A process for the continuous production of dicumyl peroxide

Abstract

The application provides a method for continuously preparing dicumyl peroxide, and the method can well balance high conversion rate of raw materials and high selectivity of products, and is intrinsically safe in the reaction process. The method comprises the following steps: (1) passing cumene hydroperoxide solution with a concentration of 75-90 wt%, alpha,alpha-dimethylbenzyl alcohol and acid catalyst aqueous solution with a concentration of 50-80 wt% into a microchannel reactor to perform condensation reaction at 55-80 DEG C, and controlling the conversion rate of cumene hydroperoxide to be 60-85%; (2) sending the reaction mixture obtained in step (1) into a short-path molecular distiller to continuously perform condensation reaction at 35-50 DEG C, and performing vacuum dehydration in the condensation reaction process, so as to prepare the dicumyl peroxide.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of dicumyl peroxide preparation, in particular to a method for continuously preparing dicumyl peroxide. BACKGROUND

[0002] Dicumyl peroxide is a most commonly used symmetrical dialkyl organic peroxide, also known as vulcanizing agent DCP, white crystal, melting point 39℃-40℃, decomposition temperature 120℃-125℃, stable at room temperature, gradually turns yellow under light. The theoretical active oxygen content is 5.92%. Dicumyl peroxide can be used as a vulcanizing agent for natural rubber, synthetic rubber, such as a vulcanizing agent for ethylene propylene diene rubber (EPDM), nitrile rubber and silicone rubber, etc. Dicumyl peroxide can also be used as an initiator for polymerization reaction and as a crosslinking agent for polyethylene resin, such as commonly used as a crosslinking agent for polyethylene (PE), chlorinated polyethylene (CPE), polystyrene (PS). Dicumyl peroxide can also be used as an initiator for the synthesis of expandable polystyrene (EPS), a blowing agent for polyethylene vinyl acetate (EVA), etc. After DCP crosslinking, the physical properties of the polymer are greatly improved, and the heat resistance, chemical resistance, pressure resistance, crack resistance and mechanical strength are increased. DCP is widely used in the industries of wire and cable, shoemaking, building materials, etc. In recent years, with the continuous expansion of the market of high molecular materials, the demand for DCP is increasing year by year, and the market potential is huge.

[0003] At present, the production of dicumyl peroxide in industry all adopts batch kettle process. This process uses isopropylbenzene as raw material, oxidizes isopropylbenzene into hydrogen peroxide isopropylbenzene (CHP) through air oxidation, and generates α,α-dimethylbenzyl alcohol (DMBA) through reduction reaction with part of hydrogen peroxide isopropylbenzene. Then, dicumyl peroxide (DCP) is generated through condensation reaction of hydrogen peroxide isopropylbenzene and α,α-dimethylbenzyl alcohol under the action of an acid catalyst. After that, qualified products are obtained through processes such as alkali washing, water washing and crystallization. The condensation reaction process is as follows:

[0004] Main reaction:

[0005]

[0006] Side reaction:

[0007]

[0008] From the reaction process, the main reaction is a dehydration chemical equilibrium reaction process. In the condensation reaction process, the main side reactions include the dehydration of DMBA to generate alpha-methyl styrene (abbreviated as AMS), the acid-catalyzed decomposition of CHP to generate phenol and acetone, the acid-catalyzed decomposition of DCP to generate phenol, acetone and DMBA, and then the acid-catalyzed dehydration of DMBA to generate AMS. The side reactions of phenol and AMS occur to generate 4-cumyl phenol, and AMS itself polymerizes to generate dimers and trimers. The above decomposition reactions, alkylation reactions and polymerization reactions are all strong exothermic reactions, and once the reaction is out of control, it will cause an explosion.

[0009] Therefore, the condensation process has the following technical problems: (1) the main reaction is an acid-catalyzed reaction, but CHP and DCP are prone to secondary decomposition under the action of acid catalysis; (2) the main reaction is an equilibrium reaction, and the water generated in the system needs to be removed in time; (3) the reaction endpoint is difficult to control, the raw materials are not completely reacted, which affects the product quality, and excessive reaction leads to the secondary decomposition of DCP.

[0010] Patent US4266081A discloses a method for preparing dicumyl peroxide using a strong acid weak base salt (such as zinc chloride) as a catalyst. This patent has the problems of easy hydrolysis of the catalyst, strong corrosion and large amount of use.

[0011] Patent US4413148A discloses a method for preparing dicumyl peroxide. This patent uses a polar solvent such as triethyl phosphate, which is hardly distilled by water in the process of continuously removing water generated in the reaction, to achieve the purpose of inhibiting the decomposition of CHP and DCP. However, there is still a problem of low selectivity of DCP, especially when the CHP conversion rate reaches more than 90%, the selectivity of DCP is only about 90%.

[0012] Patents CN103145597B and CN104860861A disclose a production method of dicumyl peroxide, which relates to a method for reducing the production of by-products in the condensation reaction process of dicumyl peroxide. This patent uses a batch production process, and the selectivity of DCP is less than 94%, which still has the problem of low selectivity of DCP in the condensation reaction.

[0013] Patent CN102827051A relates to a synthesis method of dicumyl peroxide, and discloses a method for synthesizing dicumyl peroxide using pure benzyl alcohol and an oxidizing solution as raw materials. Although this patent has reduced the content of by-products such as phenol and acetone, the content of by-products such as phenol and acetone is still as high as 3.5-4.2%, which has the problems of low yield of DCP product and high content of by-products.

[0014] Patent CN113845457A discloses a method for preparing dicumyl peroxide by using SO4 2-A method for preparing cumene hydroperoxide by dehydrating and condensing dimethyl benzyl alcohol and cumene hydroperoxide in the presence of a ZnCl2-HY solid acid catalyst. The main disadvantages of this patent are that the solid acid catalyst has poor activity, requires a high reaction temperature, and the raw material cumene hydroperoxide and the product cumene hydroperoxide decompose severely, resulting in low effective utilization of the raw material and low yield of the product; on the other hand, with the increase in the number of uses, the active components of the catalyst are lost, resulting in a decrease in the acid sites of the catalyst and a decrease in the catalytic performance of the catalyst, greatly reducing the service life of the catalyst.

[0015] Patent CN109384699A discloses an online full-continuous flow production process for directly preparing organic peroxide from hydrogen peroxide. This patent has the problems of large catalyst dosage, long residence time, and severe decomposition of organic peroxide, resulting in low product selectivity.

[0016] Patent CN117680069A discloses a reaction method and device for cumene hydroperoxide. The reaction liquid circulates between the reaction liquid tank and the thin film reactor, and the water produced during the reaction is removed by the vacuum system connected to the reaction liquid tank and the thin film reactor. In this patent, the reaction liquid needs to be circulated in the thin film reactor and the negative pressure environment for multiple times, and there are problems of long reaction time and uneven mixing of oil and water, resulting in local material decomposition.

[0017] In summary, the condensation process for industrial production of cumene hydroperoxide currently has the problems of large catalyst dosage, long reaction time, poor product selectivity, poor process controllability, low safety factor, and / or low production efficiency. SUMMARY

[0018] In view of the deficiencies of the prior art, the present application provides a method for continuously preparing cumene hydroperoxide. The method of the present application can well balance high conversion rate of raw materials and high selectivity of products, and the reaction process is intrinsically safe.

[0019] To achieve the purpose of the present application, the following technical solutions are provided:

[0020] The present application provides a method for continuously preparing cumene hydroperoxide, comprising the following steps:

[0021] (1) passing a 75-90wt% concentration of cumene hydroperoxide solution, α,α-dimethyl benzyl alcohol, and a 50-80wt% concentration of acidic catalyst aqueous solution into a microchannel reactor to perform condensation reaction at 55-80℃, and controlling the conversion rate of cumene hydroperoxide to be 60-85%;

[0022] (2) the reaction mixture obtained in step (1) is fed into a short path molecular distiller to continue the condensation reaction at 35-50°C, and vacuum dehydration is performed during the condensation reaction to obtain said dicumyl peroxide.

[0023] Preferably, in (1), the concentration of the aqueous solution of the acidic catalyst is 55-75 wt%, preferably 60-70 wt%.

[0024] Preferably, in step (1), the amount of the acidic catalyst used is 200-2000 ppm, preferably 600-1600 ppm, more preferably 1000-1200 ppm.

[0025] Preferably, in step (1), the concentration of the cumene hydroperoxide solution is 78-88 wt%, more preferably 80-85 wt%.

[0026] Preferably, the reaction temperature of step (1) is 60-75°C, preferably 65-70°C;

[0027] and / or, the reaction temperature of step (2) is 38-48°C, preferably 42-45°C.

[0028] In some embodiments, in step (1), the reaction time of the condensation reaction is 40-120 s, preferably 60-100 s, more preferably 70-80 s;

[0029] In step (2), the reaction time of the condensation reaction is 20-80 s, preferably 40-60 s, more preferably 45-55 s.

[0030] In some embodiments, in step (2), the vacuum degree of the short path molecular distiller is 1-10 KPa, preferably 3-8 KPa, more preferably 5-7 KPa;

[0031] and / or, in step (2), the rotation speed of the short path molecular distiller is 50-500 rpm, preferably 100-400 rpm, more preferably 200-300 rpm;

[0032] and / or, in step (2), the feeding speed of the reaction mixture is 1-10 ml / min, preferably 2-8 ml / min, more preferably 4-6 ml / min.

[0033] Preferably, in step (1), the conversion rate of the cumene hydroperoxide is controlled to be 65-80%, preferably 70-75%.

[0034] In some embodiments, in step (1), the molar ratio of the cumene hydroperoxide to the α,α-dimethylbenzyl alcohol is (0.8-1.5):1, preferably (0.9-1.2):1, more preferably (1.0-1.1):1.

[0035] In some embodiments, the solvent in the cumene hydroperoxide solution is cumene.

[0036] In some embodiments, in step (1), the acidic catalyst is selected from one or more of sulfuric acid, hydrochloric acid, phosphoric acid, perchloric acid, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, and trichloroacetic acid; preferably one or more of sulfuric acid, perchloric acid, p-toluenesulfonic acid, and dodecylbenzenesulfonic acid; more preferably one or both of dodecylbenzenesulfonic acid and p-toluenesulfonic acid.

[0037] The technical solution provided by the present application has the following beneficial effects:

[0038] The method of the present application for continuously preparing dicumyl peroxide comprises the following steps: first, in a micro-channel reactor, under non-dehydration conditions, a first-stage condensation reaction is carried out on a relatively high concentration of cumene hydroperoxide solution and α,α-dimethylbenzyl alcohol in the presence of a relatively high concentration of acidic catalyst at a relatively high reaction temperature (55-80℃), and the conversion rate of the cumene hydroperoxide is controlled to be 60-85%; on this basis, the reaction mixture obtained from the first-stage condensation reaction is fed into a short-path molecular distiller to carry out a second-stage condensation reaction under vacuum dehydration conditions at a relatively low reaction temperature (35-50℃); the above-mentioned first and second condensation reaction stages are combined to prepare dicumyl peroxide, and finally a good balance of high conversion rate, high utilization rate and high selectivity of the product is achieved, and the reaction process is intrinsically safe. DETAILED DESCRIPTION

[0039] In order to facilitate the understanding of the present application, the present application will be further described below in conjunction with examples. It should be understood that the following examples are only for better understanding of the present application, and do not mean that the present application is limited to the following examples only.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0041] The present application provides a method for continuously preparing dicumyl peroxide, comprising the following steps:

[0042] (1) passing a cumene hydroperoxide solution with a concentration of 75-90 wt% (e.g. 75 wt%, 80 wt%, 85 wt%, 90 wt%, etc.), an α,α-dimethylbenzyl alcohol, and an acidic catalyst aqueous solution with a concentration of 50-80 wt% (e.g. 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, 85 wt%, 90 wt%, etc.) into a micro-channel reactor to conduct a condensation reaction at 55-80°C (e.g. 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, etc.) and controlling the conversion rate of the cumene hydroperoxide to be 60-85% (e.g. 60%, 65%, 70%, 75%, 80%, 85%, etc.);

[0043] (2) passing the reaction mixture obtained in step (1) into a short path molecular still to continue the condensation reaction at 35-50°C (e.g. 35°C, 40°C, 45°C, 50°C, etc.) and conducting vacuum dehydration during the condensation reaction to obtain the cumene hydroperoxide.

[0044] In the method of the present application, the cumene hydroperoxide solution with a higher concentration and the α,α-dimethylbenzyl alcohol are first subjected to a first stage condensation reaction in the presence of the acidic catalyst with a higher concentration at a relatively high reaction temperature (55-80°C) in the micro-channel reactor without dehydration, and the conversion rate of the cumene hydroperoxide is controlled to be 60-85%, which can reduce the decomposition of the cumene hydroperoxide while ensuring the high selectivity of the cumene hydroperoxide; on this basis, the reaction mixture obtained in the first stage condensation reaction is passed into a short path molecular still to conduct a second stage condensation reaction under the condition of vacuum dehydration at a relatively low reaction temperature (35-50°C), which can realize the rapid conversion of the cumene hydroperoxide in the later stage of the reaction and the low decomposition rate of the product; the above first and second stage condensation reactions are combined to prepare the cumene hydroperoxide, which can ultimately realize the good balance of the high conversion rate, high utilization rate of the raw materials, and high selectivity of the product, and the reaction process is intrinsically safe. The conversion rate of the cumene hydroperoxide can reach more than 99.0% and the selectivity of the cumene hydroperoxide can reach more than 95% by the method of the present application.

[0045] In the preferred embodiments, the concentration of the acidic catalyst aqueous solution in step (1) is 55-75 wt%, preferably 60-70 wt%.

[0046] In the preferred embodiments, the amount of the acidic catalyst used in step (1) is 200-2000 ppm, preferably 600-1600 ppm, and more preferably 1000-1200 ppm, based on the total mass of the cumene hydroperoxide.

[0047] In preferred embodiments, the concentration of the cumene hydroperoxide solution in step (1) is 78-88wt%, more preferably 80-85wt%.

[0048] In preferred embodiments, the reaction temperature in step (1) is 60-75°C, preferably 65-70°C; and / or, the reaction temperature in step (2) is 38-48°C, preferably 42-45°C.

[0049] In some embodiments, the reaction time of the condensation reaction in step (1) is 40-120s, preferably 60-100s, more preferably 70-80s.

[0050] In step (2), the reaction time of the condensation reaction is 20-80s, preferably 40-60s, more preferably 45-55s.

[0051] In some embodiments, the vacuum degree of the short path molecular distiller in step (2) is 1-10KPa, such as 1KPa, 3KPa, 5KPa, 7KPa, 8KPa, 10KPa, etc., preferably 3-8KPa, more preferably 5-7KPa. During the reaction in step (2) under vacuum, water in the system is continuously removed as the reaction proceeds.

[0052] In some embodiments, the rotation speed of the short path molecular distiller in step (2) is 50-500rpm, preferably 100-400rpm, more preferably 200-300rpm.

[0053] In some embodiments, the feeding speed of the reaction mixture in step (2) is 1-10ml / min, preferably 2-8ml / min, more preferably 4-6ml / min.

[0054] In the method of the present application, the conversion rate of cumene hydroperoxide in step (1) is controlled to be 60-85%, preferably 65-80%, more preferably 70-75%. In some examples, the conversion rate can be the equilibrium conversion rate of step (1).

[0055] In some embodiments, the molar ratio of the cumene hydroperoxide to the a,a-dimethylbenzyl alcohol in step (1) is (0.8-1.5):1, preferably (0.9-1.2):1, more preferably (1.0-1.1):1.

[0056] In some embodiments, the solvent in the cumene hydroperoxide solution is cumene.

[0057] In some embodiments, in step (1), the acidic catalyst is selected from one or more of sulfuric acid, hydrochloric acid, phosphoric acid, perchloric acid, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, and trichloroacetic acid; preferably one or more of sulfuric acid, perchloric acid, p-toluenesulfonic acid, and dodecylbenzenesulfonic acid; more preferably one or both of dodecylbenzenesulfonic acid and p-toluenesulfonic acid. With the preferred catalyst, under other conditions being substantially the same, the conversion rate of cumene hydroperoxide and the selectivity of the product can be further improved.

[0058] The main reaction of the present application is a chemical equilibrium reaction process. As the condensation reaction proceeds, the amount of water produced gradually accumulates, the concentration of the acid catalyst in the reaction system gradually decreases to reach the reaction equilibrium, which leads to a slower reaction rate. Therefore, during the condensation reaction process, the water produced by the reaction needs to be removed from the reaction system in a timely manner to ensure sufficient acid concentration to achieve the purpose of improving reaction efficiency. At the same time, during the entire dehydration process, due to the fluctuation of the vacuum degree of the system, the local catalyst concentration is too high, which leads to the decomposition of the raw material cumene hydroperoxide and the product, thereby reducing the utilization rate of the raw material and the selectivity of the product. Therefore, during the condensation reaction process, attention should not only be paid to the reaction efficiency, but also to the conversion rate, utilization rate of cumene hydroperoxide, and selectivity of the product, to improve the utilization rate of the raw material and reduce material consumption. The present application uses a combination of a micro-channel reactor and a short-path molecular still to continuously produce dicumyl peroxide. The first-stage condensation reaction is carried out in the micro-channel reactor at 55-80°C, which controls the conversion rate of cumene hydroperoxide in the range of 60-85%. Then, the second-stage condensation reaction is carried out in the short-path molecular still at 35-50°C and under vacuum dehydration conditions. The temperature of the first-stage condensation reaction is higher than that of the second-stage condensation reaction. The preparation method of the present application can reduce the decomposition of cumene hydroperoxide in the first stage, and at the same time, it can also ensure the rapid conversion of cumene hydroperoxide and the low decomposition rate of the product in the later stage of the second-stage reaction, ultimately achieving high conversion rate, high utilization rate of raw materials, high selectivity of products, and intrinsic safety of the reaction process. Using the method of the present application to continuously produce dicumyl peroxide, the conversion rate of cumene hydroperoxide can reach more than 99.0%, and the selectivity of dicumyl peroxide can reach more than 95%.

[0059] The conditions for preparing DCP by CHP and DMBA condensation reaction are harsh. In order to ensure high conversion rate and high utilization rate of CHP, high selectivity of DCP and the intrinsic safety of the reaction, the first step of the present application adopts a micro-channel reactor, and the reaction is completed under high temperature, high catalyst mass concentration and non-dehydration conditions, so that the conversion rate of CHP is controlled in the range of 60-85%. Due to the increase of water in the system, the decomposition of CHP is inhibited, and at the same time the high selectivity of DCP is ensured. The conversion rate of CHP in the range of 60-85% can ensure that the selectivity of DCP is maintained above 95%. The present inventors have found that if the conversion rate of CHP is less than 60%, CHP cannot be completely converted in the second step reaction; if the conversion rate of CHP is greater than 85%, DCP decomposes to cause the selectivity to rapidly decrease.

[0060] Under the premise of high conversion rate of CHP, in order to further ensure high utilization rate of CHP and high selectivity of DCP, the second step reaction of the present application adopts a short-path molecular distiller, and the reaction is completed under low temperature and vacuum dehydration conditions, which realizes the rapid conversion of CHP, low decomposition rate of CHP and DCP, thereby avoiding the occurrence of side reactions such as decomposition, alkylation and polymerization, and further reducing the risk of reaction runaway.

[0061] Compared with the batch process, the combined process based on the micro-channel reactor and the short-path molecular distiller of the present application has the advantages of simple operation, high automation degree, easy control of reaction process, low energy consumption, few side reactions, stable product quality and high production efficiency.

[0062] The present application will be further illustrated by specific examples, but should not be understood as being limited to the present application.

[0063] If the specific experimental steps or conditions are not specified in the examples, the corresponding conventional experimental steps can be operated or the conditions can be used. If the reagents or instruments are not specified by the manufacturer, they are conventional products that can be obtained by market purchase.

[0064] The reaction conversion rate and selectivity are analyzed and determined by using liquid chromatography external standard standard curve method.

[0065] The chromatographic analysis conditions are as follows: Shimadzu liquid chromatograph SPD-20A; column oven: CT0-10ASvp; column temperature: 35℃, chromatographic column is T3 column, mobile phase is water and acetonitrile, water / acetonitrile = 25:75 (vol / vol), total flow rate is 1 ml / min, residence time is 40 min, detector wavelength is 254 nm.

[0066] Example 1

[0067] (1) At room temperature, 60wt% aqueous dodecylbenzenesulfonic acid and 99.9% pure a,a-dimethylbenzyl alcohol were mixed uniformly, and then the mixed materials and 80wt% cumene hydroperoxide solution (solvent is cumene) were simultaneously pumped into the micro-channel reactor by the help of a laminar pump, and reacted at 65°C for 80s. Through liquid chromatography analysis, the conversion rate of cumene hydroperoxide was 75%, and the selectivity of dicumyl peroxide was 97.8%. Among them, the molar ratio of cumene hydroperoxide to a,a-dimethylbenzyl alcohol was 1:1; based on the total mass of cumene hydroperoxide, the amount of dodecylbenzenesulfonic acid was 1000ppm.

[0068] (2) The reaction mother liquor obtained in step (1) was pumped into a short path molecular still at a feed rate of 6ml / min by a laminar pump, and the short path molecular still was rotated at 200rpm, and reacted at a reaction temperature of 42°C and a vacuum degree of 5KPa for 55s. Through liquid chromatography analysis, the conversion rate of cumene hydroperoxide was 100%, and the selectivity of dicumyl peroxide was 97%.

[0069] Example 2

[0070] (1) At room temperature, 70wt% aqueous p-toluenesulfonic acid and 99.9% pure a,a-dimethylbenzyl alcohol were mixed uniformly, and then the mixed materials and 85wt% cumene hydroperoxide solution (solvent is cumene) were simultaneously pumped into the micro-channel reactor by the help of a laminar pump, and reacted at 70°C for 70s. Through liquid chromatography analysis, the conversion rate of cumene hydroperoxide was 70%, and the selectivity of dicumyl peroxide was 97.3%. Among them, the molar ratio of cumene hydroperoxide to a,a-dimethylbenzyl alcohol was 0.9:1; based on the total mass of cumene hydroperoxide, the amount of p-toluenesulfonic acid was 1200ppm.

[0071] (2) The reaction mother liquor obtained in step (1) was pumped into a short path molecular still at a feed rate of 4ml / min by a laminar pump, and the short path molecular still was rotated at 300rpm, and reacted at a reaction temperature of 45°C and a vacuum degree of 8KPa for 45s. Through liquid chromatography analysis, the conversion rate of cumene hydroperoxide was 99.8%, and the selectivity of dicumyl peroxide was 96.2%.

[0072] Example 3

[0073] (1) At room temperature, 55wt% p-toluenesulfonic acid aqueous solution and α,α-dimethylbenzyl alcohol with purity of 99.9% were mixed uniformly, and then the mixed materials and 88wt% cumene hydroperoxide solution (solvent is cumene) were simultaneously pumped into the micro-channel reactor by the help of the laminar pump, and reacted for 100s at the reaction temperature of 60℃. Through liquid chromatography analysis, the conversion rate of cumene hydroperoxide was 80%, and the selectivity of dicumyl peroxide was 97.4%. Among them, the molar ratio of cumene hydroperoxide to α,α-dimethylbenzyl alcohol was 1.5:1; and the amount of p-toluenesulfonic acid was 1600ppm based on the total mass of cumene hydroperoxide.

[0074] (2) The reaction mother liquor obtained in step (1) was pumped into the short-path molecular still at a feeding speed of 8ml / min by the help of the laminar pump, and the short-path molecular still was rotated at a speed of 400rpm, and reacted for 40s at the reaction temperature of 48℃ and the vacuum degree of 7KPa. Through liquid chromatography analysis, the conversion rate of cumene hydroperoxide was 99.6%, and the selectivity of dicumyl peroxide was 96.4%.

[0075] Example 4

[0076] (1) At room temperature, 75wt% sulfuric acid aqueous solution and α,α-dimethylbenzyl alcohol with purity of 99.9% were mixed uniformly, and then the mixed materials and 78wt% cumene hydroperoxide solution (solvent is cumene) were simultaneously pumped into the micro-channel reactor by the help of the laminar pump, and reacted for 60s at the reaction temperature of 75℃. Through liquid chromatography analysis, the conversion rate of cumene hydroperoxide was 65%, and the selectivity of dicumyl peroxide was 96.8%. Among them, the molar ratio of cumene hydroperoxide to α,α-dimethylbenzyl alcohol was 1.1:1; and the amount of sulfuric acid was 600ppm based on the total mass of cumene hydroperoxide.

[0077] (2) The reaction mother liquor obtained in step (1) was pumped into the short-path molecular still at a feeding speed of 2ml / min by the help of the laminar pump, and the short-path molecular still was rotated at a speed of 100rpm, and reacted for 60s at the reaction temperature of 38℃ and the vacuum degree of 3KPa. Through liquid chromatography analysis, the conversion rate of cumene hydroperoxide was 99.0%, and the selectivity of dicumyl peroxide was 95.2%.

[0078] Example 5

[0079] (1) At room temperature, 50wt% aqueous dodecylbenzenesulfonic acid and 99.9% purity α,α-dimethylbenzyl alcohol were mixed uniformly, and then the mixed materials and 90wt% cumene hydroperoxide solution (solvent is cumene) were simultaneously pumped into the micro-channel reactor by the help of the laminar pump, and reacted at 55℃ for 120s. Through liquid chromatography analysis, the conversion rate of cumene hydroperoxide was 60%, and the selectivity of dicumyl peroxide was 96.9%. Among them, the molar ratio of cumene hydroperoxide to α,α-dimethylbenzyl alcohol was 1.2:1; based on the total mass of cumene hydroperoxide, the amount of dodecylbenzenesulfonic acid was 2000ppm.

[0080] (2) The reaction mother liquor obtained in step (1) was pumped into a short path molecular still at a feeding speed of 1ml / min by the help of the laminar pump, and the short path molecular still was rotated at 50rpm, and reacted at 50℃ and vacuum degree of 10KPa for 80s. Through liquid chromatography analysis, the conversion rate of cumene hydroperoxide was 99.2%, and the selectivity of dicumyl peroxide was 96.6%.

[0081] Example 6

[0082] (1) At room temperature, 80wt% aqueous p-toluenesulfonic acid and 99.9% purity α,α-dimethylbenzyl alcohol were mixed uniformly, and then the mixed materials and 75wt% cumene hydroperoxide solution (solvent is cumene) were simultaneously pumped into the micro-channel reactor by the help of the laminar pump, and reacted at 80℃ for 40s. Through liquid chromatography analysis, the conversion rate of cumene hydroperoxide was 85%, and the selectivity of dicumyl peroxide was 97.1%. Among them, the molar ratio of cumene hydroperoxide to α,α-dimethylbenzyl alcohol was 0.8:1; based on the total mass of cumene hydroperoxide, the amount of p-toluenesulfonic acid was 200ppm.

[0083] (2) The reaction mother liquor obtained in step (1) was pumped into a short path molecular still at a feeding speed of 10ml / min by the help of the laminar pump, and the short path molecular still was rotated at 500rpm, and reacted at 35℃ and vacuum degree of 1KPa for 20s. Through liquid chromatography analysis, the conversion rate of cumene hydroperoxide was 100%, and the selectivity of dicumyl peroxide was 96.5%.

[0084] Example 7 (compared with Example 6)

[0085] (1) At room temperature, 80wt% perchloric acid aqueous solution and α,α-dimethylbenzyl alcohol with purity of 99.9% were mixed uniformly, then the mixed materials and 75wt% cumene hydroperoxide solution (solvent is cumene) were simultaneously pumped into the micro-channel reactor by the help of the laminar flow pump, the reaction was carried out at 80℃ for 40s, through liquid chromatography analysis, the conversion rate of cumene hydroperoxide was 80%, and the selectivity of dicumyl peroxide was 95.4%. Among them, the molar ratio of cumene hydroperoxide to α,α-dimethylbenzyl alcohol was 0.8:1; based on the total mass of cumene hydroperoxide, the amount of p-toluenesulfonic acid was 200ppm.

[0086] (2) The reaction mother liquor obtained in step (1) was pumped into the short path molecular still at a feeding speed of 10ml / min by the help of the laminar flow pump, the rotation speed of the short path molecular still was 500rpm, the reaction was carried out at 35℃ and the vacuum degree was 1KPa for 20s, through liquid chromatography analysis, the conversion rate of cumene hydroperoxide was 100%, and the selectivity of dicumyl peroxide was 95%.

[0087] Comparative Example 1 (compared with Example 1)

[0088] (1) At room temperature, 60wt% dodecylbenzenesulfonic acid aqueous solution and α,α-dimethylbenzyl alcohol with purity of 99.9% were mixed uniformly, then the mixed materials and 80wt% cumene hydroperoxide solution (solvent is cumene) were simultaneously pumped into the micro-channel reactor by the help of the laminar flow pump, the reaction was carried out at 65℃ for 50s, through liquid chromatography analysis, the conversion rate of cumene hydroperoxide was 55%, and the selectivity of dicumyl peroxide was 98.2%. Among them, the molar ratio of cumene hydroperoxide to α,α-dimethylbenzyl alcohol was 1:1; based on the total mass of cumene hydroperoxide, the amount of dodecylbenzenesulfonic acid was 1000ppm.

[0089] (2) The reaction mother liquor obtained in step (1) was pumped into the short path molecular still at a feeding speed of 6ml / min by the help of the laminar flow pump, the rotation speed of the short path molecular still was 200rpm, the reaction was carried out at 42℃ and the vacuum degree was 5KPa for 55s, through liquid chromatography analysis, the conversion rate of cumene hydroperoxide was 95.6%, and the selectivity of dicumyl peroxide was 95.3%.

[0090] Comparative Example 2 (compared with Example 1)

[0091] (1) At room temperature, 60wt% aqueous dodecylbenzenesulfonic acid solution and α,α-dimethylbenzyl alcohol with a purity of 99.9% were mixed uniformly, and then the mixed materials and 80wt% cumene hydroperoxide solution (solvent is cumene) were simultaneously pumped into the micro-channel reactor by the help of a laminar pump, and reacted at a reaction temperature of 65°C for 120s. Through liquid chromatography analysis, the conversion rate of cumene hydroperoxide was 90%, and the selectivity of dicumyl peroxide was 95.1%. Among them, the molar ratio of cumene hydroperoxide to α,α-dimethylbenzyl alcohol was 1:1; and the amount of dodecylbenzenesulfonic acid was 1000ppm based on the total mass of cumene hydroperoxide.

[0092] (2) The reaction mother liquor obtained in step (1) was pumped into a short-path molecular still at a feeding speed of 6ml / min by the help of a laminar pump, and the short-path molecular still was rotated at a speed of 200rpm, and reacted at a reaction temperature of 42°C and a vacuum degree of 5KPa for 55s. Through liquid chromatography analysis, the conversion rate of cumene hydroperoxide was 100%, and the selectivity of dicumyl peroxide was 93.2%.

[0093] Comparative Example 3 (compared with Example 1)

[0094] (1) At room temperature, 60wt% aqueous dodecylbenzenesulfonic acid solution and α,α-dimethylbenzyl alcohol with a purity of 99.9% were mixed uniformly, and then the mixed materials and 80wt% cumene hydroperoxide solution (solvent is cumene) were simultaneously pumped into the micro-channel reactor by the help of a laminar pump, and reacted at a reaction temperature of 42°C for 80s. Through liquid chromatography analysis, the conversion rate of cumene hydroperoxide was 40%, and the selectivity of dicumyl peroxide was 96.4%. Among them, the molar ratio of cumene hydroperoxide to α,α-dimethylbenzyl alcohol was 1:1; and the amount of dodecylbenzenesulfonic acid was 1000ppm based on the total mass of cumene hydroperoxide.

[0095] (2) The reaction mother liquor obtained in step (1) was pumped into a short-path molecular still at a feeding speed of 6ml / min by the help of a laminar pump, and the short-path molecular still was rotated at a speed of 200rpm, and reacted at a reaction temperature of 65°C and a vacuum degree of 5KPa for 55s. Through liquid chromatography analysis, the conversion rate of cumene hydroperoxide was 100%, and the selectivity of dicumyl peroxide was 85.6%.

[0096] Comparative Example 4

[0097] (1) At room temperature, 60wt% dodecylbenzenesulfonic acid aqueous solution and α,α-dimethylbenzyl alcohol with purity of 99.9% were mixed uniformly, then the mixed materials and 70wt% cumene hydroperoxide solution (solvent is cumene) were simultaneously pumped into the micro-channel reactor by the help of the laminar pump, and the reaction was carried out at 65℃ for 100s. Through liquid chromatography analysis, the conversion rate of cumene hydroperoxide was 73.5%, and the selectivity of dicumyl peroxide was 96.5%. In the reaction, the molar ratio of cumene hydroperoxide to α,α-dimethylbenzyl alcohol was 1:1; and the amount of dodecylbenzenesulfonic acid was 1000ppm based on the total mass of cumene hydroperoxide.

[0098] (2) The reaction mother liquor obtained in step (1) was pumped into the short path molecular still by the help of the laminar pump at a feeding speed of 6ml / min, and the rotation speed of the short path molecular still was 200rpm. The reaction was carried out at 42℃ and the vacuum degree was 5KPa for 55s. Through liquid chromatography analysis, the conversion rate of cumene hydroperoxide was 96.7%, and the selectivity of dicumyl peroxide was 94.3%.

[0099] Comparative Example 5 (compared with Example 1)

[0100] (1) At room temperature, 60wt% dodecylbenzenesulfonic acid aqueous solution and α,α-dimethylbenzyl alcohol with purity of 99.9% were mixed uniformly, then the mixed materials and 70wt% cumene hydroperoxide solution (solvent is cumene) were simultaneously pumped into the micro-channel reactor by the help of the laminar pump, and the reaction was carried out at 65℃ for 100s. Through liquid chromatography analysis, the conversion rate of cumene hydroperoxide was 73.5%, and the selectivity of dicumyl peroxide was 96.5%. In the reaction, the molar ratio of cumene hydroperoxide to α,α-dimethylbenzyl alcohol was 1:1; and the amount of dodecylbenzenesulfonic acid was 1000ppm based on the total mass of cumene hydroperoxide.

[0101] (2) The reaction mother liquor obtained in step (1) was pumped into the short path molecular still by the help of the laminar pump at a feeding speed of 6ml / min, and the rotation speed of the short path molecular still was 200rpm. The reaction was carried out at 42℃ and the vacuum degree was 5KPa for 55s. Through liquid chromatography analysis, the conversion rate of cumene hydroperoxide was 96.7%, and the selectivity of dicumyl peroxide was 94.3%.

[0102] The experimental results of the above examples and comparative examples are summarized in Table 1 as follows.

[0103] Table 1 Summary of experimental results of examples and comparative examples

[0104]

[0105]

[0106] From the above experimental results, it can be seen that in the process of continuously preparing dicumyl peroxide, the embodiment adopting the method of the present application can give consideration to both the high conversion rate (more than 99%) of cumene hydroperoxide and the selectivity (more than 95%) of dicumyl peroxide.

[0107] It is easily understood that the above embodiments are only examples for clearly illustrating the present application, and are not intended to limit the present application. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, it is not necessary and also impossible to enumerate all the embodiments. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A process for the continuous production of dicumyl peroxide, characterized in that, The method comprises the following steps: (1) passing a cumene hydroperoxide solution with a concentration of 75-90wt%, α,α-dimethylbenzyl alcohol and an acidic catalyst aqueous solution with a concentration of 50-80wt% into a micro-channel reactor to carry out a condensation reaction at 55-80℃, and controlling the conversion rate of the cumene hydroperoxide to be 60-85%; (2) sending the reaction mixture obtained in step (1) into a short path molecular distiller to continue the condensation reaction at 35-50℃, and carrying out vacuum dehydration during the condensation reaction to obtain the said dicumyl peroxide.

2. The method of claim 1, wherein, In step (1), the concentration of the acidic catalyst aqueous solution is 55-75wt%.

3. The method of claim 2, wherein, In step (1), the concentration of the acidic catalyst aqueous solution is 60-70wt%.

4. The method according to any one of claims 1 to 3, characterized in that, The amount of the acidic catalyst in step (1) is 200-2000ppm based on the total mass of the cumene hydroperoxide.

5. The method of claim 4, wherein, The amount of the acidic catalyst in step (1) is 600-1600ppm based on the total mass of the cumene hydroperoxide.

6. The method of claim 5, wherein, The amount of the acidic catalyst in step (1) is 1000-1200ppm based on the total mass of the cumene hydroperoxide.

7. The method according to any one of claims 1 to 3, characterized in that, In step (1), the concentration of the cumene hydroperoxide solution is 78-88wt%.

8. The method of claim 7, wherein, In step (1), the concentration of the cumene hydroperoxide solution is 80-85wt%.

9. The method according to any one of claims 1 to 3, characterized in that, The reaction temperature of step (1) is 60-75℃; And / or, the reaction temperature of step (2) is 38-48℃.

10. The method of claim 9, wherein, The reaction temperature of step (1) is 65-70℃; And / or, the reaction temperature of step (2) is 42-45℃.

11. The method according to any one of claims 1 to 3, characterized in that, In step (1), the reaction time of the condensation reaction is 40-120s; In step (2), the reaction time of the condensation reaction is 20-80s.

12. The method of claim 11, wherein, In step (1), the reaction time of the condensation reaction is 60-100s; In step (2), the reaction time of the condensation reaction is 40-60s.

13. The method of claim 11, wherein, In step (1), the reaction time of the condensation reaction is 70-80s; In step (2), the reaction time of the condensation reaction is 45-55s.

14. The method according to any one of claims 1 to 3, characterized in that, In step (2), the vacuum degree of the short path molecular distiller is 1-10KPa; And / or, in step (2), the rotation speed of the short path molecular distiller is 50-500rpm; And / or, in step (2), the feeding speed of the reaction mixture is 1-10ml / min.

15. The method of claim 14, wherein, In step (2), the vacuum degree of the short path molecular distiller is 3-8KPa; And / or, in step (2), the rotation speed of the short path molecular distiller is 100-400rpm; And / or, in step (2), the feeding speed of the reaction mixture is 2-8ml / min.

16. The method of claim 14, wherein, In step (2), the vacuum degree of the short path molecular distiller is 5-7KPa; And / or, in step (2), the rotation speed of the short path molecular distiller is 200-300rpm; And / or, in step (2), the feeding speed of the reaction mixture is 4-6ml / min.

17. The method of any one of claims 1-3, wherein, In step (1), the conversion rate of the cumene hydroperoxide is controlled to be 65-80%.

18. The method of claim 17, wherein, In step (1), the conversion of the cumene hydroperoxide is controlled to be 70-75%.

19. The method of any one of claims 1-3, wherein, In step (1), the molar ratio of the cumene hydroperoxide to the a,a-dimethylbenzyl alcohol is (0.8-1.5):

1. In step (1), the molar ratio of the cumene hydroperoxide to the a,a-dimethylbenzyl alcohol is (0.9-1.2):

1.

20. The method of claim 19, wherein, In step (1), the molar ratio of the cumene hydroperoxide to the a,a-dimethylbenzyl alcohol is (0.9-1.2):

1.

21. The method of claim 19, wherein, In step (1), the molar ratio of the cumene hydroperoxide to the a,a-dimethylbenzyl alcohol is (1.0-1.1):

1.

22. The method of any one of claims 1-3, wherein, In step (1), the acidic catalyst is selected from one or more of sulfuric acid, hydrochloric acid, phosphoric acid, perchloric acid, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, and trichloroacetic acid.

23. The method of claim 22, wherein, In step (1), the acidic catalyst is selected from one or more of sulfuric acid, hydrochloric acid, phosphoric acid, perchloric acid, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, and trichloroacetic acid.

24. The method of claim 23, wherein, In step (1), the acidic catalyst is selected from one or more of sulfuric acid, hydrochloric acid, phosphoric acid, perchloric acid, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, and trichloroacetic acid.

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