Preparation method, oxidation reaction device and production system of m-diisopropylbenzene dihydroperoxide

Abstract

The invention provides a preparation method, an oxidation reaction device and a production system of m-diisopropylbenzene dihydroperoxide, and relates to the technical field of organic synthesis. The preparation method of the m-diisopropylbenzene dihydrogen peroxide comprises the following steps: in the presence of alkali liquor, carrying out oxidation reaction on m-diisopropylbenzene and oxygen to obtain first feed liquid of the m-diisopropylbenzene dihydrogen peroxide; wherein in the oxidation reaction process, the pH value of a reaction system is controlled to be 9-11, and the viscosity of the reaction system is controlled to be smaller than 10 mPa.s. According to the preparation method of the m-diisopropylbenzene hydrogen peroxide, the pH value in the reaction liquid is regulated and controlled on line, and the generation of high-viscosity components is reduced, so that normal operation of the oxidation reaction of m-diisopropylbenzene and oxygen is ensured, side reactions are weakened, the mass transfer effect is enhanced, and the reaction efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of organic synthesis, and in particular to a preparation method, an oxidation reaction device and a production system of m-diisopropylbenzene dihydroperoxide. Background Art

[0002] Resorcinol is a white flake or powdery crystal with a melting point of 109-111°C. It is easily soluble in water, ethanol, ether and other solvents. Its molecular formula is C 6 H 6 O 2 It is an important organic chemical intermediate. It is mainly used in the industry for the polymerization production of resorcinol formaldehyde resin and used as a rubber adhesive in the tire industry. In addition, resorcinol is widely used as a raw material in the pesticide, cosmetics, dye and other industries.

[0003] At present, the main production processes of resorcinol in the world are oxidation, hydrolysis and sulfonation alkali fusion. Compared with hydrolysis and sulfonation alkali fusion, oxidation has the advantages of low cost and less waste. The oxidation process has two steps: oxidation of m-diisopropylbenzene and acid hydrolysis of peroxide. In the oxidation process of m-diisopropylbenzene, there are many side reactions and the by-products are complex. The reaction usually does not completely convert the raw materials, and the reaction products need to be returned to the oxidation reaction after the extraction and separation process. There are problems such as increased by-products and affected viscosity and selectivity of the reaction solution.

[0004] In particular, during the oxidation of m-diisopropylbenzene, there are many side reactions, the by-products are complex, and some incompletely reacted intermediates exist in the reaction products. After the extraction and separation process, the reaction products need to be recycled to the oxidation reaction. The high-viscosity by-products in the recycled feed liquid and the newly generated high-viscosity by-products will affect the viscosity and selectivity of the reaction liquid. The lower the viscosity of the reaction liquid, the better the reaction effect. The increase in the viscosity of the reaction liquid will lead to uneven mixing of the reaction liquid, the inability of the reactants to contact well, and the reduction of the reaction selectivity. The higher viscosity will also lead to the deterioration of the local flow effect of the reaction liquid, local over-reaction (product decomposition or polymerization) or local non-reaction (low conversion rate and selectivity).

[0005] US3950431A discloses a method for removing impurities from an oxidation liquid, wherein an alkaline aqueous solution containing 10 to 80% methanol or ethanol is used to extract and reuse the oil phase, and byproducts such as small molecular weight ketones and benzyl alcohols are removed. US3993696A discloses a method for recovering diisopropylbenzene monoperoxide, wherein the small molecular weight ketones and benzyl alcohol products are removed by steam stripping and then the isopropyl hydroperoxide isopropylbenzene and diisopropylbenzene are reused. Although byproducts such as small molecular weight ketones and benzyl alcohols are removed by the above method, there are still problems of decreased selectivity and equipment blockage during the oxidation reaction. CN118108647A discloses a method for continuous preparation of diisopropylbenzene hydroperoxide, wherein the diisopropylbenzene hydroperoxide polymer produced by the reaction is removed by using a macroporous adsorption resin and then the monoisopropylbenzene hydroperoxide, diisopropylbenzene and other substances are reused. The above method detects the impurity content in the reaction product during the post-treatment process to separate ketones, benzyl alcohol by-products and peroxide polymer by-products in the reaction process, which has a certain hysteresis and cannot accurately control the reaction effect. The reaction products decompose or polymerize, resulting in low selectivity.

[0006] By increasing stirring, the mixing effect of the reaction liquid can be improved and the viscosity of the reaction liquid can be reduced to a certain extent. However, due to the presence of a large amount of peroxide in the reactor, long-term stirring or high-speed stirring will cause the peroxide to decompose, leading to safety issues. Therefore, a new continuous preparation method of diisopropylbenzene hydroperoxide is needed, which can detect the reaction by-products online and regulate them in real time to reduce the generation of high-viscosity by-products, and optimize the reaction effect without changing the reaction composition.

[0007] In view of this, the present invention is proposed. Summary of the invention

[0008] The object of the present invention is to provide a preparation method, oxidation reaction device and production system of m-diisopropylbenzene dihydroperoxide. The preparation method, oxidation reaction device and production system of the present invention effectively solve the problems of increasing high viscosity byproducts (mainly 1,3-di(2-hydroxy-2-propyl)benzene and peroxide polymers) in the preparation of m-diisopropylbenzene dihydroperoxide by reacting m-diisopropylbenzene with oxygen, the inability to ensure the flow effect of the reaction liquid, and the poor local mass transfer effect.

[0009] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0010] In a first aspect, the present invention provides a method for preparing m-diisopropylbenzene dihydroperoxide, the method for preparing m-diisopropylbenzene dihydroperoxide comprising the following steps:

[0011] In the presence of an alkali solution, m-diisopropylbenzene is oxidized with oxygen to obtain a first feed liquid containing m-diisopropylbenzene dihydroperoxide with a content of more than 50 wt %;

[0012] Wherein, during the oxidation reaction, the pH of the reaction system is controlled to be 9-11, and the viscosity of the reaction system is controlled to be less than 10 mPa·s.

[0013] Preferably, the first feed liquid further includes: m-diisopropylbenzene, 1,3-di(2-hydroxy-2-propyl)benzene, peroxide polymers and other by-products.

[0014] Preferably, the other by-products are selected from any one of m-diisopropylbenzene monohydroperoxide, 3-(2-hydroxy-2-propyl)isopropylbenzene hydroperoxide or 3-(2-hydroxy-2-propyl)isopropylbenzene, or a combination of at least two thereof.

[0015] Preferably, the first liquid comprises, by mass percentage, 65-80% of m-diisopropylbenzene hydroperoxide, 3-10% of m-diisopropylbenzene, 0-2% of 1,3-di(2-hydroxy-2-propyl)benzene, 3-8% of peroxide polymer and 10-18% of other by-products.

[0016] Preferably, during the oxidation reaction, the reaction system is controlled by controlling the feed amount of the alkali solution.

[0017] Preferably, the mass ratio of the alkali solution to m-diisopropylbenzene is (0.05-0.5):1.

[0018] Preferably, the alkali solution is an aqueous alkali solution with a solid content of 0 to 5 wt%.

[0019] Preferably, the base is selected from any one or a combination of at least two of alkali metal hydroxides, alkali metal carbonates or alkali metal bicarbonates, preferably any one or a combination of at least two of sodium hydroxide, sodium bicarbonate, sodium carbonate, potassium hydroxide, potassium carbonate or potassium bicarbonate.

[0020] Preferably, during the oxidation reaction, the viscosity of the reaction system is controlled by controlling the stirring speed;

[0021] Preferably, the stirring speed is 50-150 rpm.

[0022] Preferably, the pressure of the oxidation reaction is 200-600 kPa.

[0023] Preferably, the temperature of the oxidation reaction is 70-90°C.

[0024] Preferably, the residence time of the oxidation reaction is 10 to 20 hours.

[0025] Preferably, the method for preparing m-diisopropylbenzene dihydroperoxide further comprises the following separation step:

[0026] (a) adding m-diisopropylbenzene to the first feed liquid to separate and obtain a second feed liquid and a third feed liquid;

[0027] Wherein, the second feed liquid includes: organic acid salt and peroxide polymer; the third feed liquid includes: m-diisopropylbenzene, 1,3-di(2-hydroxy-2-propyl)benzene, peroxide polymer and other by-products;

[0028] (b) adding alkali solution to the third feed liquid to perform a first extraction to obtain a fourth feed liquid and a fifth feed liquid;

[0029] The fourth liquid includes: m-diisopropylbenzene dihydroperoxide, peroxide polymer, water and other by-products; the fifth liquid includes: m-diisopropylbenzene, 1,3-di(2-hydroxy-2-propyl)benzene peroxide polymer and other by-products;

[0030] (c) transporting the fourth feed liquid to an extraction tower for secondary extraction to separate the m-diisopropylbenzene dihydroperoxide from the alkali solution.

[0031] Preferably, in step (a), the mass ratio of the first feed liquid to m-diisopropylbenzene is 1:(0.5-5).

[0032] Preferably, in step (a), the second liquid comprises, by mass percentage, 1 to 10% of an organic acid salt and 1 to 10% of a peroxidized polymer.

[0033] Preferably, in step (a), the organic acid salt comprises any one of sodium phenolate, sodium formate, sodium acetate or sodium propionate, or a combination of at least two thereof.

[0034] Preferably, in step (a), the third liquid comprises, by mass percentage, 40-55% of m-diisopropylbenzene, 0-2% of 1,3-di(2-hydroxy-2-propyl)benzene, 35-60% of m-diisopropylbenzene dihydroperoxide, 1-5% of peroxide polymer, and 2-9% of other by-products;

[0035] Preferably, in step (b), the mass ratio of the third liquid to the neutralizing alkali solution is 1:(1-5).

[0036] Preferably, in step (b), the alkali solution is an aqueous solution of alkali with a solid content of 5 to 15 wt%.

[0037] Preferably, in step (b), the base is selected from any one or a combination of at least two of alkali metal hydroxides, alkali metal carbonates or alkali metal bicarbonates, preferably sodium hydroxide.

[0038] Preferably, in step (b), the fourth liquid comprises, by mass percentage, 10-30% of m-diisopropylbenzene dihydroperoxide, 0-1% of peroxide polymer and 65-75% of water.

[0039] Preferably, in step (b), the fifth liquid comprises, by mass percentage, 80-90% of m-diisopropylbenzene, 0-2% of 1,3-di(2-hydroxy-2-propyl)benzene, 1-5% of peroxide polymer and 5-13% of other by-products.

[0040] Preferably, in step (b), the fifth liquid obtained can be used as a raw material and circulated to the oxidation reaction step to undergo an oxidation reaction with oxygen to obtain a first liquid containing more than 65 wt % of m-diisopropylbenzene dihydroperoxide.

[0041] In a second aspect, the present invention provides an oxidation reaction device, which includes an oxidation reaction kettle body, a driving stirring device, an online viscosity detection device and an online pH detection device;

[0042] The driving and stirring device comprises a driving motor, a stirring motor and a stirring paddle, wherein the driving motor is fixedly mounted on the outer upper end of the oxidation reactor body, and the stirring paddle is connected to the stirring motor and is located inside the oxidation reactor body;

[0043] Wherein, the online viscosity detection device is connected to the driving stirring device and is used for online detection of the viscosity of the process system of the oxidation reaction of m-diisopropylbenzene and oxygen.

[0044] Preferably, a guide plate is provided inside the oxidation reactor body, and a heat exchange coil is provided inside the guide plate for heat exchange.

[0045] Preferably, the width of the guide plate is 50-80% of the inner diameter of the oxidation reactor;

[0046] Preferably, the oxidation reactor body further comprises a feed port, and the feed port is located on one side of the upper portion of the oxidation reactor body, and is used to transport alkali solution and / or m-diisopropylbenzene into the interior of the oxidation reactor body.

[0047] Preferably, a transverse pipe is arranged above the interior of the oxidation reactor body, and one end of the transverse pipe is connected to the feed port of the oxidation reactor body, and four feed ports are arranged below the transverse pipe for transporting alkali solution and / or m-diisopropylbenzene to the interior of the oxidation reactor body.

[0048] Among the four feed ports, the middle two feed ports are located to input alkali solution and / or m-diisopropylbenzene back-jacket liquid into the reaction zone inside the guide plate; the outer two feed ports transport the self-circulating liquid after heat exchange to the circulation zone outside the guide plate to provide a circulation effect.

[0049] Preferably, the oxidation reactor body further comprises a product port, and the product port is located at the other side of the lower portion of the oxidation reactor body, and is used to transport the first feed liquid containing m-diisopropylbenzene dihydroperoxide to the outside.

[0050] Preferably, the oxidation reactor body further comprises an air inlet, and the air inlet is located below the oxidation reactor body, and the air inlet is used to transport oxygen-containing gas, preferably air, into the interior of the oxidation reactor body.

[0051] Preferably, the air inlet is fixedly connected with a gas distribution device;

[0052] Wherein, the gas distribution device is an annular gas distribution device, and the gas distribution device comprises an annular body of the distribution device, an air inlet pipe, a distribution pipe and at least one air hole arranged on the annular body;

[0053] Preferably, the oxidation reactor body further includes a tail gas outlet, and the tail gas outlet is arranged on one side of the top of the oxidation reactor body.

[0054] In a third aspect, the present invention provides a system for producing m-diisopropylbenzene dihydroperoxide, the system comprising a feed unit, the oxidation reaction device described in the second aspect, and a separation system connected in sequence.

[0055] Further, the feed unit includes a m-diisopropylbenzene feed unit, an alkali solution feed unit and an oxygen-containing gas feed unit;

[0056] Wherein, the m-diisopropylbenzene feeding unit comprises a m-diisopropylbenzene recycle tank and a m-diisopropylbenzene delivery pipeline, and the m-diisopropylbenzene delivery pipeline is connected to the feed port of the oxidation reaction device; the alkali solution feeding unit comprises an alkali solution raw material tank and an alkali solution delivery pipeline, and the alkali solution delivery pipeline is connected to the feed port of the oxidation reaction device; the oxygen-containing gas feeding unit comprises an oxygen-containing gas storage tank and an oxygen-containing gas delivery pipeline, and the oxygen-containing gas delivery pipeline is connected to the gas inlet of the oxidation reaction device;

[0057] And / or, the product outlet of the oxidation reaction device is connected to the separation system via a pipeline, and the first feed liquid containing m-diisopropylbenzene dihydroperoxide is transported to the separation system.

[0058] Furthermore, the product outlet of the oxidation reaction device is connected to the separation system through a pipeline, and the first feed liquid containing m-diisopropylbenzene dihydroperoxide is transported to the separation system.

[0059] Preferably, the separation system comprises any one of an extraction device, a filtration device, an adsorption device, a distillation device or a crystallization device.

[0060] Compared with the prior art, the present invention has the following beneficial effects:

[0061] (1) The method of the present invention eliminates the accumulation of organic acids during the reaction process by detecting the pH of the reaction solution and replenishing the alkali solution in time, effectively controls the decomposition of m-diisopropylbenzene dihydroperoxide, and increases the concentration of the reaction product.

[0062] (2) The method of the present invention timely adjusts the mixing effect of the reaction liquid by detecting the viscosity of the reaction liquid, weakens the generation of high-viscosity by-products in the reaction, thereby reducing the viscosity of the reaction liquid, avoiding the local increase of high-viscosity heavy components to a certain extent, and improving the reaction effect;

[0063] (3) The present invention detects the pH and viscosity of the oxidation reaction through an online detection system, the pH is regulated online through an oxidation feed regulating valve, and the viscosity is regulated by stirring of a stirring motor; after optimizing the reaction control, the selectivity is increased to more than 95%, the diisopropylbenzene content in the reaction discharge is less than 6%, the DHP content is higher than 75%, and the peroxide polymer content is less than 5%. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0065] Figure 1 It is a schematic structural diagram of the oxidation reaction device of the present invention.

[0066] Figure 2 The present invention is a schematic structural diagram of the production system of m-diisopropylbenzene dihydroperoxide.

[0067] Figure 3 A top view of the guide plate provided by the present invention.

[0068] Figure 4 This is a schematic diagram of the gas distributor of the present invention. DETAILED DESCRIPTION

[0069] Unless otherwise defined herein, scientific and technological terms used in conjunction with the present invention shall have the meanings commonly understood by those of ordinary skill in the art. The meaning and scope of the terms should be clear, however, in the case of any potential ambiguity, the definitions provided herein take precedence over any dictionary or external definitions. In this application, unless otherwise stated, the use of "or" means "and / or". In addition, the use of the term "including" and other forms is non-limiting.

[0070] It should be noted that specific details are described in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in a variety of other ways different from those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0071] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than 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.

[0072] In a first aspect, the present invention provides a method for preparing m-diisopropylbenzene dihydroperoxide, the method for preparing m-diisopropylbenzene dihydroperoxide comprising the following steps:

[0073] In the presence of an alkali solution, m-diisopropylbenzene and oxygen undergo an oxidation reaction to obtain a first feed solution containing m-diisopropylbenzene dihydroperoxide with a content of more than 50 wt %.

[0074] In the present invention, the preparation method of m-diisopropylbenzene dihydroperoxide controls the alkali liquid feed regulating valve of the oxidation reaction device online by detecting pH, controls the stirring motor of the oxidation reaction device online by detecting viscosity, regulates the pH value in the reaction liquid online and reduces the generation of high-viscosity components, thereby ensuring the normal operation of the reaction, reducing the occurrence of side reactions, enhancing the mass transfer effect and improving the reaction efficiency.

[0075] As an optional embodiment, during the oxidation reaction, the pH of the reaction system is controlled to be 9-11, for example, 9, 9.2, 9.4, 9.6, 9.8, 10, 10.2, 10.4, 10.6, 10.8, 11, etc.

[0076] In the present invention, the preparation method is to set an online pH detection device in the oxidation reaction device to realize online detection of the pH of the system during the reaction process, and to control the alkali solution feed regulating valve of the oxidation reaction device online so that the pH of the reaction system is maintained at 9-11. When the pH of the solution deviates, the alkali solution feed valve is controlled to open so that the pH of the reaction system is maintained at 9-11.

[0077] It should be noted that if the pH of the system during the oxidation reaction is greater than 11, the alkali content (such as sodium hydroxide) in the reaction system is too high, which may cause the peroxide to decompose (generate methanol), reduce the yield, and increase the amount of benzyl alcohol or acetophenone substances, affecting the reaction effect; if the pH of the system during the oxidation reaction is less than 9, the generated organic acid cannot be neutralized in time, and the organic acid enters the alkali extraction with the oil phase in the subsequent water separation step, reducing the alkali extraction effect. In addition, too high an organic acid concentration may produce precipitation in the subsequent separation process. The stability of peroxides: strong acid < strong base < weak acid < neutral < weak base, so when the pH is less than 9, the stability of peroxides will also decrease.

[0078] As an optional embodiment, during the oxidation reaction, the viscosity of the reaction system is controlled to be less than 10 mPa·s, for example, it may be 9.9 mPa·s, 9.5 mPa·s, 9.0 mPa·s, 8.5 mPa·s, 8.0 mPa·s, 7.5 mPa·s, 7.0 mPa·s, 6.5 mPa·s, 6.0 mPa·s, 5.5 mPa·s, 5.0 mPa·s, etc.

[0079] In the present invention, the preparation method achieves the purpose of online detection of the viscosity of the system during the reaction process by setting an online viscosity detection device in the oxidation reaction device, and online controls the stirring motor of the oxidation reaction device to maintain good fluidity of the material in the reaction device.

[0080] It should be noted that if the viscosity value of the system during the reaction is greater than 10mPa·s, the material in the reaction device may have a problem of low local fluidity. Since the material cannot flow well, the reaction selectivity is reduced. At this time, the stirring is controlled to enhance the flow effect of the oxidation liquid and reduce the production of high-viscosity by-products in the reaction, thereby reducing the viscosity. In addition, if it is not controlled, the high-viscosity component increases. Once the viscosity exceeds 15mPa·s, it will not only affect the selectivity of the reaction, but also reduce the conveying effect of the oxidation discharge pump, affecting the head, conveying flow, etc.

[0081] As an optional embodiment, the present invention adopts a method of online detection and regulation of the viscosity of the system during the reaction, and simultaneously online detection and regulation of the pH of the system during the reaction, so that the content of meta-diisopropylbenzene dihydroperoxide in the first slurry obtained by the oxidation reaction of meta-diisopropylbenzene and oxygen is increased to more than 50wt%, for example, it can be 50wt%, 55wt%, 60wt%, 65wt%, 70wt%, 75wt%, 80wt%, 85wt%, 90wt%, etc.

[0082] As an optional embodiment, the first feed liquid also includes: m-diisopropylbenzene, 1,3-di(2-hydroxy-2-propyl)benzene, peroxide polymers and other by-products.

[0083] As an optional embodiment, the other types of by-products are selected from any one or a combination of at least two of m-diisopropylbenzene monohydroperoxide, 3-(2-hydroxy-2-propyl)isopropylbenzene hydroperoxide or 3-(2-hydroxy-2-propyl)isopropylbenzene.

[0084] As an optional embodiment, the first slurry comprises, by mass percentage, 65-80% of m-diisopropylbenzene hydroperoxide, 3-10% of m-diisopropylbenzene, 0-2% of 1,3-di(2-hydroxy-2-propyl)benzene, 3-8% of peroxide polymer, and 10-18% of other by-products.

[0085] Taking the total mass of the first liquid as 100%, the content of m-diisopropylbenzene hydroperoxide is 65-80%, for example, 65%, 66%, 68%, 70%, 72%, 74%, 75%, 76%, 78%, 80%, etc.

[0086] Taking the total mass of the first liquid feed as 100%, the content of m-diisopropylbenzene therein is 3-10%, for example, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc.

[0087] Taking the total mass of the first liquid as 100%, the content of the peroxidized polymer is 3-8%, for example, 3%, 4%, 5%, 6%, 7%, 8%, etc.

[0088] Taking the total mass of the first liquid feed as 100%, the content of other by-products is 10-18%, for example, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, etc.

[0089] As an optional embodiment, during the oxidation reaction, the reaction system is controlled by controlling the feed amount of the alkali solution.

[0090] As an optional embodiment, the mass ratio of the alkali solution to m-diisopropylbenzene is (0.05-0.5):1, for example, it can be 0.05:1, 0.08:1, 0.1:1, 0.15:1, 0.2:1, 0.25:1, 0.3:1, 0.35:1, 0.4:1, 0.45:1, 0.5:1, etc.

[0091] As an optional embodiment, the alkali solution is an aqueous solution of alkali with a solid content of 0 to 5wt%; wherein the solid content of the alkali can be, for example, 0wt%, 0.1wt%, 0.2wt%, 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, 5wt% and the like.

[0092] As an optional embodiment, the base is selected from any one of alkali metal hydroxides, alkali metal carbonates or alkali metal bicarbonates, or a combination of at least two of them, and is preferably any one of sodium hydroxide, sodium bicarbonate, sodium carbonate, potassium hydroxide, potassium carbonate or potassium bicarbonate, or a combination of at least two of them.

[0093] As an optional embodiment, during the oxidation reaction, the viscosity of the reaction system is controlled by controlling the rotation speed of the stirring.

[0094] It should be noted that the stirring speed is one of the factors that affect the viscosity. By increasing the stirring speed, the fluidity and mixing effect of the reaction liquid can be improved, and the production of high-viscosity by-products in the reaction can be reduced, thereby reducing the viscosity. In addition, the increase in the stirring speed will bring more shear and agitation to the liquid, accelerate the interaction of molecules, and reduce the viscosity of the liquid. However, due to the presence of a large amount of unstable peroxides in the oxidation reaction device, long-term stirring or high-speed stirring will cause the peroxide to decompose, leading to safety problems, so intermittent stirring and speed control are required.

[0095] As an optional implementation, when the viscosity of the reaction system is greater than 10 mPa·s, stirring is started; and when the viscosity of the reaction system is less than or equal to 5 mPa·s, stirring is turned off.

[0096] It should be noted that the stirring device described in the present invention is divided into motor-driven and non-driven modes. As the reaction proceeds, the viscosity of the system gradually increases. When the viscosity of the reaction liquid is greater than 10 mPa·s, the motor is started for stirring. By turning on the stirring, the gas-liquid mixing state inside the reaction device is improved, the reaction effect is adjusted, the viscosity is reduced, and the reaction effect is enhanced. When the viscosity of the reaction liquid is reduced to 5 mPa·s or less by stirring, the oxidation liquid is in a good state of relaxation and no stirring is required, that is, the stirring is turned off.

[0097] As an optional embodiment, when starting stirring, the stirring speed is 50-150 rpm, for example, it can be 50 rpm, 60 rpm, 70 rpm, 80 rpm, 90 rpm, 100 rpm, 110 rpm, 120 rpm, 130 rpm, 140 rpm, 150 rpm, etc.

[0098] As an optional embodiment, the pressure of the oxidation reaction is 200-600 kPa, for example, it can be 200 kPa, 250 kPa, 300 kPa, 350 kPa, 400 kPa, 450 kPa, 500 kPa, 550 kPa, 600 kPa, etc.

[0099] As an optional embodiment, the temperature of the oxidation reaction is 70-90°C, for example, it can be 70°C, 72°C, 74°C, 75°C, 76°C, 78°C, 80°C, 82°C, 84°C, 85°C, 86°C, 88°C, 90°C, etc.

[0100] As an optional embodiment, the residence time of the oxidation reaction is 10 to 20 hours, for example, it can be 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, etc.

[0101] As an optional embodiment, the preparation method further comprises the following separation step:

[0102] (a) adding m-diisopropylbenzene to the first feed liquid to separate and obtain a second feed liquid and a third feed liquid;

[0103] Wherein, the second feed liquid includes: organic acid salt and peroxide polymer; the third feed liquid includes: m-diisopropylbenzene, 1,3-di(2-hydroxy-2-propyl)benzene, peroxide polymer and other by-products;

[0104] (b) adding alkali solution to the third feed liquid to perform a first extraction to obtain a fourth feed liquid and a fifth feed liquid;

[0105] The fourth liquid comprises: m-diisopropylbenzene dihydroperoxide, peroxide polymer, water and other by-products; the fifth liquid comprises: m-diisopropylbenzene, 1,3-di(2-hydroxy-2-propyl)benzene, peroxide polymer and other by-products;

[0106] (c) transporting the fourth feed liquid to an extraction tower for secondary extraction to separate the m-diisopropylbenzene dihydroperoxide from the alkali solution.

[0107] In the present invention, in step (a), diisopropylbenzene is added to the first liquid to promote separation effect; in step (b), since diisopropylbenzene is immiscible with water, the organic acid salt in the water is separated; wherein the organic acid salt is generated during the oxidation reaction.

[0108] As an optional embodiment, the mass ratio of the first liquid to m-diisopropylbenzene is 1:(0.5-5), for example, it can be 1:0.5, 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, etc.

[0109] As an optional embodiment, in step (a), the second liquid comprises, by mass percentage, 1 to 10% of an organic acid salt and 1 to 10% of a peroxidized polymer.

[0110] Taking the total mass of the second liquid as 100%, the content of the organic acid salt is 1-10%, for example, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc.

[0111] Taking the total mass of the second liquid as 100%, the content of the peroxidized polymer is 1-10%, for example, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc.

[0112] As an optional embodiment, in step (a), the organic acid salt includes any one of sodium phenolate, sodium formate, sodium acetate or sodium propionate, or a combination of at least two thereof.

[0113] As an optional embodiment, in step (a), the third liquid comprises, by mass percentage, 40-55% of m-diisopropylbenzene, 0-2% of 1,3-di(2-hydroxy-2-propyl)benzene, 35-60% of m-diisopropylbenzene hydroperoxide, 1-5% of peroxide polymer, and 2-9% of other by-products.

[0114] Taking the total mass of the third liquid feed as 100%, the content of m-diisopropylbenzene therein is 40-55%, for example, 40%, 42%, 44%, 45%, 46%, 48%, 50%, 52%, 54%, 55%, etc.

[0115] Taking the total mass of the third liquid as 100%, the content of 1,3-di(2-hydroxy-2-propyl)benzene is 0-2%, for example, 0%, 0.2%, 0.4%, 0.5%, 0.6%, 0.8%, 1%, 1.2%, 1.4%, 1.5%, 1.6%, 1.8%, 2%, etc.

[0116] Taking the total mass of the third liquid as 100%, the content of m-diisopropylbenzene hydroperoxide is 35-60%, for example, 35%, 36%, 38%, 40%, 42%, 44%, 45%, 46%, 48%, 50%, 52%, 54%, 55%, 56%, 58%, 60%, etc.

[0117] Taking the total mass of the third liquid as 100%, the content of the peroxidized polymer is 1-5%, for example, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, etc.

[0118] Taking the total mass of the third liquid feed as 100%, the content of other by-products is 2-9%, for example, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, etc.

[0119] As an optional embodiment, in step (b), the mass ratio of the third liquid to the neutralizing alkali solution is 1:(1-5), for example, it can be 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, etc.

[0120] As an optional embodiment, in step (b), the alkali solution is an aqueous solution of alkali with a solid content of 5 to 15 wt%; wherein the solid content of the alkali can be, for example, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 13wt%, 14wt%, 15wt% and the like.

[0121] As an optional embodiment, in step (b), the base is selected from any one or a combination of at least two of alkali metal hydroxides, alkali metal carbonates or alkali metal bicarbonates, preferably sodium hydroxide.

[0122] As an optional embodiment, in step (b), the fourth liquid comprises, by mass percentage, 10-30% of m-diisopropylbenzene dihydroperoxide, 0-1% of peroxide polymer and 65-75% of water.

[0123] Taking the total mass of the fourth liquid as 100%, the content of m-diisopropylbenzene dihydroperoxide is 10-30%, for example, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, etc.

[0124] Taking the total mass of the fourth liquid as 100%, the content of the peroxide polymer is 0-1%, for example, 0%, 0.2%, 0.4%, 0.5%, 0.6%, 0.8%, 1% and the like.

[0125] Taking the total mass of the fourth liquid as 100%, the water content therein is 65-75%, for example, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, etc.

[0126] As an optional embodiment, in step (b), the fifth feed liquid comprises, by mass percentage, 80-90% of m-diisopropylbenzene, 0-2% of 1,3-di(2-hydroxy-2-propyl)benzene, 1-5% of peroxide polymer and 5-13% of other by-products.

[0127] Taking the total mass of the fifth liquid as 100%, the content of m-diisopropylbenzene therein is 80-90%, for example, 80%, 82%, 84%, 85%, 86%, 88%, 90%, etc.

[0128] Taking the total mass of the fifth liquid as 100%, the content of 1,3-di(2-hydroxy-2-propyl)benzene is 0-2%, for example, 0%, 0.2%, 0.4%, 0.5%, 0.6%, 0.8%, 1%, 1.2%, 1.4%, 1.5%, 1.6%, 1.8%, 2%, etc.

[0129] Taking the total mass of the fifth liquid as 100%, the content of the peroxidized polymer is 1-5%, for example, 1%, 2%, 3%, 4%, 5%, etc.

[0130] Taking the total mass of the fifth liquid feed as 100%, the content of other by-products is 5-13%, for example, 5%, 6%, 8%, 10%, 12%, 13%, etc.

[0131] As an optional embodiment, in step (c), the secondary extraction further includes the steps of separation, peroxide removal, concentration and acid hydrolysis.

[0132] As an optional embodiment, in step (c), the specific steps of the secondary extraction are: extracting through a plate extraction tower, utilizing the characteristic that the solubility of m-diisopropylbenzene dihydroperoxide in organic solvents is greater than that in alkaline water, and extracting it into an organic solvent.

[0133] As an optional embodiment, in step (b), the fifth liquid obtained can be used as a raw material and circulated to the oxidation reaction step to undergo an oxidation reaction with oxygen to obtain a first liquid containing more than 65 wt % of m-diisopropylbenzene dihydroperoxide.

[0134] In a second aspect, the present invention provides an oxidation reaction device (such as Figure 1 As shown), the oxidation reaction device includes an oxidation reaction kettle body, a driving stirring device, an online viscosity detection device and an online pH detection device;

[0135] The driving and stirring device comprises a driving motor, a stirring motor and a stirring paddle, wherein the driving motor is fixedly mounted on the outer upper end of the oxidation reactor body, and the stirring paddle is connected to the stirring motor and is located inside the oxidation reactor body;

[0136] Wherein, the online viscosity detection device is connected to the driving stirring device and is used for online detection of the viscosity of the process system of the oxidation reaction of m-diisopropylbenzene and oxygen.

[0137] Studies have shown that the oxidation reaction is a free radical reaction, which will produce a variety of by-products (meta-diisopropylbenzene monohydroperoxide, 3-(2-hydroxy-2-propyl)isopropylbenzene hydroperoxide, 3-(2-hydroxy-2-propyl)isopropylbenzene, etc.). As the reaction proceeds, the by-products will continue to react to generate high molecular weight polymers (peroxidized polymers), forming high viscosity areas, reducing the fluidity of the reaction solution, reducing the local main reaction rate, increasing side reactions, and affecting the reaction effect. The present invention provides an oxidation reaction device that detects the pH and viscosity of the reaction solution online through the arrangement of an online viscosity detection device and an online pH detection device, thereby achieving regulation of the oxidation reaction, thereby effectively avoiding excessive decomposition of meta-diisopropylbenzene hydroperoxide produced by the reaction due to excessive acidity or alkalinity, and at the same time controlling the stirring by the driving stirring device to disperse the high viscosity components, reducing the problem of poor fluidity of the materials in the reaction device due to the aggregation of high viscosity components in the materials, and can bring better economic benefits and production benefits.

[0138] As an optional embodiment, a guide plate (such as Figure 3 As shown), and a heat exchange coil is arranged on the inner side of the guide plate for heat exchange.

[0139] As an optional embodiment, the width of the guide plate is 50% to 80% of the inner diameter of the oxidation reactor, for example, it can be 50%, 55%, 60%, 65%, 70%, 75%, 80%, etc.

[0140] As an optional embodiment, the oxidation reactor body further includes a feed port, and the feed port is located on one side of the upper portion of the oxidation reactor body, and is used to transport alkali solution and / or m-diisopropylbenzene into the interior of the oxidation reactor body.

[0141] As an optional embodiment, a transverse pipe is arranged above the interior of the oxidation reactor body, and one end of the transverse pipe is connected to the feed port of the oxidation reactor body, and four feed ports are arranged below the transverse pipe for transporting alkali solution and / or meta-diisopropylbenzene to the interior of the oxidation reactor body.

[0142] As an optional embodiment, among the four feed ports, the middle two feed ports are located to input alkali solution and / or m-diisopropylbenzene back-jacket liquid into the reaction zone inside the guide plate; the outer two feed ports transport the self-circulating liquid after heat exchange to the circulation zone outside the guide plate to provide a circulation effect.

[0143] As an optional embodiment, the oxidation reactor body further includes a product port, and the product port is located at the other side of the lower portion of the oxidation reactor body, and is used to transport the first feed liquid containing m-diisopropylbenzene dihydroperoxide to the outside.

[0144] As an optional embodiment, the oxidation reactor body further includes an air inlet, and the air inlet is located below the oxidation reactor body, and the air inlet is used to transport oxygen-containing gas, preferably air, into the interior of the oxidation reactor body.

[0145] As an optional implementation, the gas inlet is fixedly connected to a gas distribution device.

[0146] As an optional implementation, Figure 4 As shown, the gas distribution device is an annular gas distribution device, and the gas distribution device includes an annular body of the distribution device, an air inlet pipe, a distribution pipe and at least one air hole arranged on the annular body.

[0147] In the present invention, the gas distribution device is an annular gas distribution device, a plurality of rows of distribution holes are arranged on the annular device, and a stirring device is arranged directly above the annular distribution device.

[0148] As an optional embodiment, the oxidation reactor body further includes a tail gas outlet, and the tail gas outlet is arranged on one side of the top of the oxidation reactor body.

[0149] As an optional embodiment, there are at least 6 online viscosity detection points inside the oxidation reactor body, that is, 2 are set in the upper, middle and lower parts of the oxidation reactor body respectively; high-viscosity substances such as benzyl alcohol and peroxide polymers will be produced in the oxidation reaction system, resulting in increased viscosity; therefore, when the viscosity value of more than two detection points is greater than 10mPa·s, there may be local fluidity reduction in the reaction device, the material cannot flow well, and the reaction selectivity is reduced. At this time, the stirring is controlled to enhance the flow effect of the oxidation liquid and reduce the generation of high-viscosity by-products in the reaction, thereby reducing the viscosity. In addition, if it is not controlled, the high-viscosity component increases, and when the viscosity exceeds 15mPa·s, it will not only affect the reaction selectivity, but also reduce the conveying effect of the oxidation discharge pump, affecting the head, conveying flow rate, etc.

[0150] As an optional embodiment, the specific process of preparing the first feed liquid containing meta-diisopropylbenzene dihydroperoxide using the oxidation reaction device of the present invention includes: adding the reaction raw materials to the top feed port of the oxidation reaction device, and introducing nitrogen into the oxidation reaction device to pressurize to 200-600kPa; opening the alkali solution feed valve, adding dilute alkali solution to the oxidation reaction device to adjust the pH of the reaction solution to 9-11; opening the hot water feed valve, and introducing hot water into the heat exchange device to heat the reaction; when the temperature rises to the reaction temperature, opening the oxygen-containing gas inlet valve, and starting to introduce oxygen-containing gas into the oxidation reaction device, while reducing the nitrogen intake; after a certain reaction time, ensuring that the reaction is stable, opening the discharge valve, and starting continuous feeding and discharging. After the reaction is running normally, the system control is connected, and when the online device detects abnormal pH or viscosity, the corresponding parameters are controlled and adjusted.

[0151] In a third aspect, the present invention provides a production system of m-diisopropylbenzene dihydroperoxide (such as Figure 2 As shown), the production system of m-diisopropylbenzene dihydroperoxide includes a raw material feeding unit, the oxidation reaction device described in the second aspect, and a separation system.

[0152] As an optional embodiment, the feeding unit includes a diisopropylbenzene feeding unit, an alkali solution feeding unit and an oxygen-containing gas feeding unit.

[0153] As an optional embodiment, the m-diisopropylbenzene feeding unit includes a m-diisopropylbenzene recycling tank and a conveying pipeline, and the m-diisopropylbenzene conveying pipeline is connected to the feed port of the oxidation reaction device; the alkali solution feeding unit includes an alkali solution raw material tank and a conveying pipeline, and the alkali solution conveying pipeline is connected to the feed port of the oxidation reaction device; the oxygen-containing gas feeding unit includes an oxygen-containing gas storage tank and a conveying pipeline, and the oxygen-containing gas conveying pipeline is connected to the air inlet of the oxidation reaction device.

[0154] As an optional implementation, the product outlet of the oxidation reaction device is connected to the separation system via a pipeline, and the first feed liquid containing m-diisopropylbenzene dihydroperoxide is transported to the separation system.

[0155] As an optional embodiment, the separation system includes any one of an extraction device, a filtration device, an adsorption device, a distillation device or a crystallization device.

[0156] The present invention is further described below by way of examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or directly purchased from the market.

[0157] Example 1

[0158] The present embodiment provides a method for preparing m-diisopropylbenzene dihydroperoxide, and the method for preparing m-diisopropylbenzene dihydroperoxide comprises the following steps:

[0159] (1) 90% (mass ratio) of m-diisopropylbenzene (purity 98 wt%) is introduced into an oxidation reactor, and 5% (mass ratio) of alkali solution (concentration 1 wt%) is gradually and slowly introduced, and air is introduced into the oxidation reactor. The reaction temperature is set to 85° C., and the reaction pressure is 500 kPa. Within 3 hours of the reaction, 5% (mass ratio) of m-diisopropylbenzene hydroperoxide (initiator for the first batch of reactions) is added. After the reaction operation is stable, the residence time is controlled at 15 hours, and the tail oxygen content is controlled at 7%. After the reaction is normal and stable, continuous operation is started, and the fifth feed liquid after the alkali solution extraction is returned to the oxidation reaction;

[0160] Wherein, the oxidation reaction further includes the following separation steps:

[0161] (a) adding m-diisopropylbenzene to the first feed liquid in a mass ratio of 1:1 to separate the first feed liquid and obtain a second feed liquid and a third feed liquid;

[0162] Among them, the second feed liquid includes, by mass percentage, 5.12% of organic acid salt and 3.40% of peroxide polymer; the third feed liquid includes, by mass percentage, 53.39% of m-diisopropylbenzene, 38.16% of m-diisopropylbenzene hydroperoxide, 0.64% of 3-(2-hydroxy-2-propyl)isopropylbenzene, 1.70% of peroxide polymer and 6.11% of other components.

[0163] (b) adding an aqueous solution of sodium hydroxide (concentration 12 wt %) to the third feed liquid at a mass ratio of 3.8:1 to perform a first extraction to obtain a fourth feed liquid and a fifth feed liquid;

[0164] The fourth liquid comprises, by mass percentage, 16.65% of m-diisopropylbenzene dihydroperoxide and 0.22% of peroxide polymer; the fifth liquid comprises, by mass percentage, 86.33% of m-diisopropylbenzene, 1.04% of 1,3-di(2-hydroxy-2-propyl)benzene, 2.74% of peroxide polymer and 9.89% of other components;

[0165] The obtained fifth liquid can be used as a raw material and circulated to the oxidation reaction step to undergo an oxidation reaction with oxygen;

[0166] (c) transporting the fourth feed liquid to an extraction tower for secondary extraction to obtain alkali-free meta-diisopropylbenzene hydroperoxide.

[0167] (2) Online detection: The pH of the oxidation reaction solution is tested online through the pH detection system of the oxidation reactor, and the opening size of the alkali solution feed regulating valve is controlled online to keep the pH value of the reaction system at 10; the stirring motor of the agitator is controlled online through the online viscometer in the oxidation reactor. When the viscosity of the reaction solution is greater than 10 mPa·s, the stirring speed is controlled at 150 rpm, and when the viscosity of the reaction system is ≤5 mPa·s, the stirring is turned off.

[0168] After running for 800 hours according to the above process, the average viscosity of the reaction liquid (first feed liquid) was 5 mPa·s, the DHP selectivity was 95.76%, the content of m-diisopropylbenzene was 5.82%, the content of 1,3-di(2-hydroxy-2-propyl)benzene was 1.29%, the content of peroxide polymer was 3.43%, and the total content of other components was 12.36%.

[0169] Example 2

[0170] The present embodiment provides a method for preparing m-diisopropylbenzene dihydroperoxide, and the method for preparing m-diisopropylbenzene dihydroperoxide comprises the following steps:

[0171] (1) 90% (mass ratio) of m-diisopropylbenzene (purity 98 wt%) is introduced into an oxidation reactor, and 5% (mass ratio) of alkali solution (concentration 1 wt%) is gradually and slowly introduced, and 5% (mass ratio) of m-diisopropylbenzene hydroperoxide is added within 3 hours of reaction, and air is introduced into the oxidation reactor. The reaction temperature is set to 85° C. and the reaction pressure is 500 kPa. After the reaction operation is stable, the residence time is controlled to 15 hours, and the tail oxygen content is controlled to 7%. After the reaction is normal and stable, continuous operation is started, and the fifth feed liquid after sodium hydroxide extraction is returned to the oxidation reaction;

[0172] Wherein, the oxidation reaction further includes the following separation steps:

[0173] (a) adding m-diisopropylbenzene to the first feed liquid in a mass ratio of 1:1 to separate the first feed liquid and obtain a second feed liquid and a third feed liquid;

[0174] Among them, the second feed liquid includes, by mass percentage, 5.01% of organic acid salt and 3.22% of peroxide polymer; the third feed liquid includes, by mass percentage, 52.99% of m-diisopropylbenzene, 38.77% of m-diisopropylbenzene hydroperoxide, 0.57% of 3-(2-hydroxy-2-propyl)isopropylbenzene, 1.63% of peroxide polymer and 6.04% of other components.

[0175] (b) adding an aqueous solution of sodium hydroxide (concentration 12 wt %) to the third feed liquid at a mass ratio of 3.8:1 to perform a first extraction to obtain a fourth feed liquid and a fifth feed liquid;

[0176] The fourth liquid comprises, by mass percentage, 16.21% of m-diisopropylbenzene dihydroperoxide and 0.21% of peroxide polymer; the fifth liquid comprises, by mass percentage, 86.56% of m-diisopropylbenzene, 0.93% of 1,3-di(2-hydroxy-2-propyl)benzene, 2.66% of peroxide polymer and 9.85% of other components;

[0177] The obtained fifth liquid can be used as a raw material and circulated to the oxidation reaction step to undergo an oxidation reaction with oxygen;

[0178] (c) transporting the fourth feed liquid to an extraction tower for secondary extraction to obtain alkali-free meta-diisopropylbenzene hydroperoxide.

[0179] (2) Online detection: The pH of the oxidation reaction solution is tested online through the pH detection system of the oxidation reactor, and the opening size of the alkali solution feed regulating valve is controlled online to keep the pH value of the reaction system at 10; the stirring motor of the agitator is controlled online through the online viscometer in the oxidation reactor. When the viscosity of the reaction solution is greater than 10 mPa·s, the stirring speed is controlled at 100 rpm, and when the viscosity of the reaction system is ≤5 mPa·s, the stirring is turned off.

[0180] After running for 800 hours according to the above process, the average viscosity of the reaction liquid (first feed liquid) was 6 mPa·s, the selectivity was 96.09%, the content of m-diisopropylbenzene was 5.03%, the content of 1,3-di(2-hydroxy-2-propyl)benzene was 1.15%, the content of peroxide polymer was 3.29%, and the content of other substances was 12.19%.

[0181] Example 3

[0182] The present embodiment provides a method for preparing m-diisopropylbenzene dihydroperoxide, and the method for preparing m-diisopropylbenzene dihydroperoxide comprises the following steps:

[0183] (1) 90% (mass ratio) of m-diisopropylbenzene (purity 98 wt%) is introduced into an oxidation reactor, and 5% (mass ratio) of alkali solution (concentration 1 wt%) is gradually and slowly introduced, and 5% (mass ratio) of m-diisopropylbenzene hydroperoxide is added within 3 hours of reaction, and air is introduced into the oxidation reactor. The reaction temperature is set to 85° C. and the reaction pressure is 500 kPa. After the reaction operation is stable, the residence time is controlled to 15 hours, and the tail oxygen content is controlled to 7%. After the reaction is normal and stable, continuous operation is started, and the fifth feed liquid after sodium hydroxide extraction is returned to the oxidation reaction;

[0184] Wherein, the oxidation reaction further includes the following separation steps:

[0185] (a) adding m-diisopropylbenzene to the first feed liquid in a mass ratio of 1:1 to separate the first feed liquid and obtain a second feed liquid and a third feed liquid;

[0186] Among them, the second feed liquid includes, by mass percentage, 5.51% of organic acid salt and 3.66% of peroxide polymer; the third feed liquid includes, by mass percentage, 53.18% of m-diisopropylbenzene, 37.76% of m-diisopropylbenzene hydroperoxide, 0.61% of 3-(2-hydroxy-2-propyl)isopropylbenzene, 2.03% of peroxide polymer and 6.42% of other components.

[0187] (b) adding an aqueous solution of sodium hydroxide (concentration 12 wt %) to the third feed liquid at a mass ratio of 3.8:1 to perform a first extraction to obtain a fourth feed liquid and a fifth feed liquid;

[0188] The fourth liquid comprises, by mass percentage, 15.88% of m-diisopropylbenzene dihydroperoxide and 0.27% of peroxide polymer; the fifth liquid comprises, by mass percentage, 85.45% of m-diisopropylbenzene, 0.98% of 1,3-di(2-hydroxy-2-propyl)benzene, 3.26% of peroxide polymer and 10.31% of other components;

[0189] The obtained fifth liquid can be used as a raw material and circulated to the oxidation reaction step to undergo an oxidation reaction with oxygen;

[0190] (c) transporting the fourth feed liquid to an extraction tower for secondary extraction to obtain alkali-free meta-diisopropylbenzene hydroperoxide.

[0191] (2) Online detection: The pH of the oxidation reaction solution is tested online through the pH detection system of the oxidation reactor, and the opening size of the alkali solution feed regulating valve is controlled online to keep the pH value of the reaction system at 10; the stirring motor of the agitator is controlled online through the online viscometer in the oxidation reactor. When the viscosity of the reaction solution is greater than 10 mPa·s, the stirring speed is controlled at 50 rpm, and when the viscosity of the reaction system is ≤5 mPa·s, the stirring is turned off.

[0192] After running for 800 hours according to the above process, the average viscosity of the reaction liquid (first feed liquid) was 7 mPa·s, the selectivity was 95.32%, the content of m-diisopropylbenzene was 5.41%, the content of 1,3-di(2-hydroxy-2-propyl)benzene was 1.23%, the content of peroxide polymer was 4.1%, and the content of other substances was 12.96%.

[0193] Comparative Example 1

[0194] This comparative example provides a method for preparing m-diisopropylbenzene dihydroperoxide, which differs from Example 1 only in that:

[0195] Online detection: The pH of the oxidation reaction solution is tested online through the pH detection system of the oxidation reactor, and the opening size of the alkali solution feed regulating valve is controlled online to keep the pH value of the reaction system at 10; no online viscosity and agitator control is set, and the stirring speed is continuously controlled at 50 rpm during the reaction. The other steps are exactly the same as in Example 1.

[0196] After running for 800 hours according to the above process, the average viscosity of the reaction liquid was 6 mPa·s, the selectivity was 89.44%, the content of m-diisopropylbenzene was 5.56%, the content of 1,3-di(2-hydroxy-2-propyl)benzene was 2.85%, the content of peroxide polymer was 3.26%, and the content of others was 22.81%.

[0197] Comparative Example 2

[0198] This comparative example provides a method for preparing m-diisopropylbenzene dihydroperoxide, which differs from Example 1 only in that:

[0199] Online detection: The pH of the oxidation reaction solution is tested online through the pH detection system of the oxidation reactor, and the opening size of the alkali solution feed regulating valve is controlled online to keep the pH value of the reaction system at 10; no online viscosity and agitator control is set, and the stirring speed is continuously controlled at 150 rpm during the reaction. The other steps are exactly the same as in Example 1.

[0200] After running for 800 hours according to the above process, the average viscosity of the reaction liquid was 4 mPa·s, the selectivity was 88.10%, the content of m-diisopropylbenzene was 5.49%, the content of 1,3-di(2-hydroxy-2-propyl)benzene was 3.05%, the content of peroxide polymer was 3.31%, and the content of others was 24.56%.

[0201] Comparative Example 3

[0202] This comparative example provides a method for preparing m-diisopropylbenzene dihydroperoxide, which differs from Example 1 only in that:

[0203] Online detection: The pH of the oxidation reaction solution is tested online through the pH detection system of the oxidation reactor, and the opening size of the alkali solution feed regulating valve is controlled online so that the pH value of the reaction system is maintained at 10; no online viscosity and agitator control is set, and the other steps are completely consistent with Example 1.

[0204] After running for 800 hours according to the above process, the selectivity was 80.12%, the content of m-diisopropylbenzene was 17.16%, the content of 1,3-di(2-hydroxy-2-propyl)benzene was 5.19%, the content of peroxide polymer was 17.4%, and the content of others was 11.83%.

[0205] Comparative Example 4

[0206] This comparative example provides a method for preparing m-diisopropylbenzene dihydroperoxide, which is different from Example 1 only in that no pH control is provided, and no online viscosity and stirrer control is provided, and other steps are completely consistent with Example 1.

[0207] After running for 800 hours according to the above process, the selectivity is 76.40%, the content of m-diisopropylbenzene is 15.45%, the content of 1,3-di(2-hydroxy-2-propyl)benzene is 2.64%, the content of peroxide polymer is 15.37%, and the content of others is 20.98%.

[0208] 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 m-diisopropylbenzene dihydroperoxide, characterized in that: The preparation method of the m-diisopropylbenzene dihydroperoxide comprises the following steps: In the presence of an alkali solution, m-diisopropylbenzene is oxidized with oxygen to obtain a first feed liquid containing m-diisopropylbenzene dihydroperoxide with a content of more than 50 wt %; Wherein, during the oxidation reaction, the pH of the reaction system is controlled to be 9-11, and the viscosity of the reaction system is controlled to be less than 10 mPa·s.

2. The method for preparing m-diisopropylbenzene dihydroperoxide according to claim 1, characterized in that: The first feed liquid also includes: m-diisopropylbenzene, 1,3-di(2-hydroxy-2-propyl)benzene, peroxide polymers and other by-products; Preferably, the other by-products are selected from any one or a combination of at least two of m-diisopropylbenzene monohydroperoxide, 3-(2-hydroxy-2-propyl)isopropylbenzene hydroperoxide or 3-(2-hydroxy-2-propyl)isopropylbenzene; Preferably, the first liquid comprises, by mass percentage, 65-80% of m-diisopropylbenzene hydroperoxide, 3-10% of m-diisopropylbenzene, 0-2% of 1,3-di(2-hydroxy-2-propyl)benzene, 3-8% of peroxide polymer and 10-18% of other by-products.

3. The method for preparing m-diisopropylbenzene dihydroperoxide according to claim 1, characterized in that: During the oxidation reaction, the reaction system is controlled by controlling the feed amount of the alkali solution; Preferably, the mass ratio of the alkali solution to m-diisopropylbenzene is (0.05-0.5):1; Preferably, the alkali solution is an aqueous solution of alkali with a solid content of 0 to 5 wt%; Preferably, the base is selected from any one or a combination of at least two of alkali metal hydroxides, alkali metal carbonates or alkali metal bicarbonates, preferably any one or a combination of at least two of sodium hydroxide, sodium bicarbonate, sodium carbonate, potassium hydroxide, potassium carbonate or potassium bicarbonate.

4. The method for preparing m-diisopropylbenzene dihydroperoxide according to claim 1, characterized in that: During the oxidation reaction, the viscosity of the reaction system is controlled by controlling the stirring speed; Preferably, the stirring speed is 50-150 rpm.

5. The method for preparing m-diisopropylbenzene dihydroperoxide according to claim 1, characterized in that: The pressure of the oxidation reaction is 200-600 kPa; Preferably, the temperature of the oxidation reaction is 70 to 90°C; Preferably, the residence time of the oxidation reaction is 10 to 20 hours.

6. The method for preparing m-diisopropylbenzene dihydroperoxide according to claim 1, characterized in that: The preparation method also includes the following separation steps: (a) adding m-diisopropylbenzene to the first feed liquid to separate and obtain a second feed liquid and a third feed liquid; Wherein, the second feed liquid includes: organic acid salt and peroxide polymer; the third feed liquid includes: m-diisopropylbenzene, 1,3-di(2-hydroxy-2-propyl)benzene, peroxide polymer and other by-products; (b) adding alkali solution to the third feed liquid to perform a first extraction to obtain a fourth feed liquid and a fifth feed liquid; The fourth liquid includes: m-diisopropylbenzene dihydroperoxide, peroxide polymer, water and other by-products; the fifth liquid includes: m-diisopropylbenzene, 1,3-di(2-hydroxy-2-propyl)benzene peroxide polymer and other by-products; (c) transporting the fourth feed liquid to an extraction tower for secondary extraction to separate the m-diisopropylbenzene dihydroperoxide from the alkali solution.

7. The method for preparing m-diisopropylbenzene dihydroperoxide according to claim 6, characterized in that: In step (a), the mass ratio of the first feed liquid to m-diisopropylbenzene is 1:(0.5-5); Preferably, in step (a), the second liquid comprises, by mass percentage, 1 to 10% of an organic acid salt and 1 to 10% of a peroxidized polymer; Preferably, in step (a), the organic acid salt comprises any one or a combination of at least two of sodium phenolate, sodium formate, sodium acetate or sodium propionate; Preferably, in step (a), the third liquid comprises, by mass percentage, 40-55% of m-diisopropylbenzene, 0-2% of 1,3-di(2-hydroxy-2-propyl)benzene, 35-60% of m-diisopropylbenzene dihydroperoxide, 1-5% of peroxide polymer, and 2-9% of other by-products; Preferably, in step (b), the mass ratio of the third liquid to the neutralizing alkali solution is 1:(1-5); Preferably, in step (b), the alkali solution is an aqueous solution of alkali having a solid content of 5 to 15 wt%; Preferably, in step (b), the base is selected from any one or a combination of at least two of alkali metal hydroxides, alkali metal carbonates or alkali metal bicarbonates, preferably sodium hydroxide; Preferably, in step (b), the fourth liquid comprises, by mass percentage, 10-30% of m-diisopropylbenzene dihydroperoxide, 0-1% of peroxide polymer and 65-75% of water; Preferably, in step (b), the fifth liquid comprises, by mass percentage, 80-90% of m-diisopropylbenzene, 0-2% of 1,3-di(2-hydroxy-2-propyl)benzene, 1-5% of peroxide polymer, and 5-13% of other by-products; Preferably, in step (b), the fifth liquid obtained can be used as a raw material and circulated to the oxidation reaction step to undergo an oxidation reaction with oxygen to obtain a first liquid containing more than 65 wt % of m-diisopropylbenzene dihydroperoxide.

8. An oxidation reaction device, characterized in that: The oxidation reaction device comprises an oxidation reaction kettle body, a driving stirring device, an online viscosity detection device and an online pH detection device; The driving and stirring device comprises a driving motor, a stirring motor and a stirring paddle, wherein the driving motor is fixedly mounted on the outer upper end of the oxidation reactor body, and the stirring paddle is connected to the stirring motor and is located inside the oxidation reactor body; Wherein, the online viscosity detection device is connected to the driving stirring device and is used for online detection of the viscosity of the process system of the oxidation reaction of m-diisopropylbenzene and oxygen.

9. The oxidation reaction device according to claim 8, characterized in that: A guide plate is arranged inside the oxidation reactor body, and a heat exchange coil is arranged inside the guide plate for heat exchange; Preferably, the width of the guide plate is 50-80% of the inner diameter of the oxidation reactor; Preferably, the oxidation reactor body further comprises a feed port, and the feed port is located on one side of the upper part of the oxidation reactor body, and is used to transport alkali solution and / or meta-diisopropylbenzene into the interior of the oxidation reactor body; Preferably, a transverse pipe is arranged above the inside of the oxidation reactor body, and one end of the transverse pipe is connected to the feed port of the oxidation reactor body, and four feed ports are arranged below the transverse pipe for conveying alkali solution and / or meta-diisopropylbenzene into the inside of the oxidation reactor body; Among the four feed ports, the middle two feed ports are located to input alkali solution and / or m-diisopropylbenzene jacket liquid into the reaction zone inside the guide plate; the outer two feed ports transport the self-circulating liquid after heat exchange to the circulation zone outside the guide plate to provide a circulation effect; Preferably, the oxidation reactor body further comprises a product port, and the product port is located at the other side of the lower part of the oxidation reactor body, and is used to transport the first feed liquid containing m-diisopropylbenzene dihydroperoxide to the outside; Preferably, the oxidation reactor body further comprises an air inlet, and the air inlet is located below the oxidation reactor body, and the air inlet is used to transport oxygen-containing gas, preferably air, into the interior of the oxidation reactor body; Preferably, the air inlet is fixedly connected with a gas distribution device; Wherein, the gas distribution device is an annular gas distribution device, and the gas distribution device comprises an annular body of the distribution device, an air inlet pipe, a distribution pipe and at least one air hole arranged on the annular body; Preferably, the oxidation reactor body further includes a tail gas outlet, and the tail gas outlet is arranged on one side of the top of the oxidation reactor body.

10. A system for producing m-diisopropylbenzene dihydroperoxide, characterized in that: The m-diisopropylbenzene dihydroperoxide production system comprises a raw material feeding unit, an oxidation reaction device according to claim 8 or 9, and a separation system; And / or, the feed unit comprises a diisopropylbenzene feed unit, an alkali solution feed unit and an oxygen-containing gas feed unit; Wherein, the m-diisopropylbenzene feeding unit comprises a m-diisopropylbenzene recycle tank and a m-diisopropylbenzene delivery pipeline, and the m-diisopropylbenzene delivery pipeline is connected to the feed port of the oxidation reaction device; the alkali solution feeding unit comprises an alkali solution raw material tank and an alkali solution delivery pipeline, and the alkali solution delivery pipeline is connected to the feed port of the oxidation reaction device; the oxygen-containing gas feeding unit comprises an oxygen-containing gas storage tank and an oxygen-containing gas delivery pipeline, and the oxygen-containing gas delivery pipeline is connected to the gas inlet of the oxidation reaction device; And / or, the product outlet of the oxidation reaction device is connected to the separation system through a pipeline, and the first feed liquid containing m-diisopropylbenzene dihydroperoxide is transported to the separation system; Preferably, the separation system comprises any one of an extraction device, a filtration device, an adsorption device, a distillation device or a crystallization device.

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