A device and method for synthesizing 2,4-dimethyl-6-tert-butylphenol

Abstract

The present application relates to the technical field of 2,4-dimethyl-6-tert-butyl phenol preparation, and particularly relates to a synthesis device and method of 2,4-dimethyl-6-tert-butyl phenol. The synthesis device comprises a closed tank body, a filter plate allowing only hydrogen to pass through is arranged in the tank body, a hydrogen cavity is arranged above the filter plate, and a reaction cavity is arranged below the filter plate; the reaction cavity is provided with a hydrogen pipe communicated with the hydrogen cavity and a hollow stirring shaft in sealing rotary connection with the hydrogen pipe; a motor is connected to the lower end of the stirring shaft, and stirring blades and nozzles are arranged on the outer side wall. The synthesis method comprises the following steps: adding antioxidant 2246, methanol, an alkali catalyst and a catalyst aid into the synthesis device, stirring and performing a cracking reaction under a reaction temperature and a reaction pressure, filtering and purifying the product after the reaction is completed. The present application cracks the antioxidant 2246, matches the synthesis device with high adaptability, and finally efficiently prepares liquid 2,4-dimethyl-6-tert-butyl phenol with a yield of more than 90% and a purity of more than 99%.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of 2,4-dimethyl-6-tert-butyl phenol preparation, and particularly relates to a synthesis device and method of 2,4-dimethyl-6-tert-butyl phenol. BACKGROUND

[0002] 2,4-dimethyl-6-tert-butyl phenol is a substance capable of rapidly reacting with free radicals to terminate chain reaction, is a new type of high-temperature resistant aviation fuel antioxidant, an acrylic acid polymerization inhibitor, is an intermediate of various high-molecular antioxidants, and is also a very important pharmaceutical intermediate. In the prior art, 2,4-dimethyl-6-tert-butyl phenol is added to methyl methacrylate as a polymerization inhibitor, which can effectively prevent the polymerization of the methyl methacrylate product during storage and transportation.

[0003] At present, the preparation method of 2,4-dimethyl-6-tert-butyl phenol mainly uses 2,4-dimethyl phenol and isobutene as raw materials, and concentrated sulfuric acid as a catalyst for alkylation reaction. Wang Haoyang et al. passed isobutene into 2,4-dimethyl phenol at 90℃ for 4h to obtain the target product 2,4-dimethyl-6-tert-butyl phenol, with a purity of 99% and a yield of more than 95%. However, 2,4-dimethyl phenol is relatively expensive, which can be derived from phenol methylation. This reaction has the problems of low selectivity and difficult separation. It can also be derived from m-xylene sulfonation method. Although this reaction uses low-cost raw materials, it involves multiple dangerous reactions and is not suitable for industrialization.

[0004] Antioxidant 2246 (2,2'-methylenebis[4-methyl-6-tert-butyl phenol]) is a common industrial antioxidant, and the raw material is easy to obtain. Its molecular structure contains the key skeleton of the target product, making it possible to obtain 2,4-dimethyl-6-tert-butyl phenol through a cracking reaction. The cracking reaction requires a high-pressure reactor, and the high-pressure reactor in the prior art is not highly adaptable to the preparation of 2,4-dimethyl-6-tert-butyl phenol by cracking of antioxidant 2246.

[0005] In summary, it is necessary to consider using antioxidant 2246 as raw material, adopting a reaction system with mild reaction conditions, and matching a suitable synthesis device to obtain 2,4-dimethyl-6-tert-butyl phenol with high yield and high purity. SUMMARY

[0006] To solve at least one of the above problems, the application provides a device for synthesizing 2,4-dimethyl-6-tert-butyl phenol, which comprises a closed tank body, a filter plate allowing only hydrogen to pass through is horizontally arranged in the tank body, a hydrogen cavity is arranged above the filter plate, and a reaction cavity is arranged below the filter plate; the reaction cavity is provided with a hydrogen pipe penetrating through and fixed at the center of the filter plate and a hollow stirring shaft with an open top in sealing and rotating connection with the hydrogen pipe; the lower end of the stirring shaft is connected with a motor, the outer side wall is provided with stirring blades and a one-way gas nozzle in communication with the hollow of the stirring shaft.

[0007] Preferably, the top of the tank body is provided with a feeding pipe and an exhaust pipe in communication with the reaction cavity, the bottom is provided with a discharging pipe and a temperature sensor, the outer side wall is provided with a heating jacket, the exhaust pipe is provided with a pressure sensor and an electric valve, and the feeding pipe and the discharging pipe are respectively provided with on-off valves.

[0008] Preferably, the hydrogen pipe is provided with a pressurizing mechanism, the pressurizing mechanism comprises an annular piston sealingly and dampingly lifting along the hydrogen pipe, a lifting pipe capable of sealingly and vertically sliding a certain distance relative to the piston is arranged at the center of the piston, the top of the lifting pipe is sealed, the outer side wall of the lifting pipe is provided with a side hole capable of being blocked by the piston, the bottom of the lifting pipe extends downward to above the nozzle and is provided with a ring-shaped flange sealingly and rotatably abutting against the inner side wall of the stirring shaft, when the lifting pipe moves upward relative to the piston, the side hole can be unblocked, and a cam mechanism connected with the stirring shaft and the lifting pipe can drive the lifting pipe to lift.

[0009] Preferably, the inner side wall of the hydrogen pipe is vertically provided with a first guide groove, the outer side wall of the piston is provided with a first sliding block matched with the first guide groove, the inner side wall of the piston is provided with a second sliding block, the top of the lifting pipe is provided with a sealing cover, and the side wall of the lifting pipe is provided with a second guide groove for the second sliding block to vertically slide.

[0010] Preferably, the stirring shaft comprises a main shaft arranged in spaced apart relationship with the hydrogen pipe, the main shaft and the outer side wall of the hydrogen pipe are vertically and sealingly slidably provided with a lifting sleeve, the lifting sleeve can rotate relative to the hydrogen pipe, the lower end of the lifting sleeve is connected with the stirring blades through a connecting rod, and the inner side wall of the lifting sleeve is fixedly provided with a lifting ring, the stirring blades can vertically and directionally slide along the main shaft, and the outer side wall of the lifting pipe is provided with an upper pushing rod capable of pushing the lifting ring to descend and a lower pushing rod capable of pushing the lifting ring to ascend.

[0011] Preferably, the stirring blades comprise a shaft sleeve, a plurality of blades are circumferentially and equidistantly arranged on the outer side wall of the shaft sleeve, and a groove is vertically arranged on the inner side wall of the shaft sleeve, a sliding track matched with the groove is vertically arranged on the outer side wall of the main shaft, a limiting ring is arranged below the sliding track, first sealing rings are respectively arranged at the abutting positions of the lifting sleeve with the hydrogen pipe and the main shaft, a second sealing ring is arranged at the abutting position of the piston and the sealing cover, a third sealing ring is arranged at the abutting position of the piston and the lifting pipe, and a fourth sealing ring is arranged on the outer side wall of the ring-shaped flange.

[0012] The application provides a synthesis method of 2,4-dimethyl-6-tert-butyl phenol, and uses the synthesis device of the 2,4-dimethyl-6-tert-butyl phenol, and comprises the following steps:

[0013] S1, the antioxidant 2246, methanol, base catalyst and catalyst promoter are added into the reaction cavity of the synthesis device, the reaction is stirred at the reaction temperature and pressure, the generated hydrogen is introduced into the hydrogen cavity through the filter plate, then the hydrogen is sprayed into the reaction material from the hydrogen tube, the stirring shaft and the nozzle to promote the reaction, and the reaction completion liquid is obtained after the reaction is completed;

[0014] S2, the reaction completion liquid is cooled to room temperature, the catalyst promoter is removed by filtration, then the methanol is removed by reduced pressure distillation, and finally the organic phase is obtained by extracting with petroleum ether;

[0015] S3, the organic phase is sequentially subjected to water washing, anhydrous sodium sulfate drying and reduced pressure distillation, the crude product is obtained, the crude product is put into the rectifying column for reduced pressure rectification, the light components and heavy components are removed, and the 2,4-dimethyl-6-tert-butyl phenol is obtained.

[0016] Preferably, in step S1, the base catalyst is at least one of sodium hydroxide and potassium hydroxide; and the catalyst promoter is at least one of zinc oxide, copper oxide and aluminum oxide.

[0017] Preferably, in step S1, the mass of the base catalyst is 5-50wt% of the mass of the antioxidant 2246; the mass of the catalyst promoter is 1-10wt% of the mass of the antioxidant 2246; and the mass ratio of the methanol to the antioxidant 2246 is (2-15):1.

[0018] Preferably, in step S1, the reaction temperature is 200-300 DEG C, the reaction pressure is 7-20 MPa, and the reaction time is 3-10 h; in step S2, the temperature of the reduced pressure distillation is 25-45 DEG C, and the pressure is 50-80 KPa; in step S3, the temperature of the reduced pressure distillation is 25-45 DEG C, the pressure is 50-80 KPa, the column top temperature of the reduced pressure rectification is 160-200 DEG C, the column top temperature is 90-130 DEG C, the column temperature is 140-180 DEG C, and the pressure is 99 KPa.

[0019] Compared with the prior art, the application has the following beneficial technical effects:

[0020] 1, the filter plate for separating hydrogen is arranged in the tank body of the synthesis device, the upper portion of the filter plate is the hydrogen cavity, and the lower portion is the reaction cavity, the air in the hydrogen cavity is introduced into the hollow stirring shaft through the hydrogen tube, and then sprayed into the reaction material in the reaction cavity from the nozzle on the stirring shaft, so that the hydrogen content in the reaction material is improved, the cracking reaction of the antioxidant 2246 is promoted, and the reaction efficiency is greatly improved.

[0021] 2. The hydrogen pipe of the synthesis device is provided with a pressurizing mechanism, the piston, lifting pipe and cam mechanism of the pressurizing mechanism can be used in cooperation with the stirring shaft, so that the stirring shaft drives the piston and lifting pipe to lift during rotation, improves the strength of hydrogen ejected from the nozzle, improves the mixing uniformity of hydrogen and reactant, and thus improves the reaction efficiency;

[0022] 3. The stirring shaft of the synthesis device comprises a main shaft arranged at intervals with the hydrogen pipe and a lifting sleeve arranged in the main shaft and the hydrogen pipe, the lifting sleeve can lift with the lifting pipe of the pressurizing mechanism, drives the stirring blade connected with the lifting sleeve to vertically lift, improves the axial stirring range of the stirring blade, and thus improves the stirring effect;

[0023] 4. The synthesis method uses antioxidant 2246 as raw material, uses alkaline catalyst and cocatalyst for synergistic catalysis, and uses the hydrogen generated by the reaction to crack the antioxidant 2246, so that the reaction condition is mild, and high yield and high purity 2,4-dimethyl-6-tert-butyl phenol can be obtained;

[0024] In summary, the 2,4-dimethyl-6-tert-butyl phenol is prepared by cracking the antioxidant 2246, the synthesis device which can separate the hydrogen generated by the reaction and reintroduce the hydrogen into the reaction material to promote the cracking reaction is matched, and finally the liquid 2,4-dimethyl-6-tert-butyl phenol with a yield of more than 90% and a purity of more than 99% is efficiently prepared. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 It is a structure schematic view of the synthesis device of the present application;

[0026] Figure 2 It is a right view of the synthesis device;

[0027] Figure 3 It is Figure 2 A-A sectional view of

[0028] Figure 4 It is Figure 3 A local enlarged view of A in

[0029] Figure 5 It is Figure 3 A state schematic view when the lifting pipe in A reaches the highest point;

[0030] Figure 6 It is an explosion view of the pressurizing mechanism;

[0031] Figure 7 It is a partial solid sectional view of the stirring shaft;

[0032] Figure 8 It is a structure schematic view of the stirring blade.

[0033] REFERENCE SIGNS

[0034] 1. Tank body; 11. Hydrogen chamber; 12. Reaction chamber; 13. Feed pipe; 14. Gas outlet pipe; 15. Discharge pipe; 16. Heating jacket; 17. Pressure sensor; 18. Electric valve; 2. Filter plate; 3. Hydrogen pipe; 31. First guide groove; 4. Stirring shaft; 41. Main shaft; 411. Sliding rail; 412. Limiting ring; 42. Lifting sleeve; 421. First sealing ring; 43. Connecting rod; 44. Lifting ring; 5. Stirring blade; 51. Shaft sleeve; 511. Groove; 5 2. Blade; 6. Motor; 7. Nozzle; 8. Pressurizing mechanism; 81. Piston; 813. Second sealing ring; 811. First slider; 812. Second slider; 813. Second sealing ring; 814. Third sealing ring; 82. Lifting pipe; 821. Side hole; 822. Sealing cover; 823. Second guide groove; 824. Annular flange; 825. Fourth sealing ring; 83. Cam mechanism; 831. Cam groove; 832. Drive rod; 84. Upper push rod; 85. Lower push rod. Detailed Implementation

[0035] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0036] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below. Example 1

[0037] Combined with appendix Figures 1-8 This embodiment provides a synthesis apparatus for 2,4-dimethyl-6-tert-butylphenol, including a sealed tank 1. A filter plate 2, which allows only hydrogen gas to pass through, is horizontally arranged inside the tank 1. Above the filter plate 2 is a hydrogen chamber 11, and below it is a reaction chamber 12. The reaction chamber 12 is provided with a hydrogen pipe 3 that passes through and is fixed at the center of the filter plate 2, and a hollow stirring shaft 4 with a top opening that is sealed and rotatably connected to the hydrogen pipe 3. The lower end of the stirring shaft 4 is connected to a motor 6, and the outer wall is provided with stirring blades 5 and a one-way gas nozzle 7 that is hollowly connected to the stirring shaft 4.

[0038] In the technical solution, the reaction material in the reaction cavity 12 generates hydrogen and carbon dioxide during reaction, and therefore the inside of the reaction cavity 12 is naturally divided into a liquid phase zone and a gas phase zone from bottom to top. The filter plate 2 is used to separate the hydrogen and carbon dioxide in the gas phase zone. The filter plate 2 can adopt any suitable structure in the prior art, for example, can be a molecular sieve separation bed filled with a molecular sieve that only allows hydrogen to pass through, or can be a support plate with pores attached to a high molecular separation membrane that only allows hydrogen to pass through, etc. The hollow stirring shaft 4 with an open top refers to the top of the stirring shaft 4 being in an open state in communication with the hollow of the stirring shaft 4, while the bottom is in a closed state. In this embodiment, the lower end of the stirring shaft 4 is sealed and rotates to penetrate the bottom of the tank body 1 and is connected to the motor 6. A conventional connecting accessory such as a shaft coupling can be arranged between the rotating shaft of the motor 6 and the stirring shaft 4. This is a conventional setting and will not be described in detail. In use, the reaction material is added to the reaction cavity 12 and stirred under high temperature and high pressure. The hydrogen generated by the reaction enters the hydrogen cavity 11 through the filter plate 2. The hydrogen in the hydrogen cavity 11 enters the stirring shaft 4 through the hydrogen pipe 3. Since the reaction pressure in the tank body 1 is 7-20 MPa, the high-pressure hydrogen in the stirring shaft 4 is finally sprayed out of the nozzle 7 into the reaction material, thereby increasing the hydrogen content in the reaction material, promoting the cracking reaction of the reaction material, and greatly improving the reaction efficiency.

[0039] In a specific technical solution, the tank body 1 is provided with a feed pipe 13 and a gas outlet pipe 14 communicating with the reaction cavity 12 at the top, a discharge pipe 15 and a temperature sensor (not shown in the figure) at the bottom, and a heating jacket 16 on the outer side wall. The gas outlet pipe 14 is provided with a pressure sensor 17 and an electric valve 18. The feed pipe 13 and the discharge pipe 15 are respectively provided with on-off valves (not shown in the figure).

[0040] In the technical solution, the feed pipe 13 and the gas outlet pipe 14 are both sealed and penetrate the filter plate 2. In this embodiment, the tank body 1 includes a tank body and a cover body. The hydrogen cavity 11 is arranged in the cover body, and the filter plate 2 is fixed to the lower side wall of the cover body. In use, the temperature sensor, the pressure sensor 17, the electric valve 18, the on-off valve, and the motor 6 are connected to the controller. The controller is connected to a display for automatic control and adjustment.

[0041] In a specific technical solution, the hydrogen pipe 3 is provided with a pressurizing mechanism 8. The pressurizing mechanism 8 includes an annular piston 81 that is sealed and damped to ascend and descend along the hydrogen pipe 3. The center of the piston 81 is provided with a lifting pipe 82 that can be sealed and vertically slid a certain distance relative to the piston 81. The top of the lifting pipe 82 is sealed, and the outer side wall is provided with a side hole 821 that can be blocked by the piston 81. The bottom extends downward to above the nozzle 7 and is provided with a ring-shaped flange 824 that is sealed and rotates to abut the inner side wall of the stirring shaft 4. When the lifting pipe 82 moves upward relative to the piston 81, the side hole 821 can be unblocked. A cam mechanism 83 connected to the stirring shaft 4 and the lifting pipe 82 can drive the lifting pipe 82 to ascend and descend.

[0042] In the technical solution, the pressurizing mechanism 8 can improve the intensity of hydrogen gas sprayed from the nozzle 7 and improve the mixing uniformity of hydrogen gas and reactant, thereby improving the reaction efficiency; preferably, the outer side wall of the annular piston 81 is sprayed with a damping elastomer, so that damping and sealing effects can be achieved at the same time. Since there is damping force when the piston 81 is sealed and damped to rise and fall in the hydrogen gas pipe 3, the relative sliding between the piston 81 and the hydrogen gas pipe 3 lags behind the relative sliding between the piston 81 and the lifting pipe 82; the cam mechanism 83 is a conventional structure for converting rotary motion into linear motion, and the present application does not limit the specific structure thereof. In the embodiment, the cam mechanism 83 includes a cam groove 831 arranged below the outer side wall of the lifting pipe 82 and a driving rod 832 fixedly arranged above the inner side wall of the stirring shaft 4. The driving rod 832 rotates with the stirring shaft 4, and the cam groove 831 cooperating with the driving rod 832 and the lifting pipe 82 rise and fall with the rotation of the stirring shaft 4. Of course, the driving rod 832 can also be fixedly arranged on the outer side wall of the lifting pipe 82, and the cam groove 831 can be arranged on the inner side wall of the stirring shaft 4, and the driving principle is the same. In the initial state, the piston 81 blocks the side hole 821 on the lifting pipe 82. In use, the motor 6 is started, the stirring shaft 4 rotates, the cam mechanism 83 drives the lifting pipe 82 to rise and fall, when the lifting pipe 82 rises, the lifting pipe 82 moves upward relative to the piston 81, the side hole 821 is unblocked after being separated from the piston 81, the passage between the hydrogen gas cavity 11 and the inner cavity of the stirring shaft 4 is opened, high-pressure hydrogen gas enters the cavity formed by the annular flange 824 of the lifting pipe 82 and the main shaft 41, and is finally sprayed from the nozzle 7. When the lifting pipe 82 descends, the lifting pipe 82 moves downward relative to the piston 81, the side hole 821 is blocked by the piston 81, the passage between the hydrogen gas cavity 11 and the inner cavity of the stirring shaft 4 is closed, and as the lifting pipe 82 descends, the volume of the cavity formed by the annular flange 824 and the main shaft 41 continuously decreases, hydrogen gas is further compressed, and the intensity of hydrogen gas sprayed from the nozzle 7 is greatly improved.

[0043] In one specific technical solution, a first guide groove 31 is vertically arranged on the inner side wall of the hydrogen gas pipe 3, a first sliding block 811 cooperating with the first guide groove 31 is arranged on the outer side wall of the piston 81, a second sliding block 812 is arranged on the inner side wall, a sealing cover 822 is arranged on the top of the lifting pipe 82, and a second guide groove 823 for vertical sliding of the second sliding block 812 is arranged on the side wall.

[0044] In the technical solution, the first guide groove 31 and the first sliding block 811 are in sliding fit, so that the piston 81 can vertically ascend and descend along the hydrogen pipe 3 without circumferential sliding rotation; the second sliding block 812 and the second guide groove 823 are in sliding fit, so that the lifting pipe 82 can vertically ascend and descend along the piston 81 for a distance without circumferential sliding rotation, and the axial length of the second guide groove 823 determines the maximum distance that the lifting pipe 82 can relatively move with the piston 81, so the axial length of the second guide groove 823 is determined according to the vertical displacement of the lifting pipe 82 when the side hole 821 is blocked and unblocked.

[0045] In a specific technical solution, the stirring shaft 4 comprises a main shaft 41 which is arranged in parallel with the hydrogen pipe 3, the main shaft 41 and the outer side wall of the hydrogen pipe 3 are vertically and sealingly slidably provided with a lifting sleeve 42, the lifting sleeve 42 can rotate relative to the hydrogen pipe 3, a lifting ring 44 is fixedly arranged on the inner side wall of the lifting sleeve 42, and the stirring blade 5 is connected to the lower part of the lifting sleeve 42 through a connecting rod 43, the stirring blade 5 can vertically and directionally slide along the main shaft 41, and the outer side wall of the lifting pipe 82 is provided with an upper pushing rod 84 which can push the lifting ring 44 to descend and a lower pushing rod 85 which can push the lifting ring 44 to ascend.

[0046] In the technical solution, during the lifting of the lifting pipe 82, the upper pushing rod 84 and the lower pushing rod 85 of the lifting pipe 82 can push the lifting ring 44, the lifting sleeve 42 connected with the lifting ring 44, and the stirring blade 5 connected with the lifting sleeve 42 to ascend and descend, so that the stirring blade 5 can vertically ascend and descend while rotating and stirring, the axial stirring range is improved, and the stirring effect is improved; the upper pushing rod 84 can push the lifting ring 44 to descend, which means that the upper pushing rod 84 is located above the lifting ring 44, and the lower pushing rod 85 can push the lifting ring 44 to ascend, which means that the lower pushing rod 85 is located below the lifting ring 44; during use, the motor 6 drives the main shaft 41 and the lifting sleeve 42 and the stirring blade 5 connected with the main shaft 41 to rotate, and the cam mechanism 83 drives the lifting pipe 82 to ascend and descend, when the lifting pipe 82 ascends, the lower pushing rod 85 on the lifting pipe 82 ascends to the lower end surface of the lifting ring 44 and pushes the lifting ring 44 and the lifting sleeve 42 connected with the lifting ring 44 to ascend to the highest point, at this moment, the stirring blade 5 ascends to the highest point with the lifting sleeve 42, when the lifting pipe 82 descends, the upper pushing rod 84 on the lifting pipe 82 descends to the upper end surface of the lifting ring 44 and pushes the lifting ring 44 and the lifting sleeve 42 connected with the lifting ring 44 to descend to the lowest point, at this moment, the stirring blade 5 descends to the lowest point with the lifting sleeve 42.

[0047] In one specific technical solution, the stirring blade 5 comprises a shaft sleeve 51, a plurality of blades 52 are equidistantly arranged on the outer wall of the shaft sleeve 51, a groove 511 is vertically arranged on the inner wall of the shaft sleeve 51, a sliding track 411 matched with the groove 511 is vertically arranged on the outer wall of the main shaft 41, a limiting ring 412 is arranged below the sliding track 411, a first sealing ring 421 is arranged at the joint of the lifting sleeve 42 and the hydrogen pipe 3 and the main shaft 41 respectively, a second sealing ring 813 is arranged at the joint of the piston 81 and the sealing cover 822, a third sealing ring 814 is arranged at the joint of the piston 81 and the lifting pipe 82, and a fourth sealing ring 825 is arranged on the outer wall of the annular flange 824.

[0048] The working principle and working process of the embodiment are as follows: the temperature sensor, the pressure sensor 17, the electric valve 18, the on-off valve, the motor 6 and other electric elements are connected with the controller, the controller is connected with the display, and automatic control adjustment is performed; the reactant is added into the reaction cavity 12 from the feeding pipe 13, and the reaction is stirred under high temperature and high pressure, the hydrogen generated by the reaction enters the hydrogen cavity 11 through the filter plate 2, the hydrogen in the hydrogen cavity 11 enters the stirring shaft 4 through the hydrogen pipe 3, because the reaction pressure in the tank body 1 is 7-20 MPa, the high-pressure hydrogen in the stirring shaft 4 is finally sprayed out of the nozzle 7 to the reactant, the pressurizing mechanism 8 in the hydrogen pipe 3 increases the spraying intensity of the hydrogen, when the stirring shaft 4 rotates, the cam mechanism 83 connected with the main shaft 41 of the stirring shaft 4 and the lifting pipe 82 of the pressurizing mechanism 8 drives the lifting pipe 82 to lift, when the lifting pipe 82 rises, the side hole 821 is unsealed after being separated from the piston 81, the passage between the hydrogen cavity 11 and the cavity in the stirring shaft 4 is opened, the high-pressure hydrogen enters the cavity formed by the annular flange 824 of the lifting pipe 82 and the main shaft 41, and is finally sprayed out of the nozzle 7, when the lifting pipe 82 descends, the side hole 821 is blocked by the piston 81, the passage between the hydrogen cavity 11 and the cavity in the stirring shaft 4 is closed, with the descending of the lifting pipe 82, the volume of the cavity formed by the annular flange 824 and the main shaft 41 continuously decreases, the hydrogen is further compressed, and the spraying intensity of the hydrogen out of the nozzle 7 is greatly improved; during the lifting of the lifting pipe 82, the upper push rod 84 and the lower push rod 85 of the lifting pipe 82 can push the lifting ring 44, the lifting sleeve 42 connected with the lifting ring 44, and the stirring blade 5 connected with the lifting sleeve 42 to lift, so that the stirring blade 5 can lift vertically while rotating and stirring, the axial stirring range is improved, and the stirring effect is improved. Embodiment 2

[0049] The embodiment provides a synthesis method of 2,4-dimethyl-6-tert-butyl phenol, and uses the synthesis device of 2,4-dimethyl-6-tert-butyl phenol in embodiment 1, and comprises the following steps.

[0050] S1, the antioxidant 2246, methanol, base catalyst and co-catalyst are added to the reaction cavity 12 of the synthesis device, the reaction is stirred at the reaction temperature and pressure, the hydrogen generated in the reaction is introduced into the hydrogen cavity 11 through the filter plate 2, and then the hydrogen is sprayed into the reaction material through the hydrogen pipe 3, the stirring shaft 4 and the nozzle 7 to promote the reaction, and the reaction is completed to obtain a reaction completion liquid;

[0051] S2, the reaction completion liquid is cooled to room temperature, the co-catalyst is removed by filtration, then the methanol is removed by vacuum distillation, and finally the organic phase is obtained by extraction with petroleum ether;

[0052] S3, the organic phase is sequentially subjected to water washing, anhydrous sodium sulfate drying and vacuum distillation to obtain a crude product, the crude product is placed in a rectifying column for vacuum rectification, and 2,4-dimethyl-6-tert-butyl phenol is obtained after the light components and heavy components are removed.

[0053] In the above technical solution, the antioxidant 2,4-dimethyl-6-tert-butyl phenol is obtained by cracking the antioxidant 2246, the by-product is recycled to prepare the antioxidant 2246, and the recycling of the by-product is realized. The reaction mechanism is that the double methylene of the antioxidant 2246 is extremely unstable under high temperature conditions and is prone to break to form one molecule of 2,4-dimethyl-6-tert-butyl phenol and one molecule of 2-tert-butyl p-cresol, then hydrogen is generated in the presence of methanol and sodium hydroxide, one molecule of 2,4-dimethyl-6-tert-butyl phenol is generated in the presence of hydrogen and methanol, and one molecule of 2,4-dimethyl-6-tert-butyl phenol is generated in the presence of hydrogen and methanol. In the whole reaction process, one molecule of antioxidant 2246 finally generates two molecules of 2,4-dimethyl-6-tert-butyl phenol.

[0054] In one specific technical solution, in step S1, the base catalyst is at least one of sodium hydroxide and potassium hydroxide; and the co-catalyst is at least one of zinc oxide, copper oxide and aluminum oxide.

[0055] In one specific technical solution, in step S1, the mass of the base catalyst is 5-50wt% of the mass of the antioxidant 2246; the mass of the co-catalyst is 1-10wt% of the mass of the antioxidant 2246; and the mass ratio of the methanol to the antioxidant 2246 is (2-15):1.

[0056] In one specific technical solution, in step S1, the reaction temperature is 200-300℃, the reaction pressure is 7-20MPa, and the reaction time is 3-10h; in step S2, the temperature of the vacuum distillation is 25-45℃, and the pressure is 50-80KPa; in step S3, the temperature of the vacuum distillation is 25-45℃, the pressure is 50-80KPa, the column top temperature of the vacuum rectification is 160-200℃, the column top temperature is 90-130℃, the column temperature is 140-180℃, and the pressure is 99KPa.

[0057] Example 2-1

[0058] Into a synthesis device, 100 parts by mass of antioxidant 2246, 200 parts by mass of methanol, 20 parts by mass of sodium hydroxide and 2 parts by mass of zinc oxide were added, and the reaction was stirred at 220°C and 15 MPa for 4 hours, to obtain a reaction completion liquid. The reaction completion liquid was cooled to room temperature, and then filtered to remove the zinc oxide. The methanol was removed by distillation under reduced pressure at 30°C and 70 KPa, and then the organic phase was obtained by extraction with petroleum ether. The organic phase was washed with water, dried with anhydrous sodium sulfate, and then distilled under reduced pressure at 30°C and 70 KPa, to obtain a crude product. The crude product was placed in a φ25 packed glass rectifying column, the packing was φ3 stainless steel triangular spiral packing, the column length was 400 mm, the plate height was 40 mm, the theoretical plate number was 10, and the distillation was performed under reduced pressure at a column top temperature of 107°C, a column length temperature of 160°C, and a pressure of 99 KPa, to obtain 2,4-dimethyl-6-tert-butylphenol after removing light components and heavy components. The 2,4-dimethyl-6-tert-butylphenol was a colorless transparent liquid, the yield was 95.3%, and the purity was 99.5%.

[0059] Example 2-2

[0060] Into a synthesis device, 100 parts by mass of antioxidant 2246, 200 parts by mass of methanol, 20 parts by mass of sodium hydroxide and 2 parts by mass of zinc oxide were added, and the reaction was stirred at 280°C and 10 MPa for 3 hours, to obtain a reaction completion liquid. The reaction completion liquid was cooled to room temperature, and then filtered to remove the zinc oxide. The methanol was removed by distillation under reduced pressure at 30°C and 70 KPa, and then the organic phase was obtained by extraction with petroleum ether. The organic phase was washed with water, dried with anhydrous sodium sulfate, and then distilled under reduced pressure at 30°C and 70 KPa, to obtain a crude product. The crude product was placed in a φ25 packed glass rectifying column, the packing was φ3 stainless steel triangular spiral packing, the column length was 400 mm, the plate height was 40 mm, the theoretical plate number was 10, and the distillation was performed under reduced pressure at a column top temperature of 107°C, a column length temperature of 160°C, and a pressure of 99 KPa, to obtain 2,4-dimethyl-6-tert-butylphenol after removing light components and heavy components. The 2,4-dimethyl-6-tert-butylphenol was a colorless transparent liquid, the yield was 95.1%, and the purity was 99.2%.

[0061] Example 2-3

[0062] The synthesis device was added with 100 parts by mass of antioxidant 2246, 200 parts by mass of methanol, 20 parts by mass of sodium hydroxide, and 2 parts by mass of zinc oxide, and stirred at 200°C and 15MPa for 5h to obtain a reaction completion liquid; the reaction completion liquid was cooled to room temperature, and first filtered to remove zinc oxide, and then distilled at 30°C and 70KPa to remove methanol, and finally extracted with petroleum ether to obtain an organic phase; the organic phase was sequentially subjected to water washing, anhydrous sodium sulfate drying, and distillation at 30°C and 70KPa to obtain a crude product, which was placed into a φ25 packed glass rectifying column with φ3 stainless steel triangular spiral packing, a column length of 400mm, an equal plate height of 40mm, and a theoretical plate number of 10, and subjected to vacuum rectification at a column bottom temperature of 180°C, a column top temperature of 107°C, a column temperature of 160°C, and a pressure of 99KPa to obtain 2,4-dimethyl-6-tert-butylphenol after removing light components and heavy components. The 2,4-dimethyl-6-tert-butylphenol was a colorless transparent liquid, with a yield of 93.6% and a purity of 99.1%.

[0063] Example 2-4

[0064] The synthesis device was added with 100 parts by mass of antioxidant 2246, 200 parts by mass of methanol, 20 parts by mass of sodium hydroxide, and 2 parts by mass of zinc oxide, and stirred at 200°C and 15MPa for 5h to obtain a reaction completion liquid; the reaction completion liquid was cooled to room temperature, and first filtered to remove zinc oxide, and then distilled at 30°C and 70KPa to remove methanol, and finally extracted with petroleum ether to obtain an organic phase; the organic phase was sequentially subjected to water washing, anhydrous sodium sulfate drying, and distillation at 30°C and 70KPa to obtain a crude product, which was placed into a φ25 packed glass rectifying column with φ3 stainless steel triangular spiral packing, a column length of 400mm, an equal plate height of 40mm, and a theoretical plate number of 10, and subjected to vacuum rectification at a column bottom temperature of 180°C, a column top temperature of 107°C, a column temperature of 160°C, and a pressure of 99KPa to obtain 2,4-dimethyl-6-tert-butylphenol after removing light components and heavy components. The 2,4-dimethyl-6-tert-butylphenol was a colorless transparent liquid, with a yield of 93.6% and a purity of 99.1%.

[0065] Example 2-5

[0066] The synthesis device was added with 100 parts by mass of antioxidant 2246, 500 parts by mass of methanol, 30 parts by mass of sodium hydroxide and 5 parts by mass of zinc oxide, and stirred at 220 ℃ and 15 MPa for 4 h to obtain a reaction completion liquid; the reaction completion liquid was cooled to room temperature, and first filtered to remove zinc oxide, and then distilled at 30 ℃ and 70 KPa to remove methanol, and finally extracted with petroleum ether to obtain an organic phase; the organic phase was sequentially subjected to water washing, anhydrous sodium sulfate drying and distillation at 30 ℃ and 70 KPa to obtain a crude product, which was placed into a φ25 packed glass rectifying column with φ3 stainless steel triangular spiral packing, a column length of 400 mm, an equal plate height of 40 mm and a theoretical plate number of 10, and subjected to vacuum rectification at a column bottom temperature of 180 ℃, a column top temperature of 107 ℃, a column temperature of 160 ℃ and a pressure of 99 KPa to obtain 2,4-dimethyl-6-tert-butylphenol after removal of light components and heavy components. The 2,4-dimethyl-6-tert-butylphenol was a colorless transparent liquid, with a yield of 96.5% and a purity of 99.7%.

[0067] Example 2-6

[0068] The synthesis device was added with 100 parts by mass of antioxidant 2246, 500 parts by mass of methanol, 30 parts by mass of sodium hydroxide and 5 parts by mass of zinc oxide, and stirred at 220 ℃ and 15 MPa for 4 h to obtain a reaction completion liquid; the reaction completion liquid was cooled to room temperature, and first filtered to remove zinc oxide, and then distilled at 30 ℃ and 70 KPa to remove methanol, and finally extracted with petroleum ether to obtain an organic phase; the organic phase was sequentially subjected to water washing, anhydrous sodium sulfate drying and distillation at 30 ℃ and 70 KPa to obtain a crude product, which was placed into a φ25 packed glass rectifying column with φ3 stainless steel triangular spiral packing, a column length of 400 mm, an equal plate height of 40 mm and a theoretical plate number of 10, and subjected to vacuum rectification at a column bottom temperature of 180 ℃, a column top temperature of 107 ℃, a column temperature of 160 ℃ and a pressure of 99 KPa to obtain 2,4-dimethyl-6-tert-butylphenol after removal of light components and heavy components. The 2,4-dimethyl-6-tert-butylphenol was a colorless transparent liquid, with a yield of 96.5% and a purity of 99.7%.

[0069] Example 2-7

[0070] The synthesis device was added with 100 parts by mass of antioxidant 2246, 200 parts by mass of methanol, 20 parts by mass of sodium hydroxide and 2 parts by mass of copper oxide, and stirred at 220 ℃ and 15 MPa for 4 h to obtain a reaction completion liquid; the reaction completion liquid was cooled to room temperature, and first filtered to remove copper oxide, and then distilled at 30 ℃ and 70 KPa to remove methanol, and finally extracted with petroleum ether to obtain an organic phase; the organic phase was sequentially subjected to water washing, anhydrous sodium sulfate drying and distillation at 30 ℃ and 70 KPa to obtain a crude product, which was placed into a φ25 packed glass rectifying column with φ3 stainless steel triangular spiral packing, a column length of 400 mm, an equal plate height of 40 mm and a theoretical plate number of 10, and subjected to vacuum rectification at a column bottom temperature of 180 ℃, a column top temperature of 107 ℃, a column temperature of 160 ℃ and a pressure of 99 KPa to obtain 2,4-dimethyl-6-tert-butylphenol after removal of light components and heavy components. The 2,4-dimethyl-6-tert-butylphenol was a colorless transparent liquid, with a yield of 95.1% and a purity of 99.2%.

[0071] Example 2-8

[0072] The synthesis device was added with 100 parts by mass of antioxidant 2246, 200 parts by mass of methanol, 20 parts by mass of sodium hydroxide and 2 parts by mass of copper oxide, and stirred at 220 ℃ and 15 MPa for 4 h to obtain a reaction completion liquid; the reaction completion liquid was cooled to room temperature, and first filtered to remove copper oxide, and then distilled at 30 ℃ and 70 KPa to remove methanol, and finally extracted with petroleum ether to obtain an organic phase; the organic phase was sequentially subjected to water washing, anhydrous sodium sulfate drying and distillation at 30 ℃ and 70 KPa to obtain a crude product, which was placed into a φ25 packed glass rectifying column with φ3 stainless steel triangular spiral packing, a column length of 400 mm, an equal plate height of 40 mm and a theoretical plate number of 10, and subjected to vacuum rectification at a column bottom temperature of 180 ℃, a column top temperature of 107 ℃, a column temperature of 160 ℃ and a pressure of 99 KPa to obtain 2,4-dimethyl-6-tert-butylphenol after removal of light components and heavy components. The 2,4-dimethyl-6-tert-butylphenol was a colorless transparent liquid, with a yield of 95.1% and a purity of 99.2%.

[0073] Example 2-9

[0074] The synthesis device is added with 100 parts by mass of antioxidant 2246, 200 parts by mass of methanol, 20 parts by mass of potassium hydroxide and 2 parts by mass of zinc oxide, and stirred at 220℃ and 15MPa for 4h to obtain a reaction completion liquid; the reaction completion liquid is cooled to room temperature, and first filtered to remove zinc oxide, then distilled at 30℃ and 70KPa to remove methanol, and finally extracted with petroleum ether to obtain an organic phase; the organic phase is sequentially subjected to water washing, anhydrous sodium sulfate drying and distillation at 30℃ and 70KPa to obtain a crude product, which is placed into a φ25 packed glass rectifying column with φ3 stainless steel triangular spiral packing, a column length of 400mm, an equal plate height of 40mm and a theoretical plate number of 10, and subjected to vacuum rectification at a column bottom temperature of 180℃, a column top temperature of 107℃, a column temperature of 160℃ and a pressure of 99KPa to obtain 2,4-dimethyl-6-tert-butyl phenol after removing light components and heavy components. The 2,4-dimethyl-6-tert-butyl phenol is a colorless transparent liquid, with a yield of 95.3% and a purity of 99.5%.

[0075] Example 2-10

[0076] The synthesis device is added with 100 parts by mass of antioxidant 2246, 200 parts by mass of methanol, 20 parts by mass of potassium hydroxide and 2 parts by mass of zinc oxide, and stirred at 220℃ and 15MPa for 4h to obtain a reaction completion liquid; the reaction completion liquid is cooled to room temperature, and first filtered to remove zinc oxide, then distilled at 30℃ and 70KPa to remove methanol, and finally extracted with petroleum ether to obtain an organic phase; the organic phase is sequentially subjected to water washing, anhydrous sodium sulfate drying and distillation at 30℃ and 70KPa to obtain a crude product, which is placed into a φ25 packed glass rectifying column with φ3 stainless steel triangular spiral packing, a column length of 400mm, an equal plate height of 40mm and a theoretical plate number of 10, and subjected to vacuum rectification at a column bottom temperature of 180℃, a column top temperature of 107℃, a column temperature of 160℃ and a pressure of 99KPa to obtain 2,4-dimethyl-6-tert-butyl phenol after removing light components and heavy components. The 2,4-dimethyl-6-tert-butyl phenol is a colorless transparent liquid, with a yield of 95.3% and a purity of 99.5%.

[0077] The above examples are preferred embodiments of the present application, but the embodiments of the present application are not limited to the above examples, and any changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principles of the present application shall be equivalent replacement modes and shall be within the protection scope of the present application.

Claims

1. A process for the synthesis of 2,4-dimethyl-6-tert-butylphenol, characterized in that, The method comprises the following steps: S1, adding antioxidant 2246, methanol, base catalyst and co-catalyst into the reaction cavity (12) of the synthesis device, stirring the reaction under the reaction temperature and pressure, the hydrogen generated in the reaction enters the hydrogen cavity (11) through the filter plate (2), then is sprayed into the reaction material through the hydrogen tube (3), the stirring shaft (4) and the nozzle (7) to promote the reaction, and the reaction completed liquid is obtained after the reaction is completed; S2, cooling the reaction completed liquid to room temperature, removing the co-catalyst by filtration, removing the methanol by vacuum distillation, and finally extracting the organic phase with petroleum ether; S3, the organic phase is sequentially subjected to water washing, drying with anhydrous sodium sulfate, and vacuum distillation, and then the crude product is obtained, the crude product is placed into a rectifying column for vacuum rectification, and 2,4-dimethyl-6-tert-butyl phenol is obtained after the light components and heavy components are removed. The synthesis device in step S1 comprises a closed tank body (1), a filter plate (2) allowing only hydrogen to pass through is horizontally arranged in the tank body (1), a hydrogen cavity (11) is arranged above the filter plate (2), and a reaction cavity (12) is arranged below the filter plate (2); the reaction cavity (12) is provided with a hydrogen tube (3) penetrating through and fixed at the center of the filter plate (2) and a hollow stirring shaft (4) with an open top and in sealed rotary connection with the hydrogen tube (3); the lower end of the stirring shaft (4) is connected with a motor (6), the outer side wall is provided with stirring blades (5) and a one-way gas nozzle (7) in communication with the hollow of the stirring shaft (4); the hydrogen tube (3) is provided with a pressure increasing mechanism (8), the pressure increasing mechanism (8) comprises an annular piston (81) which is sealed and damped and lifted along the hydrogen tube (3), a lifting tube (82) which can be sealed and vertically slid a certain distance relative to the piston (81) is arranged at the center of the piston (81), the top of the lifting tube (82) is sealed, the outer side wall is provided with a side hole (821) which can be blocked by the piston (81), the bottom extends downward to above the nozzle (7) and is provided with a ring-shaped flange (824) which is in sealed rotary abutment with the inner side wall of the stirring shaft (4), when the lifting tube (82) moves upward relative to the piston (81), the side hole (821) can be unblocked, and a cam mechanism (83) connected with the stirring shaft (4) and the lifting tube (82) can drive the lifting tube (82) to lift; a first guide groove (31) is vertically arranged on the inner side wall of the hydrogen tube (3), a first sliding block (811) matched with the first guide groove (31) is arranged on the outer side wall of the piston (81), and a second sliding block (812) is arranged on the inner side wall; a sealing cover (822) is arranged at the top of the lifting tube (82), and a second guide groove (823) for vertical sliding of the second sliding block (812) is arranged on the side wall.

2. The method of claim 1, wherein the 2,4-dimethyl-6-tert-butylphenol is synthesized by the reaction of 2,4-dimethylphenol and tert-butyl hydroperoxide in the presence of a base. In step S1, the base catalyst is at least one of sodium hydroxide and potassium hydroxide; and the co-catalyst is at least one of zinc oxide, copper oxide and aluminum oxide.

3. The method of claim 1, wherein the 2,4-dimethyl-6-tert-butylphenol is synthesized by the reaction of 2,4-dimethylphenol and tert-butyl hydroperoxide in the presence of a base. In step S1, the mass of the base catalyst is 5-50wt% of the mass of the antioxidant 2246; the mass of the co-catalyst is 1-10wt% of the mass of the antioxidant 2246; and the mass ratio of the methanol to the antioxidant 2246 is (2-15):

1.

4. The method for synthesizing 2,4-dimethyl-6-tert-butylphenol according to claim 1, characterized in that, In step S1, the reaction temperature is 200-300℃, the reaction pressure is 7-20MPa, and the reaction time is 3-10h; in step S2, the temperature for the vacuum distillation is 25-45℃, and the pressure is 50-80KPa; in step S3, the temperature for the vacuum distillation is 25-45℃, the pressure is 50-80KPa, the column bottom temperature for the vacuum rectification is 160-200℃, the column top temperature is 90-130℃, the column temperature is 140-180℃, and the pressure is 99KPa.

Images