DCPD-rich mixture separation extraction agent and application
By using phenol, o-cresol, methanol or benzyl alcohol as extraction agents, combined with reduced pressure and heat treatment, the relative volatility of DCPD and other C9 aromatic compounds was successfully improved, and the problems of poor operating flexibility and high energy consumption in traditional separation methods were solved, and efficient and environmentally friendly DCPD separation effect was achieved.
Patent Information
- Application Number
- CN202510392300.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-31
- Publication Date
- 2025-07-04
AI Technical Summary
The prior art is difficult to efficiently separate dicyclopentadiene (DCPD) from other C9 aromatic compounds, especially the separation problems caused by the close azeotropic points. The traditional method has poor operation flexibility, high energy consumption and unfriendly environment.
The mixture with DCPD is extracted and separated under reduced pressure and heating conditions by adjusting the molar ratio and pressure of the extractant to the mixture, and the relative volatility of DCPD and other components is increased.
It significantly improves the relative volatility of DCPD and other C9 aromatic compounds, solves the azeotropic problem, and achieves efficient, low-cost and environmentally friendly separation effects.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention belongs to the field of extraction and separation of organic mixtures, and particularly relates to a separation extractant for a DCPD-rich mixture and its application. Background Art
[0002] Dicyclopentadiene, also known as dicyclopentadiene (DCPD), belongs to a kind of norbornene. It is a dimer formed by the polymerization of cyclopentadiene and exists in two isomers, namely the endo form and the exo form. According to purity, it can be divided into low-purity / polyester grade (68% - 80%), ethylene propylene diene monomer (EPDM) grade (95% - 99%), and polymerization grade (greater than or equal to 99%). DCPD is colorless crystals at room temperature. With a molecular structure containing conjugated double bonds and methylene groups, it has special reaction efficacy. Therefore, it is not only an important raw material in organic chemical production but also a good intermediate. This substance can be widely used in many fields such as pesticides, spices, dyes, adhesives, catalysts, and resins. A kind of alicyclic petroleum resin formed by the thermal polymerization of dicyclopentadiene is called dicyclopentadiene petroleum resin. This resin does not soften at room temperature and has excellent adhesion and stability reliability within a certain temperature range.
[0003] The content of dicyclopentadiene in C9 aromatic hydrocarbon compounds is relatively high, and the boiling points of dicyclopentadiene, p-methylstyrene, mesitylene, and pseudocumene are close. Therefore, it is very difficult to separate the easily azeotropic dicyclopentadiene mixture with high purity from a technical perspective by using traditional separation methods for the DCPD-rich mixture. However, the development of advanced separation technologies creates opportunities for it, and the separation goal can be achieved through various methods, such as extraction separation under low pressure. Extraction separation mainly adds a third substance to a near-boiling or azeotropic mixture system to increase the relative volatility between the substances to be separated to complete the separation task. Compared with emerging separation methods, traditional separation methods are generally used for DCPD-rich mixtures because of their poor operation flexibility, high energy consumption, environmental unfriendliness, and large loss of active ingredients. However, extraction separation has significant advantages compared with traditional separation methods. It can achieve highly selective extraction of target components according to the solubility differences of target substances in different solvents. It is simple to operate and has low cost, energy-saving and environmental protection, and low energy consumption.
[0004] A suitable extractant should meet the characteristics of having high selectivity, good solubility, strong chemical stability, and high boiling point. For selecting an effective extractant that can effectively separate the substances in the DCPD and DCPD-rich mixture, the infinite dilution activity coefficient in the DCPD-rich mixture can be calculated first through COSMO simulation, and then the selectivity of the extractant for the separation system can be calculated. In thermodynamics, the infinite dilution activity coefficient can be used to describe the intermolecular interaction. If the infinite dilution activity coefficient of a certain solute in a specific solvent is smaller, it indicates that the solute has greater solubility in the corresponding solvent, that is, the solute molecules and solvent molecules have greater interaction energy. Thus, specific better extractants can be judged and screened out. This method avoids a large number of blind experiments and saves time and effort. Then, through the determination of vapor-liquid equilibrium data, the selected extractants are screened in detail, and the influence of different extractants on the relative volatility between the substances in the DCPD and DCPD-rich mixture is compared, so as to select the best extractant that can effectively separate the substances in the DCPD and DCPD-rich mixture. The combination of the two methods can screen out the best extractant that can well separate DCPD.
[0005] In summary, the C9 aromatics have a complex composition, close boiling points, and are difficult to separate. There is little research on the extraction and separation of DCPD from C9 aromatic compounds. At the same time, extraction separation is superior to traditional separation methods in terms of selectivity, efficiency, energy consumption, environmental protection, etc. Selecting the best extractant can make DCPD better separated from the DCPD-rich mixture. Summary of the Invention
[0006] The present application provides an extractant for separating DCPD-rich mixture, and the extractant is one or more of phenol, o-cresol, methanol, and benzyl alcohol.
[0007] Preferably, the extractant is one or more of phenol, o-cresol, and methanol.
[0008] The present application also provides an application of the above extractant in extracting and separating DCPD from the DCPD-rich mixture, including the following steps: mixing the extractant with the DCPD-rich mixture, reducing pressure and heating for extraction.
[0009] Preferably, the molar ratio of the extractant to the DCPD-rich mixture is 0.5-2:1 (such as 2:1, 1:1, 0.5:1).
[0010] Preferably, the DCPD-rich mixture includes dicyclopentadiene, p-methylstyrene, mesitylene, and pseudocumene.
[0011] Preferably, the heating temperature is 160-200 °C.
[0012] Preferably, the pressure for pressure reduction is 20-100 kPa (such as 20 kPa, 50 kPa, 100 kPa).
[0013] Preferably, the DCPD-rich mixture includes dicyclopentadiene, p-methylstyrene, mesitylene, and pseudocumene.
[0014] In an alternative embodiment, the DCPD-rich mixture is composed of the following components: the mass fraction of dicyclopentadiene is 62.21%, the mass fraction of p-methylstyrene is 23.01%, the mass fraction of mesitylene is 7.06%, and the mass fraction of pseudocumene is 7.72%.
[0015] Advantages of the present invention: By introducing a new extractant, the relative volatility of the DCPD-p-methylstyrene system and the DCPD-mesitylene system is successfully increased to more than 2, and the relative volatility of the DCPD-pseudocumene system is increased to more than 1.2. It shows excellent universality for DCPD mixed systems containing aromatics with different substituents (methyl, trimethylbenzene isomers), especially overcoming the azeotropic problem caused by the low original relative volatility of the pseudocumene system, and providing a general solution for the customized separation of components of complex industrial mixtures. Description of the Drawings
[0016] Figure 1 It is the saturated vapor pressures of pure components dicyclopentadiene, p-methylstyrene, mesitylene, and pseudocumene at a certain temperature in the specific examples and comparative examples of the present application. Detailed Embodiments
[0017] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following describes the detailed embodiments of the present invention in conjunction with the embodiments of the specification.
[0018] Many specific details are set forth in the following description to facilitate a thorough understanding of the present invention, but the present invention may be practiced in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the spirit of the present invention, so the present invention is not limited by the specific embodiments disclosed below.
[0019] For the vapor-liquid equilibrium data of the specific implementation mode of this application, gas chromatography was used for analysis. The analysis conditions were as follows: HP-1 chromatographic column (60m×0.25mm×0.50μm). FID detector was used for analysis, the injection volume was 1μl, and each sample was measured at least 3 times. The column oven was programmed to increase the temperature: stay at 90°C for 2 min, increase the temperature to 120°C at a rate of 2°C / min and stay for 5 min, increase the temperature to 160°C at a rate of 10°C / min and stay for 5 min, increase the temperature to 220°C at a rate of 10°C / min and stay for 5 min. The injector temperature was set at 270°C, and the detector temperature was set at 290°C.
[0020] The relative volatilities of DCPD with p-methylstyrene, mesitylene, and pseudocumene in this application were obtained through the following method. The specific steps were as follows:
[0021] (1) Prepare the DCPD-rich mixture: Mix DCPD with p-methylstyrene, mesitylene, and pseudocumene to prepare a DCPD-rich mixture, in which dicyclopentadiene accounts for 62.21%, p-methylstyrene accounts for 23.01%, mesitylene accounts for 7.06%, and pseudocumene accounts for 7.72%.
[0022] (2) Mix the extractant and the DCPD-rich mixture according to a molar ratio of 0.5-2:1, and mix the extractant and the DCPD-rich mixture evenly to obtain mixture A; the extractant includes benzyl alcohol, methanol, phenol, and o-cresol.
[0023] In the specific examples of this application, the molar ratio of the extractant to the DCPD-rich mixture is 2:1, 1:1, and 0.5:1. If too little extractant is used, it is not conducive to the extraction and separation of DCPD; if too much extractant is used, it will cause waste and is not environmentally friendly.
[0024] (3) At different pressures, heat the DCPD-rich mixture and mixture A to 160-200°C respectively, extract for 3-4 h, and after reaching phase equilibrium stability, take samples for gas chromatography instrument analysis; the different pressures include 20 kPa, 50 kPa, and 100 kPa. By setting the extraction conditions in this way, the extractant that can achieve the best separation effect of the DCPD-rich mixture can be screened out. Different pressures will affect the effect of the extractant; if the heating temperature of the reaction is higher than 200°C, it will affect the extraction and separation of DCPD in the DCPD-rich mixture by the extractant. If the temperature is lower than 160°C, it is not conducive to the sufficiency of extraction, thereby reducing the separation effect of DCPD in the DCPD-rich mixture.
[0025] (4) Calculate the relative volatility between each substance in the DCPD and the DCPD-rich mixture in different extractants according to the basic conditions of thermodynamic phase equilibrium. The relative volatility can be obtained according to the basic conditions of thermodynamic phase equilibrium, and the calculation formula is: In the formula, y i refers to the mole fraction of component i in the vapor phase, and y j refers to the mole fraction of component j in the vapor phase, and x i refers to the mole fraction of component i in the liquid phase, and x j refers to the mole fraction of component j in the liquid phase. Where i refers to the DCPD component, and j refers to any one of the required components in p-methylstyrene, mesitylene, and pseudocumene.
[0026] Example 1
[0027] (1) Prepare the DCPD-rich mixture: Mix DCPD with p-methylstyrene, mesitylene, and pseudocumene, where dicyclopentadiene accounts for 62.21%, p-methylstyrene accounts for 23.01%, mesitylene accounts for 7.06%, and pseudocumene accounts for 7.72%;
[0028] (2) Use phenol as the extractant and mix it with the DCPD-rich mixture evenly at a molar ratio of 2:1 to obtain mixture A. A total of 50 ml is weighed, and a vapor-liquid equilibrium experiment is carried out on mixture A. Heat it in an oil bath to 160 °C and measure the binary system vapor-liquid equilibrium data of each substance in the DCPD and the DCPD-rich mixture under 20 kPa;
[0029] (3) Calculate the relative volatility between each substance in the DCPD and the DCPD-rich mixture according to the basic conditions of thermodynamic phase equilibrium.
[0030] The specific conditions and the relative volatility between each substance in the DCPD and the DCPD-rich mixture are shown in Table 1.
[0031] Example 2
[0032] The implementation steps and conditions are basically the same as those in Example 1. The difference is that o-cresol is used as the extractant. The specific conditions and the relative volatility between each substance in the DCPD and the DCPD-rich mixture in this example are shown in Table 1.
[0033] Example 3
[0034] The implementation steps and conditions are basically the same as those in Example 1. The difference is that methanol is used as the extractant. The specific conditions and the relative volatility between each substance in the DCPD and the DCPD-rich mixture in this example are shown in Table 1.
[0035] Example 4
[0036] The implementation steps and conditions are basically the same as those in Example 1. The difference is that benzyl alcohol is used as the extractant. The specific conditions of this example and the relative volatilities between various substances in the DCPD and DCPD-rich mixture are shown in Table 1.
[0037] Example 5
[0038] The implementation steps and conditions are basically the same as those in Example 1. The difference is that the molar ratio of phenol to the DCPD-rich mixture is 1:1. The specific conditions of this example and the relative volatilities between various substances in the DCPD and DCPD-rich mixture are shown in Table 1.
[0039] Example 6
[0040] The implementation steps and conditions are basically the same as those in Example 5. The difference is that o-cresol is used as the extractant. The specific conditions of this example and the relative volatilities between various substances in the DCPD and DCPD-rich mixture are shown in Table 1.
[0041] Example 7
[0042] The implementation steps and conditions are basically the same as those in Example 5. The difference is that methanol is used as the extractant. The specific conditions of this example and the relative volatilities between various substances in the DCPD and DCPD-rich mixture are shown in Table 1.
[0043] Example 8
[0044] The implementation steps and conditions are basically the same as those in Example 5. The difference is that benzyl alcohol is used as the extractant. The specific conditions of this example and the relative volatilities between various substances in the DCPD and DCPD-rich mixture are shown in Table 1.
[0045] Example 9
[0046] The implementation steps and conditions are basically the same as those in Example 1. The difference is that the molar ratio of phenol to the DCPD-rich mixture is 0.5:1. The specific conditions of this example and the relative volatilities between various substances in the DCPD and DCPD-rich mixture are shown in Table 1.
[0047] Example 10
[0048] The implementation steps and conditions are basically the same as those in Example 9. The difference is that o-cresol is used as the extractant. The specific conditions of this example and the relative volatilities between various substances in the DCPD and DCPD-rich mixture are shown in Table 1.
[0049] Example 11
[0050] The implementation steps and conditions are basically the same as those in Example 9. The difference is that methanol is used as the extractant. The specific conditions of this example and the relative volatilities between various substances in the DCPD and DCPD-rich mixture are shown in Table 1.
[0051] Example 12
[0052] The implementation steps and conditions are basically the same as those in Example 9. The difference is that benzyl alcohol is used as the extractant. The specific conditions of this example and the relative volatility between various substances in the DCPD and rich DCPD mixture are shown in Table 1.
[0053] Example 13
[0054] The implementation steps and conditions are basically the same as those in Example 1. The difference is that the vapor-liquid equilibrium data are measured at 50 kPa. The specific conditions of this example and the relative volatility between various substances in the DCPD and rich DCPD mixture are shown in Table 1.
[0055] Example 14
[0056] The implementation steps and conditions are basically the same as those in Example 1. The difference is that the vapor-liquid equilibrium data are measured at 100 kPa. The specific conditions of this example and the relative volatility between various substances in the DCPD and rich DCPD mixture are shown in Table 1.
[0057] Comparative Example 1
[0058] The implementation steps and conditions are basically the same as those in Example 1. The difference is that there is no extractant, and 50 ml of the rich DCPD mixture is directly weighed for the determination of vapor-liquid equilibrium experiment data. The specific conditions of this comparative example and the relative volatility between various substances in the DCPD and rich DCPD mixture are shown in Table 1.
[0059] Table 1 Extraction separation conditions and results of DCPD in examples and comparative examples
[0060]
[0061] In the above examples of the present application, the influence of different pressure conditions, different types of extractants, and the ratio of extractant to rich DCPD mixture on the relative volatility of various substances in the rich DCPD mixture to DCPD, that is, the influence on the extraction separation effect of DCPD, is shown. Under the conditions of the same pressure and the same solvent ratio, the extraction separation effect is the best with phenol as the extractant (Example 1); when the solvent ratio is reduced under the condition that all other conditions are the same, the extraction effect is significantly reduced (Comparative Example 1, Example 5, and Example 9). Under the conditions of the same extractant and the same solvent ratio, the relative volatility between various substances in the DCPD and rich DCPD mixture is the largest at a pressure of 20 kPa, and the extraction separation effect is the best (Example 1). When the pressure is increased under the condition that all other conditions are the same, the extraction effect is significantly reduced (Comparative Example 1, Example 13, and Example 14).
[0062] In summary, in the screening of the extractant used in the specific embodiments of the present application for separating DCPD, the relative volatility of DCPD and each substance in the DCPD-rich mixture is significantly increased. Applying it to the extractive distillation of the DCPD-rich mixture can improve the extraction separation effect of DCPD.
[0063] Taking the above ideal embodiments based on the present invention as an inspiration, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of the present invention. The technical scope of the present invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.
Claims
1. A separating extractant for a DCPD-rich mixture, characterized in that, The extractant is one or more of phenol, o-cresol, methanol, and benzyl alcohol.
2. The application of the extraction agent for separating the DCPD-rich mixture according to claim 1, characterized in that, Mix the extractant with the DCPD-rich mixture, reduce the pressure and heat for extraction.
3. The application of the separating extractant for the DCPD-rich mixture according to claim 2, wherein The molar ratio of the extractant to the DCPD-rich mixture is 0.5-2:
1.
4. Use of the extraction agent for separating the DCPD-rich mixture according to claim 2, characterized in that, The DCPD-rich mixture includes dicyclopentadiene, p-methylstyrene, sym-trimethylbenzene, and mesitylene.
5. Use of the extraction agent for separating the DCPD-rich mixture according to claim 2, characterized in that, The heating temperature is 160-200°C.
6. The application of the extraction agent for separating the DCPD-rich mixture according to claim 2, wherein, The pressure for reducing pressure is 20-100 kPa.