Preparation method of diisopropylbenzene dihydroperoxide

Abstract

The invention relates to a preparation method of diisopropylbenzene dihydroperoxide, diisopropylbenzene is oxidized to prepare the diisopropylbenzene dihydroperoxide, preparation and separation of the diisopropylbenzene dihydroperoxide are realized through operation of three-stage oxidation reaction-alkali liquor extraction and separation, and the method is good in reaction safety, high in raw material utilization rate, few in side reaction and high in yield. The target product is high in yield and selectivity and excellent in industrial application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of organic compound synthesis, and particularly relates to a preparation method of diisopropylbenzene dihydroperoxide. Background Art

[0002] Diisopropylbenzene dihydroperoxide, a peroxide obtained by oxidizing diisopropylbenzene, can be used as a radical reaction initiator, an oxidant, an organic synthesis intermediate, etc., and is currently widely used in the industrial production of α,α'-dihydroxy-diisopropylbenzene, resorcinol, hydroquinone, etc.

[0003] Currently, the main preparation method of diisopropylbenzene dihydroperoxide is to prepare it by oxidizing diisopropylbenzene with an oxygen-containing gas in an alkaline environment. Taking m-diisopropylbenzene as an example, the reaction formula is as follows:

[0004]

[0005] Among them, DHP, MHP, and HHP are all the effective product diisopropylbenzene hydroperoxides.

[0006] Since the reaction products of this reaction are mostly peroxides and are unstable in nature, considering the reaction safety, the reaction conversion rate cannot be too high. To improve the raw material utilization rate, it is necessary to separate the target product DHP from the unreacted raw material m-DIPB and the intermediate product MHP. The unreacted raw material m-DIPB and the intermediate product MHP are recycled and reused, and after being mixed with the fresh m-DIPB raw material, they continue to react with the oxidant.

[0007] The oxidation of diisopropylbenzene to diisopropylbenzene dihydroperoxide is a typical radical reaction, and there are many types of by-products. The generated acidic by-products will inhibit the progress of the oxidation reaction. Usually, an alkali needs to be added to the reaction solution to neutralize the acidic substances, and the introduction of the alkali will catalyze the decomposition of MHP and DHP to generate by-products such as benzyl alcohol; as the reaction proceeds and the reaction depth deepens, the concentration of the dihydroperoxide DHP gradually increases. The dihydroperoxide DHP is unstable itself and will decompose when the concentration is high. At the same time, it will also continue to react with intermediate products, by-products, etc. to generate other by-products, resulting in poor reaction selectivity and low yield. The reaction formula is as follows:

[0008]

[0009] During the process of raw material recycling, it is easy to accumulate impurities, which seriously affects the reaction yield and causes unstable operation. Therefore, controlling the generation of by-products is a relatively key technical problem.

[0010] US 3953521 A discloses a process for continuously producing dihydroperoxide. In this process, meta - diisopropylbenzene and / or para - diisopropylbenzene dihydroperoxide are continuously produced by oxidizing meta - diisopropylbenzene and / or para - diisopropylbenzene in the liquid phase by contacting with oxygen or oxygen - containing gas, while maintaining the concentration of meta - diisopropylbenzene and / or para - diisopropylbenzene monohydroperoxide in the oxidation product solution within the range of 20 - 40% (by weight). The oil - phase raw material and the lye enter the reactor simultaneously, react with air. After stabilization, the concentration of MHP at the outlet is 34.5%, the concentration of DHP is 19.4%, and the concentration of DIPB is 17.9%. Therefore, the content of other by - product components exceeds 20%. The yield of DHP from diisopropylbenzene in the reaction solution is approximately 76.3% through calculation, and the yield is relatively low.

[0011] CN 113173874 A discloses a method for extracting hydroperoxide from the oxidation product of meta - diisopropylbenzene. The method successively performs lye extraction, neutralization, and back - extraction on the hydroperoxide intermediate DHP and by - products generated after the first oxidation of meta - diisopropylbenzene. Meanwhile, the influence of pH value on the effect of back - extracting DHP is explored, realizing the ability to precisely control the treatment of intermediate products, which is conducive to the subsequent secondary oxidation and a significant increase in the yield of resorcinol. When controlling the intermediate products in this method, the process is relatively complex, and the total peroxide content in the reaction solution still needs to be reduced.

[0012] In view of the deficiencies of the prior art, there is a need to provide a method for preparing diisopropylbenzene dihydroperoxide with good reaction safety, high raw material utilization rate, few side reactions, high target product yield, and low total peroxide content in the reaction solution. Summary of the Invention

[0013] The purpose of the present invention is to provide a method for preparing diisopropylbenzene dihydroperoxide. Diisopropylbenzene is oxidized to prepare diisopropylbenzene dihydroperoxide. Through a three - stage oxidation reaction - lye extraction and separation operation, the preparation and separation of the target product diisopropylbenzene dihydroperoxide are realized. This method has good reaction safety, high raw material utilization rate, few side reactions, and excellent industrial application prospects.

[0014] To achieve the purpose of this invention, the following technical solutions are adopted:

[0015] The present invention provides a method for preparing diisopropylbenzene dihydroperoxide, and the preparation method includes the following steps:

[0016] (1) After introducing an oxygen - containing gas into diisopropylbenzene, a first oxidation reaction is carried out to obtain a first reaction solution; the obtained first reaction solution is subjected to counter - current extraction with a lye to obtain a first oil phase and an aqueous phase;

[0017] (2) Oxygen-containing gas is introduced into the first oil phase obtained in step (1), and then a second oxidation reaction is carried out to obtain a second reaction solution; the obtained second reaction solution is subjected to countercurrent extraction with an alkali solution to obtain a second oil phase and an aqueous phase;

[0018] (3) Oxygen-containing gas is introduced into the second oil phase obtained in step (2), and then a third oxidation reaction is carried out to obtain a third reaction solution; the obtained third reaction solution is subjected to countercurrent extraction with an alkali solution to obtain a third oil phase and an aqueous phase;

[0019] (4) The third oil phase obtained in step (3) is recycled and used in the first oxidation reaction described in step (1); the aqueous phases obtained in step (1), step (2), and step (3) are combined to obtain the diisopropylbenzene dihydroperoxide.

[0020] The preparation method of diisopropylbenzene dihydroperoxide provided by the present invention divides the oxidation reaction of diisopropylbenzene into three stages, which can control the diisopropylbenzene dihydroperoxide in a single stage at a low concentration, avoid the large amount of by-products generated by deep reaction, and the disadvantages of the reduction of the yield caused by the side reaction of high-concentration diisopropylbenzene dihydroperoxide. At the same time, it can effectively reduce the total peroxide content in the reaction solution, significantly improve the reaction safety, reduce the possibility and severity of the out-of-control reaction; in addition, the acidic by-products generated in each stage can be neutralized by the alkali during the alkali solution extraction process and enter the aqueous phase, without affecting the progress of the oxidation reaction; at the same time, without adding an alkali solution to the reaction solution, it can also effectively reduce the generation of benzyl alcohol impurities caused by the decomposition of peroxides catalyzed by alkali during the high-temperature reaction process. The obtained diisopropylbenzene dihydroperoxide has a high yield, good selectivity and safety of the oxidation reaction, high raw material utilization rate, few side reactions, and excellent industrial application prospects.

[0021] Preferably, the diisopropylbenzene in step (1) includes 1,3-diisopropylbenzene and / or 1,4-diisopropylbenzene.

[0022] Preferably, the oxygen-containing gas in step (1), step (2), and step (3) independently includes air and / or oxygen.

[0023] Preferably, the temperature of the first oxidation reaction in step (1) is 70-150 °C, for example, it can be 70 °C, 85 °C, 100 °C, 110 °C or 150 °C, but not limited to the listed values, and other unlisted values within the numerical range are equally applicable, preferably 85-110 °C.

[0024] Preferably, the pressure of the first oxidation reaction in step (1) is 1-10 barg, for example, it can be 1 barg, 2 barg, 4 barg, 6 barg or 10 barg, but not limited to the listed values, and other unlisted values within the numerical range are equally applicable, preferably 2-6 barg.

[0025] Preferably, the time of the first oxidation reaction in step (1) is 2 - 20 h, for example, it can be 2 h, 3 h, 10 h, 15 h or 20 h, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable, preferably 3 - 15 h.

[0026] Preferably, the lye in step (1), step (2) and step (3) independently includes sodium hydroxide solution.

[0027] Preferably, the mass concentration of sodium hydroxide in the sodium hydroxide solution is 4 - 20 wt%, for example, it can be 4 wt%, 6 wt%, 9 wt%, 12 wt% or 20 wt%, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable, preferably 6 - 12 wt%.

[0028] Preferably, the temperature of the second oxidation reaction in step (2) is 70 - 150 °C, for example, it can be 70 °C, 85 °C, 100 °C, 110 °C or 150 °C, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable, preferably 85 - 110 °C.

[0029] Preferably, the pressure of the second oxidation reaction in step (2) is 1 - 10 barg, for example, it can be 1 barg, 2 barg, 4 barg, 6 barg or 10 barg, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable, preferably 2 - 6 barg.

[0030] Preferably, the time of the second oxidation reaction in step (2) is 2 - 20 h, for example, it can be 2 h, 3 h, 10 h, 15 h or 20 h, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable, preferably 3 - 15 h.

[0031] Preferably, the temperature of the third oxidation reaction in step (3) is 70 - 150 °C, for example, it can be 70 °C, 85 °C, 100 °C, 110 °C or 150 °C, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable, preferably 85 - 110 °C.

[0032] Preferably, the pressure of the third oxidation reaction in step (3) is 1 - 10 barg, for example, it can be 1 barg, 2 barg, 4 barg, 6 barg or 10 barg, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable, preferably 2 - 6 barg.

[0033] Preferably, the time of the third oxidation reaction in step (3) is 2 - 20 h, for example, it can be 2 h, 3 h, 10 h, 15 h or 20 h, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable, preferably 3 - 15 h.

[0034] Preferably, the oxidation reactors used in the first oxidation reaction in step (1), the second oxidation reaction in step (2), and the third oxidation reaction in step (3) independently include a bubble column or a stirred tank reactor respectively.

[0035] The ranges of temperature and pressure need to be limited in the first oxidation reaction, the second oxidation reaction, and the third oxidation reaction. If the reaction temperature and pressure are too low, the reaction rate will become slow, while if the reaction temperature is too high, side reactions will intensify and by-products will increase, and if the reaction pressure is too high, the equipment cost will increase.

[0036] It should be noted that three-stage oxidation reaction is set in the present invention, rather than one-stage or two-stage oxidation reaction. This is because if the number of stages is too small, the content of diisopropylbenzene in the reaction liquid will be high, and it is difficult to completely extract HHP and DHP into the lye in the lye extraction and separation step, resulting in the accumulation of HHP and DHP in the oil-phase reaction liquid, and then generating by-products, resulting in poor selectivity. Moreover, if the number of stages is too small, the single-pass product production amount will be small and the production efficiency will be low; four-stage oxidation reaction is not set either, because if the number of stages is too large, the number of extraction operations will increase, which will make the contact time between the oil-phase reaction liquid and the lye too long, resulting in the decomposition of intermediate products such as MHP. In addition, if the number of stages is too large, the operation process will become more complicated.

[0037] Preferably, the concentration of diisopropylbenzene dihydroperoxide in the first reaction liquid in step (1), the second reaction liquid in step (2), and the third reaction liquid in step (3) is controlled at 5 - 10%, for example, it can be 5%, 6%, 7%, 8% or 10%, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0038] Preferably, the specific steps of the recycling in step (4) include: the third oil phase is mixed with the diisopropylbenzene in step (1) and then oxygen-containing gas is introduced, and then the first oxidation reaction is continued.

[0039] As a preferred technical solution of the preparation method described in the present invention, the preparation method includes the following steps:

[0040] (1) After introducing air and / or oxygen into 1,3 - diisopropylbenzene and / or 1,4 - diisopropylbenzene, a first oxidation reaction is carried out in a bubble column or a stirred tank reactor at 70 - 150 °C and 1 - 10 barg for 2 - 20 h to obtain a first reaction solution with the concentration of diisopropylbenzene dihydroperoxide controlled at 5 - 10%; the obtained first reaction solution is subjected to countercurrent extraction with a sodium hydroxide solution having a mass concentration of 4 - 20 wt% of sodium hydroxide to obtain a first oil phase and an aqueous phase;

[0041] (2) After introducing air and / or oxygen into the first oil phase obtained in step (1), a second oxidation reaction is carried out in a bubble column or a stirred tank reactor at 70 - 150 °C and 1 - 10 barg for 2 - 20 h to obtain a second reaction solution with the concentration of diisopropylbenzene dihydroperoxide controlled at 5 - 10%; the obtained second reaction solution is subjected to countercurrent extraction with a sodium hydroxide solution having a mass concentration of 4 - 20 wt% of sodium hydroxide to obtain a second oil phase and an aqueous phase;

[0042] (3) After introducing air and / or oxygen into the second oil phase obtained in step (2), a third oxidation reaction is carried out in a bubble column or a stirred tank reactor at 70 - 150 °C and 1 - 10 barg for 2 - 20 h to obtain a third reaction solution with the concentration of diisopropylbenzene dihydroperoxide controlled at 5 - 10%; the obtained third reaction solution is subjected to countercurrent extraction with a sodium hydroxide solution having a mass concentration of 4 - 20 wt% of sodium hydroxide to obtain a third oil phase and an aqueous phase;

[0043] (4) The third oil phase obtained in step (3) is recycled and used in the first oxidation reaction described in step (1), and the specific steps of the recycling include: the third oil phase is mixed with 1,3 - diisopropylbenzene and / or 1,4 - diisopropylbenzene described in step (1) and then air and / or oxygen is introduced, and then the first oxidation reaction is continued; the aqueous phases obtained in step (1), step (2) and step (3) are combined to obtain the diisopropylbenzene dihydroperoxide.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] The preparation method of diisopropylbenzene dihydroperoxide provided by the present invention divides the oxidation reaction of diisopropylbenzene into three stages, which can control the diisopropylbenzene dihydroperoxide in a single stage at a low concentration, avoid a large amount of by-products generated by deep reaction, and the disadvantages of reduced yield caused by side reactions of high-concentration diisopropylbenzene dihydroperoxide. At the same time, it can effectively reduce the total peroxide content in the reaction solution, significantly improve the reaction safety, reduce the possibility and severity of out-of-control reactions; in addition, the acidic by-products generated in each stage can be neutralized by alkali during the alkali extraction process and enter the aqueous phase, without affecting the progress of the oxidation reaction; at the same time, without adding alkali solution to the reaction solution, it can also effectively reduce the generation of benzyl alcohol impurities caused by the decomposition of peroxides catalyzed by alkali during the high-temperature reaction process. The prepared diisopropylbenzene dihydroperoxide has a high yield, good selectivity and safety of the oxidation reaction, high raw material utilization rate, few side reactions, and excellent industrial application prospects. Specific Embodiments

[0046] The technical solution of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0047] The raw materials and reagents used in the examples and comparative examples of the present invention are all obtained from commercial sources through commercial channels, unless otherwise specified.

[0048] Product content testing method:

[0049] High performance liquid chromatography: Shimadzu LC-20AT, operating conditions: chromatographic column: Waters XSelect HSS T3 5μm×4.6mm×250mm, detection wavelength 233nm, mobile phase: acetonitrile / water (water contains 0.1% phosphoric acid) = 35 / 65, elution method: isocratic elution, flow rate: 1.0 mL / min, column temperature 30°C, injection volume 10 μL.

[0050] Example 1

[0051] This example provides a preparation method of diisopropylbenzene dihydroperoxide, and the preparation method includes the following steps:

[0052] (1) After introducing air into 1,3-diisopropylbenzene, carry out the first oxidation reaction in a stirred tank reactor at 100°C and 4 barg for 10 h to obtain a first reaction solution with the concentration of diisopropylbenzene dihydroperoxide controlled at 10%; the obtained first reaction solution is subjected to countercurrent extraction with a sodium hydroxide solution with a mass concentration of 9 wt% of sodium hydroxide to obtain a first oil phase and an aqueous phase;

[0053] (2) After introducing air into the first oil phase obtained in step (1), a second oxidation reaction is carried out in a stirred autoclave reactor at 100 °C and 4 barg for 10 h to obtain a second reaction solution with the concentration of diisopropylbenzene dihydroperoxide controlled at 10%; the obtained second reaction solution is subjected to countercurrent extraction with a sodium hydroxide solution with a mass concentration of 9 wt% of sodium hydroxide to obtain a second oil phase and an aqueous phase;

[0054] (3) After introducing air into the second oil phase obtained in step (2), a third oxidation reaction is carried out in a stirred autoclave reactor at 100 °C and 4 barg for 10 h to obtain a third reaction solution with the concentration of diisopropylbenzene dihydroperoxide controlled at 10%; the obtained third reaction solution is subjected to countercurrent extraction with a sodium hydroxide solution with a mass concentration of 9 wt% of sodium hydroxide to obtain a third oil phase and an aqueous phase;

[0055] (4) The third oil phase obtained in step (3) is recycled and used in the first oxidation reaction described in step (1), and the specific steps of the recycling include: the third oil phase is mixed with 1,3 - diisopropylbenzene described in step (1), air is introduced, and then the first oxidation reaction is continued; the aqueous phases obtained in step (1), step (2), and step (3) are combined to obtain the diisopropylbenzene dihydroperoxide.

[0056] Example 2

[0057] This example provides a preparation method of diisopropylbenzene dihydroperoxide, and the preparation method includes the following steps:

[0058] (1) After introducing air into 1,3 - diisopropylbenzene, a first oxidation reaction is carried out in a bubble column at 85 °C and 2 barg for 15 h to obtain a first reaction solution with the concentration of diisopropylbenzene dihydroperoxide controlled at 7%; the obtained first reaction solution is subjected to countercurrent extraction with a sodium hydroxide solution with a mass concentration of 6 wt% of sodium hydroxide to obtain a first oil phase and an aqueous phase;

[0059] (2) After introducing air into the first oil phase obtained in step (1), a first oxidation reaction is carried out in a bubble column at 85 °C and 2 barg for 15 h to obtain a second reaction solution with the concentration of diisopropylbenzene dihydroperoxide controlled at 7%; the obtained second reaction solution is subjected to countercurrent extraction with a sodium hydroxide solution with a mass concentration of 6 wt% of sodium hydroxide to obtain a second oil phase and an aqueous phase;

[0060] (3) After introducing air into the second oil phase obtained in step (2), a first oxidation reaction is carried out in a bubble column at 85 °C and 2 barg for 15 h to obtain a third reaction solution with the concentration of diisopropylbenzene dihydroperoxide controlled at 7%; the obtained third reaction solution is subjected to countercurrent extraction with a sodium hydroxide solution with a mass concentration of 6 wt% of sodium hydroxide to obtain a third oil phase and an aqueous phase;

[0061] (4) The third oil phase obtained in step (3) is recycled to the first oxidation reaction described in step (1). The specific steps of the recycling include: the third oil phase is mixed with 1,3 - diisopropylbenzene in step (1), and then air is introduced, followed by continuing the first oxidation reaction; the aqueous phases obtained in step (1), step (2), and step (3) are combined to obtain the diisopropylbenzene dihydroperoxide.

[0062] Example 3

[0063] This example provides a method for preparing diisopropylbenzene dihydroperoxide. The preparation method includes the following steps:

[0064] (1) After introducing air into 1,3 - diisopropylbenzene, a first oxidation reaction is carried out in a stirred autoclave reactor at 110 °C and 6 barg for 3 h to obtain a first reaction solution with the concentration of diisopropylbenzene dihydroperoxide controlled at 8%; the obtained first reaction solution is subjected to counter - current extraction with a sodium hydroxide solution having a mass concentration of 12 wt% of sodium hydroxide to obtain a first oil phase and an aqueous phase;

[0065] (2) After introducing air into the first oil phase obtained in step (1), a first oxidation reaction is carried out in a stirred autoclave reactor at 110 °C and 6 barg for 3 h to obtain a second reaction solution with the concentration of diisopropylbenzene dihydroperoxide controlled at 8%; the obtained second reaction solution is subjected to counter - current extraction with a sodium hydroxide solution having a mass concentration of 12 wt% of sodium hydroxide to obtain a second oil phase and an aqueous phase;

[0066] (3) After introducing air into the second oil phase obtained in step (2), a first oxidation reaction is carried out in a stirred autoclave reactor at 110 °C and 6 barg for 3 h to obtain a third reaction solution with the concentration of diisopropylbenzene dihydroperoxide controlled at 8%; the obtained third reaction solution is subjected to counter - current extraction with a sodium hydroxide solution having a mass concentration of 12 wt% of sodium hydroxide to obtain a third oil phase and an aqueous phase;

[0067] (4) The third oil phase obtained in step (3) is recycled to the first oxidation reaction described in step (1). The specific steps of the recycling include: the third oil phase is mixed with 1,3 - diisopropylbenzene in step (1), and then air is introduced, followed by continuing the first oxidation reaction; the aqueous phases obtained in step (1), step (2), and step (3) are combined to obtain the diisopropylbenzene dihydroperoxide.

[0068] Example 4

[0069] This example provides a method for preparing diisopropylbenzene dihydroperoxide. The preparation method includes the following steps:

[0070] (1) After introducing air into 1,3 - diisopropylbenzene, a first oxidation reaction is carried out in a stirred tank reactor at 70 °C and 10 barg for 20 h to obtain a first reaction solution with the concentration of diisopropylbenzene dihydroperoxide controlled at 5%; the obtained first reaction solution is subjected to countercurrent extraction with a sodium hydroxide solution having a mass concentration of 4 wt% of sodium hydroxide to obtain a first oil phase and an aqueous phase;

[0071] (2) After introducing air into the first oil phase obtained in step (1), a first oxidation reaction is carried out in a stirred tank reactor at 70 °C and 10 barg for 20 h to obtain a second reaction solution with the concentration of diisopropylbenzene dihydroperoxide controlled at 5%; the obtained second reaction solution is subjected to countercurrent extraction with a sodium hydroxide solution having a mass concentration of 4 wt% of sodium hydroxide to obtain a second oil phase and an aqueous phase;

[0072] (3) After introducing air into the second oil phase obtained in step (2), a first oxidation reaction is carried out in a stirred tank reactor at 70 °C and 10 barg for 20 h to obtain a third reaction solution with the concentration of diisopropylbenzene dihydroperoxide controlled at 5%; the obtained third reaction solution is subjected to countercurrent extraction with a sodium hydroxide solution having a mass concentration of 4 wt% of sodium hydroxide to obtain a third oil phase and an aqueous phase;

[0073] (4) The third oil phase obtained in step (3) is recycled to the first oxidation reaction described in step (1), and the specific steps of the recycling include: the third oil phase is mixed with 1,3 - diisopropylbenzene described in step (1), air is introduced, and then the first oxidation reaction is continued; the aqueous phases obtained in step (1), step (2), and step (3) are combined to obtain the diisopropylbenzene dihydroperoxide.

[0074] Example 5

[0075] This example provides a method for preparing diisopropylbenzene dihydroperoxide, and the preparation method includes the following steps:

[0076] (1) After introducing air into 1,3 - diisopropylbenzene, a first oxidation reaction is carried out in a stirred tank reactor at 150 °C and 1 barg for 2 h to obtain a first reaction solution with the concentration of diisopropylbenzene dihydroperoxide controlled at 6%; the obtained first reaction solution is subjected to countercurrent extraction with a sodium hydroxide solution having a mass concentration of 20 wt% of sodium hydroxide to obtain a first oil phase and an aqueous phase;

[0077] (2) After introducing air into the first oil phase obtained in step (1), a first oxidation reaction is carried out in a stirred tank reactor at 150 °C and 1 barg for 2 h to obtain a second reaction solution with the concentration of diisopropylbenzene dihydroperoxide controlled at 6%; the obtained second reaction solution is subjected to countercurrent extraction with a sodium hydroxide solution having a mass concentration of 20 wt% of sodium hydroxide to obtain a second oil phase and an aqueous phase;

[0078] (3) After introducing air into the second oil phase obtained in step (2), a first oxidation reaction is carried out in a stirred tank reactor at 150 °C and 1 barg for 2 h to obtain a third reaction solution with the concentration of diisopropylbenzene dihydroperoxide controlled at 6%; the obtained third reaction solution is subjected to countercurrent extraction with a sodium hydroxide solution with a mass concentration of 20 wt% of sodium hydroxide to obtain a third oil phase and an aqueous phase;

[0079] (4) The third oil phase obtained in step (3) is recycled and used in the first oxidation reaction described in step (1), and the specific steps of the recycling include: the third oil phase is mixed with 1,3 - diisopropylbenzene described in step (1), air is introduced, and then the first oxidation reaction is continued; the aqueous phases obtained in step (1), step (2) and step (3) are combined to obtain the diisopropylbenzene dihydroperoxide.

[0080] Example 6

[0081] This example provides a method for preparing diisopropylbenzene dihydroperoxide. The difference from Example 1 is that except that the temperatures of the first oxidation reaction described in step (1), the second oxidation reaction described in step (2) and the third oxidation reaction described in step (3) are all adjusted to 60 °C, the rest are the same as in Example 1.

[0082] Example 7

[0083] This example provides a method for preparing diisopropylbenzene dihydroperoxide. The difference from Example 1 is that except that the temperatures of the first oxidation reaction described in step (1), the second oxidation reaction described in step (2) and the third oxidation reaction described in step (3) are all adjusted to 160 °C, the rest are the same as in Example 1.

[0084] Example 8

[0085] This example provides a method for preparing diisopropylbenzene dihydroperoxide. The difference from Example 1 is that except that the pressures of the first oxidation reaction described in step (1), the second oxidation reaction described in step (2) and the third oxidation reaction described in step (3) are all adjusted to 0.5 barg, the rest are the same as in Example 1.

[0086] Example 9

[0087] This example provides a method for preparing diisopropylbenzene dihydroperoxide. The difference from Example 1 is that except that the pressures of the first oxidation reaction described in step (1), the second oxidation reaction described in step (2) and the third oxidation reaction described in step (3) are all adjusted to 12 barg, the rest are the same as in Example 1.

[0088] Comparative Example 1

[0089] This comparative example provides a method for preparing diisopropylbenzene dihydroperoxide. The difference from Example 1 is that step (3) is not set, and the concentration of diisopropylbenzene dihydroperoxide in the first reaction solution described in step (1) and the second reaction solution described in step (2) is adaptively obtained as 10%, and the rest are the same as in Example 1.

[0090] Comparative Example 2

[0091] This comparative example provides a method for preparing diisopropylbenzene dihydroperoxide. The difference from Example 1 is that before step (4), the following step is added: after introducing air into the third oil phase obtained in step (3), a fourth oxidation reaction is carried out in a stirred autoclave reactor at 100 °C and 4 barg for 10 h to obtain a fourth reaction solution with the concentration of diisopropylbenzene dihydroperoxide controlled at 10%; the obtained fourth reaction solution is subjected to countercurrent extraction with a sodium hydroxide solution with a mass concentration of 9 wt% of sodium hydroxide to obtain a fourth oil phase and an aqueous phase, and step (4) is adaptively adjusted, and the rest are the same as in Example 1.

[0092] Comparative Example 3

[0093] This comparative example provides a method for preparing diisopropylbenzene dihydroperoxide. The preparation method includes the following steps: after introducing air into 1,3 - diisopropylbenzene, an oxidation reaction is carried out in a stirred autoclave reactor at 100 °C and 4 barg for 30 h to obtain a reaction solution with a concentration of diisopropylbenzene dihydroperoxide of 15%; the obtained reaction solution is subjected to countercurrent extraction with a sodium hydroxide solution with a mass concentration of 9 wt% of sodium hydroxide to obtain an oil phase and an aqueous phase, the obtained oil phase is recycled to the oxidation reaction, and the obtained aqueous phase is the diisopropylbenzene dihydroperoxide.

[0094] The product content of the third reaction solutions obtained in Examples 1 - 9 and Comparative Examples 1 - 3 was tested, and the results are shown in Table 1.

[0095] Table 1

[0096]

[0097] As can be seen from Table 1, the preparation method provided by the present invention realizes the preparation of the target product diisopropylbenzene dihydroperoxide through a three - stage oxidation reaction - alkali liquid extraction and separation operation, and has a high yield and good selectivity of the target product, less generation of by - products, and good reaction safety;

[0098] It can be known from the comparison between Example 1 and Examples 6 - 9 that when the temperature and pressure of the oxidation reaction exceed the limited range, it will have an adverse effect on the product yield and the generation amount of by - products; it can be known from the comparison between Example 1 and Comparative Examples 1 - 3 that whether the oxidation reaction is carried out in one stage, two stages or four stages, it will lead to an increase in the generation amount of benzyl alcohol by - products such as MC and HHP.

[0099] In summary, for the preparation method of diisopropylbenzene dihydroperoxide provided by the present invention, the oxidation reaction of diisopropylbenzene is carried out in three stages. The concentration of diisopropylbenzene dihydroperoxide in a single stage can be controlled at a low level, avoiding the disadvantages of a large amount of by-products generated due to deep reaction and the reduction of the yield caused by side reactions of high-concentration diisopropylbenzene dihydroperoxide. At the same time, the total peroxide content in the reaction solution can be effectively reduced, significantly improving the reaction safety, reducing the possibility and severity of the occurrence of a runaway reaction. In addition, the acidic by-products generated in each stage can be neutralized by the base during the alkali extraction process and enter the aqueous phase, without affecting the progress of the oxidation reaction. At the same time, without adding an alkali solution to the reaction solution, the decomposition of peroxides catalyzed by the base to generate benzyl alcohol impurities during the high-temperature reaction can also be effectively reduced. The prepared diisopropylbenzene dihydroperoxide has a high yield, good selectivity and safety in the oxidation reaction, high raw material utilization rate, few side reactions, and excellent industrial application prospects.

[0100] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A preparation method of diisopropylbenzene dihydroperoxide, characterized in that, the preparation method comprises the following steps: (1) After introducing an oxygen-containing gas into diisopropylbenzene, a first oxidation reaction is carried out to obtain a first reaction solution; the obtained first reaction solution is subjected to countercurrent extraction with an alkali solution to obtain a first oil phase and an aqueous phase; (2) After introducing an oxygen-containing gas into the first oil phase obtained in step (1), a second oxidation reaction is carried out to obtain a second reaction solution; the obtained second reaction solution is subjected to countercurrent extraction with an alkali solution to obtain a second oil phase and an aqueous phase; (3) After introducing an oxygen-containing gas into the second oil phase obtained in step (2), a third oxidation reaction is carried out to obtain a third reaction solution; the obtained third reaction solution is subjected to countercurrent extraction with an alkali solution to obtain a third oil phase and an aqueous phase; (4) The third oil phase obtained in step (3) is recycled and used in the first oxidation reaction described in step (1); the aqueous phases obtained in step (1), step (2), and step (3) are combined to obtain the diisopropylbenzene dihydroperoxide.

2. The preparation method according to claim 1, characterized in that, the diisopropylbenzene in step (1) comprises 1,3 - diisopropylbenzene and / or 1,4 - diisopropylbenzene; Preferably, the oxygen-containing gases in step (1), step (2), and step (3) independently include air and / or oxygen respectively.

3. The preparation method according to claim 1 or 2, characterized in that, the temperature of the first oxidation reaction in step (1) is 70 - 150 °C, preferably 85 - 110 °C; Preferably, the pressure of the first oxidation reaction in step (1) is 1 - 10 barg, preferably 2 - 6 barg; Preferably, the time of the first oxidation reaction in step (1) is 2 - 20 h, preferably 3 - 15 h.

4. The preparation method according to any one of claims 1 - 3, characterized in that, the alkali solutions in step (1), step (2), and step (3) independently include sodium hydroxide solutions; Preferably, the mass concentration of sodium hydroxide in the sodium hydroxide solution is 4 - 20 wt%, preferably 6 - 12 wt%.

5. The preparation method according to any one of claims 1 - 4, characterized in that, the temperature of the second oxidation reaction in step (2) is 70 - 150 °C, preferably 80 - 110 °C; Preferably, the pressure of the second oxidation reaction in step (2) is 1 - 10 barg, preferably 2 - 6 barg; Preferably, the time of the second oxidation reaction in step (2) is 2 - 20 h, preferably 3 - 15 h.

6. The preparation method according to any one of claims 1 - 5, characterized in that, the temperature of the third oxidation reaction in step (3) is 70 - 150 °C, preferably 80 - 110 °C; Preferably, the pressure of the third oxidation reaction in step (3) is 1 - 10 barg, preferably 2 - 6 barg; Preferably, the time of the third oxidation reaction in step (3) is 2 - 20 h, preferably 3 - 15 h.

7. The preparation method according to any one of claims 1 - 6, characterized in that, The oxidation reactors used in the first oxidation reaction described in step (1), the second oxidation reaction described in step (2), and the third oxidation reaction described in step (3) each independently include a bubble column or a stirred tank reactor.

8. The preparation method according to any one of claims 1-7, wherein, the concentration of diisopropylbenzene dihydroperoxide in the first reaction liquid described in step (1), the second reaction liquid described in step (2), and the third reaction liquid described in step (3) is all controlled at 5-10%.

9. The preparation method according to any one of claims 1-8, wherein, the specific steps of the recycling in step (4) are as follows: after the third oil phase is mixed with the diisopropylbenzene described in step (1), an oxygen-containing gas is introduced, and then the first oxidation reaction is continued.

10. The preparation method according to any one of claims 1-9, wherein, the preparation method includes the following steps: (1) After introducing air and / or oxygen into 1,3-diisopropylbenzene and / or 1,4-diisopropylbenzene, the first oxidation reaction is carried out in a bubble column or a stirred tank reactor at 70-150 °C and 1-10 barg for 2-20 h to obtain a first reaction liquid with the concentration of diisopropylbenzene dihydroperoxide controlled at 5-10%; the obtained first reaction liquid is subjected to countercurrent extraction with a sodium hydroxide solution with a mass concentration of sodium hydroxide of 4-20 wt% to obtain a first oil phase and an aqueous phase; (2) After introducing air and / or oxygen into the first oil phase obtained in step (1), the second oxidation reaction is carried out in a bubble column or a stirred tank reactor at 70-150 °C and 1-10 barg for 2-20 h to obtain a second reaction liquid with the concentration of diisopropylbenzene dihydroperoxide controlled at 5-10%; the obtained second reaction liquid is subjected to countercurrent extraction with a sodium hydroxide solution with a mass concentration of sodium hydroxide of 4-20 wt% to obtain a second oil phase and an aqueous phase; (3) After introducing air and / or oxygen into the second oil phase obtained in step (2), the third oxidation reaction is carried out in a bubble column or a stirred tank reactor at 70-150 °C and 1-10 barg for 2-20 h to obtain a third reaction liquid with the concentration of diisopropylbenzene dihydroperoxide controlled at 5-10%; the obtained third reaction liquid is subjected to countercurrent extraction with a sodium hydroxide solution with a mass concentration of sodium hydroxide of 4-20 wt% to obtain a third oil phase and an aqueous phase; (4) The third oil phase obtained in step (3) is recycled to the first oxidation reaction described in step (1), and the specific steps of the recycling are as follows: the third oil phase is mixed with 1,3-diisopropylbenzene and / or 1,4-diisopropylbenzene described in step (1), then air and / or oxygen are introduced, and then the first oxidation reaction is continued; the aqueous phases obtained in step (1), step (2), and step (3) are combined to obtain the diisopropylbenzene dihydroperoxide.

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