Preparation method of anisaldehyde

Abstract

The invention relates to the technical field of anisaldehyde, in particular to a preparation method of anisaldehyde, which comprises the following steps: adding dimethylbenzene and a catalyst of modified cobalt hydroxide into a reaction kettle, slowly dropwise adding glacial acetic acid into the reaction kettle, controlling the temperature at 80-110 DEG C, and keeping a total reflux state for 2 hours. In the preparation of anisaldehyde, the catalyst of dimethylbenzene and modified cobalt hydroxide is matched with glacial acetic acid, and the anisaldehyde is prepared by a specific process, so that the conversion rate of the obtained anisaldehyde is high, the selectivity of the product is excellent, and the conversion rate of raw materials and the selectivity of the product are high.

Description

Technical Field

[0001] The present invention relates to the technical field of anisaldehyde, and specifically relates to a preparation method of anisaldehyde. Background Art

[0002] The chemical name of anisaldehyde is p-methoxybenzaldehyde, which has a relatively wide range of applications. It has a persistent hawthorn aroma and is fragrant and attractive, so it is widely used in the preparation of various flavors such as sweet floral flavors, hawthorn flavors, and clove flavors, as well as the preparation of flavors for food, sugars, and beverages; in the pharmaceutical field, it is an important intermediate for the preparation of anti-vitamin drugs (such as hydroxybenzyl penicillin, porphyrin photosensitizers, etc.); in the electroplating industry, it can be used as an excellent brightener for non-cyanide zinc plating DE additives; in the agricultural field, anisaldehyde can be used as an insecticide, insecticide additive, biological growth inhibitor, etc. Due to the excellent properties of anisaldehyde, it has been widely used.

[0003] Currently, industrial production mainly uses the p-hydroxybenzaldehyde method to prepare anisaldehyde, that is, it is prepared by the alkylation reaction of p-hydroxybenzaldehyde with dimethyl sulfate. Compared with other methods such as anethole oxidation method, anisole chloromethylation method, p-cresol synthesis method, etc., this method has the advantages of short production cycle, high yield, and low cost. However, dimethyl sulfate is a highly toxic substance, which is extremely harmful to the human body and the environment. The whole process of transportation, storage, and use is under control. The treatment of wastewater containing dimethyl sulfate is difficult and costly. To solve the above problems, the company organized and implemented the research and development of this project. Summary of the Invention

[0004] Aiming at the defects of the prior art, the purpose of the present invention is to provide a preparation method of anisaldehyde to solve the problems raised in the above background art.

[0005] The present invention solves the technical problems by adopting the following technical solutions: The present invention provides a preparation method of anisaldehyde, which includes the following steps: Step 1: Add xylene and a catalyst of modified cobalt hydroxide into the reaction kettle, and slowly drip glacial acetic acid into the reaction kettle, control the temperature at 80-110 degrees, and maintain the total reflux state for 2 hours; Step 2: Filter and separate the catalyst and the mother liquor through a filter press, and separate the oil phase and the water phase after the mother liquor stands still; Step 3: Transfer the oil phase to the distillation kettle, the materials in the kettle are vaporized after being heated by the heat transfer oil, the materials in the kettle are vaporized after being heated by the heat transfer oil, the vapor phase rises and enters the distillation column; Step 4: Obtain anisaldehyde through distillation in the distillation column.

[0006] Preferably, the process steps of distillation in Step 4 are as follows: After the gas phase at the top of the tower is condensed by the top condenser, it enters the reflux ratio distributor. After the distribution, a part of the material refluxes from the top of the distillation tower. The rising steam and the refluxed liquid transfer heat and mass in the distillation tower to form a stable concentration gradient and temperature gradient. The other stream of material is cooled by the top cooler according to the sampling results and then collected into different fraction tanks. When the top temperature of the distillation tower rises and stabilizes at 130℃~160℃, close the reflux ratio distributor for full reflux operation, take samples for inspection of the top fraction, and start to extract the product fraction when the product fraction is qualified. Then check the bottom liquid level and the temperature changes of the tower sections. When the bottom liquid level is ≤250mm or the top temperature starts to rise, the single batch distillation is completed.

[0007] Preferably, the preparation method of the modified cobalt hydroxide catalyst is: S01: Preparation of modified composite liquid: S01a: Add 2 to 4 parts by weight of sodium dodecylbenzene sulfonate solution and 1 to 3 parts by weight of silane coupling agent KH550 to 5 to 8 parts by weight of 4% yttrium nitrate solution, then add 3 to 5 parts by weight of nano titanium dioxide, stir evenly, and obtain a first modified solution; S01b: 2 to 3 parts by weight of cerium oxide and 1 to 3 parts by weight of aluminum oxide are mixed and added into 5 to 8 parts by weight of dopamine hydrochloride solution and mixed thoroughly to obtain a second modified solution; S01c: fully stirring the first modified liquid and the second modified liquid at a weight ratio of 3:5 to obtain a modified composite liquid; S02: Cobalt hydroxide is preheated at 55-60°C for 1h, and the preheated cobalt hydroxide is added to the modified composite liquid in a weight ratio of 2:(4-5) and stirred for modification. After the stirring is completed, a modified cobalt hydroxide liquid is obtained; S03: The modified cobalt hydroxide solution and the loaded ball milling agent are mixed in a weight ratio of 5:3, and the ball milling is performed at a ball milling speed of 1000-1500 r / min for 2 hours. After the ball milling is completed, the modified cobalt hydroxide catalyst is obtained by suction filtration and drying.

[0008] The catalyst of modified cobalt hydroxide uses cobalt hydroxide as the matrix, which is improved and optimized through a modified composite solution. The first modified solution and the second modified solution in the modified composite solution are coordinated. The sodium dodecylbenzenesulfonate solution, silane coupling agent KH550, yttrium nitrate solution with a mass fraction of 4%, and nano-titanium dioxide in the first modified solution are blended and improved. Through the coordination and improvement of raw materials, the prepared first modified solution uses nano-titanium dioxide as the matrix and is combined with the yttrium nitrate solution to enhance the interfacial property and contact activity degree between raw materials. The second modified solution is prepared by blending cerium oxide, alumina, and dopamine hydrochloride solution, and the co-adjustment and optimization of cerium oxide, alumina, and dopamine hydrochloride solution used at the same time can further enhance the catalytic activity of cobalt hydroxide in the system, thereby optimizing the raw material conversion rate and product selectivity of the product.

[0009] Preferably, the mass fraction of the dopamine hydrochloride solution is 4-7%; the mass fraction of the sodium dodecylbenzenesulfonate solution is 2-5%.

[0010] Preferably, the stirring speed of the stirring modification treatment is 550-750 r / min, and the stirring is carried out for 1 h.

[0011] Preferably, the preparation method of the load ball milling agent is as follows: S101: Irradiate carbon nanotubes in a proton irradiation chamber for 1 h, with an irradiation power of 400-500 W. After the irradiation ends, the irradiated carbon nanotubes are obtained; The irradiated carbon nanotubes are then subjected to heat improvement treatment. The specific improvement method is as follows: First, heat up at a rate of 2-5 °C / min to 220-230 °C, keep warm for 15 min, then heat up at a rate of 1-3 °C / min to 350 °C, keep warm for 35 min, and finally air-cool to room temperature; S102: Ultrasonically treat the carbon nanotubes treated in S101 and the ball milling liquid according to a weight ratio of 3:5. After the ultrasonic treatment ends, filter and dry to obtain the load ball milling agent.

[0012] Preferably, the ultrasonic power of the ultrasonic treatment is 350-400 W, and the ultrasonic treatment is carried out for 1 h.

[0013] Preferably, the ball milling liquid includes the following components by weight: 3-5 parts of kaolin, 4-6 parts of lanthanum chloride solution, 2-3 parts of aluminum borate whiskers, 1-2 parts of bismuth titanate, and 0.5-0.7 parts of urea solution.

[0014] Preferably, the mass fraction of the urea solution is 4-6%; the mass fraction of the lanthanum chloride solution is 2-5%.

[0015] The modified cobalt hydroxide solution is improved by cooperating with a load ball milling agent. The load ball milling agent irradiates carbon nanotubes to activate their activity efficiency. At the same time, it is further improved by heat treatment. Through continuous heat improvement optimization, the activity of carbon nanotubes is further enhanced. At the same time, the added ball milling liquid is used to improve carbon nanotubes. The kaolin, lanthanum chloride solution, aluminum borate whiskers, bismuth titanate and urea solution in the ball milling liquid are coordinated through the blending of raw materials. Through the layered structure of kaolin and the whisker structure of whiskers, they are distributed into the system, further enhancing the stability of the catalyst system. The obtained catalyst has remarkable performance stability under acid corrosion and alkali corrosion conditions.

[0016] Compared with the prior art, the present invention has the following beneficial effects: In the preparation of anisaldehyde of the present invention, xylene, a catalyst of modified cobalt hydroxide and glacial acetic acid are used and prepared through the specific process of the present invention. The obtained anisaldehyde has a high conversion rate, excellent product selectivity, high raw material conversion rate and high product selectivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is the GC-MS analysis chart of the present invention; Figure 2 It is the infrared analysis report chart of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] The following combines specific embodiments to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the scope of protection of the present invention.

[0019] A method for preparing anisaldehyde in this embodiment includes the following steps: Step 1: Add xylene and a catalyst of modified cobalt hydroxide into the reaction kettle, and slowly drop glacial acetic acid into the reaction kettle, control the temperature at 80-110 degrees, and maintain the total reflux state for 2 hours; Step 2: Filter and separate the catalyst and the mother liquor through a filter press, and separate the oil phase and the water phase after the mother liquor stands still; Step 3: Transfer the oil phase to the distillation kettle, and the materials in the kettle are vaporized after being heated by heat transfer oil. The materials in the kettle are vaporized after being heated by heat transfer oil, and the vapor phase rises and enters the distillation column; Step 4: Obtain anisaldehyde through distillation in the distillation column.

[0020] The process steps of distillation in Step 4 of this embodiment are as follows: After the gas phase at the top of the tower is condensed by the top condenser, it enters the reflux ratio distributor. After the distribution, a part of the material refluxes from the top of the distillation tower. The rising steam and the refluxed liquid transfer heat and mass in the distillation tower to form a stable concentration gradient and temperature gradient. The other stream of material is cooled by the top cooler according to the sampling results and then collected into different fraction tanks. When the top temperature of the distillation tower rises and stabilizes at 130℃~160℃, close the reflux ratio distributor for full reflux operation, take samples for inspection of the top fraction, and start to extract the product fraction when the product fraction is qualified. Then check the bottom liquid level and the temperature changes of the tower sections. When the bottom liquid level is ≤250mm or the top temperature starts to rise, the single batch distillation is completed.

[0021] The preparation method of the modified cobalt hydroxide catalyst of this embodiment is: S01: Preparation of modified composite liquid: S01a: Add 2 to 4 parts by weight of sodium dodecylbenzene sulfonate solution and 1 to 3 parts by weight of silane coupling agent KH550 to 5 to 8 parts by weight of 4% yttrium nitrate solution, then add 3 to 5 parts by weight of nano titanium dioxide, stir evenly, and obtain a first modified solution; S01b: 2 to 3 parts by weight of cerium oxide and 1 to 3 parts by weight of aluminum oxide are mixed and added into 5 to 8 parts by weight of dopamine hydrochloride solution and mixed thoroughly to obtain a second modified solution; S01c: fully stirring the first modified liquid and the second modified liquid in a weight ratio of 3:5 to obtain a modified composite liquid; S02: Cobalt hydroxide is preheated at 55-60°C for 1h, and the preheated cobalt hydroxide is added to the modified composite liquid in a weight ratio of 2:(4-5) and stirred for modification. After the stirring is completed, a modified cobalt hydroxide liquid is obtained; S03: The modified cobalt hydroxide solution and the loaded ball milling agent are mixed in a weight ratio of 5:3, and the ball milling is performed at a ball milling speed of 1000-1500 r / min for 2 hours. After the ball milling is completed, the modified cobalt hydroxide catalyst is obtained by suction filtration and drying.

[0022] The mass fraction of the dopamine hydrochloride solution in this embodiment is 4-7%; the mass fraction of the sodium dodecylbenzene sulfonate solution is 2-5%.

[0023] The stirring speed of the stirring modification treatment in this embodiment is 550-750 r / min, and the stirring is for 1 hour.

[0024] The preparation method of the loaded ball mill of this embodiment is: S101: irradiating the carbon nanotubes in a proton irradiation box for 1 hour at an irradiation power of 400 to 500 W, and obtaining irradiated carbon nanotubes after the irradiation is completed; The irradiated carbon nanotubes are reheated and improved. The specific improvement method is as follows: First, heat it at a rate of 2 - 5 °C / min to 220 - 230 °C, hold for 15 min, then heat it at a rate of 1 - 3 °C / min to 350 °C, hold for 35 min, and finally air-cool it to room temperature; S102: Ultrasonically treat the carbon nanotubes treated in S101 and the ball milling liquid in a weight ratio of 3:5. After the ultrasonic treatment is completed, filter by suction and dry to obtain the supported ball milling agent.

[0025] In this embodiment, the ultrasonic power of the ultrasonic treatment is 350 - 400 W, and the ultrasonic treatment is carried out for 1 h.

[0026] The ball milling liquid in this embodiment comprises the following components by weight: 3 - 5 parts of kaolin, 4 - 6 parts of lanthanum chloride solution, 2 - 3 parts of aluminum borate whiskers, 1 - 2 parts of bismuth titanate, and 0.5 - 0.7 parts of urea solution.

[0027] In this embodiment, the mass fraction of the urea solution is 4 - 6%; the mass fraction of the lanthanum chloride solution is 2 - 5%.

[0028] Example 1 A preparation method of anisaldehyde in this embodiment comprises the following steps: Step 1: Add xylene and a catalyst of modified cobalt hydroxide into a reaction kettle, slowly drip glacial acetic acid into the reaction kettle, control the temperature at 80 °C, and maintain the total reflux state for 2 hours; Step 2: Filter and separate the catalyst and the mother liquor through a filter press, and separate the oil phase and the water phase after the mother liquor stands still; Step 3: Transfer the oil phase to a rectification kettle. The materials in the kettle are vaporized after being heated by heat transfer oil. The materials in the kettle are vaporized after being heated by heat transfer oil. The vapor phase rises and enters the rectification tower; Step 4: Obtain anisaldehyde through rectification in the rectification tower.

[0029] The rectification process steps in Step 4 of this embodiment are as follows: The gas phase at the top of the tower is condensed by a condenser at the top of the tower and then enters a reflux ratio distributor. After the distribution, a part of the materials flows back from the top of the rectification tower. The rising steam and the refluxing liquid carry out heat and mass transfer in the rectification tower to form a stable concentration gradient and temperature gradient. Another part of the materials is cooled by a cooler at the top of the tower according to the sampling results and then collected into different fraction tanks; When the temperature at the top of the rectification tower rises and stabilizes at 130 °C, close the full reflux operation of the reflux ratio distributor, take a sample for detection of the fraction at the top of the tower. When the detected product fraction is qualified, start collecting the product fraction, and then check the change of the liquid level in the kettle and the temperature of the tower section. When the liquid level in the kettle ≤ 250 mm or the temperature at the top of the tower starts to rise, the single-batch rectification ends.

[0030] The preparation method of the catalyst of modified cobalt hydroxide in this embodiment is: S01: Preparation of modified composite liquid: S01a: 2 parts by weight of sodium dodecylbenzene sulfonate solution and 1 part by weight of silane coupling agent KH550 are added to 5 parts by weight of 4% yttrium nitrate solution, and then 3 parts by weight of nano titanium dioxide are added and stirred to obtain a first modified solution; S01b: 2 parts by weight of cerium oxide and 1 part by weight of aluminum oxide are mixed and added into 5 parts by weight of dopamine hydrochloride solution and mixed thoroughly to obtain a second modified solution; S01c: fully stirring the first modified liquid and the second modified liquid at a weight ratio of 3:5 to obtain a modified composite liquid; S02: cobalt hydroxide is preheated at 55° C. for 1 h, and the preheated cobalt hydroxide is added to the modified composite liquid at a weight ratio of 2:4 and stirred for modification. After the stirring is completed, a modified cobalt hydroxide liquid is obtained; S03: The modified cobalt hydroxide solution and the loaded ball milling agent are mixed in a weight ratio of 5:3, and the mixture is ball milled at a speed of 1000 r / min for 2 h. After the ball milling is completed, the mixture is filtered and dried to obtain a modified cobalt hydroxide catalyst.

[0031] The mass fraction of the dopamine hydrochloride solution in this embodiment is 4%; the mass fraction of the sodium dodecylbenzenesulfonate solution is 2%.

[0032] The stirring speed of the stirring modification treatment in this embodiment is 550 r / min, and the stirring is for 1 hour.

[0033] The preparation method of the loaded ball mill of this embodiment is: S101: irradiating the carbon nanotubes in a proton irradiation box for 1 hour at an irradiation power of 400 W, and obtaining irradiated carbon nanotubes after the irradiation is completed; The irradiated carbon nanotubes are reheated and improved. The specific improvement method is as follows: First, heat to 220℃ at a rate of 2℃ / min, keep warm for 15min, then heat to 350℃ at a rate of 1℃ / min, keep warm for 35min, and finally air cool to room temperature; S102: The carbon nanotubes treated in S101 and the ball milling solution are subjected to ultrasonic treatment at a weight ratio of 3:5. After the ultrasonic treatment is completed, the mixture is filtered and dried to obtain a loaded ball milling agent.

[0034] The ultrasonic treatment in this embodiment was performed with an ultrasonic power of 350 W and for 1 h.

[0035] The ball milling liquid of this embodiment comprises the following components by weight: 3 parts of kaolin, 4 parts of lanthanum chloride solution, 2 parts of aluminum borate whiskers, 1 part of bismuth titanate and 0.5 parts of urea solution.

[0036] The mass fraction of the urea solution in this embodiment is 4%; the mass fraction of the lanthanum chloride solution is 2%.

[0037] Example 2 A method for preparing anisaldehyde of the present embodiment comprises the following steps: Step 1: Add xylene and modified cobalt hydroxide catalyst into the reactor, slowly add glacial acetic acid to the reactor, control the temperature at 110 degrees, and maintain full reflux for 2 hours; Step 2: filtering the catalyst and the mother liquor through a filter press, and separating the oil phase and the water phase after the mother liquor is allowed to stand; Step 3: The oil phase is pumped into the distillation kettle, and the material in the kettle is vaporized after being heated by the heat transfer oil. The material in the kettle is vaporized after being heated by the heat transfer oil, and the vapor phase rises and enters the distillation tower; Step 4: obtain anisaldehyde by distillation through a distillation tower.

[0038] The process steps of distillation in step 4 of this embodiment are: After the gas phase at the top of the tower is condensed by the top condenser, it enters the reflux ratio distributor. After the distribution, a part of the material refluxes from the top of the distillation tower. The rising steam and the refluxed liquid transfer heat and mass in the distillation tower to form a stable concentration gradient and temperature gradient. The other stream of material is cooled by the top cooler according to the sampling results and then collected into different fraction tanks. When the top temperature of the distillation tower rises and stabilizes at 160℃, close the reflux ratio distributor for full reflux operation, take samples of the top fraction for inspection, and start to extract the product fraction when the product fraction is qualified. Then check the bottom liquid level and the temperature changes of the tower sections. When the bottom liquid level is ≤250mm or the top temperature starts to rise, the single batch distillation is completed.

[0039] The preparation method of the modified cobalt hydroxide catalyst of this embodiment is: S01: Preparation of modified composite liquid: S01a: 4 parts by weight of sodium dodecylbenzene sulfonate solution and 3 parts by weight of silane coupling agent KH550 are added to 8 parts by weight of 4% yttrium nitrate solution, and then 5 parts by weight of nano titanium dioxide are added and stirred to obtain a first modified solution; S01b: 3 parts by weight of cerium oxide and 3 parts by weight of aluminum oxide are mixed and added into 8 parts by weight of dopamine hydrochloride solution and mixed thoroughly to obtain a second modified solution; S01c: fully stirring the first modified liquid and the second modified liquid in a weight ratio of 3:5 to obtain a modified composite liquid; S02: cobalt hydroxide is preheated at 60° C. for 1 h, and the preheated cobalt hydroxide is added to the modified composite liquid at a weight ratio of 2:5 and stirred for modification. After the stirring is completed, a modified cobalt hydroxide liquid is obtained; S03: Mix the modified cobalt hydroxide solution and the supported ball milling agent in a weight ratio of 5:3, perform ball milling at a speed of 1500 r / min for 2 h. After the ball milling is completed, carry out suction filtration and drying to obtain the catalyst of modified cobalt hydroxide.

[0040] In this example, the mass fraction of the dopamine hydrochloride solution is 7%; the mass fraction of the sodium dodecylbenzenesulfonate solution is 5%.

[0041] In this example, the stirring speed for the stirring modification treatment is 750 r / min, and the stirring is carried out for 1 h.

[0042] The preparation method of the supported ball milling agent in this example is as follows: S101: Irradiate the carbon nanotubes in a proton irradiation chamber for 1 h with an irradiation power of 500 W. After the irradiation is completed, obtain the irradiated carbon nanotubes; The irradiated carbon nanotubes are then subjected to heat improvement treatment. The specific improvement method is as follows: First, heat up at a rate of 5 °C / min to 230 °C, hold for 15 min, then heat up at a rate of 3 °C / min to 350 °C, hold for 35 min, and finally air-cool to room temperature; S102: Ultrasonically treat the carbon nanotubes processed in S101 and the ball milling liquid in a weight ratio of 3:5. After the ultrasonic treatment is completed, carry out suction filtration and drying to obtain the supported ball milling agent.

[0043] In this example, the ultrasonic power for the ultrasonic treatment is 400 W, and the ultrasonic treatment is carried out for 1 h.

[0044] The ball milling liquid in this example includes the following components by weight: 5 parts of kaolin, 6 parts of lanthanum chloride solution, 3 parts of aluminum borate whiskers, 2 parts of bismuth titanate, and 0.7 part of urea solution.

[0045] In this example, the mass fraction of the urea solution is 6%; the mass fraction of the lanthanum chloride solution is 5%.

[0046] Example 3 A preparation method of anisaldehyde in this example includes the following steps: Step 1: Add xylene and the catalyst of modified cobalt hydroxide into the reaction kettle, slowly drop glacial acetic acid into the reaction kettle, control the temperature at 95 °C, and maintain the total reflux state for 2 h; Step 2: Filter and separate the catalyst and the mother liquor through a filter press. After the mother liquor stands, separate the oil phase and the water phase; Step 3: Transfer the oil phase to the distillation kettle. The materials in the kettle are vaporized after being heated by the heat transfer oil. The materials in the kettle are vaporized after being heated by the heat transfer oil, and the vapor phase rises and enters the distillation column; Step 4: Obtain anisaldehyde through distillation in the distillation column.

[0047] The process steps of distillation in step 4 of this embodiment are: After the gas phase at the top of the tower is condensed by the top condenser, it enters the reflux ratio distributor. After the distribution, a part of the material refluxes from the top of the distillation tower. The rising steam and the refluxed liquid transfer heat and mass in the distillation tower to form a stable concentration gradient and temperature gradient. The other stream of material is cooled by the top cooler according to the sampling results and then collected into different fraction tanks. When the top temperature of the distillation tower rises and stabilizes at 145℃, close the reflux ratio distributor for full reflux operation, take samples of the top fraction for inspection, and start to extract the product fraction when the product fraction is qualified. Then check the bottom liquid level and the temperature changes of the tower sections. When the bottom liquid level is ≤250mm or the top temperature starts to rise, the single batch distillation is completed.

[0048] The preparation method of the modified cobalt hydroxide catalyst of this embodiment is: S01: Preparation of modified composite liquid: S01a: 3 parts by weight of sodium dodecylbenzene sulfonate solution and 2 parts by weight of silane coupling agent KH550 are added to 6.5 parts by weight of 4% yttrium nitrate solution, and then 4 parts by weight of nano titanium dioxide are added and stirred to obtain a first modified solution; S01b: 2.5 parts by weight of cerium oxide and 2 parts by weight of aluminum oxide are mixed and added into 6.5 parts by weight of dopamine hydrochloride solution and mixed thoroughly to obtain a second modified solution; S01c: fully stirring the first modified liquid and the second modified liquid in a weight ratio of 3:5 to obtain a modified composite liquid; S02: cobalt hydroxide is preheated at 57.5°C for 1 hour, and the preheated cobalt hydroxide is added to the modified composite liquid at a weight ratio of 2:4.5, and stirred for modification treatment. After the stirring is completed, a modified cobalt hydroxide liquid is obtained; S03: The modified cobalt hydroxide solution and the loaded ball milling agent are mixed in a weight ratio of 5:3, and the mixture is ball milled at a speed of 1250 r / min for 2 h. After the ball milling is completed, the mixture is filtered and dried to obtain a modified cobalt hydroxide catalyst.

[0049] The mass fraction of the dopamine hydrochloride solution in this embodiment is 5.5%; the mass fraction of the sodium dodecylbenzene sulfonate solution is 3.5%.

[0050] The stirring speed of the stirring modification treatment in this embodiment is 600 r / min, and the stirring is for 1 hour.

[0051] The preparation method of the loaded ball mill of this embodiment is: S101: irradiating the carbon nanotubes in a proton irradiation box for 1 hour at an irradiation power of 450 W, and obtaining irradiated carbon nanotubes after the irradiation is completed; The irradiated carbon nanotubes are reheated and improved. The specific improvement method is as follows: First, heat it up to 225°C at a rate of 3.5°C / min, hold for 15 min, then heat it up to 350°C at a rate of 2°C / min, hold for 35 min, and finally air-cool it to room temperature; S102: Ultrasonically treat the carbon nanotubes treated in S101 and the ball milling liquid in a weight ratio of 3:5. After the ultrasonic treatment is completed, filter by suction and dry to obtain the supported ball milling agent.

[0052] In this embodiment, the ultrasonic power of the ultrasonic treatment is 375 W and the ultrasonic treatment lasts for 1 h.

[0053] The ball milling liquid in this embodiment includes the following components by weight: 4 parts of kaolin, 5 parts of lanthanum chloride solution, 2.5 parts of aluminum borate whiskers, 1.5 parts of bismuth titanate, and 0.6 part of urea solution.

[0054] In this embodiment, the mass fraction of the urea solution is 5%; the mass fraction of the lanthanum chloride solution is 3.5%.

[0055] Comparative Example 1 The difference from Example 3 is that the catalyst of modified cobalt hydroxide is replaced by cobalt hydroxide.

[0056] Comparative Example 2 The difference from Example 3 is that the modified composite liquid is not added during the preparation of the catalyst of modified cobalt hydroxide.

[0057] Comparative Example 3 The difference from Example 3 is that the first modified liquid is not added to the modified composite liquid.

[0058] Comparative Example 4 The difference from Example 3 is that nano-titanium dioxide is not added to the first modified liquid, and the yttrium nitrate solution is replaced by water.

[0059] Comparative Example 5 The difference from Example 3 is that the second modified liquid is not added to the modified composite liquid.

[0060] Comparative Example 6 The difference from Example 3 is that cerium oxide and alumina are not added to the second modified liquid.

[0061] Comparative Example 7 The difference from Example 3 is that the supported ball milling agent is not added during the preparation of the catalyst of modified cobalt hydroxide.

[0062] Comparative Example 8 The difference from Example 3 is that the carbon nanotubes treated in S101 are not added to the supported ball milling agent.

[0063] Comparative Example 9 The difference from Example 3 is that the carbon nanotubes treated in S101 are not subjected to thermal improvement treatment.

[0064] Comparative Example 10 The difference from Example 3 is that the ball milling liquid treatment was not added to the loaded ball milling agent.

[0065] The conversion rate of anisaldehyde and the selectivity of anisaldehyde in Examples 1 - 3 and Comparative Examples 1 - 10 were routinely tested. At the same time, the catalysts of Examples 1 - 3 and Comparative Examples 1 - 10 were placed under 2% hydrochloric acid mist conditions for 12 h, and then placed under 5% sodium hydroxide mist conditions for 24 h to test the stability of the product. The test results are as follows;

[0066] It can be seen from Comparative Examples 1 - 10 and Examples 1 - 3 that; The product of Example 3 has excellent anisaldehyde conversion rate and anisaldehyde selectivity. At the same time, the catalyst of the product has excellent stability in an acidic and alkaline corrosion environment; It can be seen from Comparative Examples 1 - 10 and Example 3 that when the modified cobalt hydroxide catalyst is replaced with cobalt hydroxide, the performance of the product deteriorates significantly, especially in an acidic and alkaline corrosion environment, and the performance stability deteriorates significantly; In addition, when the modified composite liquid treatment is not added during the preparation of the modified cobalt hydroxide catalyst, and when the loaded ball milling agent is not added during the preparation of the modified cobalt hydroxide catalyst, the performance of the product shows an obvious deteriorating trend. The performance effect of the modified cobalt hydroxide catalyst prepared with the modified composite liquid and the loaded ball milling agent of the present invention is significant; When the first modified liquid is not added to the modified composite liquid, nano - titanium dioxide is not added to the first modified liquid, the yttrium nitrate solution is replaced with water, the second modified liquid is not added to the modified composite liquid, cerium oxide and alumina are not added to the second modified liquid, the carbon nanotubes treated with S101 are not added to the loaded ball milling agent, the carbon nanotubes treated with S101 are not subjected to heat improvement treatment, and the ball milling liquid treatment is not added to the loaded ball milling agent, the performance of the product shows a deteriorating trend to varying degrees. The performance effect of the modified composite liquid obtained by the specific methods of the first modified liquid and the second modified liquid of the present invention, as well as the loaded ball milling agent obtained by the carbon nanotubes treated with S101 and the ball milling liquid treatment, is the most significant. Replacing with other methods is not as obvious as the effect of the present invention. At the same time, when the ball milling liquid treatment is not added to the loaded ball milling agent, the performance stability of the product also shows a more obvious deteriorating trend.

[0067] Based on the fact that the ball milling liquid has a great influence on the performance of the product, further research was carried out on this: The ball milling liquid comprises the following components by weight: 4 parts of kaolin, 5 parts of lanthanum chloride solution, 2.5 parts of aluminum borate whiskers, 1.5 parts of bismuth titanate, and 0.6 parts of urea solution.

[0068] The mass fraction of the urea solution in this embodiment is 5%; the mass fraction of the lanthanum chloride solution is 3.5%.

[0069] Experimental Example 1 The only difference from Example 3 is that kaolin is not added to the ball milling liquid.

[0070] Experimental Example 2 The only difference from Example 3 is that aluminum borate whiskers are not added to the ball milling liquid.

[0071] Experimental Example 3 The only difference from Example 3 is that bismuth titanate is not added to the ball milling liquid.

[0072] Experimental Example 4 The only difference from Example 3 is that the urea solution is not added to the ball milling liquid.

[0073] Experimental Example 5 The only difference from Example 3 is that the lanthanum chloride solution is not added to the ball milling liquid.

[0074] The product performance tests of Experimental Examples 1 - 5 are as follows:

[0075] It can be seen from Experimental Examples 1 - 5 that when kaolin is not added to the ball milling liquid, the change trend of the product performance stability is relatively large; when aluminum borate whiskers are not added to the ball milling liquid, the change trend of the product performance is relatively large under conventional conditions; and when bismuth titanate, the urea solution, or the lanthanum chloride solution is not added to the ball milling liquid, the product performance shows a deteriorating trend. The product performance effect of the ball milling liquid obtained by the specific method of the present invention is the most significant, and the effect of using other methods instead is not as obvious as that of the present invention.

[0076] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above - mentioned exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, in any aspect, the embodiments should be regarded as exemplary and non - restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention.

[0077] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for preparing anisaldehyde, characterized in that, The following steps are involved: Step 1: Add xylene and modified cobalt hydroxide catalyst into the reactor, slowly add glacial acetic acid to the reactor, control the temperature at 80-110 degrees, and maintain full reflux for 2 hours; Step 2: filtering the catalyst and the mother liquor through a filter press, and separating the oil phase and the water phase after the mother liquor is allowed to stand; Step 3: The oil phase is pumped into the distillation kettle, and the material in the kettle is vaporized after being heated by the heat transfer oil. The material in the kettle is vaporized after being heated by the heat transfer oil, and the vapor phase rises and enters the distillation tower; Step 4: obtain anisaldehyde by distillation through a distillation tower.

2. A method for preparing anisaldehyde according to claim 1, characterized in that, The process steps of distillation in step 4 are: After the gas phase at the top of the tower is condensed by the top condenser, it enters the reflux ratio distributor. After the distribution, a part of the material refluxes from the top of the distillation tower. The rising steam and the refluxed liquid transfer heat and mass in the distillation tower to form a stable concentration gradient and temperature gradient. The other stream of material is cooled by the top cooler according to the sampling results and then collected into different fraction tanks. When the top temperature of the distillation tower rises and stabilizes at 130℃~160℃, close the reflux ratio distributor for full reflux operation, take samples for inspection of the top fraction, and start to extract the product fraction when the product fraction is qualified. Then check the bottom liquid level and the temperature changes of the tower sections. When the bottom liquid level is ≤250mm or the top temperature starts to rise, the single batch distillation is completed.

3. A method for preparing anisaldehyde according to claim 1, characterized in that, The preparation method of the modified cobalt hydroxide catalyst is: S01: Preparation of modified composite liquid: S01a: Add 2 to 4 parts by weight of sodium dodecylbenzene sulfonate solution and 1 to 3 parts by weight of silane coupling agent KH550 to 5 to 8 parts by weight of 4% yttrium nitrate solution, then add 3 to 5 parts by weight of nano titanium dioxide, stir evenly, and obtain a first modified solution; S01b: 2 to 3 parts by weight of cerium oxide and 1 to 3 parts by weight of aluminum oxide are mixed into 5 to 8 parts by weight of dopamine hydrochloride solution and mixed thoroughly to obtain a second modified solution; S01c: fully stirring the first modified liquid and the second modified liquid in a weight ratio of 3:5 to obtain a modified composite liquid; S02: Cobalt hydroxide is preheated at 55-60°C for 1h, and the preheated cobalt hydroxide is added to the modified composite liquid in a weight ratio of 2:(4-5) and stirred for modification. After the stirring is completed, a modified cobalt hydroxide liquid is obtained; S03: The modified cobalt hydroxide solution and the loaded ball milling agent are mixed in a weight ratio of 5:3, and the ball milling is performed at a ball milling speed of 1000-1500 r / min for 2 hours. After the ball milling is completed, the modified cobalt hydroxide catalyst is obtained by suction filtration and drying.

4. A method for preparing anisaldehyde according to claim 3, characterized in that, The mass fraction of the dopamine hydrochloride solution is 4-7%; the mass fraction of the sodium dodecylbenzenesulfonate solution is 2-5%.

5. A method for preparing anisaldehyde according to claim 3, characterized in that, The stirring speed of the stirring modification treatment is 550-750 r / min, and the stirring is for 1 hour.

6. A method for preparing anisaldehyde according to claim 3, characterized in that, The preparation method of the loaded ball mill is as follows: S101: irradiating the carbon nanotubes in a proton irradiation box for 1 hour at an irradiation power of 400 to 500 W, and obtaining irradiated carbon nanotubes after the irradiation is completed; The irradiated carbon nanotubes are reheated and improved. The specific improvement method is as follows: First, heat to 220-230°C at a rate of 2-5°C / min, keep warm for 15 minutes, then heat to 350°C at a rate of 1-3°C / min, keep warm for 35 minutes, and finally air cool to room temperature; S102: The carbon nanotubes treated in S101 and the ball milling solution are subjected to ultrasonic treatment at a weight ratio of 3:

5. After the ultrasonic treatment is completed, the mixture is filtered and dried to obtain a loaded ball milling agent.

7. A method for preparing anisaldehyde according to claim 6, characterized in that, The ultrasonic power of the ultrasonic treatment was 350-400W, and the ultrasonic treatment lasted for 1 hour.

8. A method for preparing anisaldehyde according to claim 6, characterized in that, The ball milling liquid comprises the following components in parts by weight: 3 to 5 parts of kaolin, 4 to 6 parts of lanthanum chloride solution, 2 to 3 parts of aluminum borate whiskers, 1 to 2 parts of bismuth titanate and 0.5 to 0.7 parts of urea solution.

9. A method for preparing anisaldehyde according to claim 8, characterized in that, The mass fraction of the urea solution is 4-6%; the mass fraction of the lanthanum chloride solution is 2-5%.

Images