Norbornene reaction systems and methods

Abstract

The application discloses a norbornene reaction system and method. The norbornene reaction system comprises at least two reaction devices connected in series, wherein each reaction device is provided with a circulating loop leading out from a first gas outlet at the top, communicating with a gas inlet of a fluid mixing conveying device, and then communicating with the upper part of the reaction device; each reaction device is also provided with a circulating loop leading out from a liquid discharge port at the bottom, communicating with a heat exchange device and a liquid inlet of the fluid mixing conveying device in sequence, and then communicating with the upper part of the reaction device. The norbornene reaction system of the application has high reaction safety, and has better raw material conversion rate and product selectivity in the reaction process of synthesizing norbornene by arranging at least two reaction devices connected in series and containing an external circulating loop.

Description

TECHNICAL FIELD

[0001] The present application relates to a norbornene reaction system and method. BACKGROUND

[0002] Norbornene is a key monomer for the copolymerization with α-olefins to prepare cycloolefin copolymers (COCs) and is also a main precursor for the preparation of cycloolefin polymer (COP) monomers. Cycloolefin copolymers and cycloolefin polymers have excellent properties such as low density, low moisture absorption, high light transmittance, high refractive index, etc. and are special amorphous thermoplastic polymer materials with very high application value in the fields of optics, medical packaging materials, electronics, etc. Therefore, how to efficiently, stably and safely produce norbornene monomers has become the key to the preparation of downstream cycloolefin polymers.

[0003] At present, norbornene is mainly prepared from ethylene and cyclopentadiene or cyclopentadiene produced by the decomposition of dicyclopentadiene in the reaction system. The thermal decomposition reaction of dicyclopentadiene has a reaction temperature above 180℃, a relatively slow reaction rate, and the rate gradually increases with the increase of the reaction temperature; the reaction of ethylene and cyclopentadiene is a strong exothermic reaction with an exothermic amount of 22 kcal / mol. The synthesis method of norbornene from dicyclopentadiene or cyclopentadiene is actually very difficult to realize in industry because the reaction activity of ethylene is low and harsh operating conditions are required, which are very close to the explosion thermal decomposition conditions of dicyclopentadiene / cyclopentadiene. Using the traditional process to synthesize norbornene on a large scale (such as 2000 t / a single device), it is relatively easy to have a sharp temperature rise and pressure rise, which may eventually lead to a loss of control of the reaction, cause safety accidents, and the selectivity of the obtained product is low, increasing the cost of subsequent separation. This is also the reason why several industrial devices that attempt to synthesize norbornene have been forced to shut down due to explosions.

[0004] Patent CN105481625A discloses a production method of norbornene, which discloses the use of two serially connected tank reactors to make dicyclopentadiene depolymerize into cyclopentadiene at relatively low temperature and pressure, and the double olefin synthesis reaction of cyclopentadiene and ethylene to convert into norbornene. The defect of this patent is that if the reaction temperature is relatively high and a relatively serious exothermic effect occurs during the reaction, there is a great risk of safety due to the lack of heat removal means, and the selectivity of dicyclopentadiene is relatively low. SUMMARY

[0005] The present application aims to overcome the shortcomings of poor safety, low conversion rate and selectivity, and many by-products in the prior art, and provides a norbornene reaction system and method.

[0006] The present application provides a norbornene reaction system, which comprises at least two reaction devices connected in series,

[0007] Each reaction device is provided with a circulation loop leading from a first gas outlet at the top, communicating with a gas inlet of a fluid mixing and conveying device, and further communicating with the upper part of the reaction device.

[0008] Each reaction device is further provided with a circulation loop leading from a liquid discharge port at the bottom, sequentially communicating with a heat exchange device, a liquid inlet of the fluid mixing and conveying device, and further communicating with the upper part of the reaction device.

[0009] In the present application, the gas from the first gas outlet and the liquid from the bottom liquid discharge port after heat exchange in the heat exchange device are mixed in the fluid mixing and conveying device, which can enhance the solubility of the reaction raw material such as ethylene gas in the solution and promote the forward reaction in the reaction device.

[0010] In the present application, preferably, the lower part of the reaction device is further provided with a gas dispersion device connected with the gas inlet port at the bottom of the reaction device.

[0011] In the present application, the gas inlet port and the gas dispersion device are arranged in the lower part of the reaction device, which is beneficial to expand the dispersion of the gas raw material such as ethylene in the solution by bubbling, promote gas-liquid mass transfer, and enhance the solubility of the gas raw material such as ethylene in the solution. If the gas inlet port is arranged at the top of the reaction device, the contact area with the reaction solution will be reduced, and the purpose of promoting gas-liquid mass transfer cannot be achieved.

[0012] In the present application, the gas dispersion device can be a conventional gas dispersion device in the art, preferably a gas distributor. The gas distributor can be a loop-type gas distributor. The loop-type gas distributor can be a conventional double-layer loop-type gas distributor in the art, and the structure of the double-layer loop-type gas distributor can include the following features: a cross-shaped gas distribution conduit in the center, and the cross-shaped conduits in the center of the two layers of gas distribution rings are staggered at 45 degrees; a circle of small holes is formed on the inner side and the outer side of each layer of loop, and the inner side small holes are inclined at 30 degrees below the horizontal axis, and the outer side small holes are flush with the horizontal axis. The pore size of the double-layer loop-type gas distributor is generally 1-10 mm, for example, 1.5 mm. The diameter of the loop distributor can be set according to the inner diameter of the reaction kettle, for example, 200 mm.

[0013] In the present application, the height-diameter ratio of the reaction device can be set according to the specific process, generally 1-1.3.

[0014] In the present application, the reaction product of the first gas outlet enters the fluid mixing and conveying equipment, which is beneficial to the adjustment of the pressure in the reaction device on the one hand, and the secondary gas-liquid mixing of the reaction product in the fluid mixing and conveying equipment on the other hand, thereby enhancing the solubility of ethylene in the solution and promoting the forward progress of the reaction.

[0015] In the present application, the fluid mixing and conveying equipment can be conventional in the art, preferably an ejector. The ejector can be conventional in the art, for example, a Venturi ejector.

[0016] In the present application, the outlet of the fluid mixing and conveying equipment is preferably located at (3 / 4)-(4 / 5) of the height of the reaction device. The height refers to the effective vertical height of the reaction device.

[0017] In the present application, the gas dispersion device is preferably located at (1 / 4)-(1 / 3) of the height of the reaction device.

[0018] In the present application, preferably, a second gas outlet is provided at the top of the reaction device, and the second gas outlet of each reaction device is connected in parallel to a pipeline, and a pressure control device is provided on the pipeline. The pressure control device can be a conventional device in the art, for example, a back pressure valve.

[0019] In the present application, the liquid inlet of the reaction device is generally located at the top of the reaction device.

[0020] In the present application, the reaction device can be a conventional reaction device in the art, for example, a kettle-type reactor. The reaction device can include a heat exchange device and a heat preservation device, and the heat exchange device is preferably a heat exchange jacket.

[0021] In the present application, the heat exchange device is preferably connected to the liquid outlet of the reaction device by a pump. The heat exchange device can be conventional in the art, for example a heat exchanger.

[0022] In the present application, the reaction device can or can not comprise a stirring device, and preferably the reaction device does not comprise a stirring device.

[0023] In the present application, the first reaction device of the norbornene reaction system can be used for the reaction of dicyclopentadiene and ethylene; the second reaction device can be used for the reaction of the intermediate product after the reaction of the first reaction device and ethylene. Those skilled in the art know that the intermediate product after the reaction of the first reaction device also comprises poly norbornene.

[0024] The present application provides a norbornene reaction method, which uses the norbornene reaction system as described above, and comprises:

[0025] S1, dicyclopentadiene solution and ethylene fed from the gas inlet of the first reaction device are reacted in the first reaction device;

[0026] wherein the gas from the first gas outlet of the first reaction device and part of the reaction liquid after heat exchange by the heat exchange device in the circulation loop from the liquid outlet are mixed to obtain a mixed liquid in a fluid mixing and conveying device, and the mixed liquid is reacted in the first reaction device;

[0027] S2, the remaining part of the reaction liquid from the liquid outlet of the first reaction device enters the second reaction device, and ethylene fed from the gas inlet of the second reaction device is reacted to obtain a reaction product, and the reaction product is discharged from the liquid outlet of the second reaction device;

[0028] wherein the gas from the first gas outlet of the second reaction device and part of the reaction product after heat exchange by the heat exchange device in the circulation loop from the liquid outlet are mixed to obtain a mixed liquid in a fluid mixing and conveying device, and the mixed liquid is reacted in the second reaction device.

[0029] In the present application, the ratio of the liquid discharge amount into the circulation loop to the total liquid discharge amount from the liquid outlet is preferably (0.1-0.6) : 1, more preferably (0.2-0.4) : 1, for example 0.4 : 1. The ratio of the liquid discharge amount into the circulation loop to the total liquid discharge amount from the liquid outlet can also be referred to as the reflux ratio.

[0030] In the present application, the sum of the mass of the reaction product of the part and the reaction product of the remaining part is equal to the total liquid discharge mass from the liquid discharge port.

[0031] In the present application, the reaction temperature in the first reaction device is preferably 180-280°C, more preferably 210-240°C, for example 230°C.

[0032] In the present application, the reaction temperature in the second reaction device is preferably 180-280°C, more preferably 230-240°C, for example 235°C.

[0033] In the present application, the reaction pressure in the first reaction device and / or the second reaction device is preferably 2-10 MPa, more preferably 5-7 MPa, for example 5 or 7 MPa.

[0034] In the present application, the reaction residence time of the first reaction device is preferably 5-120 min, more preferably 5-80 min, for example 23 min, 35 min, 46 min, 70 min or 76 min. The reaction residence time of the second reaction device is preferably 0.5-60 min, more preferably 0.5-30 min, for example 8 min, 11 min, 14 min, 22 min or 30 min.

[0035] In the present application, the total reaction residence time of the norbornene reaction method is preferably 5.5-180 min, more preferably 5.5-110 min, for example 60 min, 46 min, 31 min, 100 min or 98 min.

[0036] In the present application, the temperature before heat exchange in step S1 and / or step S2 is preferably 180-280°C. The temperature after heat exchange can be 30-150°C, for example 50°C or 75°C, preferably 30-50°C.

[0037] In the present application, the injection pressure of the fluid mixing and conveying device is preferably 1-5 MPa. The temperature of the fluid mixing and conveying device can be 30-150°C, for example 75°C or 90°C.

[0038] In the present application, the feeding amount of the dicyclopentadiene solution in the first reaction device is preferably 0.85-2.5 mL / s.

[0039] In the present application, the feeding amount of ethylene in the first reaction device is preferably 2.5-7.5 mL / s.

[0040] In the present application, the feeding amount of ethylene in the second reaction device is preferably 0.8-2 mL / s, for example 1.0 mL / s.

[0041] In the present application, the molar ratio of ethylene to dicyclopentadiene in the first reaction device is preferably 6-18, for example 10.

[0042] In the present application, the mass concentration of dicyclopentadiene in the dicyclopentadiene solution is preferably 15-60 wt%, for example 40 wt%. The mass concentration refers to the ratio of the mass of dicyclopentadiene to the total mass of the dicyclopentadiene solution.

[0043] In the present application, the solvent of the dicyclopentadiene solution can be conventional in the art, for example one or more of aromatic hydrocarbons, alkanes, cycloalkanes, substituted cycloalkanes and esters; the aromatic hydrocarbons are preferably one or more of benzene, toluene, xylene and trimethylbenzene; the number of carbon atoms of the aromatic hydrocarbons is more preferably 8-16; the number of carbon atoms of the cycloalkanes and / or substituted cycloalkanes is more preferably 6-16. The esters are preferably one or more of n-butyl acetate and n-octyl acetate.

[0044] As known by those skilled in the art, the abbreviation of dicyclopentadiene is DCPD.

[0045] On the basis of common knowledge in the art, the above-mentioned preferred conditions can be combined arbitrarily, i.e. to obtain each preferred example of the present application.

[0046] The reagents and raw materials used in the present application are commercially available.

[0047] The positive progress effect of the present application is that:

[0048] 1. The norbornene reaction system of the present application can effectively remove the reaction heat, prevent the temperature and pressure of the reaction device from being out of control, expand the dispersion degree of the gas raw material such as ethylene in the solution, promote the gas-liquid mass transfer, enhance the solubility of the gas raw material such as ethylene in the solution, promote the reaction efficiency, and thus obtain higher norbornene selectivity and dicyclopentadiene conversion rate, by setting at least two reaction devices connected in series comprising an external circulation loop, and the synergistic effect between the devices.

[0049] 2. The norbornene reaction method of the present application is safe, and has high norbornene selectivity and dicyclopentadiene conversion rate. BRIEF DESCRIPTION OF DRAWINGS

[0050] Figure 1 It is a process schematic diagram of the norbornene reaction system of Example 1.

[0051] Figure 2 It is a process schematic diagram of the norbornene reaction system of Comparative Example 3.

[0052] Figure 3 It is a process schematic diagram of the norbornene reaction system of Comparative Example 4.

[0053] Figure 4 The main reaction process of the norbornene reaction method of Example 1.

[0054] Explanation of reference signs:

[0055] Kettle reactor 1

[0056] Liquid feed port 2

[0057] Gas feed port 3

[0058] Gas distributor 4

[0059] Liquid discharge port 5

[0060] Pump 6

[0061] Heat exchanger 7

[0062] Venturi ejector 8

[0063] First gas outlet 9

[0064] Second gas outlet 10

[0065] Back pressure valve 11 DETAILED DESCRIPTION

[0066] The present application is further illustrated by the following examples, but the present application is not limited to the scope of the examples. The experimental methods in the following examples, for which no specific conditions are indicated, are carried out according to conventional methods and conditions, or according to the instructions of the commercial products.

[0067] Example 1

[0068] The process schematic of the norbornene reaction system of Example 1 is shown in Figure 1 which includes two reaction devices 1 (kettle reactors) connected in series, which are a first kettle reactor and a second kettle reactor, respectively.

[0069] In each reaction device 1, a circulation loop is provided, which is led out from the first gas outlet 9 at the top, is communicated with the gas inlet of the venturi ejector 8, and is further communicated with the upper part of the reaction device 1. Each kettle reactor 1 is provided with a circulation loop, which is led out from the liquid discharge port 5 at the bottom, is communicated with the heat exchanger 7 and the venturi ejector 8 in turn, and is returned to the upper part of the kettle reactor 1.

[0070] The lower part of each tank reactor 1 is also provided with a gas distributor 4 connected with the gas inlet 3 at the bottom of the tank reactor 1. The gas distributor 4 is a double-layer annular gas distributor with a cross-shaped gas distribution guide pipe in the center, and the cross-shaped guide pipes in the center of the two layers of gas distribution rings are staggered at 45 degrees. A circle of small holes is formed on the inner side and the outer side of each layer of annular pipe, respectively, with the inner side holes being inclined at 30 degrees below the horizontal axis and the outer side holes being flush with the horizontal axis, and the hole diameter being about 1.5 mm.

[0071] The height-diameter ratio of the reaction kettle is 1.2, and the diameter of the annular distributor is about 200 mm according to the inner diameter of the reaction kettle.

[0072] The heat exchange jacket is installed outside the two tank reactors 1. The volumes of the first tank reactor 1 and the second tank reactor 1 are 30 L and 10 L, respectively.

[0073] The first tank reactor is used for the reaction of dicyclopentadiene and ethylene;

[0074] The second tank reactor is used for the reaction of the intermediate product after the reaction of the first tank reactor and ethylene.

[0075] The outlet of the Venturi ejector 8 of the circulation loop is located at the (1 / 5)-(1 / 4) height of the tank reactor 1. The gas distributor 4 is located at the (2 / 3)-(3 / 4) height of the tank reactor 1.

[0076] The gas from the first gas outlet 9 enters the Venturi ejector 8, which is beneficial to the adjustment of the pressure in the tank reactor 1, and is also beneficial to the secondary gas-liquid mixing of the gas and the liquid discharged from the bottom liquid outlet 5 after heat exchange in the Venturi ejector 8, thereby enhancing the solubility of ethylene in the solution and promoting the forward reaction.

[0077] The top of the tank reactor 1 is also provided with a second gas outlet 10, and the second gas outlets 10 of each tank reactor 1 are connected in parallel to a pipeline, and a back pressure valve 11 is arranged on the pipeline.

[0078] The liquid inlet 2 of the tank reactor 1 is arranged at the top of the tank reactor 1.

[0079] The heat exchanger 7 is connected with the liquid outlet 5 of the tank reactor 1 through the pump 6.

[0080] The first tank reactor and the second tank reactor do not contain stirring devices.

[0081] A norbornene reaction method using the norbornene reaction system of Example 1, which comprises:

[0082] S1, the dicyclopentadiene solution and ethylene fed from the gas feed port 3 of the first tank reactor are reacted in the first tank reactor. In particular, after the ethylene gas enters the reaction tank through the feed port 3, the ethylene gas is broken into smaller bubbles after passing through the gas distributor 4 arranged at the bottom of the reaction tank, further strengthening the contact between the liquid material and the ethylene gas, thereby strengthening the reaction process; in addition, the arrangement of the gas distributor 4 can also make the distribution of the ethylene gas in the reaction solution more uniform, prevent the occurrence of local reaction hot spots in the reactor, and improve the safety of the process.

[0083] The gas from the first gas outlet 9 of the first tank reactor and the reaction liquid after heat exchange in the heat exchanger 7 in the circulation loop are mixed in the Venturi ejector 8 to obtain a mixed liquid, and the mixed liquid is then introduced into the first tank reactor for reaction.

[0084] The advantage of using the Venturi ejector 8 is that a part of the gas-liquid mixing process can be carried out inside the ejector, strengthening the mass transfer of the gas-liquid two-phase material; at the same time, after the liquid material is ejected from the Venturi ejector 8, it is in a highly dispersed state, passing through the gas phase region at the upper part of the reactor, further strengthening the mass transfer process of the gas-liquid two-phase inside the reactor.

[0085] S2, the remaining part of the reaction liquid from the liquid discharge port 5 of the first tank reactor enters the second tank reactor, and the ethylene fed from the gas feed port 3 of the second tank reactor is reacted to obtain a reaction product, which is discharged from the liquid discharge port 5 of the second tank reactor;

[0086] Among them, the gas from the first gas outlet 9 of the second tank reactor and the reaction product after heat exchange in the heat exchanger 7 in the circulation loop are mixed in the Venturi ejector 8 to obtain a mixed liquid, and the mixed liquid is introduced into the second tank reactor for reaction.

[0087] The feed amount of the dicyclopentadiene solution in the first tank reactor is 0.85 mL / s. The solvent of the dicyclopentadiene solution is toluene.

[0088] The feed amount of ethylene in the first tank reactor is 2.5 mL / s.

[0089] The feed amount of ethylene in the second tank reactor is 1.0 mL / s.

[0090] In steps S1 and S2, the ratio of the liquid discharge amount entering the circulation loop to the total liquid discharge amount from the liquid discharge port 5 is 0.4:1.

[0091] The temperature of the reaction liquid from the liquid outlet 5 of the first tank reactor was 230°C, and the temperature after heat exchange was 50°C. The pressure of the Venturi ejector 8 in the circulation loop of the first tank reactor was 5 MPa, and the temperature was 75°C.

[0092] The temperature of the reaction liquid from the liquid outlet 5 of the second tank reactor was 235°C, and the temperature after heat exchange was 75°C. The pressure of the Venturi ejector 8 in the circulation loop of the second tank reactor was 5 MPa, and the temperature was 90°C.

[0093] The main reaction of the norbornene reaction method in Example 1 was mainly: DCPD underwent thermal decomposition reaction to generate cyclopentadiene (i.e., CPD), and ethylene reacted with CPD to produce norbornene (i.e., NB); the side reactions included: further reaction of CPD and NB; and polymerization of DCPD and CPD, as shown in the following reaction formula: Figure 4

[0094] The adiabatic temperature rise of the norbornene reaction method in Example 1 was about 303 K.

[0095] Note: The adiabatic temperature rise Δt can be calculated according to the following formula:

[0096] Q = cmΔt, wherein Q is the heat of reaction, c is the specific heat capacity, and m is the reaction amount. For Q and c of a specific reaction and a system, they can be directly obtained by consulting relevant technical manuals or calculated by thermodynamic formula.

[0097] Examples 2-5

[0098] Examples 2-5 used the same norbornene reaction system as Example 1.

[0099] The norbornene reaction method of Examples 2-5 was the same as that of Example 1, and the only difference was that the mass concentration of the dicyclopentadiene solution, the molar ratio of ethylene to dicyclopentadiene, the reaction temperature, the reaction pressure, and the residence time were different.

[0100] In Examples 1-5, the specific process conditions of the first tank reactor included reaction conditions, reaction residence time, liquid phase outlet concentration of norbornene, DCPD conversion rate, etc., as shown in Table 1; the reaction conditions, residence time, liquid phase outlet concentration of norbornene, DCPD conversion rate, and selectivity of norbornene of the second tank reactor were as shown in Table 2. Among them, norbornene (wt%) refers to the mass content of norbornene in the liquid phase outlet as analyzed by gas chromatography.

[0101] Table 1. Process parameters of the first tank reactor

[0102]

[0103] Table 2. Process parameters of the second tank reactor​

[0104]

[0105] In Examples 1-5 and Comparative Examples 1-3 below, the conversion of DCPD is defined as:

[0106]

[0107] The selectivity of norbornene (i.e. NB) is defined as:

[0108]

[0109] Comparative Example 1

[0110] The norbornene reaction system of Comparative Example 1 differs from Example 1 in that it does not have a second tank reactor connected in series, but only uses a first tank reactor 1 with a circulation loop. The conditions of the first tank reactor 1 are the same as in Example 1. The volume of the first tank reactor 1 is 30 L.

[0111] The norbornene reaction method of Comparative Example 1 comprises the following steps:

[0112] S1, the solution of dicyclopentadiene and ethylene fed from the gas inlet port 3 of the first tank reactor 1 are reacted in the first tank reactor 1;

[0113] S2, part of the reaction product from the liquid outlet port 5 of the first tank reactor 1 is heated by the circulation loop and then enters the first tank reactor 1 for reaction;

[0114] At the same time, the remaining part of the reaction product from the liquid outlet port 5 of the first tank reactor 1 is discharged from the system.

[0115] The operating conditions of the first tank reactor 1 and its circulation loop of Comparative Example 1 are the same as in Example 1.

[0116] Comparative Example 2

[0117] The norbornene reaction system of Comparative Example 2 differs from Example 1 in that it does not have a second tank reactor connected in series, but only uses a first tank reactor 1 with a circulation loop.

[0118] The operating conditions of the first tank reactor 1 and its circulation loop of Comparative Example 2 are the same as in Example 3.

[0119] The residence time is different, and the process conditions and reaction results of Examples 1, 3 and Comparative Examples 1, 2 are shown in Table 3.

[0120] Table 3. Specific process parameters of Examples 1, 3 and Comparative Examples 1, 2

[0121]

[0122] From Table 3, it can be seen that, compared with Comparative Example 1, by adding the second tank reactor in series, the liquid-phase outlet concentration of norbornene, the conversion rate of DCPD and the selectivity of norbornene are improved. Compared with Comparative Example 2, the total residence time of Example 3 is only 31 min, and by adding the second tank reactor in series, the liquid-phase outlet concentration of norbornene, the conversion rate of DCPD and the selectivity of norbornene are significantly improved. Compared with the single first tank reactor, by adding the second tank reactor in series, Examples 1 and 3 are more conducive to strengthening the reaction rate in the case that the concentration of reactants in the system is low in the later stage of the reaction.

[0123] Comparative Example 3:

[0124] The norbornene system of Comparative Example 3 was prepared using a 30L stainless steel tank reactor 1 (batch reactor) with a push-type stirring paddle as shown in Figure 2 The tank reactor 1 was equipped with a heat exchanger 7 (i.e. a condenser, cooling liquid temperature 20℃) with a volume of 5L above the tank cover, and the tank reactor 1 was externally equipped with a heat exchange jacket. A circulation loop was provided on the tank cover of the tank reactor 1, which led out from the first gas outlet 9, was connected to the heat exchanger 7, and then returned to the top of the tank reactor 1. A back pressure valve 11 was also provided on the pipeline of the first gas outlet 9, for controlling the pressure of the tank reactor 1.

[0125] The norbornene reaction method of Comparative Example 3 was that the dicyclopentadiene and ethylene were reacted in the tank reactor 1, and the gas from the first gas outlet 9 of the tank reactor 1 was heated in the circulation loop and then entered the tank reactor 1 for reaction.

[0126] Before the reaction, 15L of 40wt% dicyclopentadiene toluene solution was pumped 6 into the tank reactor 1, heated to 240℃, started stirring (stirring speed 400rpm), and ethylene gas was introduced from above the tank reactor 1 to 6MPa, and kept for 60min.

[0127] The specific process parameters of Comparative Example 3 are shown in the following table:

[0128] Table 4. Specific process parameters of Comparative Example 3

[0129]

[0130] As shown in Table 4, compared with the traditional batch reactor with heat removal function such as Comparative Example 3, the reaction system of Example 1 is more likely to obtain higher selectivity of norbornene under the condition of high DCPD conversion. In addition, the reaction system used in Example 1 has higher removal efficiency and faster response for the accumulated heat in the system compared with the heat exchange mode of the rising organic vapor in the batch reactor in Comparative Example 3, and thus has higher safety.

[0131] Comparative Example 4:

[0132] The process schematic diagram of the norbornene system of Comparative Example 4 is shown in Figure 3 The process schematic diagram of the norbornene system of Comparative Example 4 is shown in

[0133] The norbornene reaction method of Comparative Example 4 is that the preheated dicyclopentadiene and ethylene are reacted in the tank reactor 1, and the gas from the first gas outlet 9 of the tank reactor 1 is heated by the circulation loop and then enters the tank reactor 1 for reaction.

[0134] The feeding speed of 40wt% dicyclopentadiene toluene solution is 1mL / s, the feeding speed of ethylene gas is 2.5mL / s, the reaction temperature is 235℃, and the reaction pressure is 5MPa.

[0135] When the reaction reaches the stable stage for 35min (i.e. the feeding and discharging speed in the tank reaches the balance, the reaction temperature and pressure reach the set value), the reactor appears a temperature rise of 30℃, and the pressure in the tank rises to 5.5MPa, and then the coolant is injected into the reactor jacket to stop the reaction to prevent risks. It can be seen that the norbornene system of Comparative Example 4 has lower safety in the process of generating norbornene, while the norbornene reaction system of Examples 1-5 of the present application can effectively remove the reaction heat to prevent the temperature and pressure of the reactor from being out of control, has high safety, and has high DCPD conversion and norbornene selectivity.

Claims

1. A norbornene reaction process characterized by, The reaction system comprises at least two reaction devices connected in series, Each reaction device is provided with a circulation loop leading from the first gas outlet at the top to the gas inlet of a fluid mixing and conveying device, and then to the upper part of the reaction device; Each reaction device is also provided with a circulation loop leading from the liquid outlet at the bottom to the liquid inlet of the fluid mixing and conveying device, and then to the upper part of the reaction device, through a heat exchange device; The fluid mixing and conveying device is a Venturi ejector; The lower part of the reaction device is also provided with a gas dispersion device connected to the gas inlet at the bottom of the reaction device; The method comprises the following steps: S1, the dicyclopentadiene solution and ethylene fed from the gas inlet of the first reaction device are reacted in the first reaction device; The gas from the first gas outlet of the first reaction device and part of the reaction liquid from the liquid outlet after heat exchange in the heat exchange device in the circulation loop are mixed in the fluid mixing and conveying device to obtain a mixed liquid, which is fed into the first reaction device for reaction; S2, the remaining part of the reaction liquid from the liquid outlet of the first reaction device is fed into the second reaction device, and reacts with ethylene fed from the gas inlet of the second reaction device to obtain a reaction product, which is discharged from the liquid outlet of the second reaction device; The gas from the first gas outlet of the second reaction device and part of the reaction product from the liquid outlet after heat exchange in the heat exchange device in the circulation loop are mixed in the fluid mixing and conveying device to obtain a mixed liquid, which is fed into the second reaction device for reaction; The gas dispersion device is arranged at 1 / 4-1 / 3 of the height of the reaction device. the molar ratio of the ethylene to the dicyclopentadiene of the dicyclopentadiene solution in the first reaction device is 10-18; the reaction temperature in the first reaction device is 230-240 ° C; The reaction temperature in the second reaction apparatus is 235-240 ° C.

2. The norbornene reaction process of claim 1 wherein, The gas dispersion device is a gas distributor.

3. The norbornene reaction process according to claim 2, wherein The gas distributor is a loop-type gas distributor.

4. The norbornene reaction process of claim 3 wherein, The top of the reaction device is provided with a second gas outlet, and the second gas outlets of each reaction device are connected in parallel to a pipe, which is provided with a pressure control device; 5. The norbornene reaction process of claim 1 wherein, The outlet of the fluid mixing and conveying device is arranged at 3 / 4-4 / 5 of the height of the reaction device. The pressure control device is a back pressure valve.

6. The norbornene reaction process according to claim 5, wherein The liquid inlet of the reaction device is arranged at the top of the reaction device; 7. The norbornene reaction process of claim 1 wherein, The reaction device is a tank reactor; The heat exchange device is connected to the liquid outlet of the reaction device by a pump. In step S1 and / or step S2, the ratio of the liquid discharge amount entering the circulation loop to the total liquid discharge amount from the liquid outlet is (0.1-0.6):

1.

8. The norbornene reaction process of claim 1 wherein, In step S1 and / or step S2, the ratio of the liquid discharge amount entering the circulation loop to the total liquid discharge amount from the liquid outlet is (0.2-0.4):

1.

9. The norbornene reaction process according to claim 8, wherein ​ 10. The norbornene reaction process of claim 1 wherein, The reaction pressure of the first reaction device and / or the second reaction device is 2-10 MPa.

11. The norbornene reaction process according to claim 10, wherein The reaction pressure of the first reaction device and / or the second reaction device is 5-7 MPa.

12. The norbornene reaction process according to claim 1 wherein, The reaction residence time of the first reaction device is 5-120 min; The reaction residence time of the second reaction device is 0.5-60 min; The total reaction residence time of the norbornene reaction method is 5.5-180 min.

13. The norbornene reaction process of claim 12 wherein, The reaction residence time of the first reaction device is 5-80 min; The reaction residence time of the second reaction device is 0.5-30 min; The total reaction residence time of the norbornene reaction method is 5.5-110 min.

14. The norbornene reaction process of claim 13 wherein, The reaction residence time of the first reaction device is 23 min, 35 min, 46 min, 70 min or 76 min; The reaction residence time of the second reaction device is 8 min, 11 min, 14 min, 22 min or 30 min; The total reaction residence time of the norbornene reaction method is 60 min, 46 min, 31 min, 100 min or 98 min.

15. The norbornene reaction process of claim 1 wherein, In step S1 and / or step S2, the temperature before heat exchange is 180-280℃; and the temperature after heat exchange is 30-150℃. The injection pressure of the fluid mixing and conveying device is 1-5 MPa; and the temperature of the fluid mixing and conveying device is 30-150℃.

16. The norbornene reaction process of claim 15 wherein, In step S1 and / or step S2, the temperature after heat exchange is 50℃ or 75℃. The temperature of the fluid mixing and conveying device is 75℃ or 90℃.

17. The norbornene reaction process of claim 15 wherein, In step S1 and / or step S2, the temperature after heat exchange is 30-50℃.

18. The norbornene reaction process of claim 1 wherein, The feeding amount of the dicyclopentadiene solution in the first reaction device is 0.85-2.5 mL / s; The feeding amount of ethylene in the first reaction device is 2.5-7.5 mL / s; The feeding amount of ethylene in the second reaction device is 0.8-2 mL / s; and / or the mass concentration of dicyclopentadiene in the dicyclopentadiene solution is 15-60 wt%.

19. The norbornene reaction process of claim 18 wherein, The feeding amount of ethylene in the second reaction device is 1.0 mL / s; The mass concentration of dicyclopentadiene in the dicyclopentadiene solution is 40 wt%.

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