Method and device for producing anilino acetate

Abstract

The invention provides an anilino acetate production method and device, and the method comprises the following steps: adding bottom water into a material melting tank, adding aniline acetonitrile into the material melting tank, and heating to 40-50 DEG C to obtain an aniline acetonitrile suspension; adding the aniline acetonitrile suspension into a hydrolysis kettle, then adding liquid caustic soda, heating while stirring, controlling the reaction temperature to be 50-60 DEG C, stirring and reacting for 3-4 hours, heating to reflux, and reacting for 2-3 hours to obtain a reaction solution; heating and concentrating the reaction solution to obtain a concentrated solution; and cooling and crystallizing the concentrated solution, separating crystals, and drying the crystals to obtain anilino acetate. According to the method disclosed by the invention, the hydrolysis process is divided into two stages, namely a reaction at a low temperature of 50-60 DEG C and a reflux reaction, so that the time of the reflux reaction is shortened, and the defect that the energy consumption is high when aniline acetonitrile is directly hydrolyzed to produce anilinoacetate in a traditional reflux mode can be effectively avoided.

Description

Technical Field

[0001] The present application relates to the synthesis technology of dye intermediates, and particularly relates to a production method and device for aniline acetate. Background Art

[0002] Aniline acetate, also known as N-phenylglycine salt, is an important chemical synthesis raw material and an important intermediate for synthesizing indigo dyes. The main synthesis methods include the aniline-chloroacetic acid condensation method and the aniline acetonitrile hydrolysis method. Since the aniline-chloroacetic acid condensation method easily produces a large amount of iron-containing wastewater, this wastewater is difficult to treat and the treatment process causes great pollution. This method has now been basically phased out. The aniline acetonitrile hydrolysis method is an improved method for synthesizing aniline acetate. This reaction uses aniline acetonitrile as a substrate and reacts with liquid alkali (an aqueous solution of sodium hydroxide or potassium hydroxide) by heating. However, the traditional aniline acetonitrile hydrolysis method requires heating aniline acetonitrile and liquid alkali to reflux for about 8 hours. This process has a long reaction time, and the long-term reflux consumes a huge amount of energy. Summary of the Invention

[0003] The present application provides a production method and device for aniline acetate to solve the problem of large energy consumption caused by the long reflux reaction time when preparing phenylacetic acid salt by hydrolyzing aniline acetonitrile as described above.

[0004] In a first aspect, the present application provides a production method for aniline acetate, including the following steps: Add bottom water to the chemical feeding tank, put aniline acetonitrile into the chemical feeding tank, and heat to 40 - 50 °C to obtain an aniline acetonitrile suspension; Put the aniline acetonitrile suspension into the hydrolysis kettle, then add liquid alkali, raise the temperature under stirring, control the reaction temperature at 50 - 60 °C, stir and react for 3 - 4 hours, then raise the temperature to reflux and react for 2 - 3 hours to obtain a reaction solution; Raise the temperature of the reaction solution for concentration to obtain a concentrated solution; Cool the concentrated solution for crystallization, separate the crystals after crystallization, and dry the crystals to obtain aniline acetate.

[0005] The present application provides a production method for aniline acetate. The method of the present application divides the hydrolysis process into two stages: a low-temperature reaction at 50 - 60 °C and a reflux reaction, shortening the reflux reaction time, and effectively avoiding the disadvantage of large energy consumption when hydrolyzing aniline acetonitrile to produce aniline acetate by directly using the reflux method as in the traditional method.

[0006] Optionally, a catalyst is also added to the hydrolysis kettle; The catalyst is an aqueous solution of potassium iodide with iodine, and the addition amount of the catalyst is 5 - 10% of the weight of the aniline acetonitrile suspension; The catalyst is added to the aniline acetonitrile suspension before adding the liquid alkali.

[0007] Optionally, the catalyst is configured as follows: By weight, take 10 - 12 parts of iodine and 40 - 50 parts of potassium iodide, mix them, add them to 100 parts of water, and stir until the solid is completely dissolved to obtain the product.

[0008] Optionally, the molar ratio of aniline acetonitrile to the alkali in liquid alkali is 1∶(1.05 - 1.15).

[0009] Optionally, the liquid alkali is an aqueous solution of sodium hydroxide or potassium hydroxide, and the concentration is 45 - 50%.

[0010] Optionally, the addition amount of bottom water is 5 - 15% of the volume of aniline acetonitrile.

[0011] In a second aspect, the present application provides an aniline acetate production device, which is applied to the aniline acetate production method according to any one of the above first aspects, and includes a chemical feeding tank, a hydrolysis kettle, a crystallization kettle, a dryer, and a dust collector connected in series in sequence, and an aniline acetate storage tank; The hydrolysis kettle is also connected to an ammonia gas collection tank and a condensate storage tank respectively through a condenser; The hydrolysis kettle is also connected to a liquid alkali high-level tank and a catalyst metering pump respectively; The crystallization kettle is also connected to a filtrate storage tank, and the filtrate storage tank is also connected to the hydrolysis kettle.

[0012] Optionally, the ammonia gas collection tank is also connected to an ammonia gas drying device and an ammonia gas absorption device respectively; The ammonia gas drying device is also connected to an ammonia gas pipeline, and the ammonia gas absorption device is also connected to the condensate storage tank and an ammonia water storage tank respectively.

[0013] Optionally, the crystallization kettle includes a cylinder body; The upper end of the cylinder body is sealed by an upper head, and the lower end is sealed by a lower head; a stirrer is arranged in the cylinder body through the upper head; A filter screen is arranged in the lower head; The lower head is connected to a filtrate bin through a pipeline with a valve, and the top of the filtrate bin is connected to a vacuum pump.

[0014] Optionally, the stirrer includes a stirring rod and vertically arranged stirring scraping plates, and the stirring rod and the stirring scraping plates are connected by a connecting plate; One side of the stirring scraping plate is connected to the connecting plate, and the other side abuts against the inner side wall of the cylinder body and can slide along the inner side wall of the cylinder body.

[0015] The present application provides an aniline acetate production device. By setting a crystallization kettle to crystallize the synthesized reaction solution, and at the same time setting a filtrate storage tank connected to a hydrolysis kettle, the mother liquor filtrate after crystallization can be recycled to the hydrolysis kettle to participate in the reaction, effectively reducing the waste of materials during the reaction. At the same time, by setting a condenser and an ammonia gas collection tank and a condensate storage tank connected to the condenser, the ammonia gas and moisture evaporated during the reaction can be recycled and stored. While reducing resource waste, it can also reduce the discharge of wastewater during the reaction, having the beneficial effect of protecting the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 Schematic diagram of an aniline acetate production device provided by an embodiment of the present application; Figure 2 Schematic diagram of an aniline acetate production device provided by another embodiment of the present application; Figure 3 Schematic diagram of the structure of a crystallization kettle provided by an embodiment of the present application; Figure 4 Schematic diagram of the structure of a stirrer provided by an embodiment of the present application.

[0018] Description of the reference numerals in the drawings: 1, chemical feeding tank; 2, hydrolysis kettle; 3, crystallization kettle; 4, dryer; 5, ammonia gas collection tank; 6, condensate storage tank; 7, filtrate storage tank; 21, condenser; 22, liquid alkali high-level tank; 23, catalyst metering pump; 31, cylinder body; 32, upper head; 33, lower head; 34, stirrer; 35, filter screen; 36, filtrate bin; 37, vacuum pump; 41, dust collector; 42, phenylglycine acetate storage tank; 50, ammonia gas pipeline; 51, ammonia gas drying device; 52, ammonia gas absorption device; 53, ammonia water storage tank; 341, stirring rod; 342, stirring scraper; 343, connecting plate. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following clearly and completely describes the technical solutions in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts also belong to the scope of protection of the present application.

[0020] In a first aspect, the present application provides a method for producing anilinoacetate, comprising the following steps: Add bottom water to a chemical feeding tank, put aniline acetonitrile into the chemical feeding tank, and heat to 40 - 50 °C to obtain an aniline acetonitrile suspension; Put the aniline acetonitrile suspension into a hydrolysis kettle, add liquid alkali, raise the temperature with stirring, control the reaction temperature at 50 - 60 °C, stir and react for 3 - 4 h, then raise the temperature to reflux, and react for 2 - 3 h to obtain a reaction solution; Raise the temperature of the reaction solution for concentration to obtain a concentrated solution; Cool the concentrated solution for crystallization, separate the crystals, and then dry the crystals to obtain anilinoacetate.

[0021] The present application provides a method for producing anilinoacetate. The method of the present application divides the hydrolysis process into two stages: a low - temperature reaction at 50 - 60 °C and a reflux reaction, shortening the reflux reaction time, and effectively avoiding the disadvantage of large energy consumption when directly using the reflux method to hydrolyze aniline acetonitrile to produce anilinoacetate in the traditional way.

[0022] Optionally, a catalyst is also added to the hydrolysis kettle; The catalyst is an aqueous solution of potassium iodide iodide, and the addition amount of the catalyst is 5 - 10% of the weight of the aniline acetonitrile suspension; The catalyst is added to the aniline acetonitrile suspension before adding the liquid alkali.

[0023] In the present application, the catalyst is not consumed during the reaction, so its dosage is controlled at 5 - 10% of the weight of the aniline acetonitrile suspension.

[0024] Optionally, the catalyst is prepared according to the following method: By weight, take 10 - 12 parts of iodine and 40 - 50 parts of potassium iodide, mix them, and add them to 100 parts of water, stir until the solids are completely dissolved to obtain.

[0025] In the present application, the catalyst is an aqueous solution of potassium iodide iodide, which can promote the reaction rate between the hydroxyl group and the cyano carbon during the reaction, thereby increasing the reaction rate. In addition, it can also reduce the generation of by - product amide in the reaction.

[0026] In the present application, the hydrolysis process after adding the catalyst is specifically as follows: Put the aniline acetonitrile suspension into a hydrolysis kettle, add 5 - 10% of the catalyst based on the weight of the aniline acetonitrile suspension, then add liquid alkali, raise the temperature with stirring, control the reaction temperature at 50 - 60 °C, stir and react for 0.5 - 1 h, then raise the temperature to reflux, and react for 1 - 2 h to obtain a reaction solution.

[0027] Optionally, the molar ratio of aniline acetonitrile to the alkali in the liquid alkali is 1∶(1.05 - 1.15).

[0028] In this application, the addition of slightly excessive liquid caustic can effectively promote the conversion of phenylacetonitrile, making the reaction of phenylacetonitrile complete and reducing the waste of the substrate.

[0029] Optionally, the liquid caustic is an aqueous solution of sodium hydroxide or potassium hydroxide, and the concentration is 45 - 50%.

[0030] In this application, using a liquid caustic with a higher concentration can reduce the amount of solvent used, and the relatively concentrated liquid caustic also has the effect of increasing the reaction rate.

[0031] Optionally, the addition amount of bottom water is 5 - 15% of the volume of phenylacetonitrile.

[0032] In this application, the addition of bottom water can play the role of heat conduction and dilution. The addition amount of bottom water is 5 - 15% of the volume of phenylacetonitrile, avoiding excessive influence on the concentration of phenylacetonitrile in the reaction and thus affecting the yield.

[0033] In the second aspect, as Figure 1 shown, this application provides a phenylglycine salt production device, which is applied to the phenylglycine salt production method of any item in the above first aspect, and includes a material melting tank 1, a hydrolysis kettle 2, a crystallization kettle 3, a dryer 4, a dust collector 41 and a phenylglycine salt storage tank 42 connected in series in sequence; The hydrolysis kettle 2 is also connected to an ammonia collection tank 5 and a condensate storage tank 6 through a condenser 21 respectively; The hydrolysis kettle 2 is also connected to a liquid caustic high-level tank 22 and a catalyst metering pump 23 respectively; The crystallization kettle 3 is also connected to a filtrate storage tank 7, and the filtrate storage tank 7 is also connected to the hydrolysis kettle 2.

[0034] When the device of the present application is in use, bottom water is added to the chemical feed tank 1, and aniline acetonitrile is added to the chemical feed tank 1. It is heated to 40-50°C under stirring, and the heated aniline acetonitrile suspension is added to the hydrolysis kettle 2 through a corresponding transfer pump. Under stirring, a catalyst (iodine solution in this application) is added to the hydrolysis kettle 2 through a catalyst metering pump 23. After stirring for 5-10 minutes, liquid alkali (sodium hydroxide or potassium hydroxide aqueous solution with a concentration of 45-50% in this application) in the liquid alkali high-level tank 22 is added to the hydrolysis kettle 2 according to the measurement. The reaction temperature is controlled at 50-60°C under stirring and the reaction is carried out for 3-4 hours, and then the temperature is raised to reflux (100°C ± 2°C). In this application, a condenser is provided on the hydrolysis kettle 2, so the water vapor evaporated during the reflux process will be condensed and then refluxed into the kettle. Since ammonia gas is generated during the reaction process, the ammonia gas will evaporate from the hydrolysis kettle 2 and is transferred into the ammonia gas collection tank 5 for temporary storage after the water in it is condensed by the condenser 21 (since the evaporated ammonia gas has been condensed by the condenser on the hydrolysis kettle 2, a low-flow heat exchange medium can be introduced into the condenser 21 at this time). The condensed water is stored in the condensate storage tank 6 for subsequent use in absorbing ammonia gas.

[0035] After the reaction is completed, the reactants in the hydrolysis kettle 2 are heated up. At this time, the supply of condensed water to the condenser on the hydrolysis kettle 2 is stopped, and the solvent in the kettle is evaporated to concentrate the reaction solution (heating is stopped when crystals precipitate in the reaction kettle). The evaporated solvent (mainly water and ammonia) is condensed by the condenser 21. Part of the ammonia is stored in the ammonia gas collection tank 5, and the condensate is transferred to the condensate storage tank 6 for storage. Since ammonia is easily soluble in water, the actually condensed condensate is a low-concentration ammonia water and can be used as the absorption liquid for ammonia absorption.

[0036] The concentrated liquid obtained by concentrating in the hydrolysis kettle 2 is promptly transferred to the crystallization kettle 3 while it is hot for crystallization. During the crystallization process, circulating water is introduced into the jacket of the crystallization kettle 3 for cooling, and at the same time, the concentrated liquid is stirred to avoid the formation of large crystals. After crystallization is completed, the mixture is filtered, and the obtained filtrate, which still contains a small amount of phenylglycine salt and catalyst, is transferred to the filtrate storage tank 7 for temporary storage and can be transferred back to the hydrolysis kettle 2 to continue participating in the reaction for recycling.

[0037] The filter cake obtained by filtration is transferred to the dryer 4 for drying (the dryer uses hot air drying, or indirect heat exchange drying, or microwave drying). The dusty tail gas generated during the drying process is transferred to the dust collector 41 through a corresponding fan for dust removal, and the dust-removed gas enters the subsequent tail gas treatment equipment for treatment. The dust collected by the dust-removed gas, which is also the dried phenylglycine salt, is combined with the phenylglycine salt dried in the dryer 4 and stored in the phenylglycine salt storage tank.

[0038] The present application provides an aniline acetate production device. By setting a crystallization kettle 3 to crystallize the synthesized reaction solution, and at the same time setting a filtrate storage tank 7 connected to a hydrolysis kettle 2, the mother liquor filtrate after crystallization can be recycled to the hydrolysis kettle 2 to participate in the reaction, which can effectively reduce the waste of materials during the reaction. At the same time, by setting a condenser 21 and an ammonia collection tank 5 and a condensate storage tank 6 connected to the condenser 21, the ammonia and moisture evaporated during the reaction can be recycled and stored. While reducing resource waste, it can also reduce the discharge of wastewater during the reaction, having the beneficial effect of protecting the environment.

[0039] As Figure 2 shown, optionally, the ammonia collection tank 5 is also respectively connected to an ammonia drying device 51 and an ammonia absorption device 52; The ammonia drying device 51 is also connected to an ammonia pipeline 50, and the ammonia absorption device 52 is also respectively connected to the condensate storage tank 6 and an ammonia water storage tank 53.

[0040] There will still be a small amount of moisture in the ammonia stored in the ammonia collection tank 5. In the subsequent alkali fusion process, anhydrous ammonia is required to react with sodium to prepare sodium amide. At this time, a part of the ammonia can be passed through the ammonia drying device 51 (such as a drying tower filled with slaked lime) to remove the moisture in it to obtain dry ammonia, and the dry ammonia is recycled to the ammonia pipeline 50 for use in the reactions of subsequent processes.

[0041] Some processes in the factory also require ammonia water. At this time, the ammonia in the ammonia collection tank 5 can be introduced into the ammonia absorption device 52 (such as a spray tower), and water or the condensate stored in the condensate storage tank 6 is used as an absorbent to absorb the ammonia to make ammonia water, which is stored in the ammonia water storage tank 53.

[0042] As Figure 3 shown, optionally, the crystallization kettle 3 includes a cylinder body 31; The upper end of the cylinder body 31 is sealed by an upper head 32, and the lower end is sealed by a lower head 33; a stirrer 34 is arranged in the cylinder body 31 through the upper head 32; A filter screen 35 is arranged in the lower head 33; The lower head 33 is connected to a filtrate bin 36 through a pipeline with a valve, and the top of the filtrate bin 36 is connected to a vacuum pump 37.

[0043] In this application, during the crystallization process, circulating water is introduced into the jacket of the crystallization kettle 3 for cooling. Meanwhile, the stirrer 34 is turned on to stir the concentrated liquid to avoid the formation of large crystals. After the crystallization ends, the stirring is stopped. The valve on the pipeline connecting the lower head 33 and the filtrate tank 36 is opened. Meanwhile, the vacuum pump 37 is turned on to evacuate the filtrate tank 36 to create a negative pressure state. Due to the filtering and supporting effects of the filter screen 35, the precipitated crystals are intercepted above the filter screen 35, while the filtrate flows into the filtrate tank 36. Due to the suction of the vacuum pump 37, the filtration process can be accelerated. After the filtration ends, the corresponding vent valve on the filtrate tank 36 is opened to break the vacuum, and the vacuum pump 37 is turned off. The pipeline connection between the lower head 33 and the filtrate tank 36 is disconnected (the two can be connected to the pipeline by a quick-connect interface). The lower head 33 is opened (one side of the lower head 33 is rotatably connected to the cylinder body 31, and the other side is connected by a quick-connect method such as clamping). The filter cake in the lower head 33 is transferred to the dryer 4 for drying (the dryer uses hot air drying, or wall heat exchange drying, or microwave drying).

[0044] As Figure 4 shown, optionally, the stirrer 34 includes a stirring rod 341 and a vertically arranged stirring scraper 342. The stirring rod 341 and the stirring scraper 342 are connected by a connecting plate 343; One side of the stirring scraper 342 is connected to the connecting plate 343, and the other side is in contact with and arranged against the inner side wall of the cylinder body 31 and can slide along the inner side wall of the cylinder body 31.

[0045] In this application, after the large filter cake in the kettle is transferred out through the lower head 33, a small amount of crystals still adhere to the kettle wall. At this time, the stirrer 34 is turned on, and the stirring scraper 342 is used to scrape off the crystals adhering to the kettle wall.

[0046] A phenylglycine salt production device has the following working process: In use, add bottom water to the chemical feed tank 1, add aniline acetonitrile to the chemical feed tank 1, then heat it to 40 - 50°C with stirring. Add the heated aniline acetonitrile suspension to the hydrolysis kettle 2 through the corresponding transfer pump. With stirring, add the catalyst (iodine solution in this application) to the hydrolysis kettle 2 through the catalyst metering pump 23. Stir for 5 - 10 minutes and then add the liquid alkali (sodium hydroxide or potassium hydroxide aqueous solution with a concentration of 45 - 50% in this application) in the liquid alkali elevated tank 22 to the hydrolysis kettle 2 according to the measurement. Control the reaction temperature at 50 - 60°C with stirring and react for 3 - 4 hours, then raise the temperature to reflux (100°C ± 2°C). In this application, a condenser is provided on the hydrolysis kettle 2, so the water vapor evaporated during the reflux process will be condensed and then refluxed into the kettle. Since ammonia gas is generated during the reaction process, the ammonia gas will evaporate from the hydrolysis kettle 2 and be transferred to the ammonia gas collection tank 5 for temporary storage after the water in it is condensed by the condenser 21 (since the evaporated ammonia gas has passed through the condensation of the condenser on the hydrolysis kettle 2, a low-flow heat exchange medium can be introduced into the condenser 21 at this time). The condensed water is stored in the condensate storage tank 6 for subsequent use in absorbing ammonia gas.

[0047] There will still be a small amount of water in the ammonia gas stored in the ammonia gas collection tank 5. In the subsequent alkali fusion process, anhydrous ammonia is needed to react with sodium to prepare sodium amide. At this time, a part of the ammonia gas can be passed through the ammonia gas drying device 51 (such as a drying tower filled with slaked lime) to remove the water in it to obtain dry ammonia gas, and the dry ammonia gas is recovered into the ammonia gas pipeline for use in the reaction of subsequent processes.

[0048] Some processes in the factory also need ammonia water. At this time, the ammonia gas in the ammonia gas collection tank 5 can be passed into the ammonia gas absorption device 52 (such as a spray tower), and water or the condensate stored in the condensate storage tank 6 is used as the absorbent to absorb the ammonia gas to make ammonia water, which is stored in the ammonia water storage tank 53.

[0049] After the reaction is completed, raise the temperature of the reactants in the hydrolysis kettle 2. At this time, stop supplying condensed water to the condenser on the hydrolysis kettle 2, evaporate the solvent in the kettle, and concentrate the reaction solution (stop heating when crystals precipitate in the reaction kettle). The evaporated solvent (mainly water and ammonia) is condensed by the condenser 21. Part of the ammonia is stored in the ammonia gas collection tank 5, and the condensate is transferred to the condensate storage tank 6 for storage. Since ammonia gas is easily soluble in water, the actually condensed condensate is low-concentration ammonia water, which can be used as the absorbent in the ammonia gas absorption device 52.

[0050] Transfer the concentrated liquid obtained by concentration in the hydrolysis kettle 2 to the crystallization kettle 3 in time while it is still hot for crystallization. During the crystallization process, circulating water is introduced into the jacket of the crystallization kettle 3 for cooling. At the same time, the stirrer 34 is turned on to stir the concentrated liquid to avoid the formation of large crystals. After the crystallization is completed, the stirring is stopped, and the valve on the pipeline connecting the lower head 33 and the filtrate tank 36 is opened. At the same time, the vacuum pump 37 is turned on to evacuate the filtrate tank 36 to form a negative pressure state. Due to the filtering and supporting effect of the filter screen 35, the precipitated crystals are intercepted above the filter screen 35, while the filtrate flows into the filtrate tank 36. Due to the suction of the vacuum pump 37, the filtering process can be accelerated. After the filtering is completed, the corresponding vent valve on the filtrate tank 36 is opened to break the vacuum, and the vacuum pump 37 is turned off. The pipeline connection between the lower head 33 and the filtrate tank 36 is disconnected (the two can be connected to the pipeline by a quick-connect interface), and the lower head 33 is opened (one side of the lower head 33 is rotatably connected to the cylinder body 31, and the other side is connected by a quick-connect method such as clamping), and the filter cake in the lower head 33 is transferred to the dryer 4 for drying (the dryer is dried by hot air drying or indirect heat exchange drying or microwave drying). After the large filter cake in the kettle is transferred out through the lower head 33, there is still a small amount of crystallization adhering to the kettle wall. At this time, the stirrer 34 is turned on, and the stirring scraper 342 is used to scrape off the crystallization adhering to the kettle wall.

[0051] The dust-containing tail gas generated during the drying process is transferred to the dust collector 41 through the corresponding fan for dust removal, and the dust-removed gas enters the subsequent tail gas treatment equipment for treatment. The dust collected by the dust-removed gas is also the dried phenylglycine salt, which is combined with the phenylglycine salt dried in the dryer 4 and stored in the phenylglycine salt storage tank.

[0052] The filtrate collected in the filtrate tank 36 still contains a small amount of phenylglycine salt and catalyst, which can be transferred to the hydrolysis kettle 2 to continue to participate in the reaction for recovery. Specific embodiments

[0053] Example 1 S101. Add bottom water accounting for 5% of the volume of phenylacetonitrile to the chemical feeding tank, put phenylacetonitrile into the chemical feeding tank, and heat it to 40-50 °C to obtain a phenylacetonitrile suspension.

[0054] S102. Pour the phenylacetonitrile suspension into the hydrolysis kettle, then add a sodium hydroxide aqueous solution with a concentration of 45%, raise the temperature with stirring, control the reaction temperature at 50-60 °C, stir and react for 4 h, then raise the temperature to reflux, and react for 3 h to obtain a reaction solution; among them, the molar ratio of phenylacetonitrile to the alkali in the liquid alkali is 1:1.05.

[0055] S103. Raise the temperature of the reaction solution for concentration until crystals precipitate to obtain a concentrated liquid.

[0056] S104. Cool the concentrated solution for crystallization, separate the crystals after crystallization, and then dry the crystals to obtain anilinium acetate. The purity of sodium anilinacetate is 95.6%, and it contains 3.4% of phenylglycinamide.

[0057] Example 2 S201. Add bottom water accounting for 15% of the volume of phenylglycolonitrile to the chemical feeding tank, put phenylglycolonitrile into the chemical feeding tank, and heat it to 40 - 50 °C to obtain a phenylglycolonitrile suspension.

[0058] S202. Pour the phenylglycolonitrile suspension into a hydrolysis kettle, then add a 50% sodium hydroxide aqueous solution, raise the temperature with stirring, control the reaction temperature at 50 - 60 °C, stir and react for 3 h, then raise the temperature to reflux and react for 2 h to obtain a reaction solution; wherein, the molar ratio of phenylglycolonitrile to the alkali in the liquid alkali is 1∶1.15.

[0059] S203. Raise the temperature of the reaction solution for concentration until crystals precipitate to obtain a concentrated solution.

[0060] S204. Cool the concentrated solution for crystallization, separate the crystals after crystallization, and then dry the crystals to obtain anilinium acetate. The purity of sodium anilinacetate is 95.0%, and it contains 3.5% of phenylglycinamide.

[0061] Example 3 S301. Add bottom water accounting for 10% of the volume of phenylglycolonitrile to the chemical feeding tank, put phenylglycolonitrile into the chemical feeding tank, and heat it to 40 - 50 °C to obtain a phenylglycolonitrile suspension.

[0062] S302. Pour the phenylglycolonitrile suspension into a hydrolysis kettle, then add a 48% sodium hydroxide aqueous solution, raise the temperature with stirring, control the reaction temperature at 50 - 60 °C, stir and react for 3.5 h, then raise the temperature to reflux and react for 2.5 h to obtain a reaction solution; wherein, the molar ratio of phenylglycolonitrile to the alkali in the liquid alkali is 1∶1.1.

[0063] S303. Raise the temperature of the reaction solution for concentration until crystals precipitate to obtain a concentrated solution.

[0064] S304. Cool the concentrated solution for crystallization, separate the crystals after crystallization, and then dry the crystals to obtain anilinium acetate. The purity of sodium anilinacetate is 95.4%, and it contains 3.2% of phenylglycinamide.

[0065] Example 4 S401. The operation is the same as S301.

[0066] S402. Add the aniline acetonitrile suspension into a hydrolysis kettle, add a catalyst accounting for 10% of the weight of the aniline acetonitrile suspension, and then add an aqueous sodium hydroxide solution with a concentration of 48%. Heat up under stirring, control the reaction temperature at 50 - 60 °C, stir and react for 0.5 h, then heat up to reflux and react for 2 h to obtain a reaction solution; wherein, the molar ratio of aniline acetonitrile to the alkali in the liquid alkali is 1∶1.1.

[0067] S403. Operate in the same manner as S303.

[0068] S404. Operate in the same manner as S304. The purity of sodium phenylglycinate is 98.7%, containing less than 0.1% of phenylglycinamide.

[0069] The catalyst is prepared according to the following method: Take 10 parts of iodine and 40 parts of potassium iodide, mix them, add them to 100 parts of water, and stir until the solids are completely dissolved to obtain the catalyst.

[0070] As can be seen from the above embodiments, the purity of the phenylglycine salt (sodium) obtained by the method of the present application is above 95%. The results of Example 4 show that adding a catalyst in the reaction can not only improve the purity of the reaction product phenylglycine salt but also shorten the reaction time, and at the same time reduce the generation of amide by-products in the reaction.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for producing anilinoacetate, characterized in that: The steps include: Add bottom water to the feed tank, put aniline acetonitrile into the feed tank, heat to 40-50°C, and obtain aniline acetonitrile suspension; Add the aniline acetonitrile suspension into the hydrolysis kettle, then add liquid alkali, heat up under stirring, control the reaction temperature to 50-60°C, stir and react for 3-4 hours, then heat up to reflux, react for 2-3 hours to obtain a reaction solution; The reaction solution is heated and concentrated to obtain a concentrated solution; The concentrated solution is cooled and crystallized, and after separation, the crystals are dried to obtain anilinoacetic acid salt.

2. The method for producing anilinoacetate according to claim 1, characterized in that: A catalyst is also added into the hydrolysis kettle; The catalyst is an aqueous solution of potassium iodide of iodine, and the amount of the catalyst added is 5-10% of the weight of the aniline acetonitrile suspension; The catalyst is added into the aniline-acetonitrile suspension before the liquid alkali is added.

3. The method for producing anilinoacetate according to claim 2, characterized in that: The catalyst is configured as follows: By weight, mix 10-12 parts of iodine and 40-50 parts of potassium iodide, add to 100 parts of water and stir until the solid is completely dissolved.

4. The method for producing anilinoacetate according to claim 1, characterized in that: The molar ratio of the aniline acetonitrile to the alkali in the liquid caustic soda is 1: (1.05-1.15).

5. The method for producing anilinoacetate according to claim 1, characterized in that: The liquid alkali is an aqueous solution of sodium hydroxide or potassium hydroxide with a concentration of 45-50%.

6. The method for producing anilinoacetate according to claim 1, characterized in that: The amount of bottom water added is 5-15% of the volume of aniline acetonitrile.

7. A device for producing anilinoacetate, applied to the method for producing anilinoacetate according to any one of claims 1 to 6, characterized in that: It comprises a material tank (1), a hydrolysis kettle (2), a crystallization kettle (3), a dryer (4), a dust collector (41) and an aminoacetate storage tank (42) which are connected in series in sequence; The hydrolysis kettle (2) is also connected to the ammonia collection tank (5) and the condensate storage tank (6) respectively through the condenser (21); The hydrolysis kettle (2) is also connected to the liquid alkali high-level tank (22) and the catalyst metering pump (23) respectively; The crystallization kettle (3) is also connected to the filtrate storage tank (7), and the filtrate storage tank (7) is also connected to the hydrolysis kettle (2).

8. The device for producing anilinoacetate according to claim 7, characterized in that: The ammonia collection tank (5) is also connected to the ammonia drying device (51) and the ammonia absorption device (52) respectively; The ammonia drying device (51) is also connected to the ammonia pipeline (50), and the ammonia absorption device (52) is also respectively connected to the condensate storage tank (6) and the ammonia water storage tank (53).

9. The device for producing anilinoacetate according to claim 7, characterized in that: The crystallization kettle (3) comprises a cylinder (31); The upper end of the cylinder (31) is sealed by an upper seal head (32), and the lower end is sealed by a lower seal head (33); an agitator (34) is provided in the cylinder (31) through the upper seal head (32); A filter screen (35) is provided in the lower sealing head (33); The lower end cap (33) is connected to the filtrate bin (36) via a pipeline with a valve, and the top of the filtrate bin (36) is connected to a vacuum pump (37).

10. The anilinoacetate production device according to claim 9, characterized in that: The stirrer (34) comprises a stirring rod (341) and a stirring scraper (342) arranged vertically, and the stirring rod (341) and the stirring scraper (342) are connected via a connecting plate (343); One side of the stirring scraper (342) is connected to the connecting plate (343), and the other side is disposed in contact with the inner wall of the cylinder (31) and can slide along the inner wall of the cylinder (31).

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