A dicyclopentadiene vapor phase depolymerization system and method

Abstract

The application discloses a dicyclopentadiene gas-phase depolymerization system and method, which can comprise a vaporizer, a cracking furnace in communication with the vaporizer, and a stripping column device in communication with the cracking furnace; the vaporizer is used for vaporizing dicyclopentadiene and water to obtain mixed steam; the cracking furnace is used for heating the mixed steam to make the dicyclopentadiene depolymerize to generate cyclopentadiene; and the stripping column device is used for extracting the cyclopentadiene after distillation and purification, and recycling uncracked dicyclopentadiene and water to the vaporizer for depolymerization. The dicyclopentadiene and water are vaporized and cracked under certain pressure and temperature, and the light and heavy components are separated at the same time; the water and unreacted dicyclopentadiene are filtered and recycled. The process is a green dicyclopentadiene depolymerization process, which is simple, has high depolymerization rate, and has the characteristics of less waste and the like.

Description

Technical Field

[0001] This invention relates to the field of petrochemical technology, and in particular to a dicyclopentadiene gas-phase depolymerization system and method. Background Technology

[0002] Cyclopentadiene is an important chemical industrial raw material with high chemical reactivity, capable of reacting with a variety of compounds. Simultaneously, cyclopentadiene readily self-polymerizes into dicyclopentadiene. Commercially available cyclopentadiene is sold in dimer form, and its use involves liquid-phase or gas-phase depolymerization to break it down into cyclopentadiene. Since the depolymerization rate of liquid-phase depolymerization is lower than that of gas-phase depolymerization, the commonly used process is gas-phase depolymerization. This involves heating the mixture to a high temperature of 330℃–350℃ using an inert gas (nitrogen or steam), followed by pyrolysis in a cracking reaction tower. The resulting gas is then distilled to obtain high-purity cyclopentadiene.

[0003] For example, in patent document CN1292369A, entitled "Preparation Method of High-Purity Cyclopentadiene," crude dicyclopentadiene is mixed with feed gas, preheated, and then instantaneously decomposed in a gas-phase depolymerization tower. The product is then separated and purified in a gas-phase depolymerization product fractionation tower. The upper part of this tower is a constant-temperature section, and the lower part is a rectification section. The separated and purified product is condensed to obtain high-purity cyclopentadiene. Summary of the Invention

[0004] The inventors discovered that, due to the high pyrolysis temperature of 350°C, preheating before the reaction is crucial. The aforementioned patent did not preheat the mixed gas, resulting in significant heat loss and consequently a reduced conversion rate. Furthermore, the method disclosed in the aforementioned patent easily leads to the formation of cyclopentadiene self-polymers adhering to the inner wall of the pyrolysis tower. Due to the tower's structure, these substances are difficult to clean, causing equipment blockage. The method disclosed in this patent uses a distillation column with rectification and stripping sections to separate the gas-phase pyrolysis products after pyrolysis. This distillation column also easily causes cyclopentadiene self-polymerization, thereby reducing the cyclopentadiene yield.

[0005] In view of the above problems, the present invention is proposed to provide a dicyclopentadiene gas-phase depolymerization system and method that overcomes or at least partially solves the above problems.

[0006] In a first aspect, embodiments of the present invention provide a dicyclopentadiene gas-phase depolymerization system, which may include: a vaporizer, a cracking furnace connected to the vaporizer, and a stripping tower device connected to the cracking furnace;

[0007] The vaporizer is used to vaporize dicyclopentadiene and water to obtain a vaporized mixture.

[0008] The pyrolysis furnace is used to heat the mixed steam to depolymerize the dicyclopentadiene into cyclopentadiene;

[0009] The stripping tower is used to extract the cyclopentadiene after distillation and purification, and to recover the unpyrolyzed dicyclopentadiene and water to the vaporizer for further depolymerization.

[0010] Optionally, the system may further include a reboiler in communication with the vaporizer; the reboiler is used to heat and vaporize the mixture of dicyclopentadiene and water.

[0011] Optionally, the heat transfer medium for the reboiler and the vaporizer includes at least one of the following: steam, heat transfer oil, and electric heating;

[0012] The heat transfer medium for the pyrolysis furnace includes at least one of the following: fuel gas, liquefied petroleum gas, fuel oil, and coal.

[0013] Optionally, the system may also include: a pressure control valve;

[0014] The pressure control valve is connected to the gas outlet of the vaporizer and the feed inlet of the pyrolysis furnace, respectively, and is used to regulate the pressure inside the vaporizer.

[0015] Optionally, the pressure control valve is an automatic control valve or a manual shut-off valve.

[0016] Optionally, at least one furnace tube is arranged from top to bottom inside the pyrolysis furnace;

[0017] The furnace tube serves as the mixing steam channel, used to receive heat from the external heat medium to depolymerize the dicyclopentadiene.

[0018] Optionally, the stripping tower device includes: a stripping tower, a top condenser, a reflux tank connected to the top condenser, and a reflux pump connected to the top condenser and the reflux tank respectively;

[0019] The stripping tower is used to separate and purify cyclopentadiene. The top of the tower yields cyclopentadiene, while the bottom contains water, a small amount of cyclopentadiene, and depolymerized dicyclopentadiene.

[0020] The top condenser is used to condense the mixed steam discharged from the stripping tower and discharge the condensate into the reflux tank.

[0021] The reflux tank is used to buffer and store the cyclopentadiene at the top of the tower;

[0022] The reflux pump is used to adjust the reflux ratio of the condensate.

[0023] Optionally, the system may further include a filter for filtering out colloidal substances and / or solid particles in the heavy components.

[0024] Optionally, the system may also include a circulation pump assembly for recovering unpyrolyzed dicyclopentadiene and water to the vaporizer after filtration through the filter.

[0025] Optionally, the system may further include: a preheater; the preheater is connected to both the vaporizer and the pyrolysis furnace;

[0026] The preheater is used to heat the mixed steam.

[0027] Secondly, embodiments of the present invention provide a method for the gas-phase depolymerization of dicyclopentadiene, which may include:

[0028] Dicyclopentadiene and water are mixed in a preset ratio and then heated and vaporized in a vaporizer to obtain a mixed vapor.

[0029] The mixed steam is reheated in the cracking furnace, and the dicyclopentadiene in the mixed steam depolymerizes to form cyclopentadiene.

[0030] The mixed vapor is separated and purified by a stripping tower to obtain cyclopentadiene.

[0031] Optionally, the method may further include: the mixed steam is preheated by a preheater and then discharged into the pyrolysis furnace for depolymerization.

[0032] Optionally, the method may further include: the undepolymerized dicyclopentadiene at the bottom of the stripping tower is discharged into the vaporizer for circulation treatment via a circulation pump group.

[0033] The beneficial effects of the above-mentioned technical solutions provided in the embodiments of the present invention include at least the following:

[0034] This invention provides a dicyclopentadiene gas-phase depolymerization system and method. The system may include: a vaporizer, a pyrolysis furnace connected to the vaporizer, and a stripping tower connected to the pyrolysis furnace. The vaporizer is used to vaporize dicyclopentadiene and water to obtain a vaporized mixed vapor. The pyrolysis furnace is used to heat the mixed vapor to depolymerize the dicyclopentadiene into cyclopentadiene. The stripping tower is used to purify and separate the cyclopentadiene, and the unreacted dicyclopentadiene and water at the bottom of the tower are recycled back to the vaporizer for further depolymerization. Dicyclopentadiene and water are vaporized and heated to pyrolysis under certain pressure and temperature, simultaneously achieving the separation of light and heavy components. Water and unreacted dicyclopentadiene are filtered and recycled. This process is a green dicyclopentadiene depolymerization process, characterized by its simplicity, high depolymerization rate, and low waste.

[0035] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings.

[0036] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0037] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0038] Figure 1 This is a schematic diagram of the structure of the dicyclopentadiene gas-phase depolymerization system provided in an embodiment of the present invention;

[0039] Figure 2 This is a schematic flowchart of the gas-phase depolymerization method for dicyclopentadiene provided in an embodiment of the present invention;

[0040] Among them, 1 is a vaporizer; 2 is a cracking furnace; 3 is a stripping tower; 4 is a reboiler; 5 is a pressure control valve; 6 is a filter; 7 is a circulating pump set; and 8 is a preheater. Detailed Implementation

[0041] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0042] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," "far," "near," "front," and "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0043] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0044] This invention provides a gas-phase depolymerization system for dicyclopentadiene, used to depolymerize dicyclopentadiene to obtain high-purity cyclopentadiene. (Refer to...) Figure 1 As shown, the system may include: a vaporizer 1, a cracking furnace 2 connected to the vaporizer 1, and a stripping tower device 3 connected to the cracking furnace 2; the vaporizer 1 is used to vaporize dicyclopentadiene and water to obtain a vaporized mixed gas; the cracking furnace 2 is used to heat the mixed gas to raise the temperature of the dicyclopentadiene and depolymerize it to generate cyclopentadiene; the stripping tower device 3 is used to extract cyclopentadiene after distillation and purification to obtain cyclopentadiene, and the uncracked dicyclopentadiene and water at the bottom of the tower are recovered to the vaporizer 1 for recycling and depolymerization.

[0045] The working principle of the above-mentioned dicyclopentadiene gas-phase depolymerization system in this embodiment of the invention is as follows: Dicyclopentadiene and water enter the vaporizer in a certain proportion and are vaporized in the vaporizer. The vaporized dicyclopentadiene and water vapor mixture enters the cracking furnace. Dicyclopentadiene is heated and cracked into cyclopentadiene in the cracking furnace. The cracked gas finally enters the bottom of the stripping tower. The mixed gas is separated in the stripping tower. The top of the tower contains light components containing cyclopentadiene, and the bottom of the tower contains heavy components such as water and dicyclopentadiene.

[0046] It should be noted that the vaporizer, pyrolysis furnace, and stripping tower in the above system of this invention are connected by pipelines, and valves can be installed at both the inlet and outlet to control the opening and closing of the pipelines. This invention does not impose specific limitations on this. It should also be noted that the ratio of dicyclopentadiene to water after vaporization can be adjusted according to the temperature of the mixed liquid in the vaporizer, or it can be adjusted in other ways. This invention does not impose specific limitations on this either.

[0047] The system provided in this embodiment of the invention vaporizes and heats water under certain pressure and temperature, and simultaneously separates light and heavy components. The water and unreacted dicyclopentadiene are filtered and recycled. This process is a green dicyclopentadiene depolymerization process with the characteristics of simple process, high depolymerization rate and less waste.

[0048] In an optional embodiment, the pyrolysis temperature of dicyclopentadiene needs to be above 350°C. If the vaporized mixture is directly heated in the pyrolysis furnace for pyrolysis, the pyrolysis rate will be low due to direct heating, resulting in a large amount of unpyrolyzed dicyclopentadiene needing to be recycled to participate in the reaction, thus reducing the overall reaction efficiency. See also... Figure 1 As shown, the system may further include: a reboiler 4 connected to the vaporizer 1; the reboiler 4 is used to heat and vaporize the mixture of dicyclopentadiene and water.

[0049] It should be noted that the reboiler described in the embodiments of the present invention can be a self-regulating thermal circulation reboiler. The heat source for the vaporizer is provided by the self-regulating thermal circulation reboiler, which can be steam, thermal oil, electric heater, etc. The mixed steam of dicyclopentadiene and water is heated by the vaporizer through a pipeline to the preheater. The vaporizer is a vertical pressure vessel, and the self-regulating thermal circulation reboiler can be one or a combination of a vertical fixed tube sheet heat exchanger, a horizontal floating head heat exchanger, or a horizontal fixed tube sheet heat exchanger.

[0050] In another alternative embodiment, reference is also made to Figure 1 As shown, the system may further include: a pressure control valve 5; the pressure control valve 5 is connected to the gas outlet of the vaporizer 1 and the feed inlet of the pyrolysis furnace 2 respectively, and is used to regulate the pressure of the vaporizer 1. It should be noted that the pressure control valve in this embodiment of the invention is a post-vaporizer control valve, used to control the vaporizer pressure.

[0051] In another optional embodiment, the pressure control valve described above is an automatic control valve or a manual shut-off valve. It should be noted that the vaporizer outlet pressure control valve can be an automatic control valve, a standard manual shut-off valve, or other types of valves; an automatic control valve is preferred.

[0052] In another optional embodiment, the pyrolysis furnace is a tubular heating furnace, which can be vertical, horizontal, or other types. The tubes contain a mixed gas of dicyclopentadiene and water. The mixed steam of dicyclopentadiene and water is heated within the furnace tubes, causing the dicyclopentadiene to crack. The furnace tubes can be single or multiple, each arranged from top to bottom. The arrangement of the furnace tubes can be coiled, serpentine, etc. The heating medium for the pyrolysis furnace can be fuel gas, liquefied petroleum gas (LPG), fuel oil, coal, etc. The dicyclopentadiene is heated and cracked within the furnace tubes, and the cracking products are components such as cyclopentadiene. The oil and gas within the pyrolysis furnace tubes are transported to the stripping tower via pipelines. At least one furnace tube is arranged from top to bottom within the pyrolysis furnace; the furnace tube serves as a mixed gas passage, used to receive heat from the external heating medium to depolymerize the dicyclopentadiene. It should be noted that the pipeline between the pyrolysis furnace and the stripping tower is part of the pyrolysis reaction, and the heating medium used in the pyrolysis furnace can be fuel gas, LPG, fuel oil, coal, etc.

[0053] The inventors discovered that with prolonged operation, carbon accumulates inside the pyrolysis furnace tubes, and the tubes may even become blocked. The degree of blockage can be determined by the pressure difference between the inlet and outlet of the furnace tubes. When the carbon accumulation in the furnace tubes reaches a certain level, the operation is stopped, the medium inside the furnace tubes is changed to a mixture of water vapor and air, and the temperature is increased. The carbon is burned off according to a certain procedure, which can remove the carbon accumulation inside the furnace tubes. After the carbon accumulation is removed, the pyrolysis furnace can be put into normal operation.

[0054] This invention focuses on solving the problem of heating raw material mixed steam and achieving pyrolysis simultaneously using a shell-and-tube heating furnace. The pyrolysis gas achieves separation of light and heavy components in the stripping tower, and the carbon deposits in the furnace tubes can be treated by sintering, thus solving the problem of clogging in the pyrolysis equipment.

[0055] In another alternative embodiment, the stripping tower internal apparatus may include: a stripping tower, a top condenser, a reflux tank connected to the top condenser, and a reflux pump connected to the top condenser and the reflux tank respectively.

[0056] The stripping tower is used to separate and purify cyclopentadiene. The top of the tower yields cyclopentadiene, while the bottom contains water, a small amount of cyclopentadiene, and pyrolyzed dicyclopentadiene.

[0057] The top condenser is used to condense the mixed steam discharged from the stripping tower and discharge the condensate into the reflux tank;

[0058] The reflux tank is used for buffer storage of cyclopentadiene;

[0059] A reflux pump is used to adjust the reflux ratio of the condensate.

[0060] The heat source for the stripping tower is the heat carried by the cracked gas itself. The stripping tower unit includes a fractionation tower system consisting of a stripping tower, a top condenser, a top reflux tank, a top reflux pump, and a bottom pump. The top of the stripping tower contains light components rich in cyclopentadiene, while the bottom contains water, dicyclopentadiene, and other heavy components. The bottom material is recycled to the vaporizer after passing through the bottom pump and filter.

[0061] The stripping tower apparatus provided in this embodiment of the invention includes: a stripping tower, a top condenser / cooler, a reflux tank, and a bottom pump. High-temperature pyrolysis gas from the pyrolysis furnace serves as the raw material for the stripping tower and also as the heat source for the bottom of the tower. The oil and gas at the top of the tower are liquefied by the condenser / cooler and then sent to the top reflux tank. After being pumped back by the reflux pump, part of the gas is refluxed, and part is output as cyclopentadiene product. The top of the stripping tower contains light components rich in cyclopentadiene, while the bottom contains water, dicyclopentadiene, and other heavy components. The heavy components at the bottom are pumped back by the bottom pump, filtered through a filter to remove the viscous liquid and other heavy components, and then recycled back to the vaporizer for further processing. The stripping tower can be a plate tower or a packed tower.

[0062] In another alternative embodiment, refer to Figure 1As shown, the system may further include: a filter 6; the filter 6 is used to filter out colloidal substances and / or solid particles in the heavy components.

[0063] In another alternative embodiment, refer to Figure 1 As shown, the system may also include: a circulation pump group 7, which is used to recover uncracked dicyclopentadiene and water to the vaporizer 1 after filtration through the filter 6.

[0064] In an optional embodiment, refer to Figure 1 As shown, the system may further include: a preheater 8; the preheater 8 is connected to the vaporizer 1 and the pyrolysis furnace 2 respectively;

[0065] The preheater 8 is used to heat the mixed steam.

[0066] In this embodiment of the invention, the mixed steam in the vaporizer is preheated, causing it to rapidly reach the pyrolysis temperature before entering the pyrolysis furnace. This significantly improves the pyrolysis efficiency, reduces the dicyclopentadiene content in the stripping tower, and saves on recycling costs. The heat medium in the preheater in this embodiment can be steam, heat transfer oil, electric heating, etc., and this embodiment does not specifically limit its use.

[0067] The system described in this embodiment of the invention realizes the vaporization, preheating, and thermal cracking of dicyclopentadiene and water under certain pressure and temperature, while simultaneously separating light and heavy components. Water and unreacted dicyclopentadiene are filtered and recycled. This process is a green dicyclopentadiene depolymerization process with the characteristics of simple process, high depolymerization rate, and less waste.

[0068] Based on the same inventive concept, this invention also provides a method for the gas-phase depolymerization of dicyclopentadiene, referring to... Figure 2 As shown, the method may include:

[0069] Step S21: Dicyclopentadiene and water are mixed in a preset ratio and then heated and vaporized in a vaporizer to obtain a mixed vapor.

[0070] Step S22: The mixed steam is reheated in the cracking furnace, and the dicyclopentadiene in the mixed steam depolymerizes to form cyclopentadiene.

[0071] Step S23: The mixed steam is distilled and purified by a stripping tower to obtain cyclopentadiene.

[0072] In an optional embodiment, reference is also made to Figure 2 As shown, the method may further include:

[0073] Step S24: After the mixed steam is preheated by the preheater, it is discharged into the cracking furnace for depolymerization.

[0074] In an optional embodiment, reference is also made to Figure 2 As shown, the method may further include:

[0075] Step S25: Undepolymerized dicyclopentadiene in the mixed vapor is discharged into the vaporizer for recycling.

[0076] The process description of the dicyclopentadiene gas-phase depolymerization method provided by this invention is as follows: Dicyclopentadiene and water enter a vaporizer through a pipeline. Within the vaporizer, vaporization is carried out at a specific ratio by adjusting the temperature. The heat of vaporization is provided by a self-regulating thermal reboiler, whose heating medium can be steam, heat transfer oil, an electric heater, etc. A pressure control valve is installed at the vaporizer outlet; this valve can be manual or automatic, optimized as an automatic control valve. The mixed steam of dicyclopentadiene and water is heated in a cracking furnace, while simultaneously, dicyclopentadiene is cracked into cyclopentadiene. The cracked gas then passes through… The gas is transported through pipelines to the stripping tower. The heating medium for the pyrolysis furnace can be fuel gas, liquefied petroleum gas, fuel oil, or coal. The pyrolysis gas from the pyrolysis furnace is fed directly into the stripping tower and also serves as the heat source for the stripping tower bottom. The stripping tower assembly consists of a stripping tower, a top condenser, a reflux tank, a reflux pump, and a bottom pump. The top of the tower contains cyclopentadiene, which is output as the product. The bottom of the tower contains water, dicyclopentadiene, and other heavy components. The bottom material is pumped to a filter by the bottom pump to remove colloidal and solid particles. The liquid phase is returned to the vaporizer for recycling through pipelines.

[0077] The specific implementation and detailed description of the above methods in the embodiments of the present invention can be referred to the relevant description of the above dicyclopentadiene gas-phase depolymerization system, and repeated parts will not be repeated.

[0078] The technical solution of the present invention will be described in detail below through specific embodiments.

[0079] Example 1 (This case is a chemical process simulation case)

[0080] 1000 kg / h of 85% polyester-grade dicyclopentadiene and 300 kg / h of condensate enter the vaporizer through pipelines. The vaporizer temperature and the vaporization ratio of dicyclopentadiene and water are controlled by adjusting the vaporizer temperature. At this point, the temperature is 149.7℃, the mixed gas pressure is 150 kPa(A), and the reboiler heating medium is 1.0 MPa steam. A 1300 kg / h mixture of dicyclopentadiene and water is produced. A pressure control valve is installed at the vaporizer outlet, controlling the vaporizer pressure to 130 kPa (absolute pressure). The mixed gas in the vaporizer is then transported to the cracking furnace through pipelines. The cracking furnace is a vertical cylindrical furnace. The aforementioned oil and gas mixture is processed in the cracking furnace... The internal temperature is raised to 350℃, and 99% of the dicyclopentadiene is cracked into cyclopentadiene. The cracking furnace has four sets of coiled tubes, with four feed inlets and four pyrolysis gas outlets. The heating medium for the cracking furnace is natural gas. The pyrolysis gas is transported to the stripping tower via pipeline. The stripping tower has a reflux ratio of 1.5. The top of the tower contains cyclopentadiene, while the bottom contains water, trace amounts of dicyclopentadiene, and heavy components. The top temperature is 42℃, and the bottom temperature is 65℃. The top pressure is close to atmospheric pressure. The stripping tower is a perforated plate corrugated packing tower. The bottom material of the stripping tower is pumped to a filter. After the bottom material is filtered to remove the gum and solid impurities, it is returned to the vaporizer for recycling. In this case, the dicyclopentadiene cracking rate is 99%, the dicyclopentadiene content at the top of the stripping tower is 0.01% wt, and the cyclopentadiene content at the bottom of the stripping tower is 0.01% wt.

[0081] Example 2 (This case is a chemical process simulation case)

[0082] 1000 kg / h of 95% polyester-grade dicyclopentadiene and 200 kg / h of condensate enter the vaporizer through pipelines. The vaporizer temperature and the vaporization ratio of dicyclopentadiene and water are controlled by adjusting the vaporizer temperature to 153°C. The reboiler heating medium is 1.0 MPa steam. A pressure control valve is installed at the vaporizer outlet, and the vaporizer pressure is controlled at 130 kPa (absolute pressure). The mixed steam of dicyclopentadiene and water is transported to the cracking furnace through pipelines. The cracking furnace is a vertical cylindrical furnace. The above oil and gas are heated to 350°C in the cracking furnace, and 99% of the dicyclopentadiene is cracked. The cracking process yields dicyclopentadiene. The cracking furnace has four sets of coiled tubes, with four feed inlets and four pyrolysis gas outlets. Natural gas is used as the heating medium. The pyrolysis gas is piped to a stripping tower with a reflux ratio of 1.25. The top of the tower contains dicyclopentadiene, while the bottom contains water, trace amounts of dicyclopentadiene, and heavy components. The top temperature is 42°C, and the bottom temperature is 65°C. The top pressure is close to atmospheric pressure. The stripping tower is a perforated plate corrugated packing tower. The bottom material is pumped to a filter, where it is filtered to remove gum and solid impurities before being returned to the vaporizer for recycling. In this case, the dicyclopentadiene cracking rate is 99%, and the dicyclopentadiene content at the top and bottom of the stripping tower is 0.01% wt.

[0083] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. This disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims. Thus, if these modifications and variations of the invention fall within the scope of the claims of the invention and their equivalents, the invention is also intended to include these modifications and variations.

Claims

1. A dicyclopentadiene gas-phase depolymerization system, characterized in that, include: A vaporizer, a pyrolysis furnace connected to the vaporizer, a stripping tower connected to the pyrolysis furnace, a reboiler connected to the vaporizer, a pressure control valve, and a preheater. The vaporizer is used to vaporize dicyclopentadiene and water to obtain a vaporized mixture. The reboiler is a self-regulating thermal circulation reboiler, used to heat and vaporize the mixture of dicyclopentadiene and water. The preheater is connected to both the vaporizer and the pyrolysis furnace, and is used to heat the mixed steam. The pyrolysis furnace is a tubular heating furnace, and at least one furnace tube is arranged from top to bottom inside the pyrolysis furnace. The furnace tube is a channel for the mixed steam and is used to receive heat from the external heat medium. The pyrolysis furnace is used to heat the mixed steam to depolymerize the dicyclopentadiene into cyclopentadiene. The pressure control valve is connected to the gas outlet of the vaporizer and the feed inlet of the pyrolysis furnace, respectively, and is used to regulate the pressure inside the vaporizer to be positive. The high-temperature pyrolysis gas from the pyrolysis furnace is used as the raw material for the stripping tower device and also as the heat source at the bottom of the stripping tower device. The stripping tower device is used to extract the cyclopentadiene after distillation and purification, and to recover the unpyrolyzed dicyclopentadiene and water to the vaporizer for recycling and depolymerization.

2. The system according to claim 1, characterized in that, The heat transfer medium for the reboiler and the vaporizer includes at least one of the following: steam, heat transfer oil, and electric heating. The heat transfer medium for the pyrolysis furnace includes at least one of the following: fuel gas, liquefied petroleum gas, fuel oil, and coal.

3. The system according to claim 1, characterized in that, The pressure control valve is either an automatic control valve or a manual shut-off valve.

4. The system according to claim 1, characterized in that, The stripping tower device includes: a stripping tower, a top condenser, a reflux tank connected to the top condenser, and a reflux pump connected to the top condenser and the reflux tank respectively. The stripping tower is used to purify and separate cyclopentadiene; The top condenser is used to condense the mixed steam discharged from the stripping tower and discharge the condensate into the reflux tank. The reflux tank is used to buffer and store the cyclopentadiene at the top of the tower; The reflux pump is used to adjust the reflux ratio of the condensate.

5. The system according to any one of claims 1 to 4, characterized in that, Also includes: Filter; The filter is used to filter out colloidal substances and / or solid particulate matter in the heavy components.

6. The system according to claim 5, characterized in that, Also includes: A circulating pump assembly is used to recover unpyrolyzed dicyclopentadiene and water into the vaporizer after filtration through the filter.

7. A method for the gas-phase depolymerization of dicyclopentadiene, characterized in that, The dicyclopentadiene gas-phase depolymerization system according to any one of claims 1 to 6 comprises: Dicyclopentadiene and water are mixed in a preset ratio and then heated and vaporized in a vaporizer to obtain a mixed vapor. The mixed steam is reheated in the cracking furnace, and the dicyclopentadiene in the mixed steam depolymerizes to form cyclopentadiene. The mixed vapor is separated and purified by a stripping tower to obtain cyclopentadiene.

8. The method according to claim 7, characterized in that, Also includes: The mixed steam is preheated by a preheater and then discharged into the pyrolysis furnace for depolymerization.

9. The method according to claim 8, characterized in that, Also includes: Undepolymerized dicyclopentadiene and water at the bottom of the stripping tower are recycled back to the vaporizer for further processing via a circulating pump system.

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