Method and system for separating dicyclopentadiene dioxide from mixture

Abstract

The invention discloses a method and system for separating dicyclopentadiene dioxide from a mixture, and the method comprises the following steps: introducing a third component into the mixture to form a multi-component material flow, and enabling the multi-component material flow to sequentially enter a first rectifying tower and a second rectifying tower which are connected in series for separation to obtain dicyclopentadiene dioxide. Wherein the boiling point of the light component is far lower than the boiling point of the heavy component, the light component and the heavy component cannot be effectively separated through one-time flash evaporation, and the boiling point of the third component is higher than the boiling point of the light component and lower than the boiling point of the heavy component. A third component with the boiling point between a light component and a heavy component is creatively added into a mixture raw material, the mixed multi-component material flow is introduced into a first rectifying tower, the light component and the third component are extracted from the tower top, and the third component and the heavy component are extracted from a tower kettle and are introduced into a second rectifying tower; a third component is mainly extracted from the top of the second rectifying tower, and heavy components such as dicyclopentadiene dioxide and the like are mainly extracted from a tower kettle.

Description

Technical Field

[0001] The invention belongs to the field of mixture separation, and in particular relates to a method and a system for separating dicyclopentadiene dioxide from a mixture. Background Art

[0002] my country is currently the world's largest producer and consumer of epoxy resins. Most of the products produced are ordinary bisphenol-I epoxy resins (accounting for about 80% of the total), and high-end special epoxy resins are mainly imported. In developed countries, the consumption ratio of ordinary epoxy resins to special epoxy resins has reached 5:5, while the current situation in China is that ordinary epoxy resins have an overcapacity and special epoxy resin products are in serious shortage, and they are in urgent need of development and production.

[0003] Dicyclopentadiene dioxide (DCPDDO) is an important alicyclic special epoxy resin with excellent heat resistance, weather resistance, electrical insulation and high hardness. It has good market prospects and application value in China and has great development potential. In recent years, the green epoxidation process using organic peroxide as oxygen source and titanium silicon molecular sieve as catalyst has received widespread attention.

[0004] CN113087717A discloses a method for preparing dicyclopentadiene dioxide and alkylene oxide by using titanium silicon molecular sieve catalyst. The reaction product containing dicyclopentadiene dioxide is subjected to conventional distillation, with a reflux ratio of 3 to 10:1, a tower bottom temperature of 50 to 140°C, and a tower top temperature of 20 to 100°C. An alkylene oxide product with a purity of 60% to 99% is obtained at the tower top, and a dicyclopentadiene dioxide product with a purity of 50% to 85% is obtained at the tower bottom.

[0005] The inventors have found that when using a conventional distillation method to separate and purify products containing dicyclopentadiene dioxide, there are problems such as easy scaling of the conventional reboiler, carbonization of the product, and easy clogging and damage of the conventional reboiled liquid delivery pump, which makes it difficult to achieve continuous and stable operation of the conventional distillation because dicyclopentadiene dioxide belongs to a heat-sensitive system. Therefore, it is necessary to adopt technologies such as a scraped evaporator, a falling film evaporator, and a solid-liquid delivery pump with a reboiler form of a once-through type.

[0006] However, since the mixture product containing dicyclopentadiene dioxide has the characteristics of a wide distillation range and a high content of light components, the existing technology using scraped-plane evaporator / falling-film evaporator also has problems such as too high reboil vaporization rate and too low tower top condensation temperature.

[0007] Examples of the light components in the mixture containing dicyclopentadiene dioxide include cyclohexane, cyclohexene, benzene, and the like, and examples of the heavy components include 1-phenylethanol, α,α-dimethylbenzyl alcohol, dicyclopentadiene dioxide, and the like. Summary of the invention

[0008] The conventional distillation in the prior art has problems such as easy scaling of the reboiler, pump clogging, product carbonization, etc., and the use of a scraper / falling film evaporator has problems such as too high a vaporization rate and too low a tower top condensation temperature. In order to overcome the problems existing in the prior art, the present invention provides a method and system for separating dicyclopentadiene dioxide from a mixture, wherein the present invention innovatively proposes adding a third component having a boiling point between the light component and the heavy component to the mixture raw material, and then sequentially introducing the third component into a first distillation tower and a second distillation tower to finally obtain dicyclopentadiene dioxide.

[0009] One of the objects of the present invention is to provide a method for separating dicyclopentadiene dioxide from a mixture, wherein the mixture contains a light component and a heavy component containing dicyclopentadiene dioxide, and the method comprises: introducing a third component into the mixture to form a multi-component stream, and the multi-component stream then sequentially enters a first distillation tower and a second distillation tower connected in series for separation to obtain dicyclopentadiene dioxide.

[0010] In a preferred embodiment, the difference in boiling point between the light component and the heavy component is above 80°C, preferably above 100°C, for example, above 120°C, above 140°C, above 160°C, above 180°C, above 200°C, above 220°C or above 240°C.

[0011] The boiling point of the light component is (much) lower than that of the heavy component. The light component can be a single substance or a mixture of multiple substances, and the heavy component can be a single substance or a mixture of multiple substances.

[0012] In a further preferred embodiment, the light component includes one or more substances having a boiling point between 60 and 120°C, preferably between 70 and 100°C (e.g., 60°C, 70°C, 80°C, 90°C, 100°C, 110°C or 120°C); and / or the heavy component includes one or more substances having a boiling point between 170 and 400°C, preferably between 190 and 360°C (e.g., 170°C, 180°C, 200°C, 220°C, 240°C, 260°C, 280°C, 300°C, 320°C, 350°C, 380°C, 400°C).

[0013] The light component and the heavy component cannot be effectively separated by a single flash evaporation. At least one substance in the light component is a good solvent for dicyclopentadiene dioxide.

[0014] In a further preferred embodiment, the light component includes at least one of cyclohexane, cyclohexene, and benzene; and / or the heavy component includes at least one of dicyclopentadiene dioxide, optional 1-phenylethanol, and optional α,α-dimethylbenzyl alcohol.

[0015] In a preferred embodiment, the boiling point of the third component is higher than the boiling point of the light component and lower than the boiling point of the heavy component, wherein the boiling point of the third component is between the boiling point of the light component and the boiling point of the heavy component.

[0016] In a further preferred embodiment, the boiling point of the third component is 110-180°C, preferably 120-170°C, for example 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C.

[0017] In a further preferred embodiment, the difference in boiling point between the third component and the light component is above 40°C, preferably above 50°C; and / or the difference in boiling point between the third component and the heavy component is above 40°C, preferably above 50°C.

[0018] Wherein, the third component is one substance or a mixture of multiple substances.

[0019] In a preferred embodiment, the third component is a good solvent for the light component and the heavy component.

[0020] Among them, the third component has good solubility for light components and heavy components, and is not easy to react with itself or with light components and heavy components under operating conditions. The inventors have found through experiments that if the third component does not dissolve the light and heavy components, not only can the purpose of the present invention not be achieved, but also the distillation tower will be disordered. If the third component does not dissolve the light components, the top of the tower will be blocked. If the third component does not dissolve the heavy components, the first distillation tower kettle may not be discharged, and the required vaporization rate of the reboiler will be higher.

[0021] In a further preferred embodiment, the third component is selected from at least one of o-xylene, m-xylene, propylbenzene, isopropylcyclohexane, cumene and ethylbenzene, preferably at least one of cumene and ethylbenzene.

[0022] In a preferred embodiment, based on 100 wt % of the mixture, the light component accounts for 60-95 wt % and the heavy component accounts for 5-40 wt %.

[0023] For example, based on 100wt% of the mixture, the light component accounts for 60wt%, 65wt%, 70wt%, 75wt%, 80wt%, 85wt%, 90wt% or 95wt%, and the heavy component accounts for 5wt%, 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt% or 40wt%.

[0024] In a further preferred embodiment, based on 100wt% of the mixture, dicyclopentadiene dioxide accounts for 5-20wt%, preferably 5-15wt%, for example 5wt%, 8wt%, 10wt%, 12wt%, 15wt%, 18wt% or 20wt%.

[0025] In a preferred embodiment, the weight ratio of the third component to the mixture is 1:(1-10), preferably 1:(2-8), for example 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9 or 1:10.

[0026] In a preferred embodiment, based on 0 to 100% of the plates from top to bottom of the first distillation tower, a feed port 1 is provided at 25% to 75% (e.g., 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70% or 75%) of the plates for feeding the multi-component flow.

[0027] In a further preferred embodiment, a mixed stream containing the light component and the third component is withdrawn from the top of the first distillation tower, and a mixed stream containing the heavy component and the third component is withdrawn from the bottom of the tower.

[0028] The present invention innovatively proposes adding a third component with a boiling point between the light component and the heavy component to the mixed raw material, passing the mixed multi-component flow into a first distillation tower, extracting the light component and the third component from the top of the tower, and extracting the third component and the heavy component from the bottom of the tower to a second distillation tower; the third component is mainly extracted from the top of the second distillation tower, and the heavy components such as dicyclopentadiene dioxide are mainly extracted from the bottom of the tower.

[0029] In a preferred embodiment, the conditions of the first distillation tower include: a tower top temperature of 35-90°C, a tower bottom temperature of 100-180°C, a pressure of 5-60 kPaA, and a reflux ratio of 0.1-5.

[0030] For example, the conditions of the first distillation tower include: a top temperature of 35°C, 40°C, 50°C, 60°C, 70°C, 80°C or 90°C, a bottom temperature of 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C or 180°C, a pressure of 5kPaA, 10kPaA, 20kPaA, 30kPaA, 40kPaA, 50kPaA or 60kPaA, and a reflux ratio of 0.1, 1, 2, 3, 4 or 5.

[0031] In a further preferred embodiment, the conditions of the first distillation tower include: a tower top temperature of 40 to 80°C, a tower bottom temperature of 110 to 170°C, a pressure of 10 to 50 kPaA, and a reflux ratio of 0.2 to 3.

[0032] In a preferred embodiment, a reboiler 1 is provided in the bottom of the first distillation tower, and the reboiler 1 is a conventional reboiler; and / or a condenser 1 is provided at the top of the first distillation tower, and the condenser 1 uses cooling water as a cold source.

[0033] The temperature of the cooling water is 20-40° C., preferably 25-35° C. The conventional reboiler refers to other commonly used reboilers other than the scraped-surface evaporator or the falling-film evaporator.

[0034] In a preferred embodiment, based on 0 to 100% of the plates from top to bottom of the second distillation tower, a feed port 2 is provided at 20 to 70% (e.g., 20%, 30%, 40%, 50%, 60% or 70%) of the plates for feeding a mixed flow containing the heavy component and the third component.

[0035] In a further preferred embodiment, the third component is taken out from the top of the second distillation tower, and the heavy component is taken out from the bottom of the tower.

[0036] In a preferred embodiment, the conditions of the second distillation tower include: a tower top temperature of 60-130°C, a tower bottom temperature of 100-170°C, a pressure of 0.1-15 kPaA, and a reflux ratio of 0.1-10.

[0037] For example, the conditions of the second distillation tower include: a top temperature of 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C or 130°C, a bottom temperature of 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C or 170°C, a pressure of 0.1 kPaA, 0.5 kPaA, 1 kPaA, 2 kPaA, 4 kPaA, 6 kPaA, 8 kPaA, 10 kPaA, 12 kPaA, 14 kPaA or 15 kPaA, and a reflux ratio of 0.1, 0.5, 1, 2, 4, 6, 8 or 10.

[0038] In a further preferred embodiment, the conditions of the second distillation tower include: a tower top temperature of 70-120° C., a tower bottom temperature of 110-160° C., a pressure of 1-10 kPaA, and a reflux ratio of 0.2-5.

[0039] In a preferred embodiment, the bottom of the second distillation tower is provided with a reboiler 2 and a reboiler 2 feed pump, and the reboiler 2 feed pump is a solid-liquid transfer pump; and / or, a condenser 2 is provided at the top of the second distillation tower, and the condenser 2 uses cooling water as a cold source.

[0040] In a further preferred embodiment, the second reboiler is a scraped surface evaporator or a falling film evaporator.

[0041] Among them, the inventors found in the research on the separation of dicyclopentadiene dioxide products that dicyclopentadiene dioxide is easy to react at high temperature and has a large viscosity. When separating products containing dicyclopentadiene dioxide, if a conventional reboiler is used, problems such as easy scaling, product carbonization, and easy clogging and damage of the conventional reboiler delivery pump will occur, making it difficult to achieve continuous and stable operation of distillation. Therefore, with a scraper / falling film evaporator as the reboiler and a solid-liquid delivery pump as the second feed pump of the reboiler, in theory, the tower temperature can be reduced by vacuuming and controlling the tower pressure, thereby reducing product carbonization; however, in the present invention, the inventors further found that due to the high content of light components in the raw materials of the mixture, the distillation range of the light and heavy components is large, which will cause the condensation temperature of the tower top to be too low, causing the tower top to require a low-temperature cold source or even solidification / desublimation of the light components, and the problem of too high gasification rate of the reboiler, which ultimately affects the distillation.

[0042] In the present invention, a third distillation tower may be further provided to separate the mixed flow containing the light component and the third component to obtain the light component and the third component respectively. In this way, the third component can be recovered.

[0043] The method of the present invention comprises: (1) introducing a third component into a mixture containing a light component and a heavy component; (2) passing a multi-component flow containing a light component, a heavy component and a third component into a first distillation tower, taking out a mixed flow containing the light component and the third component from the top of the first distillation tower, and taking out a mixed flow containing the heavy component and the third component from the bottom of the tower; (3) passing the bottom discharge of the first distillation tower into a second distillation tower, and mainly taking out the third component from the top of the second distillation tower, and mainly taking out heavy components such as dicyclopentadiene dioxide from the bottom of the tower.

[0044] The second object of the present invention is to provide a system for separating dicyclopentadiene dioxide from a mixture, preferably for carrying out the method described in one of the objects of the present invention, wherein the system comprises a first distillation tower and a second distillation tower connected in series, wherein a reboiler 2 feed pump and a reboiler 2 connected are provided in the bottom of the second distillation tower, the feed pump is a solid-liquid transfer pump, and the reboiler 2 is a scraped evaporator or a falling film evaporator.

[0045] In a preferred embodiment, a first feed inlet is provided on the first distillation tower, and a second feed inlet is provided on the second distillation tower.

[0046] In a further preferred embodiment, the bottom of the first distillation tower is connected to the second feed inlet of the second distillation tower.

[0047] In a preferred embodiment, the system further comprises a mixture raw material feed pipeline and a third component feed pipeline.

[0048] In a further preferred embodiment, the mixture raw material feed pipeline is first connected to the third component feed pipeline and then connected to the first distillation tower (preferably to its feed port 1).

[0049] In a preferred embodiment, a first condenser and a second condenser are respectively disposed at the top of the first distillation tower and the top of the second distillation tower, and the first condenser and the second condenser each independently use cooling water as a cold source.

[0050] The endpoints and any values ​​of the scope disclosed in the present invention are not limited to the precise scope or value, and these scopes or values ​​should be understood to include values ​​close to these scopes or values. For numerical ranges, the endpoint values ​​of each scope, the endpoint values ​​of each scope and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be regarded as specifically disclosed in this article. Hereinafter, in principle, each technical solution can be combined with each other to obtain a new technical solution, which should also be regarded as specifically disclosed in this article.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] (1) The added third component can be subsequently separated and recovered, and theoretically there is no loss problem;

[0053] (2) Negative pressure operation can effectively reduce the temperature of the tower bottom, save energy consumption, and avoid the reaction of dicyclopentadiene dioxide;

[0054] (3) The top product of the first distillation tower contains the third component, which can effectively increase the condensation temperature (because the bubble point of the light component alone is low, while the bubble point of the third component is high, and the melting point of the third component is low, which can dissolve the light component, so the bubble point of the mixture of the two is between the light component and the third component, thus increasing the top condensation temperature). The condenser does not need to use a subcooling medium, saving energy consumption and avoiding the problem of solidification / desublimation of the light component;

[0055] (4) The problem of excessively high vaporization rate of scraper evaporator / falling film evaporator is solved, and it is highly feasible. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 A schematic diagram showing the process of the method of the present invention Figure 1 .

[0057] exist Figure 1In the figure, A-first distillation tower, B-second distillation tower, E-reboiler 2, P-reboiler feed pump. 1-mixture feed, 2-third component, 3-multi-component flow, 4-mixture flow containing light component and third component, 5-mixture flow containing heavy component and third component, 6-second distillation tower top product, 7-second distillation tower bottom liquid, 8-reboiler 2 feed, 9-reboiler 2 gas phase discharge, 10-reboiler 2 liquid phase discharge.

[0058] In adopting Figure 1 When the system is shown:

[0059] The third component 2 is added to the mixed raw material 1 to obtain a multi-component stream 3, which enters the first distillation tower A for separation, and a mixed stream 4 containing a light component and a third component is obtained at the top of the tower, and a mixed stream 5 containing a heavy component and a third component is obtained at the bottom of the tower. The mixed stream 5 containing the heavy component and the third component enters the second distillation tower B for separation, and the third component is obtained at the top of the tower. The bottom liquid 7 is pressurized by the second feed pump P of the second distillation tower reboiler to obtain the second feed 8 of the second distillation tower reboiler, which enters the reboiler E. The feed pump P of the second reboiler is a solid-liquid delivery pump, and the reboiler uses a scraper evaporator or a falling film evaporator. The second gas phase discharge 9 of the second distillation tower reboiler returns to the bottom of the tower, and the second liquid phase discharge 10 of the second distillation tower reboiler goes downstream.

[0060] It should be noted that the omission of necessary equipment and pipelines such as the condenser, reboiler, reflux tank, etc. of the above-mentioned tower does not mean that they do not exist.

[0061] Figure 2 A schematic flow diagram of Comparative Example 1 is shown.

[0062] exist Figure 2 In the figure, A'-distillation tower. 1-mixed raw material, 2'-tower top product, 3'-tower bottom product. The mixed raw material 1 is passed into the distillation tower A' for separation, and the tower top product 2' is taken out from the tower top, and the tower bottom product 3' is taken out from the tower bottom. It should be noted that the condenser, reflux tank and other necessary equipment and pipelines of the above tower are omitted, which does not mean that they do not exist. The tower bottom reboiler adopts an ordinary reboiler, and the reboiler feed pump adopts an ordinary pump.

[0063] Figure 3 The process diagram of comparative example 2 is shown Figure 3 .

[0064] exist Figure 3In the figure, A'-distillation tower, E'-reboiler, P'-reboiler feed pump. 1-mixture raw material, 2'-top product, 4'-reboiler feed, 5'-reboiler gas phase discharge, 6'-reboiler liquid phase discharge. Wherein, the mixture 1 is passed into the distillation tower A' for separation, the top product 2' is taken out from the top of the tower, and the bottom liquid is pressurized by the reboiler feed pump P' to obtain the reboiler feed 4' and enter the reboiler E'. The reboiler feed pump P' is a solid-liquid transfer pump, and the reboiler uses a scraped evaporator or a falling film evaporator. The reboiler gas phase discharge 5' returns to the bottom of the tower, and the reboiler liquid phase discharge 6' is discharged to the downstream. It should be noted that the condenser, reflux tank and other necessary equipment and pipelines of the above-mentioned tower are omitted and not drawn, which does not mean that they do not exist.

[0065] Figure 4 The schematic diagram of comparative example 3 is shown Figure 4 .

[0066] exist Figure 4 In the figure, A”-flash tank. 1-mixture, 2”-top product, 3”-bottom product.

[0067] In adopting Figure 4 When the system is shown:

[0068] The light and heavy component mixture 1 is passed into a flash tank 1 for separation, and a top product 2" is taken from the top of the tank, and a bottom product 3" is taken from the bottom of the tank. DETAILED DESCRIPTION

[0069] The present invention is described in detail below in conjunction with specific embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by those skilled in the art based on the contents of the present invention still fall within the scope of protection of the present invention.

[0070] It should also be noted that the various specific technical features described in the following specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0071] In addition, the various embodiments of the present invention may be arbitrarily combined as long as they do not violate the concept of the present invention. The technical solutions thus formed belong to part of the original disclosure of this specification and also fall within the protection scope of the present invention.

[0072] The raw materials used in the examples and comparative examples, unless otherwise specified, are disclosed in the prior art, for example, they can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0073] [Example 1]

[0074] like Figure 1 As shown, in terms of weight percentage, cumene is added to a mixture containing 85.00% of cyclohexane, 5.00% of α,α-dimethylbenzyl alcohol, and 10.00% of dicyclopentadiene dioxide, and the ratio of the mass flow rate of cumene to the mass flow rate of the mixture is 1:5; the multi-component stream obtained after mixing is added from the 15th plate of the first distillation tower A, the tower top pressure is 30 kPaA, the tower top temperature is 68°C, the condenser uses cooling water as a cold source, the tower bottom temperature is 148°C, the number of tower plates is 30, the reflux ratio is 1, and the reboiler uses a conventional reboiler. The bottom product of the first distillation tower is added from the 10th plate (from top to bottom) of the second distillation tower B. In the second distillation tower, the top pressure is 6kPaA, the top temperature is 99°C, the second condenser uses cooling water as a cold source, the bottom temperature is 135°C, the outlet temperature of the second reboiler is 164°C, the number of plates is 25, the reflux ratio is 1, the feed pump of the second reboiler uses a solid-liquid transfer pump, the second reboiler uses a scraper steamer, and the gasification rate is 50.72%.

[0075] The top product of the first distillation tower has a composition of 85.00% cyclohexane and 15.00% cumene.

[0076] The product composition of the bottom of the first distillation tower is 25.00% of isopropylbenzene, 25.00% of α,α-dimethylbenzyl alcohol, and 50.00% of dicyclopentadiene dioxide.

[0077] The top product of the second distillation tower consists of 62.50% cumene and 37.50% α,α-dimethylbenzyl alcohol.

[0078] The product composition of the bottom of the second distillation tower is 16.67% of α,α-dimethylbenzyl alcohol, 83.17% of dicyclopentadiene dioxide, and 0.16% of carbide.

[0079] The first distillation tower and the second distillation tower operated continuously and stably, and the recovery rate of dicyclopentadiene dioxide was 99.80%.

[0080] [Example 2]

[0081] like Figure 1As shown, in terms of weight percentage, cumene is added to a mixture containing 86.20% of cyclohexene, 4.50% of α,α-dimethylbenzyl alcohol, and 9.30% of dicyclopentadiene dioxide, and the ratio of the mass flow rate of cumene to the mass flow rate of the mixture is 1:5. The multi-component stream obtained after mixing is added from the 15th plate of the first distillation tower A, the tower top pressure is 30 kPaA, the tower top temperature is 66°C, the condenser uses cooling water as a cold source, the tower bottom temperature is 143°C, the number of tower plates is 30, the reflux ratio is 1, and the reboiler uses a conventional reboiler. The bottom product of the first distillation tower is added from the 10th plate of the second distillation tower B. The top pressure is 6kPaA, the top temperature is 96°C, the condenser 2 uses cooling water as the cold source, the bottom temperature is 133°C, the outlet temperature of the reboiler 2 is 166°C, the number of plates is 25, the reflux ratio is 1, the reboiler 2 feed pump uses a solid-liquid transfer pump, the reboiler 2 uses a scraper steamer, and the gasification rate is 56.03%.

[0082] The top product of the first distillation tower consists of 86.20% cyclohexene and 13.80% cumene.

[0083] The product composition of the bottom of the first distillation tower is 31.00% of isopropylbenzene, 22.50% of α,α-dimethylbenzyl alcohol and 46.50% of dicyclopentadiene dioxide.

[0084] The top product composition of the second distillation tower is 68.89% of cumene and 31.11% of α,α-dimethylbenzyl alcohol.

[0085] The product composition of the bottom of the second distillation tower is 15.45% of α,α-dimethylbenzyl alcohol, 84.33% of dicyclopentadiene dioxide, and 0.22% of carbide.

[0086] The first distillation tower and the second distillation tower operated continuously and stably, and the recovery rate of dicyclopentadiene dioxide was 99.74%.

[0087] [Example 3]

[0088] like Figure 1As shown, in terms of weight percentage, ethylbenzene is added to a mixture containing 85.00% of cyclohexane, 5.00% of 1-phenylethanol, and 10.00% of dicyclopentadiene dioxide, and the ratio of the mass flow rate of ethylbenzene to the mass flow rate of the mixture is 1:5. The multi-component stream obtained after mixing is added from the 15th plate of the first distillation tower A, the tower top pressure is 30 kPaA, the tower top temperature is 58°C, the condenser uses cooling water as a cold source, the tower bottom temperature is 128°C, the number of tower plates is 30, the reflux ratio is 1, and the reboiler uses a conventional reboiler. The bottom product of the first distillation tower is added from the 10th plate (from top to bottom) of the second distillation tower B. In the second distillation tower, the top pressure is 6kPaA, the top temperature is 98°C, the condenser 2 uses cooling water as a cold source, the bottom temperature is 134°C, the outlet temperature of the reboiler 2 is 163°C, the number of plates is 25, the reflux ratio is 1, the reboiler 2 feed pump uses a solid-liquid transfer pump, the reboiler 2 uses a falling film steamer, and the vaporization rate is 53.62%.

[0089] The composition of the top product of the first distillation tower is 85.00% cyclohexane and 15.00% ethylbenzene.

[0090] The product composition of the bottom of the first distillation tower is 25.00% of ethylbenzene, 25.00% of 1-phenylethanol, and 50.00% of dicyclopentadiene dioxide.

[0091] The top product of the second distillation tower comprises 62.51% ethylbenzene and 37.49% 1-phenylethanol.

[0092] The product composition of the bottom of the second distillation tower is 16.67% of 1-phenylethanol, 83.14% of dicyclopentadiene dioxide, and 0.19% of carbide.

[0093] The first distillation tower and the second distillation tower operated continuously and stably, and the recovery rate of dicyclopentadiene dioxide was 99.77%.

[0094] [Example 4]

[0095] like Figure 1As shown, in terms of weight percentage, ethylbenzene is added to a mixture containing 83.00% of cyclohexene, 5.50% of 1-phenylethanol, and 11.50% of dicyclopentadiene dioxide, and the ratio of the mass flow rate of ethylbenzene to the mass flow rate of the mixture is 1:5. The multi-component stream obtained after mixing is added from the 15th plate of the first distillation tower A, the tower top pressure is 30 kPaA, the tower top temperature is 62°C, the condenser uses cooling water as a cold source, the tower bottom temperature is 144°C, the number of tower plates is 30, the reflux ratio is 1, and the reboiler uses a conventional reboiler. The bottom product of the first distillation tower is added from the 10th plate of the second distillation tower B. The top pressure is 6kPaA, the top temperature is 104°C, the condenser 2 uses cooling water as the cold source, the bottom temperature is 137°C, the outlet temperature of the reboiler 2 is 161°C, the number of plates is 25, the reflux ratio is 1, the reboiler 2 feed pump uses a solid-liquid transfer pump, the reboiler 2 uses a falling film steamer, and the gasification rate is 41.97%.

[0096] The composition of the top product of the first distillation tower is 83.00% cyclohexene and 17.00% ethylbenzene.

[0097] The product composition of the bottom of the first distillation tower is 15.00% of ethylbenzene, 27.50% of 1-phenylethanol, and 57.50% of dicyclopentadiene dioxide.

[0098] The top product of the second distillation tower comprises 50.00% ethylbenzene and 50.00% 1-phenylethanol.

[0099] The product composition of the bottom of the second distillation tower is 17.86% of 1-phenylethanol, 81.99% of dicyclopentadiene dioxide, and 0.15% of carbide.

[0100] The first distillation tower and the second distillation tower operated continuously and stably, and the recovery rate of dicyclopentadiene dioxide was 99.81%.

[0101] [Comparative Example 1]

[0102] like Figure 2 As shown, a mixture containing 85% cyclohexane, 5% α,α-dimethylbenzyl alcohol, and 10% dicyclopentadiene dioxide, by weight percentage, is added from the 10th plate of the distillation tower A', the top pressure is 6 kPaA, the number of plates is 30, the reboiler feed pump is a centrifugal pump, and the reboiler is a conventional reboiler.

[0103] Because the heavy components in the tower bottom have a high viscosity, solids precipitate when cooled, causing damage to the centrifugal pump impeller and fouling and clogging of the reboiler, and the tower cannot operate normally and stably.

[0104] [Comparative Example 2]

[0105] like Figure 3As shown, in terms of weight percentage, a mixture of light and heavy components containing 85% cyclohexane, 5% α,α-dimethylbenzyl alcohol, and 10% dicyclopentadiene dioxide is added from the 16th plate of the distillation tower, the tower top pressure is 5 kPaA, the tower top temperature is 40°C, the condenser uses ethylene glycol refrigerant as a cold source, the tower bottom temperature is 120°C, the reboiler outlet temperature is 151°C, the number of tower plates is 30, the reflux ratio is 0.5, the reboiler feed pump uses a solid-liquid transfer pump, the reboiler uses a falling film steamer, and the gasification rate is 91.28%.

[0106] Since the temperature of the top gas after condensation is 5°C, which is lower than the triple point temperature of cyclohexane of 6.3°C, cyclohexane condenses into solid and blocks the top condenser. In addition, the reboiler vaporization rate is difficult to reach 91.28%, so the tower cannot operate normally and stably.

[0107] [Comparative Example 3]

[0108] like Figure 4 As shown, a mixture of light and heavy components containing 85% cyclohexane, 5% α,α-dimethylbenzyl alcohol and 10% dicyclopentadiene dioxide, by weight percentage, is introduced into a flash tank, the tank pressure is normal pressure, and the temperature is 140°C.

[0109] The composition of the tank top product is 96.03% cyclohexane, 3.52% α,α-dimethylbenzyl alcohol, and 0.45% dicyclopentadiene dioxide.

[0110] The composition of the product at the bottom of the tank is 14.23% cyclohexane, 14.50% α,α-dimethylbenzyl alcohol, and 71.27% dicyclopentadiene dioxide.

[0111] The recovery rate of dicyclopentadiene dioxide is 96.14%. It can be seen that the single flash distillation method not only fails to obtain heavy components without light components, but also causes part of dicyclopentadiene dioxide to be discharged from the top of the tower, resulting in losses.

[0112] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

Claims

1. A method for separating dicyclopentadiene dioxide from a mixture containing light components and heavy components containing dicyclopentadiene dioxide, the method comprising: A third component is introduced into the mixture to form a multi-component stream, and the multi-component stream then enters a first distillation tower and a second distillation tower connected in series in sequence for separation to obtain dicyclopentadiene dioxide.

2. The method according to claim 1, characterized in that The difference in boiling point between the light component and the heavy component is above 80°C, preferably above 100°C; Preferably, the light component comprises one or more substances having a boiling point between 60 and 120°C, preferably between 70 and 100°C; and / or, the heavy component comprises one or more substances having a boiling point between 170 and 400°C, preferably between 190 and 360°C; More preferably, the light component comprises at least one of cyclohexane, cyclohexene and benzene; and / or the heavy component comprises at least one of dicyclopentadiene dioxide, optional 1-phenylethanol and optional α,α-dimethylbenzyl alcohol.

3. The method according to claim 1, characterized in that The boiling point of the third component is higher than the boiling point of the light component and lower than the boiling point of the heavy component; The difference in boiling point between the third component and the light component is above 40°C, preferably above 50°C; and / or the difference in boiling point between the third component and the heavy component is above 40°C, preferably above 50°C.

4. The method according to claim 1, characterized in that: The third component is a good solvent for the light component and the heavy component; preferably, the third component is selected from at least one of o-xylene, m-xylene, propylbenzene, isopropylcyclohexane, cumene, and ethylbenzene, preferably at least one of cumene and ethylbenzene.

5. The method according to claim 1, characterized in that Based on 100 wt% of the mixture, the light component accounts for 60-95 wt% and the heavy component accounts for 5-40 wt%; and / or, Based on 100 wt % of the mixture, dicyclopentadiene dioxide accounts for 5 to 20 wt %, preferably 5 to 15 wt %.

6. The method according to claim 1, characterized in that The weight ratio of the third component to the mixture is 1:(1-10), preferably 1:(2-8).

7. The method according to claim 1, characterized in that The conditions of the first distillation tower include: a top temperature of 35 to 90°C, a bottom temperature of 100 to 180°C, a pressure of 5 to 60 kPaA, and a reflux ratio of 0.1 to 5; preferably, the top temperature is 40 to 80°C, the bottom temperature is 110 to 170°C, the pressure is 10 to 50 kPaA, and the reflux ratio is 0.2 to 3.

8. The method according to any one of claims 1 to 6, characterized in that: The conditions of the second distillation tower include: a top temperature of 60-130°C, a bottom temperature of 100-170°C, a pressure of 0.1-15 kPaA, and a reflux ratio of 0.1-10; preferably, the top temperature is 70-120°C, the bottom temperature is 110-160°C, the pressure is 1-10 kPaA, and the reflux ratio is 0.2-5.

9. The method according to claim 8, characterized in that A reboiler 1 is provided at the bottom of the first distillation tower; and / or a condenser 1 is provided at the top of the first distillation tower; A second reboiler is provided at the bottom of the second distillation tower. Preferably, the second reboiler is a scraped-surface evaporator or a falling-film evaporator; and / or a second condenser is provided at the top of the second distillation tower.

10. A system for separating dicyclopentadiene dioxide from a mixture, preferably for carrying out the method according to any one of claims 1 to 9, the system comprising a first distillation tower and a second distillation tower connected in series, wherein: The bottom of the second distillation tower is provided with a connected reboiler second feed pump and a reboiler second, wherein the feed pump is a solid-liquid delivery pump, and the reboiler second is a scraper evaporator or a falling film evaporator.

11. The system according to claim 10, characterized in that The system further comprises a mixture raw material feed pipeline and a third component feed pipeline; preferably, the mixture raw material feed pipeline is first connected to the third component feed pipeline and then connected to the first distillation tower.

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