Preparation method of cumyl dihydroperoxide

Abstract

The invention provides a preparation method of cumyl dihydroperoxide, which comprises the following steps: continuously feeding a diisopropylbenzene raw material into a reactor, and carrying out oxidation reaction in the presence of alkali to obtain cumyl dihydroperoxide, wherein the reactor comprises N reaction sections distributed along the flowing direction of the diisopropylbenzene raw material, and N is an integer greater than or equal to 2; in the oxidation reaction process, alkali is added into the reactor from at least two reaction sections of the N reaction sections. When the method and the device are used for preparing the cumyl dihydroperoxide, the cumyl dihydroperoxide with higher selectivity can be obtained.

Description

Technical Field

[0001] The invention relates to a method for preparing cumene dihydroperoxide, and belongs to the technical field of organic chemistry. Background Art

[0002] The oxidation of diisopropylbenzene to prepare diisopropylbenzene hydroperoxide is an important link in the resorcinol industry chain. Its downstream products include acetone, resorcinol, BIPB and diisopropylbenzene.

[0003] When diisopropylbenzene undergoes oxidation reaction, an α-carbon on the isopropyl group of diisopropylbenzene is oxidized by oxygen to form a peroxide bond to obtain corresponding peroxidation products such as diisopropylbenzene hydroperoxide and isopropylbenzene dipydroperoxide. In the process of generating isopropylbenzene dipydroperoxide, benzyl alcohol impurities will also appear in the system. Excessive benzyl alcohol impurities will not only cause system blockage and affect production efficiency, but also reduce the selectivity of peroxide isopropylbenzene dipydroperoxide and reduce the reaction economy.

[0004] Therefore, how to effectively inhibit the generation of benzyl alcohol impurities and improve production efficiency and reaction economy is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0005] The main purpose of the present invention is to provide a method for preparing cumene hydroperoxide, which can effectively inhibit the formation of benzyl alcohol and improve the selectivity of cumene hydroperoxide, thereby improving the production efficiency and reaction economy in actual industry.

[0006] The present invention provides a method for preparing cumene dihydroperoxide, comprising the following steps:

[0007] The diisopropylbenzene raw material is continuously introduced into the reactor and subjected to oxidation reaction in the presence of a base to obtain diisopropylbenzene hydroperoxide;

[0008] Wherein, the reactor comprises N reaction sections distributed along the flow direction of the diisopropylbenzene raw material, where N is an integer greater than or equal to 2;

[0009] During the oxidation reaction, the base is added to the reactor from at least two of the N reaction stages.

[0010] In the method for preparing cumene dihydroperoxide as described above, the process of adding the base into the reactor from at least two of the N reaction sections comprises: for any of the reaction sections, continuously adding an alkali solution containing the base into the reaction section to achieve the addition of the base from the reaction section into the reactor.

[0011] In the method for preparing cumene dihydroperoxide as described above, the diisopropylbenzene raw material includes at least one of diisopropylbenzene and diisopropylbenzene hydroperoxide.

[0012] In the above-mentioned method for preparing cumene dihydroperoxide, during the oxidation reaction, for any of the reaction sections, the amount m of the alkali substance added to the reactor through the reaction section per hour on average satisfies:

[0013] 0.3A≤m≤3A,

[0014] in, ,

[0015] T is the reaction temperature of the reaction section, in °C;

[0016] C is 2~3.5, measured in mol / L;

[0017] Z is the anionic charge number of the base added to the reactor through the reaction section;

[0018] t is the residence time of the material in the reaction section, measured in h.

[0019] In the above-mentioned method for preparing cumene dihydroperoxide, for any reaction section, the material residence time t of the reaction section is 3 to 40 hours.

[0020] In the method for preparing cumene dihydroperoxide as described above, the reaction temperature T of the oxidation reaction in each of the reaction stages is 80-100° C.; and / or,

[0021] The reaction pressure of the oxidation reaction in each of the reaction sections is 200-600 kPa.

[0022] In the method for preparing cumene hydroperoxide as described above, N is an integer of 2 to 9.

[0023] In the method for preparing cumene dihydroperoxide as described above, in each of the reaction stages, the diisopropylbenzene raw material is brought into contact with a gas containing oxygen to carry out the oxidation reaction.

[0024] The preparation method of cumene dihydroperoxide as described above,

[0025] The oxygen-containing gas includes air;

[0026] After the oxidation reaction, the reactor generates tail gas, and the mass percentage of oxygen in the tail gas is 5-8wt%.

[0027] In the method for preparing cumene dihydroperoxide as described above, the reactor comprises N sub-reactors connected in sequence, and the reaction section is the sub-reactor.

[0028] The preparation method of cumene hydroperoxide provided by the present invention continuously reacts raw materials in multiple reactors in series, thereby improving the generation efficiency of the product cumene hydroperoxide and reducing the generation of by-product benzyl alcohol impurities, improving the problem of production equipment blockage caused by by-products, and improving the reaction economy and production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0030] Figure 1 The present invention provides a schematic structural diagram of a device for preparing cumene dihydroperoxide.

[0031] Description of reference numerals:

[0032] 1- first reactor;

[0033] 11-feeding port;

[0034] 12-feeding port;

[0035] 13-reaction liquid outlet;

[0036] 14-feeding port;

[0037] 2- Second reactor;

[0038] 21-feeding port;

[0039] 22-feeding port;

[0040] 23-reaction liquid outlet;

[0041] 24-feeding port;

[0042] 3- the third reactor;

[0043] 31-feeding port;

[0044] 32-feeding port;

[0045] 33-Product export;

[0046] 34-Feeding port.

[0047] The above drawings have shown clear embodiments of the present invention, which will be described in more detail below. These drawings and text descriptions are not intended to limit the scope of the present invention in any way, but to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] At present, in the process of preparing cumene hydroperoxide by oxidation of diisopropylbenzene, the hydroperoxide group will decompose to produce small molecular acids, and the continued presence of small molecular acids will inhibit the occurrence of oxidation reactions; in addition, small molecular acids will also be produced in the side reaction process of producing aldehydes and alcohols by oxidation of diisopropylbenzene, and these small molecular acids will lead to more side reactions. Therefore, alkali solution is often added to the raw material system to absorb the small molecular acids produced in the reaction solution to maintain the oxidation reaction. However, the addition of alkali solution will lead to the generation of a large amount of benzyl alcohol impurities, which will not only block the pipeline of the reaction equipment, shorten the equipment maintenance cycle, and reduce production efficiency, but also reduce the yield of cumene hydroperoxide.

[0050] Therefore, accurately controlling the amount of alkali solution added so that the alkali solution can react just with the small molecule acid in the reaction system is the key issue to reduce the production of by-product benzyl alcohol impurities and increase the production of the product cumene dihydroperoxide.

[0051] Based on this, the first aspect of the present invention provides a method for preparing cumene dihydroperoxide, comprising the following steps:

[0052] The diisopropylbenzene raw material is continuously introduced into the reactor and subjected to oxidation reaction in the presence of a base to obtain diisopropylbenzene hydroperoxide;

[0053] Wherein, the reactor comprises N reaction sections distributed along the flow direction of the diisopropylbenzene raw material, where N is an integer greater than or equal to 2;

[0054] During the oxidation reaction, base is added to the reactor from at least two of the N reaction stages.

[0055] The present invention uses diisopropylbenzene or diisopropylbenzene and diisopropylbenzene hydroperoxide as raw materials, uses alkali as catalyst, and carries out oxidation reaction under the catalytic action of the alkali to finally obtain diisopropylbenzene hydroperoxide. In the preparation method, the diisopropylbenzene raw materials continuously enter the reactor for oxidation reaction, thereby realizing mass production in industry.

[0056] During the reaction, the specific amount of the raw material can be determined according to the target yield of cumene hydroperoxide, and the amount of the base can be determined according to the specific amount of the raw material.

[0057] Wherein, the alkali includes at least one of sodium hydroxide, potassium hydroxide, potassium carbonate, and sodium carbonate. It is understood that the above-mentioned alkali can be diluted into an alkaline solution and added to at least two of the above-mentioned N reaction stages. The present invention does not specifically limit the mass percentage of the alkali solution, and it can be selected according to actual needs. For example, the mass percentage of the alkali solution can be 0.1~4wt%, including but not limited to 0.1wt%, 1wt%, 2wt%, 3wt%, 4wt% or the range composed of any two of them.

[0058] During the oxidation reaction of the raw material in the reactor, the raw material is divided into N reaction sections distributed along the flow direction of the raw material, where N is an integer greater than or equal to 2, and the base is added to the reactor from at least two of the N reaction sections. Specifically, the base can be added to each of the N reaction sections, or only to at least two reaction sections, and no base is added to the remaining reaction sections.

[0059] As mentioned above, the process of adding alkali from at least two of the N reaction sections to the reactor includes: for any reaction section, continuously adding alkali solution containing alkali to the reaction section to achieve adding alkali from the reaction section to the reactor.

[0060] Specifically, taking the example of three reaction sections distributed along the flow direction of the raw materials, the diisopropylbenzene raw material is oxidized with the alkali solution passed into the first reaction section to obtain a first reaction liquid, the first reaction liquid is oxidized with the alkali solution in the second reaction section to obtain a second reaction liquid, and the second reaction liquid is oxidized with the alkali solution in the third reaction section to obtain a reaction liquid including a diisopropylbenzene hydroperoxide product.

[0061] Since the amount of alkali solution in the first reaction section is insufficient to completely react all the added raw materials, the first reaction solution contains a large amount of unreacted raw materials in addition to a small amount of cumene hydroperoxide generated. Then, the first reaction solution and the alkali solution in the second reaction section undergo a second oxidation reaction after the oxidant is introduced, and part of the raw materials in the first reaction solution are oxidized to cumene hydroperoxide again to obtain a second reaction solution. By analogy, as the reaction solution in the previous oxidation reaction continuously enters the next oxidation reaction, the oxidation reaction is carried out under the condition of adding a portion of alkali solution until the Nth reaction section is reached. At this time, the last oxidation reaction of the raw materials is completed under the catalysis of the alkali solution in the Nth reaction section.

[0062] In detail, during the oxidation reaction, the present invention divides the total amount of alkali (i.e., the sum of the alkali used in N reaction stages) into multiple portions, and adds them in batches at different stages of the reaction, thereby avoiding the current process of adding all the alkali solution at the first reaction stage at one time, resulting in excess alkali content in the first few reaction stages, and thus causing the selectivity of the hydrogen peroxide group in the first few reaction stages to be low. Therefore, the preparation method of the present invention ensures that the acidic small molecules generated by oxidation are fully removed and the reaction rate can be maintained at a normal level. On the one hand, the selectivity of isopropylbenzene dihydroperoxide is increased and the generation of benzyl alcohol impurities is reduced, thereby improving the economy of the reaction. On the other hand, it also alleviates the phenomenon that the device needs to be stopped for maintenance due to blockage caused by excessive benzyl alcohol impurities, thereby improving the generation efficiency and reducing the maintenance cost.

[0063] After detection, it is found that in the Nth reaction stage, the reaction liquid includes a large amount of cumene hydroperoxide, and the content of benzyl alcohol impurities is extremely low. Therefore, the preparation method of the present invention can significantly improve the selectivity of cumene hydroperoxide and reduce the generation of benzyl alcohol impurities. Furthermore, under the premise of ensuring the long-term normal operation of the device without clogging, more cumene hydroperoxide can be produced, so the production efficiency and reaction economy are significantly improved.

[0064] In the present invention, the raw material includes at least one of diisopropylbenzene and diisopropylbenzene hydroperoxide. The diisopropylbenzene peroxide in the present invention is unilateral diisopropylbenzene peroxide, which is an intermediate product in the oxidation of diisopropylbenzene to diisopropylbenzene peroxide. The present invention uses at least one of diisopropylbenzene and diisopropylbenzene hydroperoxide to synthesize diisopropylbenzene hydroperoxide, and has a high raw material conversion rate.

[0065] In order to further ensure that the base can neutralize the small molecular acid produced in the oxidation reaction and inhibit the base from catalytically decomposing isopropylbenzene hydroperoxide to generate benzyl alcohol impurities, the present invention controls, during the above oxidation reaction, for any reaction section, the average amount m of the base added to the reactor through the reaction section per hour satisfies:

[0066] 0.3A≤m≤3A,

[0067] in, ,

[0068] T is the reaction temperature of the reaction section, in °C;

[0069] C is 2~3.5, measured in mol / L;

[0070] Z is the anionic charge number of the base added to the reactor through the reaction section;

[0071] t is the residence time of the material in the reaction section, measured in h.

[0072] In detail, T is the temperature at which the oxidation reaction occurs in any of the above-mentioned reaction sections. Generally, the temperature of each oxidation reaction is controlled to be the same. If there is a deviation, it can be brought in by the average temperature of the oxidation reactions of N reaction sections; through research and analysis, the inventors have determined that C represents the concentration of the hydrogen peroxide in the reaction liquid in the reaction section at the entrance of any of the above-mentioned reaction sections. The hydrogen peroxide mainly comes from the products of the oxidation reaction, namely, unilateral isopropyl hydroperoxide (diisopropyl hydroperoxide), diisopropyl hydroperoxide and other impurity components. The concentration of the hydrogen peroxide is calculated by adding the concentration of unilateral isopropyl hydroperoxide to twice the concentration of diisopropyl hydroperoxide. The concentration of the hydrogen peroxide can also be represented by the concentration of active oxygen in the reaction liquid in the above-mentioned reaction section. The active oxygen is an oxygen atom with oxidation activity in the hydrogen peroxide group. The concentration of active oxygen in the reaction liquid can be specifically determined by iodine titration; Z is the anion charge number of the base. For example, when the base is sodium hydroxide, Z is 1, and when the base is sodium carbonate, Z is 2.

[0073] When the amount of the alkali substance added to the reactor through the reaction section per hour on average is determined according to the above formula 1, the selectivity of cumene hydroperoxide can be further improved and the generation of benzyl alcohol impurities can be reduced.

[0074] In addition, the inventors have found that the residence time is also the key to improving the selectivity of cumene dihydroperoxide and reducing the selectivity of benzyl alcohol impurities. For any reaction section, the material residence time t of the reaction section is 3 to 20 hours. For example, the material residence time t of the reaction section includes but is not limited to 3 hours, 10 hours, 20 hours or a range consisting of any two of them.

[0075] The present invention further limits the temperature and pressure of the oxidation reaction to improve the selectivity of cumene dihydroperoxide and reduce the generation of benzyl alcohol impurities. In a specific embodiment, the temperature of the oxidation reaction is 80-100° C. For example, the temperature of the oxidation reaction includes but is not limited to 80° C., 85° C., 90° C., 95° C., 100° C. or a range consisting of any two of them.

[0076] In a specific embodiment, the pressure of the oxidation reaction is 200-600 kPa. For example, the pressure of the oxidation reaction includes but is not limited to 200 kPa, 300 kPa, 400 kPa, 500 kPa, 600 kPa or a range consisting of any two thereof.

[0077] In addition, the present invention does not impose any additional limitation on the number of reaction stages N. For example, N is 2 to 9. Specifically, the number of reaction stages can be determined according to the amount of raw materials. The larger the raw material system, the more reaction stages there are. In the above-mentioned method for preparing cumene hydroperoxide, the diisopropylbenzene raw material is contacted with a gas containing oxygen in each reaction stage for oxidation reaction.

[0078] During the oxidation reaction, the present invention does not limit the specific selection of the oxidant, but in order to avoid introducing too many impurities into the reaction system, air or oxygen can be used as the oxidant. It can be understood that when air is selected as the oxidant, it helps to further reduce costs.

[0079] It should be made clear that, because gas is introduced during the oxidation reaction to participate in the oxidation reaction, the reactor will produce tail gas after the oxidation reaction. Since the oxidation reaction is carried out at a certain temperature, the oxygen mass percentage in the tail gas discharged from the reactor can be controlled to be 5-8% after the oxidation reaction to ensure the continuity and safety of the reaction, and avoid the safety risks such as incomplete oxidation reaction or explosion and fire caused by too low or too high oxygen concentration in the system.

[0080] After the reaction is completed, a reaction system including cumene diperoxide is obtained. By post-treating the reaction system produced in the Nth reaction stage, cumene diperoxide can be separated from other components in the reaction system.

[0081] Specifically, the post-treatment includes sequentially performing extraction treatments on the reaction system.

[0082] Among them, the extraction treatment first uses a 3% to 15% sodium hydroxide solution for an extraction treatment. At this time, the product enters the sodium hydroxide solution to obtain a sodium hydroxide solution including the product, and the remaining phase is recycled to the above oxidation reaction. Next, at least one of a ketone with 4 to 10 carbon atoms, an ether with 4 to 10 carbon atoms, and an alcohol with 4 to 8 carbon atoms is used as an extractant to perform a secondary extraction treatment on the sodium hydroxide solution including the product obtained above. Methyl isobutyl ketone is most preferably used as the extractant. Through the extraction treatment, cumene diperoxide is dissolved in the extractant and separated from the sodium hydroxide solution to obtain a product of higher purity, cumene diperoxide. The secondary extraction temperature includes low-temperature extraction treatment and high-temperature extraction treatment. The above-mentioned low-temperature extraction is performed at a temperature of about 10 to 40°C, and the high-temperature extraction is performed at a temperature of 7 to 80°C.

[0083] As mentioned above, the reactor includes N sub-reactors connected in sequence, and the reaction section is the sub-reactor.

[0084] Specifically, the preparation method of cumene dihydroperoxide is carried out by a preparation device including a reactor, wherein the reactor includes N sub-reactors connected in series, each sub-reactor is filled with the reaction liquid in the reaction section, and the reaction liquid outlet of the previous sub-reactor is connected to the reaction liquid inlet of the next sub-reactor.

[0085] The sub-reactor comprises a reaction liquid outlet and a reaction liquid inlet. The reaction liquid outlet is used to output the reaction liquid in the current sub-reactor, and the reaction liquid inlet is used to receive the reaction liquid from the previous reactor.

[0086] Each sub-reactor also includes a feed port, which is used to add raw materials and alkali solution to the reactor. The present invention does not limit the number of feed ports, which can be one or more. Taking the first reactor as an example, when one feed port is included, both the raw materials and the alkali solution can be added to the reactor through the feed port; when multiple feed ports are included, the diisopropylbenzene raw material and the alkali solution can be added to the reactor through different feed ports. Of course, the oxidant can enter the reactor through the feed port.

[0087] The present invention does not impose any special limitation on the volume of each sub-reactor in the series-connected sub-reactors, and it can be selected according to actual conditions. The volumes of the sub-reactors can be the same or different.

[0088] Take N=2 as an example, Figure 1 As shown, the device of the present invention includes a first sub-reactor 1, a second sub-reactor 2 and a third sub-reactor 3 connected in series in sequence, wherein the reaction liquid outlet 13 of the first sub-reactor 1 is connected to the feeding port 22 of the second sub-reactor 2, and the reaction liquid outlet 13 is used to output the reaction liquid in the first sub-reactor to the second sub-reactor 2; the reaction liquid outlet 23 of the second sub-reactor 2 is connected to the feeding port 32 of the third sub-reactor 3, and the reaction liquid outlet 23 is used to output the reaction liquid in the second sub-reactor 2 to the third sub-reactor 3; and the product outlet 33 is used to output the reaction liquid in the third sub-reactor.

[0089] The first sub-reactor 1 includes three feeding ports, wherein the feeding port 11 is used to add diisopropylbenzene raw materials into the sub-reactor, the feeding port 12 is used to add alkali solution into the sub-reactor, and the feeding port 14 is used to introduce an oxidant into the sub-reactor;

[0090] The second sub-reactor 2 includes three feeding ports, the feeding port 21 is used to add alkali solution into the second sub-reactor, the feeding port 22 is used to add the reaction solution from the first sub-reactor into the second sub-reactor, and the feeding port 24 is used to introduce an oxidant into the second sub-reactor;

[0091] The third sub-reactor 3 includes three feeding ports, the feeding port 31 is used to add alkali solution into the third sub-reactor, the feeding port 32 is used to add the reaction solution from the second sub-reactor into the third sub-reactor, and the feeding port 34 is used to introduce the oxidant into the second sub-reactor.

[0092] Specifically, the process of continuously preparing cumene dihydroperoxide using the device is as follows: a raw material including a diisopropylbenzene raw material enters the first sub-reactor 1 from the feeding port 11 of the first sub-reactor, a first portion of alkali solution enters the first sub-reactor 1 from the feeding port 12 of the first sub-reactor, and then an oxidant is introduced from the feeding port 14 of the first sub-reactor, the oxidant, the raw material and the alkali solution undergo a first stage oxidation reaction in the first sub-reactor 1, and a reaction liquid of the first stage oxidation reaction is obtained at the reactor outlet 13;

[0093] The reaction liquid of the first stage oxidation reaction can directly enter the second sub-reactor from the reaction liquid outlet 13 of the first sub-reactor via the feeding port 22 of the second sub-reactor 2, and at the same time, the second portion of alkali solution is continuously introduced into the feeding port 21 of the second sub-reactor, and at the same time, air is introduced into the feeding port 23 of the second sub-reactor to carry out the second stage oxidation reaction, and the reaction liquid of the second stage oxidation reaction is obtained at the reactor outlet 23;

[0094] The second reaction liquid enters the third sub-reactor 3 directly from the reaction liquid outlet 23 of the second sub-reactor through the feeding port 32 of the second sub-reactor. At the same time, alkaline solution is continuously introduced into the feeding port 31 of the third sub-reactor, and oxidant is introduced into the feeding port 34 of the third sub-reactor to continue the third stage oxidation reaction. After the reaction is completed, a reaction liquid including cumene dipydroperoxide is obtained in the third sub-reactor 3, and the reaction liquid including cumene dipydroperoxide flows out from the product outlet 33 of the third sub-reactor and is collected.

[0095] This continuous generation of continuous input of raw materials and continuous output of products greatly reduces the non-reaction time during the reaction process, thereby significantly improving the reaction efficiency. In addition, in the continuous reaction process, the raw materials can be fully utilized, reducing the waste of resources.

[0096] By using the above-mentioned preparation device to prepare cumene dihydroperoxide, the reaction can be carried out in the direction of generating the target product cumene dihydroperoxide by controlling the amount of alkali solution added, which is beneficial to improving the selectivity of cumene dihydroperoxide preparation and thus improving the economic efficiency of the reaction. In addition, by using the above-mentioned preparation device to prepare cumene dihydroperoxide, the raw material can be continuously oxidized, which is beneficial to achieving mass production and thus improving production efficiency.

[0097] Furthermore, the preparation device further comprises a post-processing component, wherein the post-processing component comprises extraction towers connected in sequence, wherein the extraction tower is connected to the reaction liquid outlet of the Nth sub-reactor. By using the post-processing component to post-process the reaction liquid, it is beneficial to obtain cumene hydroperoxide with higher purity.

[0098] The technical solution of the present invention is further described below in conjunction with specific embodiments.

[0099] The reagents used in this example are as follows:

[0100] m-Diisopropylbenzene, purity 98%;

[0101] The equipment used in this embodiment is as follows:

[0102] Reactor, Yantai Ailang Machinery Technology Co., Ltd., design pressure: 1Mpa;

[0103] Example 1

[0104] The reaction assembly in the preparation device used in this embodiment includes two sub-reactors connected in series, wherein the reaction liquid outlet of the first sub-reactor is connected to the feeding port of the second sub-reactor. The first sub-reactor and the second sub-reactor each include three feeding ports, which are used to add raw materials, alkali solution and oxidant to the sub-reactors respectively.

[0105] The preparation method of this embodiment comprises the following steps:

[0106] 1) adding raw materials and alkali solution into the first sub-reactor and introducing air thereinto for oxidation reaction (i.e., the first reaction stage) to obtain a first reaction solution;

[0107] Among them, the volume of diisopropylbenzene raw material is 1m 3 , the molar concentration of diisopropylbenzene hydroperoxide in the raw material is 2.5 mol / L, and the molar concentration of diisopropylbenzene is 3 mol / L;

[0108] The alkali solution is 0.1% sodium hydroxide by mass percentage;

[0109] The reaction pressure of the oxidation reaction in the first sub-reactor is 300 kPa;

[0110] The reaction temperature of the oxidation reaction in the first sub-reactor was 90°C and the reaction time was 3h;

[0111] In the oxidation reaction in the first sub-reactor, the amount of alkali substance m added to the sub-reactor through the reaction section per hour on average is calculated by the following formula:

[0112] m=0.3A,

[0113] in, ; T is 80℃; C=2.5mol / L; Z is 1; t is 3h, C is 2.5mol / L. And the calculation shows that the outlet active oxygen molar concentration is 3.1mol / L

[0114] It is calculated that m=0.2325 for the first kettle, that is, the average amount of alkali added to the sub-reactor through the reaction section per hour is m=0.2325 mol.

[0115] During the oxidation reaction in the first sub-reactor, the tail oxygen concentration was controlled to be 5%.

[0116] 2) subjecting the first reaction solution and the alkali solution to an oxidation reaction in a second sub-reactor to obtain a product, cumene dihydroperoxide;

[0117] in,

[0118] The volume of the first reaction liquid in the second sub-reactor is 1m 3 , the reaction pressure of the oxidation reaction in the second sub-reactor is 300 kPa;

[0119] The reaction temperature of the oxidation reaction in the second sub-reactor is 80°C and the reaction time is 3h;

[0120] In the oxidation reaction in the second sub-reactor, the amount m of the alkali substance added to the sub-reactor through the reaction section per hour is calculated by the following formula:

[0121] m=0.3A,

[0122] in, ; T is 80°C; C is 3.1 mol / L; Z is 1; t is 3h. m=0.2775 is obtained, that is, the amount of alkali added to the sub-reactor through the reaction section per hour is 0.2775 mol.

[0123] During the oxidation reaction in the second sub-reactor, the tail oxygen concentration was controlled to be 5%.

[0124] Example 2

[0125] This embodiment is substantially the same as embodiment 1, except that, in step 1), the amount of the base substance m=A added to the reactor through the reaction section per hour on average;

[0126] In step 2), the amount of the alkali substance m=2A added into the reactor through the reaction section per hour on average.

[0127] Example 3

[0128] This embodiment is substantially the same as embodiment 1, except that, in step 1), the amount of the base substance m=8A added to the reactor through the reaction section per hour on average;

[0129] In step 2), the amount of the alkali substance m=6A added to the reactor through the reaction section per hour on average.

[0130] Example 4

[0131] This embodiment is basically the same as embodiment 1, except that, in this embodiment, the material residence time t in step 1) and step 2 is 6 hours.

[0132] Example 5

[0133] This embodiment is substantially the same as embodiment 1, except that, in this embodiment, the material residence time t in step 1) and step 2) is 25 h.

[0134] Example 6

[0135] This embodiment is substantially the same as Embodiment 1, except that, in this embodiment, C=3 in Step 1) and Step 2).

[0136] Example 7

[0137] This embodiment is substantially the same as Embodiment 1, except that, in this embodiment, C=4 in Step 1) and Step 2).

[0138] Comparative Example 1

[0139] This comparative example is substantially the same as Example 1, except that in this comparative example, the amount of total alkali used in step 1) and step 2) of Example 1 is added to the first reaction stage at one time.

[0140] Test example

[0141] The reaction liquid including the product cumene hydroperoxide collected at the product outlet of the reactor in the embodiment and the comparative example was subjected to liquid phase analysis, specifically, the molar amount of cumene hydroperoxide in the reaction liquid was obtained by using a Shimadzu LC20A liquid chromatograph and a Shimadzu phenyl column under the conditions of a ratio of water to acetonitrile in the mobile phase of 1:1, an analysis temperature of 30°C, and an analysis time of 2h.

[0142] The selectivity of cumene dihydroperoxide in the embodiment and the comparative example was calculated according to the following formula, and the results are shown in Table 1.

[0143] Selectivity calculation formula: selectivity of isopropylbenzene dihydroperoxide molar amount = (molar amount of isopropylbenzene dihydroperoxide in the reaction solution) / (molar amount of diisopropylbenzene in the raw material + molar amount of diisopropylbenzene hydroperoxide in the raw material - molar amount of diisopropylbenzene in the output - molar amount of diisopropylbenzene hydroperoxide in the output);

[0144] The selectivity calculation results are shown in Table 1.

[0145] Table 1

[0146]

[0147] As can be seen from the table, Examples 1-7 have higher selectivity for cumene dipyroxide than Comparative Example 1. In addition, Examples 1-2, 4, and 6 also show higher selectivity for cumene dipyroxide by further controlling the amount of the alkali substance added to the reactor through the reaction section per hour in the oxidation reaction, the material residence time, and the concentration of active oxygen in the reaction liquid in the reaction section relative to Examples 3, 5, and 7. Therefore, the present application is beneficial to improving the selectivity of the reaction liquid for cumene dipyroxide and reducing the generation of side reactions by setting a plurality of sub-reactors connected in series and adding alkali solution to each sub-reactor to carry out the oxidation reaction of the reaction liquid for cumene dipyroxide.

[0148] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing cumene dihydroperoxide, characterized in that: The following steps are involved: The diisopropylbenzene raw material is continuously introduced into the reactor and subjected to oxidation reaction in the presence of a base to obtain diisopropylbenzene hydroperoxide; Wherein, the reactor comprises N reaction sections distributed along the flow direction of the diisopropylbenzene raw material, where N is an integer greater than or equal to 2; During the oxidation reaction, the base is added to the reactor from at least two of the N reaction stages.

2. The method for preparing cumene dihydroperoxide according to claim 1, characterized in that: The process of adding the alkali from at least two of the N reaction sections to the reactor comprises: for any of the reaction sections, continuously adding an alkali solution containing the alkali to the reaction section to achieve adding the alkali from the reaction section to the reactor.

3. The method for preparing cumene dihydroperoxide according to claim 1 or 2, characterized in that: The diisopropylbenzene raw material includes at least one of diisopropylbenzene and diisopropylbenzene hydroperoxide.

4. The method for preparing cumene hydroperoxide according to any one of claims 1 to 3, characterized in that: During the oxidation reaction, for any of the reaction sections, the amount m of the alkali added to the reactor through the reaction section per hour on average satisfies: 0.3A≤m≤3A, in, , T is the reaction temperature of the reaction section, in °C; C is 2-3.5, in mol / L; Z is the anionic charge number of the base added to the reactor through the reaction section; t is the residence time of the material in the reaction section, measured in h.

5. The method for preparing cumene hydroperoxide according to any one of claims 1 to 4, characterized in that: For any reaction section, the material residence time t of the reaction section is 3~20h.

6. The method for preparing cumene dihydroperoxide according to any one of claims 1 to 5, characterized in that: The reaction temperature T of the oxidation reaction in each reaction stage is 80-100° C.; and / or, The reaction pressure of the oxidation reaction in each of the reaction sections is 200-600 kPa.

7. The method for preparing cumene dihydroperoxide according to any one of claims 1 to 6, characterized in that: The N is an integer from 2 to 9.

8. The method for preparing cumene hydroperoxide according to any one of claims 1 to 7, characterized in that: In each of the reaction stages, the diisopropylbenzene raw material is brought into contact with a gas containing oxygen to carry out the oxidation reaction.

9. The method for preparing cumene dihydroperoxide according to claim 8, characterized in that: The oxygen-containing gas includes air; And / or, after the oxidation reaction, the reactor generates tail gas, and the mass percentage of oxygen in the tail gas is 5-8wt%.

10. The method for preparing cumene dihydroperoxide according to any one of claims 1 to 3, characterized in that: The reactor comprises N sub-reactors connected in sequence, and the reaction section is the sub-reactor.

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