Method for preparing anhydrous acetaldoxime by co-production of diacetylmonoxime and acetaldoxime system

Abstract

The invention relates to a method for preparing anhydrous acetaldoxime by a system for co-producing diacetylmonoxime and acetaldoxime, and relates to the technical field of acetaldoxime. The method comprises the following steps: adding diacetylmonoxime, acetaldehyde and a modified TS-1 molecular sieve into a reactor, and reacting to generate crude acetaldehyde oxime; feeding the crude acetaldehyde oxime into an acetaldehyde removal tower for rectification separation; rectifying and separating acetaldehyde tower bottoms to obtain butanone; adding an extracting agent into the tower top acetaldoxime solution, and feeding into a distillation kettle for extraction; the extracted acetaldehyde oxime is fed into an acetaldehyde oxime finished product tower to be further rectified and purified; the preparation method comprises the following steps: reacting a TS-1 molecular sieve, anhydrous toluene and 3-mercaptopropyltrimethoxysilane to obtain a sulfhydrylated TS-1 molecular sieve; the preparation method comprises the following steps: taking a sulfhydrylated TS-1 molecular sieve, tetrahydrofuran, diethyl vinylphosphonate, mercaptododeborane disodium salt and Darocur1173 as photoinitiators, and reacting under the irradiation of 365nm ultraviolet light to obtain the modified TS-1 molecular sieve. The acetaldehyde oxime prepared by the method has higher content and yield.

Description

Technical Field

[0001] The invention relates to the technical field of acetaldehyde oxime, in particular to a method for preparing anhydrous acetaldehyde oxime by co-producing butanone oxime and acetaldehyde oxime. Background Art

[0002] Acetaldehyde oxime is the primary raw material for the production of the pesticide methomyl and an intermediate for methylthioacetaldehyde oxime. Its quality directly impacts the quality and yield of both methomyl and methylthioacetaldehyde oxime. Currently, the acetaldehyde oxime available on the domestic market is a 40% aqueous solution, which is high in impurities and unstable in quality. Export of methylthioacetaldehyde oxime and joint ventures producing methomyl require acetaldehyde oxime of higher purity. Furthermore, acetaldehyde oxime used in certain organic synthesis reactions must be anhydrous.

[0003] Chinese patent CN101624353B: A method for preparing anhydrous acetaldehyde oxime by co-producing butanone oxime and acetaldehyde oxime, comprising the following steps: adding a hydroxylamine solution, acetaldehyde, and a base to an oximation reactor with a stirring or external circulation system for reaction to produce an acetaldehyde oxime liquid; passing the acetaldehyde oxime liquid obtained above through a cooler and then sent to a liquid-liquid separator, the upper oil phase being sent to a distillation tower A for rectification to obtain an acetaldehyde oxime aqueous solution with a mass percentage of about 50% and anhydrous acetaldehyde oxime, the lower phase being a solution containing inorganic salts being sent to a distillation tower B for rectification, and an acetaldehyde oxime aqueous solution with a mass percentage of about 50% being obtained at the top of the tower, and the bottom of the tower being an inorganic salt aqueous solution without acetaldehyde oxime.

[0004] Chinese patent CN116217430B discloses a method for separating and purifying high-concentration anhydrous acetaldehyde oxime, comprising: preparing an acetaldehyde oxime reaction solution through an ammoximation reaction; subjecting the acetaldehyde oxime reaction solution to distillation to remove the reaction solvent used in the ammoximation reaction to obtain a distilled bottom reaction solution; and then sequentially performing the following steps: purifying an inorganic salt to obtain a salting-out agent; adding the salting-out agent to the distilled bottom reaction solution, heating and stirring, and then standing to allow the reaction solution to separate into layers; and taking the resulting upper layer of the reaction solution, subjecting it to a primary distillation to separate water, and then subjecting it to a secondary distillation to obtain the acetaldehyde oxime as a product.

[0005] Chinese patent CN110746316B discloses a method for separating and purifying acetaldehyde oxime, relating to the technical field of oxime separation and purification. The method comprises the following steps: 1) neutralizing the acetaldehyde oxime reaction solution prepared by an oxime exchange reaction between cyclohexanone oxime and acetaldehyde with a base, and controlling the pH of the acetaldehyde oxime reaction solution to 7 after neutralization; 2) adding toluene to the acetaldehyde oxime reaction solution and subjecting it to vacuum distillation to separate acetaldehyde oxime and cyclohexanone, respectively, to obtain an acetaldehyde oxime-toluene mixed solution and cyclohexanone; 3) adding the obtained acetaldehyde oxime-toluene mixed solution to an extractant, water, and separating toluene and acetaldehyde oxime using a continuous extraction process to obtain an acetaldehyde oxime aqueous solution and toluene, respectively; and 4) subjecting the acetaldehyde oxime aqueous solution to vacuum distillation to obtain the acetaldehyde oxime product.

[0006] The acetaldehyde oxime prepared by the above patents and prior art has a complex process, and the acetaldehyde oxime content and yield need to be further improved. Summary of the Invention

[0007] In order to solve the above problems, the present invention provides a method for preparing anhydrous acetaldehyde oxime by co-producing butanone oxime and acetaldehyde oxime, which is characterized by comprising the following steps:

[0008] Step 1 reaction system:

[0009] According to the weight ratio, 36-48 parts of butanone oxime prepared by the butanone oxime production process and 72-86 parts of acetaldehyde are measured and mixed into a reactor. After the materials are mixed, the temperature is raised to 60-70°C, and a crude acetaldehyde oxime product is generated by reaction under normal pressure and the action of a catalyst. The crude product overflows into a crude acetaldehyde oxime tank. The catalyst is a modified TS-1 molecular sieve, and the addition amount is 0.5-2% of the total weight of the materials. The materials are heated by hot water heating in a jacket, the hot water inlet temperature is 80-90°C, and the hot water flow rate is 1-3m 3 / h, reaction time is 2-3h;

[0010] Step 2: Acetaldehyde removal process:

[0011] The material in the crude acetaldehyde oxime tank is pumped to the acetaldehyde removal tower through the acetaldehyde tower feed pump and distilled under normal pressure. The tower bottom temperature is controlled at 90-100℃ and the tower top liquid is 70-80℃. The material is condensed in two stages and then enters the distillate tank. The distillate is divided into two paths, one as reflux liquid and the other to return to the reactor. The steam pressure is 0.3-0.4MPa and the steam flow rate is 0.5-2m 3 / h, the reflux ratio is controlled at 1.7-2:1;

[0012] Step 3: butanone removal process:

[0013] The acetaldehyde tower bottom liquid is pumped to the butanone removal tower, where it is distilled and separated at an absolute pressure of 50-60KPa, the tower bottom temperature is controlled at 85-95℃, and the tower top is 50-60℃. The top material is condensed in two stages and then goes to the butanone tank; the tower bottom reboiler has a steam pressure of 0.2-0.3MPa and a steam flow rate of 1.5-2m 3 / h; the inlet temperature of cooling water of the top condenser is 20-25℃;

[0014] Step 4 Extraction process:

[0015] S1: Add acetaldehyde oxime solution to distillation kettle A, add extractant to distillation kettle B, and then heat distillation kettles A and B to boiling using an electric heating rod;

[0016] S2: The vaporized acetaldehyde oxime-water vapor and the extractant gas enter the gas mixer together. After mixed extraction, they enter the condenser for condensation. The cooling water inlet temperature is 20-25°C. After condensation, they enter the oil-water separator. The water phase is returned to the distillation kettle A through a circulation pump, and the oil phase is returned to the distillation kettle B through a circulation pump.

[0017] S3: Repeat steps S1 and S2 continuously until the top temperature of the still A reaches 100°C, stop heating, and cool to room temperature;

[0018] Step 5: Finished product distillation process:

[0019] The liquid in the distillation kettle B is pumped to the acetaldehyde oxime finished product tower 1 after being pressurized by the pump, and is distilled and separated at an absolute pressure of 20-30KPa, a kettle temperature of 75-85℃, and a tower top temperature of 50-60℃. The top liquid is condensed and enters the distillate tank of the finished product tower 1, one way is used as reflux, and the other way is used to go to the acetaldehyde finished product tank; the steam pressure of the kettle reboiler is 0.1-0.2MPa, and the steam flow rate is 1-2m 3 / h; the reflux ratio is controlled at 1.3-1.7:1.

[0020] The mass concentration of the acetaldehyde oxime solution in S1 is 38-42%.

[0021] The extractant of S1 is dichloromethane.

[0022] The distillation kettle A of S1 is heated to 100-110°C.

[0023] The distillation kettle B of S1 is heated to 30-35°C.

[0024] The preparation method of the modified TS-1 molecular sieve is as follows:

[0025] K1: Weigh 100-120 parts of TS-1 molecular sieve, disperse it in 1000-1400 parts of anhydrous toluene, and ultrasonicate it for 30 minutes to make it uniformly dispersed; add 4-8 parts of 3-mercaptopropyltrimethoxysilane KH-590 to the above dispersion, and reflux it at 50-60°C under a nitrogen atmosphere for 18-24 hours; after the reaction is completed, filter it, and then vacuum dry it at 80-100°C for 12-15 hours to obtain the thiolated TS-1 molecular sieve;

[0026] K2: Add 100-120 parts of thiolated TS-1 molecular sieve to 1000-1500 parts of tetrahydrofuran and disperse uniformly by ultrasonication. Then, add 1-3 parts of diethyl vinylphosphonate, 0.2-0.5 parts of disodium mercaptododecaborane CAS: 12294-22-3, and 0.05-0.1 parts of Darocur 1173 as a photoinitiator. Under 365nm ultraviolet light, stir and react at room temperature for 30-50 minutes. After the reaction is completed, filter and vacuum dry at 60-80°C for 10-12 hours to obtain the modified TS-1 molecular sieve.

[0027] Reaction mechanism

[0028] A thiol-olefin click chemistry reaction between the thiolated TS-1 molecular sieve and diethyl vinylphosphonate and disodium mercaptododecaborane produces a modified TS-1 molecular sieve. Butanone oxime and acetaldehyde molecules are adsorbed onto the surface active sites of the modified TS-1 molecular sieve through physical and chemical adsorption. The phosphonic acid groups and crown ether functional groups introduced by diethyl vinylphosphonate can selectively complex certain metal ions or reactant molecules, altering the reaction microenvironment and reaction pathway. The crown ether complexes alkali metal ions that may be present in the reaction, adjusting the reaction pH and ionic strength, thereby improving the selectivity for acetaldehyde oxime.

[0029] Butanone oxime and acetaldehyde molecules adsorbed on the catalyst surface react at the active sites. The phosphonic acid group acts as an acid center, promoting proton transfer in the reaction and accelerating the oximation reaction to produce acetaldehyde oxime and butanone.

[0030] Technical Effects

[0031] The method of preparing anhydrous acetaldehyde oxime by co-producing butanone oxime and acetaldehyde oxime in the present invention has the following significant effects compared with the prior art:

[0032] 1. The present invention uses dichloromethane as an extractant and adopts a gas phase extraction method to prepare anhydrous acetaldehyde oxime from an acetaldehyde oxime solution; the process of the present invention is simple, and the prepared acetaldehyde oxime has good storage stability.

[0033] 2. The present invention adopts the method of first fractionating the extractant under normal pressure and then preparing anhydrous acetaldehyde oxime by vacuum distillation. The prepared acetaldehyde oxime has high content and high yield.

[0034] 3. Improve catalytic activity

[0035] The introduction of diethyl vinylphosphonate increases the number and types of active sites on the catalyst surface. The phosphonic acid groups can act as acid centers or Lewis acid centers, effectively activating reactant molecules and reducing the activation energy of the reaction, thereby increasing the reaction rate and catalytic activity.

[0036] These functional groups improve the electronic properties and chemical environment of the catalyst surface, making it easier for reactants to adsorb and react on the catalyst surface, thereby improving the catalytic efficiency.

[0037] 4. Enhance selectivity

[0038] Specific functional group structures can selectively regulate the adsorption and reaction of reactants and products; for example, the interaction between the phosphonic acid group and the reactant molecules has a certain degree of selectivity, which can promote the specific reaction path between butanone oxime and acetaldehyde, reduce the occurrence of side reactions, and thus improve the selectivity of acetaldehyde oxime.

[0039] The steric hindrance effect of functional groups can also affect the selectivity of the reaction, preventing some undesirable side reactions from occurring and making the reaction more inclined to produce the target product acetaldehyde oxime. DETAILED DESCRIPTION

[0040] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description in conjunction with the embodiments and comparative examples:

[0041] Acetaldehyde oxime was detected by gas chromatography.

[0042] Example 1

[0043] A method for preparing anhydrous acetaldehyde oxime by co-producing butanone oxime and acetaldehyde oxime, characterized by comprising the following steps:

[0044] Step 1 reaction system:

[0045] 36 kg of butanone oxime prepared in the butanone oxime production process and 72 kg of acetaldehyde are mixed after metering and introduced into a reactor. After mixing, the materials are heated to 60°C and reacted under normal pressure and the action of a catalyst to produce a crude acetaldehyde oxime product, which overflows into a crude acetaldehyde oxime tank. The catalyst is a modified TS-1 molecular sieve, and the addition amount is 0.5% of the total mass of the materials. The materials are heated by hot water heating in a jacket, with the hot water inlet temperature being 80°C and the hot water flow rate being 1 m 3 / h, reaction time is 2h;

[0046] Step 2: Acetaldehyde removal process:

[0047] The material in the crude acetaldehyde oxime tank is pumped to the acetaldehyde removal tower through the acetaldehyde tower feed pump and distilled under normal pressure. The tower bottom temperature is controlled at 90℃ and the tower top liquid is 70℃. The material is condensed in two stages and then enters the distillate tank. The distillate is divided into two paths, one as reflux liquid and the other to return to the reactor. The steam pressure is 0.3MPa and the steam flow rate is 0.5m 3 / h, and the reflux ratio is controlled at 1.7:1;

[0048] Step 3: butanone removal process:

[0049] The acetaldehyde tower bottom liquid is pumped to the butanone removal tower, where it is distilled and separated at an absolute pressure of 50KPa, the tower bottom temperature is controlled at 85℃, and the tower top liquid is 50℃. The tower top material is condensed in two stages and then goes to the butanone tank; the tower bottom reboiler has a steam pressure of 0.2MPa and a steam flow rate of 1m 3 / h; the inlet temperature of cooling water of the top condenser is 20℃;

[0050] Step 4 Extraction process:

[0051] S1: Add acetaldehyde oxime solution to distillation kettle A, add extractant to distillation kettle B, and then heat distillation kettles A and B to boiling using an electric heating rod;

[0052] S2: The vaporized acetaldehyde oxime-water vapor and the extractant gas enter the gas mixer together. After mixed extraction, they enter the condenser for condensation. The cooling water inlet temperature is 20°C. After condensation, they enter the oil-water separator. The water phase is returned to the distillation kettle A through a circulation pump, and the oil phase is returned to the distillation kettle B through a circulation pump.

[0053] S3: Repeat steps S1 and S2 continuously until the top temperature of the still A reaches 100°C, stop heating, and cool to room temperature;

[0054] Step 5: Finished product distillation process:

[0055] The liquid in the distillation kettle B is pumped to the acetaldehyde oxime finished product tower 1 after being pressurized by the pump, and is distilled and separated at an absolute pressure of 20KPa, a kettle temperature of 75℃, and a tower top temperature of 50℃. The top liquid is condensed and enters the distillate tank of the finished product tower 1, one way is used as reflux, and the other way is used to go to the acetaldehyde finished product tank; the steam pressure of the kettle reboiler is 0.1MPa, and the steam flow rate is 1m 3 / h; the reflux ratio is controlled at 1.3:1.

[0056] The mass concentration of the acetaldehyde oxime solution in S1 is 38%.

[0057] The extractant of S1 is dichloromethane.

[0058] The distillation kettle A of S1 is heated to 100°C.

[0059] The distillation kettle B of S1 was heated to 30°C.

[0060] The preparation method of the modified TS-1 molecular sieve is as follows:

[0061] K1: Weigh 100 kg of TS-1 molecular sieve, disperse it in 1000 kg of anhydrous toluene, and ultrasonicate it for 30 minutes to make it uniformly dispersed; add 4 kg of 3-mercaptopropyltrimethoxysilane KH-590 to the above dispersion, and reflux it at 50°C under a nitrogen atmosphere for 18 hours; after the reaction is completed, filter it, and then vacuum dry it at 80°C for 12 hours to obtain the thiolated TS-1 molecular sieve;

[0062] K2: Add 100 kg of thiolated TS-1 molecular sieve to 1000 kg of tetrahydrofuran and disperse it evenly by ultrasonication. Then, add 1 kg of diethyl vinylphosphonate, 0.2 kg of disodium mercaptododecaborane CAS: 12294-22-3, and 0.05 kg of Darocur 1173 as a photoinitiator. Under 365 nm ultraviolet light, stir and react at room temperature for 30 minutes. After the reaction is completed, filter and vacuum dry at 60°C for 10 hours to obtain the modified TS-1 molecular sieve.

[0063] Example 2

[0064] A method for preparing anhydrous acetaldehyde oxime by co-producing butanone oxime and acetaldehyde oxime, characterized by comprising the following steps:

[0065] Step 1 reaction system:

[0066] 40 kg of butanone oxime prepared in the butanone oxime production process and 78 kg of acetaldehyde are mixed after metering and introduced into a reactor. After mixing, the materials are heated to 65°C and reacted under normal pressure and the action of a catalyst to produce a crude acetaldehyde oxime product, which overflows into a crude acetaldehyde oxime tank. The catalyst is a modified TS-1 molecular sieve, and the addition amount is 1% of the total mass of the materials. The materials are heated by hot water heating in a jacket, with the hot water inlet temperature being 85°C and the hot water flow rate being 2 m 3 / h, reaction time is 2.5h;

[0067] Step 2: Acetaldehyde removal process:

[0068] The material in the crude acetaldehyde oxime tank is pumped to the acetaldehyde removal tower through the acetaldehyde tower feed pump and distilled under normal pressure. The tower bottom temperature is controlled at 95℃ and the tower top liquid is 75℃. The material is condensed in two stages and then enters the distillate tank. The distillate is divided into two paths, one as reflux liquid and the other as return to the reactor. The steam pressure is 0.35MPa and the steam flow rate is 1m 3 / h, and the reflux ratio is controlled at 1.8:1;

[0069] Step 3: butanone removal process:

[0070] The acetaldehyde tower bottom liquid is pumped to the butanone removal tower, where it is distilled and separated at an absolute pressure of 55KPa, the tower bottom temperature is controlled at 90℃, and the tower top liquid is 55℃. The tower top material is condensed in two stages and then goes to the butanone tank; the tower bottom reboiler has a steam pressure of 0.25MPa and a steam flow rate of 1.6m 3 / h; the inlet temperature of cooling water of the top condenser is 22℃;

[0071] Step 4 Extraction process:

[0072] S1: Add acetaldehyde oxime solution to distillation kettle A, add extractant to distillation kettle B, and then heat distillation kettles A and B to boiling using an electric heating rod;

[0073] S2: The vaporized acetaldehyde oxime-water vapor and the extractant gas enter the gas mixer together. After mixed extraction, they enter the condenser for condensation. The cooling water inlet temperature is 22°C. After condensation, they enter the oil-water separator. The water phase is returned to the distillation kettle A through a circulation pump, and the oil phase is returned to the distillation kettle B through a circulation pump.

[0074] S3: Repeat steps S1 and S2 continuously until the top temperature of the still A reaches 100°C, stop heating, and cool to room temperature;

[0075] Step 5: Finished product distillation process:

[0076] The liquid in the distillation kettle B is pumped to the acetaldehyde oxime finished product tower 1 after being pressurized by the pump, and is distilled and separated at an absolute pressure of 25KPa, a kettle temperature of 80℃, and a tower top temperature of 55℃. The top liquid is condensed and enters the distillate tank of the finished product tower 1, one way as reflux and the other way to the acetaldehyde finished product tank; the steam pressure of the kettle reboiler is 0.15MPa, and the steam flow rate is 1.5m 3 / h; the reflux ratio is controlled at 1.4:1.

[0077] The mass concentration of the acetaldehyde oxime solution in S1 is 40%.

[0078] The extractant of S1 is dichloromethane.

[0079] The distillation kettle A of S1 was heated to 105°C.

[0080] The distillation kettle B of S1 was heated to 30°C.

[0081] The preparation method of the modified TS-1 molecular sieve is as follows:

[0082] K1: Weigh 105 kg of TS-1 molecular sieve and disperse it in 1100 kg of anhydrous toluene. Ultrasonicate for 30 minutes to achieve uniform dispersion. Add 5 kg of 3-mercaptopropyltrimethoxysilane KH-590 to the dispersion and reflux at 55°C under a nitrogen atmosphere for 20 hours. After the reaction is complete, filter and vacuum dry at 85°C for 13 hours to obtain the thiolated TS-1 molecular sieve.

[0083] K2: Add 105 kg of thiolated TS-1 molecular sieve to 1100 kg of tetrahydrofuran and disperse it evenly by ultrasonication. Then, add 2 kg of diethyl vinylphosphonate, 0.3 kg of disodium mercaptododecaborane CAS: 12294-22-3, and 0.06 kg of Darocur 1173 as a photoinitiator. Under 365 nm ultraviolet light, stir and react at room temperature for 35 minutes. After the reaction is completed, filter and vacuum dry at 65°C for 11 hours to obtain the modified TS-1 molecular sieve.

[0084] Example 3

[0085] A method for preparing anhydrous acetaldehyde oxime by co-producing butanone oxime and acetaldehyde oxime, characterized by comprising the following steps:

[0086] Step 1 reaction system:

[0087] 44 kg of butanone oxime prepared in the butanone oxime production process and 83 kg of acetaldehyde are mixed after metering and introduced into a reactor. After mixing, the materials are heated to 65°C and reacted under normal pressure and the action of a catalyst to produce a crude acetaldehyde oxime product, which overflows into a crude acetaldehyde oxime tank. The catalyst is a modified TS-1 molecular sieve, and the addition amount is 1.5% of the total mass of the materials. The materials are heated by hot water heating in the jacket. The hot water inlet temperature is 85°C and the hot water flow rate is 2.5m 3 / h, reaction time is 2.5h;

[0088] Step 2: Acetaldehyde removal process:

[0089] The material in the crude acetaldehyde oxime tank is pumped to the acetaldehyde removal tower through the acetaldehyde tower feed pump and distilled under normal pressure. The tower bottom temperature is controlled at 95℃ and the tower top liquid is 75℃. The material is condensed in two stages and then enters the distillate tank. The distillate is divided into two paths, one as reflux liquid and the other to return to the reactor. The steam pressure is 0.35MPa and the steam flow rate is 1.5m 3 / h, and the reflux ratio is controlled at 1.9:1;

[0090] Step 3: butanone removal process:

[0091] The acetaldehyde tower bottom liquid is pumped to the butanone removal tower, where it is distilled and separated at an absolute pressure of 55KPa, the tower bottom temperature is controlled at 90℃, and the tower top liquid is 55℃. The tower top material is condensed in two stages and then goes to the butanone tank; the tower bottom reboiler has a steam pressure of 0.25MPa and a steam flow rate of 1.9m 3 / h; the inlet temperature of cooling water of the top condenser is 24℃;

[0092] Step 4 Extraction process:

[0093] S1: Add acetaldehyde oxime solution to distillation kettle A, add extractant to distillation kettle B, and then heat distillation kettles A and B to boiling using an electric heating rod;

[0094] S2: The vaporized acetaldehyde oxime-water vapor and the extractant gas enter the gas mixer together. After mixed extraction, they enter the condenser for condensation. The cooling water inlet temperature is 24°C. After condensation, they enter the oil-water separator. The water phase is returned to the distillation kettle A through a circulation pump, and the oil phase is returned to the distillation kettle B through a circulation pump.

[0095] S3: Repeat steps S1 and S2 continuously until the top temperature of the still A reaches 100°C, stop heating, and cool to room temperature;

[0096] Step 5: Finished product distillation process:

[0097] The liquid in the distillation kettle B is pumped to the acetaldehyde oxime finished product tower 1 after being pressurized by the pump, and is distilled and separated at an absolute pressure of 25KPa, a kettle temperature of 80℃, and a tower top temperature of 55℃. The top liquid is condensed and enters the distillate tank of the finished product tower 1, one way as reflux and the other way to the acetaldehyde finished product tank; the steam pressure of the kettle reboiler is 0.15MPa, and the steam flow rate is 1.5m 3 / h; the reflux ratio is controlled at 1.6:1.

[0098] The mass concentration of the acetaldehyde oxime solution in S1 is 40%.

[0099] The extractant of S1 is dichloromethane.

[0100] The distillation kettle A of S1 was heated to 105°C.

[0101] The distillation kettle B of S1 was heated to 35°C.

[0102] The preparation method of the modified TS-1 molecular sieve is as follows:

[0103] K1: Weigh 115 kg of TS-1 molecular sieve and disperse it in 1300 kg of anhydrous toluene. Ultrasonicate for 30 minutes to achieve uniform dispersion. Add 7 kg of 3-mercaptopropyltrimethoxysilane KH-590 to the dispersion and reflux at 55°C under a nitrogen atmosphere for 22 hours. After the reaction is complete, filter and vacuum dry at 95°C for 14 hours to obtain the thiolated TS-1 molecular sieve.

[0104] K2: Add 115 kg of thiolated TS-1 molecular sieve to 1400 kg of tetrahydrofuran and disperse it evenly by ultrasonication. Then, add 2 kg of diethyl vinylphosphonate, 0.4 kg of disodium mercaptododecaborane CAS: 12294-22-3, and 0.08 kg of Darocur 1173 as a photoinitiator. Under 365 nm ultraviolet light, stir and react at room temperature for 45 minutes. After the reaction is completed, filter and vacuum dry at 75°C for 11 hours to obtain the modified TS-1 molecular sieve.

[0105] Example 4

[0106] A method for preparing anhydrous acetaldehyde oxime by co-producing butanone oxime and acetaldehyde oxime, characterized by comprising the following steps:

[0107] Step 1 reaction system:

[0108] 48 kg of butanone oxime prepared in the butanone oxime production process and 86 kg of acetaldehyde are mixed after metering and introduced into a reactor. After mixing, the materials are heated to 70°C and reacted under normal pressure and the action of a catalyst to produce a crude acetaldehyde oxime product, which overflows into a crude acetaldehyde oxime tank. The catalyst is a modified TS-1 molecular sieve, and the addition amount is 2% of the total mass of the materials. The materials are heated by hot water heating in the jacket. The hot water inlet temperature is 90°C and the hot water flow rate is 3m 3 / h, reaction time is 3h;

[0109] Step 2: Acetaldehyde removal process:

[0110] The material in the crude acetaldehyde oxime tank is pumped to the acetaldehyde removal tower through the acetaldehyde tower feed pump and distilled under normal pressure. The temperature of the tower bottom is controlled at 100℃ and the top liquid is 80℃. The material is condensed in two stages and then enters the distillate tank. The distillate is divided into two paths, one as reflux liquid and the other as return to the reactor. The steam pressure is 0.4MPa and the steam flow rate is 2m 3 / h, the reflux ratio is controlled at 2:1;

[0111] Step 3: butanone removal process:

[0112] The acetaldehyde tower bottom liquid is pumped to the butanone removal tower, where it is distilled and separated at an absolute pressure of 60KPa, the tower bottom temperature is controlled at 95℃, and the tower top liquid is 60℃. The tower top material is condensed in two stages and then goes to the butanone tank; the tower bottom reboiler has a steam pressure of 0.3MPa and a steam flow rate of 2m 3 / h; the inlet temperature of cooling water of the top condenser is 25℃;

[0113] Step 4 Extraction process:

[0114] S1: Add acetaldehyde oxime solution to distillation kettle A, add extractant to distillation kettle B, and then heat distillation kettles A and B to boiling using an electric heating rod;

[0115] S2: The vaporized acetaldehyde oxime-water vapor and the extractant gas enter the gas mixer together. After mixed extraction, they enter the condenser for condensation. The cooling water inlet temperature is 25°C. After condensation, they enter the oil-water separator. The water phase is returned to the distillation kettle A through a circulation pump, and the oil phase is returned to the distillation kettle B through a circulation pump.

[0116] S3: Repeat steps S1 and S2 continuously until the top temperature of the still A reaches 100°C, stop heating, and cool to room temperature;

[0117] Step 5: Finished product distillation process:

[0118] The liquid in the distillation kettle B is pumped to the acetaldehyde oxime finished product tower 1, and is distilled and separated at an absolute pressure of 30KPa, a kettle temperature of 85℃, and a tower top temperature of 60℃. The top liquid is condensed and enters the distillate tank of the finished product tower 1, one way is used as reflux, and the other way is used to go to the acetaldehyde finished product tank; the steam pressure of the kettle reboiler is 0.2MPa, and the steam flow rate is 2m 3 / h; the reflux ratio is controlled at 1.7:1.

[0119] The mass concentration of the acetaldehyde oxime solution in S1 is 42%.

[0120] The extractant of S1 is dichloromethane.

[0121] The distillation kettle A of S1 was heated to 105°C.

[0122] The distillation kettle B of S1 was heated to 35°C.

[0123] The preparation method of the modified TS-1 molecular sieve is as follows:

[0124] K1: Weigh 120 kg of TS-1 molecular sieve, disperse it in 1400 kg of anhydrous toluene, and ultrasonicate it for 30 minutes to make it uniformly dispersed; add 8 kg of 3-mercaptopropyltrimethoxysilane KH-590 to the above dispersion, and reflux it at 60°C under a nitrogen atmosphere for 24 hours; after the reaction is completed, filter it, and then vacuum dry it at 100°C for 15 hours to obtain the thiolated TS-1 molecular sieve;

[0125] K2: Add 120 kg of thiolated TS-1 molecular sieve to 1500 kg of tetrahydrofuran and disperse it evenly by ultrasonication. Then add 3 kg of diethyl vinylphosphonate, 0.5 kg of disodium mercaptododecaborane (CAS: 12294-22-3), and 0.1 kg of Darocur 1173 as a photoinitiator. Under 365 nm ultraviolet light, stir and react at room temperature for 50 minutes. After the reaction is completed, filter and vacuum dry at 80°C for 12 hours to obtain the modified TS-1 molecular sieve.

[0126] Comparative Example 1

[0127] The TS-1 molecular sieve was not modified, and the other steps were the same as in Example 1.

[0128] Comparative Example 2

[0129] Except that diethyl vinylphosphonate was not added, the other steps were the same as those in Example 1.

[0130] Comparative Example 3

[0131] The other steps were the same as in Example 1 except that disodium mercaptododecaborane was not added.

[0132] Acetaldehyde oxime content / % Acetaldehyde oxime yield / % Example 1 99.59 94.95 Example 2 99.63 95.18 Example 3 99.70 95.41 Example 4 99.75 95.62 Comparative Example 1 88.54 82.87 Comparative Example 2 95.32 89.25 Comparative Example 3 96.11 90.80

[0133] Through the data analysis of the above examples and comparative examples, the acetaldehyde oxime prepared by the present invention has a higher content and yield.

[0134] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications to equivalent embodiments using the technical contents disclosed above. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for preparing anhydrous acetaldehyde oxime by co-producing butanone oxime and acetaldehyde oxime, characterized in that: The following steps are involved: Step 1 reaction system: According to the weight ratio, 36-48 parts of butanone oxime prepared by the butanone oxime production process and 72-86 parts of acetaldehyde are measured and mixed into a reactor. After the materials are mixed, the temperature is raised to 60-70°C, and a crude acetaldehyde oxime product is generated by reaction under normal pressure and the action of a catalyst. The crude product overflows into a crude acetaldehyde oxime tank. The catalyst is a modified TS-1 molecular sieve, and the addition amount is 0.5-2% of the total weight of the materials. The materials are heated by hot water heating in a jacket, the hot water inlet temperature is 80-90°C, and the hot water flow rate is 1-3m 3 / h, reaction time is 2-3h; Step 2: Acetaldehyde removal process: The material in the crude acetaldehyde oxime tank is pumped to the acetaldehyde removal tower via the acetaldehyde tower feed pump for distillation separation under normal pressure. The tower bottom temperature is controlled at 90-100°C, and the tower top liquid is 70-80°C. The material is condensed in two stages and then enters the distillate tank. The distillate is divided into two paths: one as reflux liquid and the other to return to the reactor. The steam pressure is 0.3-0.4MPa and the steam flow rate is 0.5-2m 3 / h, the reflux ratio is controlled at 1.7-2:1; Step 3: butanone removal process: The acetaldehyde tower bottom liquid is pumped to the butanone removal tower, where it is distilled and separated at an absolute pressure of 50-60KPa, the tower bottom temperature is controlled at 85-95℃, and the tower top liquid is 50-60℃. The tower top material is condensed in two stages and then goes to the butanone tank; the tower bottom reboiler has a steam pressure of 0.2-0.3MPa and a steam flow rate of 1.5-2m 3 / h,; the inlet temperature of cooling water of the top condenser is 20-25℃; Step 4 Extraction process: S1: Add acetaldehyde oxime solution to distillation kettle A, add extractant to distillation kettle B, and then heat distillation kettles A and B to boiling using an electric heating rod; S2: The vaporized acetaldehyde oxime-water vapor and the extractant gas enter the gas mixer together. After mixed extraction, they enter the condenser for condensation. The cooling water inlet temperature is 20-25°C. After condensation, they enter the oil-water separator. The water phase is returned to the distillation kettle A through a circulation pump, and the oil phase is returned to the distillation kettle B through a circulation pump. S3: Repeat steps S1 and S2 continuously until the top temperature of the still A reaches 100°C, stop heating, and cool to room temperature; Step 5: Finished product distillation process: The liquid in the distillation kettle B is pumped to the acetaldehyde oxime finished product tower 1 after being pressurized by the pump, and is distilled and separated at an absolute pressure of 20-30KPa, a kettle temperature of 75-85℃, and a tower top temperature of 50-60℃. The top liquid is condensed and enters the distillate tank of the finished product tower 1, one way is used as reflux, and the other way is used to go to the acetaldehyde finished product tank; the steam pressure of the kettle reboiler is 0.1-0.2MPa, and the steam flow rate is 1-2m 3 / h,; the reflux ratio is controlled at 1.3-1.7:1; The modified TS-1 molecular sieve is obtained by reacting mercaptolated TS-1 molecular sieve with diethyl vinylphosphonate and disodium mercaptododecaborane.

2. The method for preparing anhydrous acetaldehyde oxime by co-producing butanone oxime and acetaldehyde oxime according to claim 1, characterized in that: The mass concentration of the acetaldehyde oxime solution in S1 is 38-42%.

3. The method for preparing anhydrous acetaldehyde oxime by co-producing butanone oxime and acetaldehyde oxime according to claim 1, characterized in that: The extractant of S1 is dichloromethane.

4. The method for preparing anhydrous acetaldehyde oxime by co-producing butanone oxime and acetaldehyde oxime according to claim 1, characterized in that: The distillation kettle A of S1 is heated to 100-110°C.

5. The method for preparing anhydrous acetaldehyde oxime by co-producing butanone oxime and acetaldehyde oxime according to claim 1, characterized in that: The distillation kettle B of S1 is heated to 30-35°C.

6. The method for preparing anhydrous acetaldehyde oxime by co-producing butanone oxime and acetaldehyde oxime according to claim 1, characterized in that: The preparation method of the modified TS-1 molecular sieve is as follows: K1: Weigh 100-120 parts of TS-1 molecular sieve, disperse it in 1000-1400 parts of anhydrous toluene, and ultrasonicate it for 30 minutes to make it uniformly dispersed; add 4-8 parts of 3-mercaptopropyltrimethoxysilane to the above dispersion, and reflux it at 50-60°C under a nitrogen atmosphere for 18-24 hours; after the reaction is completed, filter it, and then vacuum dry it at 80-100°C for 12-15 hours to obtain the thiolated TS-1 molecular sieve; K2: Add 100-120 parts of thiolated TS-1 molecular sieve to 1000-1500 parts of tetrahydrofuran and disperse uniformly by ultrasonication. Then, add 1-3 parts of diethyl vinylphosphonate, 0.2-0.5 parts of disodium mercaptododecaborane, and 0.05-0.1 parts of Darocur 1173 as a photoinitiator. Under 365nm ultraviolet light, stir and react at room temperature for 30-50 minutes. After the reaction is completed, filter and vacuum dry at 60-80°C for 10-12 hours to obtain the modified TS-1 molecular sieve.