Production method and equipment of cyclopentadiene

Abstract

The invention relates to a method for producing cyclopentadiene, which comprises the following step of: cracking dicyclopentadiene in the presence of methyl pyrrolidone (NMP) to prepare the cyclopentadiene. According to the production method of cyclopentadiene, the NMP is used as a diluent, so that the problems of coking and curing of components can be effectively solved, the transfer frequency and the rectifying still cleaning frequency can be conveniently reduced, and the production steps are simplified; and meanwhile, the filler is replaced by PFA / PTFE with higher corrosion resistance and purity to replace metal or ceramic, so that introduction of impurities is effectively avoided. According to the cyclopentadiene production equipment disclosed by the invention, the secondary condenser is additionally arranged, so that generated cyclopentadiene can be rapidly cooled, and polymerization of the generated cyclopentadiene is prevented; in addition, the production equipment of cyclopentadiene is additionally provided with a solvent recycling device, so that the cost can be effectively reduced, and the production equipment is suitable for large-scale industrial production.

Description

Technical Field

[0001] The invention relates to the field of chemical industry, and in particular to a method and equipment for producing cyclopentadiene. Background Art

[0002] CPD (cyclopentadiene) is an organic compound with the chemical formula C5H6, mainly used as an organic synthesis intermediate. It has a conjugated double bond structure, which means that the electrons in the CPD molecule are not limited to a certain area, but have a larger range of electron activity, and the electrons are delocalized to form a conjugated system. The unstable chemical structure allows CPD to undergo a variety of chemical reactions, opening up more small branches for the chemical research of petroleum products, such as CPD's redox, halogenation substitution, polymerization condensation, unsaturated addition, etc. It is widely used in synthetic rubber, engineering plastics, new resins, flame retardants, curing agents, and cyclopentadiene compounds.

[0003] The quality of CPD downstream products has certain requirements on the purity of CPD raw materials. Obtaining high-purity CPD has an important impact on the development of CPD derivative application fields and the improvement of market value. Based on the property that CPD and DCPD (dicyclopentadiene) can be converted into each other, using DCPD to produce high-purity CPD will also be an inevitable prerequisite for the development of CPD downstream products.

[0004] Since CPD and DCPD can be converted into each other, the cracked CPD needs to be separated in time during the preparation process. At the same time, CPD can self-polymerize into DCPD at room temperature, so the cracked CPD needs to be cooled down quickly and stored at low temperature. At the same time, DCPD and the CPD generated by the reaction are easy to copolymerize to form polymers, causing coking and reducing the product yield. Summary of the invention

[0005] Problem that the invention aims to solve

[0006] In view of the above problems existing in the prior art, the object of the present invention is to provide a CPD preparation method and equipment capable of timely separating products and cooling.

[0007] Solutions for solving problems

[0008] The present invention provides a method for producing cyclopentadiene, which comprises cracking dicyclopentadiene in the presence of methylpyrrolidone (NMP) to prepare the cyclopentadiene.

[0009] Preferably, the method comprises the following steps:

[0010] (1) using an inert gas to pressurize the preparation raw materials and diluent into a first reaction kettle, and heating and cracking them;

[0011] (2) using a primary condenser to collect the gas phase components produced in step (1);

[0012] (3) The product collected in step (2) is cooled by a secondary condenser and stored at low temperature.

[0013] Preferably, the volume ratio of the inert gas to the raw material and the diluent in step (1) is 2:1 to 2:5;

[0014] In step (1), the inert gas is nitrogen, the raw material is dicyclopentadiene, and the diluent is NMP;

[0015] The heating in step (1) is heating to 170-200°C.

[0016] Preferably, the gas phase component in step (2) is a gas phase component at 41-44°C;

[0017] The reflux ratio of step (2) is 1:1 to 1:5.

[0018] Preferably, the cooling in step (3) is cooling to 0-5°C;

[0019] The low temperature storage in step (3) is storage at -5 to -10°C.

[0020] Preferably, the method further comprises the steps of:

[0021] (4) The residue in the first reactor is transferred into a second reactor for distillation to separate the diluent.

[0022] Preferably, the reaction temperature of the distillation is 150-180°C and the reaction pressure is 0.5-2Kpa;

[0023] The reflux ratio of step (4) is 1:1 to 1:3.

[0024] The present invention also provides a device for producing cyclopentadiene, the device comprising:

[0025] A first distillation kettle (20) for heating dicyclopentadiene and NMP;

[0026] a first distillation tower (24), the first distillation tower (24) being in communication with the first distillation kettle (20) to separate products from the first distillation kettle (20), the first distillation tower (24) being provided with a temperature sensor;

[0027] A first collecting device, comprising a first primary condenser (30), a first secondary condenser (32) and a product tank (33), wherein the discharge port of the first rectification tower (24) is connected to the inlet of the first primary condenser (30), and the first secondary condenser (32) is connected between the first primary condenser (30) and the product tank (33), and is connected to the product tank (33);

[0028] a secondary distillation device, connected to the first distillation kettle (20) to perform secondary distillation on the material flowing out of the first distillation kettle (20), wherein the secondary distillation device is provided with a temperature sensor;

[0029] The second collecting device comprises a second primary condenser (50) and a second secondary condenser (52), wherein the discharge port of the secondary distillation device is connected to the inlet of the second primary condenser (50), and the second secondary condenser (52) is located downstream of the second primary condenser (50), and the outlet is connected to the solvent storage tank (13) to perform secondary condensation and recovery on the material.

[0030] Preferably, the first collecting device further comprises a first reflux tank (31);

[0031] The outlet of the first primary condenser (30) is communicated with the inlet of the first reflux tank (31), one outlet of the first reflux tank (31) is communicated with the inlet of the first secondary condenser (32), the other outlet of the first reflux tank is communicated with the first distillation tower (24), and the outlet of the first secondary condenser (32) is communicated with the product tank (33);

[0032] The second collecting device further comprises a second reflux tank (51), the discharge port of the second distillation tower (43) is communicated with the inlet of the second primary condenser (50), the outlet of the second primary condenser (50) is communicated with the inlet of the second reflux tank (51), one outlet of the second reflux tank (51) is communicated with the second secondary condenser (52), and the other outlet of the second reflux tank (51) is communicated with the product tank (33);

[0033] The secondary distillation device comprises a second distillation kettle (40) and a second distillation tower (43); the second distillation kettle (40) is connected to the first distillation kettle (20) and the second distillation tower (43) respectively to perform secondary distillation on the material flowing out of the first distillation kettle (20); the second distillation kettle (40) is also connected to a recovery tank (42);

[0034] The temperature sensor is provided on the second distillation tower (43).

[0035] Preferably, the fillers of the first distillation tower (24) and the second distillation tower (43) are high-purity PFA / PTFE rings with a diameter-to-height ratio of 1:5 to 1:50.

[0036] Preferably, the first distillation tower (24) and the second distillation tower (43) are divided into three sections, each section being provided with a temperature sensor.

[0037] Effects of the Invention

[0038] The production method of cyclopentadiene of the present invention uses NMP as a diluent, which can effectively solve the problems of component coking and solidification, is convenient for reducing the number of transfers and the number of cleaning times of the distillation kettle, and simplifies the production steps; at the same time, the filler is replaced with corrosion-resistant PFA / PTFE with higher purity to replace metal or ceramic, which effectively avoids the introduction of impurities.

[0039] The cyclopentadiene production equipment of the present invention is provided with a secondary condenser, which can rapidly cool the generated cyclopentadiene to prevent it from polymerizing; the cyclopentadiene production equipment of the present invention is also provided with a solvent recycling device, which can recycle more than 80% of the solvent, effectively reducing the cost and the pressure of liquid waste treatment, being green and environmentally friendly, and being suitable for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 Schematic diagram of cyclopentadiene production equipment.

[0041] Description of reference numerals:

[0042] 10-raw material storage tank, 11-jacket, 12-bottom tube, 13-solvent storage tank, 14-bottom tube, 20-first distillation kettle, 21-jacket, 22-magnetic stirring, 23-bottom valve, 24-first distillation tower, 25-temperature sensor 1, 26-temperature sensor 2, 27-temperature sensor 3, 30-first primary condenser, 31-first reflux tank, 32-first secondary condenser, 33-product tank, 34-jacket, 35-transfer pump, 40-second distillation kettle, 41-jacket, 42-recovery tank, 43-second distillation tower, 44-temperature sensor 1, 45-temperature sensor 2, 46-temperature sensor 3, 50-second primary condenser, 51-second reflux tank, 52-second secondary condenser. DETAILED DESCRIPTION

[0043] In order to make the technical solutions and beneficial effects of the present invention more clearly understandable, the following is a detailed description by listing specific embodiments. The drawings are not necessarily drawn to scale, and local features may be enlarged or reduced to more clearly show the details of the local features; unless otherwise defined, the technical and scientific terms used herein have the same meanings as those in the technical field to which this application belongs.

[0044] The present invention provides a method for producing cyclopentadiene, which comprises cracking dicyclopentadiene in the presence of methylpyrrolidone (NMP) to prepare the cyclopentadiene.

[0045] In certain embodiments, the method comprises the steps of:

[0046] (1) using an inert gas to pressurize the preparation raw materials and diluent into a first reaction kettle, and heating and cracking them;

[0047] (2) using a primary condenser to collect the gas phase components produced in step (1);

[0048] (3) The product collected in step (2) is cooled by a secondary condenser and stored at low temperature.

[0049] In certain embodiments, the volume ratio of the inert gas to the raw materials and diluent in step (1) is 2:1 to 2:5.

[0050] In certain embodiments, the volume ratio of the inert gas to the raw materials and the diluent in step (1) is 2:1, or 2:2, or 2:3, or 2:4, or 2:5.

[0051] In certain embodiments, the volume ratio of the inert gas to the preparation raw materials and the diluent in step (1) is 2:2.

[0052] In certain embodiments, the inert gas in step (1) is nitrogen, the raw material is dicyclopentadiene, and the diluent is NMP.

[0053] In certain embodiments, the heating in step (1) is heating to 170-200°C.

[0054] In certain embodiments, the heating in step (1) is heating to 170°C, or 175°C, or 180°C, or 185°C, or 190°C, or 195°C, or 200°C.

[0055] In certain embodiments, the gas phase component in step (2) is a gas phase component at 41-44°C.

[0056] In certain embodiments, the reflux ratio of step (2) is 1:1 to 1:5.

[0057] In certain embodiments, the reflux ratio of step (2) is 1:1, or 1:2, or 1:3, or 1:4, or 1:5.

[0058] In certain embodiments, the reflux ratio of step (2) is 1:3.

[0059] In certain embodiments, the cooling in step (3) is cooling to 0-5°C.

[0060] In certain embodiments, the cooling in step (3) is cooling to 0°C, or 1°C, or 2°C, or 3°C, or 4°C, or 5°C.

[0061] In certain embodiments, the cooling in step (3) is cooling to 2°C.

[0062] In certain embodiments, the low temperature storage in step (3) is storage at -5 to -10°C.

[0063] In certain embodiments, the low temperature storage in step (3) is -5°C, -6°C, -7°C, -8°C, -9°C, or -10°C.

[0064] In certain embodiments, the cryopreservation in step (3) is storage at -5°C.

[0065] In certain embodiments, the method further comprises the steps of:

[0066] (4) The residue in the first reactor is transferred into a second reactor for distillation to separate the diluent.

[0067] In certain embodiments, the reaction temperature of the distillation is 150-180° C., and the reaction pressure is 0.5-2 KPa.

[0068] In certain embodiments, the reaction temperature of the distillation is 150°C, or 155°C, or 160°C, or 165°C, or 170°C, or 175°C, or 180°C.

[0069] In certain embodiments, the reaction temperature of the distillation is 160°C.

[0070] In certain embodiments, the reaction pressure of the distillation is 0.5Kpa, or 0.6Kpa, or 0.7Kpa, or 0.8Kpa, or 0.9Kpa, or 1Kpa, or 1.1Kpa, or 1.2Kpa, or 1.3Kpa, or 1.4Kpa, or 1.5Kpa, or 1.6Kpa, or 1.7Kpa, or 1.8Kpa, or 1.9Kpa, or 2Kpa.

[0071] In certain embodiments, the reaction pressure of the distillation is 1 KPa.

[0072] In certain embodiments, the reflux ratio of step (4) is 1:1 to 1:3.

[0073] In certain embodiments, the reflux ratio of step (4) is 1:1, or 1:2, or 1:3.

[0074] In certain embodiments, the reflux ratio of step (4) is 1:1.

[0075] The present invention also provides a device for producing cyclopentadiene, the device comprising:

[0076] A first distillation kettle (20) for heating dicyclopentadiene and NMP;

[0077] a first distillation tower (24), the first distillation tower (24) being in communication with the first distillation kettle (20) to separate products from the first distillation kettle (20), the first distillation tower (24) being provided with a temperature sensor;

[0078] A first collecting device, comprising a first primary condenser (30), a first secondary condenser (32) and a product tank (33), wherein the discharge port of the first rectification tower (24) is connected to the inlet of the first primary condenser (30), and the first secondary condenser (32) is connected between the first primary condenser (30) and the product tank (33), and is connected to the product tank (33);

[0079] a secondary distillation device, connected to the first distillation kettle (20) to perform secondary distillation on the material flowing out of the first distillation kettle (20), wherein the secondary distillation device is provided with a temperature sensor;

[0080] The second collecting device comprises a second primary condenser (50) and a second secondary condenser (52), wherein the discharge port of the secondary distillation device is connected to the inlet of the second primary condenser (50), and the second secondary condenser (52) is located downstream of the second primary condenser (50), and the outlet is connected to the solvent storage tank (13) to perform secondary condensation and recovery on the material.

[0081] In certain embodiments, the first collecting device further comprises a first reflux tank (31).

[0082] In certain embodiments, the outlet of the first primary condenser (30) is connected to the inlet of the first reflux tank (31), one outlet of the first reflux tank (31) is connected to the inlet of the first secondary condenser (32), the other outlet of the first reflux tank is connected to the first distillation tower (24), and the outlet of the first secondary condenser (32) is connected to the product tank (33).

[0083] In some embodiments, the second collecting device further comprises a second reflux tank (51), the discharge port of the second distillation tower (43) is connected to the inlet of the second primary condenser (50), the outlet of the second primary condenser (50) is connected to the inlet of the second reflux tank (51), one outlet of the second reflux tank (51) is connected to the second secondary condenser (52), and the other outlet of the second reflux tank (51) is connected to the product tank (33). In some embodiments, the secondary distillation device comprises a second distillation kettle (40) and a second distillation tower (43), the second distillation kettle (40) is respectively connected to the first distillation kettle (20) and the second distillation tower (43) to perform secondary distillation on the material flowing out of the first distillation kettle (20), and the second distillation kettle (40) is also connected to the recovery tank (42).

[0084] In certain embodiments, the temperature sensor is provided on the second distillation tower (43).

[0085] In certain embodiments, the second collection device and the secondary distillation device are capable of recycling NMP.

[0086] In certain embodiments, the packings of the first distillation tower (24) and the second distillation tower (43) are high-purity PFA / PTFE rings.

[0087] In certain embodiments, the diameter-to-height ratio of the first distillation tower (24) and the second distillation tower (43) is 1:5 to 1:50.

[0088] In certain embodiments, the diameter-to-height ratio of the first distillation tower (24) to the second distillation tower (43) is 1:5, or 1:6, or 1:7, or 1:8, or 1:9, or 1:10, or 1:11, or 1:12, or 1:13, or 1:14, or 1:15, or 1:16, or 1:17, or 1:18, or 1:19, or 1:20, or 1:21, or 1:22, or 1:23, or 1:24, or 1:25. 25, or 1:26, or 1:27, or 1:28, or 1:29, or 1:30, or 1:31, or 1:32, or 1:33, or 1:34, or 1:35, or 1:36, or 1:37, or 1:38, or 1:39, or 1:40, or 1:41, or 1:42, or 1:43, or 1:44, or 1:45, or 1:46, or 1:47, or 1:48, or 1:49, or 1:50.

[0089] In certain embodiments, the diameter-to-height ratio of the first distillation tower (24) to the second distillation tower (43) is 1:25.

[0090] In certain embodiments, the first distillation tower (24) and the second distillation tower (43) are divided into three sections, each section being provided with a temperature sensor.

[0091] In certain embodiments, materials or products flow out from the top of the first distillation tower (24) and the second distillation tower (43).

[0092] In certain embodiments, the first distillation tower (24) is provided with a temperature sensor 1 (25), a temperature sensor 2 (26) and a temperature sensor 3 (27).

[0093] In certain embodiments, the temperature sensor 1 (25), the temperature sensor 2 (26) and the temperature sensor 3 (27) respectively measure the temperature in the three-stage first distillation tower (24).

[0094] In certain embodiments, the second distillation tower (43) is provided with a temperature sensor 1 (44), a temperature sensor 2 (45) and a temperature sensor 3 (46).

[0095] In certain embodiments, the temperature sensor 1 (44), the temperature sensor 2 (45) and the temperature sensor 3 (46) respectively measure the temperatures in the three-stage second distillation tower (43).

[0096] In certain embodiments, “□” is a refrigerant or a heat medium introduced into the device.

[0097] In certain embodiments, It is a pipe insulation device.

[0098] In certain embodiments, jackets are provided on the outside of the raw material storage tank (10), the first distillation kettle (20), the product tank (33), and the second distillation kettle (40).

[0099] In certain embodiments, the jacket is used for cooling or heating.

[0100] Example 1: Cracking of dicyclopentadiene

[0101] The dicyclopentadiene (DCPD) in the 2L raw material storage tank and the methylpyrrolidone (NMP) in the 2L solvent storage tank are pressed into the distillation kettle 1 through the bottom tube using 4 kg of nitrogen, and the distillation kettle 1 is heated to 175°C to crack the dicyclopentadiene. The gas phase components at 41-44°C in the distillation tower are collected and enter the primary condenser. The condensed materials enter the gas-liquid separation kettle, and the reflux ratio is adjusted to 1:3 through the mass flow controller of the branch. The gas phase components are refluxed into the distillation tower, and the collected liquid products are quickly cooled through the secondary condenser. After the temperature drops to 2°C, they flow into the product tank at -5°C for storage and standby.

[0102] The residual material and NMP in the distillation kettle 1 are transferred to the distillation kettle 2 through the delivery pump, and the temperature is 160°C, the pressure is 1Kpa, and the distillation is carried out with a reflux ratio of 1:1. The NMP is separated and recycled, and the heavy components at the bottom of the distillation kettle 2 are discharged into the recovery tank.

[0103] Example 2: Self-polymerization of cyclopentadiene

[0104] The products collected in Example 1 were placed at different temperatures (30°C / 20°C / 0°C / -5°C / -15°C / -25°C), and samples were taken at regular intervals (0h / 0.5h / 1h / 5h / 10h / 24h / 48h) for gas chromatography analysis. The decomposition rate (sample content / standard product content) was calculated. The results are shown in Table 2.

[0105] Table 1: Relationship between cyclopentadiene self-polymerization and time and temperature

[0106] 0 0.5h 1h 5h 10h 24h 48h 30℃ 0 22％ 45％ 60％ ＞95％ ＞95％ ＞95％ 20℃ 0 13％ 35％ 50％ ＞95％ ＞95％ ＞95％ 0℃ 0 8％ 13％ 20％ 23％ 25％ 25％ -5℃ 0 3％ 3％ 5％ 5.2％ 5％ 6％ -15℃ 0 1％ 1.5％ 1.8％ 2％ 2％ 2％ -25℃ 0 1％ 1.3％ 1.6％ 2％ 2％ 2％

[0107] It should be understood that the above embodiments are exemplary and are not intended to include all possible implementations included in the claims. Various modifications and changes may be made on the basis of the above embodiments without departing from the scope of the present disclosure. Similarly, the various technical features of the above embodiments may be arbitrarily combined to form other embodiments of the present invention that may not be explicitly described. Therefore, the above embodiments only express several implementations of the present invention and do not limit the scope of protection of the patent of the present invention.

Claims

1. A method for producing cyclopentadiene, characterized in that: The method comprises cracking dicyclopentadiene in the presence of methylpyrrolidone (NMP) to prepare the cyclopentadiene.

2. The method according to claim 1, characterized in that The method comprises the following steps: (1) using an inert gas to pressurize the preparation raw materials and diluent into a first reaction kettle, and heating and cracking them; (2) using a primary condenser to collect the gas phase components produced in step (1); (3) The product collected in step (2) is cooled by a secondary condenser and stored at low temperature.

3. The method according to claim 2, characterized in that The volume ratio of the inert gas to the raw material and the diluent in step (1) is 2:1 to 2:5; In step (1), the inert gas is nitrogen, the raw material is dicyclopentadiene, and the diluent is NMP; The heating in step (1) is heating to 170-200°C.

4. The method according to claim 2, characterized in that: The gas phase component in step (2) is a gas phase component at 41-44° C.; The reflux ratio of step (2) is 1:1 to 1:

5.

5. The method according to claim 2, characterized in that: The cooling in step (3) is cooling to 0-5°C; The low temperature storage in step (3) is storage at -5 to -10°C.

6. The method according to claim 2, characterized in that The method further comprises the steps of: (4) The residue in the first reactor is transferred into a second reactor for distillation to separate the diluent.

7. The method according to claim 6, characterized in that The reaction temperature of the distillation is 150-180°C, and the reaction pressure is 0.5-2Kpa; The reflux ratio of step (4) is 1:1 to 1:

3.

8. An apparatus for producing cyclopentadiene, characterized in that: The device comprises: A first distillation kettle (20) for heating dicyclopentadiene and NMP; a first distillation tower (24), the first distillation tower (24) being in communication with the first distillation kettle (20) to separate products from the first distillation kettle (20), the first distillation tower (24) being provided with a temperature sensor; A first collecting device, comprising a first primary condenser (30), a first secondary condenser (32) and a product tank (33), wherein the discharge port of the first rectification tower (24) is connected to the inlet of the first primary condenser (30), and the first secondary condenser (32) is connected between the first primary condenser (30) and the product tank (33), and is connected to the product tank (33); a secondary distillation device, connected to the first distillation kettle (20) to perform secondary distillation on the material flowing out of the first distillation kettle (20), wherein the secondary distillation device is provided with a temperature sensor; The second collecting device comprises a second primary condenser (50) and a second secondary condenser (52), wherein the discharge port of the secondary distillation device is connected to the inlet of the second primary condenser (50), and the second secondary condenser (52) is located downstream of the second primary condenser (50), and the outlet is connected to the solvent storage tank (13) to perform secondary condensation and recovery on the material.

9. The device according to claim 8, characterized in that The first collecting device further comprises a first reflux tank (31); The outlet of the first primary condenser (30) is communicated with the inlet of the first reflux tank (31), one outlet of the first reflux tank (31) is communicated with the inlet of the first secondary condenser (32), the other outlet of the first reflux tank is communicated with the first distillation tower (24), and the outlet of the first secondary condenser (32) is communicated with the product tank (33); The second collecting device further comprises a second reflux tank (51), the discharge port of the second distillation tower (43) is communicated with the inlet of the second primary condenser (50), the outlet of the second primary condenser (50) is communicated with the inlet of the second reflux tank (51), one outlet of the second reflux tank (51) is communicated with the second secondary condenser (52), and the other outlet of the second reflux tank (51) is communicated with the product tank (33); The secondary distillation device comprises a second distillation kettle (40) and a second distillation tower (43); the second distillation kettle (40) is connected to the first distillation kettle (20) and the second distillation tower (43) respectively to perform secondary distillation on the material flowing out of the first distillation kettle (20); the second distillation kettle (40) is also connected to a recovery tank (42); The temperature sensor is provided on the second distillation tower (43).

10. The device according to claim 9, characterized in that The fillers of the first distillation tower (24) and the second distillation tower (43) are high-purity PFA / PTFE rings with a diameter-to-height ratio of 1:5 to 1:

50.

11. The device according to claim 9, characterized in that The first distillation tower (24) and the second distillation tower (43) are divided into three sections, each of which is provided with a temperature sensor.

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