also provides the application of the disperser in dispersing conjugated dienes and / or their precursors, a system for synthesizing norbornene compounds, the application of the disperser or the system in the synthesis of norbornene compounds, and a method for synthesizing norbornene compounds.

[0007] To achieve the above objectives, the first aspect of the present invention provides a disperser, the disperser comprising a disperser housing, a material distributor and a plurality of dispersion tubes located inside the housing, and a front feed port and a side feed port located on the disperser housing.

[0008] The front feed inlet is located at the front end of the outer shell, and the material distributor and multiple dispersion tubes are located in front of the disperser. The material distributor has holes distributed on it, and each hole is connected to each dispersion tube, so that the first material enters the disperser through the front feed inlet, is dispersed by the material distributor, and then enters the multiple dispersion tubes.

[0009] The plurality of dispersion tubes extend toward the rear end of the disperser along the axial direction of the outer shell, but do not contact it;

[0010] The side feed inlet is located on the outer casing between the material distributor and the dispersion tube outlet.

[0011] A second aspect of the invention provides the use of the disperser described above in dispersing conjugated dienes and / or their precursors.

[0012] Preferably, the first material comprises a conjugated diene and / or its precursor, and optionally an inert solvent.

[0013] Preferably, the second material entering through the side feed port is different from the first material, and the second material is a dienophile and / or an inert solvent.

[0014] A third aspect of the present invention provides a system for synthesizing norbornene compounds, the system comprising a disperser and a Diels-Alder reactor connected in sequence as described above, for allowing a material mixed in the disperser, containing a conjugated diene and / or its precursor, a dienophile, and optionally an inert solvent, to enter the Diels-Alder reactor for a Diels-Alder reaction.

[0015] The fourth aspect of the present invention provides the use of the disperser or system described above in the synthesis of norbornene compounds.

[0016] The fifth aspect of the present invention provides a method for synthesizing norbornene compounds, the method comprising: mixing a conjugated diene and / or its precursor with a dienophile in a disperser as described above to obtain a mixed material; and then subjecting the mixed material to a Diels-Alder reaction to obtain a norbornene compound;

[0017] The first material contains a conjugated diene and / or its precursor; the second material entering the disperser via the side feed inlet contains a dienophile.

[0018] Preferably, the Diels-Alder reaction is carried out in a Diels-Alder reactor equipped with helical blades.

[0019] Preferably, the temperature of the first material is 50-120℃ and the pressure is 5-20MPa.

[0020] Preferably, the temperature of the second material is 200-320℃ and the pressure is 5-20MPa.

[0021] Conjugated dienes and their precursors are highly reactive and prone to polymerization, generating colloids that can cause reactor blockage, reduced product yield, and increased byproducts. This is particularly problematic when conjugated dienes used to synthesize norbornene compounds undergo a Diels-Alder cycloaddition reaction with a dienophile under high temperature and pressure. This reaction releases a large amount of heat, and poor dispersion can easily lead to localized overheating and explosion risks. In this invention, a fine-bundle disperser with a specific structure disperses the conjugated dienes or their precursors in an environment of a dienophile or inert solvent before transporting them to the reactor for reaction. This enhances mass transfer and achieves uniform dispersion, effectively improving the selectivity of norbornene compounds, reducing the formation of heavy components, minimizing explosion risks, and improving production safety.

[0022] In the production of norbornene compounds, controlling the temperature and pressure of the first and second materials within preferred ranges, and using a reactor preferably equipped with helical blades for the reaction, can further reduce the generation of by-products and heavy components, and improve the selectivity of norbornene compounds. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the disperser described in an embodiment of the present invention.

[0024] Explanation of reference numerals in the attached figures

[0025] 1. Top feed inlet; 2. Disperser shell; 3. Material distributor; 4. Dispersion tube; 5. Side feed inlet. Detailed Implementation

[0026] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0027] To achieve the above objectives, the first aspect of the present invention provides a disperser, the disperser comprising a disperser housing, a material distributor and a plurality of dispersion tubes located inside the housing, and a front feed port and a side feed port located on the disperser housing.

[0028] The front feed inlet is located at the front end of the outer shell, and the material distributor and multiple dispersion tubes are located in front of the disperser. The material distributor has holes distributed on it, and each hole is connected to each dispersion tube, so that the first material enters the disperser through the front feed inlet, is dispersed by the material distributor, and then enters the multiple dispersion tubes.

[0029] The plurality of dispersion tubes extend toward the rear end of the disperser along the axial direction of the outer shell, but do not contact it;

[0030] The side feed inlet is located on the outer casing between the material distributor and the dispersion tube outlet.

[0031] The appearance of the disperser is not particularly limited; for example, it can be tubular. The aspect ratio of the disperser is also not particularly limited; for example, it can be 2-10:1, such as 2:1, 4:1, 6:1, 8:1, 10:1, or any range between any two values. It should be understood that factors such as economy and ease of operation are considered during disperser design, and those skilled in the art can make adaptive adjustments as needed. In addition to the inlet and outlet ports, the disperser shell can also be equipped with conventional auxiliary devices, such as temperature or pressure control devices.

[0032] Preferably, the density of holes on the material distributor is 1-4 holes / cm². 2 For example, it can be 1, 2, 3, or 4 per cm. 2 It should be understood that the holes on the material distributor are distributed as evenly as possible.

[0033] Preferably, the diameter of the hole is 0.5-2.5 mm, for example, it can be 0.5, 0.8, 1, 1.2, 1.5, 2, 2.5 mm, or any range between any two values.

[0034] Preferably, the material distributor is a detachable distributor. To make the material distributor detachable, the front end of the disperser can be configured as a flange or threaded end cap, with the front feed port provided on it. A buffer space can exist between the front feed port and the material distributor, serving as a feed chamber. The diameter of the material distributor is the same as the inner diameter of the disperser, so that the first material is dispersed entirely from the material distributor.

[0035] Preferably, the material distributor is placed perpendicular to the axis of the disperser.

[0036] The number and inner diameter of the dispersion tubes can correspond to the number and inner diameter of the holes on the material distributor. There is no particular limitation on their length, as long as the space at the end of the dispersion tube can allow the material to be fully dispersed. Preferably, the length of the dispersion tube is 80-95% of the length of the disperser, such as 80%, 85%, 90%, 95%, or any range between any two values.

[0037] Preferably, the side feed inlet is located on the disperser housing at a position corresponding to the first 5-60% of the dispersion tube (for example, it can be 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60% and any range between any two values).

[0038] There is no particular limitation on the number of side feed inlets. To ensure more uniform material dispersion, it is preferable that there are 2-10 side feed inlets, such as 2, 3, 4, 5, 6, 7, 8, 9, or 10. Preferably, the side feed inlets are evenly or symmetrically distributed along the radial interface of the outer shell. The types of materials fed through the side feed inlets can be the same or different.

[0039] In this invention, the area including the front feed port, the side feed port, the material distributor and the dispersion tube is the feeding area, and the area behind the dispersion tube is the mixing area.

[0040] When the disperser is used as a standalone device, it may also include a discharge port, and the area from the rear of the dispersion tube to the discharge port is a mixing zone, where a reaction may also occur.

[0041] When the disperser is part of a Diels-Alder reactor, it is located at the front end of the reactor, and the mixed materials enter the reaction zone. The reaction zone can be equipped with internal components to improve material mixing, such as twisted blades or helical blades, preferably helical blades. Those skilled in the art can install the internal components according to their type and structure. For example, the helical blades can be welded to the reactor, with their central axis coinciding with the reactor's central axis. The helical blades have a sheet-like structure, with different radial cross-sections spiraling sequentially along the same circumferential direction along the reactor's axial direction, changing the fluid flow state near the reactor wall and reducing the adhesion of colloids to the wall. When the helical blades are short, they can be called helical twisted blades, and multiple helical twisted blades can be used to achieve the desired mixing effect. The Diels-Alder reactor can be tubular. Preferably, the radial width of the helical blade is 0.35-1 times the inner diameter of the reactor (e.g., it can be 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.8, 0.9, 1 times, or any range between any two values), more preferably 0.35-0.7 times; the length of one revolution of the helix (also called the helix pitch) is 2-5 times the inner diameter of the reactor (e.g., it can be 2, 2.5, 3, 3.5, 4, 4.5, 5 times, or any range between any two values), more preferably 2-4 times; and the distance between the outer edge of the helical blade and the inner wall of the reactor (i.e., half the difference between the inner diameter of the reactor and the outer diameter of the helical blade) is 0-0.2 times the inner diameter of the reactor (e.g., it can be 0, 0.05, 0.1, 0.15, 0.2 times, or any range between any two values), more preferably 0-0.1 times.

[0042] A second aspect of the invention provides the use of the disperser described above in dispersing conjugated dienes and / or their precursors.

[0043] The conjugated diene can be a conventional conjugated diene in the art, such as cyclopentadiene and cis-1,3-butadiene, etc. The precursor refers to the substance in the previous step before obtaining the conjugated diene, for example, the precursor of cyclopentadiene is dicyclopentadiene.

[0044] Preferably, the first material comprises a conjugated diene and / or its precursor, and optionally an inert solvent. It should be understood that the first material may be a feedstock containing a conjugated diene and / or its precursor, which may contain impurities. For example, the dicyclopentadiene feedstock may be separated from cracked C5 fractions produced in an industrial unit for the thermal cracking of petroleum fractions to produce ethylene. Preferably, the content of the conjugated diene and / or its precursor in the feedstock is 70 wt% or more, for example, it may be 70, 75, 80, 85, 90, 95 wt% or more, or any range between any two values.

[0045] Preferably, the conjugated diene and / or its precursor is selected from one of dicyclopentadiene, cyclopentadiene, and cis-1,3-butadiene.

[0046] Preferably, the inert solvent is selected from at least one of benzene, toluene, cyclohexane, xylene, n-pentane, cyclopentane, hexane, heptane, and octane.

[0047] Preferably, the second material entering through the side feed port is different from the first material, and the second material is a dienophile and / or an inert solvent.

[0048] In this invention, the dienophile is a substance capable of undergoing a Diels-Alder reaction with the conjugated diene. Preferably, the dienophile is selected from at least one of ethylene, acetylene, and cis-1,3-butadiene.

[0049] Preferably, the molar ratio of the conjugated diene and / or its precursor to the dienophile is 1:3-60, for example, it can be 1:3, 1:5, 1:10, 1:15, 1:20, 1:25, 1:30, 1:35, 1:40, 1:45, 1:50, 1:55, 1:60, or any range of any two values, more preferably 1:8-40.

[0050] There is no particular limitation on the amount of the inert solvent. Preferably, the inert solvent accounts for 1-99% of the volume of the mixture of the first material and the second material, for example, it can be 1, 10, 20, 30, 40, 50, 60, 70, 80, 90, 99% by volume and any range between any two values.

[0051] Preferably, the temperature of the first material is 50-120℃ and the pressure is 5-20MPa.

[0052] Preferably, the temperature of the second material is 200-320℃ and the pressure is 5-20MPa.

[0053] Preferably, the pressures of the first material and the second material are the same.

[0054] A third aspect of the present invention provides a system for synthesizing norbornene compounds, the system comprising a disperser and a Diels-Alder reactor connected in sequence as described above, for allowing a material mixed in the disperser, containing a conjugated diene and / or its precursor, a dienophile, and optionally an inert solvent, to enter the Diels-Alder reactor for a Diels-Alder reaction.

[0055] In this invention, preferably, the norbornene compound is norbornene, 2,5-norbornediene, or ethylidene norbornene.

[0056] The disperser and the Diels-Alder reactor can be two separate devices, or they can be located in the same device (Diels-Alder reactor).

[0057] Preferably, the front feed port is used for feeding conjugated dienes and / or their precursors and optionally an inert solvent, and the side feed port is used for feeding dienophiles and optionally an inert solvent.

[0058] Preferably, the Diels-Alder reactor is provided with helical blades. A description of the helical blades is given in the first aspect and will not be repeated here.

[0059] In a preferred embodiment of the present invention, the disperser and the Diels-Alder reactor are placed vertically along the axis, with the disperser located above the Diels-Alder reactor. The Diels-Alder reactor may or may not have helical blades. Preferably, the Diels-Alder reactor has helical blades.

[0060] In a preferred embodiment of the invention, the disperser and the Diels-Alder reactor are placed horizontally along the axis, and the Diels-Alder reactor is provided with helical blades.

[0061] Preferably, the system further includes a dienophile recovery tower connected to the Diels-Alder reactor via a pipeline for recovering diens from the material after the Diels-Alder reaction from the top of the tower.

[0062] Preferably, a cooling device is also provided between the ethylene recovery tower and the Diels-Alder reactor for cooling the material after the Diels-Alder reaction.

[0063] Preferably, the system further includes a tetracyclic dodecene de-column tower, which is connected to a dienophile recovery tower via a pipeline for separating the bottom material from the dienophile recovery tower, and extracting the material containing tetracyclic dodecene from the top of the tower and the material containing norbornene compounds from the bottom of the tower.

[0064] Preferably, the tetracyclic dodecene detetracyclic column is also connected to the Diels-Alder reactor via a pipeline for recycling the tetracyclic dodecene-containing material to the Diels-Alder reactor to produce norbornene compounds.

[0065] Preferably, the system further includes a norbornene tower, which is connected to detetracyclic dodecene via a pipeline for refining materials containing norbornene compounds to obtain norbornene compounds.

[0066] The fourth aspect of the present invention provides the use of the disperser or system described above in the synthesis of norbornene compounds.

[0067] Preferably, the first material comprises a conjugated diene and / or its precursor, and optionally an inert solvent; more preferably, the conjugated diene and / or its precursor is dicyclopentadiene and / or cyclopentadiene.

[0068] For information on norbornene compounds, the second material, the dienophile, and the inert solvent, please refer to sections two and three. For information on reaction conditions and control, please refer to section five. These will not be repeated here.

[0069] The fifth aspect of the present invention provides a method for synthesizing norbornene compounds, the method comprising: mixing a conjugated diene and / or its precursor with a dienophile in a disperser as described above to obtain a mixed material; and then subjecting the mixed material to a Diels-Alder reaction to obtain a norbornene compound;

[0070] The first material comprises a conjugated diene and / or its precursor; the second material, which enters the disperser via a side inlet, comprises a dienophile. Optionally, both the first and second materials also contain an inert solvent.

[0071] Preferably, the temperature of the first material is 50-120℃, for example, it can be any range of 50, 60, 80, 100, 120℃ or any two of these values, and the pressure is 5-20 MPa, for example, it can be any range of 5, 6, 8, 10, 12, 14, 16, 18, 20 MPa or any two of these values.

[0072] Preferably, the temperature of the second material is 200-320℃, for example, it can be any range of 200, 220, 240, 260, 280, 300, 320℃ and any two of these values, and the pressure is 5-20MPa, for example, it can be any range of 5, 6, 8, 10, 12, 14, 16, 18, 20MPa and any two of these values.

[0073] Preferably, the flow rate ratio of the first material and the second material is controlled such that the temperature of the mixed material reaches the Diels-Alder reaction temperature. Preferably, the molar ratio of the conjugated diene and / or its precursor to the dienophile is 1:3-60, for example, it can be 1:2, 1:5, 1:10, 1:15, 1:20, 1:25, 1:30, or any range between any two values, more preferably 1:8-22. The temperature can be reached by adjusting the amount of inert solvent.

[0074] Preferably, the conditions for the Diels-Alder reaction include: a temperature of 180-310°C, for example, any range consisting of 180, 200, 220, 240, 260, 280, 300, 3 / 10°C, or any two of these values, more preferably 240-290°C; and a pressure of 5-20 MPa, for example, any range consisting of 5, 6, 8, 10, 12, 14, 16, 18, 20 MPa, or any two of these values, more preferably 10-16 MPa.

[0075] The residence time and feed rate of the reactants in the reactor can be selected within a wide range, as long as optimal selectivity is achieved. Preferably, the residence time is 5-120 min, more preferably 10-60 min.

[0076] Preferably, the Diels-Alder reaction is carried out in a Diels-Alder reactor equipped with helical blades. A description of the helical blades is given in the first aspect and will not be repeated here.

[0077] The relative positions of the disperser and the Diels-Alder reactor are described in the fourth aspect and will not be repeated here.

[0078] Those skilled in the art can select the appropriate device size based on the production scale, which will not be elaborated here.

[0079] Preferably, the method further includes: refining the material after the Diels-Alder reaction to obtain norbornene.

[0080] Preferably, the material after the Diels-Alder reaction is cooled to 40-80°C and then purified.

[0081] Preferably, the purification method includes sequentially separating ethylene and cyclopentadiene and tetracyclododecene from the materials after the Diels-Alder reaction. Those skilled in the art can select appropriate operating conditions based on the types of reactants.

[0082] Preferably, the method further includes recycling the material containing cyclopentadiene and tetracyclododecene to the Diels-Alder reactor for the production of norbornene.

[0083] The present invention will be described in detail below through embodiments.

[0084] Unless otherwise specified, the operating conditions in the following examples and comparative examples are all at atmospheric pressure.

[0085] Example 1

[0086] This embodiment illustrates the system and method for synthesizing norbornene.

[0087] (1) System for synthesizing norbornene

[0088] The system includes sequentially connected components such as... Figure 1 The disperser and tubular reactor shown are arranged vertically along the axis, with the disperser located above the Diels-Alder reactor, which is equipped with helical blades.

[0089] like Figure 1 As shown, the disperser includes a disperser housing 2, a material distributor 3 and multiple dispersion tubes 4 located inside the disperser housing 2, and a front feed inlet 1 and a side feed inlet 5 located on the disperser housing 2; wherein, the front feed inlet 1 is located at the front end of the disperser housing 2, the material distributor 3 and multiple dispersion tubes 4 are located at the front side of the disperser, the material distributor 3 has holes distributed on it, and each hole is connected to each dispersion tube 4, so that the first material enters the disperser through the front feed inlet 1, is dispersed by the material distributor 3, and then enters the multiple dispersion tubes 4; the multiple dispersion tubes 4 extend towards the rear end of the disperser along the axial direction of the disperser housing 2, but do not contact it; the side feed inlet 5 is provided on the disperser housing 2 between the material distributor 3 and the outlet of the dispersion tube 4.

[0090] The disperser has an inner diameter of 32mm, and the material distributor has 16 holes with an inner diameter of 1mm, corresponding to 16 dispersing tubes with an inner diameter of 1mm. The length of each dispersing tube is 200mm, and the distance from the end of the dispersing tube to the outlet of the disperser is 10mm. Two side feed ports are symmetrically distributed on the outer shell 120mm above the end of the dispersing tube and connected to the same feed line.

[0091] The radial width of the helical blade is 15 mm, the length of one helix is ​​90 mm, and the distance between the outer edge of the helical blade and the inner wall of the reactor is 1 mm.

[0092] (2) Methods for synthesizing norbornene

[0093] A mixture of dicyclopentadiene and toluene (50 wt% dicyclopentadiene concentration, 100°C, 16 MPa pressure) was fed into the disperser through the front inlet, while ethylene (280°C, 16 MPa pressure) was fed into the disperser through the side inlet. The molar ratio of dicyclopentadiene to ethylene was 1:10. The mixture was then fed into a Diels-Alder reactor for the Diels-Alder reaction at 260°C and 16 MPa. The feed rate and residence time were controlled to ensure 100% conversion of dicyclopentadiene.

[0094] At this point, the selectivity for synthesizing norbornene was 97%, and the selectivity for tetracyclododecene (DMON) was 2.5%. After 100 hours of continuous operation, 0.5 grams of solid were scraped out of the reactor after the experiment was stopped, and there was no obvious scale buildup in the disperser.

[0095] Example 2

[0096] (1) System for synthesizing norbornene

[0097] The system is as shown in Example 1, except that the material distributor has 24 holes with an inner diameter of 1 mm, corresponding to 24 dispersion tubes with an inner diameter of 1 mm. The length of the dispersion tube is 150 mm, and the distance from the end of the dispersion tube to the reactor outlet is 5 mm. Four side feed ports are symmetrically distributed on the outer shell 135 mm above the end of the dispersion tube and connected to the same feed line.

[0098] The radial width of the helical blade is 13mm, the length of one helix is ​​150mm, and the distance between the outer edge of the helical blade and the inner wall of the reactor is 2mm.

[0099] (2) Methods for synthesizing norbornene

[0100] A mixture of dicyclopentadiene and toluene (50 wt% dicyclopentadiene concentration, 120°C, 18 MPa pressure) is fed into the disperser through the front inlet, while ethylene (270°C, 18 MPa pressure) is fed into the disperser through the side inlet. The molar ratio of dicyclopentadiene to ethylene is 1:15. The mixed materials then enter a Diels-Alder reactor for the Diels-Alder reaction at 240°C and 18 MPa.

[0101] The feed rate and residence time were adjusted to achieve a 100% conversion rate of dicyclopentadiene. At this point, the selectivity for synthesizing norbornene was 98%, and the selectivity for tetracyclododecene (DMON) was 1.2%. After continuous operation for 100 hours, 0.2 grams of solid were scraped out of the reactor after the test was stopped, and there was no obvious scale buildup in the disperser.

[0102] Example 3

[0103] (1) System for synthesizing norbornene

[0104] The system is as shown in Example 1, except that the material distributor has 30 holes with an inner diameter of 2 mm, corresponding to 30 dispersion tubes with an inner diameter of 2 mm. The length of the dispersion tubes is 220 mm, and the distance from the end of the dispersion tube to the reactor outlet is 30 mm. Eight side feed ports are symmetrically distributed on the outer shell 176 mm above the end of the dispersion tubes and connected to the same feed line.

[0105] The radial width of the helical blade is 30 mm, the length of one helix is ​​70 mm, and the distance between the outer edge of the helical blade and the inner wall of the reactor is 1 mm.

[0106] (2) Methods for synthesizing norbornene

[0107] A mixture of dicyclopentadiene and toluene (50 wt% dicyclopentadiene concentration, 60°C, 14 MPa pressure) is fed into the disperser through the front inlet, while ethylene (320°C, 14 MPa pressure) is fed into the disperser through the side inlet. The molar ratio of dicyclopentadiene to ethylene is 1:8. The mixed materials then enter a Diels-Alder reactor for the Diels-Alder reaction at 210°C and 14 MPa.

[0108] The feed rate and residence time were adjusted to achieve a 100% conversion rate of dicyclopentadiene. At this point, the selectivity for synthesizing norbornene was 95%, and the selectivity for tetracyclododecene (DMON) was 3.1%. After 100 hours of continuous operation, 1.3 grams of solid were scraped out of the reactor after the experiment was stopped, and there was no obvious scale buildup in the disperser.

[0109] Example 4

[0110] The system described in Example 1 was operated according to the method described in Example 1, except that 98 wt% dicyclopentadiene was used instead of the mixture of dicyclopentadiene and toluene, the molar ratio of ethylene to dicyclopentadiene was 15:1, the temperature of the reaction section of the tubular reactor was 250°C, and the reaction pressure was 15 MPa. The feed rate and residence time were adjusted to achieve a 100% conversion rate of dicyclopentadiene. At this point, the selectivity for synthesizing norbornene was 94.5%, and the selectivity for tetracyclododecene (DMON) was 4.1%. After continuous operation for 100 hours, 2.1 grams of solid were scraped from the tubular reactor after the experiment was stopped.

[0111] Example 5

[0112] The system described in Example 1 is operated according to the method described in Example 1, except that the Diels-Alder reactor does not have helical blades.

[0113] The feed rate and residence time were adjusted to achieve a 100% conversion rate of dicyclopentadiene. At this point, the selectivity for synthesizing norbornene was 95.6%, and the selectivity for tetracyclododecene (DMON) was 3.5%. After 100 hours of continuous operation, 1.9 grams of solid were scraped out of the reactor after the experiment was stopped, and there was no obvious scale buildup in the disperser.

[0114] Example 6

[0115] The system described in Example 1 is operated according to the method described in Example 1, except that instead of using helical blades, several twisted blades are used instead. The width of the twisted blades is equal to the inner diameter of the tubular reactor, the spiral is 90°, and the length is twice the inner diameter. Four twisted blades are evenly spaced inside the tubular reactor.

[0116] The feed rate and residence time were adjusted to achieve a 100% conversion rate of dicyclopentadiene. At this point, the selectivity for synthesizing norbornene was 96.2%, and the selectivity for tetracyclododecene (DMON) was 2.3%. After 100 hours of continuous operation, 1.2 grams of solid were scraped out of the reactor after the experiment was stopped, and there was no obvious scale buildup in the disperser.

[0117] Example 7

[0118] The system described in Example 1 is operated in accordance with the method described in Example 1, except that both the disperser and the Diels-Alder reactor are placed horizontally along the axis.

[0119] The feed rate and residence time were adjusted to achieve a 100% conversion rate of dicyclopentadiene. At this point, the selectivity for synthesizing norbornene was 96.5%, and the selectivity for tetracyclododecene (DMON) was 2.2%. After continuous operation for 100 hours, 0.7 grams of solid were scraped out of the reactor after the experiment was stopped, and there was no obvious scale buildup in the disperser.

[0120] Example 8

[0121] The system described in Example 1 is operated in accordance with the method described in Example 1, except that an equimolar amount of 1,3-butadiene is used instead of ethylene to produce vinylnorbornene.

[0122] The feed rate and residence time were adjusted to achieve a 100% conversion rate of dicyclopentadiene. At this point, the selectivity for synthesizing vinyl norbornene was 95%, and the selectivity for vinyl tetracyclododecene was 3%. After continuous operation for 100 hours, 1.8 grams of solid were scraped out of the reactor after the test was stopped, and there was no obvious scale buildup in the disperser.

[0123] Comparative Example 1

[0124] Unlike Example 1, only the Diels-Alder reactor was used.

[0125] A mixture of dicyclopentadiene and toluene was used as the raw material, with a dicyclopentadiene mass percentage concentration of 50% and a molar ratio of ethylene to dicyclopentadiene of 20:1. The reactor temperature was 240℃, and the reaction pressure was 14MPa. The feed rate was adjusted to achieve a dicyclopentadiene conversion of 100%. At this point, the selectivity for synthesizing norbornene was 93%, and the selectivity for tetracyclododecene (DMON) was 5.2%. After continuous operation for 100 hours, 4.5 grams of solid were scraped from the tubular reactor after the experiment was stopped.

[0126] Comparative Example 2

[0127] Unlike Example 1, a microchannel reactor was used instead of the system, while the raw materials, feed ratios, and reaction conditions were exactly the same as in Example 1.

[0128] The feed rate and residence time were adjusted to achieve a 100% conversion rate of dicyclopentadiene. At this point, the selectivity for synthesizing norbornene was 99%, and the selectivity for tetracyclododecene (DMON) was 0.6%. After 52 hours of continuous operation, the pressure difference between the reactor outlet and inlet gradually increased, and the reactor became completely blocked after 55 hours.

[0129] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for synthesizing norbornene compounds, characterized in that, The method includes: mixing a first material and a second material in a disperser to obtain a mixed material; and then subjecting the mixed material to a Diels-Alder reaction to obtain norbornene compounds. The disperser includes a disperser shell, a material distributor and multiple dispersion tubes located inside the shell, and a front feed inlet and a side feed inlet on the disperser shell. The front feed inlet is located at the front end of the shell, and the material distributor and multiple dispersion tubes are located at the front of the disperser. The material distributor has holes, each hole communicating with a dispersion tube, so that the first material enters the disperser through the front feed inlet, is dispersed by the material distributor, and then enters the multiple dispersion tubes. The multiple dispersion tubes extend along the axial direction of the shell towards the rear end of the disperser without contacting it. The side feed inlet is located on the shell between the material distributor and the dispersion tube outlets. The Diels-Alder reaction is carried out in a Diels-Alder reactor equipped with helical blades; The first material contains a conjugated diene and / or its precursor, as well as an inert solvent; the second material entering the disperser via a side feed inlet contains a dienophile. The conjugated diene and / or its precursor is selected from one of dicyclopentadiene, cyclopentadiene, and cis-1,3-butadiene; and / or The dienophile is selected from at least one of ethylene, acetylene, and cis-1,3-butadiene; The temperature of the first material is 50-120℃, and the pressure is 5-20MPa; The temperature of the second material is 200-320℃, and the pressure is 5-20MPa; The flow rate ratio of the first material and the second material is controlled so that the temperature of the mixed material reaches the Diels-Alder reaction temperature.

2. The method according to claim 1, characterized in that, The density of the holes on the material distributor is 1-4 holes / cm³. 2 The diameter of the hole is 0.5-2.5 mm.

3. The method according to claim 2, characterized in that, The material distributor is a detachable distributor.

4. The method according to claim 3, characterized in that, The material distributor is placed perpendicular to the axis of the disperser.

5. The method according to any one of claims 1-4, characterized in that, The side feed inlet is located on the disperser housing at the position corresponding to the first 5-60% of the dispersion tube.

6. The method according to claim 5, characterized in that, The number of side feed ports is 2-10.

7. The method according to any one of claims 1-4 and 6, characterized in that, The inert solvent is selected from at least one of benzene, toluene, cyclohexane, xylene, n-pentane, cyclopentane, hexane, heptane, and octane.

8. The method according to claim 5, characterized in that, The inert solvent is selected from at least one of benzene, toluene, cyclohexane, xylene, n-pentane, cyclopentane, hexane, heptane, and octane.

9. The method according to any one of claims 1-4, 6 and 8, wherein, The conditions for the Diels-Alder reaction include: a temperature of 180-310℃ and a pressure of 5-20MPa.

10. The method according to claim 5, wherein, The conditions for the Diels-Alder reaction include: a temperature of 180-310℃ and a pressure of 5-20MPa.

11. The method according to claim 7, wherein, The conditions for the Diels-Alder reaction include: a temperature of 180-310℃ and a pressure of 5-20MPa.

12. The method according to claim 9, wherein, The conditions for the Diels-Alder reaction include: a temperature of 240-290℃ and a pressure of 10-18 MPa.

13. The method according to claim 10, wherein, The conditions for the Diels-Alder reaction include: a temperature of 240-290℃ and a pressure of 10-18 MPa.

14. The method according to claim 11, wherein, The conditions for the Diels-Alder reaction include: a temperature of 240-290℃ and a pressure of 10-18 MPa.

15. The method according to claim 12, characterized in that, The radial width of the helical blades is 0.35-1 times the inner diameter of the reactor, and the length of one revolution of the helix is ​​2-5 times the inner diameter of the reactor.

16. The method according to claim 13, characterized in that, The radial width of the helical blades is 0.35-1 times the inner diameter of the reactor, and the length of one revolution of the helix is ​​2-5 times the inner diameter of the reactor.

17. The method according to claim 14, characterized in that, The radial width of the helical blades is 0.35-1 times the inner diameter of the reactor, and the length of one revolution of the helix is ​​2-5 times the inner diameter of the reactor.

18. The method according to any one of claims 1-4, 6, 8 and 10-17, wherein, The disperser and the Diels-Alder reactor are placed vertically along their axes, with the disperser positioned above the Diels-Alder reactor; or The disperser and Diels-Alder reactor are placed horizontally along the axis.

19. The method according to claim 5, wherein, The disperser and the Diels-Alder reactor are placed vertically along their axes, with the disperser positioned above the Diels-Alder reactor; or The disperser and Diels-Alder reactor are placed horizontally along the axis.

20. The method according to claim 7, wherein, The disperser and the Diels-Alder reactor are placed vertically along their axes, with the disperser positioned above the Diels-Alder reactor; or The disperser and Diels-Alder reactor are placed horizontally along the axis.

21. The method according to claim 9, wherein, The disperser and the Diels-Alder reactor are placed vertically along their axes, with the disperser positioned above the Diels-Alder reactor; or The disperser and Diels-Alder reactor are placed horizontally along the axis.

22. The method according to any one of claims 1-4, 6, 8, 10-17, and 19-21, wherein, The method also includes: refining the material after the Diels-Alder reaction to obtain norbornene.

23. The method according to claim 5, wherein, The method also includes: refining the material after the Diels-Alder reaction to obtain norbornene.

24. The method according to claim 7, wherein, The method also includes: refining the material after the Diels-Alder reaction to obtain norbornene.

25. The method according to claim 9, wherein, The method also includes: refining the material after the Diels-Alder reaction to obtain norbornene.

26. The method according to claim 18, wherein, The method also includes: refining the material after the Diels-Alder reaction to obtain norbornene.

27. The method according to claim 22, wherein, The purification method includes sequentially separating ethylene from the material after the Diels-Alder reaction, as well as separating cyclopentadiene and tetracyclododecene.

28. The method according to any one of claims 23-26, wherein, The purification method includes sequentially separating ethylene from the material after the Diels-Alder reaction, as well as separating cyclopentadiene and tetracyclododecene.

29. The method according to claim 27, wherein, The material after the Diels-Alder reaction is cooled to 40-80℃ and then purified.

30. The method according to claim 28, wherein, The material after the Diels-Alder reaction is cooled to 40-80℃ and then purified.

31. The method according to claim 27, wherein, The method also includes recycling materials containing cyclopentadiene and tetracyclododecene to the Diels-Alder reactor for the production of norbornene.

32. The method according to claim 28, wherein, The method also includes recycling materials containing cyclopentadiene and tetracyclododecene to the Diels-Alder reactor for the production of norbornene.

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