Heat exchanger for producing peroxide and method for producing peroxide

Abstract

This invention belongs to the field of peroxide preparation technology, specifically relating to a heat exchange device and method for preparing peroxides. The heat exchange device includes heat exchange tubes disposed within a reaction vessel, with several heat exchangers mounted on the heat exchange tubes. Each heat exchanger includes several external fins spaced apart on a fixed plate. The fixed plate has grooves that mate with the heat exchange tubes, and the heat exchange tubes are disposed within these grooves. The peroxide preparation method involves stirring a desensitizer, a catalyst, and an oxidant together, followed by the addition of an alkyl acyl chloride or an alkyl chloroformate to continue the reaction. After the reaction is complete, a crude product is obtained. The crude product is then washed and separated to obtain the peroxide. This invention utilizes the high-efficiency heat transfer performance of the heat exchanger, thereby enabling stable preparation of peroxide products, reducing the reaction time, and improving the conversion efficiency from initial raw materials to peroxide products.

Description

Technical Field

[0001] This invention belongs to the field of peroxide preparation technology, specifically relating to a heat exchange device for preparing peroxides and a method for preparing peroxides. Background Technology

[0002] Peroxides are a class of organic peroxides, belonging to the category of low-temperature organic peroxides. These compounds have important applications in industry and scientific research, such as serving as initiators for polymer polymerization reactions, as free radical initiators and oxidants in organic synthesis, and in rubber crosslinking.

[0003] Peroxides pose certain hazards. They have low decomposition temperatures and are highly explosive, sensitive to impact, heat, and friction. Therefore, special care must be taken during handling to prevent spontaneous combustion or explosion. The production of peroxides often uses alkyl acyl chlorides or alkyl chloroformates as raw materials and hydrogen peroxide as an oxidant for the peroxidation reaction. These substances release a large amount of heat during the reaction, and improper operation can lead to temperature runaway. Peroxide products are highly unstable, and excessively high temperatures can cause combustion or explosion. Therefore, the heat exchange requirements within the reaction vessel are extremely high; the reaction heat must be exchanged within a very short time to prevent the temperature inside the vessel from becoming too high and causing the organic peroxides to decompose.

[0004] Given the strong exothermic phenomenon in the production of peroxide products, the heat exchanger inside the reactor must have high heat exchange efficiency. However, conventional reactors typically use coil heat exchangers, which have low heat exchange efficiency. In the production of organic peroxide products, the performance of the heat exchanger inside the reactor plays a crucial role in the quality of the organic peroxide products, the energy utilization rate of the reactor, and the economy and reliability of the system operation.

[0005] Chinese patent CN106215832A discloses an enhanced heat exchange reactor and a method for enhancing heat exchange in the reactor. The reactor body has a heat exchange transfer pipe, an external heat exchange pipe, and a heat exchange jacket on its outer surface. The external heat exchange pipe, heat exchange jacket, and heat exchange transfer pipe that are adjacent to each other are connected by an internal heat exchange pipe. The internal heat exchange pipes are arranged circumferentially on the inner surface of the reactor body. The external heat exchange pipe, the heat exchange transfer pipe, and the heat exchange jacket are all composed of at least two closed chambers. The heat exchange medium flows sequentially and alternately in the heat exchange jacket, the external heat exchange pipe, the internal heat exchange pipe, and the heat exchange transfer pipe to form a progressive heat exchange cycle.

[0006] The heat exchanger commonly used in this patent employs a finless coil as its main body. The reactants are stirred by a paddle inside the reactor, flowing across the outer surface of the coil for heat exchange. However, the coil has a small heat exchange area, resulting in less than ideal heat transfer performance and low efficiency in actual use. In contrast, the reactants exchange heat on the surface of the coil heat exchanger, and the smooth surface of the coil minimizes turbulence on the fluid.

[0007] Traditional processes for synthesizing peroxide products use alkyl acyl chlorides or alkyl chloroformates and hydrogen peroxide as raw materials, with a strong base as a catalyst. This requires the reactants to be added slowly at low temperatures. Improper operation can easily lead to overheating, potentially causing explosions or fires. Due to the large volume of the reaction vessel and its limited heat transfer efficiency, localized overheating of the reaction solution within the vessel can occur, increasing the risk of runaway. Controlling the temperature within the reaction vessel requires frequent activation of the heat exchange system to balance the temperature, making the process complex.

[0008] With increasing emphasis on environmental protection and safe production, developing safe and efficient organic peroxide synthesis processes is an inevitable trend. Summary of the Invention

[0009] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is to provide a heat exchange device for preparing peroxides, which sets high heat transfer fins in the reaction vessel to safely synthesize peroxides, thereby realizing the safe and efficient synthesis of peroxide products; the present invention also provides a method for preparing peroxides.

[0010] The technical solution adopted by this invention to solve its technical problem is:

[0011] The heat exchange device for preparing peroxides according to the present invention includes a heat exchange tube disposed in a reaction vessel, a plurality of heat exchangers disposed on the heat exchange tube, the heat exchangers including a plurality of external fins, the external fins being spaced apart on a fixed plate, the fixed plate being provided with a groove in conjunction with the heat exchange tube, and the heat exchange tube being disposed inside the groove of the fixed plate.

[0012] in:

[0013] The external fins are vertically arranged on the outside of the fixed plate, and the angle between the long side axis of the external fins and the axis of the heat exchange tube is 0-90°; the grooves are arranged on the inside of the fixed plate, and the grooves include concave grooves, convex grooves and straight grooves.

[0014] When the heat exchange tube is an arc-shaped tube, a fixing plate with an inner concave groove and a fixing plate with an outer convex groove are arranged opposite each other; when the heat exchange tube is a straight tube, two fixing plates with straight grooves are arranged opposite each other; the fixing plate is provided with screw holes to accommodate fixing bolts, the fixing bolts pass through the screw holes to connect the two fixing plates, and a buffer gasket is provided between the fixing bolts and the fixing plates.

[0015] The reactor is equipped with a stirrer, and the top of the stirrer is connected to a motor through the reactor. The top of the reactor is equipped with a raw material inlet and an additive liquid inlet, and the bottom of the reactor is equipped with a discharge port.

[0016] The peroxide preparation method for the aforementioned peroxide heat exchanger includes the following steps:

[0017] S1. Add the desensitizer, catalyst and oxidant to the reaction vessel and stir to react. Then add alkyl acyl chloride or alkyl chloroformate to continue the reaction. After the reaction is completed, the crude product is obtained.

[0018] S2. The crude product is washed and separated to obtain peroxide.

[0019] The method also includes step S3, mixing the peroxide with the additive to obtain the additive-type peroxide; in step S1, the desensitizer is 2-methoxy-2-methylheptane; the catalyst is an aqueous solution of sodium hydroxide or potassium hydroxide, with a catalyst concentration of 20-40 wt%; the oxidant is hydrogen peroxide or tert-butyl hydrogen peroxide, with an oxidant concentration of 27.5-80 wt%.

[0020] In step S1, the alkyl acyl chloride is one or more of 3,5,5-trimethylhexanoyl chloride, isobutyryl chloride, tert-valeryl chloride, isovaleryl chloride, 2-ethoxyacetyl chloride, 2-ethylhexanoyl chloride, lauroyl chloride, decanoyl chloride, benzoyl chloride, 4-methylbenzoyl chloride, or 2,4-dichlorobenzoyl chloride; the alkyl chloroformate is 2-ethylhexyl chloroformate, phenyl chloroformate, benzyl chloroformate, cyclopentyl chloroformate, cyclohexyl chloroformate, isobutyl chloroformate, n-pentyl chloroformate, or 4-tert-butylcyclohexyl chloroformate. One or more of 2-ethoxyethyl chloroformate, 3-methoxybutyl chloroformate, butyl chloroformate, hexadecyl chloroformate, tetradecyl chloroformate, or isopropyl chloroformate; the molar ratio of catalyst to alkyl acyl chloride or alkyl chloroformate is 1.0-1.2:1, the molar ratio of oxidant to alkyl acyl chloride or alkyl chloroformate is 0.5-1.2:1, and the molar ratio of desensitizer to alkyl acyl chloride or alkyl chloroformate is 0.1-1.2:1; the reaction temperature is -5 to 25℃, and the reaction time is 3-6 h.

[0021] In step S2, the washing is done with deionized water, the separation is done by static separation, and the separation is followed by drying and filtration. The drying agent is one of anhydrous sodium sulfate, anhydrous magnesium sulfate, 3A molecular sieve, 5A molecular sieve or alumina desiccant. The amount of desiccant used is 0.8-1.2% of the mass of alkyl acyl chloride or alkyl chloroformate.

[0022] In step S3, the auxiliary agent is an organic solvent or an emulsion. The organic solvent is one or more of 2-methoxy-2-methylheptane, isododecane, cyclohexane, or petroleum ether. The emulsion is composed of deionized water, emulsifier, dispersant, and antifreeze.

[0023] The emulsifier is one of the following: polyoxyethylene hydrogenated castor oil, polyoxyethylene castor oil, stearyl polyoxyethylene ether, fatty alcohol polyoxyethylene polyoxypropylene ether, polyoxypropylene ether, polyoxyethylene polyoxypropylene copolymer, dehydrated sorbitan fatty acid ester, or polysorbate; the dispersant is polyacrylic acid with a molecular weight of 6000-8000; and the antifreeze is ethylene glycol methyl ether or ethylene glycol ethyl ether. Based on 100wt% of the emulsion, the emulsifier dosage is 0.1-2wt%, the dispersant dosage is 0.05-2wt%, and the antifreeze dosage is 5-25wt%.

[0024] In step S3, the auxiliary peroxide is either a solvent-based peroxide or an emulsion-based peroxide. The peroxide content in the solvent-based peroxide is 30-80 wt%, and the peroxide content in the emulsion-based peroxide is 25-60 wt%.

[0025] To improve the safety level of organic peroxide production equipment, this invention solves the problem of uneven temperature control inside the reactor by installing a finned heat exchanger on the coil of the reactor. Radial or axial fins are set on the periphery of the heat exchanger on the reactor coil. By changing the number and size of the fins on the heat exchange coil, the heat exchange efficiency of the coil can be optimized and improved.

[0026] The heat transfer device inside the reactor of this invention can rapidly transfer the large amount of reaction heat generated by the mixing of catalyst, oxidant, and chloroformate compounds within the reactor. This effectively controls the reaction temperature inside the reactor, reduces heat accumulation, and lowers the decomposition risk of thermally unstable organic peroxide products. Furthermore, compared to ordinary heat exchange coils, heat exchange coils with heat exchangers increase the contact area with reactants, resulting in better heat transfer performance. They eliminate the need for secondary processing of the coils, simplify manufacturing, reduce costs, and increase the heat exchange area and surface heat transfer efficiency, thereby increasing the peroxide reaction rate, improving the synthesis efficiency of peroxide products, and reducing COD emissions.

[0027] The beneficial effects of this invention are:

[0028] The external fins of the present invention are vertically arranged on the outside of the fixed plate, and the angle between the long side axis of the external fins and the axis of the heat exchange tube is 0-90°; the grooves are arranged on the inside of the fixed plate, and the grooves include concave grooves, convex grooves and straight grooves.

[0029] When the heat exchange tube of this invention is an arc-shaped tube, a fixing plate with an inner concave groove and a fixing plate with an outer convex groove are arranged opposite each other; when the heat exchange tube is a straight tube, two fixing plates with straight grooves are arranged opposite each other; the fixing plates are provided with screw holes for accommodating fixing bolts, the fixing bolts pass through the screw holes to connect the two fixing plates, and a buffer gasket is provided between the fixing bolts and the fixing plates; the grooves can be fixed to fit the curvature of the coil structure, so that the heat exchanger is fixed on the coil to achieve heat exchange. When the inner concave groove and the outer convex groove are arranged opposite each other, the two grooves form an arc-shaped pipe inside, which is suitable for heat exchange on an arc-shaped coil; when the straight grooves are arranged opposite each other, the two grooves form a straight pipe inside, which is suitable for heat exchange on a straight pipe.

[0030] This invention utilizes the high-efficiency heat transfer performance of a heat exchanger, thereby enabling the stable preparation of peroxide products, reducing the feeding reaction time, and improving the conversion efficiency from initial raw materials to peroxide products.

[0031] This invention features a heat exchanger with externally finned components within the reactor, exhibiting strong heat transfer capabilities. Several externally finned components are arranged parallel to each other, forming narrow channels on the reactor coil. When fluid flows through, it disperses the reaction liquid into a liquid stream, allowing it to fully contact the externally finned components for heat exchange. Combined with materials possessing excellent heat transfer properties, the heat exchange effect is further enhanced. Compared to conventional coil heat exchangers, the effective heat transfer area is increased, and the heat transfer coefficient is improved. Due to the increased heat transfer surface area per unit volume, the heat transfer capacity is enhanced. Under the same heat load, the coil length, coil diameter, or layout height can be reduced, improving the compactness of the reactor structure and facilitating its arrangement.

[0032] The heat exchanger of this invention has a compact structure, uses fewer materials, and allows for flexible selection of heat exchanger materials to meet different heat transfer and process requirements. By selecting materials with good heat transfer performance and combining them with external fins at different angles, heat transfer efficiency can be further improved.

[0033] Effective control of temperature changes inside the reactor can reduce the decomposition and damage of organic peroxide products in local high-temperature environments, thereby improving the yield and quality of organic peroxide products.

[0034] This invention employs a fixed combination of several external fins, reducing fin production costs, simplifying the process, and offering flexible and convenient installation. It improves the reaction rate, enables timely heat dissipation, shortens the overall reaction time, and avoids localized overheating. It effectively prevents side reactions and reduces safety hazards caused by the instability of peroxides.

[0035] The external fins of this invention can also improve the dispersion effect of the mixture, increase the specific surface area of ​​the mixture, further improve the mixing efficiency and safe production of the peroxide product synthesis process, and reduce the accident risks of thermal decomposition of peroxide products.

[0036] This invention uses a desensitizing agent to prepare peroxide products, which can prevent the decomposition of substances during the reaction process. The desensitizing agent ensures safe and efficient production and synthesis of peroxide products. The desensitizing agent can extract the synthesized peroxide products from the aqueous phase in a timely manner, preventing the peroxide products from being decomposed by impurities in the aqueous phase and improving the yield of peroxide products. Peroxide products containing desensitizing agents are more likely to form water-emulsion products with emulsifier mother liquor, and can be mixed to prepare water-emulsion alkyl peroxides or solvent-based alkyl peroxides, which can meet the peroxide transportation classification requirements.

[0037] The prepared water-emulsion peroxide product uses a water-based polyacrylic acid dispersant, resulting in a water-emulsion peroxide product with low viscosity, which is easier to disperse in the PVC polymerization system and more suitable for the PVC polymerization process.

[0038] More importantly, the use of 2-methoxy-2-methylheptane as a peroxide desensitizer in this invention has a good desensitizing effect.

[0039] 1. 2-Methoxy-2-methylheptane has good miscibility with peroxide products. The mixture of 2-methoxy-2-methylheptane and peroxide products has good stability and compatibility. By diluting the peroxide, its energy release rate can be reduced.

[0040] 2. The 2-methoxy-2-methylheptane molecule has both a tertiary carbon group and an ether bond. Its chemical structure is similar to that of the tert-butyl or tertiary carbon alkyl group in peroxide products. It can form an adsorption system through physical adsorption and hydrogen bonding, thereby reducing the activity of peroxide molecules and reducing the risk of peroxide molecules decomposing due to heat, light or mechanical stimulation.

[0041] 3. Adding 2-methoxy-2-methylheptane before the reaction is beneficial to the peroxidation reaction of alkyl acyl chlorides or alkyl chloroformates, because the tertiary carbon group and ether bond on its molecule are more conducive to the formation of peroxide molecules, thus acting as a template agent.

[0042] 4. The 2-methoxy-2-methylheptane molecule contains one oxygen atom, which has strong electronegativity, increasing the reactivity of its α-hydrogen atom. This active hydrogen atom can react with free radicals generated from the decomposition of peroxides to form stable free radicals, thereby blocking the oxidation chain reaction and preventing the decomposition of peroxides. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the reactor structure of the present invention;

[0044] Figure 2 This is a schematic diagram of the heat exchanger of the present invention installed in a straight tube;

[0045] Figure 3This is a schematic diagram of the heat exchanger of the present invention installed in an arc-shaped tube structure;

[0046] Figure 4 This is a schematic cross-sectional view of the heat exchanger of the present invention;

[0047] Figure 5 This is a schematic diagram of the heat exchanger structure with straight grooves according to the present invention. Figure 1 ;

[0048] Figure 6 This is a schematic diagram of the heat exchanger structure with straight grooves according to the present invention. Figure 2 ;

[0049] Figure 7 This is a schematic diagram of the heat exchanger structure with concave grooves of the present invention. Figure 1 ;

[0050] Figure 8 This is a schematic diagram of the heat exchanger structure with an outwardly convex groove according to the present invention. Figure 1 ;

[0051] Figure 9 This is a schematic diagram of the heat exchanger structure with concave grooves of the present invention. Figure 2 ;

[0052] Figure 10 This is a schematic diagram of the heat exchanger structure with an outwardly convex groove according to the present invention. Figure 2 ;

[0053] In the diagram: 1. Heat exchange tube; 2. Fixing bolt; 3. Heat exchanger; 4. Buffer gasket; 5. Reactor; 6. Stirrer; 7. Motor; 8. Additive inlet; 9. Raw material inlet; 10. Discharge outlet; 301. External fins; 302. Fixing plate; 303. Screw hole; 3021. Inner concave groove; 3022. Outer convex groove; 3023. Straight groove. Detailed Implementation

[0054] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0055] Example 1

[0056] like Figure 1 , 4 As shown in Figures 5, 9, and 10, the heat exchange device for preparing peroxides according to the present invention includes a heat exchange tube 1 disposed in a reaction vessel 5. A plurality of heat exchangers 3 are disposed on the heat exchange tube 1. Each heat exchanger 3 includes a plurality of external fins 301. The external fins 301 are spaced apart on a fixed plate 302. The fixed plate 302 is provided with a groove in cooperation with the heat exchange tube 1. The heat exchange tube 1 is disposed inside the groove of the fixed plate 302.

[0057] The external fins 301 are vertically arranged on the outside of the fixed plate 302, and the angle between the long side axis of the external fins 301 and the axis of the heat exchange tube 1 is 0°; the groove is arranged on the inside of the fixed plate 302, and the groove includes an inner concave groove 3021, an outer convex groove 3022 and a straight groove 3023.

[0058] When the heat exchange tube 1 is an arc-shaped tube, the fixing plate 302 with an inner concave groove 3021 and the fixing plate 302 with an outer convex groove 3022 are arranged opposite to each other; when the heat exchange tube 1 is a straight tube, the two fixing plates 302 with straight grooves 3023 are arranged opposite to each other; the fixing plate 302 is provided with a screw hole 303 for accommodating the fixing bolt 2, the fixing bolt 2 passes through the screw hole 303 to connect the two fixing plates 302, and a buffer pad 4 is provided between the fixing bolt 2 and the fixing plate 302.

[0059] A stirrer 6 is installed inside the reactor 5. A motor 7 is connected to the top of the stirrer 6 through the reactor 5. A raw material inlet 9 and an additive liquid inlet 8 are provided at the top of the reactor 5. A discharge port 10 is provided at the bottom of the reactor 5.

[0060] A method for preparing peroxides using a heat exchanger for preparing peroxides includes the following steps:

[0061] S1. 12 kg of 2-methoxy-2-methylheptane, 7.82 kg of 40 wt% sodium hydroxide and 4.6 kg of 27.5 wt% hydrogen peroxide were added to reactor 5 and stirred to react. Then, 13 kg of 3,5,5-trimethylhexanoyl chloride was slowly added and the reaction was continued at 10 °C for 6 h. After the reaction was completed, the crude product was obtained.

[0062] S2. The crude product was washed with 13 kg of deionized water for 20 min by stirring, allowed to stand for separation, and the above operation was repeated once. Then, 0.13 kg of anhydrous sodium sulfate was added for drying, and the product was filtered to obtain bis(3,5,5-trimethylhexanoyl) peroxide containing 2-methoxy-2-methylheptane, with a yield of 93.1 wt%.

[0063] S3. Take a portion of bis(3,5,5-trimethylhexanoyl chloride) peroxide and mix it with 2-methoxy-2-methylheptane to obtain 3 kg of solvent-based bis(3,5,5-trimethylhexanoyl) peroxide with a content of 40 wt%.

[0064] Example 2

[0065] like Figure 1 , 2 As shown in Figures 3, 6, 7, and 8, the angle between the long side axis of the external fin 301 and the axis of the heat exchange tube 1 in the heat exchange device for preparing peroxides is 90°; the rest of the structure is the same as in Example 1.

[0066] Emulsion preparation:

[0067] Mix 72.5 kg of deionized water, 25 kg of ethylene glycol methyl ether, 2 kg of polyoxyethylene castor oil, and 0.5 kg of water-based polyacrylic acid dispersant with a molecular weight of 6000, and stir evenly at room temperature to obtain an emulsion.

[0068] A method for preparing peroxides using a heat exchanger for preparing peroxides includes the following steps:

[0069] S1. Add 4 kg of 2-methoxy-2-methylheptane, 7.72 kg of 40 wt% sodium hydroxide and 5.2 kg of 27.5 wt% hydrogen peroxide to reactor 5 and stir to react. Then slowly add 12 kg of 3,5,5-trimethylhexanoyl chloride and continue to react at 20 °C for 4 h. After the reaction is completed, crude product is obtained.

[0070] S2. The crude product was washed with 10 kg of deionized water for 20 min by stirring, allowed to stand for separation, and the above operation was repeated once. Then, 0.12 kg of anhydrous sodium sulfate was added for drying, and the product was filtered to obtain bis(3,5,5-trimethylhexanoyl) peroxide containing 2-methoxy-2-methylheptane, with a yield of 93.5 wt%.

[0071] S3. Take a portion of bis(3,5,5-trimethylhexanoyl) peroxide and mix it with the emulsion to obtain 3 kg of water-emulsion type bis(3,5,5-trimethylhexanoyl) peroxide with a content of 60 wt%.

[0072] Example 3

[0073] In the heat exchanger used to prepare peroxides, the angle between the long side axis of the external fin 301 and the axis of the heat exchange tube 1 is 45°; the rest of the structure is the same as in Example 1.

[0074] A method for preparing peroxides using a heat exchanger for preparing peroxides includes the following steps:

[0075] S1. Add 4.5 kg of 2-methoxy-2-methylheptane, 16.7 kg of 35 wt% sodium hydroxide and 7.87 kg of 27.5 wt% hydrogen peroxide to reactor 5 and stir to react. Then slowly add 13 kg of isobutyryl chloride and continue to react at 0 °C for 3 h. After the reaction is completed, crude product is obtained.

[0076] S2. The crude product was washed with 10 kg of deionized water for 20 min by stirring, allowed to stand for separation, and the above operation was repeated once. Then, 0.11 kg of 3A molecular sieve was added for drying, and the product was filtered to obtain diisobutyryl peroxide containing 2-methoxy-2-methylheptane, with a yield of 96.6 wt%.

[0077] S3. Take a portion of diisobutyryl peroxide and mix it with 2-methoxy-2-methylheptane to obtain 3 kg of solvent-type diisobutyryl peroxide with a diisobutyryl peroxide content of 30 wt%.

[0078] Example 4

[0079] Emulsion preparation:

[0080] Mix 78 kg of deionized water, 20 kg of ethylene glycol methyl ether, 1 kg of polyoxyethylene castor oil, and 1 kg of water-based polyacrylic acid dispersant with a molecular weight of 7500, and stir evenly at room temperature to obtain an emulsion.

[0081] The method for preparing peroxides for using peroxide heat exchangers includes the following steps:

[0082] S1. Add 4 kg of 2-methoxy-2-methylheptane, 16.1 kg of 30 wt% sodium hydroxide and 7.47 kg of 27.5 wt% hydrogen peroxide to reactor 5 and stir to react. Then slowly add 13 kg of isobutyryl chloride and continue to react at -5℃ for 4 h. After the reaction is completed, crude product is obtained.

[0083] S2. The crude product was washed with 10 kg of deionized water for 20 min by stirring, allowed to stand for separation, and the above operation was repeated once. Then, 0.13 kg of anhydrous magnesium sulfate was added for drying, and the product was filtered to obtain diisobutyryl peroxide containing 2-methoxy-2-methylheptane, with a yield of 96.3 wt%.

[0084] S3. Take a portion of diisobutyryl peroxide and mix it with the emulsion to obtain 3 kg of water-emulsion diisobutyryl peroxide with a diisobutyryl peroxide content of 25 wt%.

[0085] Example 5

[0086] The method for preparing peroxides for using peroxide heat exchangers includes the following steps:

[0087] S1. Add 3 kg of 2-methoxy-2-methylheptane, 7.36 kg of 40 wt% sodium hydroxide and 6.81 kg of 27.5 wt% hydrogen peroxide to reactor 5 and stir to react. Then slowly add 12 kg of 2-ethylhexyl chloroformate and continue to react at 10 °C for 4 h. After the reaction is completed, the crude product is obtained.

[0088] S2. The crude product was washed with 11 kg of deionized water for 20 min by stirring, allowed to stand for separation, and the above operation was repeated once. Then, 0.11 kg of anhydrous sodium sulfate was added for drying, and the product was filtered to obtain di(2-ethylhexyl) peroxide dicarbonate containing 2-methoxy-2-methylheptane, with a yield of 94.9 wt%.

[0089] S3. Take a portion of di(2-ethylhexyl) peroxide dicarbonate and mix it with 2-methoxy-2-methylheptane to obtain 3 kg of solvent-type di-2-ethylhexyl peroxide dicarbonate, with a content of 70 wt%.

[0090] Example 6

[0091] Emulsion preparation:

[0092] Mix 77.5 kg of deionized water, 20 kg of ethylene glycol methyl ether, 2 kg of polyoxyethylene castor oil, and 0.5 kg of water-based polyacrylic acid dispersant with a molecular weight of 8000, and stir evenly at room temperature to obtain an emulsion.

[0093] The method for preparing peroxides for using peroxide heat exchangers includes the following steps:

[0094] S1. Add 4 kg of 2-methoxy-2-methylheptane, 6.92 kg of 40 wt% sodium hydroxide and 4.81 kg of 27.5 wt% hydrogen peroxide to reactor 5 and stir to react. Then slowly add 12 kg of 2-ethylhexyl chloroformate and continue to react at 20 °C for 4 h. After the reaction is completed, crude product is obtained.

[0095] S2. The crude product was washed with 11 kg of deionized water for 20 min by stirring, allowed to stand for separation, and the above operation was repeated once. Then, 0.11 kg of alumina desiccant was added for drying, and the product was filtered to obtain di(2-ethylhexyl) peroxide dicarbonate containing 2-methoxy-2-methylheptane, with a yield of 94.1 wt%.

[0096] S3. Take a portion of di(2-ethylhexyl) peroxide dicarbonate and mix it with the emulsion to obtain 3 kg of water-emulsion type di-2-ethylhexyl peroxide dicarbonate, with a di(2-ethylhexyl) peroxide dicarbonate content of 40 wt%.

[0097] Example 7

[0098] The method for preparing peroxides for using peroxide heat exchangers includes the following steps:

[0099] S1. Add 5 kg of 2-methoxy-2-methylheptane, 12.38 kg of 30 wt% sodium hydroxide and 5.13 kg of 27.5 wt% hydrogen peroxide to reactor 5 and stir to react. Then slowly add 12 kg of 2-ethoxyethyl chloroformate and continue to react at 25 °C for 5 h. After the reaction is completed, crude product is obtained.

[0100] S2. The crude product was washed with 10 kg of deionized water for 20 min by stirring, allowed to stand for separation, and the above operation was repeated once. Then, 0.13 kg of anhydrous magnesium sulfate was added for drying, and the product was filtered to obtain di(2-ethoxy)ethyl peroxide containing 2-methoxy-2-methylheptane, with a yield of 96.2 wt%.

[0101] S3. Take a portion of di(2-ethoxy)ethyl peroxide and mix it with 2-methoxy-2-methylheptane to obtain 3 kg of solvent-type di(2-ethoxy)ethyl peroxide, with a di(2-ethoxy)ethyl peroxide content of 50 wt%.

[0102] Example 8

[0103] Emulsion preparation:

[0104] Mix 83 kg of deionized water, 15 kg of ethylene glycol methyl ether, 1.5 kg of polyoxyethylene castor oil, and 0.5 kg of water-based polyacrylic acid dispersant with a molecular weight of 8000, and stir evenly at room temperature to obtain an emulsion.

[0105] The method for preparing peroxides for using peroxide heat exchangers includes the following steps:

[0106] S1. Add 3 kg of 2-methoxy-2-methylheptane, 8.13 kg of 40 wt% sodium hydroxide and 8.63 kg of 27.5 wt% hydrogen peroxide to reactor 5 and stir to react. Then slowly add 12 kg of 3-methoxybutyl chloroformate and continue to react at 15 °C for 3 h. After the reaction is completed, crude product is obtained.

[0107] S2. The crude product was washed with 10 kg of deionized water for 20 min by stirring, allowed to stand for separation, and the above operation was repeated once. Then, 0.12 kg of anhydrous sodium sulfate was added for drying, and the product was filtered to obtain bis(3-methoxybutyl) peroxide dicarbonate with a yield of 96.7 wt%.

[0108] S3. Take a portion of bis(3-methoxybutyl) peroxide and mix it with the emulsion to obtain 3 kg of water-emulsion bis(3-methoxybutyl) peroxide, with a content of 50 wt%.

[0109] Example 9

[0110] The method for preparing peroxides for using peroxide heat exchangers includes the following steps:

[0111] S1. 1.5 kg of 2-methoxy-2-methylheptane, 13.54 kg of 30 wt% sodium hydroxide and 11.1 kg of 80 wt% tert-butyl hydroperoxide were added to reactor 5 and stirred to react. Then, 12 kg of tert-valeryl chloride was slowly added and the reaction was continued at 20 °C for 3 h. After the reaction was completed, the crude product was obtained.

[0112] S2. The crude product was washed with 10 kg of deionized water for 20 min by stirring, allowed to stand for separation, and the above operation was repeated once. Then, 0.12 kg of anhydrous magnesium sulfate was added for drying, and the product was filtered to obtain tert-butyl peroxypentanoate containing 2-methoxy-2-methylheptane, with a yield of 91.7 wt%.

[0113] S3. Take a portion of tert-butyl peroxypentanoate and mix it with 2-methoxy-2-methylheptane to obtain 3 kg of solvent-based tert-butyl peroxypentanoate with a content of 80 wt%.

[0114] Example 10

[0115] The method for preparing peroxides for using peroxide heat exchangers includes the following steps:

[0116] S1. 0.8 kg of 2-methoxy-2-methylheptane, 7.85 kg of 30 wt% sodium hydroxide and 6.61 kg of 70 wt% tert-butyl hydrogen peroxide were added to reactor 5 and stirred to react. Then, 10 kg of 2-ethylhexyl chloroformate was slowly added and the reaction was continued at 15 °C for 5 h. After the reaction was completed, the crude product was obtained.

[0117] S2. The crude product was stirred and washed with 10 kg of deionized water for 20 min, allowed to stand and separate, and the above operation was repeated. Then, 0.12 kg of anhydrous sodium sulfate was added for drying, and the product was filtered to obtain tert-butyl peroxide-2-ethylhexyl carbonate with a yield of 97.8 wt%.

[0118] Example 11

[0119] The method for preparing peroxides for using peroxide heat exchangers includes the following steps:

[0120] S1. 1.2 kg of 2-methoxy-2-methylheptane, 18.16 kg of 20 wt% sodium hydroxide and 10.4 kg of 70 wt% tert-butyl hydrogen peroxide were added to reactor 5 and stirred to react. Then, 10 kg of isopropyl chloroformate was slowly added and the reaction was continued at 20 °C for 4 h. After the reaction was completed, the crude product was obtained.

[0121] S2. The crude product was washed with 10 kg of deionized water for 20 min by stirring, allowed to stand for separation, and the above operation was repeated once. Then, 0.1 kg of anhydrous sodium sulfate was added for drying, and the product was filtered to obtain tert-butyl peroxide carbonate with a yield of 97.4 wt%.

[0122] S3. Take a portion of tert-butyl peroxyisopropyl carbonate and mix it with 2-methoxy-2-methylheptane to obtain 3 kg of solvent-based tert-butyl peroxyisopropyl carbonate with a content of 60 wt%.

[0123] In Examples 4-11, the structure of the heat exchange device for preparing peroxides is the same as in Example 1.

[0124] Comparative Example 1

[0125] In step S1, 2-methoxy-2-methylheptane was not added, and the remaining operations were the same as in Example 1, with a yield of 82.3%.

[0126] Comparative Example 2

[0127] The heat exchanger used in the preparation of peroxides did not use heat exchanger 3, and the remaining steps were the same as in Example 1, with a yield of 84.7 wt%.

[0128] In summary, as shown in Comparative Example 1 and Example 1, the desensitizing agent added in this invention can prevent the peroxide product from being decomposed by aqueous impurities during the reaction process, thereby improving the yield of the peroxide product. As shown in Comparative Example 2 and Example 1, the addition of a heat exchanger 3 with external fins 301 to the reaction vessel 5 in this invention can improve heat transfer efficiency, promote the forward reaction of the peroxide, and improve the product yield. This invention is applicable to the production of a variety of substances, has a wide range of applications, and improves the efficiency of substance synthesis.

Claims

1. A method for preparing peroxides using a heat exchange device, characterized in that, Includes the following steps: S1. Add the desensitizer, catalyst and oxidant to the reaction vessel (5) and stir to react. Then add alkyl acyl chloride or alkyl chloroformate to continue the reaction. After the reaction is completed, the crude product is obtained. S2. The crude product is washed and separated to obtain peroxide; S3. Mix the peroxide with the additive to obtain the additive-type peroxide; In step S1, the desensitizer is 2-methoxy-2-methylheptane, the catalyst concentration is 20-40 wt%, and the oxidant concentration is 27.5-80 wt%. The molar ratio of catalyst to alkyl acyl chloride or alkyl chloroformate is 1.0-1.2:1, the molar ratio of oxidant to alkyl acyl chloride or alkyl chloroformate is 0.5-1.2:1, and the molar ratio of desensitizer to alkyl acyl chloride or alkyl chloroformate is 0.1-1.2:

1. The reaction temperature is -5 to 25℃, and the reaction time is 3-6 h. The heat exchange device includes a heat exchange tube (1) installed in the reactor (5), and a plurality of heat exchangers (3) are installed on the heat exchange tube (1). The heat exchangers (3) include a plurality of external fins (301). The external fins (301) are spaced apart on the fixed plate (302). The fixed plate (302) is provided with a groove in cooperation with the heat exchange tube (1). The heat exchange tube (1) is installed inside the groove of the fixed plate (302). The external fins (301) are vertically arranged on the outside of the fixed plate (302), and the angle between the long side axis of the external fins (301) and the axis of the heat exchange tube (1) is 0-90°; the grooves are arranged on the inside of the fixed plate (302), and the grooves include concave grooves (3021), convex grooves (3022) and straight grooves (3023).

2. The method for preparing peroxides using a heat exchange device according to claim 1, characterized in that, When the heat exchange tube (1) is an arc-shaped tube, a fixing plate (302) with an inner concave groove (3021) and a fixing plate (302) with an outer convex groove (3022) are arranged opposite to each other; when the heat exchange tube (1) is a straight tube, two fixing plates (302) with straight grooves (3023) are arranged opposite to each other; a screw hole (303) for accommodating a fixing bolt (2) is provided on the fixing plate (302), the fixing bolt (2) passes through the screw hole (303) to connect the two fixing plates (302), and a buffer pad (4) is provided between the fixing bolt (2) and the fixing plate (302).

3. The method for preparing peroxides using a heat exchange device according to claim 1, characterized in that, A stirrer (6) is installed inside the reactor (5). The top of the stirrer (6) passes through the reactor (5) and is connected to a motor (7). The top of the reactor (5) is provided with a raw material inlet (9) and an additive liquid inlet (8). The bottom of the reactor (5) is provided with a discharge port (10).

4. The method for preparing peroxides using a heat exchange device according to claim 1, characterized in that, In step S1, the catalyst is an aqueous solution of sodium hydroxide or potassium hydroxide; the oxidant is hydrogen peroxide or tert-butyl hydrogen peroxide.

5. The method for preparing peroxides using a heat exchange device according to claim 1, characterized in that, In step S1, the alkyl acyl chloride is one or more of 3,5,5-trimethylhexanoyl chloride, isobutyryl chloride, tert-valeryl chloride, isovaleryl chloride, 2-ethoxyacetyl chloride, 2-ethylhexanoyl chloride, lauroyl chloride, decanoyl chloride, benzoyl chloride, 4-methylbenzoyl chloride, or 2,4-dichlorobenzoyl chloride; the alkyl chloroformate is one or more of 2-ethylhexyl chloroformate, phenyl chloroformate, benzyl chloroformate, cyclopentyl chloroformate, cyclohexyl chloroformate, isobutyl chloroformate, n-pentyl chloroformate, 4-tert-butylcyclohexyl chloroformate, 2-ethoxyethyl chloroformate, 3-methoxybutyl chloroformate, butyl chloroformate, hexadecyl chloroformate, tetradecyl chloroformate, or isopropyl chloroformate.

6. The method for preparing peroxides using a heat exchange device according to claim 1, characterized in that, In step S2, the washing is done with deionized water, the separation is done by static separation, and the separation is followed by drying and filtration. The drying agent is one of anhydrous sodium sulfate, anhydrous magnesium sulfate, 3A molecular sieve, 5A molecular sieve or alumina desiccant. The amount of desiccant used is 0.8-1.2% of the mass of alkyl acyl chloride or alkyl chloroformate.

7. The method for preparing peroxides using a heat exchange device according to claim 1, characterized in that, In step S3, the auxiliary agent is an organic solvent or an emulsion. The organic solvent is one or more of 2-methoxy-2-methylheptane, isododecane, cyclohexane, or petroleum ether. The emulsion is composed of deionized water, emulsifier, dispersant, and antifreeze. The emulsifier is one of the following: polyoxyethylene hydrogenated castor oil, polyoxyethylene castor oil, stearyl polyoxyethylene ether, fatty alcohol polyoxyethylene polyoxypropylene ether, polyoxypropylene ether, polyoxyethylene polyoxypropylene copolymer, dehydrated sorbitan fatty acid ester, or polysorbate; the dispersant is polyacrylic acid with a molecular weight of 6000-8000; and the antifreeze is ethylene glycol methyl ether or ethylene glycol ethyl ether. Based on 100wt% of the emulsion, the emulsifier dosage is 0.1-2wt%, the dispersant dosage is 0.05-2wt%, and the antifreeze dosage is 5-25wt%.

8. The method for preparing peroxides using a heat exchange device according to claim 1, characterized in that, In step S3, the auxiliary peroxide is either a solvent-based peroxide or an emulsion-based peroxide. The peroxide content in the solvent-based peroxide is 30-80 wt%, and the peroxide content in the emulsion-based peroxide is 25-60 wt%.

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