An ammoximation mixing and reaction system and process

Abstract

An ammoximation mixing and reaction system and process, the ammoximation mixing and reaction system comprising: scheme one: comprising 1#, 2# microchannel mixing reactor, reaction device, 1#, 2# membrane filter;Scheme two: on the basis of scheme one, the 2# microchannel mixing reactor is replaced by a membrane mixing reactor;Scheme three: on the basis of scheme one, a membrane mixing reactor is connected in series after the 2# microchannel mixing reactor.The application also discloses an ammoximation mixing and reaction process.The ammoximation mixing and reaction system of the application is simple in structure, green in environment protection, safe and reliable.The ammoximation mixing and reaction process of the application is low in t-butyl alcohol consumption, low in energy consumption for separating t-butyl alcohol, high in utilization rate of hydrogen peroxide, accurate in reaction temperature control, good in raw material mixing effect, high in conversion rate of cyclohexanone, high in selectivity of cyclohexanone oxime, free from other byproduct generation, simple in process, low in cost and suitable for industrial production.

Description

Technical Field

[0001] This invention specifically relates to an ammonium oxime mixing and reaction system and process. Background Technology

[0002] Industrially, the aminooximeation of cyclohexanone often employs a TS-1 / H2O2 / tert-butanol-water system. Since cyclohexanone, H2O2, and TS-1 all require homogeneous or pseudo-homogeneous conditions for reaction, traditional processes necessitate the use of large quantities of tert-butanol as a co-solvent, resulting in the following technical drawbacks: (1) Huge solvent consumption: The mass ratio of tert-butanol to cyclohexanone oxime is 2:1, that is, 420-500 kg of tert-butanol is consumed per ton of cyclohexanone oxime, accounting for 8-10% of the raw material cost; (2) High energy consumption for recovery: Tert-butanol forms a low-boiling azeotrope with water, requiring three distillation towers: extraction tower, dehydration tower, and refining tower. The steam consumption is 0.9 to 1.1 t / t oxime, which is equivalent to about 110 kg of standard coal. (3) Safety and environmental pressure: The flash point of tert-butanol is 11 ℃, and the equipment needs to be explosion-proof Class IIC; at the same time, the treatment costs of high COD wastewater (>1500 mg / L) and by-product ammonium sulfate continue to rise; (4) Excessive hydrogen peroxide: To prevent local depletion, n(H2O2) / n(cyclohexanone) is usually 1.14. Excessive H2O2 will decompose under alkaline conditions, which is both wasteful and increases the tail gas treatment load.

[0003] In the past decade, although some studies have used microchannels for the aminooximation of cyclohexanone, the high-tert-butanol formulation is still used. The reaction time is shortened, but the fundamental problems of solvent dosage and H2O2 excess are not addressed. The main reason is that in order to maintain the homogeneous system in the microchannel, the traditional view is that a large amount of tert-butanol must be used and H2O2 is added at a single point. This results in a high instantaneous concentration of H2O2 and rapid decomposition, leading to low utilization of hydrogen peroxide.

[0004] In response to the aforementioned technical shortcomings, the market urgently needs a "double-low" process: (1) The amount of tert-butanol used was reduced by one order of magnitude (<0.50 kg / kg oxime); (2) The stoichiometric ratio of H2O2 is ≤1.14, and the utilization rate is >98%; (3) Maintain cyclohexanone conversion rate > 99.9% and cyclohexanone oxime selectivity > 99.9%.

[0005] The key to achieving the above goals lies in: (1) How to uniformly dissolve cyclohexanone and disperse H2O2 in a very low solvent system within milliseconds; (2) How to remove instantaneous heat release and prevent local temperature rise > 1 ℃; (3) How to monitor and control online to prevent crystallization and oil phase from clogging microchannels.

[0006] The difficulty that existing technologies cannot solve lies in: (1) Cyclohexanone-aqueous phase separation is very likely to occur in the low tert-butanol system, and traditional mechanical stirring cannot achieve microscale uniformity. (2) Single-point injection of H2O2 can easily form a high-concentration zone in the millisecond-level reaction, and the decomposition byproduct O2 can induce cavitation and disrupt the flow pattern; (3) There is a lack of real-time, rapid concentration detection methods that do not cross-contaminate with the liquid, making it impossible to control the H2O2 replenishment in a closed loop.

[0007] CN112426958A discloses an ammonia oxime reaction separation device and method, which is a homogeneous ammonia oxime process using microchannels and membrane mixers to mix reactants, and the product is separated into turbid liquid and clear liquid at the discharge port. However, the product of this method is separated into clear liquid and turbid liquid. The clear liquid is a transparent product liquid with almost no catalyst and is directly sent downstream, while the turbid liquid is a concentrated slurry enriched with catalyst and is recycled back to the reactor. Since there is no mixing of oil and water phases in the turbid liquid, the oil phase enrichment that causes blockage during filtration will not occur, and there is no need to solve the problem of mixer blockage. In addition, the utilization rate of hydrogen peroxide as raw material is low, the conversion rate of cyclohexanone is low, and the selectivity of cyclohexanone oxime is low.

[0008] In summary, there is an urgent need to find a simple, environmentally friendly, safe and reliable ammonium oxime mixing and reaction system, which features extremely low tert-butanol usage, low energy consumption for tert-butanol separation, high hydrogen peroxide utilization, good raw material mixing effect, high cyclohexanone conversion rate, high selectivity for cyclohexanone oxime, precise reaction temperature control, no other byproducts generated, simple process, low cost, and is suitable for industrial production of ammonium oxime mixing and reaction. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to overcome the above-mentioned defects of the prior art and provide a simple, green, environmentally friendly, safe and reliable ammonium oxime mixing and reaction system.

[0010] The technical problem to be further solved by the present invention is to overcome the above-mentioned defects of the prior art and provide an ammonia oxime mixing and reaction process with extremely low tert-butanol dosage, low energy consumption for tert-butanol separation, high hydrogen peroxide utilization rate, precise control of reaction temperature, good raw material mixing effect, high conversion rate of cyclohexanone, high selectivity of cyclohexanone oxime, no other by-products generated, simple process, low cost, and suitable for industrial production.

[0011] The technical solution adopted by this invention to solve its technical problem is as follows: an ammonium oxime mixing and reaction system. Option 1: Includes microchannel mixing reactors #1 and #2, a reaction apparatus, and membrane filters #1 and #2; the outlet of microchannel mixing reactor #1 is connected to the mixing inlet of microchannel mixing reactor #2, and the outlet of microchannel mixing reactor #2 is connected to the inlet at the top of the reaction apparatus; the oil phase outlet in the middle of the reaction apparatus is connected to the tube-side inlet of membrane filter #2, and the tube-side outlet of membrane filter #2 is connected to the mixing inlet of microchannel mixing reactor #2; the aqueous phase outlet at the bottom of the reaction apparatus is connected to the tube-side inlet of membrane filter #1, and the tube-side outlet of membrane filter #1 is connected to the mixing inlet of microchannel mixing reactor #1; hydrogen peroxide inlet is provided on microchannel mixing reactor #2; both membrane filters #1 and #2 have shell-side outlets in their middle sections. Option 2: Based on Option 1, replace the No. 2 microchannel mixing reactor with a membrane mixing reactor. The membrane mixing reactor has a hydrogen peroxide inlet in the middle of the outer side of the shell. The outlet of the No. 1 microchannel mixing reactor is connected to the tube-side inlet of the membrane mixing reactor, and the tube-side outlet of the membrane mixing reactor is connected to the inlet at the top of the reaction device. Option 3: Based on Option 1, a membrane mixing reactor is connected in series after the No. 2 microchannel mixing reactor. The membrane mixing reactor has a hydrogen peroxide inlet in the middle of the outer side of the shell. The outlet of the No. 2 microchannel mixing reactor is connected to the inlet of the membrane mixing reactor, and the outlet of the membrane mixing reactor is connected to the inlet at the top of the reaction device.

[0012] The working process of the ammonium oxime mixing and reaction system of the present invention is as follows: Option 1: First, dissolve and mix cyclohexanone and tert-butanol, then feed them along with ammonia into a No. 1 microchannel mixing reactor. Under preheating by a heat source in the heating jacket, thorough mixing and emulsification are performed. The resulting premixed solution is then fed into a No. 2 microchannel mixing reactor. Simultaneously, hydrogen peroxide is added through the hydrogen peroxide inlet of the No. 2 microchannel mixing reactor to react with the premixed solution. The cooling jacket cools the exothermic reaction. The resulting pre-reaction solution is then fed into the reaction apparatus. During the reaction, the solid catalyst precipitates downwards with the aqueous phase in a cyclone separator. The reaction products separate into oil and aqueous phases: the oil phase flows out from the middle of the reaction apparatus and is pumped into a No. 2 membrane filter via a circulating pump. Under heating by a heat source in the heating jacket... The process involves filtration. The oil phase containing a large amount of cyclohexanone oxime is filtered out from the shell-side outlet of membrane filter #2 and sent to the alcohol recovery tower. The intercepted solid catalyst, excess reactants, and products are separated as oil phase concentrate and flow out from the tube-side outlet of membrane filter #2, then sent to microchannel mixing reactor #2. The aqueous phase containing solid catalyst flows out from the bottom of the reactor and is pumped into membrane filter #1 via a circulating pump. Under the heating of the heat source in the heating jacket, the process is carried out. The aqueous phase containing a small amount of cyclohexanone oxime is filtered out from the shell-side outlet of membrane filter #1 and sent to the alcohol recovery tower. The intercepted solid catalyst and excess reactants are separated as aqueous phase concentrate and flow out from the tube-side outlet of membrane filter #1, then sent to microchannel mixing reactor #1.

[0013] Option 2: The only difference between this option and Option 1 is that the obtained premixed solution is fed into the tube-side inlet of the membrane mixing reactor. Hydrogen peroxide is added through the hydrogen peroxide inlet located in the middle of the outer shell of the membrane mixing reactor. Under pressure, the hydrogen peroxide is cut into microdroplets through the micropores of the tubular membrane wall and enters the inner side of the tubular membrane, where it undergoes a pre-reaction with the premixed solution. The cooling jacket cools the exothermic reaction, and then the pre-reacted solution is sent into the reaction apparatus. Everything else is the same as Option 1.

[0014] Option 3: The only difference between this option and Option 1 is that the obtained pre-reaction liquid is further fed into the tube-side inlet of the membrane mixing reactor. Simultaneously, hydrogen peroxide is added through the hydrogen peroxide inlet located in the middle of the outer shell of the membrane mixing reactor. Under pressure, the hydrogen peroxide permeates through the micropores of the tubular membrane wall, is cut into microdroplets, and enters the inner side of the tubular membrane, where it undergoes an initial reaction with the pre-reaction liquid. The cooling jacket cools the exothermic reaction, and then the initial reaction liquid is fed into the reaction apparatus. Everything else is the same as Option 1.

[0015] When the system is running stably, solid catalysts are uniformly distributed in the microchannel mixing reactor, membrane mixing reactor, and reaction device, enabling efficient mixed catalytic reactions to occur in each part.

[0016] The inventive concept of this system is as follows: Cyclohexanone is uniformly dispersed in the reaction system through the mixing and emulsification effects of a microchannel mixing reactor and pre-reaction with hydrogen peroxide, avoiding cyclohexanone stratification. This allows for normal operation even with a low ratio of tert-butanol to cyclohexanone, reducing the concentration of tert-butanol solvent in the reaction product and thus reducing energy consumption in subsequent solvent evaporation processes. Pre-reaction in the microchannel mixing reactor improves the efficiency of subsequent reactions. The built-in cyclone separator separates most of the aqueous phase, reducing the water content in the oil phase and effectively reducing the amount of cyclohexanone oxime precipitated when the oil phase passes through the membrane filter. By controlling the temperature of the membrane filter and using an online cyclohexanone oxime detector to determine whether an increase in tert-butanol addition is needed, the precipitation of cyclohexanone oxime within the membrane filter can prevent clogging. Furthermore, by adding hydrogen peroxide in stages, uniform addition of hydrogen peroxide is achieved, avoiding ineffective decomposition of hydrogen peroxide due to excessively high local concentrations, reducing the consumption of hydrogen peroxide in the reaction system, and preventing excessive oxidation of cyclohexanone and cyclohexanone oxime with hydrogen peroxide to generate byproduct impurities when local hydrogen peroxide concentration is too high. This further improves the selectivity of the reaction, and the raw materials can undergo pre-reaction while being mixed.

[0017] Preferably, the microchannel mixing reactor includes passive chaotic microchannels, etc. A microemulsion system of "instantaneous homogeneity-rapid phase separation" can be constructed within the microchannel, thereby enabling the materials to be uniformly mixed and ultimately forming a heterogeneous microemulsion system. This system can be maintained in the pipeline and reactor for a relatively long time, allowing the reaction to proceed more fully.

[0018] Preferably, the Reynolds number of the passive chaotic microchannel is 100–2500, and the channel diameter is 0.5–5.0 mm. The Reynolds number is limited to prevent the increase of byproducts. When the Reynolds number is too low, laminar flow dominates, resulting in long diffusion distances, low mass and heat transfer efficiency between materials, and an excess of local reactants leading to an increase in side reactions. When the Reynolds number is too high, turbulent pulsations break H2O2 into more micro-clusters, and the instantaneous high concentration on the catalyst surface leads to an increase in side reactions. Furthermore, an excessively high Reynolds number will cause an excessive pressure drop.

[0019] Preferably, the passive chaotic microchannel includes T-shaped, Y-shaped, heart-shaped, serpentine, herringbone, or spiral channels. More preferably, the passive chaotic microchannel is heart-shaped.

[0020] Preferably, the heating jacket of the No. 1 microchannel mixing reactor has a heat source inlet near the discharge port and a heat source outlet near the mixing inlet. Preheating the microchannel mixing reactor via the heating jacket is more conducive to the subsequent pre-reaction.

[0021] Preferably, one or more microchannel mixing reactors can be connected in series or parallel. Connecting multiple microchannel mixing reactors in series or parallel achieves better mixing and a more complete reaction.

[0022] Preferably, the cooling jacket of the No. 2 microchannel mixing reactor has a cold water inlet near the discharge port and a cold water outlet near the mixing inlet. The purpose of cooling is to prevent the reaction from being violently exothermic, causing the temperature to become too high and thus resulting in side reactions.

[0023] Preferably, the microchannel mixing reactor is equipped with an ultrasonic device. This ultrasonic device can perform online ultrasonic cleaning, preventing equipment clogging, thereby effectively extending the continuous operating cycle of the equipment and reducing the frequency of shutdowns for cleaning.

[0024] Preferably, the reaction apparatus is equipped with a stirring device and a cyclone separator.

[0025] Preferably, the stirring blades of the stirring device are located at a height of 1 / 3 to 1 / 2 from the bottom of the reaction device, and the top of the cyclone separator is located at a height of 1 / 4 to 1 / 3 from the bottom of the reaction device and slightly lower than the stirring blades.

[0026] Preferably, the cooling jacket of the reaction apparatus has a cold water inlet on the lower side and a cold water outlet on the upper side. The purpose of cooling is to prevent the reaction from being violently exothermic, causing the temperature to become too high and thus resulting in side reactions.

[0027] Preferably, a circulation pump is provided between the oil phase outlet and the water phase outlet of the reaction device and the inlet of the membrane filter.

[0028] Preferably, the membrane filter is a tubular filter element with open ends.

[0029] Preferably, the tubular filter element consists of a precision filter layer, a transition layer, and a support layer from the outside to the inside.

[0030] Preferably, the precision filter layer, transition layer, and support layer include ceramic membranes, metal membranes, or organic membranes. The organic membranes include polyvinylidene fluoride membranes, polytetrafluoroethylene membranes, nylon membranes, polypropylene membranes, polyethylene membranes, polyethersulfone membranes, or polysulfone membranes.

[0031] Preferably, the pore sizes of the precision filter layer, transition layer, and support layer gradually increase.

[0032] Preferably, the pore size of the precision filter layer is 0.05 to 10.00 μm (more preferably 0.05 to 5.00 μm).

[0033] Preferably, the thickness of the precision filter layer, when it is a ceramic membrane, is 0.01 to 0.05 mm.

[0034] Preferably, the thickness of the precision filter layer when it is a metal membrane is 0.1 to 0.5 mm.

[0035] Preferably, the pore size of the transition layer is 1 to 10 μm.

[0036] Preferably, the number of layers in the transition layer is 1 to 8.

[0037] Preferably, when the transition layer is a ceramic film, the thickness of each layer is 0.1 to 0.5 mm.

[0038] Preferably, when the transition layer is a metal film, the thickness of each layer is 0.3 to 0.8 mm.

[0039] Preferably, the pore size of the support layer is 10–50 μm.

[0040] Preferably, the thickness of the support layer, whether it is a ceramic film or a metal film, is 0.5 to 1.2 mm.

[0041] Preferably, the heating jackets of membrane filters #1 and #2 have a heat source inlet at the near-tube outlet and a heat source outlet at the near-tube inlet. Heating is used to prevent oxime precipitation due to temperature drop, which could cause membrane filter fouling.

[0042] Preferably, an online cyclohexanone oxime detector is installed after the outlet of the No. 2 membrane filter tube. Since this invention reduces the amount of tert-butanol, to prevent the precipitation of cyclohexanone oxime within the membrane filter and subsequent clogging, strict temperature control and monitoring of the cyclohexanone oxime concentration are necessary to determine whether the amount of tert-butanol needs to be increased. The online cyclohexanone oxime detector is equipped with an infrared spectrometer and a densitometer, employing a dual detection principle of infrared and densitometric methods.

[0043] Preferably, a pressure regulating valve is provided between the tube outlet of the No. 1 and No. 2 membrane filters and the mixing inlet of the No. 1 and No. 2 microchannel mixing reactors.

[0044] Preferably, the membrane mixing reactor can be one or more connected in series. By connecting multiple membrane mixing reactors in series, hydrogen peroxide can be rapidly and uniformly added at each site, and the reaction is immediately initiated during the mixing process in the tubular membrane. By replenishing hydrogen peroxide stepwise and continuously at the front and rear sections, the continuous and uniform reaction of hydrogen peroxide is achieved, thereby ensuring that the hydrogen peroxide reaction is complete and avoiding solvent waste or excess.

[0045] Preferably, the membrane mixing reactor includes a shell; a tubular membrane is sleeved inside the shell; a shell side is formed between the outer side of the tubular membrane and the shell, and a tube side is formed inside the tubular membrane; a spiral guide vane is provided inside the tube side; the beginning and end ends of the shell and the tubular membrane are sealed by a tube sheet.

[0046] Preferably, the spiral guide vane includes a segmented and recombinant guide vane, etc.

[0047] Preferably, the segmented and recombinant flow guide includes SV, SK, SX, SH, or SL type flow guides, etc. More preferably, the segmented and recombinant flow guide is an SK type flow guide.

[0048] Preferably, the diameter of the tubular membrane is 2 to 100 mm (more preferably 10 to 60 mm), and the length is 30 to 5000 mm, the same as the length of the tubular shell.

[0049] Preferably, the tubular membrane includes single-channel or multi-channel microporous membranes, etc.

[0050] Preferably, the pore size of the microporous membrane is 10 nm to 100 μm (more preferably 100 nm to 10 μm). At this pore size, good dispersion can be ensured, thereby achieving a good mixing effect.

[0051] Preferably, the microporous membrane comprises one or more of the following: a metal membrane, a ceramic membrane, or an organic membrane. The organic membrane includes polyvinylidene fluoride (PVDF) membranes, polytetrafluoroethylene (PTFE) membranes, nylon membranes, polypropylene membranes, polyethylene membranes, polyethersulfone (PES) membranes, or polysulfone membranes. More preferably, the microporous membrane is a ceramic membrane.

[0052] Preferably, the cooling jacket of the membrane mixing reactor has a cold water inlet near the discharge port and a cold water outlet near the feed port. The purpose of cooling is to prevent the reaction from being violently exothermic, causing the temperature to become too high and thus resulting in side reactions.

[0053] Preferably, the membrane mixing reactor is equipped with an ultrasonic device. This ultrasonic device can perform online ultrasonic cleaning, preventing equipment clogging, thereby effectively extending the continuous operating cycle of the equipment and reducing the frequency of shutdowns for cleaning.

[0054] Preferably, a filter device No. 1 is provided before the No. 1 microchannel mixing reactor, and a filter device No. 2 is provided before the No. 2 microchannel mixing reactor and / or membrane mixing reactor.

[0055] Preferably, both the No. 1 and No. 2 filter devices have a feed inlet on one side.

[0056] Preferably, the outlet on the other side of the No. 1 filter is connected to the mixing inlet of the No. 1 microchannel mixing reactor, and the outlet on the other side of the No. 2 filter is connected to the hydrogen peroxide inlet of the No. 2 microchannel mixing reactor and / or the hydrogen peroxide inlet of one or more membrane mixing reactors connected in series at the middle of the outer side of the shell.

[0057] Preferably, the layered filter element in the filtration device consists of a support layer, a transition layer, and a precision filter layer, sequentially from the inlet to the outlet.

[0058] Preferably, in the filtration device, the precision filter layer, the transition layer, and the support layer are all ceramic membranes or organic membranes, etc.

[0059] Preferably, the properties of the precision filter layer, transition layer, and support layer in the filtration device are the same as those of the membrane filter.

[0060] Preferably, a flow regulating valve and a flow meter are sequentially installed between the outlet of the No. 2 filter device and the hydrogen peroxide inlet of the No. 2 microchannel mixing reactor or membrane mixing reactor.

[0061] Preferably, the heating jacket of the filter device has a heat source inlet near the discharge port and a heat source outlet near the feed port.

[0062] Preferably, all connecting pipelines are equipped with temperature and pressure display instruments.

[0063] This invention utilizes a heating jacket or a cooling jacket to achieve heat exchange, thereby enabling precise control of the reaction temperature.

[0064] The technical solution adopted by the present invention to further solve its technical problem is as follows: an ammonium oxime mixing and reaction process, comprising the following steps: (1) After dissolving and mixing cyclohexanone and tert-butanol, it is fed into the No. 1 microchannel mixing reactor along with ammonia material for mixing and emulsification to obtain a premixed solution; (2) The premixed liquid obtained in step (1) is sent into the No. 2 microchannel mixing reactor or membrane mixing reactor, hydrogen peroxide is added, and pre-reaction is carried out to obtain the pre-reaction liquid; (3) The pre-reaction liquid obtained in step (2) is sent into the reaction device, a solid catalyst is added, and an oxime reaction is carried out to obtain an oil phase and an aqueous phase; (4) The oil phase and aqueous phase obtained in step (3) are respectively sent into a membrane filter and filtered to obtain a filtrate product containing cyclohexanone oxime.

[0065] The inventive concept of this invention is as follows: First, cyclohexanone, tert-butanol, and ammonia are thoroughly mixed and emulsified using a microchannel mixer to prevent cyclohexanone stratification and reduce the concentration of tert-butanol solvent. Then, they are initially mixed with hydrogen peroxide and pre-reacted to initially reduce the raw material concentration. The resulting pre-reaction liquid undergoes catalytic oxime reaction in the reaction device. The oil phase and aqueous phase obtained by hydrocyclone separation are sent to membrane filters to obtain filtrate containing cyclohexanone oxime. The aqueous phase concentrate containing catalyst obtained by filtration is returned to the pre-mixing and emulsification process, allowing the catalyst to enter the entire reaction system for catalytic reaction. The oil phase concentrate obtained by filtration is returned to the pre-reaction process and reused through filtration. This creates a closed loop for the raw materials and catalyst in the entire reaction system, which not only reduces waste liquid discharge and raw material waste but also reduces shutdown frequency and enhances automation.

[0066] Preferably, in step (1), the amounts of cyclohexanone and tert-butanol are such that the mass concentration of cyclohexanone in the reaction system is 15-40% (more preferably 18-30%), the mass concentration of tert-butanol is 15-40% (more preferably 20-40%), and the mass ratio of tert-butanol to cyclohexanone is 2.0-0.1:1 (more preferably 1.5-0.6:1, and even more preferably 1.5-0.8:1). Limiting the concentrations of cyclohexanone and tert-butanol is to effectively regulate the polarity and solubility of the reaction system, promote sufficient contact between cyclohexanone and ammonia, improve the selectivity and conversion rate of the oxime reaction, and avoid the formation of byproducts. Within this concentration range, the system has good fluidity, which is beneficial to the stable operation of subsequent cyclone separation and membrane filtration, ensuring the efficiency of catalyst recycling and product yield.

[0067] Preferably, in step (1), the mass concentration of ammonia in the ammonia material in the reaction system is 2-9% (more preferably 4-8%). At this ammonia concentration, the ammonia is in excess relative to the theoretical value, with a portion used as a reaction raw material and a portion providing an alkaline environment.

[0068] Preferably, in step (1), the ammonia material includes gaseous ammonia or ammonia water. The mass concentration of the ammonia water is 20-30%.

[0069] Preferably, in step (1), the mixing and emulsification treatment is carried out at a temperature of 50–80°C (more preferably 65–80°C) and a residence time of 0.1–20 s (more preferably 0.5–15 s). Heating is for preheating. If the temperature is too low, the subsequent heating will not reach the reaction temperature; if the temperature is too high, energy will be wasted. The longer the residence time, the larger the mixer volume, increasing equipment costs, and the reaction will be difficult to control. More preferably, hot water or steam at ≥90°C is introduced into the heating jacket of the No. 1 microchannel mixing reactor to preheat to the above temperature.

[0070] Preferably, in step (1), after the cyclohexanone and tert-butanol are dissolved and mixed, they are first fed into a filtration device before being added to the ammonia material, and filtered at 40-80°C (more preferably 50-70°C) to obtain a mixed filtrate. Filtration at this temperature not only removes impurities but also preheats the material. More preferably, hot water or steam at ≥90°C is introduced into the heating jackets of filtration devices 1 and 2 to preheat the material to the above-mentioned temperature.

[0071] Preferably, in step (2), the molar ratio of hydrogen peroxide to cyclohexanone is 1.05–1.18:1 (more preferably 1.05–1.14:1). The selection of the amount of hydrogen peroxide ensures that the mass concentration of hydrogen peroxide before entering the reaction device after mixing and reaction in the microchannel mixing reactor and membrane mixing reactor is 0–1%.

[0072] Preferably, in step (2), the pre-reaction temperature is 70–88°C, and the residence time is 0.1–20 s (more preferably 0.5–15 s). Pre-reaction reacts a portion of the cyclohexanone, reducing the concentration of the cyclohexanone raw material and preventing the precipitation of cyclohexanone oxime and the stratification of cyclohexanone. More preferably, cooling water at ≤25°C is circulated through the cooling jacket of the No. 2 microchannel mixing reactor to maintain the pre-reaction temperature.

[0073] Preferably, in step (2), the hydrogen peroxide is first fed into a filtration device and filtered at 40–80°C (more preferably 50–70°C) before being added to obtain purified hydrogen peroxide. More preferably, the hydrogen peroxide is fed into filter #2, and hot water or steam at ≥90°C is passed through the heating jacket of filter #2 to preheat it to the above temperature. The mass concentration of the added hydrogen peroxide is 25–50%.

[0074] Preferably, in steps (1) and (2), when the pressure drop between the mixing inlet and outlet of the microchannel mixing reactor is >0.5MPa, online ultrasonic cleaning is performed.

[0075] Preferably, in step (2), the pre-reaction liquid is then fed into the membrane mixing reactor, hydrogen peroxide is added, and a preliminary reaction is carried out to obtain the initial reaction liquid.

[0076] Preferably, in step (2), when the initial reaction is increased, the total amount of hydrogen peroxide remains unchanged, and the ratio of hydrogen peroxide used in the pre-reaction to the initial reaction is 10-40:90-60 (more preferably 20-40:80-60). The resulting pre-reaction liquid enters the membrane mixing reactor and mixes with hydrogen peroxide that permeates through the tubular membrane as microdroplets, and the initial reaction occurs immediately. By adding hydrogen peroxide stepwise, continuously, and uniformly, the utilization rate of hydrogen peroxide is greatly improved, avoiding ineffective decomposition of hydrogen peroxide and excessive oxidation to generate by-product impurities due to excessively high local concentrations, thereby improving the selectivity of the reaction. Since the reaction time in the microchannel reaction mixer is relatively short, it then enters the membrane mixing reactor. When the microchannel reaction mixer and the membrane mixing reactor are used in combination, more hydrogen peroxide is allocated to the membrane mixing reactor, which is more conducive to improving the reaction efficiency.

[0077] Preferably, in step (2), the initial reaction temperature is 80–90°C, and the residence time is 0.1–20 s (more preferably 0.5–15 s). Under these reaction conditions, most of the cyclohexanone can be reacted completely. More preferably, cooling water at ≤25°C is circulated into the cooling jacket of the membrane mixing reactor to maintain the initial reaction temperature.

[0078] Preferably, in step (2), when two membrane mixing reactors are used in series for the initial reaction, the obtained pre-reaction liquid is fed into the series-connected membrane mixing reactors, and the mass ratio of hydrogen peroxide added to the series-connected membrane mixing reactors is 1:0.2 to 1.5 (more preferably 1:0.5 to 1.5). The purpose of setting up two-stage membrane mixing reactors is to achieve multi-stage addition of hydrogen peroxide, and the temperature of each stage can be controlled independently, so that hydrogen peroxide can be uniformly added to the reaction raw materials for reaction.

[0079] Preferably, in step (2), when the pressure difference between the inside and outside of the tubular membrane of the membrane mixing reactor is >0.3MPa, online ultrasonic cleaning is performed.

[0080] Preferably, in step (3), the mass concentration of the solid catalyst in the reaction system is 1-10% (more preferably 3-7%). At this catalyst concentration, the reaction can be controlled to achieve a better catalytic effect. If there is too little catalyst, the catalytic effect will be poor; if there is too much catalyst, the cost will increase and the probability of equipment blockage will also increase.

[0081] Preferably, in step (3), the solid-phase catalyst includes silane-modified titanium-silicon molecular sieves, etc. The titanium-silicon molecular sieves achieve surface silanization through silane modification, which improves the dispersion effect of the solid-phase catalyst in the reaction system and avoids catalyst agglomeration.

[0082] Preferably, the average particle size of the silane-modified titanium-silicon molecular sieve is 100 nm to 5 μm (more preferably 100 nm to 2 μm). Using a silane-modified titanium-silicon molecular sieve catalyst with a small particle size allows for better dispersion in low-solvent systems.

[0083] Preferably, in step (3), the oxime reaction temperature is 80–90°C, the pressure is 0.1–0.5 MPa (more preferably 0.1–0.3 MPa), the rotation speed is 40–200 r / min (more preferably 100–150 r / min), and the residence time is 30–80 min (more preferably 50–80 min). If the reaction temperature is too low, the conversion rate will be low; if the reaction temperature is too high, there will be more side reactions and poor selectivity. At the specified residence time, the reaction can proceed more fully, but if the residence time is too long, the product will be less. More preferably, cooling water at ≤25°C is introduced into the cooling jacket of the reaction apparatus to cool down and maintain the oxime reaction temperature.

[0084] Preferably, in step (4), the filtration temperature is 70–90°C and the membrane pressure difference is 0.05–0.15 MPa. Steam is introduced into the heating jacket of the membrane filter for heating to avoid the precipitation of cyclohexanone oxime due to excessively low temperature, which would affect the operation of the filter.

[0085] Preferably, in step (4), when the concentration of cyclohexanone oxime in the liquid phase of the oil phase separation concentrate discharged from the membrane filter is >70%, the amount of tert-butanol is increased. By detecting the concentration of cyclohexanone oxime, it is possible to avoid the precipitation of cyclohexanone oxime due to excessively high concentration, which would cause clogging of the membrane filter.

[0086] Preferably, in step (4), the aqueous phase separation concentrate containing the catalyst obtained by filtration is returned to step (1), and the oil phase separation concentrate obtained by filtration is returned to step (2).

[0087] The beneficial effects of this invention are as follows: (1) The ammonium oxime mixing and reaction system of the present invention has a simple structure, is green and environmentally friendly, safe and reliable. It has verified the "double low" target on an industrially feasible scale for the first time, and provides a new path for the green upgrade of traditional caprolactam devices; (2) The present invention proposes an integrated scheme of "microchannel emulsification + temperature control" for the ammonia oxime mixing and reaction process: using microchannel instantaneous microemulsion technology, complete dissolution of cyclohexanone is achieved under the condition that the mass ratio of tert-butanol / cyclohexanone is ≤2:1, the amount of tert-butanol used is extremely low, and the energy consumption of tert-butanol separation is low; further, an integrated scheme of "microchannel emulsification + multi-site addition of H2O2 + temperature control" is proposed: H2O2 is added through multiple membrane mixers and permeates into the raw material mixture in the form of microdroplets, and then a reaction occurs, reducing the instantaneous concentration peak. In the filtrate product containing cyclohexanone oxime, the mass concentration of hydrogen peroxide is ≤1%, the hydrogen peroxide consumption is reduced by 1.7-7.9%, and the conversion rate of cyclohexanone is ≥99.9%, the selectivity of cyclohexanone oxime is ≥99.9%, the consumption of tert-butanol is reduced by ≥50-75%, and the energy consumption of subsequent solvent recovery is reduced by ≥43-67%. The process boasts high hydrogen peroxide utilization, precise reaction temperature control, excellent raw material mixing, high cyclohexanone conversion rate, high selectivity for cyclohexanone oxime, no other byproducts generated, simple process, low cost, and no scale-up effect. It can be directly coupled with existing caprolactam units, making it suitable for industrial production. Attached Figure Description

[0088] Figure 1 This is a schematic diagram of the overall structure of Example 1 of the ammonium oxime mixing and reaction system of the present invention; Figure 2 This is a schematic diagram of the overall structure of Example 2 of the ammonium oxime mixing and reaction system of the present invention; Figure 3 This is a schematic diagram of the overall structure of the ammonium oxime mixing and reaction system of the present invention, Example 3; Figure 4 This is a schematic diagram of the cross-sectional structure of the membrane filter in Examples 1-3 of the ammonia oxime mixing and reaction system of the present invention (heating jacket omitted). Figure 5This is a schematic diagram of the membrane mixing reactor in Examples 2 and 3 of the ammonia oxime mixing and reaction system of the present invention; Figure 6 yes Figure 5 A schematic diagram of the cross-sectional structure at point AA (the spiral guide vane is omitted). Detailed Implementation

[0089] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0090] The hydrogen peroxide used in the embodiments and comparative examples of this invention has a mass concentration of 50%, and the tert-butanol, cyclohexanone, and ammonia (mass concentration of 25%) are of analytical grade; the average particle size of the silane-modified titanium silicate molecular sieve used is 100 nm; unless otherwise specified, the raw materials or chemical reagents used in the embodiments and comparative examples of this invention are obtained through conventional commercial channels.

[0091] Example 1 of an ammonium oxime mixing and reaction system like Figure 1 , 4 As shown, an ammonia oxime mixing and reaction system includes: 1# and 2# filter devices 1, 1# and 2# microchannel mixing reactors 2, a reaction device 4, and 1# and 2# membrane filters 5. Each of the 1# and 2# filter devices 1 has a feed inlet 1-1 on one side. The outlet 1-2 on the other side of the 1# filter device 1 is connected to the mixing inlet 2-1 of the 1# microchannel mixing reactor 2, and the outlet 2-2 of the 1# microchannel mixing reactor 2 is connected to the mixing inlet 2-1 of the 2# microchannel mixing reactor 2. The outlet 1-2 on the other side of the 2# filter device 1 is connected to the hydrogen peroxide inlet 2-3 of the 2# microchannel mixing reactor 2. The outlet 2-2 of the #2 microchannel mixing reactor 2 is connected to the inlet 4-1 at the top of the reaction device 4; the oil phase outlet 4-2 in the middle of the reaction device 4 is connected to the tube-side inlet 5-1 of the #2 membrane filter 5, and the tube-side outlet 5-2 of the #2 membrane filter 5 is connected to the mixing inlet 2-1 of the #2 microchannel mixing reactor 2; the aqueous phase outlet 4-3 at the bottom of the reaction device 4 is connected to the tube-side inlet 5-1 of the #1 membrane filter 5, and the tube-side outlet 5-2 of the #1 membrane filter 5 is connected to the mixing inlet 2-1 of the #1 microchannel mixing reactor 2; both the #1 and #2 membrane filters 5 are provided with a shell-side outlet 5-3 in the middle.

[0092] In the filter devices 1# and 2#, the layered filter element 6 is composed of a support layer 6-1, a transition layer 6-2, and a precision filter layer 6-3, sequentially from the inlet 1-1 to the outlet 1-2. The precision filter layer 6-3, the transition layer 6-2, and the support layer 6-1 are all ceramic membranes. The precision filter layer 6-3 has a pore size of 0.1μm and a thickness of 0.03mm. The transition layer 6-2 has a pore size of 5.0μm, consists of 3 layers, and each layer has a thickness of 0.3mm. The support layer 6-1 has a pore size of 30μm and a thickness of 1.0mm. The heating jacket 7 of the filter devices 1# and 2# has a heat source inlet 7-1 near the outlet 1-2 and a heat source outlet 7-2 near the inlet 1-1.

[0093] The No. 1 and No. 2 microchannel mixing reactors 2 are both heart-shaped passive chaotic microchannels with a Reynolds number of 1600 and a channel diameter of 2.0 mm. The heating jacket 7 of the No. 1 microchannel mixing reactor 2 has a heat source inlet 7-1 near the discharge port 2-2 and a heat source outlet 7-2 near the mixing inlet 2-1. The cooling jacket 8 of the No. 2 microchannel mixing reactor 2 has a cold water inlet 8-1 near the discharge port 2-2 and a cold water outlet 8-2 near the mixing inlet 2-1. Both the No. 1 and No. 2 microchannel mixing reactors 2 are equipped with ultrasonic devices. A flow regulating valve 9 and a flow meter 10 are sequentially installed between the discharge port 1-2 of the No. 2 filter device 1 and the hydrogen peroxide inlet 2-3 of the No. 2 microchannel mixing reactor 2.

[0094] The reaction device 4 is equipped with a stirring device 4-4 and a cyclone separator 4-5. The stirring blades 4-4-1 of the stirring device 4 are located at 1 / 3 of the height from the bottom of the reaction device 4, and the top of the cyclone separator 4-5 is located at 1 / 4 of the height from the bottom of the reaction device 4 and is slightly lower than the stirring blades 4-4-1. The cooling jacket 8 of the reaction device 4 has a cold water inlet 8-1 on one side of the lower part and a cold water outlet 8-2 on one side of the upper part. The oil phase outlet 4-2 and the water phase outlet 4-3 of the reaction device 4 are respectively connected to the tube inlet 5-1 of the No. 2 and No. 1 membrane filters 5 by circulation pumps 11.

[0095] Among them, the No. 1 and No. 2 membrane filters 5 are tubular filter elements 6 with open ends; the tubular filter element 6 is composed of a precision filtration layer 6-3, a transition layer 6-2, and a support layer 6-1 from the outside to the inside, and the precision filtration layer 6-3, the transition layer 6-2, and the support layer 6-1 are all ceramic membranes; the precision filtration layer 6-3 has a pore size of 0.1μm and a thickness of 0.03mm; the transition layer 6-2 has a pore size of 5.0μm, consists of 5 layers, and each layer has a thickness of 0.2mm; The support layer 6-1 has a pore size of 30μm and a thickness of 1.0mm; the heating jacket 7 of the No. 1 and No. 2 membrane filters 5 has a heat source inlet 7-1 near the tube outlet 5-2 and a heat source outlet 7-2 near the tube inlet 5-1; an online cyclohexanone oxime detector is installed after the tube outlet 5-2 of the No. 2 membrane filter 5; a pressure regulating valve 12 is installed between the tube outlet 5-2 of the No. 1 and No. 2 membrane filters 5 and the mixing inlet 2-2 of the No. 1 and No. 2 microchannel mixing reactor 2.

[0096] Temperature and pressure display instruments are installed on all connecting pipelines.

[0097] The working process of the ammonia oxime mixing and reaction system in this embodiment of the invention is as follows: First, cyclohexanone and tert-butanol are dissolved and mixed, and then fed into filter device 1 (1#) to filter impurities, and then fed into microchannel mixing reactor 2 (1#). Under the preheating of the heat source in heating jacket 7, they are fully mixed and emulsified. The resulting premixed liquid is fed into microchannel mixing reactor 2 (2#). At the same time, hydrogen peroxide filtered by filter device 2 is added through hydrogen peroxide inlet 2-3 of microchannel mixing reactor 2#, and a pre-reaction occurs with the premixed liquid. Cooling jacket 8 cools the exothermic reaction, and the resulting pre-reaction liquid is fed into reaction device 4. During the reaction, the solid catalyst precipitates downward with the aqueous phase in hydrocyclone separator 4-5. The reaction product is separated into oil phase and aqueous phase: the oil phase flows out from the middle of reaction device 4 and is sent to membrane filter 5 (2#) by circulating pump 11. Under the heating of steam in heating jacket 7, it is filtered, containing a large amount of cyclohexanone. The oil phase of cyclohexanone oxime is filtered out from the shell-side outlet 5-3 of membrane filter 5 (No. 2) and sent to the alcohol recovery tower. The intercepted solid catalyst, excess reactants, and products are separated as oil phase concentrate and flow out from the tube-side outlet 5-2 of membrane filter 5 (No. 2) and sent to microchannel mixing reactor 2 (No. 2). The aqueous phase containing solid catalyst flows out from the bottom of the reaction device 4 and is sent to membrane filter 5 (No. 1) by circulating pump 11. Under the heating of steam in the heating jacket 7, the aqueous phase containing a small amount of cyclohexanone oxime is filtered out from the shell-side outlet 5-3 of membrane filter 5 (No. 1) and sent to the alcohol recovery tower. The intercepted solid catalyst and excess reactants are separated as aqueous phase concentrate and flow out from the tube-side outlet 5-2 of membrane filter 5 (No. 1) and sent to microchannel mixing reactor 2 (No. 1). When the system is running stably, solid catalyst is uniformly distributed in microchannel mixing reactors 2 (No. 1) and reaction device 4, enabling efficient mixed catalytic reactions to occur in each part.

[0098] Example 2 of an ammonium oxime mixing and reaction system like Figure 2 , 4 As shown in Figure 6, based on System Embodiment 1, the No. 2 microchannel mixing reactor 2 is replaced with a membrane mixing reactor 3. The membrane mixing reactor 3 has a hydrogen peroxide inlet 3-2-1 located in the middle of the outer side of the shell 3-2. The outlet 2-2 of the No. 1 microchannel mixing reactor 2 is connected to the inlet 3-1-1 of the tube side of the membrane mixing reactor 3. The outlet 1-2 on the other side of the No. 2 filter device 1 is connected to the hydrogen peroxide inlet 3-2-1 located in the middle of the outer side of the shell 3-2 of the membrane mixing reactor 3. The outlet 3-1-2 of the tube side of the membrane mixing reactor 3 is connected to the inlet 4-1 at the top of the reaction device 4. The membrane mixing reactor 3 includes a shell 3-2; a tubular membrane 3-3 is fitted inside the shell 3-2; a shell side 3-4 is formed between the outer side of the tubular membrane 3-3 and the shell 3-2, and a tube side 3-1 is formed inside the tubular membrane 3-3; an SK-type spiral guide vane 3-1-3 is provided inside the tube side 3-1; the beginning and end ends of the shell 3-2 and the tubular membrane 3-3 are sealed by a tube sheet 3-5; the tubular membrane 3-3 has a diameter of 30 mm and a length of 230 mm, and is connected to the shell 3-2. The shells 3-2 are of the same length; the tubular membrane 3-3 is a single-channel ceramic membrane with a pore size of 100 nm; the cooling jacket 8 of the membrane mixing reactor 3 has a cold water inlet 8-1 near the discharge port 3-1-2 and a cold water outlet 8-2 near the feed port 3-1-1; the membrane mixing reactor 3 is equipped with an ultrasonic device; a flow regulating valve 9 and a flow meter 10 are sequentially installed between the discharge port 1-2 of the #2 filter device 1 and the hydrogen peroxide feed port 3-2-1 of the membrane mixing reactor 3. The rest is the same as in System Example 1.

[0099] The working process of the ammonia oxime mixing and reaction system in this embodiment differs from that in System Embodiment 1 only in that: the obtained premixed liquid is fed into the feed port 3-1-1 of the tube side 3-1 of the membrane mixing reactor 3, and hydrogen peroxide is added through the hydrogen peroxide feed port 3-2-1 located in the middle of the outer side of the tube shell 3-2 of the membrane mixing reactor 3. Under pressure, the hydrogen peroxide is cut into microdroplets through the micropore channels of the tubular membrane 3-3 and enters the inner side of the tubular membrane 3-3, where it undergoes a pre-reaction with the premixed liquid. The cooling jacket 8 cools the exothermic reaction, and then the pre-reaction liquid is sent to the reaction device. When the system is running stably, the solid catalyst is uniformly distributed in the #1 microchannel mixing reactor 2, the membrane mixing reactor 3, and the reaction device 4, enabling each part to undergo a highly efficient mixing catalytic reaction. The rest is the same as in System Embodiment 1.

[0100] Example 3 of an ammonium oxime mixing and reaction system like Figures 3-6 As shown, based on system embodiment 1, membrane mixing reactors 1 and 2 are connected in series after the 2# microchannel mixing reactor 2. A hydrogen peroxide inlet 3-2-1 is located in the middle of the outer side of the shell 3-2 of the membrane mixing reactor 3. The outlet 2-2 of the 2# microchannel mixing reactor 2 is connected to the inlet 3-1-1 of the tube side 3-1 of the 1# membrane mixing reactor 3, and the outlet 3-1-2 of the tube side 3-1 of the 1# membrane mixing reactor 3 is connected to the inlet 3-1-1 of the tube side 3-1 of the 2# membrane mixing reactor 3. The outlet 1-2 on the other side of the 2# filter device 1 is connected to the hydrogen peroxide inlet 2-3 of the 2# microchannel mixing reactor 2 and the hydrogen peroxide inlet 3-2-1 located in the middle of the outer side of the shell 3-2 of the 1# and 2# membrane mixing reactors 3. The outlet 3-1-2 of the tube side 3-1 of the 2# membrane mixing reactor 3 is connected to the inlet 4-1 at the top of the reaction device 4. The No. 1 and No. 2 membrane mixing reactors 3 include a shell 3-2; a tubular membrane 3-3 is fitted inside the shell 3-2; a shell side 3-4 is formed between the outer side of the tubular membrane 3-3 and the shell 3-2, and a tube side 3-1 is formed inside the tubular membrane 3-3; an SK-type spiral guide vane 3-1-3 is provided inside the tube side 3-1; the beginning and end ends of the shell 3-2 and the tubular membrane 3-3 are sealed by a tube sheet 3-5; the diameter of the tubular membrane 3-3 is 30 mm and its length is 230 mm, the same as the length of the shell 3-2; The tubular membrane 3-3 is a single-channel ceramic membrane with a pore size of 100 nm; the cooling jacket 8 of the No. 1 and No. 2 membrane mixing reactors 3 has a cold water inlet 8-1 near the discharge port 3-1-2 and a cold water outlet 8-2 near the feed port 3-1-1; both the No. 1 and No. 2 membrane mixing reactors 3 are equipped with ultrasonic devices; a flow regulating valve 9 and a flow meter 10 are sequentially installed between the discharge port 1-2 of the No. 2 filter device 1 and the hydrogen peroxide feed port 3-2-1 of the No. 2 microchannel mixing reactor 2 and the No. 1 and No. 2 membrane mixing reactors 3. The rest is the same as in System Example 1.

[0101] The difference between the working process of the ammonia oxime mixing and reaction system in this embodiment and that in System Embodiment 1 is only that: the obtained pre-reaction liquid is further fed into the feed port 3-1-1 of the tube side 3-1 of the No. 1 membrane mixing reactor 3, while hydrogen peroxide filtered by the No. 2 filter device 2 is added through the hydrogen peroxide feed port 3-2-1 located in the middle of the outer side of the tube shell 3-2 of the No. 1 and No. 2 membrane mixing reactors 3. Under pressure, the hydrogen peroxide is cut into microdroplets through the micropore channels of the tubular membrane 3-3 and enters the inner side of the tubular membrane 3-3, where it undergoes an initial reaction with the pre-reaction liquid inside the tubular membrane 3-3. The cooling jacket 8 cools the exothermic reaction, and then the initial reaction liquid is discharged from the discharge port 3-1-2 of the tube side 3-1 of the No. 2 membrane mixing reactor 3 and sent to the reaction device 4. When the system is running stably, solid-phase catalyst is uniformly distributed in the No. 1 microchannel mixing reactor 2, the No. 1 and No. 2 membrane mixing reactors 3 and the reaction device 4, so that each part can undergo a highly efficient mixed catalytic reaction. Example 1 of the same system.

[0102] Example 1 of an ammonium oxime mixing and reaction process The process in this embodiment is based on Embodiment 1 of the ammonium oxime mixing and reaction system of the present invention.

[0103] (1) After dissolving and mixing cyclohexanone and tert-butanol, it is fed into filter device 1 together with ammonia. The amount of cyclohexanone and tert-butanol is such that the mass concentration of cyclohexanone in the reaction system is 25.4%, the mass concentration of tert-butanol is 24.2%, the mass ratio of tert-butanol to cyclohexanone is 0.95:1, and the mass concentration of ammonia in the reaction system is 7.4%. Hot water at 90°C is introduced into the heating jacket of filter device 1, and the mixture is filtered at 50°C to obtain a mixed filtrate. The obtained mixed filtrate is then sent into microchannel mixing reactor 1. Hot water at 90°C is introduced into the heating jacket of microchannel mixing reactor 1, and the mixture and emulsification are carried out at 75°C for a residence time of 1 second to obtain a premixed liquid. (2) The hydrogen peroxide was fed into the No. 2 filter device. Hot water at 90°C was passed through the heating jacket of the No. 2 filter device and filtered at 50°C to obtain impurity-free hydrogen peroxide. The premixed liquid obtained in step (1) was sent into the No. 2 microchannel mixing reactor, and the obtained impurity-removing hydrogen peroxide was added (the molar ratio of hydrogen peroxide to cyclohexanone was 1.18:1). Cooling water at 25°C was introduced into the cooling jacket of the No. 2 microchannel mixing reactor, and the pre-reaction was carried out at 75°C for 1 second to obtain the pre-reaction liquid. When the pressure drop between the inlet and outlet of the No. 1 and No. 2 microchannel mixing reactors is greater than 0.5 MPa, online ultrasonic cleaning is performed. (3) The pre-reaction liquid obtained in step (2) is sent into the reaction device, and silane-modified titanium silicon molecular sieve is added to make its mass concentration in the reaction system 5%. Cooling water at 25°C is introduced into the cooling jacket of the reaction device, and oxime reaction is carried out at 85°C, 0.2MPa, and 150r / min. The residence time is 70min, and oil phase and water phase are obtained. (4) The oil phase and aqueous phase obtained in step (3) are respectively sent into membrane filters No. 2 and No. 1. Steam is introduced into the heating jacket of membrane filters No. 1 and No. 2. Filtration is carried out at 75°C and membrane pressure difference of 0.1 MPa to obtain filtrate product containing cyclohexanone oxime. When the concentration of cyclohexanone oxime in the liquid phase of the oil phase separation concentrate discharged from the No. 2 membrane filter is >70%, the amount of tert-butanol is increased. The aqueous phase separation concentrate containing catalyst obtained by filtration is returned to step (1), and the oil phase separation concentrate obtained by filtration is returned to step (2).

[0104] Analysis revealed that the filtrate containing cyclohexanone oxime contained 29.29% cyclohexanone oxime by mass, 2.99% ammonia by mass, and no hydrogen peroxide residue. The utilization rate of hydrogen peroxide (conversion rate / water-ketone ratio) was 84.7%, indicating improved utilization. The water content was 42.97%, the tert-butanol concentration was 24.25%, the cyclohexanone concentration was <0.011%, and the amount of tert-butanol used (tert-butanol concentration / cyclohexanone oxime concentration) was <0.9%. The conversion rate of cyclohexanone (= (cash concentration of cyclohexanone feed - residual concentration of cyclohexanone) / cyclohexanone feed concentration) is 99.96% for kg / kg oxime, and the selectivity of cyclohexanone oxime (= (mass concentration of cyclohexanone oxime / 113)*98 / (cash concentration of cyclohexanone feed - residual concentration of cyclohexanone)*100%) is 99.96%. When both selectivity and conversion rate are above 99.9%, it indicates that the product quality is good. At the same time, the consumption of tert-butanol is reduced by ≥50%, and the energy consumption of subsequent solvent recovery is reduced by ≥37.5%, indicating that the reduction in the amount of tert-butanol used saves the steam required for all material recovery, which has exceeded the current industrial level.

[0105] Example 2 of an ammonium oxime mixing and reaction process The process in this embodiment is based on Embodiment 2 of the ammonium oxime mixing and reaction system of the present invention.

[0106] (1) After dissolving and mixing cyclohexanone and tert-butanol, it is fed into filter device 1 together with ammonia. The amount of cyclohexanone and tert-butanol is such that the mass concentration of cyclohexanone in the reaction system is 19.81%, the mass concentration of tert-butanol is 39.69%, the mass ratio of tert-butanol to cyclohexanone is 2:1, and the mass concentration of ammonia in the reaction system is 6.34%. Hot water at 90°C is introduced into the heating jacket of filter device 1, and the mixture is filtered at 55°C to obtain a mixed filtrate. The obtained mixed filtrate is then sent into microchannel mixing reactor 1. Hot water at 90°C is introduced into the heating jacket of microchannel mixing reactor 1, and the mixture and emulsification are carried out at 80°C for a residence time of 1 second to obtain a premixed liquid. When the pressure drop between the inlet and outlet of the No. 1 microchannel mixing reactor is greater than 0.5 MPa, online ultrasonic cleaning is performed. (2) The hydrogen peroxide was fed into the No. 2 filter device. Hot water at 90°C was passed through the heating jacket of the No. 2 filter device. The filter was then filtered at 55°C to obtain impurity-free hydrogen peroxide. The premixed liquid obtained in step (1) is fed into the membrane mixing reactor, and the obtained impurity-removing hydrogen peroxide is added (the molar ratio of hydrogen peroxide to cyclohexanone is 1.08:1). Cooling water at 25°C is introduced into the cooling jacket of the membrane mixing reactor, and the pre-reaction is carried out at 85°C for 5 seconds to obtain the pre-reaction liquid. When the pressure difference between the inside and outside of the tubular membrane in the membrane mixing reactor is >0.3MPa, online ultrasonic cleaning is performed; (3) The pre-reaction liquid obtained in step (2) is sent into the reaction device, and silane-modified titanium silicon molecular sieve is added to make its mass concentration in the reaction system 5%. Cooling water at 25°C is introduced into the cooling jacket of the reaction device, and oxime reaction is carried out at 86°C, 0.22MPa, and 100r / min. The residence time is 75min, and oil phase and water phase are obtained. (4) Same as step (4) in process example 1.

[0107] Testing revealed that the filtrate containing cyclohexanone oxime contained 23.00% cyclohexanone oxime by mass, 2.91% ammonia by mass, no hydrogen peroxide residue, and a hydrogen peroxide utilization rate of 92.6%. The use of a membrane mixing reactor successfully increased the hydrogen peroxide utilization rate to over 90%. The water content was 33.99%, the tert-butanol concentration was 39.70%, the cyclohexanone concentration was <0.01%, the cyclohexanone conversion rate was 99.95%, and the cyclohexanone oxime selectivity was 99.96%. Both selectivity and conversion rates exceeding 99.9% indicate good product quality.

[0108] Example 3 of an ammonium oxime mixing and reaction process The process in this embodiment is based on Embodiment 3 of the ammonium oxime mixing and reaction system of the present invention.

[0109] (1) After dissolving and mixing cyclohexanone and tert-butanol, it is fed into filter device 1 together with ammonia. The amount of cyclohexanone and tert-butanol is such that the mass concentration of cyclohexanone in the reaction system is 26.13%, the mass concentration of tert-butanol is 24.58%, the mass ratio of tert-butanol to cyclohexanone is 0.94:1, and the mass concentration of ammonia in the reaction system is 7.51%. Hot water at 90°C is introduced into the heating jacket of filter device 1, and the mixture is filtered at 50°C to obtain a mixed filtrate. The mixed filtrate is then sent into microchannel mixing reactor 1. Hot water at 90°C is introduced into the heating jacket of microchannel mixing reactor 1, and the mixture and emulsification are carried out at 75°C for a residence time of 1 second to obtain a premixed liquid. (2) The hydrogen peroxide was fed into the No. 2 filter device. Hot water at 90°C was passed through the heating jacket of the No. 2 filter device and filtered at 50°C to obtain impurity-free hydrogen peroxide. The premixed liquid obtained in step (1) was sent into the No. 2 microchannel mixing reactor, and impurity-removing hydrogen peroxide equivalent to 35% of the total amount of hydrogen peroxide was added (the molar ratio of the total amount of hydrogen peroxide to cyclohexanone was 1.05:1). Cooling water at 25°C was introduced into the cooling jacket of the No. 2 microchannel mixing reactor, and the pre-reaction was carried out at 80°C for 1 second to obtain the pre-reaction liquid. The obtained pre-reaction liquid was sent into the No. 1 and No. 2 membrane mixing reactors connected in series. 35% and 30% of the total amount of hydrogen peroxide were added respectively to remove impurities. Cooling water at 25°C was circulated into the cooling jackets of the No. 1 and No. 2 membrane mixing reactors. The initial reaction was carried out at 85°C. The residence time of the No. 1 and No. 2 membrane mixing reactors was 5s. The initial reaction liquid was obtained. When the pressure drop between the inlet and outlet of the No. 1 and No. 2 microchannel mixing reactors is greater than 0.5 MPa, online ultrasonic cleaning is performed. When the pressure difference between the inside and outside of the tubular membrane of membrane mixing reactors #1 and #2 is greater than 0.3 MPa, online ultrasonic cleaning is performed. (3) The initial reaction solution obtained in step (2) is sent into the reaction device, and silane-modified titanium silicon molecular sieve is added to make its mass concentration in the reaction system 5%. Cooling water at 25°C is introduced into the cooling jacket of the reaction device, and oxime reaction is carried out at 85°C, 0.2MPa, and 100r / min. The residence time is 70min, and oil phase and water phase are obtained. (4) Same as step (4) in process example 1.

[0110] Testing revealed that the filtrate containing cyclohexanone oxime contained 30.27% cyclohexanone oxime by mass, 2.96% ammonia by mass, no hydrogen peroxide residue, a hydrogen peroxide utilization rate of 95.2%, a water mass fraction of 42.19%, a tert-butanol mass concentration of 24.58%, a cyclohexanone mass concentration <0.014%, a tert-butanol dosage <0.9 kg / kg oxime, a cyclohexanone conversion rate of 99.95%, and a cyclohexanone oxime selectivity of 99.96%. A selectivity and conversion rate both above 99.9% indicate good product quality. Furthermore, the consumption of tert-butanol decreased by ≥50%, and the energy consumption for subsequent solvent recovery decreased by ≥37.5%. This demonstrates that the combined use of a microchannel mixing reactor and a membrane mixing reactor can increase the multiphase mixing effect and hydrogen peroxide utilization rate, thereby reducing the dosage of tert-butanol and hydrogen peroxide and saving steam required for all material recovery, exceeding current industrial standards.

[0111] Example 4 of an ammonium oxime mixing and reaction process The process in this embodiment is based on Embodiment 3 of the ammonium oxime mixing and reaction system of the present invention.

[0112] The difference between this embodiment and process embodiment 3 is only that: in step (1), hot water at 90°C is introduced into the heating jacket of filter device 1#, and the mixture is filtered at 60°C to obtain a mixed filtrate; the obtained mixed filtrate is then sent to microchannel mixing reactor 1#, and hot water at 90°C is introduced into the heating jacket of microchannel mixing reactor 1#, and the mixture and emulsification are carried out at 80°C with a residence time of 1s to obtain a premixed liquid; in step (2), impurity-removing hydrogen peroxide equivalent to 30% of the total amount of hydrogen peroxide is added; the obtained pre-reaction liquid is sent to membrane mixing reactors 1# and 2# connected in series, and impurity-removing hydrogen peroxide equivalent to 30% and 40% of the total amount of hydrogen peroxide is added respectively; the initial reaction is carried out at 80°C, and the residence time of membrane mixing reactors 1# and 2# is 5s; the rest is the same as process embodiment 3.

[0113] Testing revealed that the filtrate containing cyclohexanone oxime contained 30.26% cyclohexanone oxime by mass, 2.95% ammonia by mass, no hydrogen peroxide residue, a hydrogen peroxide utilization rate of 95.2%, a water mass fraction of 42.20%, a tert-butanol mass concentration of 24.59%, a cyclohexanone mass concentration <0.019%, a tert-butanol dosage <0.9 kg / kg oxime, a cyclohexanone conversion rate of 99.93%, and a cyclohexanone oxime selectivity of 99.95%. A selectivity and conversion rate both above 99.9% indicate good product quality. Furthermore, the consumption of tert-butanol decreased by ≥50%, and the energy consumption for subsequent solvent recovery decreased by ≥37.5%. This demonstrates that the combined use of a microchannel mixing reactor and a membrane mixing reactor can increase the multiphase mixing effect and hydrogen peroxide utilization rate, thereby reducing the dosage of tert-butanol and hydrogen peroxide and saving steam required for all material recovery, exceeding current industrial standards.

[0114] Comparative Examples 1-1 to 1-4 The only difference between this comparative example and process example 1 is that the #2 microchannel reactor is removed, and the #1 microchannel reactor is directly connected to the inlet of the reaction device. Everything else is the same as in system example 2.

[0115] (1) Cyclohexanone and tert-butanol were dissolved and mixed, and then fed into filter device #1 along with ammonia. The amounts of cyclohexanone and tert-butanol were adjusted such that in the reaction systems of Comparative Examples 1-1 to 1-4, the mass concentrations of cyclohexanone were 26.13%, 19.95%, 25.4%, and 19.54%, respectively; the mass concentrations of tert-butanol were 24.58%, 39.97%, 24.2%, and 39.15%, respectively; the mass ratios of tert-butanol to cyclohexanone were 0.94:1, 2.0:1, 0.95:1, and 2.0:1, respectively; and the mass concentrations of ammonia in the reaction system were 7.51%, 6.39%, and 7.4%, respectively. 6.26%, hot water at 90℃ was introduced into the heating jacket of filter device #1, and the mixture was filtered at 50℃ to obtain a mixed filtrate; the mixed filtrate was then sent into microchannel mixing reactor #1, and hot water at 90℃ was introduced into the heating jacket of microchannel mixing reactor #1, and the mixture and emulsification were carried out at 75℃ with a residence time of 1s to obtain a premixed liquid; (2) The hydrogen peroxide was fed into the No. 2 filter device. Hot water at 90°C was passed through the heating jacket of the No. 2 filter device and filtered at 50°C to obtain impurity-free hydrogen peroxide. (3) The premixed solution obtained in step (1) and the hydrogen peroxide obtained in step (2) (in the reaction systems of comparative examples 1-1 to 1-4, the molar ratio of hydrogen peroxide to cyclohexanone is 1.05:1, 1.05:1, 1.2:1, and 1.2:1, respectively) are simultaneously fed into the reaction apparatus. Silane-modified titanium-silicon molecular sieve is added to make its mass concentration in the reaction system 5%. Cooling water at 25°C is introduced into the cooling jacket of the reaction apparatus. The oxime reaction is carried out at 85°C, 0.2MPa, and a rotation speed of 150r / min for a residence time of 70min. (4) The product and catalyst obtained in step (3) are pumped into the inner side of the membrane filter through a circulating pump. By adjusting the pressure regulating valve, some of the product passes through the membrane wall to the outside of the membrane, and the catalyst particles and the remaining product are returned to the reaction device.

[0116] Analysis of the filtrate products containing cyclohexanone oxime obtained from Comparative Examples 1-1 and 1-2 revealed the following concentrations: cyclohexanone oxime mass concentrations were 20.13%, 17.80%, 23.64%, and 22.51%, respectively; ammonia mass concentrations were 3.31%, 3.15%, 3.24%, and 3.23%, respectively; hydrogen peroxide utilization rates were 67.1%, 73.8%, 70.4%, and 83.3%, respectively; water mass fractions were 39.56%, 34.44%, 41.54%, and 34.89%, respectively; and tert-butanol mass concentrations were 24.66%, 39.97%, 24.29%, and 39.24%, respectively. The mass concentrations of cyclohexanone were 7.73%, 4.5%, 3.95%, and 0.01%, respectively, and the dosages of tert-butanol were 1.23, 2.25, 1.03, and 1.74 kg / kg oxime, respectively. The conversion rates of cyclohexanone were 70.42%, 77.44%, 84.45%, and 99.95%, respectively, and the selectivity of cyclohexanone oxime was 94.88%, 99.92%, 95.58%, and 99.96%, respectively. This indicates that without using a microchannel mixing reactor and / or a membrane mixing reactor, to simultaneously achieve high conversion rates of cyclohexanone and high selectivity of cyclohexanone oxime, a large amount of tert-butanol solvent and hydrogen peroxide are required, resulting in high raw material costs.

[0117] Comparative Example 2: An ammoniation mixing and reaction process This comparative process is based on Example 2 of the ammonium oxime mixing and reaction system of the present invention.

[0118] The only difference between this comparative example and process example 2 is that in step (1), steam is introduced into the heating jacket of filter device #1, and the mixture is filtered at 90°C to obtain a mixed filtrate; the obtained mixed filtrate is then sent to microchannel mixing reactor #1, and steam is introduced into the heating jacket of microchannel mixing reactor #1, and the mixture and emulsification are carried out at 90°C for a residence time of 1s to obtain a premixed liquid; in step (2), hydrogen peroxide is sent to filter device #2, and steam is introduced into the heating jacket of filter device #2, and the mixture is filtered at 90°C to obtain impurity-removed hydrogen peroxide; the premixed liquid obtained in step (1) is sent to membrane mixing reactor, and the pre-reaction is carried out at 95°C for a residence time of 5s. The rest is the same as process example 2.

[0119] The test results showed that the filtrate containing cyclohexanone oxime had a cyclohexanone oxime concentration of 20.18%, an ammonia concentration of 2.91%, no hydrogen peroxide residue, a hydrogen peroxide utilization rate of 92.6%, a water mass fraction of 33.94%, a tert-butanol mass concentration of 39.68%, a cyclohexanone mass concentration of <0.01%, a tert-butanol dosage of up to 1.97 kg / kg oxime, a cyclohexanone conversion rate of 99.97%, and a cyclohexanone oxime selectivity of only 88.39%. This indicates that when the reaction temperature in steps (1) and (2) is too high, the probability of side reactions increases, and the increase in byproducts leads to a serious decrease in selectivity.

[0120] Comparative Example 3: An ammonium oxime mixing and reaction process This comparative process is based on Example 3 of the ammoniation mixing and reaction system of the present invention.

[0121] The only difference between this comparative example and process example 3 is that in step (3), 25°C cooling water is introduced into the cooling jacket of the reaction device, and the oxime reaction is carried out at 70°C, 0.15MPa, and a rotation speed of 100r / min, with a residence time of 70min. The rest is the same as process example 3.

[0122] Analysis revealed that the filtrate containing cyclohexanone oxime contained 28.32% cyclohexanone oxime by mass, 2.96% ammonia by mass, no hydrogen peroxide residue (hydrogen peroxide utilization rate was only 88.6%), 41.59% water by mass, 24.58% tert-butanol by mass, and 1.81% cyclohexanone by mass. The amount of tert-butanol used was less than 0.9 kg / kg oxime, resulting in a cyclohexanone conversion rate of only 93.07% and a selectivity of 99.96%. This indicates that a decrease in the oximation temperature in the reaction apparatus leads to a decrease in the cyclohexanone conversion rate.

Claims

1. An ammonoxime mixing and reaction system, characterized in that: Option 1: Includes microchannel mixing reactors #1 and #2, a reaction apparatus, and membrane filters #1 and #2; the outlet of microchannel mixing reactor #1 is connected to the mixing inlet of microchannel mixing reactor #2, and the outlet of microchannel mixing reactor #2 is connected to the inlet at the top of the reaction apparatus; the oil phase outlet in the middle of the reaction apparatus is connected to the tube-side inlet of membrane filter #2, and the tube-side outlet of membrane filter #2 is connected to the mixing inlet of microchannel mixing reactor #2; the aqueous phase outlet at the bottom of the reaction apparatus is connected to the tube-side inlet of membrane filter #1, and the tube-side outlet of membrane filter #1 is connected to the mixing inlet of microchannel mixing reactor #1; hydrogen peroxide inlet is provided on microchannel mixing reactor #2; both membrane filters #1 and #2 have shell-side outlets in their middle sections. Option 2: Based on Option 1, replace the No. 2 microchannel mixing reactor with a membrane mixing reactor. The membrane mixing reactor has a hydrogen peroxide inlet in the middle of the outer side of the shell. The outlet of the No. 1 microchannel mixing reactor is connected to the tube-side inlet of the membrane mixing reactor, and the tube-side outlet of the membrane mixing reactor is connected to the inlet at the top of the reaction device. Option 3: Based on Option 1, a membrane mixing reactor is connected in series after the No. 2 microchannel mixing reactor. The membrane mixing reactor has a hydrogen peroxide inlet in the middle of the outer side of the shell. The outlet of the No. 2 microchannel mixing reactor is connected to the inlet of the membrane mixing reactor, and the outlet of the membrane mixing reactor is connected to the inlet at the top of the reaction device.

2. The ammonium oxime mixing and reaction system according to claim 1, characterized in that: The microchannel mixing reactor includes passive chaotic microchannels; the Reynolds number of the passive chaotic microchannels is 100–2500, and the channel diameter is 0.5–5.0 mm; the passive chaotic microchannels include T-shaped, Y-shaped, heart-shaped, serpentine, herringbone, or spiral channels; the heating jacket of the No. 1 microchannel mixing reactor has a heat source inlet near the discharge port and a heat source outlet near the mixing inlet; one or more No. 1 microchannel mixing reactors can be connected in series or parallel; the cooling jacket of the No. 2 microchannel mixing reactor has a cold water inlet near the discharge port and a cold water outlet near the mixing inlet. The reactor is equipped with a cold water outlet; an ultrasonic device is installed on the microchannel mixing reactor; a stirring device and a cyclone separator are installed inside the reactor; the stirring blades of the stirring device are located at 1 / 3 to 1 / 2 of the height from the bottom of the reactor, and the top of the cyclone separator is located at 1 / 4 to 1 / 3 of the height from the bottom of the reactor and slightly lower than the stirring blades; a cold water inlet is located on one side of the lower part of the cooling jacket of the reactor, and a cold water outlet is located on one side of the upper part; circulation pumps are respectively installed between the oil phase outlet and the water phase outlet of the reactor and the tube inlet of the membrane filter; the membrane filter is a tubular filter element with open ends; The tubular filter element consists of a precision filter layer, a transition layer, and a support layer, arranged sequentially from the outside to the inside. The precision filter layer, transition layer, and support layer can be ceramic membranes, metal membranes, or organic membranes. The pore size of the precision filter layer, transition layer, and support layer gradually increases. The pore size of the precision filter layer is 0.05–10.00 μm. The thickness of the precision filter layer (when it is a ceramic membrane) is 0.01–0.05 mm. The thickness of the precision filter layer (when it is a metal membrane) is 0.1–0.5 mm. The pore size of the transition layer is 1–10 μm. The number of transition layers is 1–8. When the transition layer is a ceramic membrane… The thickness of each layer is 0.1–0.5 mm; when the transition layer is a metal membrane, the thickness of each layer is 0.3–0.8 mm; the pore size of the support layer is 10–50 μm; the thickness of the support layer when it is a ceramic membrane or a metal membrane is 0.5–1.2 mm; the heating jackets of the No. 1 and No. 2 membrane filters have a heat source inlet near the tube outlet and a heat source outlet near the tube inlet; an online cyclohexanone oxime detector is installed after the tube outlet of the No. 2 membrane filter; a pressure regulating valve is installed between the tube outlet of the No. 1 and No. 2 membrane filters and the mixing inlet of the No. 1 and No. 2 microchannel mixing reactors.

3. The ammonium oxime mixing and reaction system according to claim 1 or 2, characterized in that: The membrane mixing reactor may be one or more connected in series; the membrane mixing reactor includes a shell; a tubular membrane is sleeved inside the shell; the outer side of the tubular membrane and the shell form a shell side, and the inner side of the tubular membrane is a tube side; a spiral guide vane is provided inside the tube side; the beginning and end of the shell and the tubular membrane are sealed by a tube sheet; the spiral guide vane includes segmented and recombined guide vanes; the segmented and recombined guide vanes include SV, SK, SX, SH, or SL type guide vanes; the diameter of the tubular membrane is 2–100 mm, and the length is 30–50 mm. 00mm, the same length as the tube shell; the tubular membrane includes single-channel or multi-channel microporous membranes; the pore size of the microporous membrane is 10nm~100μm; the microporous membrane includes one or more composite membranes selected from metal membranes, ceramic membranes, or organic membranes; the cooling jacket of the membrane mixing reactor has a cold water inlet near the discharge port and a cold water outlet near the feed port; the membrane mixing reactor is equipped with an ultrasonic device; a No. 1 filter device is also provided before the No. 1 microchannel mixing reactor, and in the No. 2 microchannel mixing reactor and / or membrane mixing... A No. 2 filtration device is also provided before the reactor; both No. 1 and No. 2 filtration devices have inlets on one side; the outlet of the No. 1 filtration device is connected to the mixing inlet of the No. 1 microchannel mixing reactor, and the outlet of the No. 2 filtration device is connected to the hydrogen peroxide inlet of the No. 2 microchannel mixing reactor and / or the hydrogen peroxide inlet of one or more membrane mixing reactors located in the middle of the outer shell; the layered filter element in the filtration device consists of a support layer, a transition layer and a precision filter layer from the inlet to the outlet; in the filtration device, the precision filter layer, the transition layer and the support layer are all ceramic membranes or organic membranes; the relevant properties of the precision filter layer, the transition layer and the support layer in the filtration device are the same as those of the membrane filter; a flow regulating valve and a flow meter are sequentially provided between the outlet of the No. 2 filtration device and the hydrogen peroxide inlet of the No. 2 microchannel mixing reactor or the membrane mixing reactor; the heating jacket of the filtration device has a heat source inlet near the outlet and a heat source outlet near the inlet; temperature and pressure display instruments are provided on all connecting pipelines.

4. A process for ammonium oxime mixing and reaction in the system described in any one of claims 1 to 3, characterized in that, Includes the following steps: (1) After dissolving and mixing cyclohexanone and tert-butanol, it is fed into the No. 1 microchannel mixing reactor along with ammonia material for mixing and emulsification to obtain a premixed solution; (2) The premixed liquid obtained in step (1) is sent into the No. 2 microchannel mixing reactor or membrane mixing reactor, hydrogen peroxide is added, and pre-reaction is carried out to obtain the pre-reaction liquid; (3) The pre-reaction liquid obtained in step (2) is sent into the reaction device, a solid catalyst is added, and an oxime reaction is carried out to obtain an oil phase and an aqueous phase; (4) The oil phase and aqueous phase obtained in step (3) are respectively sent into a membrane filter and filtered to obtain a filtrate product containing cyclohexanone oxime.

5. The ammonium oxime mixing and reaction process according to claim 4, characterized in that: In step (1), the amounts of cyclohexanone and tert-butanol are such that the mass concentration of cyclohexanone in the reaction system is 15-40%, the mass concentration of tert-butanol is 15-40%, and the mass ratio of tert-butanol to cyclohexanone is 2.0-0.1:1; the mass concentration of ammonia in the ammonia material in the reaction system is 2-9%; the ammonia material includes gaseous ammonia or ammonia water; the temperature of the mixing and emulsification treatment is 50-80℃, and the residence time is 0.1-20s; after the cyclohexanone and tert-butanol are dissolved and mixed, they are first sent to a filtration device before being added to the ammonia material, and filtered at 40-80℃ to obtain a mixed filtrate.

6. The ammonium oxime mixing and reaction process according to claim 4 or 5, characterized in that: In step (2), the molar ratio of hydrogen peroxide to cyclohexanone is 1.05 to 1.18:1; the temperature of the pre-reaction is 70 to 88°C, and the residence time is 0.1 to 20 seconds; before adding the hydrogen peroxide, it is first sent to a filtration device and filtered at 40 to 80°C to obtain impurity-free hydrogen peroxide; in steps (1) and (2), when the pressure drop between the mixing inlet and outlet of the microchannel mixing reactor is >0.5 MPa, online ultrasonic cleaning is performed.

7. The ammonium oxime mixing and reaction process according to any one of claims 4 to 6, characterized in that: In step (2), the pre-reaction liquid is then fed into the membrane mixing reactor, hydrogen peroxide is added, and a preliminary reaction is carried out to obtain the preliminary reaction liquid. When the preliminary reaction is increased, the total amount of hydrogen peroxide remains unchanged, and the ratio of hydrogen peroxide used in the pre-reaction to the preliminary reaction is 10-40:90-60. The temperature of the preliminary reaction is 80-90℃, and the residence time is 0.1-20s. When the preliminary reaction uses two membrane mixing reactors in series, the obtained pre-reaction liquid is fed into the membrane mixing reactors in series, and the mass ratio of hydrogen peroxide added to the membrane mixing reactors in series is 1:0.2-1.

5. When the pressure difference between the inside and outside of the tubular membrane of the membrane mixing reactor is >0.3MPa, online ultrasonic cleaning is performed.

8. The ammonium oxime mixing and reaction process according to any one of claims 4 to 7, characterized in that: In step (3), the mass concentration of the solid catalyst in the reaction system is 1-10%; the solid catalyst includes silane-modified titanium-silicon molecular sieve; the average particle size of the silane-modified titanium-silicon molecular sieve is 100nm-5μm; the temperature of the oxime reaction is 80-90℃, the pressure is 0.1-0.5MPa, the rotation speed is 40-200r / min, and the residence time is 30-80min.

9. The ammonium oxime mixing and reaction process according to any one of claims 4 to 8, characterized in that: In step (4), the filtration temperature is 70-90℃ and the membrane pressure difference is 0.05-0.15MPa; when the concentration of cyclohexanone oxime in the liquid phase of the oil phase separation concentrate discharged from the membrane filter is >70%, the amount of tert-butanol is increased; the aqueous phase separation concentrate containing the catalyst obtained by filtration is returned to step (1), and the oil phase separation concentrate obtained by filtration is returned to step (2).

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