Efficient diethyl ether purification process

Abstract

The invention discloses an efficient diethyl ether purification process, and belongs to the technical field of diethyl ether purification processes. Comprising the following steps: dynamically adsorbing diethyl ether through an adsorption column filled with a composite filler; adding a complexing agent into the effluent, stirring and reacting to obtain a mixed solution; performing normal-pressure separation on the mixed solution through a divided-wall rectifying tower, then performing reduced-pressure separation, collecting fractions, filtering the fractions through a polytetrafluoroethylene membrane, and packaging the fractions to obtain the high-purity diethyl ether. The composite filler is prepared from thiourea modified D101 macroporous resin and 4A molecular sieve powder through alumina sol treatment, silane coupling agent modification and programmed heating firing. The complexing agent is prepared by carrying out reaction on SAA-15 mesoporous molecular sieve loaded phosphotungstic acid and an 18-crown-6 ether derivative. According to the process, peroxide, trace moisture, alcohol and organic impurities in diethyl ether are remarkably removed, efficient separation and purification are achieved, an ultra-high-purity diethyl ether product is obtained, meanwhile, the process is stable and efficient, and the process is suitable for preparing high-purity diethyl ether.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ether purification process, and particularly relates to an efficient ether purification process. BACKGROUND

[0002] As an important organic solvent and chemical raw material, ether is widely used in the fields of medicine synthesis, pesticide preparation, polymer material polymerization and analytical detection. However, the commercially available ether usually contains trace amounts of water, peroxide, alcohol and organic impurities. The existence of these impurities not only reduces the chemical stability of ether, but also may cause the generation of peroxide with explosion risk during storage, which seriously affects the application safety and reaction efficiency of ether. Especially in the fields of pharmaceutical and precise chemical synthesis, the insufficient purity of ether will directly affect the yield and quality of products, and even interfere with the catalytic reaction

[0003] The ether purification process commonly used in industry at present mainly includes steps of adsorption impurity removal, drying and dehydration and rectification separation. Among them, a single adsorbent such as activated alumina or molecular sieve is usually used in the adsorption link to remove peroxide, but the adsorption selectivity of such materials for trace amounts of organic impurities such as alcohol and aldehyde is poor, and the adsorption efficiency is easily reduced due to the pore blockage. In the drying link, anhydrous calcium chloride or molecular sieve is often used for dehydration, but it is difficult to completely remove trace amounts of water which forms azeotrope with ether, and the regeneration of traditional drying agent is difficult, which increases the process cost. In the rectification stage, the conventional rectification column needs to separate impurities through multiple segmented operations, which is high in energy consumption and complicated in operation. Although vacuum rectification can reduce the boiling point, it is easy to cause incomplete separation of components due to the fluctuation of system pressure, resulting in insufficient purity of the distillate. In addition, the existing technology lacks a mechanism for the coordinated removal of multiple types of impurities, and the deep removal effect of trace amounts of peroxide and polar organic molecules is limited. Therefore, the present application provides an efficient ether purification process to solve the above technical problems. SUMMARY

[0004] The purpose of the present application is to provide an efficient ether purification process which can significantly remove peroxide, trace amounts of water, alcohol and organic impurities in ether, realize efficient separation and purification, and obtain ultra-high purity ether product. At the same time, the process is stable and efficient, and is suitable for the preparation of high-purity ether.

[0005] In order to achieve the above purpose, the present application adopts the following technical solutions:

[0006] An efficient ether purification process, comprising the following steps:

[0007] (1) passing ether through an adsorption column filled with composite filler, and dynamically adsorbing for 35-45 min at 10-15℃;

[0008] (2) adding a complexing agent to the effluent of step (1), stirring and reacting at -5-0°C for 1.5-2.2h to obtain a mixed solution;

[0009] (3) separating the mixed solution by a dividing wall column, first controlling the overhead temperature at 30-32°C under normal pressure with a reflux ratio (2.8-3.2):1, then reducing the system pressure to -0.094MPa--0.09MPa, controlling the main column section temperature at 25-28°C with a reflux ratio (6-8):1, collecting the distillate, filtering the distillate through a polytetrafluoroethylene membrane, and then packaging to obtain high-purity diethyl ether.

[0010] Preferably, the preparation step of the composite packing in step (1) is

[0011] S1, dissolving thiourea in ethanol, taking D101 macroporous resin and immersing it therein, oscillating and reacting at 50-55°C for 2-3h, then vacuum suction filtration, washing the filter cake with anhydrous ethanol and deionized water alternately for three times, and vacuum drying to obtain a modified resin;

[0012] S2, dispersing the modified resin and 4A molecular sieve powder in deionized water, adding alumina sol at 1-2mL / min, curing at 60-65°C for 1-2h, then centrifugal separation, washing the solid with ethanol, and drying to obtain an intermediate;

[0013] S3, dispersing the intermediate, 3-aminopropyltriethoxysilane and 3-glycidyl ether oxypropyltrimethoxysilane in toluene, adjusting the pH to 4.5-5.5, refluxing at 75-80°C for 3-4h, then extracting with acetone through a Soxhlet extractor, and vacuum drying the solid to obtain a precursor;

[0014] S4, placing the precursor in a tube furnace, programming the temperature under nitrogen atmosphere, i.e. constant temperature at 120-125°C for 0.8-1.2h, then constant temperature at 170-175°C for 0.8-1.2h, further constant temperature at 250-255°C for 0.8-1.2h, then burning at 350-370°C for 2-2.5h, natural cooling, crushing, and passing through a 100-150 mesh screen to obtain the composite packing.

[0015] Preferably, the preparation step of the complexing agent in step (2) is:

[0016] A1, taking SAA-15 mesoporous molecular sieve, dehydrating and activating at 500-540°C under nitrogen atmosphere for 3-5h, adding phosphotungstic acid into n-butanol, stirring at 35-45°C for 20-28h, then filtering, washing and drying to obtain an intermediate I;

[0017] A2, dissolving 18-crown-6 ether and 3-isocyanate propyl triethoxysilane in toluene, heating to 65-70°C under nitrogen protection, constant temperature reaction for 3-5h, then vacuum distillation, precipitation and drying and crushing to obtain 5-8μm intermediate II;

[0018] A3, dispersing intermediate I and intermediate II in ethanol, refluxing at 60~65℃ for 1~3h, then filtering, washing, vacuum drying, and crushing to get 1~5μm complexing agent.

[0019] Preferably, the amount of composite filler in step (1) is 22~25% of the weight of diethyl ether, and in step (2), 0.95~1.05 parts of complexing agent is added per 100 parts of diethyl ether.

[0020] Preferably, in step S1, 14~20 parts of thiourea, 55~65 parts of ethanol, and 10~15 parts of D101 macroporous resin are used.

[0021] Preferably, in step S2, 14~20 parts of modified resin, 5~8 parts of 4A molecular sieve powder, 40~50 parts of deionized water, and 18~20 parts of alumina sol are used.

[0022] Preferably, in step S3, 14~20 parts of intermediate, 3~4 parts of 3-aminopropyltriethoxysilane, 1~2 parts of 3-glycidyl ether propyltrimethoxysilane, and 50~60 parts of toluene are used.

[0023] Preferably, in step A1, 15~20 parts of SAA-15 mesoporous molecular sieve, 5~8 parts of phosphotungstic acid, and 80~85 parts of n-butanol are used.

[0024] Preferably, in step A2, 15~22 parts of 18-crown-6 ether, 5~8 parts of 3-isocyanate propyltriethoxysilane, and 40~60 parts of toluene are used.

[0025] Preferably, in step A3, 17~23 parts of intermediate I, 5~8 parts of intermediate II, and 60~65 parts of ethanol are used.

[0026] The beneficial effects of the present application are:

[0027] 1.The present application realizes the efficient and synergistic removal and deep purification of peroxides, trace water, alcohols and organic impurities in diethyl ether by constructing a purification process that synergizes adsorption of composite fillers, complexing agent reaction and dividing wall distillation. Based on the dynamic adsorption process of composite fillers and the specific reaction mechanism of complexing agents, combined with the gradient separation characteristics of the dividing wall distillation column, the decomposition of peroxides, the capture of trace water / alcohols and the directional removal of impurities are simultaneously completed under low-temperature operating conditions. The multi-stage pore structure of the composite fillers and the functional groups synergistically enhance the catalytic decomposition of peroxides and the preferential adsorption of water molecules, and the complexing agent efficiently locks the alcohol impurities. The precise switching of the dividing wall distillation column under normal pressure and reduced pressure modes realizes the efficient cutting of light component impurities and diethyl ether and the breakthrough separation of azeotropic systems. Finally, membrane filtration ensures product cleanliness. This process significantly improves the purification efficiency and product purity of diethyl ether, effectively solving the technical bottlenecks of poor adsorption selectivity, azeotropic dehydration difficulty, high distillation energy consumption and incomplete removal of trace impurities in traditional processes.

[0028] 2.The composite filler of the present application is synergistically designed by thiourea modified D101 macroporous resin and 4A molecular sieve powder. The thiourea group can adsorb and reduce peroxides in diethyl ether, and the 4A molecular sieve powder can efficiently remove trace water by its shape-selective adsorption characteristics. Both of them form a broad spectrum of capture ability for polar and non-polar impurities. The alumina sol treatment constructs a stable skeleton structure, enhances the mechanical strength and component compatibility of the filler, and the co-modification of silane coupling agents (3-aminopropyl triethoxysilane and 3-glycidyl ether oxypropyl trimethoxysilane) optimizes the interfacial properties and reduces the loss of active sites during the adsorption process. The hierarchical pore structure formed by programmed temperature calcination provides efficient mass transfer channels for impurity diffusion, avoiding pore blockage. Its high specific surface area significantly improves the adsorption capacity, while ensuring the structural stability and adsorption durability of the filler during the dynamic adsorption process.

[0029] 3.The complexing agent of the present application is synergistically constructed by SAA-15 mesoporous molecular sieve loaded with phosphotungstic acid and 18-crown-6 ether derivatives. The through mesoporous structure of SAA-15 provides an efficient path for mass transfer of impurities, and its high specific surface area enhances the dispersibility of phosphotungstic acid, increasing the adsorption and catalytic conversion capacity of polar impurities such as trace alcohols. The 18-crown-6 ether derivative can selectively complex small molecular organic impurities remaining in diethyl ether due to its unique cavity structure, forming a synergistic complexing effect with phosphotungstic acid to enhance the directional capture of trace impurities. The chemical combination of the two makes the complexing agent have both adsorption and complexing functions, efficiently locking residual impurities under low-temperature reaction conditions and avoiding the redissolution of impurities in the subsequent distillation process, significantly improving the purity of diethyl ether. DETAILED DESCRIPTION

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0031] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, and the experimental materials used, unless otherwise specified, were all purchased from conventional biochemical reagent stores. All quantitative experiments in the following examples were performed in triplicate, and the data are the average of the three replicates or the average ± standard deviation.

[0032] D101 macroporous resin, 4A molecular sieve and SAA-15 mesoporous molecular sieve were all purchased from Shanghai Yuanye Biotechnology Co., Ltd.

[0033] 4A molecular sieve, purchased from Shanghai Yuanye Biotechnology Co., Ltd.;

[0034] Alumina sol was purchased from Hefei Yihao New Material Technology Co., Ltd.

[0035] SAA-15 mesoporous molecular sieve was purchased from Shanghai Yuanye Biotechnology Co., Ltd.

[0036] Example 1

[0037] This embodiment provides a highly efficient purification process for diethyl ether, including the following steps:

[0038] (1) Pass diethyl ether through an adsorption column packed with composite packing material, using 22% of the weight of diethyl ether, and dynamically adsorb at 10℃ for 45 min;

[0039] (2) Add 0.95 parts of complexing agent to the effluent from step (1) at every 100 parts of ether, and stir at 120 rpm at 0°C for 2.2 h to obtain a mixture;

[0040] (3) The mixture is separated by a wall-distillation column. First, the temperature at the top of the column is controlled at 30°C under normal pressure and the reflux ratio is 2.8:1. Then, the system pressure is reduced to -0.09MPa, the temperature of the main column section is controlled at 25°C and the reflux ratio is 6:1. The fraction is collected and then filtered through a polytetrafluoroethylene membrane and sealed to obtain high-purity diethyl ether.

[0041] The preparation steps of the composite filler in step (1) are as follows:

[0042] S1. Dissolve 14 parts of thiourea in 55 parts of ethanol, and impregnate 10 parts of D101 macroporous resin in it. After reacting at 50°C with constant temperature shaking at 200 rpm for 3 hours, filter under reduced pressure. Wash the filter cake three times alternately with anhydrous ethanol and deionized water, and dry under vacuum to obtain the modified resin.

[0043] S2. Disperse 14 parts of modified resin and 5 parts of 4A molecular sieve powder in 40 parts of deionized water, add 18 parts of alumina sol dropwise at 1 mL / min while stirring at 200 rpm, ripen at 60℃ for 2 h, and then centrifuge to separate. Wash the solid with ethanol and dry to obtain the intermediate.

[0044] S3. Disperse 14 parts of intermediate, 3 parts of 3-aminopropyltriethoxysilane and 1 part of 3-glycidoxypropyltrimethoxysilane in 50 parts of toluene, adjust the pH to 4.5, reflux at 75°C for 4 h, and then extract with acetone using a Soxhlet extractor. Dry the solid under vacuum to obtain the precursor.

[0045] S4. Place the precursor in a tube furnace and heat it in a nitrogen atmosphere. Hold it at 120°C for 1.2 hours, then heat it to 170°C for 1.2 hours, then heat it to 250°C for 1.2 hours, then heat it to 350°C for 2.5 hours. After natural cooling, crush it and pass it through a 100-mesh sieve to obtain the composite filler.

[0046] The preparation steps of the complexing agent in step (2) are as follows:

[0047] A1. Take 15 parts of SAA-15 mesoporous molecular sieve and dehydrate and activate it in a nitrogen environment at 500℃ for 5h. Add it to 80 parts of n-butanol along with 5 parts of phosphotungstic acid. Stir at 200rpm at 35℃ for 28h. Filter, wash and dry to obtain intermediate I.

[0048] A2. Dissolve 15 parts of 18-crown-6 ether and 5 parts of 3-isocyanate propyltriethoxysilane in 40 parts of toluene, heat to 65°C under nitrogen protection, react at constant temperature for 5 hours, and then distill under reduced pressure, precipitate, dry and pulverize to obtain 8μm intermediate II.

[0049] A3. Disperse 17 parts of intermediate I and 5 parts of intermediate II in 60 parts of ethanol, reflux at 60°C for 3 hours, filter, wash, vacuum dry and pulverize to obtain a 5μm complexing agent.

[0050] Example 2

[0051] This embodiment provides a highly efficient purification process for diethyl ether, including the following steps:

[0052] (1) Pass diethyl ether through an adsorption column packed with composite packing material, using 23% of the weight of diethyl ether, and dynamically adsorb at 12℃ for 44 min;

[0053] (2) Add 0.99 parts of complexing agent to the effluent from step (1) at every 100 parts of ether, and stir at 130 rpm at -2℃ for 2.1 h to obtain a mixture;

[0054] (3) The mixture is separated by a wall-distillation column. First, the temperature at the top of the column is controlled at 31°C under normal pressure and the reflux ratio is 2.9:1. Then, the system pressure is reduced to -0.093MPa, the temperature of the main column section is controlled at 26°C and the reflux ratio is 7:1. The fraction is collected and then filtered through a polytetrafluoroethylene membrane and sealed to obtain high-purity diethyl ether.

[0055] The preparation steps of the composite filler in step (1) are as follows:

[0056] S1. Dissolve 15 parts of thiourea in 56 parts of ethanol, and impregnate 11 parts of D101 macroporous resin in it. After reacting at 52°C with constant temperature shaking at 210 rpm for 2.8 h, filter under reduced pressure. Wash the filter cake three times alternately with anhydrous ethanol and deionized water, and dry under vacuum to obtain the modified resin.

[0057] S2. Disperse 16 parts of modified resin and 7 parts of 4A molecular sieve powder in 42 parts of deionized water, add 19 parts of alumina sol dropwise at 1.2 mL / min while stirring at 210 rpm, ripen at 62℃ for 1.9 h, centrifuge to separate, wash the solid with ethanol and dry to obtain the intermediate.

[0058] S3. Disperse 16 parts of intermediate, 3.2 parts of 3-aminopropyltriethoxysilane and 1.2 parts of 3-glycidoxypropyltrimethoxysilane in 52 parts of toluene, adjust the pH to 4.8, reflux at 77°C for 3.8 h, then extract with acetone using a Soxhlet extractor, and dry the solid under vacuum to obtain the precursor.

[0059] S4. Place the precursor in a tube furnace and heat it in a nitrogen atmosphere. Hold it at 122℃ for 1.1 hours, then heat it to 172℃ for 1 hour, then heat it to 252℃ for 1 hour, and then heat it to 360℃ for 2.4 hours. After natural cooling, crush it and pass it through a 125-mesh sieve to obtain the composite filler.

[0060] The preparation steps of the complexing agent in step (2) are as follows:

[0061] A1. Take 18 parts of SAA-15 mesoporous molecular sieve and dehydrate and activate it in a nitrogen environment at 520℃ for 4.5h. Add it to 82 parts of n-butanol along with 6 parts of phosphotungstic acid. Stir at 210rpm at 38℃ for 27h. Filter, wash and dry to obtain intermediate I.

[0062] A2. Dissolve 18 parts of 18-crown-6 ether and 7 parts of 3-isocyanate propyltriethoxysilane in 45 parts of toluene. Under nitrogen protection, heat to 67°C and react at a constant temperature for 4.7 h. After vacuum distillation, precipitation, drying and pulverization, 7 μm intermediate II is obtained.

[0063] A3. Disperse 20 parts of intermediate I and 7 parts of intermediate II in 63 parts of ethanol, reflux at 62°C for 2.8 h, filter, wash, vacuum dry and pulverize to obtain a 4 μm complexing agent.

[0064] Example 3

[0065] This embodiment provides a highly efficient purification process for diethyl ether, including the following steps:

[0066] (1) Pass diethyl ether through an adsorption column packed with composite packing material, using 25% of the weight of diethyl ether, and dynamically adsorb at 15°C for 35 min;

[0067] (2) Add 1.05 parts of complexing agent to the effluent from step (1) at every 100 parts of ether, and stir at 150 rpm at -5℃ for 1.5 h to obtain a mixture;

[0068] (3) The mixture is separated by a wall-distillation column. First, the temperature at the top of the column is controlled at 32°C under normal pressure and the reflux ratio is 3.2:1. Then, the system pressure is reduced to -0.094MPa, the temperature of the main column section is controlled at 28°C and the reflux ratio is 8:1. The fraction is collected and then filtered through a polytetrafluoroethylene membrane and sealed to obtain high-purity diethyl ether.

[0069] The preparation steps of the composite filler in step (1) are as follows:

[0070] S1. Dissolve 20 parts of thiourea in 65 parts of ethanol, and impregnate 15 parts of D101 macroporous resin in it. After reacting at 55°C with constant temperature shaking at 240 rpm for 2 hours, filter under reduced pressure. Wash the filter cake three times alternately with anhydrous ethanol and deionized water, and dry under vacuum to obtain the modified resin.

[0071] S2. Disperse 20 parts of modified resin and 8 parts of 4A molecular sieve powder in 50 parts of deionized water, add 20 parts of alumina sol dropwise at 2 mL / min while stirring at 240 rpm, ripen at 65℃ for 1 h and then centrifuge to separate the solid. Wash the solid with ethanol and dry to obtain the intermediate.

[0072] S3. Disperse 20 parts of intermediate, 4 parts of 3-aminopropyltriethoxysilane and 2 parts of 3-glycidoxypropyltrimethoxysilane in 60 parts of toluene, adjust the pH to 5.5, reflux at 80°C for 3 h, and then extract with acetone using a Soxhlet extractor. Dry the solid under vacuum to obtain the precursor.

[0073] S4. Place the precursor in a tube furnace and program the temperature rise in a nitrogen atmosphere, i.e., keep it at 125℃ for 0.8h, then raise the temperature to 175℃ and keep it at 0.8h, then raise the temperature to 255℃ and keep it at 0.8h, then raise the temperature to 370℃ and burn for 2h. After natural cooling, crush it and pass it through a 150-mesh sieve to obtain the composite filler.

[0074] The preparation steps of the complexing agent in step (2) are as follows:

[0075] A1. Take 20 parts of SAA-15 mesoporous molecular sieve and dehydrate and activate it in a nitrogen environment at 540℃ for 3 hours. Add it to 85 parts of n-butanol along with 8 parts of phosphotungstic acid. Stir at 280 rpm at 45℃ for 20 hours. Then filter, wash and dry to obtain intermediate I.

[0076] A2. Dissolve 22 parts of 18-crown-6 ether and 8 parts of 3-isocyanate propyltriethoxysilane in 60 parts of toluene. Under nitrogen protection, heat to 70°C and react at a constant temperature for 3 hours. After vacuum distillation, precipitation, drying and pulverization, 8 μm intermediate II is obtained.

[0077] A3. Disperse 23 parts of intermediate I and 8 parts of intermediate II in 65 parts of ethanol, reflux at 65°C for 1 hour, filter, wash, vacuum dry and pulverize to obtain a 1 μm complexing agent.

[0078] Example 4

[0079] This embodiment provides a highly efficient purification process for diethyl ether, including the following steps:

[0080] (1) Pass the diethyl ether through an adsorption column packed with composite packing material, using 25% of the weight of the diethyl ether, and dynamically adsorb at 15°C for 40 min;

[0081] (2) Add 1.02 parts of complexing agent to the effluent from step (1) at every 100 parts of ether, and stir at 150 rpm for 1.8 h at 0 °C to obtain a mixture;

[0082] (3) The mixture is separated by a wall-distillation column. First, the temperature at the top of the column is controlled at 32°C under normal pressure and the reflux ratio is 3.2:1. Then, the system pressure is reduced to -0.094MPa, the temperature of the main column section is controlled at 28°C and the reflux ratio is 8:1. The fraction is collected and then filtered through a polytetrafluoroethylene membrane and sealed to obtain high-purity diethyl ether.

[0083] The preparation steps of the composite filler in step (1) are as follows:

[0084] S1. Dissolve 20 parts of thiourea in 65 parts of ethanol, and impregnate 14 parts of D101 macroporous resin in it. After reacting at 55°C with constant temperature shaking at 240 rpm for 2.4 h, filter under reduced pressure. Wash the filter cake three times alternately with anhydrous ethanol and deionized water, and dry under vacuum to obtain the modified resin.

[0085] S2. Disperse 18 parts of modified resin and 5 parts of 4A molecular sieve powder in 50 parts of deionized water, add 20 parts of alumina sol dropwise at 2 mL / min while stirring at 240 rpm, ripen at 65℃ for 1.5 h, and then centrifuge to separate the solid. Wash the solid with ethanol and dry to obtain the intermediate.

[0086] S3. Disperse 18 parts of intermediate, 3.5 parts of 3-aminopropyltriethoxysilane and 1.6 parts of 3-glycidoxypropyltrimethoxysilane in 60 parts of toluene, adjust the pH to 5.5, reflux at 78°C for 3.2 h, then extract with acetone using a Soxhlet extractor, and dry the solid under vacuum to obtain the precursor.

[0087] S4. Place the precursor in a tube furnace and program the temperature rise in a nitrogen atmosphere, i.e., keep it at 124℃ for 1 hour, then raise the temperature to 170℃ and keep it at 0.8 hours, then raise the temperature to 250℃ and keep it at 0.8 hours, then raise the temperature to 360℃ and burn for 2 hours. After natural cooling, crush it and pass it through a 150-mesh sieve to obtain the composite filler.

[0088] The preparation steps of the complexing agent in step (2) are as follows:

[0089] A1. Take 20 parts of SAA-15 mesoporous molecular sieve and dehydrate and activate it in a nitrogen environment at 540℃ for 4 hours. Add it to 85 parts of n-butanol along with 8 parts of phosphotungstic acid. Stir at 280 rpm at 45℃ for 24 hours. Then filter, wash and dry to obtain intermediate I.

[0090] A2. Dissolve 20 parts of 18-crown-6 ether and 7 parts of 3-isocyanate propyltriethoxysilane in 60 parts of toluene. Under nitrogen protection, heat to 70°C and react at a constant temperature for 3.5 h. After vacuum distillation, precipitation, drying and pulverization, 5 μm intermediate II is obtained.

[0091] A3. Disperse 22 parts of intermediate I and 5 parts of intermediate II in 65 parts of ethanol, reflux at 65°C for 1.4 h, filter, wash, vacuum dry and pulverize to obtain a 2 μm complexing agent.

[0092] Comparative Example 1

[0093] A highly efficient purification process for diethyl ether differs from Example 4 in that step S2 is omitted in the preparation of the composite filler. That is, the modified resin and 4A molecular sieve powder are not dispersed in deionized water and alumina sol is not added dropwise. Step S3 is carried out directly from the modified resin obtained in step S1. Other conditions are the same as in Example 4.

[0094] Comparative Example 2

[0095] A high-efficiency purification process for diethyl ether differs from Example 4 in that only steps S2 and S4 are performed in the preparation of the composite filler, i.e. steps S1 and S3 are omitted. Unmodified D101 macroporous resin is directly used to replace the modified resin. It is dispersed in deionized water with 4A molecular sieve powder in a certain proportion, and alumina sol is added dropwise. After aging, it is centrifuged, washed and dried to obtain the intermediate of step S2. Then, it is directly subjected to the programmed temperature rise calcination treatment of step S4. Finally, the composite filler is obtained by sieving. Other conditions are the same as in Example 4.

[0096] Comparative Example 3

[0097] A highly efficient purification process for diethyl ether differs from Example 4 in that the thiourea modification in step S1 is not performed during the preparation of the composite filler; that is, unmodified D101 macroporous resin is directly used for step S2, while other conditions are the same as in Example 4.

[0098] Comparative Example 4

[0099] A high-efficiency purification process for diethyl ether differs from Example 4 in that no complexing agent is added in step (2), i.e., the step of adding a complexing agent to the effluent is omitted, and the effluent is directly separated by a wall distillation column. Other conditions are the same as in Example 4.

[0100] Comparative Example 5

[0101] A highly efficient purification process for diethyl ether differs from Example 4 in that intermediate I is directly used as a complexing agent in step (2), replacing the complete complexing agent. That is, steps A2 and A3 for preparing the complexing agent are omitted, while other conditions are the same as in Example 4.

[0102] Comparative Example 6

[0103] A highly efficient purification process for diethyl ether differs from Example 4 in that phosphotungstic acid is not added in step A1 of the complexing agent preparation process. Instead, only SAA-15 mesoporous molecular sieve is used for dehydration and activation before adding n-butanol without adding phosphotungstic acid. The resulting product is used as intermediate I for subsequent steps, and other conditions are the same as in Example 4.

[0104] Performance verification test:

[0105] The performance of the high-efficiency purification process of diethyl ether in Examples 1-4 and Comparative Examples 1-6 was tested, and the test results are shown in Table 1.

[0106] Table 1

[0107] Test item Peroxide ppm Moisture ppm Ethanol ppm Ethyl ether purity % Example 1 0.82 4.23 8.56 99.992 Example 2 0.76 3.82 7.25 99.993 Example 3 0.69 3.55 6.94 99.995 Example 4 0.55 3.14 6.33 99.996 Comparative Example 1 1.95 28.65 32.10 99.872 Comparative Example 2 15.38 37.43 48.77 99.521 Comparative Example 3 12.77 8.96 35.69 99.643 Comparative Example 4 1.22 5.14 45.88 99.782 Comparative Example 5 0.82 4.53 28.37 99.841 Comparative Example 6 0.97 4.86 32.72 99.802

[0108] As can be seen from the table data, the purification effect of Examples 1 to 4 is significantly better than that of the comparative examples. Among them, Example 4 has the best indicators, with peroxides at only 0.55 ppm, water at 3.14 ppm, ethanol at 6.33 ppm, and a purity of up to 99.996%. This shows that through the synergistic effect of dynamic adsorption of composite packing, low-temperature reaction of complexing agent and wall distillation, peroxides, trace amounts of water and alcohol impurities in diethyl ether can be effectively removed, achieving deep purification.

[0109] The performance data of each comparative example were poor. Comparative Example 1 omitted the alumina sol treatment step in the preparation of the composite filler, resulting in insufficient structural stability of the filler, decreased impurity adsorption capacity, and significantly increased peroxide, moisture, and ethanol content, with purity dropping to 99.872%. Comparative Example 2 did not undergo thiourea modification and silane coupling modification, and the composite filler lacked functional groups for targeted adsorption of peroxides, resulting in a peroxide content as high as 15.38 ppm and a purity of only 99.521%. Comparative Example 3 lacked thiourea modification, resulting in incomplete removal of peroxides and high ethanol residue. Comparative Example 4 did not add a complexing agent, and could not effectively capture residual alcohols, resulting in an ethanol content of 45.88 ppm. Comparative Examples 5 and 6 had incomplete complexing agent preparation, lacking 18-crown-6 ether derivatives or phosphotungstic acid, affecting the selective complexation of ethanol, and the ethanol residue was significantly higher than in the examples.

[0110] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A highly efficient purification process for diethyl ether, characterized in that, Includes the following steps: (1) Pass diethyl ether through an adsorption column packed with composite packing material and dynamically adsorb it at 10~15℃ for 35~45 min; (2) Add a complexing agent to the effluent from step (1) and stir at -5~0℃ for 1.5~2.2h to obtain a mixture; (3) The mixture is separated by a wall distillation column. First, it is separated at atmospheric pressure, and then the system pressure is reduced to separate it. The fraction is collected and then filtered through a polytetrafluoroethylene membrane and packaged to obtain high-purity diethyl ether.

2. The efficient purification process for diethyl ether according to claim 1, characterized in that, The preparation steps of the composite filler in step (1) are as follows: S1. Dissolve thiourea in ethanol, impregnate D101 macroporous resin in it, filter under reduced pressure after reaction, wash the filter cake alternately with anhydrous ethanol and deionized water, and dry under vacuum to obtain modified resin. S2. Disperse the modified resin and 4A molecular sieve powder in deionized water, add alumina sol dropwise, ripen, centrifuge, wash the solid with ethanol and dry to obtain the intermediate. S3. The intermediate, 3-aminopropyltriethoxysilane and 3-glycidoxypropyltrimethoxysilane were dispersed in toluene, the pH was adjusted, the reaction was refluxed and then extracted with acetone using a Soxhlet extractor, and the solid was dried under vacuum to obtain the precursor. S4. Place the precursor in a tube furnace and heat it in a nitrogen atmosphere. Perform multiple constant temperature treatments in sequence, then heat and calcine it. After natural cooling, crush it and pass it through a sieve to obtain the composite filler.

3. The efficient purification process for diethyl ether according to claim 1, characterized in that, The preparation steps of the complexing agent in step (2) are as follows: A1. Take SAA-15 mesoporous molecular sieve, dehydrate and activate it, add it with phosphotungstic acid into n-butanol, stir, filter, wash and dry to obtain intermediate I; A2. Dissolve 18-crown-6 ether and 3-isocyanate propyltriethoxysilane in toluene, react under nitrogen protection, and then distill under reduced pressure, precipitate, dry and pulverize to obtain intermediate II; A3. Intermediate I and Intermediate II are dispersed in ethanol, refluxed, filtered, washed, vacuum dried, and pulverized to obtain the complexing agent.

4. The efficient purification process for diethyl ether according to claim 1, characterized in that, In step (1), the amount of composite filler used is 22-25% of the weight of diethyl ether, and in step (2), 0.95-1.05 parts of complexing agent are added for every 100 parts of diethyl ether.

5. The efficient purification process for diethyl ether according to claim 2, characterized in that, In step S1, the components by weight are 14-20 parts thiourea, 55-65 parts ethanol, and 10-15 parts D101 macroporous resin.

6. The efficient purification process for diethyl ether according to claim 2, characterized in that, In step S2, the components by weight are 14-20 parts modified resin, 5-8 parts 4A molecular sieve powder, 40-50 parts deionized water, and 18-20 parts alumina sol.

7. The efficient purification process for diethyl ether according to claim 2, characterized in that, In step S3, the components by weight are 14-20 parts of intermediate, 3-4 parts of 3-aminopropyltriethoxysilane, 1-2 parts of 3-glycidyl etheroxypropyltrimethoxysilane, and 50-60 parts of toluene.

8. The efficient purification process for diethyl ether according to claim 3, characterized in that, In step A1, the components by weight are 15-20 parts of SAA-15 mesoporous molecular sieve, 5-8 parts of phosphotungstic acid, and 80-85 parts of n-butanol.

9. The efficient purification process for diethyl ether according to claim 3, characterized in that, In step A2, the ingredients are 15-22 parts by weight of 18-crown-6 ether, 5-8 parts by weight of 3-isocyanate propyltriethoxysilane, and 40-60 parts by weight of toluene.

10. The efficient purification process for diethyl ether according to claim 3, characterized in that, In step A3, the components are 17-23 parts by weight of intermediate I, 5-8 parts by weight of intermediate II, and 60-65 parts by weight of ethanol.