Production process and system for epoxy cycloalkane

Abstract

The present invention provides a production process and system for epoxy cycloalkane. The process comprises an oxidation procedure, a first refining procedure, a hydrogenation procedure, and a second refining procedure. The oxidation procedure is carried out in N reaction kettles connected in series, and a discharge port of the previous reaction kettle is connected to a feed port of the next reaction kettle. A starting material cycloolefin and a solvent are fed into a feed port of the first reaction kettle, while an oxidant hydrogen peroxide is divided into N-1 portions and respectively added to the first reaction kettle to the (N-1)th reaction kettle. A first material obtained after an oxidation reaction is discharged from a discharge port of the last reaction kettle. Unreacted cycloolefin separated out in the first refining procedure is returned to the oxidation procedure. The molar ratio of the cycloolefin to the hydrogen peroxide is (2-7):1. According to the present invention, a plurality of synergistic technical features are provided to improve the effective utilization rate of hydrogen peroxide, improve the product yield, and promote the complete reaction of hydrogen peroxide. The production process is a safe and high-yield process suitable for large-scale industrial production.

Description

Process and system for producing an epoxy cycloalkane TECHNICAL FIELD

[0001] The present application relates to the technical field of organic synthesis, and particularly relates to a process and system for producing an epoxy cycloalkane. BACKGROUND

[0002] Epoxy cycloalkanes are an important class of fine chemicals, which can be used to synthesize high molecular weight prepolymers, epoxy resin curing agents, non-ionic surfactants, etc., and have a wide range of applications in the fields of petroleum, chemical industry, pesticides, daily chemicals, drugs, long carbon chain nylon synthesis, etc. Epoxy cycloalkanes are mainly prepared by oxidation of the corresponding cycloalkenes. According to the different oxidizing agents, the preparation methods of epoxy cycloalkanes include chlorohydrination method, organic peroxy acid oxidation method, hydrogen peroxide method, alkyl peroxide oxidation method, air / oxygen oxidation method, etc.

[0003] The chlorohydrination method uses cycloalkene and hypochlorous acid as raw materials to generate chlorohydrin through an addition reaction, and then the chlorohydrin reacts with lye to generate the corresponding epoxy cycloalkane. However, this method is gradually being eliminated because it produces a large amount of chlorinated wastewater in production, and hypochlorous acid can cause equipment corrosion, thereby causing pollution problems and reducing economic efficiency. The organic peroxy acid oxidation method is one of the more common methods. Organic peroxy acid is usually prepared by reacting hydrogen peroxide with the corresponding carboxylic acid. Due to the unstable chemical structure and easy decomposition of organic peroxy acid, in actual application, hydrogen peroxide and carboxylic acid are usually pre-reacted to generate peroxy acid, and then the generated peroxy acid is mixed with cycloalkene to generate epoxy cycloalkane. The alkyl peroxide oxidation method uses alkyl peroxide as an oxygen source. Compared with organic peroxy acid, alkyl peroxide has higher stability and safety and is easily soluble in organic solvents, and is commonly used as an oxidizing agent for olefin epoxidation. Alkyl peroxides such as cumene hydroperoxide (CHP) and tert-butyl hydroperoxide (TBHP) are commonly used in existing processes.

[0004] In addition, the cycloalkene oxidation method using hydrogen peroxide as an oxygen source is green and pollution-free, does not introduce impurity ions during the reaction process, and only produces water and oxygen after decomposition, does not cause equipment corrosion and environmental pollution, and has low raw material prices and strong competitiveness. The classical hydrogen peroxide direct oxidation method for preparing epoxy propane (HPPO) has achieved industrial application. There have been a large number of studies on the cycloalkene oxidation method using hydrogen peroxide as a raw material:

[0005] Patent CN105315140A relates to a preparation method of epoxy cyclododecane, which uses cyclododecene as raw material and hydrogen peroxide as oxidant in an acidic environment to obtain epoxy cyclododecane. In this method, the hydrogen peroxide used in the epoxidation reaction is in an aqueous phase, and the raw material CDEN is in an oil phase, so the mixing effect of the two phases is poor. In order to strengthen the reaction, phase transfer catalysts and metal salts are used to promote the oxidation process. Phase transfer catalysts are generally quaternary ammonium salts or organic phosphine compounds, which are expensive and increase the complexity of the reaction operation.

[0006] Patent CN113444058A provides a method for continuous oxidation of alicyclic epoxy compounds using a microchannel reactor. The method first emulsifies alicyclic olefins and hydrogen peroxide in an emulsifier to form an emulsion, and then continuously feeds the emulsion into a microreactor for oxidation reaction to obtain the corresponding target product. This method combines a micro-emulsifier and a micro-reactor to ensure the uniformity of the reaction system, avoid poor mixing, and achieve high reaction conversion and yield in the preparation of alicyclic epoxy compounds. However, the microchannel reactor has a small reaction flux, making it difficult to adapt to the production of bulk chemicals.

[0007] Patent CN112321539A provides a method for epoxidation of macrocyclic olefins using hydrogen peroxide as an oxidant. In this method, hydrogen peroxide, stabilizer, catalyst, solvent and macrocyclic olefins are put into an oxidation reactor to form a mixed solution for reaction. Although this method solves the problems of low hydrogen peroxide utilization, multiple side reactions and complex catalyst recovery in traditional processes, it has many reaction components and complex composition, making it difficult to separate.

[0008] Patent EP0033763B1 provides a preparation method for epoxy cyclododecadiene, which is mainly achieved by reacting cyclododecatriene with peroxyformic acid. Peroxyformic acid is directly formed by the reaction of formic acid and hydrogen peroxide. In this method, hydrogen peroxide is added in excess relative to cyclododecatriene, which can improve the conversion rate of raw materials but reduces the effective utilization rate of hydrogen peroxide. It is worth noting that hydrogen peroxide is unstable and can self-decompose to generate pure oxygen during use. In the production of organic matter, the enrichment of pure oxygen may pose a risk of fire or explosion to the production system. Therefore, the addition of excess hydrogen peroxide in this method increases the risk of explosion in the process and reduces the safety of production. SUMMARY

[0009] In view of the deficiencies in the prior art, the present application discloses a production process and system for epoxy cycloalkanes. The process uses cycloalkene as raw material and hydrogen peroxide as oxidant, which can promote the full reaction of hydrogen peroxide to ensure process safety and improve product yield, and is suitable for large-scale industrial production.

[0010] To achieve the above technical purposes, in one aspect, the present application provides a process for producing an epoxy cycloalkane, comprising the following steps

[0011] an oxidation step, wherein the oxidation step is carried out in N reactors connected in series, the outlet of the previous reactor is connected to the inlet of the next reactor; the raw material cycloalkene and the solvent are input into the inlet of the first reactor, and the oxidant hydrogen peroxide is divided into N-1 parts and added into the first to the N-1 reactors; the first material after the oxidation reaction is output from the outlet of the last reactor, wherein N is at least 2;

[0012] a first refining step, wherein the first material is separated into the solvent, the unreacted cycloalkene and the first heavy component by a first distillation operation, to obtain a second material;

[0013] a hydrogenation step, wherein the second material is subjected to a hydrogenation reaction under the action of a hydrogenation catalyst to obtain a third material;

[0014] a second refining step, wherein the third material is sequentially subjected to a gas-liquid separation to discharge the unreacted hydrogen, a second distillation operation to separate the light component and the second heavy component, to obtain a high-purity epoxy cycloalkane product;

[0015] In the process, the unreacted cycloalkene separated in the first refining step is returned to the oxidation step; the molar ratio of the cycloalkene to the hydrogen peroxide in the hydrogen peroxide is (2-7):1.

[0016] In the above technical solution, the raw material cycloalkene is subjected to an epoxidation reaction of the olefin double bond in the oxidation step, and the raw material cycloalkene is subjected to an oxidation reaction with hydrogen peroxide to obtain an epoxy primary product, and the epoxy primary product is subjected to a hydrogenation saturation reaction of the remaining double bond in the hydrogenation step to form a saturated carbon-carbon bond. In the above technical solution, multiple technical features are provided to improve the effective utilization rate of hydrogen peroxide, improve the product yield, and promote the complete reaction of hydrogen peroxide:

[0017] First, the oxidation reaction step is carried out in multiple reactors, and the raw material cycloalkene is input into the first reactor, and the oxidant hydrogen peroxide is input into each reactor (except the last reactor) in batches, and the material after the reaction of the previous reactor is input into the next reactor to continue the oxidation reaction with the newly input hydrogen peroxide, so that the raw material cycloalkene in each reactor is excessive relative to the input hydrogen peroxide, thereby improving the effective utilization rate of hydrogen peroxide and effectively promoting the complete reaction of hydrogen peroxide.

[0018] Further, the hydrogen peroxide is only input into the first to the N-1th reactors, and the last reactor is not added with new oxidant, but the oxidation reaction in the N-1th reactor is continuously strengthened, so that the condition that the hydrogen peroxide in the first material is not completely reacted can be avoided, and the condition that the oxygen generated by the decomposition of the hydrogen peroxide not completely reacted in the subsequent process causes a safety accident can be further avoided.

[0019] Further, the research and development team of the present application finds that the molar ratio of the raw material cycloalkene and the hydrogen peroxide directly affects the effective utilization rate of the hydrogen peroxide through a large number of small test exploration experiments, and the effective utilization rate of the hydrogen peroxide can be effectively improved to be more than 98% by controlling the molar ratio of the cycloalkene and the hydrogen peroxide to be not less than 2 (the stoichiometric relationship of the two is 1) ; based on the finding, the molar ratio of the cycloalkene and the hydrogen peroxide in the above technical solution is (2-7) : 1, so that the complete reaction of the hydrogen peroxide can be promoted by excessive addition of the raw material cycloalkene at the beginning of the oxidation process; further, in order to improve the product yield under the premise of excessive addition of the cycloalkene relative to the hydrogen peroxide, the above technical solution further sets the technical feature of recycling the raw material cycloalkene, that is, the unreacted cycloalkene separated in the first refining process is returned to the oxidation process, so that the excessive cycloalkene can continue to participate in the reaction as raw material, and the recycling of the raw material reduces the production cost and improves the raw material conversion rate, so that the production process of the present application realizes high hydrogen peroxide utilization rate and high product yield at the same time.

[0020] Further, the above technical solution sets the refining process after the oxidation process and the hydrogenation process, respectively, and the high-purity epoxy cycloalkane product is obtained through step-by-step refining, the process flow is simple, the operability is strong, and the process is suitable for industrial production.

[0021] In a further example of the present application, the addition amount of the cycloalkene and the hydrogen peroxide is explored and optimized. Optionally, the molar ratio of the cycloalkene and the hydrogen peroxide is (2-3) : 1, so that the utilization rate of the hydrogen peroxide is better.

[0022] In a further example of the present application, the control conditions of the oxidation process are explored and optimized. Optionally, the reaction temperature of the oxidation process is 80-110℃, and the pressure is 3000-6000Pa; in the oxidation process, the residence time of the reactant in each reactor is 1-3h, so that the reaction progress is controlled and the process production efficiency is improved.

[0023] It should be noted that the present application does not limit the catalyst used in the oxidation process, and the present application controls the process flow and the ratio of raw materials and oxidizing agent to promote the complete reaction of hydrogen peroxide and obtain high product yield. Those skilled in the art can select a suitable catalyst through non-creative labor, such as a TS-1 type titanium silicon analysis screen catalyst, and the technical solutions formed thereby are within the scope of the present application.

[0024] It should be noted that the present application does not limit the specific structure of each reaction kettle in the oxidation process. In further examples of the present application, the reaction kettle can be configured with a jacket or an internal coil to control the reaction temperature, and the oxidation reaction can be carried out under stirring conditions. Those skilled in the art can set other technical features that promote temperature and pressure control through non-creative labor, and the technical solutions formed thereby are within the scope of the present application.

[0025] It should be noted that the present application is not limited to the distribution amount and addition rate of the oxidizing agent in the N-1 reaction kettles. The total amount of the oxidizing agent can be uniformly input into the N-1 reaction kettles to facilitate overall control, or the addition amount can be gradually reduced to match the decreasing amount of raw material cycloalkene from the first reaction kettle to the N-1 reaction kettle, or the hydrogen peroxide feeding of each kettle can be adjusted according to the actual working condition. In the actual process, the addition of the oxidizing agent can be monitored and controlled by a flow meter.

[0026] In further examples of the present application, a catalyst filtration process is provided after the oxidation process. A membrane filtration device or other filtration device can be used to filter and separate the catalyst entrained in the first material to improve the efficiency of the subsequent refining process.

[0027] In further examples of the present application, the concentration of hydrogen peroxide is 25-70 wt%, preferably 30-50 wt%. By optimizing the concentration of hydrogen peroxide, the reaction can be ensured to proceed along a specific path, the reaction rate and efficiency can be controlled, and the operability of the process can be improved.

[0028] The present application has wide applicability and is suitable for preparing corresponding epoxy cycloalkanes from various cycloalkenes with different carbon atom numbers. In further examples of the present application, the cycloalkene can be a cycloalkene with 8-16 carbon atoms, and further can be a cycloalkene with 12 carbon atoms. The present application embodiment shows the process of preparing corresponding epoxy cycloalkanes from cycloalkenes with different carbon atom numbers.

[0029] The kind of the solvent in the production process is not limited, and in further examples of the present application, C5-C8 alcohol can be selected, so as to promote the compatibility of the raw material cycloalkene and hydrogen peroxide, promote the efficient reaction, and improve the production efficiency.

[0030] In further examples of the present application, the amount of the solvent is optimized. Optionally, the mass ratio of the cycloalkene to the solvent is 1:(2-4), and the optimization of the amount of the solvent in the reaction medium improves the process stability and controllability.

[0031] In further examples of the present application, the number of reaction kettles in the oxidation process is optimized. Optionally, the number N of reaction kettles is a natural number of 2-8, preferably a natural number of 3-6, which is beneficial to promote the full use of hydrogen peroxide in the oxidation process, reduce the equipment investment cost of the production process, and improve the economic benefit of the production process.

[0032] In further examples of the present application, the amount of hydrogen added in the hydrogenation process is optimized. Optionally, the molar ratio of the second material to hydrogen in the hydrogenation process is 1:(2-4), and the input of excess hydrogen improves the product yield of the overall process.

[0033] In further examples of the present application, the control conditions of the hydrogenation process are optimized. Optionally, the reaction temperature of the hydrogenation process is 80-100 DEG C, and the reaction pressure is 0.1-1 MPa; optionally, the feed airspeed of the second material in the hydrogenation process is 0.5-2 h -1 .

[0034] The kind of the catalyst used in the hydrogenation process in the production process is not limited, and those skilled in the art can select a suitable type of hydrogenation catalyst in the actual process. In further optional examples of the present application, the catalyst used in the hydrogenation process can be a supported catalyst comprising an active component and a carrier, and the active component can comprise one or more of Pt, Pd, and Ru, which can improve the hydrogenation efficiency. It should be noted that the specific preparation process of the catalyst used in the present application can be selected as follows: first, load the nitrate or chloride salt of the noble metal on the carrier, then dry and calcine to form the catalyst product, at this time the noble metal exists in the form of oxidation state; load the catalyst product into the reactor, and perform pre-reduction operation using hydrogen before use to reduce the oxidation state to the metal state. Optionally, the carrier comprises one or more of alumina, silica, and magnesia.

[0035] In a further example of the present application, the solvent separated in the first refining process is returned to the oxidation process after being purified by rectification, so as to reduce the process cost through solvent recycling.

[0036] In a further example of the present application, the hydrogen gas separated in the gas-liquid separation of the second refining process is returned to the hydrogenation process, so as to avoid raw material waste and improve raw material utilization.

[0037] In a further example of the present application, the second heavy component separated in the second refining process is returned to the first refining process, so as to recycle the target product in the second heavy component and improve product yield.

[0038] In a further example of the present application, the control conditions of the first rectification operation and the second rectification operation are explored and optimized. Optionally, the first rectification operation includes a first-stage rectification tower rectification, a second-stage rectification tower rectification, and a third-stage rectification tower rectification; further optionally, the first-stage rectification tower rectification has a tower top temperature of 50-90°C, a tower bottom temperature of 150-200°C, a tower top pressure of 0.5-1 bar, and a reflux ratio of 0.5-1; further optionally, the second-stage rectification tower rectification has a tower top temperature of 100-140°C, a tower bottom temperature of 150-200°C, a tower top pressure of 0.1-0.5 bar, and a reflux ratio of 1-5; further optionally, the third-stage rectification tower rectification has a tower top temperature of 100-150°C, a tower bottom temperature of 160-210°C, a tower top pressure of 0.01-0.1 bar, and a reflux ratio of 5-20. Optionally, the second rectification operation includes a fourth-stage rectification tower rectification and a fifth-stage rectification tower rectification; further optionally, the fourth-stage rectification tower rectification has a tower top temperature of 90-120°C, a tower bottom temperature of 150-180°C, a tower top pressure of 0.01-0.1 bar, and a reflux ratio of 20-30; further optionally, the fifth-stage rectification tower rectification has a tower top temperature of 120-140°C, a tower bottom temperature of 150-180°C, a tower top pressure of 0.01-0.1 bar, and a reflux ratio of 5-20. Through optimization of the control conditions, the separation efficiency can be improved, product loss can be avoided, and product purity can be improved.

[0039] In another aspect, the present application provides an epoxy cycloalkane production system, which comprises the following units:

[0040] The oxidation unit comprises N reaction kettles connected in series, and the outlet of the previous reaction kettle is connected to the inlet of the next reaction kettle, wherein the first reaction kettle is connected to the raw material cycloalkene input pipe and the solvent input pipe, the first to N-1 reaction kettles are connected to the hydrogen peroxide input pipe, and the N reaction kettle is provided with an outlet for outputting the material after the oxidation reaction;

[0041] The first refining unit comprises at least one distillation column, and the outlet of the N reaction kettle is connected to the inlet of the first distillation column of the first refining unit;

[0042] The hydrogenation unit comprises a hydrogenation reactor, and the overhead outlet of the last distillation column of the first refining unit is connected to the raw material inlet of the hydrogenation reactor, and the hydrogenation reactor is further connected to a hydrogen input pipe;

[0043] The second refining unit comprises a gas-liquid separation device and at least one distillation column, the outlet of the hydrogenation reactor is connected to the inlet of the gas-liquid separation device, the liquid phase outlet of the gas-liquid separation device is connected to the inlet of the first distillation column of the second refining unit, and the overhead outlet of the last distillation column of the second refining unit outputs a high-purity epoxy cycloalkane product.

[0044] It should be noted that the type and structure of the reactor used in the hydrogenation process in the production process of the present application are not limited, and a fixed bed reactor can be selected, and further a fixed bed reactor with tubes can be selected, and those skilled in the art can select a suitable hydrogenation reactor in the actual process, and the technical solutions formed thereby are within the protection scope of the present application. The specific structure of the gas-liquid separation device is not limited in the present application, and those skilled in the art can select a suitable device for gas-liquid separation of the material after hydrogenation according to the specific working condition, and the technical solutions formed thereby are within the protection scope of the present application. In addition, those skilled in the art can understand that the specific structure, number, etc. of the distillation columns of the first refining unit and the second refining unit are not limited, and can be set according to the actual situation.

[0045] Further, N is a natural number of 2-8, preferably a natural number of 3-6.

[0046] Further, a filtering device is arranged on the pipeline connecting the N reaction kettle and the first distillation column, for separating the catalyst in the material after the oxidation reaction, so as to facilitate subsequent separation and purification. Further, a filtering device is arranged on the pipeline connecting two adjacent reaction kettles. It should be noted that the specific structure of the filtering device is not limited in the present application, and those skilled in the art can select a suitable device to filter and separate the catalyst entrained in the material input by the reaction kettle according to the specific working condition, for example, the filtering device can be a filter membrane, and the technical solutions formed thereby are within the protection scope of the present application.

[0047] Further, a solvent purification rectifying tower is further included, when the first refining unit includes at least two rectifying towers, the overhead outlet of the first rectifying tower is connected with the feed inlet of the solvent purification rectifying tower, and the bottom outlet of the solvent purification rectifying tower is connected with the feed inlet of the first reaction kettle, so that the solvent is recycled and reused.

[0048] Further, a solvent purification rectifying tower is further included, when the first refining unit includes at least three rectifying towers, the overhead outlet of the first rectifying tower is connected with the feed inlet of the solvent purification rectifying tower, and the bottom outlet of the solvent purification rectifying tower is connected with the feed inlet of the first reaction kettle, so that the solvent is recycled and reused; the overhead outlet of the rectifying tower other than the first and last rectifying towers is connected with the feed inlet of the first reaction kettle, so that the raw material cycloalkene is recycled and used, and the product yield is improved.

[0049] Further, the gas phase outlet of the gas-liquid separation device is connected with the hydrogen inlet of the hydrogenation reactor, so that the raw material hydrogen is recycled and used, and the raw material utilization rate is improved.

[0050] Further, the bottom outlet of the last rectifying tower of the second refining unit is connected with the feed inlet of the third rectifying tower, so that the product is recycled and recovered, and the product yield is improved.

[0051] Further, the first refining unit includes a first rectifying tower, a second rectifying tower and a third rectifying tower connected in sequence, the discharge outlet of the Nth reaction kettle is connected with the feed inlet of the first rectifying tower, and the overhead outlet of the third rectifying tower is connected with the raw material inlet of the hydrogenation reactor.

[0052] Further, the second refining unit includes a fourth rectifying tower and a fifth rectifying tower connected in sequence.

[0053] Compared with the prior art, the present application has the following beneficial effects:

[0054] The production process of the present application takes cycloalkene as a raw material and hydrogen peroxide as an oxidant, and high-purity epoxy cycloalkane products are obtained through an oxidation process, a first refining process, a hydrogenation process and a second refining process. The present application sets multiple technical features for improving the effective utilization rate of hydrogen peroxide, improving the product yield, and promoting the complete reaction of hydrogen peroxide, including adding excess cycloalkene relative to hydrogen peroxide, combining specific reaction equipment, hydrogen peroxide addition method and raw material recycling, realizing the effective utilization of hydrogen peroxide and full utilization. It is a safe, high-yield process suitable for large-scale industrial production. The equipment investment of the epoxy cycloalkane production system of the present application is low, safe and efficient, and has strong operability, which is suitable for industrial production. BRIEF DESCRIPTION OF DRAWINGS

[0055] The accompanying drawings, which form a part of this specification, are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification. The drawings illustrate an exemplary embodiment of the application and, together with the description, serve to explain the application. In the drawings:

[0056] Figure 1 shows a system structure and process flow diagram for producing epoxy cycloalkanes according to the present application.

[0057] Figure 2 shows a detailed structure of the oxidation unit in Figure 1.

[0058] In the above drawings, the following reference numerals are used: 1 - oxidation unit, 11 - reaction kettle, 12 - raw material cycloalkene input pipe, 13 - hydrogen peroxide input pipe, 14 - solvent input pipe, 15 - first material mixer, 111 - first reaction kettle, 112 - N-1th reaction kettle, 113 - Nth reaction kettle; 2 - first refining unit, 21 - first distillation column, 22 - second distillation column, 23 - third distillation column; 3 - hydrogenation unit, 31 - hydrogenation reactor, 32 - hydrogen input pipe, 33 - second material mixer; 4 - second refining unit, 41 - gas-liquid separation device, 42 - fourth distillation column, 43 - fifth distillation column; 5 - filtration device; 6 - solvent purification column; S1-1 raw material cycloalkene, S1-2 solvent, S1-3 hydrogen peroxide, S1-4 first material, S1-5 preliminary refined stream, S1-6 raw material and solvent mixture stream, S1-7 reaction kettle gas phase product; S2-1 crude solvent, S2-2 stream after separation of solvent, S2-3 unreacted cycloalkene, S2-4 material after separation of solvent and unreacted raw material, S2-5 second material, S2-6 first heavy component; S3-1 third material, S3-2 gas phase, S3-3 newly input process hydrogen, S3-4 mixed hydrogen; S4-1 liquid phase, S4-2 light component, S4-3 material after separation of light component, S4-4 second heavy component, S4-5 high-quality epoxy cycloalkane product. DETAILED DESCRIPTION

[0059] In order to facilitate the understanding of the present application, a more comprehensive description of the present application will be given below, and a preferred embodiment of the present application is given. However, it should be understood that these embodiments are only used for more detailed description, and should not be understood as limiting the present application in any form, i.e. not intended to limit the protection scope of the present application.

[0060] Unless otherwise defined, the technical terms used in the following examples have the same meanings as generally understood by those skilled in the art to which the present application pertains. The test reagents used in the following examples, unless otherwise specified, are conventional biochemical reagents; and the experimental methods, unless otherwise specified, are conventional methods.

[0061] It should be noted that in the description of the preferred embodiment, unless otherwise explicitly specified and limited, the terms "first", "second", "third", "fourth", "fifth", "sixth", "primary", "secondary", "tertiary" are only for the purpose of description, and the above terms in the present application can be understood according to the specific circumstances by those skilled in the art, and therefore cannot be understood as a limitation on the present application.

[0062] Exploration example

[0063] The present exploration example takes the reaction of preparing epoxy cyclododecadiene (OCDT) by oxidizing cyclododecatriene (CDT) with hydrogen peroxide as an example, and explores the influence of adding cycloalkene and hydrogen peroxide on the utilization rate of hydrogen peroxide. The specific reaction is as follows:

[0064] After the reaction is completed, the CDT and OCDT contents in the reaction material are detected by gas chromatography to obtain the raw material conversion rate, and further to obtain the amount of hydrogen peroxide actually participating in the cycloalkene oxidation reaction; the residual amount of hydrogen peroxide is determined by iodometric method, and then the total consumption of hydrogen peroxide is calculated combined with the addition amount of hydrogen peroxide. The effective utilization rate of hydrogen peroxide is defined as the ratio of the amount of hydrogen peroxide participating in the olefin oxidation to the total consumption of hydrogen peroxide.

[0065] Exploration example 1

[0066] 300g of tert-butyl alcohol solvent and 20g of TS molecular sieve were added to the reactor and stirred uniformly. 50g of CDT and 21g of hydrogen peroxide (50%) were slowly added to the above reactor by two peristaltic pumps, respectively, and the molar ratio of CDT to hydrogen peroxide was 1:1. The feeding time of the two peristaltic pumps was controlled at 5h, and after the feeding was completed, the reaction was completed after stirring for 1h. Stirring was maintained throughout the reaction, and the temperature was controlled at 80℃ and the pressure was controlled at 6000pa. After the reaction was completed, the catalyst was separated by filtration to obtain the final reaction liquid. The reaction liquid was analyzed: the CDT conversion rate was analyzed by gas chromatography, the residual amount of hydrogen peroxide in the reaction liquid was determined by iodometric method to be 0.59%, and the final effective utilization rate of hydrogen peroxide was calculated. The final CDT conversion rate was 70.5%, and the effective utilization rate of hydrogen peroxide was 78.8%.

[0067] Exploration example 2

[0068] Into a reactor, 300 g of t-butyl alcohol solvent and 20 g of TS molecular sieve were added and stirred uniformly. 50 g of CDT and 15.8 g of hydrogen peroxide (50%) were slowly added dropwise into the above reactor by two peristaltic pumps, respectively, wherein the molar ratio of CDT to hydrogen peroxide was 1.3:1. The feeding time of the two peristaltic pumps was controlled at 5 h, and after the feeding was completed, the reaction was ended after stirring for 1 h. The stirring was maintained during the reaction, and the temperature was controlled at 80°C, and the pressure was controlled at 6000 pa. After the reaction was completed, the catalyst was separated by filtration to obtain the final reaction solution. The reaction solution was analyzed: the CDT conversion rate was analyzed by gas chromatography, the residual amount of hydrogen peroxide in the reaction solution was determined by iodimetry to be 0.22%, and the effective utilization rate of hydrogen peroxide was calculated. The final CDT conversion rate was 61.5%, and the effective utilization rate of hydrogen peroxide was 86.1%.

[0069] Exploration Example 3

[0070] Into a reactor, 300 g of t-butyl alcohol solvent and 20 g of TS molecular sieve were added and stirred uniformly. 50 g of CDT and 15.8 g of hydrogen peroxide (50%) were slowly added dropwise into the above reactor by two peristaltic pumps, respectively, wherein the molar ratio of CDT to hydrogen peroxide was 1.3:1. The feeding time of the two peristaltic pumps was controlled at 5 h, and after the feeding was completed, the reaction was ended after stirring for 1 h. The stirring was maintained during the reaction, and the temperature was controlled at 80°C, and the pressure was controlled at 6000 pa. After the reaction was completed, the catalyst was separated by filtration to obtain the final reaction solution. The reaction solution was analyzed: the CDT conversion rate was analyzed by gas chromatography, the residual amount of hydrogen peroxide in the reaction solution was determined by iodimetry to be 0.22%, and the effective utilization rate of hydrogen peroxide was calculated. The final CDT conversion rate was 61.5%, and the effective utilization rate of hydrogen peroxide was 86.1%.

[0071] Exploration Example 4

[0072] Into a reactor, 300 g of t-butyl alcohol solvent and 20 g of TS molecular sieve were added and stirred uniformly. 50 g of CDT and 15.8 g of hydrogen peroxide (50%) were slowly added dropwise into the above reactor by two peristaltic pumps, respectively, wherein the molar ratio of CDT to hydrogen peroxide was 1.3:1. The feeding time of the two peristaltic pumps was controlled at 5 h, and after the feeding was completed, the reaction was ended after stirring for 1 h. The stirring was maintained during the reaction, and the temperature was controlled at 80°C, and the pressure was controlled at 6000 pa. After the reaction was completed, the catalyst was separated by filtration to obtain the final reaction solution. The reaction solution was analyzed: the CDT conversion rate was analyzed by gas chromatography, the residual amount of hydrogen peroxide in the reaction solution was determined by iodimetry to be 0.22%, and the effective utilization rate of hydrogen peroxide was calculated. The final CDT conversion rate was 61.5%, and the effective utilization rate of hydrogen peroxide was 86.1%.

[0073] As known in the art, hydrogen peroxide is considered to have fully participated in the reaction when its effective utilization rate is greater than 95%, i.e. the hydrogen peroxide has been completely reacted. Comparative analysis of Examples 1-4 shows that the effective utilization rate of hydrogen peroxide can be increased to more than 98% by controlling the ratio of olefin to hydrogen peroxide to be not less than 2.

[0074] Example 1

[0075] A production system of an epoxy cycloalkane is shown in Fig. 1, which comprises an oxidation unit 1, a first refining unit 2, a hydrogenation unit 3 and a second refining unit 4, wherein,

[0076] The oxidation unit 1, in combination with Fig. 2, comprises N reaction kettles 11 connected in series, and the discharge port of the last reaction kettle 11 is connected to the feed port of the next reaction kettle 11, wherein the first reaction kettle 111 is connected to a raw material cycloalkene input pipe 12 and a solvent input pipe 14, the first to N-1 reaction kettles 112 are connected to a hydrogen peroxide input pipe 13, and the N reaction kettle 113 is provided with a discharge port for discharging the material after the oxidation reaction.

[0077] Optionally, N is a natural number of 2-8, and further optionally a natural number of 3-6.

[0078] The first refining unit 2 comprises a first distillation column 21, a second distillation column 22 and a third distillation column 23, and the discharge port of the N reaction kettle 113 is connected to the feed port of the first distillation column 21; the first distillation column 21 is provided with a top outlet and a bottom outlet, and the bottom outlet is connected to the feed port of the second distillation column 22; the second distillation column 22 is provided with an outlet and a bottom outlet, and the bottom outlet is connected to the feed port of the third distillation column 23; and the third distillation column 23 is provided with a top outlet and a bottom outlet.

[0079] Optionally, a filter device 5 is arranged on the pipeline connecting the N reaction kettle 113 and the first distillation column 21. Further optionally, a filter device 5 is arranged on the pipeline connecting two adjacent reaction kettles.

[0080] Optionally, the top outlet of the first distillation column 21 is connected to the feed port of a solvent purification column 6, and the bottom of the solvent purification column 6 is connected to the solvent input pipe 14 and further connected to the oxidation unit 1. Further optionally, a pipeline connecting the oxidation unit and the feed port of the solvent purification column is arranged for inputting the gas phase generated in each reaction kettle during the reaction into the solvent purification column for distillation.

[0081] Optionally, the top outlet of the second distillation column 22 is connected to the first reaction kettle 111.

[0082] Further optionally, the oxidation unit 1 further comprises a first material mixer 15, the solvent input pipe 14 is connected to the feed inlet of the first reactor 111 through the first material mixer 15; the overhead of the second rectifying column 22 is connected to the feed inlet of the first reactor 111 through the first material mixer 15; the raw material cyclic olefin input pipe 12 is connected to the feed inlet of the first reactor 111 through the first material mixer 15.

[0083] The hydrogenation unit 3 comprises a hydrogenation reactor 31, the overhead of the third rectifying column 23 is connected to the raw material inlet of the hydrogenation reactor 31 through a pipeline, and the hydrogenation reactor 31 is further connected to a hydrogen input pipe 32.

[0084] The second refining unit 4 comprises a gas-liquid separation device 41, a fourth rectifying column 42 and a fifth rectifying column 43, the outlet of the hydrogenation reactor 31 is connected to the feed inlet of the gas-liquid separation device 41 through a pipeline, and the liquid phase outlet thereof is connected to the feed inlet of the fourth rectifying column 42; the fourth rectifying column 42 is provided with an overhead outlet and a column outlet, and the column outlet is connected to the feed inlet of the fifth rectifying column 43 through a pipeline; the high-purity epoxy cycloalkane product is output from the overhead outlet of the rectifying column.

[0085] Optionally, the gas phase outlet of the gas-liquid separation device 41 is connected to the hydrogen inlet of the hydrogenation reactor 31 through a pipeline.

[0086] Further optionally, the gas phase outlet of the gas-liquid separation device 41 is connected to the hydrogen inlet of the hydrogenation reactor 31 through a second material mixer 33, and the hydrogen input pipe 32 of the system is connected to the second material mixer 33.

[0087] Optionally, the column outlet of the fifth rectifying column 43 is connected to the feed inlet of the third rectifying column 23 through a pipeline.

[0088] Embodiment 2

[0089] A production process of an epoxy cycloalkane, which is based on the production system of the epoxy cycloalkane shown in embodiment 1, and specifically, the production process comprises:

[0090] The oxidation process is carried out in N reactors 11 connected in series, and the outlet of the previous reactor 11 is connected to the inlet of the next reactor 11; the raw material cyclic olefin S1-1 and the solvent S1-2 are input into the feed inlet of the first reactor 111, and the oxidant hydrogen peroxide S1-3 is divided into N-1 parts and added into the first reactor to the N-1 reactor 112; the first material S1-4 after the oxidation reaction is output from the outlet of the last reactor.

[0091] Optionally, the molar ratio of the raw material cyclic olefin S1-1 to the hydrogen peroxide S1-3 in the oxidation process is (3-2):1.

[0092] Optionally, the reaction temperature of the oxidation step is 80-110℃, and the pressure is 3000-6000 Pa; in the oxidation step, the residence time of the reaction material in each reactor 11 is 1-3 h.

[0093] Optionally, the oxidant is an aqueous solution of hydrogen peroxide, and the concentration is 25-70 wt%, preferably 30-50 wt%.

[0094] Optionally, the cyclic olefin is a cyclic mono-olefin or a cyclic poly-olefin with 8-16 carbon atoms; further optionally, a cyclic mono-olefin or a cyclic poly-olefin with 12 carbon atoms.

[0095] Optionally, the solvent S1-2 is a C5-C8 alcohol.

[0096] Optionally, the mass ratio of the raw material cyclic olefin S1-1 to the solvent S1-2 is 1:(2-4).

[0097] The first material S1-4 prepared in the oxidation step includes unreacted cyclic olefin S2-3, solvent, primary epoxy product, and heavy components, etc. In the present embodiment, the first material S1-4 is separated and purified in the subsequent first refining step.

[0098] Optionally, after the first material S1-4 is filtered through the filtering device 5, the catalyst entrained in the first material S1-4 is separated and filtered to obtain a preliminary refined stream S1-5, which is input into the subsequent refining step.

[0099] The first refining step: the first material S1-4 is separated by the first distillation operation to separate the solvent, unreacted cyclic olefin S2-3, and first heavy component S2-6, to obtain a second material S2-5.

[0100] Optionally, the first distillation operation includes primary distillation column distillation, secondary distillation column distillation, and tertiary distillation column distillation.

[0101] Further optionally, the primary distillation column distillation is performed in the first distillation column 21, the overhead temperature is 50-90℃, the bottom temperature is 150-200℃, the overhead pressure is 0.5-1 bar, and the reflux ratio is 0.5-1. After the first material S1-4 is subjected to the primary distillation column distillation, the crude solvent S2-1 is collected from the overhead of the first distillation column 21, and the stream S2-2 after separating the solvent is collected from the bottom of the first distillation column 21, which is input into the second distillation column 22 for secondary distillation column distillation. Further optionally, the overhead temperature of the primary distillation column distillation is 50-90℃, the bottom temperature is 150-200℃, the overhead pressure is 0.5-1 bar, and the reflux ratio is 0.5-1.

[0102] Further optionally, the crude solvent S2-1 separated from the first refining process is purified in the solvent purification column 6, and the solvent S1-2 is collected from the bottom of the solvent purification column 6 and returned to the oxidation process. Further optionally, the top temperature of the solvent purification column is 30-60°C, the bottom temperature is 90-120°C, the top pressure is 0.5-1 bar, and the reflux ratio is 20-30; water is collected from the top of the solvent purification column 6 and input into the subsequent wastewater treatment process. Further optionally, the gaseous product S1-7 generated from the reaction kettle in the oxidation unit is input into the solvent purification column for rectification to recover the solvent therein.

[0103] Further optionally, the secondary rectification is performed in the second rectification column 22, the top temperature of the second rectification column 22 is 100-140°C, the bottom temperature is 150-200°C, the top pressure is 0.1-0.5 bar, and the reflux ratio is 1-5. Unreacted cycloolefin S2-3 is collected from the top of the second rectification column 22, and the part of the material is recycled to the oxidation process; the material S2-4 after separation of the solvent and unreacted raw material is collected from the bottom of the second rectification column 22 and input into the third rectification column 23 for tertiary rectification.

[0104] Further optionally, the raw material cycloolefin S1-1, the solvent S1-2 and the unreacted cycloolefin S2-3 are mixed in the first material mixer 15 to obtain a raw material and solvent mixture S1-6, which is input into the oxidation process.

[0105] Further optionally, the tertiary rectification is performed in the third rectification column 23, the top temperature of the third rectification column 23 is 100-150°C, the bottom temperature is 160-210°C, the top pressure is 0.01-0.1 bar, and the reflux ratio is 5-20. The second material S2-5 containing the primary epoxy product is collected from the top of the third rectification column 23, and the second material S2-5 is input into the subsequent hydrogenation process; the first heavy component S2-6 collected from the bottom of the third rectification column 23 is input into the subsequent waste liquid treatment process.

[0106] The hydrogenation process: the second material S2-5 is reacted in the hydrogenation reactor 31 under the action of the hydrogenation catalyst to obtain the third material S3-1.

[0107] Optionally, the molar ratio of the second material S2-5 to hydrogen in the hydrogenation process is 1:(2-4).

[0108] Optionally, the reaction temperature of the hydrogenation process is 80-100°C, and the reaction pressure is 0.1-1 MPa.

[0109] Optionally, the feed space velocity of the second material S2-5 in the hydrogenation process is 0.5-2 h -1 .

[0110] Optionally, the catalyst of the hydrogenation process is a supported catalyst comprising an active component and a support, the active component comprising one or more of Pt, Pd, Ru. Further optionally, the support comprises one or more of alumina, silica, magnesia.

[0111] The third material S3-1 obtained after the hydrogenation reaction comprises unreacted hydrogen, light components, heavy components and the target product, and the part of the material is input into the second refining process for separation and purification.

[0112] The second refining process: the third material S3-1 is sequentially subjected to gas-liquid separation to discharge unreacted hydrogen, and is subjected to second rectification operation to separate light components and second heavy components S4-4, to obtain high-purity epoxide cycloalkane products.

[0113] Optionally, in the second refining process, the gas phase S3-2 is subjected to gas-liquid separation, the gas phase S3-2 is unreacted hydrogen, which is returned to the hydrogenation process, and the liquid phase S4-1 obtained by gas-liquid separation is input into the second rectification operation. Further optionally, the unreacted hydrogen separated in the second refining process and the hydrogen S3-3 newly input into the process are mixed to obtain mixed hydrogen S3-4, which is input into the hydrogenation process.

[0114] Optionally, the second rectification operation comprises four-stage rectification column rectification and five-stage rectification column rectification.

[0115] Further optionally, the four-stage rectification column rectification is carried out in the fourth rectification column 42, the overhead temperature is 90-120℃, the bottom temperature is 150-180℃, the overhead pressure is 0.01-0.1bar, and the reflux ratio is 20-30. The liquid phase S4-1 after gas-liquid separation is separated and purified by the fourth rectification column 42, the light components S4-2 are collected from the overhead of the fourth rectification column 42, and the part of the components is discharged from the boundary zone; the material S4-3 after separation of the light components is collected from the bottom of the fourth rectification column 42 and input into the fifth rectification column 43 for five-stage rectification column rectification.

[0116] Further optionally, the five-stage rectification column rectification has an overhead temperature of 120-140℃, a bottom temperature of 150-180℃, an overhead pressure of 0.01-0.1bar, and a reflux ratio of 5-20. High-quality epoxide cycloalkane products S4-5 are collected from the overhead of the fifth rectification column 43, and the second heavy components S4-4 containing the target product are collected from the bottom of the fifth rectification column 43. Optionally, the second heavy components S4-4 separated in the second refining process are returned to the first refining process; further optionally, the second heavy components S4-4 are returned to the three-stage rectification column rectification.

[0117] Example 3

[0118] Based on the production process of epoxy cycloalkane shown in Example 2, this embodiment shows a production process of epoxy cycloalkane under certain conditions. It should be noted that this embodiment only demonstrates the optimal conditions and does not limit the scope of protection of the present application.

[0119] A production process of epoxy cycloalkane, taking a 1200 tons / year epoxy cyclododecane production system as an example, including

[0120] Oxidation process: the reactor is 4 reactors 11 in series, the raw material is cyclododecatriene 1000 kg / h, the solvent is octanol 2000 kg / h, both are mixed and then added from the inlet of the first reactor 111; 50wt% hydrogen peroxide 60 kg / h, divided into 3 equal parts, added into the first three reactors respectively; the temperature of oxidation reaction is 90℃, the pressure is 6000pa, the residence time of single-pot material is 1.5h, the catalyst is TS-1 catalyst, the solid content of titanium silicalite catalyst in each reactor is controlled at 20%; after the reaction is completed, the water content in the first material S1-4 is 1.49%, the solvent octanol is 65.18%, the cyclododecatriene is 27.94%, the epoxy primary product (including epoxy cyclododecane mono / diene, etc.) is 5.25%, and the others are 0.14%; the effective utilization rate of hydrogen peroxide in the reaction is 99.5%, and the detected hydrogen peroxide in the reaction material is basically reacted (hydrogen peroxide content is less than 0.05wt%). The first material S1-4 flows out from the bottom of the fourth reactor, is filtered by the membrane filtration device 5, and then enters the subsequent first refining process.

[0121] The first refined process: the first material S1-4 enters the first rectifying tower 21 at room temperature for separation, the top temperature of the first rectifying tower 21 is 50℃, the bottom temperature is 150℃, the top pressure is 0.5bar, and the reflux ratio is 1; the crude solvent S2-1 containing water, light components and organic solvents is separated from the top of the first rectifying tower 21, which enters the solvent purification tower 6 for separation. The top temperature of the solvent purification tower 6 is 30℃, the bottom temperature is 90℃, the top pressure is 0.5bar, and the reflux ratio is 20; the waste water 89.4kg / h is separated from the top of the solvent purification tower 6 and sent out of the boundary, and the solvent octanol 1955kg / h is obtained by rectifying the bottom of the tower, of which the concentration of octanol is 99.95%, and it is recycled back to the oxidation process to continue the reaction. The bottom stream of the first rectifying tower 21 continues to enter the second rectifying tower 22 for separation and purification, wherein the top temperature of the second rectifying tower 22 is 102℃, the bottom temperature is 154℃, the top pressure is 0.5bar, and the reflux ratio is 5; the unreacted cyclododecatriene with a purity of 99.88% is separated from the top of the second rectifying tower 22 and returned to the reaction kettle 11 for continuous reaction; the bottom material of the second rectifying tower 22 enters the third rectifying tower 23 for further separation and purification, wherein the top temperature of the third rectifying tower 23 is 110℃, the bottom temperature is 161℃, the top pressure is 0.1bar, and the reflux ratio is 20; the second material S2-5 mainly containing the primary product of epoxy is separated from the top of the third rectifying tower 23, with a flow rate of 159.7kg / h, which is input into the hydrogenation process for reaction, and the first heavy component S2-6 collected from the bottom of the third rectifying tower 23 is a heavy component impurity, which is mainly tar and will be discharged out of the boundary.

[0122] The hydrogenation process: the second material S2-5 and 60 standard m 2 / h of hydrogen enter the hydrogenation reactor 31 for hydrogenation reaction to obtain the third material S3-1, which mainly includes the epoxy cyclododecane obtained by hydrogenation of the epoxy cyclododecadiene; the hydrogenation reactor is a fixed bed, the hydrogenation catalyst is a platinum supported catalyst with a loading of 1%, and the carrier is a mixture of alumina and zirconia in a mass ratio of 1:1. The hydrogenation reaction temperature is 100℃, the pressure in the tower is 0.1mpa, the space velocity is 1h -1 .

[0123] The second refining process: the third material S3-1 is input into the gas-liquid separation device 41, to obtain a gas phase S3-2 and a liquid phase S4-1, wherein the gas phase S3-2 is substantially unreacted hydrogen, which is returned to the hydrogen inlet of the hydrogenation reactor 31 for continuous reaction; the liquid phase S4-1 is input into the fourth rectifying column 42 for separation. The fourth rectifying column 42 has a top temperature of 91°C, a bottom temperature of 153°C, a top pressure of 0.05 bar, and a reflux ratio of 30. The top effluent of the fourth rectifying column 42 is mainly light component impurities, with a flow rate of 1.89 kg / h, wherein the cyclododecane is 56%, and the cycloepoxydodecane is 43.4%. The bottom effluent of the fourth rectifying column 42 is input into the fifth rectifying column 43 for rectification and separation, wherein the fifth rectifying column 43 has a top temperature of 140°C, a bottom temperature of 150°C, a top pressure of 0.05 bar, and a reflux ratio of 20. The top of the fifth rectifying column 43 obtains the cycloepoxydodecane product 155 kg / h, with a purity of 99.9% and a product yield of 96.4%. The bottom of the fifth rectifying column 43 obtains the second heavy component S4-4 at a flow rate of 0.98 kg / h, which mainly includes tar and about 43 wt% of cycloepoxydodecane. This part of the stream is returned to the third rectifying column 23 for further recovery.

[0124] Example 4

[0125] Based on the production process of the epoxycycloalkane shown in Example 2, this example shows a production process of an epoxycycloalkane under a specific working condition. It should be noted that this example only demonstrates an optimal working condition and does not limit the protection scope of the present application.

[0126] A production process of an epoxycycloalkane, taking a 10,000 tons / year epoxycyclooctane production device as an example, includes:

[0127] The oxidation process: the reactor is a series of 6 reaction kettles 11, the raw material is cyclooctadiene 2.2 t / h, and the solvent is pentanol 8.8 t / h, which are mixed and then added from the inlet of the first reaction kettle; 30 wt% hydrogen peroxide 1130 kg / h is divided into 5 equal parts and added into the first 5 reaction kettles; the reaction temperature is 110°C, the reaction pressure is 5000 pa, the single kettle material residence time is 2h, and the solid content of the titanium-silicon molecular sieve catalyst in each reactor is controlled at 20%. After the reaction is completed, the first material S1-4 flows out from the bottom of the 6th reaction kettle. The water content in the first material S1-4 is 8%, the solvent octanol is 72.4%, the cyclooctadiene is 9.2%, the epoxide primary product (including epoxycyclooctene, etc.) is 10.12%, and the others are 0.28%. The effective utilization rate of hydrogen peroxide in the reaction is 98.9%, and it is detected that the hydrogen peroxide in the material after the reaction is basically reacted (the hydrogen peroxide content is less than 0.05 wt%). The first material S1-4 flows out from the bottom of the 5th reaction kettle 11, is filtered through the membrane filtration device 5, and then enters the subsequent first refining process.

[0128] The first material S1-4 is separated in the first distillation column 21 at normal temperature, the top temperature of the first distillation column 21 is 59°C, the bottom temperature is 118°C, the top pressure is 0.9 bar, and the reflux ratio is 0.5. The crude solvent S2-1 is separated from the top of the first distillation column 21, and the organic solvent is separated in the solvent purification column 6, the top temperature is 90°C, the bottom temperature is 180°C, the top pressure is 0.5, and the reflux ratio is 0.5. The organic waste water 1565 kg / h is separated from the top of the solvent purification column 6 and sent out of the system, and the solvent pentanol 8201 kg / h is obtained by distillation at the bottom of the solvent purification column 6, wherein the concentration of pentanol is 99.95%, and the solvent is recycled to the reaction kettle 11 to continue to participate in the reaction. The bottom stream of the first distillation column 21 is separated in the second distillation column 22. The top temperature of the second distillation column 22 is 119°C, the bottom temperature is 158°C, the top pressure is 0.1 bar, and the reflux ratio is 2. The unreacted cyclooctadiene is separated from the top of the second distillation column 22, and the purity is 99.9%, which is returned to the reaction kettle 11 to continue to react. The bottom stream of the second distillation column 22 is separated in the third distillation column 23, the top temperature of the third distillation column 23 is 140°C, the bottom temperature is 200°C, the top pressure is 0.01 bar, and the reflux ratio is 5. The second material S2-5 mainly containing cyclooctene oxide is separated from the top of the third distillation column 23, and the flow rate is 1214 kg / h. The second material S2-5 is introduced into the hydrogenation process for hydrogenation reaction. The first heavy component S2-6 is obtained from the bottom of the third distillation column 23, which is a heavy component impurity, mainly tar, which is discharged out of the system.

[0129] The second material S2-5 and 450 standard m 2 / h of hydrogen are introduced into the hydrogenation reactor 31 for hydrogenation reaction to obtain the third material S3-1, which mainly includes cyclooctene oxide. The hydrogenation reactor is a fixed bed reactor, the hydrogenation catalyst is a palladium and ruthenium supported catalyst, the loading amount is 2%, and the carrier is a mixture of magnesium oxide and aluminum oxide in a mass ratio of 1:1. The hydrogenation reaction temperature is 80°C, the pressure is 0.05 mpa, the space velocity is 0.5 h -1 .

[0130] The second refining process: the third material S3-1 enters the gas-liquid separation device 41 to obtain a gas phase S3-2 and a liquid phase S4-1, wherein the gas phase S3-2 is substantially unreacted hydrogen, which is returned to the hydrogen inlet of the hydrogenation reactor 31 for continuous reaction; the liquid phase S4-1 enters the fourth distillation column 42 for separation, wherein the top temperature of the fourth distillation column 42 is 110°C, the bottom temperature is 177°C, the top pressure is 0.01 bar, and the reflux ratio is 20. The overhead of the fourth distillation column 42 mainly contains light component impurities, with a flow rate of 2.24 kg / h, including 53% of cyclooctane and 47% of cyclooctene oxide. The bottom product of the fourth distillation column 42 enters the fifth distillation column 43 for distillation separation, wherein the top temperature of the fourth distillation column 42 is 120°C, the bottom temperature is 160°C, the top pressure is 0.01 bar, and the reflux ratio is 5. The overhead of the fourth distillation column 42 obtains 1250 kg / h of cyclooctene oxide product, with a purity of 99.9%, and a product yield of 97.6%; the bottom product of the fourth distillation column 42 is the second heavy component S4-4 with a flow rate of 2.13 kg / h, mainly including about 46 wt% of cyclooctene oxide and about 54 wt% of tar, which is returned to the third distillation column 23 for further recovery of the product.

[0131] Example 5

[0132] Based on the production process of the epoxy cycloalkane shown in Example 2, this embodiment shows a production process of epoxy cyclohexadecane under a specific condition. It should be noted that this embodiment only demonstrates an optimal condition and does not limit the protection scope of the present application.

[0133] A production process of epoxy cyclohexadecane, taking a 500 tons / year epoxy cyclohexadecane production system as an example, including:

[0134] The oxidation process: the reactor is a 3-stage reaction kettle 11 in series, the raw material is cyclohexadecatriene 417 kg / h, the solvent is hexanol 840 kg / h, both of which are mixed and then added from the inlet of the first-stage reaction kettle; 25 wt% hydrogen peroxide 50 kg / h, divided into two equal parts and added into the first two-stage reaction kettle; the reaction temperature is 80°C, the pressure is 3000 pa, the single-pot material residence time is 3h, and the solid content of the titanium-silicon molecular sieve catalyst in each reactor is controlled at 20%. After the reaction is completed, the water content in the first material S1-4 is 2.87%, the solvent hexanol is 64.3%, the cyclohexadecatriene is 25.7%, the epoxy primary product (including epoxy cyclohexadecatriene and the like) is 6.48%, and the others are 0.65%. The effective utilization rate of hydrogen peroxide in the reaction is 99.1%, and it is detected that the hydrogen peroxide in the material after the reaction is substantially reacted. The first material S1-4 flows out from the bottom of the third-stage reaction kettle 11, is filtered by the membrane filtration device 5, and then enters the first refining process.

[0135] The first refined process: the first material S1-4 enters the first distillation column 21 at room temperature for separation, the overhead temperature of the first distillation column 21 is 80℃, the bottom temperature is 190℃, the overhead pressure is 1 bar, and the reflux ratio is 0.5; the crude solvent S2-1 is separated from the overhead, which enters the solvent purification column 6 for separation, the purpose is to separate the solvent and water, wherein the overhead temperature of the solvent purification column 6 is 60℃, the bottom temperature is 120℃, the overhead pressure is 1 bar, the reflux ratio is 30, the solvent purification column 6 separates the waste water 74.3kg / h from the overhead, and the solvent hexanol 834kg / h is distilled from the bottom, wherein the hexanol concentration is 99.95%, and is recycled back to the reaction kettle 11 to continue to participate in the reaction. The column bottom stream of the first distillation column 21 continues to enter the second distillation column 22 for separation, wherein the overhead temperature of the second distillation column 22 is 136℃, the bottom temperature is 187℃, the overhead pressure is 0.5bar, and the reflux ratio is 3; the second distillation column 22 separates the unreacted cyclohexadecatriene with a purity of 99.9% from the overhead, which returns to the reaction kettle 11 for continuous reaction, and the column bottom material of the second distillation column 22 enters the third distillation column 23 for distillation and separation; wherein the overhead temperature of the third distillation column 23 is 150℃, the bottom temperature is 205℃, the overhead pressure is 0.05bar, and the reflux ratio is 10; the second material S2-5 containing the primary product of epoxy is separated from the overhead, with a flow rate of 86kg / h, and enters the hydrogenation process for reaction; the first heavy component S2-6 containing heavy component impurities, mainly containing tar, is collected from the bottom of the third distillation column 23, which is excluded from the overhead.

[0136] Hydrogenation process: the second material S2-5 and 25 standard m 2 / h of hydrogen enters the hydrogenation reactor 31 for hydrogenation reaction to obtain the third material S3-1; the hydrogenation reactor 31 is a fixed bed reactor, the hydrogenation catalyst is a palladium supported catalyst with a loading of 1%, and the carrier is a mixture of alumina and zirconia in a mass ratio of 1:1. The hydrogenation reaction temperature is 80℃, the column pressure is 1mpa, the space velocity is 1h -1 .

[0137] The second refining process: the third material S3-1 enters the gas-liquid separation device 41, and the gaseous phase S3-2 product and the liquid phase S4-1 product are obtained, wherein the gaseous phase S3-2 is substantially unreacted hydrogen, which is returned to the inlet of the hydrogenation reactor 31 for continuous reaction, and the liquid phase S4-1 enters the fourth rectifying column 42 for separation; the top temperature of the fourth rectifying column 42 is 190℃, the bottom temperature is 175℃, the top pressure is 0.04bar, and the reflux ratio is 30; the top effluent is mainly light component impurities, and the flow rate is 1.89kg / h, wherein the cyclohexadecane is 56%, and the cyclohexadecene is 43.4%; the column bottom product of the fourth rectifying column 42 enters the fifth rectifying column 43 for rectification and separation; the top temperature of the fifth rectifying column 43 is 140℃, the bottom temperature is 150℃, the top pressure is 0.02bar, and the reflux ratio is 20; the top of the fifth rectifying column 43 obtains 85kg / h of the cyclohexadecene product with a purity of 99.9%, and the product yield is 98%; the column bottom of the fifth rectifying column 43 obtains 0.67kg / h of the second heavy component S4-4, and the cyclohexadecene accounts for 41% in the second heavy component, and the rest is tar; the second heavy component S4-4 is discharged from the column bottom of the fifth rectifying column 43 and is returned to the third rectifying column 23 for further recovery.

[0138] It can be proved by the above examples that the production process of the cyclohexadecene prepared by the present application has a purity of >99.8%, a product yield of >96%, and the hydrogen peroxide in the material is substantially reacted after the oxidation process (the content is less than 0.05wt%), and the effective utilization rate of hydrogen peroxide is >98%, which is a green and safe cyclohexadecene preparation process.

[0139] It should be noted that the above content is a further detailed description of the present application in combination with specific embodiments, and the specific implementation of the present application cannot be limited to these descriptions; the size data of the above embodiments does not limit the technical solutions, but only shows one specific working condition. For ordinary skilled persons in the technical field to which the present application belongs, some simple improvements and decorations can be made without departing from the concept of the present application, and all of them should be regarded as falling within the scope of protection of the present application.

Claims

1. A process for producing epoxy cycloalkanes, characterized in that, Includes the following processes Oxidation process: The oxidation process is carried out in N reactors connected in series, with the outlet of the previous reactor connected to the inlet of the next reactor; the raw material cyclic olefin and solvent are fed into the inlet of the first reactor, and the oxidant hydrogen peroxide is divided into N-1 portions and added to the first to the N-1th reactors respectively; the first material after oxidation reaction is output from the outlet of the last reactor, wherein N is at least 2; First refining step: The first material is separated from the solvent, unreacted cyclic olefins and the first heavy component by a first distillation operation to obtain the second material; Hydrogenation process: The second material undergoes a hydrogenation reaction under the action of a hydrogenation catalyst to obtain the third material; Second refining process: The third material is sequentially subjected to gas-liquid separation to remove unreacted hydrogen, and then separated into light components and second heavy components through a second distillation operation to obtain high-quality epoxy cycloalkane products; The unreacted cyclic olefins separated in the first refining step are returned to the oxidation step; the molar ratio of the cyclic olefins to the hydrogen peroxide in the hydrogen peroxide solution is (2-7):

1.

2. The production process of epoxy cycloalkane according to claim 1, characterized in that, The molar ratio of the cyclic olefin to the hydrogen peroxide in the hydrogen peroxide solution is (2-3):1; Preferably, the reaction temperature of the oxidation process is 80-110℃ and the pressure is 3000-6000Pa; in the oxidation process, the residence time of the reactants in each reactor is 1-3h.

3. The production process of epoxy cycloalkane according to claim 1, characterized in that, The concentration of the hydrogen peroxide is 25-70 wt%, preferably 30-50 wt%.

4. The production process of epoxycycloalkane according to claim 1, characterized in that, The cyclic olefin is a cyclic monoolefin or cyclic polyolefin with 8-16 carbon atoms; preferably, the cyclic olefin is a cyclic monoolefin or cyclic polyolefin with 12 carbon atoms. Preferably, the solvent is a C5-C8 alcohol; Preferably, the mass ratio of the cyclic olefin to the solvent is 1:(2-4).

5. The production process of epoxycycloalkane according to claim 1, characterized in that, N is a natural number between 2 and 8, preferably a natural number between 3 and 6.

6. The production process of epoxy cycloalkane according to claim 1, characterized in that, In the hydrogenation process, the molar ratio of the second material to hydrogen is 1:(2-4); Preferably, the reaction temperature of the hydrogenation process is 80-100℃, and the reaction pressure is 0.1-1MPa; Preferably, the feed space velocity of the second material in the hydrogenation process is 0.5-2 h⁻¹. -1 .

7. The production process of epoxy cycloalkane according to claim 1, characterized in that, The catalyst for the hydrogenation process is a supported catalyst comprising an active component and a support, wherein the active component comprises one or more of Pt, Pd, and Ru. Preferably, the carrier comprises one or more of alumina, silicon oxide, and magnesium oxide.

8. The production process of epoxycycloalkane according to claim 1, characterized in that, The crude solvent separated in the first refining step is purified by distillation and then returned to the oxidation step. Preferably, the temperature at the top of the solvent distillation purification column is 30-60℃, the temperature at the bottom of the column is 90-120℃, the pressure at the top of the column is 0.5-1 bar, and the reflux ratio is 20-30. Preferably, the hydrogen gas discharged during the gas-liquid separation in the second refining step is returned to the hydrogenation step; Preferably, the second heavy component separated in the second refining process is returned to the first refining process; Preferably, the first material is fed into the first refining process after being filtered.

9. The production process of epoxy cycloalkane according to claim 1, characterized in that, The first distillation operation includes primary distillation, secondary distillation, and tertiary distillation. Preferably, the top temperature of the primary distillation column is 50-90℃, the bottom temperature is 150-200℃, the top pressure is 0.5-1 bar, and the reflux ratio is 0.5-1. Preferably, the top temperature of the secondary distillation column is 100-140℃, the bottom temperature is 150-200℃, the top pressure is 0.1-0.5 bar, and the reflux ratio is 1-5. Preferably, the top temperature of the three-stage distillation column is 100-150℃, the bottom temperature is 160-210℃, the top pressure is 0.01-0.1 bar, and the reflux ratio is 5-20. Preferably, the second distillation operation includes four-stage distillation and five-stage distillation; Preferably, the top temperature of the four-stage distillation column is 90-120℃, the bottom temperature is 150-180℃, the top pressure is 0.01-0.1 bar, and the reflux ratio is 20-30. Preferably, the top temperature of the five-stage distillation column is 120-140℃, the bottom temperature is 150-180℃, the top pressure is 0.01-0.1 bar, and the reflux ratio is 5-20.

10. A production system for epoxy cycloalkane, characterized in that, Includes the following units Oxidation unit: includes N reactors connected in series, with the outlet of one reactor connected to the inlet of the next reactor. The first reactor is connected to the raw material cyclic olefin input pipe and the solvent input pipe. The first to N-1 reactors are connected to the hydrogen peroxide input pipe. The Nth reactor is provided with an outlet for the material after oxidation reaction. N is at least 2. First refining unit: includes at least one distillation column, and the outlet of the Nth reactor is connected to the inlet of the first distillation column of the first refining unit; Hydrogenation unit: includes a hydrogenation reactor, the top outlet of the last distillation column of the first refining unit is connected to the feed inlet of the hydrogenation reactor, and the hydrogenation reactor is also connected to a hydrogen input pipe; The second refining unit includes a gas-liquid separation device and at least one distillation column. The outlet of the hydrogenation reactor is connected to the inlet of the gas-liquid separation device, and the liquid phase outlet of the gas-liquid separation device is connected to the inlet of the first distillation column of the second refining unit. The top outlet of the last distillation column of the second refining unit outputs high-purity epoxy cycloalkane products.

11. The epoxy cycloalkane production system according to claim 10, characterized in that, N is a natural number from 2 to 8, preferably a natural number from 3 to 6; Preferably, a filtration device is installed on the pipeline connecting the Nth reactor and the first refining unit.

12. The epoxy cycloalkane production system according to claim 10, characterized in that, It also includes a solvent purification distillation column. When the first purification unit includes at least two distillation columns, the top outlet of the first distillation column is connected to the feed inlet of the solvent purification distillation column, and the bottom outlet of the solvent purification distillation column is connected to the feed inlet of the first reactor. Preferably, the system further includes a solvent purification distillation column. When the first purification unit includes at least three distillation columns, the top outlet of the first distillation column is connected to the feed inlet of the solvent purification distillation column, and the bottom outlet of the solvent purification distillation column is connected to the feed inlet of the first reactor. The top outlets of the distillation columns other than the first and last distillation columns are connected to the feed inlet of the first reactor. Preferably, the gas phase outlet of the gas-liquid separation device is connected to the hydrogen inlet of the hydrogenation reactor; Preferably, the bottom outlet of the last distillation column of the second refining unit is connected to the feed inlet of the third distillation column.

13. The epoxy cycloalkane production system according to claim 10, characterized in that, The first refining unit includes a first distillation column, a second distillation column, and a third distillation column connected in sequence. The outlet of the Nth reactor is connected to the inlet of the first distillation column, and the top outlet of the third distillation column is connected to the feed inlet of the hydrogenation reactor. Preferably, the second refining unit includes a fourth distillation column and a fifth distillation column connected in sequence.

Images