Pipeline continuous production device and method for preparing benzoyl peroxide

Abstract

The invention relates to a pipeline continuous production device and method for preparing benzoyl peroxide, the device comprises a material storage tank, an automatic sample injector and a pipeline reactor which are sequentially connected in the material direction, the pipeline reactor comprises a conveying pipe and a spiral conveyor, the spiral conveyor is sleeved with the conveying pipe, and the conveying pipe and the spiral conveyor are coaxial; a feed port and a discharge port are respectively formed in two ends of the conveying pipe, the pipeline reactor is obliquely arranged, the discharge port is higher than the feed port, and the storage tank, the automatic sample injector and the pipeline reactor are connected through a pipeline. The method comprises the following steps: conveying a material loaded in the material storage tank into the pipeline reactor by the automatic sample injector; the materials react in the pipeline reactor and are conveyed to a discharge port through a spiral conveyor to obtain a crude product; and filtering, washing and draining the obtained crude product to obtain the final product benzoyl peroxide. Compared with the prior art, the method has the advantages that the purity, the yield, the output and the productivity of benzoyl peroxide are improved, the safety of the production process is improved, the production cost is reduced and the like.

Description

Technical Field

[0001] The invention relates to the technical field of chemical industry, and in particular to a pipeline continuous production device and method for preparing benzoyl peroxide. Background Art

[0002] Benzoyl peroxide is a strong oxidant that can quickly reduce inflammation and kill bacteria, relieve acne symptoms, and effectively dissolve keratin, inhibit excess oil secretion, prevent pore occlusion, and effectively prevent acne formation. The existing benzoyl peroxide production process is mostly intermittent batch reaction production, and the production process requires frequent replacement of reactors and a large amount of washing and separation operations, resulting in low production efficiency, high energy consumption and unstable product quality. Benzoyl peroxide with many impurities and poor purity cannot meet the needs of the high-end market. Therefore, it is necessary to develop a new preparation process to improve the purity and yield of benzoyl peroxide and reduce production costs.

[0003] Patent Publication No. CN102199115B discloses a method for preparing benzoyl peroxide, including the steps of: preparing a benzoyl peroxide primary product; preparing a finished benzoyl peroxide product, first rinsing the benzoyl peroxide primary product, and then introducing a solid-liquid separation device for solid-liquid separation to obtain a finished benzoyl peroxide product. The method utilizes a first reaction device and a next-stage reaction device to produce a benzoyl peroxide primary product, and the two reaction devices are connected in series, so that the purpose of raw material introduction and benzoyl peroxide primary product export can be achieved. The method is essentially a one-pot method for producing benzoyl peroxide, and when the material reaches the reaction time in the second reaction device, the benzoyl peroxide primary product can be obtained at one time. Since the volume of the two reaction devices is fixed, the amount of material that can be loaded has an upper limit, so the method is difficult to expand production capacity. If the volume of the reaction device is blindly increased, there will be a risk of explosion during the production of peroxide products due to difficulty in temperature control during the production process. The process of producing benzoyl peroxide by a one-pot method limits the output of benzoyl peroxide produced in a single batch. Summary of the invention

[0004] The purpose of the present invention is to provide a pipeline continuous production device and method for preparing benzoyl peroxide in order to overcome the defects of the above-mentioned prior art, improve the purity, yield, output and production capacity of benzoyl peroxide, improve the safety of the production process, and reduce production costs.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] In one aspect, the present invention provides a pipeline continuous production device for preparing benzoyl peroxide, comprising a storage tank, an automatic sampler, and a pipeline reactor connected in sequence along a material direction, wherein the pipeline reactor comprises a delivery pipe and a screw conveyor, the delivery pipe is sleeved outside the screw conveyor and is coaxial with the screw conveyor, a feed port and a discharge port are respectively arranged at both ends of the delivery pipe, the pipeline reactor is tilted so that the height of the discharge port is higher than the height of the feed port, and the storage tank, the automatic sampler, and the pipeline reactor are connected by a pipeline.

[0007] Furthermore, the material in direct contact with the material in the pipeline continuous production device is acid-resistant, alkali-resistant and corrosion-resistant material, including stainless steel, titanium alloy, glass, ceramic, enamel, polytetrafluoroethylene, polyethylene (PE), polypropylene (PP), and random copolymer polypropylene (PPR).

[0008] Furthermore, the connection parts of the storage tank, the automatic sampler and the pipeline are equipped with tightly connected joints to prevent liquid from leaking from the connection parts, wherein the automatic sampler needs to achieve a leak-free performance.

[0009] Furthermore, the storage tanks include a first storage tank loaded with a sodium carbonate aqueous solution containing sodium dodecyl sulfate, a second storage tank loaded with hydrogen peroxide, and a third storage tank loaded with benzoyl chloride.

[0010] Furthermore, the automatic sampler includes a first delivery pump for delivering sodium carbonate aqueous solution of sodium dodecyl sulfate, a second delivery pump for delivering hydrogen peroxide, and a third delivery pump for delivering benzoyl chloride. The automatic sampler can control the temperature, pressure and flow rate of the materials during delivery, and can also independently control the delivery rate of each material, so that multiple materials can be added in molar ratio, mass ratio or volume ratio.

[0011] Furthermore, the feed port and the discharge port are located on the same side or both sides of the conveying pipe, and the openings are upward or downward. The pipeline reactor is placed obliquely so that the height of the discharge port is higher than that of the feed port to ensure the reaction time of the material in the pipeline reactor, and the material is transported forward along the conveying pipe under the push of the screw conveyor.

[0012] Furthermore, the discharge port should be inclined upward at an angle of 5 to 60° relative to the feed port; preferably, the upward angle should be 10 to 30°.

[0013] Furthermore, a first jacket that can be heated or cooled is disposed outside the delivery pipe of the pipeline reactor, and a first thermal insulation layer is disposed outside the first jacket.

[0014] Furthermore, water of different temperatures is added to the first jacket or a heating wire is placed therein to control the temperature of the pipeline reactor, and the first insulation layer is used to prevent heat loss or external heat intrusion, thereby controlling the temperature of the pipeline reactor.

[0015] Furthermore, a sealing assembly is provided at the connection between the delivery pipe of the pipeline reactor and the screw conveyor.

[0016] Furthermore, the screw conveyor comprises:

[0017] The motor that provides the power;

[0018] Bearings that play a supporting role;

[0019] A shaft for rotation;

[0020] And the rotating blades are responsible for moving the material.

[0021] Furthermore, the length of the delivery pipe is 1 to 10 m, and the outer diameter is 10 to 80 cm; further, the length is 2 to 3 m, and the outer diameter is 20 to 30 cm.

[0022] Furthermore, the length of the screw conveyor is 1 to 10 m, and further, the length is 2 to 3 m. The inner diameter of the screw conveyor is between 10 and 80 cm, and further, the inner diameter is 20 to 30 cm.

[0023] Furthermore, the outer diameter of the screw conveyor is smaller than the inner diameter of the conveying pipe.

[0024] The screw conveyor has a pitch of 1 to 50 cm, and more preferably, a pitch of 5 to 20 cm. The screw conveyor has a rotation speed of 10 to 500 rpm, and more preferably, a rotation speed of 50 to 150 rpm.

[0025] Various parameters of the conveying pipe and the screw conveyor can be adaptively adjusted to meet the needs of the production process.

[0026] Furthermore, a mixer is provided between the automatic sampler and the pipeline reactor, which comprises:

[0027] Reactor;

[0028] An agitator is arranged inside the reactor, wherein the agitator is provided with a plurality of agitating blades in a vertical direction and distributed at the upper, middle and lower positions of the reactor;

[0029] A first input port, a second input port, and a third input port directly connected to the bottom of the reactor, and the first input port, the second input port, and the third input port are connected to the automatic sample injector;

[0030] An output port connected to the feed port of the pipeline reactor.

[0031] Furthermore, the volume of the reactor is 0.02-200L; further, 1-50L, preferably 2-20L.

[0032] Furthermore, a second jacket capable of being heated or cooled is disposed outside the reactor, and a second heat insulating layer is disposed outside the second jacket.

[0033] Furthermore, water of different temperatures is added to the second jacket or a heating wire is placed therein to control the temperature of the reactor, and the second thermal insulation layer is used to prevent heat loss or external heat intrusion, thereby controlling the temperature of the reactor.

[0034] Furthermore, the output port is arranged at the upper end of the side of the reactor. As the material is continuously added, the liquid level in the reactor rises. When the liquid level reaches the output port, the uniformly mixed material overflows from the output port; the overflowed material enters the pipeline reactor. The mixing time of the material can be controlled by controlling the volume and feeding speed of the mixer. Before a large amount of sediment appears, the material should be discharged from the output port and enter the pipeline reactor.

[0035] On the other hand, the present invention also provides a pipeline continuous production method for preparing benzoyl peroxide, which is implemented using the above-mentioned device, and the method comprises the following steps:

[0036] A1, the automatic sampler delivers the material loaded in the storage tank to the pipeline reactor according to a certain molar ratio;

[0037] A2. While the material is reacting in the pipeline reactor, it is transported to the discharge port by the screw conveyor to obtain a crude product;

[0038] A3. The obtained crude product is filtered, washed and dried to obtain the final product benzoyl peroxide.

[0039] Furthermore, the first storage tank is loaded with a sodium carbonate aqueous solution containing 0.1 wt% to 50 wt% of sodium dodecyl sulfate, the second storage tank is loaded with 1 wt% to 70 wt% of hydrogen peroxide, and the third storage tank is loaded with benzoyl chloride.

[0040] Furthermore, the concentration of the hydrogen peroxide solution is in the range of 5wt% to 30wt%, preferably 8wt% to 30wt%.

[0041] Furthermore, the molar ratio of sodium carbonate, hydrogen peroxide and benzoyl chloride in the sodium carbonate aqueous solution is (0.5-2):(0.3-1.5):1.

[0042] Furthermore, the temperature when transported to the pipeline reactor is 0-50°C, the pH is 8-9, and further, the temperature is 15-20°C.

[0043] Furthermore, before the material is transported from the storage tank to the pipeline reactor through the automatic sampler, it is first transported to the mixer through the automatic sampler for uniform mixing.

[0044] Furthermore, the temperature when conveyed to the mixer is 0 to 50°C, and further, 15 to 20°C.

[0045] Furthermore, the materials are mixed in the mixer at a temperature of 0 to 50° C. for a time of 0 to 60 min; further, the temperature is 15 to 20° C. for a time of 10 to 30 min.

[0046] Furthermore, the reaction temperature of the material in the pipeline reactor is 0-50°C, and the time is 30-180 min; further, the temperature is 15-20°C, and the time is 100-150 min, preferably 120-140 min.

[0047] Furthermore, the pipeline continuous production device is used to produce benzoyl peroxide with a yield range of 30% to 100%. By adjusting parameters, preferably the molar ratio of sodium carbonate, hydrogen peroxide and benzoyl chloride is 1:0.7:1, preferably a sodium carbonate aqueous solution of 15wt% sodium dodecyl sulfate, preferably a mixing time of 15min in the mixer, preferably a reaction time of 2h in the pipeline reactor, preferably a temperature of 15-20°C for the mixer and the pipeline reactor, the yield can reach more than 80%.

[0048] Compared with the prior art, the present invention has the following advantages:

[0049] (1) The prior art uses batch reaction to produce benzoyl peroxide, and the present invention provides a pipeline continuous reaction to produce benzoyl peroxide technology. The two production technologies have obvious differences in chemical reaction thermodynamics and chemical reaction kinetics. Batch reaction technology includes steps such as mixing, reaction, and separation, so the changes in the temperature, pressure, and substance concentration of the system have a significant impact on the reaction. In the pipeline continuous reaction process, the raw materials and products continuously pass through the reactor, and the temperature and pressure of the system are relatively stable, so the material flow rate, residence time, and conversion rate have a more significant impact on the reaction.

[0050] (2) The present invention is a pipeline continuous reaction. It is a continuous process from adding raw materials, chemical reaction to product collection. Materials will not accumulate in the reaction system for a long time, and the temperature and pressure of the system are relatively stable. Therefore, compared with the prior art of producing benzoyl peroxide by batch reaction, the present invention can greatly reduce the explosion risk in the production process. Moreover, the production capacity of benzoyl peroxide produced by batch reaction technology has an upper limit, and blindly expanding the production capacity will increase the explosion risk of the production process. However, the pipeline continuous reaction technology of the present invention is a continuous process of feeding and discharging. As long as the feeding of materials is continuously maintained, the discharging of products can be continuously maintained, which is easy to expand the output and production capacity without increasing the risk of production. The technology of the present invention can fully guarantee the safety requirements of large-scale continuous production.

[0051] (3) The present invention has the advantages of simple process, safe operation, low production cost and high yield, and can obtain benzoyl peroxide that does not agglomerate, has uniform particle size and is easy to wash. The product has high purity and low impurity content, and can meet the needs of the high-end market.

[0052] (4) The present invention can realize fully automated continuous production without causing the problem of large amounts of chemical wastewater discharge in the production of traditional chemical raw materials. It is a green, safe and efficient automated production device. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 It is a structural schematic diagram of the pipeline continuous production device shown in Example 1;

[0054] Figure 2 This is a schematic diagram of the structure of the pipeline continuous production device shown in Example 2.

[0055] Description of the markings in the figure:

[0056] 1-storage tank, 11-first storage tank, 12-second storage tank, 13-third storage tank;

[0057] 2-automatic sampler, 21-first delivery pump, 22-second delivery pump, 23-third delivery pump;

[0058] 3-mixer, 31-reactor, 32-agitator, 33-first input port, 34-second input port, 35-third input port, 36-output port;

[0059] 4- pipeline reactor, 41- conveying pipe, 42- screw conveyor, 421- rotating shaft, 422- bearing, 423- rotating blade, 424- motor, 43- feed port, 44- discharge port;

[0060] 5-Pipeline. DETAILED DESCRIPTION

[0061] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. The present embodiment is implemented on the premise of technical solution of the present invention, and detailed implementation mode and specific operation process are provided, but protection scope of the present invention is not limited to the following embodiments. In the following embodiments or embodiments, if there is no special functional component or structure, it is shown that it is the conventional component or conventional structure adopted in this area to realize the corresponding function. Unless otherwise specified, the reagent, method, instrument and equipment used in the present invention are conventional reagents, methods, instruments and equipment in this area.

[0062] It should be noted that in the description of the present invention, the terms "upper", "lower", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0063] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0064] Example 1

[0065] See also Figure 1 A pipeline continuous production device for preparing benzoyl peroxide, comprising a storage tank 1, an automatic sampler 2, and a pipeline reactor 4 connected in sequence along the direction of material travel, wherein the pipeline reactor 4 comprises a delivery pipe 41 and a screw conveyor 42, the delivery pipe 41 is sleeved outside the screw conveyor 42 and is coaxial with the screw conveyor 42, a feed port 43 and a discharge port 44 are respectively arranged at both ends of the delivery pipe 41, the pipeline reactor 4 is tilted so that the height of the discharge port 44 is higher than the height of the feed port 43, and the storage tank 1, the automatic sampler 2, and the pipeline reactor 4 are connected by a pipeline 5.

[0066] In this embodiment, the material of the pipeline continuous production device that is in direct contact with the material is an acid-base-resistant and corrosion-resistant material, namely stainless steel. The connection parts of the storage tank 1, the automatic sampler 2 and the pipeline 5 are equipped with tightly connected joints to prevent liquid from leaking from the connection, wherein the automatic sampler 2 needs to achieve a leak-free performance.

[0067] In this embodiment, the storage tank 1 includes a first storage tank 11 loaded with a sodium carbonate aqueous solution containing sodium dodecyl sulfate, a second storage tank 12 loaded with hydrogen peroxide, and a third storage tank 13 loaded with benzoyl chloride.

[0068] In this embodiment, the automatic sampler 2 includes a first delivery pump 21 for delivering sodium carbonate aqueous solution of sodium dodecyl sulfate, a second delivery pump 22 for delivering hydrogen peroxide, and a third delivery pump 23 for delivering benzoyl chloride. The automatic sampler 2 can control the temperature, pressure and flow rate during material delivery, and can also independently control the delivery rate of each material, so that multiple materials can be added in molar ratio, mass ratio or volume ratio.

[0069] In this embodiment, the feed port 43 and the discharge port 44 are located on both sides of the conveying pipe 41, the feed port 43 opens upward, and the discharge port 44 opens downward. The automatic sampler 2 will convey the material to the feed port 43 of the pipeline reactor 4. The pipeline reactor 4 is tilted so that the height of the discharge port 44 is higher than the height of the feed port 43 to ensure that the reaction liquid stays in the pipeline reactor 4 for a sufficient time to generate products. The material is conveyed forward along the conveying pipe 41 under the push of the screw conveyor 42. The discharge port 44 should be tilted upward at an angle of 30° relative to the feed port 43. A sealing component is provided at the connection between the conveying pipe 41 and the screw conveyor 42 of the pipeline reactor 4.

[0070] In this embodiment, the screw conveyor 42 includes:

[0071] A motor 424 for providing power;

[0072] A bearing 422 for supporting function;

[0073] A rotating shaft 421 for rotation;

[0074] And the rotating blades 423 are responsible for driving the material to move.

[0075] In this embodiment, the conveying pipe 41 has a length of 2 m and a diameter of 30 cm. The screw conveyor has a length of 1.8 m and a diameter of 25 cm. The screw conveyor has a pitch of 5 cm and a rotation speed of 50 rpm.

[0076] Example 2

[0077] See also Figure 2A pipeline continuous production device for preparing benzoyl peroxide, comprising a storage tank 1, an automatic sampler 2, and a pipeline reactor 4 connected in sequence along the material direction, wherein the pipeline reactor 4 comprises a delivery pipe 41 and a screw conveyor 42, the delivery pipe 41 is sleeved outside the screw conveyor 42 and is coaxial with the screw conveyor 42, a feed port 43 and a discharge port 44 are respectively arranged at both ends of the delivery pipe 41, the pipeline reactor 4 is tilted so that the height of the discharge port 44 is higher than the height of the feed port 43, and the storage tank 1, the automatic sampler 2, and the pipeline reactor 4 are connected by a pipeline 5.

[0078] In this embodiment, the material of the pipeline continuous production device that is in direct contact with the material is an acid-resistant, alkali-resistant, and corrosion-resistant material, which is tetrafluoroethylene. The connection parts of the storage tank 1, the automatic sampler 2, and the pipeline 5 are equipped with tightly connected joints to prevent liquid from leaking from the connection, wherein the automatic sampler 2 needs to achieve a leak-free performance.

[0079] In this embodiment, the storage tank 1 includes a first storage tank 11 loaded with a sodium carbonate aqueous solution containing sodium dodecyl sulfate, a second storage tank 12 loaded with hydrogen peroxide, and a third storage tank 13 loaded with benzoyl chloride.

[0080] In this embodiment, the automatic sampler 2 includes a first delivery pump 21 for delivering sodium carbonate aqueous solution of sodium dodecyl sulfate, a second delivery pump 22 for delivering hydrogen peroxide, and a third delivery pump 23 for delivering benzoyl chloride. The automatic sampler 2 can control the temperature, pressure and flow rate during material delivery, and can also independently control the delivery rate of each material, so that multiple materials can be added in molar ratio, mass ratio or volume ratio.

[0081] In this embodiment, the feed port 43 and the discharge port 44 are located on both sides of the conveying pipe 41, the feed port 43 opens upward, and the discharge port 44 opens downward. The material flows into the feed port of the pipeline reactor 4, and the material flows out from the discharge port 44 under the push of the screw conveyor (42) in the pipeline reactor 4. The pipeline reactor 4 is tilted so that the height of the discharge port 44 is higher than the height of the feed port 43 to ensure that the pipeline reactor 4 is filled with reaction liquid, and the material is transported forward along the conveying pipe 41 under the push of the screw conveyor 42. The discharge port 44 should be tilted upward at an angle of 30° relative to the feed port 43. A sealing component is provided at the connection between the conveying pipe 41 and the screw conveyor 42 of the pipeline reactor 4.

[0082] In this embodiment, the screw conveyor 42 includes:

[0083] A motor 424 for providing power;

[0084] A bearing 422 for supporting function;

[0085] A rotating shaft 421 for rotation;

[0086] And the rotating blades 423 are responsible for driving the material to move.

[0087] In this embodiment, the conveying pipe 41 has a length of 2 m and a diameter of 30 cm. The screw conveyor has a length of 1.8 m and a diameter of 25 cm. The screw conveyor has a pitch of 5 cm and a rotation speed of 50 rpm.

[0088] In this embodiment, a mixer 3 is provided between the automatic sampler 2 and the pipeline reactor 4, which comprises:

[0089] Reactor 31;

[0090] An agitator 32 is disposed inside the reaction kettle 31, and the agitator 32 is provided with a plurality of agitating blades in a vertical direction, which are distributed at the upper, middle and lower positions of the reaction kettle 31;

[0091] A first input port 33, a second input port 34, and a third input port 35 directly connected to the bottom of the reactor, and the first input port 33, the second input port 34, and the third input port 35 are connected to the automatic sample injector 2;

[0092] The output port 36 is connected to the feed port 43 of the pipeline reactor 4.

[0093] In this embodiment, the volume of the reaction kettle 31 is 2L.

[0094] In this embodiment, the output port 34 is arranged at the upper end of the side of the reactor 31. As the material is continuously added, the liquid level in the reactor 31 rises. When the liquid level reaches the output port 34, the uniformly mixed material overflows from the output port 34; the overflowed material enters the pipeline reactor 4. The mixing time of the material can be controlled by controlling the volume and feeding speed of the mixer 3. Before a large amount of sediment appears, the material should be discharged from the output port 34 and enter the pipeline reactor 4.

[0095] Compared with Example 1, most of them are the same, except that a mixer 3 is added between the automatic sampler 2 and the pipeline reactor 4. When benzoyl peroxide is prepared under the same conditions, Example 2 can increase the yield of benzoyl peroxide.

[0096] Example 3

[0097] A pipeline continuous production device for preparing benzoyl peroxide comprises a storage tank 1, an automatic sampler 2, and a pipeline reactor 4 which are sequentially connected along a material direction, wherein the pipeline reactor 4 comprises a delivery pipe 41 and a screw conveyor 42, the delivery pipe 41 is sleeved outside the screw conveyor 42 and is coaxial with the screw conveyor 42, a feed port 43 and a discharge port 44 are respectively arranged in different directions at two ends of the delivery pipe 41, the pipeline reactor 4 is tilted so that the height of the discharge port 44 is higher than that of the feed port 43, and the storage tank 1, the automatic sampler 2, and the pipeline reactor 4 are connected via a pipeline 5.

[0098] In this embodiment, the material of the pipeline continuous production device that is in direct contact with the material is an acid-base-resistant and corrosion-resistant material, namely stainless steel. The connection parts of the storage tank 1, the automatic sampler 2 and the pipeline 5 are equipped with tightly connected joints to prevent liquid from leaking from the connection, wherein the automatic sampler 2 needs to achieve a leak-free performance.

[0099] In this embodiment, the storage tank 1 includes a first storage tank 11 loaded with a sodium carbonate aqueous solution containing sodium dodecyl sulfate, a second storage tank 12 loaded with hydrogen peroxide, and a third storage tank 13 loaded with benzoyl chloride.

[0100] In this embodiment, the automatic sampler 2 includes a first delivery pump 21 for delivering sodium carbonate aqueous solution of sodium dodecyl sulfate, a second delivery pump 22 for delivering hydrogen peroxide, and a third delivery pump 23 for delivering benzoyl chloride. The automatic sampler 2 can control the temperature, pressure and flow rate during material delivery, and can also independently control the delivery rate of each material, so that multiple materials can be added in molar ratio, mass ratio or volume ratio.

[0101] In this embodiment, the feed port 43 and the discharge port 44 are located on both sides of the conveying pipe 41, the feed port 43 opens upward, and the discharge port 44 opens downward. The material flows into the feed port of the pipeline reactor 4, and the material flows out from the discharge port 44 under the push of the screw conveyor 42 in the pipeline reactor 4. The pipeline reactor 4 is tilted so that the height of the discharge port 44 is higher than the height of the feed port 43 to ensure that the pipeline reactor 4 is filled with reaction liquid, and the material is transported forward along the conveying pipe 41 under the push of the screw conveyor 42. The discharge port 44 should be tilted upward at an angle of 30° relative to the feed port 43. A sealing assembly is provided at the connection between the conveying pipe 41 and the screw conveyor 42 of the pipeline reactor 4. The outside of the conveying pipe 41 of the pipeline reactor 4 is provided with a first jacket that can be heated or cooled, and the outside of the first jacket is provided with a first insulation layer, which is foamed silica gel. Water of different temperatures is added into the first jacket to control the temperature of the pipeline reactor 4 , and the first thermal insulation layer is used to prevent heat loss or external heat intrusion, thereby controlling the temperature of the pipeline reactor 4 .

[0102] In this embodiment, the screw conveyor 42 includes:

[0103] A motor 424 for providing power;

[0104] A bearing 422 for supporting function;

[0105] A rotating shaft 421 for rotation;

[0106] And the rotating blades 423 are responsible for driving the material to move.

[0107] In this embodiment, the conveying pipe 41 has a length of 2 m and a diameter of 30 cm. The screw conveyor has a length of 1.8 m and a diameter of 25 cm. The screw conveyor has a pitch of 5 cm and a rotation speed of 50 rpm.

[0108] In this embodiment, a mixer 3 is provided between the automatic sampler 2 and the pipeline reactor 4, which comprises:

[0109] Reactor 31;

[0110] An agitator 32 is disposed inside the reaction kettle 31, and the agitator 32 is provided with a plurality of agitating blades in a vertical direction, which are distributed at the upper, middle and lower positions of the reaction kettle 31;

[0111] A first input port 33, a second input port 34, and a third input port 35 directly connected to the bottom of the reactor, and the first input port 33, the second input port 34, and the third input port 35 are connected to the automatic sample injector 2;

[0112] The output port 36 is connected to the feed port 43 of the pipeline reactor 4.

[0113] In this embodiment, the volume of the reaction kettle 31 is 2L.

[0114] In this embodiment, the output port 34 is arranged at the upper end of the side of the reactor 31. As the material is continuously added, the liquid level in the reactor 31 rises. When the liquid level reaches the output port 34, the uniformly mixed material overflows from the output port 34; the overflowed material enters the pipeline reactor 4. The mixing time of the material can be controlled by controlling the volume and feeding speed of the mixer 3. Before a large amount of sediment appears, the material should be discharged from the output port 34 and enter the pipeline reactor 4. The outside of the reactor 31 is provided with a second jacket that can be heated or cooled, and a second insulation layer is arranged outside the second jacket, which is asbestos. The second jacket is placed with a heating wire for controlling the temperature of the reactor 31. The second insulation layer is used to prevent heat loss or external heat intrusion, thereby controlling the temperature of the reactor 31.

[0115] Compared with Example 2, most of them are the same, except that a first jacket and a first insulation layer are added outside the pipeline reactor 4, and a second jacket and a second insulation layer are added outside the reactor 31.

[0116] Example 4

[0117] A pipeline continuous production method for preparing benzoyl peroxide, which is implemented using the device shown in Example 1, and the method comprises the following steps:

[0118] A1, the automatic sampler 2 transports the material loaded in the storage tank 1 to the pipeline reactor 4 according to a certain molar ratio;

[0119] A2, while the material is reacting in the pipeline reactor 4, it is transported to the discharge port 44 by the screw conveyor 42 to obtain a crude product;

[0120] A3. The obtained crude product is filtered, washed and dried to obtain the final product benzoyl peroxide.

[0121] In this embodiment, the first storage tank 11 is loaded with a sodium carbonate aqueous solution containing sodium dodecyl sulfate, wherein the sodium carbonate aqueous solution containing sodium dodecyl sulfate is first prepared with a 15wt% sodium dodecyl sulfate aqueous solution, and then 1mL of the 15wt% sodium dodecyl sulfate aqueous solution is added to 200mL of the sodium carbonate aqueous solution, the second storage tank 12 is loaded with 30wt% hydrogen peroxide, and the third storage tank 13 is loaded with benzoyl chloride.

[0122] In this embodiment, the molar ratio of sodium carbonate, hydrogen peroxide and benzoyl chloride in the sodium carbonate aqueous solution is 1.04:0.71:1. The temperature when transported to the pipeline reactor 4 is 17°C, the pH is 8.5, and the total duration of step A2 is 90 minutes.

[0123] In this embodiment, the delivery pump 21 of the automatic sampler 2 delivers 1400mL of sodium carbonate aqueous solution containing sodium dodecyl sulfate, totaling 1.45mol of sodium carbonate, through the pipeline 5, the delivery pump 22 delivers 98mL of 30% hydrogen peroxide, totaling 0.98mol of hydrogen peroxide, through the pipeline 5, and the delivery pump 23 delivers 196g of benzoyl chloride, totaling 1.39mol of benzoyl chloride, through the pipeline. The three delivery pumps deliver the sodium carbonate aqueous solution containing sodium dodecyl sulfate, hydrogen peroxide, and benzoyl chloride to the pipeline reactor 4 according to the above molar ratio. The temperature is controlled between 15 and 20°C during delivery, and the pH is controlled between 8 and 9. The temperature of the reaction of the material in the pipeline reactor 4 is controlled at 15 to 20°C, and the material is delivered to the discharge port 44 by the screw conveyor 42 to obtain a crude product, and the total time from material input to output is 90min. The crude product is collected at the discharge port 44, filtered, and the filter cake is washed with purified water 700mL×3 times, and drained to obtain the final product.

[0124] The results of the product detection by high performance liquid chromatography (HPLC) are shown in Table 1.

[0125] Table 1 HPLC content analysis results of Example 4

[0126]

[0127]

[0128] As can be seen from Table 1 above, the quality of the three batches of products produced this time is stable, the average yield of benzoyl peroxide is 90.03%, the average content of benzoyl peroxide is 99.7%, the average content of water is 28.5%, the average content of benzoic acid is 0.21%, the average content of benzoyl chloride is 0.047%, the average content of unknown impurities is 0.04%, and ethyl benzoate is not found.

[0129] Example 5

[0130] The material amount of Example 4 was enlarged for production.

[0131] The delivery pump 21 of the automatic sampler 2 delivers 14L of sodium carbonate aqueous solution containing sodium dodecyl sulfate, totaling 14.5mol of sodium carbonate, through the pipeline 5, the delivery pump 22 delivers 0.98L of 30% hydrogen peroxide, totaling 9.8mol of hydrogen peroxide, through the pipeline 5, and the delivery pump 23 delivers 1960g of benzoyl chloride, totaling 13.9mol of benzoyl chloride, through the pipeline. The three delivery pumps deliver the sodium carbonate aqueous solution containing sodium dodecyl sulfate, hydrogen peroxide, and benzoyl chloride to the pipeline reactor 4 according to the above molar ratio. The temperature is controlled between 15 and 20°C during delivery, and the pH is controlled between 8 and 9. The temperature of the reaction of the material in the pipeline reactor 4 is controlled between 15 and 20°C, and the material is delivered to the discharge port 44 by the screw conveyor 42 to obtain a crude product. The total time from material input to output is 10h. The crude product is collected at the discharge port 44, filtered, and the filter cake is washed with purified water 7.5L×3 times, and drained to obtain the final product.

[0132] Two batches were repeated, and the results of HPLC detection of the product are shown in Table 2.

[0133] Table 2 HPLC content analysis results of Example 5

[0134]

[0135] As shown in Table 2 above, the quality of the two batches of products produced this time is stable, the average yield of benzoyl peroxide is 82.65%, the average content of benzoyl peroxide is 99.65%, the average content of water is 25.2%, the average content of benzoic acid is 0.255%, and the average content of unknown impurities is 0.095%. Therefore, when the material amount is enlarged, the purity of benzoyl peroxide produced by the device is still as high as 99.65%, and the yield is also 82.65%.

[0136] Example 6

[0137] A pipeline continuous production method for preparing benzoyl peroxide, which is implemented using the device shown in Example 2, and the method comprises the following steps:

[0138] B1, the automatic sampler 2 transports the material loaded in the storage tank 1 to the mixer 3 according to a certain molar ratio;

[0139] B2, the materials are mixed uniformly in the mixer 3 and then transported to the pipeline reactor 4;

[0140] B3, while the material is reacting in the pipeline reactor 4, it is transported to the discharge port 44 by the screw conveyor 42 to obtain a crude product;

[0141] B4. The obtained crude product is filtered, washed and dried to obtain the final product benzoyl peroxide.

[0142] In this embodiment, the temperature when transported to the mixer 3 is between 15 and 20°C, the material is mixed in the mixer 3 at a temperature between 15 and 20°C for 30 minutes, and the reaction temperature of the material in the pipeline reactor 4 is between 15 and 20°C for 120 minutes.

[0143] The delivery pump 21 of the automatic sampler 2 delivers 21L of sodium carbonate aqueous solution containing 15% sodium dodecyl sulfate, totaling 21.75mol of sodium carbonate, through the pipeline 5, the delivery pump 22 delivers 1.47L of 30% hydrogen peroxide, totaling 14.7mol of hydrogen peroxide, through the pipeline 5, and the delivery pump 23 delivers 2940g of benzoyl chloride, totaling 20.85mol of benzoyl chloride, through the pipeline. The three delivery pumps deliver the sodium carbonate aqueous solution containing sodium dodecyl sulfate, hydrogen peroxide, and benzoyl chloride to the pipeline reactor 4 according to the above molar ratio. The temperature is controlled to be 17°C during delivery, and the pH is controlled to be 8.5. The temperature of the reaction of the material in the pipeline reactor 4 is controlled at 17°C, and the material is delivered to the discharge port 44 by the screw conveyor 42 to obtain a crude product. The total time from material input to output is 10h. The crude product is collected at the discharge port 44, filtered, and the filter cake is washed with purified water 8.0L×3 times, and drained to obtain the final product.

[0144] Two batches were repeated, and the results of HPLC detection of the products are shown in Table 3.

[0145] Table 3 HPLC content analysis results of Example 6

[0146]

[0147] As can be seen from Table 3 above, the quality of the two batches of products produced this time is stable, the average yield of benzoyl peroxide is 89.85%, the average content of benzoyl peroxide is 99.6%, the average content of water is 23.9%, the average content of benzoic acid is 0.335%, and the average content of unknown impurities is 0.065%.

[0148] The device of Example 6 has a mixer 3 more than the device of Example 5. The yield of Example 6 is increased by 7.2% over that of Example 5, indicating that the provision of the mixer 3 can further increase the yield of the benzoyl peroxide preparation process.

[0149] Compared with Example 4, Example 5 and Example 6 are scaled-up production. It can be seen that the pipeline continuous production method can effectively increase output and production capacity. The obtained product has a very high purity and can fully meet the needs of the high-end market.

[0150] Comparative Example 1

[0151] The batch reaction was carried out with the material feed ratio of Example 4, and the molar ratio of anhydrous sodium carbonate, hydrogen peroxide and benzoyl chloride was 1.04:0.71:1.

[0152] 5.5 g of anhydrous sodium carbonate was dissolved in 50 mL of purified water. 3.5 mL of 30% hydrogen peroxide and 0.25 mL of 15% sodium dodecyl sulfate were added under an ice-water bath at about 15°C. 7.0 g of benzoyl chloride was added dropwise while maintaining the temperature at about 15°C. After the addition was completed, the mixture was mechanically stirred for 2 h at 15-20°C. White granular crystals were generated during the reaction. The crystals were filtered and the filter cake was washed with 30 mL of purified water for 3 times to obtain a white granular product. The HPLC test results of the product are shown in Table 4.

[0153] Table 4 HPLC content analysis results of Comparative Example 1

[0154]

[0155] Comparative Example 1 is a batch reaction production method, and the purity of the obtained benzoyl peroxide is 99.37%. The batch reaction production method is limited by the volume of the reaction device, and it is not easy to expand the output and production capacity. Moreover, the purity of the benzoyl peroxide obtained by the batch reaction is not as good as that of the pipeline continuous reaction method, and the content of unknown impurities in the batch reaction is much higher than that of the pipeline continuous reaction method.

[0156] Therefore, the pipeline continuous production device can obtain high-purity benzoyl peroxide, which can meet the needs of the high-end market. For example, the quality standards of benzoyl peroxide raw materials included in the Chinese, American and European Pharmacopoeias are: benzoyl peroxide (water-containing) content is 70.0-77.0%, water content ≥20.0%; impurity A (benzaldehyde) content ≤0.25%, impurity C (ethyl benzoate) content ≤0.25%, impurity B (benzoic acid) ≤1.5%; maximum unknown single impurity ≤0.1%.

[0157] The pipeline continuous production device can realize fully automated continuous production and is a green, safe and efficient automated production device. It can effectively improve the purity, yield, output and production capacity of benzoyl peroxide, improve the safety of the production process and reduce production costs.

[0158] Although the present invention has been described in detail above by means of general description, specific implementation methods and tests, it is obvious to those skilled in the art that some modifications or improvements may be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A pipeline continuous production device for preparing benzoyl peroxide, characterized in that: The invention comprises a material storage tank (1), an automatic sampler (2), and a pipeline reactor (4) which are sequentially connected along the material direction, wherein the pipeline reactor (4) comprises a conveying pipe (41) and a screw conveyor (42), the conveying pipe (41) is sleeved outside the screw conveyor (42) and is coaxial with the screw conveyor (42), a feed port (43) and a discharge port (44) are respectively arranged at two ends of the conveying pipe (41), the pipeline reactor (4) is placed at an angle so that the height of the discharge port (44) is higher than the height of the feed port (43), and the material storage tank (1), the automatic sampler (2), and the pipeline reactor (4) are connected via a pipeline (5).

2. A pipeline continuous production device for preparing benzoyl peroxide according to claim 1, characterized in that: The storage tank (1) comprises a first storage tank (11) loaded with a sodium carbonate aqueous solution containing sodium lauryl sulfate, a second storage tank (12) loaded with hydrogen peroxide, and a third storage tank (13) loaded with benzoyl chloride.

3. A pipeline continuous production device for preparing benzoyl peroxide according to claim 1, characterized in that: The automatic sampler (2) comprises a first delivery pump (21) for delivering sodium carbonate aqueous solution of sodium dodecyl sulfate, a second delivery pump (22) for delivering hydrogen peroxide, and a third delivery pump (23) for delivering benzoyl chloride.

4. A pipeline continuous production device for preparing benzoyl peroxide according to claim 1, characterized in that: The feed port (43) and the discharge port (44) are located on the same side or both sides of the conveying pipe (41), and open upward or downward.

5. A pipeline continuous production device for preparing benzoyl peroxide according to claim 1, characterized in that: The outside of the delivery pipe (41) of the pipeline reactor (4) is provided with a first jacket that can be heated or cooled, and the outside of the first jacket is provided with a first insulation layer.

6. A pipeline continuous production device for preparing benzoyl peroxide according to claim 1, characterized in that: The screw conveyor (42) comprises: A motor (424) for providing power; A bearing (422) for supporting; A rotating shaft (421) for rotation; And the rotating blades (423) are responsible for driving the material to move.

7. A pipeline continuous production device for preparing benzoyl peroxide according to claim 1, characterized in that: A mixer (3) is provided between the automatic sampler (2) and the pipeline reactor (4), and comprises: Reactor (31); An agitator (32) is arranged inside the reaction kettle (31), wherein the agitator (32) is provided with a plurality of agitating blades in a vertical direction and distributed at the upper, middle and lower positions of the reaction kettle (31); A first input port (33), a second input port (34), and a third input port (35) directly connected to the bottom of the reaction kettle, and the first input port (33), the second input port (34), and the third input port (35) are connected to the automatic sample injector (2); An output port (36) connected to the feed port (43) of the pipeline reactor (4).

8. A pipeline continuous production device for preparing benzoyl peroxide according to claim 7, characterized in that: The outside of the reaction kettle (31) is provided with a second jacket that can be heated or cooled, and a second heat insulating layer is arranged outside the second jacket.

9. A pipeline continuous production method for preparing benzoyl peroxide, which is implemented by using the device according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: A1, the automatic sampler (2) transports the material loaded in the storage tank (1) to the pipeline reactor (4) according to a certain molar ratio; A2, while the material is reacting in the pipeline reactor (4), it is transported to the discharge port (44) by the screw conveyor (42) to obtain a crude product; A3. The obtained crude product is filtered, washed and dried to obtain the final product benzoyl peroxide.

10. A pipeline continuous production method for preparing benzoyl peroxide according to claim 9, characterized in that: Before the material is transported from the storage tank (1) to the pipeline reactor (4) through the automatic sampler (2), it is first transported to the mixer (3) through the automatic sampler (2) for uniform mixing.

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