Device for refining cyclopentadiene by depolymerizing dicyclopentadiene with gas as diluent

Abstract

The utility model belongs to the application field of chemistry, chemical engineering and environmental science, and discloses a device for refining cyclopentadiene by depolymerizing dicyclopentadiene by taking gas as a diluent. Comprising a raw material storage tank, a feeding pump, an evaporator, a heater, a gas preheater, a first cracker, a second cracker, a reboiler, a first rectifying tower, a second rectifying tower, a reboiler, a first condenser, a receiving tank, a product storage tank, a second condenser and a gas compressor. Raw materials enter the preheating pipe and the evaporator through the feeding pump to be preheated and evaporated, and then are mixed and heated with bypass carrier gas in the heater, depolymerized through the secondary cracker and rectified. After being preheated, the raw materials are mixed and diluted with the other path of gas, so that coking in the subsequent high-temperature cracking process is effectively inhibited, and meanwhile, the rate of the subsequent cracking reaction and the concentration of the raw materials are effectively controlled; through multiple cracking, the cracking efficiency is effectively improved; and the purity of the cyclopentadiene is effectively improved to 98% or above through separation of the double rectifying towers.

Description

Technical Field

[0001] The utility model belongs to the fields of teaching, scientific research and industrial production applications in the majors of chemistry, chemical engineering and environmental science, and relates to a device for depolymerizing and refining cyclopentadiene from dicyclopentadiene with gas as a diluent. Background Technique

[0002] Dicyclopentadiene (abbreviated as DCPD) is a by-product of ethylene production by petroleum cracking and a light benzene fraction by-produced from coal coking. In the actual application process, the methods for preparing cyclopentadiene (CPD) by cracking dicyclopentadiene DCPD mainly include low-temperature liquid-phase depolymerization method, high-temperature liquid-phase depolymerization method and high-temperature gas-phase depolymerization method. The low-temperature liquid-phase depolymerization method adopts batch operation, and the operation temperature is controlled below 200°C. The main advantages are simple equipment and short process route. The disadvantages are slow depolymerization speed and low product yield. The high-temperature liquid-phase depolymerization process uses an organic heat carrier for continuous operation, and the operation temperature is 200°C - 300°C. The raw materials are quickly dispersed by the heat carrier in the kettle, generating more poly-polymers, and the reaction proceeds in the forward direction by continuously removing the product CPD from the system. The product yield is greatly improved compared with low-temperature depolymerization. The advantages are simple equipment, short process route and high efficiency. The disadvantages are that the heavy components in the raw materials contact the high-temperature organic carrier for a long time, generating more polymers, deteriorating the carrier, and blocking the reactor. The high-temperature gas-phase depolymerization method adopts continuous operation, and the operation temperature is generally above 300°C. The vaporized DCPD is heated to the reaction temperature in a very short time, causing DCPD to crack instantly. The advantages are fast depolymerization speed and high yield. The disadvantages are complex equipment, easy to coke at high temperature during operation, and difficult to operate for a long time.

[0003] The high-temperature gas-phase depolymerization method is the most commonly used method for refining cyclopentadiene. Therefore, it is of great significance to design and develop a new device with good cracking performance and high purification performance to improve the purity of cyclopentadiene, reduce the complexity of the equipment and reduce coking, etc. In addition, this new depolymerization device can also be applied to the teaching and scientific research of undergraduates and postgraduates. Summary of the Utility Model

[0004] The purpose of the utility model is to solve the deficiencies existing in the prior art, and provide a device for depolymerizing and refining cyclopentadiene from dicyclopentadiene with high depolymerization efficiency, low complexity of the equipment, not easy to appear coking and blocking phenomena, and improving the purity of the product, greatly improving the recovery rate and purity of the product.

[0005] The technical solution of the utility model:

[0006] A dicyclopentadiene depolymerization and refining cyclopentadiene device using gas as a diluent, comprising a raw material storage tank 1, a feed pump 2, an evaporator 3, a heater 4, a gas preheater 5, a first cracker 6, a second cracker 7, a reboiler 8, a first distillation column 9, a second distillation column 10, a reboiler 11, a first condenser 12, a receiving tank 13, a product storage tank 14, a second condenser 15 and a gas compressor 16;

[0007] The discharge port at the bottom of the raw material storage tank 1 is connected to the inlet at the upper side of the evaporator 3 through a pipeline via the feed pump 2. The outlet at the top of the evaporator 3 is connected to the inlet at the bottom of the heater 4 through a pipeline. The inlet at the lower side of the heater 4 is connected to the outlet at the top of the gas preheater 5. The inlet at the lower side of the gas preheater 5 is connected to the outlet at the top of the receiving tank 13, and the bottom of the gas preheater 5 is provided with an inlet. The outlet at the upper side of the heater 4 is connected to the inlet at the bottom of the first cracker 6 through a pipeline. The outlet at the top of the first cracker 6 is connected to the inlet at the top of the second cracker 7 through a pipeline. The bottom outlet of the second cracker 7 is connected to the middle inlet of the first distillation column 9 through a pipeline. Meanwhile, a liquid receiving valve is installed on this pipeline. The outlet at the top of the first distillation column 9 is connected to the middle inlet of the second distillation column 10 through a pipeline. The outlet at the top of the second distillation column 10 is connected to the inlet of the first condenser 12. The outlet of the first condenser 12 is connected to the inlet of the receiving tank 13 through a pipeline. The outlet at the bottom of the first distillation column 9 is connected to the right-end outlet of the reboiler 8 through a pipeline. The left-end outlet of the reboiler 8 is connected to the inlet at the top of the raw material storage tank 1. The inlet at the lower side of the first distillation column 9 is connected to the top outlet of the reboiler 8. The outlet at the bottom of the second distillation column 10 is connected to the inlet at the right end of the reboiler 11 through a pipeline. The lower outlet of the reboiler 11 is connected to the inlet of the second condenser 15. The outlet of the second condenser 15 is connected to the inlet of the product storage tank 14 through a pipeline. The outlet of the product storage tank 14 is connected to the outlet at the bottom of the receiving tank 13. The inlet at the lower side of the second distillation column 10 is connected to the top outlet of the reboiler 11 through a pipeline. The inlet at the upper side of the second distillation column 10 is connected to the outlet at the bottom of the receiving tank 13 through a pipeline and the feed pump 2.

[0008] Heat preservation tapes are wound outside the pipelines between the raw material storage tank 1 and the feed pump 2, between the feed pump 2 and the evaporator 3, between the heater 4 and the first cracker 6, between the first cracker 6 and the second cracker 7, and between the second cracker 7 and the first distillation column 9. A heat preservation layer is provided outside the raw material storage tank 1. A pipeline heat preservation layer is provided on the pipeline, which is a heating wire heat preservation tape wound on the pipeline. A tank body heat preservation layer is provided outside the raw material storage tank 1, which is an electric heating sleeve for heat preservation.

[0009] A switchable ball valve is provided at the bottom end of the evaporator 3.

[0010] Multiple baffle plates are provided in the middle of the first cracker 6 and the second cracker 7 to effectively control the cracking flow rate.

[0011] A gas flowmeter is installed in the pipeline between the preheater 5 and the heater 4 to facilitate recording the gas flow rate.

[0012] The bottom end of the second cracker 7 is equipped with a switchable ball valve for sampling at any time.

[0013] The first distillation column 9 and the second distillation column 10 include a rectifying section, a cooling section provided at the top of the rectifying section, and a heat preservation layer for the cooling section tank body. The heat preservation layer for the tank body is a rock wool board laid flat on the outer surface of the cooling section.

[0014] The condenser is cooled by heat exchange through a coiled pipe.

[0015] This device uses a gas as a diluent and increases the gas recycling technology to achieve the purpose of resource recycling.

[0016] This device effectively extends the cracking time and increases the number of baffle plates by increasing the number of crackers, improves the depolymerization efficiency, thereby increasing the yield of the cracking products and simplifying the complexity of the equipment.

[0017] The outer surface of the raw material storage tank is equipped with an electric heating jacket device, reducing mixing devices such as mechanical stirring tanks and lowering the complexity of the device.

[0018] By increasing the number of distillation columns and performing multiple distillation operations, the purity of cyclopentadiene is improved.

[0019] By using the bypass gas as a carrier gas, the flow rate of the diluent can be effectively controlled, the dilution concentration of the product can be effectively regulated, the polymerization of the product can be reduced, coking can be reduced, and the purpose of simplicity, safety and high efficiency can be achieved in industrial production.

[0020] In teaching, students can also master the compound cracking and distillation operation skills, and in scientific research, the separation and purification of compounds can be realized.

[0021] The beneficial effects of the present utility model: The length of the cracker is extended and the number of baffle plates is increased, the depolymerization efficiency is higher, the number of crackers is reduced, and the equipment is simplified. Using a gas as a diluent effectively inhibits the occurrence of coking during the high-temperature cracking process, and at the same time, the rate of the subsequent cracking reaction and the concentration of the raw material can be controlled; multiple distillations are carried out, and the purity of the product is higher. Description of the Drawings

[0022] Figure 1 It is a structural schematic diagram of the present utility model.

[0023] In the figure: 1 raw material storage tank; 2 feed pump; 3 evaporator; 4 heater; 5 gas preheater; 6 first cracker; 7 second cracker; 8 reboiler; 9 first distillation column; 10 second distillation column; 11 reboiler; 12 first condenser; 13 receiving tank; 14 product storage tank; 15 second condenser; 16 gas compressor. Detailed implementation manners

[0024] The following further describes the detailed implementation manners of the present utility model in conjunction with the accompanying drawings and technical solutions.

[0025] As Figure 1 shown, a dicyclopentadiene depolymerization and purification cyclopentadiene device using a gas as a diluent includes a raw material storage tank 1, a feed pump 2, an evaporator 3, a heater 4, a gas preheater 5, a first cracker 6, a second cracker 7, a reboiler 8, a first distillation column 9, a second distillation column 10, a reboiler 11, a first condenser 12, a receiving tank 13, a product storage tank 14, a second condenser 15, and a gas compressor 16;

[0026] A feed pump 2 is connected between the raw material storage tank 1 and the evaporator 3. Before the raw material enters the top of the evaporator 3 through the feed pump 2, all instrument components are preset with corresponding temperatures. After the raw material enters the evaporator, it evaporates directly. At the same time, the gas diluent enters the heater 4 through the gas preheater 5. After being heated in the heater 4, the mixed gas enters the first cracker 6 and the second cracker 7 through the outlet end of the heater 4 for cracking. The cracked products directly enter the first distillation column 9. The low-boiling compounds enter the second distillation column 10 through the rectifying section and the condensing section. The high-boiling compounds and dicyclopentadiene raw materials, etc., return to the raw material tank 1 for continuous cyclic cracking. The products entering the second distillation column 10 are purified by distillation to obtain high-purity cyclopentadiene products, which enter the receiving tank 13 after being cooled by the condenser. A feed pump is added between the receiving tank 13 and the second distillation column 10 to further cyclically purify the purity of the products in the receiving tank.

[0027] The gas diluent enters through the bottom of the gas preheater 5, is preheated, and then enters from the lower side of the heater 4 to be mixed and heated with the raw material gas. It successively passes through the first cracker 6, the second cracker 7, and then enters the first distillation column 9, the second distillation column 10, then enters the receiving tank 13, and returns to the gas preheater 5 through the top outlet of the receiving tank 13 and the gas compressor 16 for recycling.

[0028] In the description of the present utility model, the orientation or positional relationship indicated by the terms "inside", "outside", "above", "below", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and does not require the present utility model to be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model.

[0029] As described above, it is only a specific embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any person skilled in the art within the technical scope described by the present utility model, according to the technical solution of the present utility model and its inventive concept, making equivalent substitutions or changes, shall be covered by the protection scope of the present utility model.

Claims

1. A device for refining cyclopentadiene by depolymerizing dicyclopentadiene using gas as diluent, characterized in that: The dicyclopentadiene depolymerization and purification cyclopentadiene device comprises a raw material storage tank (1), a feed pump (2), an evaporator (3), a heater (4), a gas preheater (5), a first cracker (6), a second cracker (7), a reboiler (8), a first distillation tower (9), a second distillation tower (10), a reboiler (11), a first condenser (12), a receiving tank (13), a product storage tank (14), a second condenser (15) and a gas compressor (16); The discharge port at the bottom of the raw material storage tank (1) is connected to the inlet at the upper part of the evaporator (3) through a pipeline through a feed pump (2), the outlet at the top of the evaporator (3) is connected to the inlet at the bottom of the heater (4) through a pipeline, the inlet at the lower part of the heater (4) is connected to the outlet at the top of the gas preheater (5), the inlet at the lower part of the gas preheater (5) is connected to the outlet at the top of the receiving tank (13), and the gas preheater (5) is provided with an inlet at the bottom; the outlet at the upper part of the heater (4) is connected to the inlet at the bottom of the first cracker (6) through a pipeline, the outlet at the top of the first cracker (6) is connected to the inlet at the top of the second cracker (7) through a pipeline; the outlet at the bottom of the second cracker (7) is connected to the middle inlet of the first distillation tower (9) through a pipeline, and a liquid receiving valve is installed on the pipeline; the outlet at the top of the first distillation tower (9) is connected to the middle inlet of the second distillation tower (10) through a pipeline, and the outlet at the top of the second distillation tower (10) is connected to the outlet at the top of the first condenser (12 ), the outlet of the first condenser (12) is connected to the inlet of the receiving tank (13) through a pipeline; the outlet at the bottom of the first distillation tower (9) is connected to the right end outlet of the reboiler (8) through a pipeline, the left end outlet of the reboiler (8) is connected to the inlet at the top of the raw material storage tank (1), and the inlet of the lower side of the first distillation tower (9) is connected to the outlet at the top of the reboiler (8); the outlet at the bottom of the second distillation tower (10) is connected to the right end inlet of the reboiler (11) through a pipeline The outlet at the lower end of the reboiler (11) is connected to the inlet of the second condenser (15), the outlet of the second condenser (15) is connected to the inlet of the product storage tank (14) through a pipeline, and the outlet of the product storage tank (14) is connected to the outlet at the bottom of the receiving tank (13); the lower inlet on the side of the second distillation tower (10) is connected to the outlet at the top of the reboiler (11) through a pipeline; the upper inlet on the side of the second distillation tower (10) is connected to the outlet at the bottom of the receiving tank (13) through a pipeline and a feed pump (2).

2. The device for refining cyclopentadiene by depolymerization of dicyclopentadiene using gas as diluent according to claim 1, characterized in that: The pipelines between the raw material storage tank (1) and the feed pump (2), between the feed pump (2) and the evaporator (3), between the heater (4) and the first cracker (6), between the first cracker (6) and the second cracker (7), and between the second cracker (7) and the first distillation tower (9) are all wrapped with heating tape for thermal insulation; the outer layer of the raw material storage tank (1) is provided with a heating and thermal insulation layer.

3. The device for refining cyclopentadiene by depolymerization of dicyclopentadiene using gas as diluent according to claim 2, characterized in that: The pipeline is provided with a pipeline insulation layer, which is a heating wire insulation belt wound around the pipeline; the outer layer of the raw material storage tank (1) is provided with a tank body insulation layer, which is an electric heating sleeve for heating and heat preservation.

4. The device for refining cyclopentadiene by depolymerization of dicyclopentadiene using gas as diluent according to claim 1, characterized in that: A switchable ball valve is arranged at the bottom end of the evaporator (3).

5. The device for refining cyclopentadiene by depolymerization of dicyclopentadiene using gas as diluent according to claim 1, characterized in that: A plurality of baffles are provided between the first cracker (6) and the second cracker (7) to effectively control the flow rate of cracking.

6. The device for refining cyclopentadiene by depolymerization of dicyclopentadiene using gas as diluent according to claim 1, characterized in that: The pipeline between the preheater (5) and the heater (4) is provided with a gas flow meter to facilitate recording of the gas flow.

7. The device for refining cyclopentadiene by depolymerization of dicyclopentadiene using gas as diluent according to claim 1, characterized in that: The bottom end of the second cracker (7) is provided with a switchable ball valve for sampling at any time.

8. The device for refining cyclopentadiene by depolymerization of dicyclopentadiene using gas as diluent according to claim 1, characterized in that: The first distillation tower (9) and the second distillation tower (10) comprise a distillation section, a cooling section arranged at the top of the distillation section, and a cooling section tank insulation layer.

9. The device for refining cyclopentadiene by depolymerization of dicyclopentadiene using gas as diluent according to claim 8, characterized in that: The tank insulation layer is a rock wool board laid evenly on the outer surface of the cooling section.

10. The device for refining cyclopentadiene by depolymerization of dicyclopentadiene using gas as diluent according to claim 1, characterized in that: The condenser is cooled by coil heat exchange.

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