Cyclohexanone oxime preparation device
By designing a solvent-free cyclohexanone oxime preparation device, and using a catalyst separator and membrane filter for efficient separation of catalyst and product, the problems of high energy consumption and easy catalyst deactivation in cyclohexanone oxime production were solved, and the low-energy production of high-purity cyclohexanone oxime was realized.
Patent Information
- Application Number
- CN202520064210.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-10
- Publication Date
- 2026-02-10
- Estimated Expiration
- 2035-01-10
AI Technical Summary
Existing cyclohexanone oxime production facilities suffer from high energy consumption, short catalyst lifespan, and poor product quality.
A device for preparing cyclohexanone oxime is designed, including a reaction unit, a water washing unit, a product separation unit, and an extraction unit. It adopts a solvent-free ammonoximation reaction and achieves efficient separation of catalyst and product through a catalyst separator and a membrane filter, thereby reducing energy consumption and extending catalyst life.
This method extends catalyst lifespan, improves product purity, reduces energy consumption, and enables efficient cyclohexanone oxime production without the addition of organic solvents.
Smart Images
Figure CN223887985U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the production device field of organic chemical raw materials, concretely relates to a cyclohexanone oxime preparation device. BACKGROUND
[0002] Cyclohexanone oxime, as a very key organic intermediate in chemical industry, its importance mainly reflects in being used for producing caprolactam, and caprolactam is the key raw material for manufacturing polyamide-6 (nylon-6) fiber and engineering plastic. Nylon-6 has been widely applied in many fields such as tire cord, rope manufacturing, mechanical part production and clothing fabric because of its good wear resistance, mechanical property and chemical stability. With the continuous prosperity of these downstream industries, the market demand of caprolactam is rising, and then more urgent requirements are put forward for the preparation technology of cyclohexanone oxime.
[0003] The traditional cyclohexanone oxime production method mainly adopts hydroxylamine method, which takes cyclohexanone and hydroxylamine salt (such as hydroxylamine sulfate) as raw materials and carries out reaction under acidic conditions. However, a large amount of ammonium sulfate by-product is generated in the reaction process, which not only leads to low atomic utilization rate of raw materials, but also has high subsequent treatment cost of ammonium sulfate, and its emission may also cause negative impact on the environment, in addition, the acidic reaction condition puts high requirements on the material of the reaction equipment, and special materials resistant to acid corrosion must be used, which increases the investment cost and subsequent maintenance cost of the equipment.
[0004] In view of the many problems existing in the traditional process, the preparation technology of cyclohexanone oxime under the concept of green chemistry has become a research hotspot. In recent years, the new cyclohexanone oximation process without tert-butyl alcohol solvent has become the focus of research, aiming at breaking through the technical bottleneck of traditional solvent system in energy consumption, environmental protection and other aspects, but the existing cyclohexanone oxime preparation device and process without tert-butyl alcohol solvent have many deficiencies.
[0005] The solvent-free preparation device and method disclosed in CN116651013A mixes cyclohexanone, gaseous ammonia and hydrogen peroxide first and then reacts in a reaction kettle, and then realizes the production of cyclohexanone oxime through steps such as extraction, flashing and refining. However, the stability of the catalyst is poor, and the catalyst is easy to be deactivated, and the impurities in cyclohexanone oxime are not effectively separated, and the energy consumption is high.
[0006] Therefore, it is urgent to develop a new device for completing the cyclohexanone oximation reaction without adding solvent. UTILITY MODEL CONTENT
[0007] The purpose of this invention is to overcome the problems of high energy consumption, short catalyst lifespan, and poor product quality in existing cyclohexanone oxime production devices, and to provide a cyclohexanone oxime preparation device. The cyclohexanone oxime preparation device provided by this invention features a catalyst with good stability and low deactivation, low energy consumption, and achieves efficient separation of the catalyst and product, resulting in a high-purity cyclohexanone oxime product.
[0008] To achieve the above objectives, this utility model provides a cyclohexanone oxime preparation apparatus, which includes: a reaction unit, a water washing unit 6, a product separation unit 7 and an extraction unit 8. The reaction unit includes at least one reactor 1, a reaction heat exchanger 2, a catalyst separator 3 and a membrane filter 4 disposed inside or downstream of the catalyst separator 3.
[0009] The reactor 1 is provided with a raw material inlet connected to the circulating catalyst slurry pipeline 10 and a hydrogen peroxide inlet connected to the hydrogen peroxide supply device. The circulating catalyst slurry pipeline 10 is provided with a cyclohexanone inlet and an ammonia inlet.
[0010] Reactor 1, reaction heat exchanger 2 and catalyst separator 3 are connected in sequence by pipelines. A circulating organic solvent inlet is provided on the pipeline between reactor 1 and reaction heat exchanger 2, or a circulating organic solvent inlet is provided on the pipeline between reaction heat exchanger 2 and catalyst separator 3.
[0011] Catalyst separator 3 is used to separate the reaction slurry from reactor 1 and the mixed extract material of organic solvent into two phases;
[0012] The organic phase outlet of catalyst separator 3, water washing unit 6 and product separation unit 7 are connected in sequence; the organic phase outlet of product separation unit 7 is connected to the organic solvent inlet of extraction unit 8.
[0013] Through the above technical solution, this utility model has the following beneficial effects:
[0014] The cyclohexanone oxime preparation apparatus provided by this utility model is suitable for ammoxime reactions and the separation of reaction products without the addition of additional organic solvents in the ammoxime reaction stage. It greatly extends the service life of the catalyst, has good operational stability, and a simple process. While maintaining a high conversion rate of cyclohexanone and selectivity of the product cyclohexanone oxime, it effectively reduces the consumption of catalyst, effectively removes impurities from cyclohexanone oxime, and produces a high-quality cyclohexanone oxime product. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of a system for preparing cyclohexanone oxime according to a specific embodiment of the present invention.
[0016] Explanation of reference numerals in the attached figures
[0017] Detailed Implementation
[0018] The endpoints and any values of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of the various ranges, the endpoint values of the various ranges and individual point values, and individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.
[0019] In this invention, unless otherwise stated, directional terms such as "up," "down," "left," and "right" generally refer to the orientation shown in the accompanying drawings. "Inner" and "outer" refer to the inner and outer sides relative to the outline of each component itself.
[0020] This utility model provides a cyclohexanone oxime preparation apparatus, which includes: a reaction unit, a water washing unit 6, a product separation unit 7 and an extraction unit 8. The reaction unit includes at least one reactor 1, a reaction heat exchanger 2, a catalyst separator 3 and a membrane filter 4 disposed inside or downstream of the catalyst separator 3.
[0021] The reactor 1 is provided with a raw material inlet connected to the circulating catalyst slurry pipeline 10 and a hydrogen peroxide inlet connected to the hydrogen peroxide supply device. The circulating catalyst slurry pipeline 10 is provided with a cyclohexanone inlet and an ammonia inlet.
[0022] Reactor 1, reaction heat exchanger 2 and catalyst separator 3 are connected in sequence by pipelines. A circulating organic solvent inlet is provided on the pipeline between reactor 1 and reaction heat exchanger 2, or a circulating organic solvent inlet is provided on the pipeline between reaction heat exchanger 2 and catalyst separator 3.
[0023] Catalyst separator 3 is used to separate the reaction slurry from reactor 1 and the mixed extract material of organic solvent into two phases;
[0024] The organic phase outlet of catalyst separator 3, water washing unit 6 and product separation unit 7 are connected in sequence; the organic phase outlet of product separation unit 7 is connected to the organic solvent inlet of extraction unit 8.
[0025] The cyclohexanone oxime preparation apparatus provided by this utility model is suitable for ammoxime reactions and the separation of reaction products without the addition of additional organic solvents in the ammoxime reaction stage. It greatly extends the service life of the catalyst, has good operational stability, and a simple process. While maintaining a high conversion rate of cyclohexanone and selectivity of the product cyclohexanone oxime, it effectively reduces the consumption of catalyst, effectively removes impurities from cyclohexanone oxime, and produces a high-quality cyclohexanone oxime product.
[0026] According to this utility model, preferably, the device further includes a cyclohexanone supply device and an ammonia supply device.
[0027] According to this utility model, preferably, the cyclohexanone supply device and the ammonia supply device are respectively connected to the cyclohexanone inlet and the ammonia inlet provided on the circulating catalyst slurry pipeline 10 through the cyclohexanone feed pipeline and the ammonia feed pipeline, respectively, for supplying the reactor 1 with a mixture of cyclohexanone, ammonia and circulating catalyst slurry; the hydrogen peroxide supply device is connected to the hydrogen peroxide inlet provided on the reactor 1 through the hydrogen peroxide feed pipeline, for supplying the reactor 1 with hydrogen peroxide.
[0028] According to this invention, there is no particular limitation on the specific types of cyclohexanone supply device, ammonia supply device, and hydrogen peroxide supply device, as long as they can provide cyclohexanone, ammonia, and hydrogen peroxide. Conventional cyclohexanone supply devices, ammonia supply devices, and hydrogen peroxide supply devices in the art can all be used in this invention, such as storage tanks or pipelines.
[0029] According to a preferred embodiment of the present invention, the organic phase outlet of the water washing unit 6 is connected to the inlet of the product separation unit 7, and the first clear liquid outlet of the water washing unit 6 is connected to the aqueous phase inlet of the extraction unit 8.
[0030] The turbid liquid outlet of the membrane filter 4 is connected to the reactor 1 through the circulating catalyst slurry pipeline 10, and the second clear liquid outlet of the membrane filter 4 is connected to the aqueous phase inlet of the extraction unit 8.
[0031] The organic solvent outlet of the extraction unit 8 is connected to the pipeline between the reactor 1 and the reaction heat exchanger 2 via the circulating organic solvent pipeline 11, or to the pipeline between the reaction heat exchanger 2 and the catalyst separator 3.
[0032] According to this utility model, it should be noted that the organic solvent from the extraction unit 8 and the reaction slurry from the reactor 1 are extracted during the mixing process in the pipeline. Cyclohexanone oxime is extracted into the organic solvent as the organic phase, and the catalyst enters the aqueous phase to obtain the mixed extracted material, which then enters the reaction heat exchanger 2 or the catalyst separator 3.
[0033] According to a preferred embodiment of the present invention, the catalyst separator 3 includes a vessel body and a stirrer, an inner extension tube, and an inner sleeve disposed within the vessel body; the bottom end of the stirrer is disposed near the bottom of the vessel body; the inner extension tube is disposed at the top of the vessel body, with its inlet end located outside the vessel body and its outlet end located inside the vessel body, the outlet end of the inner extension tube being higher than the bottom end of the stirrer; the inner sleeve is fitted inside the inner extension tube, the outlet end of the inner sleeve being higher than the outlet end of the inner extension tube; a gas phase balance port is provided on the side wall of the inner extension tube, the gas phase balance port being higher than the outlet end of the inner sleeve.
[0034] According to this utility model, the catalyst separator can achieve the natural separation of the organic phase containing cyclohexanone oxime and the aqueous phase containing catalyst. By setting a stirrer near the bottom of the catalyst separator (in the aqueous phase section), the catalyst is prevented from depositing at the bottom of the separator, ensuring the continuous separation of the two phases and improving the separation efficiency. The combination of the inner tube and the inner sleeve reduces the amount of catalyst carried in the organic phase, ensuring the separation effect.
[0035] According to this utility model, preferably, the inlet end of the inner sleeve is flush with the inlet end of the inner extension tube, and the annular space region formed by the inlet end of the inner sleeve and the inlet end of the inner extension tube is closed.
[0036] According to this invention, preferably, the length ratio of the inner sleeve to the inner extension tube is 5-30:1, more preferably 8-25:1. By optimizing the lengths of the inner extension tube and the inner sleeve, the loss of catalyst entrainment in the organic phase product can be reduced.
[0037] According to this invention, preferably, the ratio of the length of the inner tube extending below the upper tangent of the reactor body to the vertical distance between the upper and lower tangents of the reactor body is 0.3-0.95:1, more preferably 0.4-0.9:1. By optimizing the position of the inner tube in the reactor body, the entrainment of the catalyst organic phase can be effectively suppressed.
[0038] According to this utility model, it should be noted that the upper tangent of the vessel body refers to the tangential section at the junction of the upper end cap and the cylinder wall; the lower tangent of the vessel body refers to the tangential section at the junction of the lower end cap and the cylinder wall. In this utility model, the portion of the inner tube outside the vessel body has no effect on the separation effect of the catalyst separator.
[0039] According to this utility model, preferably, the bottom end of the stirrer is provided with a stirring paddle.
[0040] According to this invention, the specific type of the agitator is not particularly limited. Preferably, the agitator is selected from at least one of a propeller agitator, a turbine agitator, an anchor agitator, and a frame agitator.
[0041] According to this utility model, preferably, the number of layers of the stirring paddle is 1-3.
[0042] According to this invention, preferably, the reactor body is further provided with an anti-impact baffle, which is located near the outlet end of the inner tube. The anti-impact baffle effectively buffers the material to be treated containing the catalyst, preventing interface fluctuations caused by liquid impact.
[0043] According to this utility model, preferably, an overflow weir is provided on the upper part of the vessel body, and the overflow weir is located close to the upper part of the vessel body.
[0044] According to this utility model, the shape of the overflow weir is not particularly limited. In a preferred case, the overflow weir is an L-shaped plate, and preferably one end of the L-shaped plate is connected to the inner wall of the vessel.
[0045] According to this utility model, preferably, the upper part of the vessel body is provided with an organic phase outlet, and the organic phase outlet is connected to the overflow weir.
[0046] According to this utility model, preferably, the top of the vessel is provided with a gas phase outlet.
[0047] According to this utility model, preferably, the gas phase balance port is directly connected to the gas phase space at the top of the vessel body, or the gas phase balance port is connected to the gas phase space at the top of the vessel body.
[0048] According to this utility model, preferably, the shape of the lower end cap of the vessel body is at least one of ellipse, sphere and cone, preferably cone.
[0049] According to this utility model, preferably, the vessel body wall and / or the lower end cap side wall are provided with baffles.
[0050] According to this utility model, preferably, the bottom of the vessel is provided with an aqueous phase outlet and an optional turbid liquid outlet.
[0051] According to this utility model, when the membrane filter 4 is installed inside the catalyst separator 3, the aqueous phase containing the catalyst obtained from the phase separation enters the membrane filter 4 for membrane filtration, and the second clear liquid and the circulating catalyst slurry obtained from the membrane filtration are discharged from the aqueous phase outlet and the turbid liquid outlet of the catalyst separator 4, respectively; when the membrane filter 4 is installed downstream of the catalyst separator 3, the aqueous phase containing the catalyst obtained from the phase separation is discharged from the aqueous phase outlet of the catalyst separator 3 and sent into the membrane filter 4 for membrane filtration through a pipeline.
[0052] According to a preferred embodiment of the present invention, the membrane filter 4 includes at least one membrane module. When the membrane filter 4 includes two or more membrane modules, the membrane modules can be connected in parallel and / or in series.
[0053] According to a preferred embodiment of the present invention, the membrane filter 4 is disposed inside the catalyst separator 3, and each membrane module includes a membrane tube and a manifold; or, the membrane filter 4 is disposed at the connection with the aqueous phase outlet of the catalyst separator 3, and each membrane module includes a shell, a tube sheet, a head and a membrane tube, the membrane tube is placed inside the shell, and tube sheets are provided at both ends of the membrane tube for separating the materials on the inner and outer sides of the membrane tube.
[0054] According to this utility model, preferably, the membrane filter 4 is disposed inside the catalyst separator 3, below the anti-surge baffle, with one end of the membrane filter 4 closed and the other end connected to the collecting pipe. The advantage of this preferred embodiment is that the membrane filter is submerged in the aqueous phase, preventing the organic phase from entering the clear aqueous solution through the membrane filter.
[0055] According to this utility model, preferably, when the membrane filter 4 is installed inside the catalyst separator 3, the aqueous phase containing the catalyst permeates from the outer surface of the membrane tube to the inner side of the membrane tube to obtain a second clear liquid, which is collected by the collecting pipe and discharged from the aqueous phase outlet of the catalyst separator 3 through the clear liquid discharge pipeline B. The resulting circulating catalyst slurry (catalyst-rich stream) is discharged from the turbid liquid outlet of the catalyst separator 3.
[0056] According to this utility model, preferably, when the membrane filter 4 is located downstream of the catalyst separator 3, the aqueous phase containing the catalyst enters the membrane filter 4, and the circulating catalyst slurry (catalyst-rich stream) is obtained by flowing through the center of the membrane tube. The second clear liquid is obtained by permeating into the membrane module housing from the inside of the membrane tube. The second clear liquid enters the clear liquid outlet pipeline A on the housing side and is discharged from the membrane filter 4 through the second clear liquid outlet of the membrane filter.
[0057] According to this invention, preferably, both the clear liquid discharge line A and the clear liquid discharge line B are equipped with backwashing lines for backwashing the membrane tubes. In this invention, the medium for the backwashing operation is preferably a second clear liquid and / or water, with the second clear liquid being more preferred.
[0058] This invention does not impose any particular limitations on the type and material of the membrane tube. Those skilled in the art can select it according to actual needs, as long as it can achieve aqueous phase permeation while the catalyst is retained. Preferably, the material of the membrane tube is selected from at least one of ceramics, metals, and high-density polyethylene, preferably ceramics and / or metals, and more preferably metals.
[0059] According to some preferred embodiments of the present invention, in the membrane filter 4, the filtration accuracy of the membrane tube is 0.01-50μm, preferably 0.05-10μm.
[0060] According to this invention, reactor 1 is used to contact a mixture of cyclohexanone, ammonia, and circulating catalyst slurry from circulating catalyst line 10 with hydrogen peroxide from hydrogen peroxide feed line to carry out an ammonium oxime reaction. This invention allows for a wide range of choices regarding the number of reactors in the reaction unit; those skilled in the art can set one or more reactors according to actual needs, and two or more reactors are preferably connected in series.
[0061] According to a preferred embodiment of the present invention, the reaction unit includes 1-4 reactors, preferably 1-2.
[0062] According to a preferred embodiment of the present invention, when the reaction unit contains two or more reactors, each reactor is independently connected to the hydrogen peroxide feed line, so that hydrogen peroxide is fed into multiple reactors simultaneously.
[0063] According to a preferred embodiment of the present invention, a hydrogen peroxide feed distributor is provided in the reactor 1, and the hydrogen peroxide feed distributor is selected from a ring pipe type, a branch pipe type, or a nozzle type.
[0064] According to this invention, preferably, hydrogen peroxide from the hydrogen peroxide feed line is fed into the vicinity of the agitator at the bottom of the reactor via a hydrogen peroxide feed distributor.
[0065] This invention does not impose any particular limitation on the structure of the reactor; conventional reactors in the art can be used, such as a batch reactor.
[0066] According to a preferred embodiment of the present invention, each reactor in the reaction unit is provided with a stirring paddle for stirring and mixing the materials in the reactor.
[0067] This invention does not impose any particular limitation on the type of stirring paddle, as long as it can achieve the above-mentioned functions. For example, the stirring paddle can be selected from at least one of paddle-type, propeller-type, and turbine-type.
[0068] This invention does not have a particular limitation on the number of stirring paddles, but preferably, the number of stirring paddle layers is 1-3 layers.
[0069] According to a preferred embodiment of the present invention, each reactor 1 in the reaction unit is provided with a baffle to prevent the liquid from forming a vortex flow.
[0070] This invention does not have a particular limitation on the number of baffles, but preferably, the number of baffles is 2-6.
[0071] According to a preferred embodiment of the present invention, a reactor may be optionally installed on the circulating catalyst slurry pipeline 10 between the membrane filter 4 and the reactor 1. The "optional" aspect of the present invention means that a heat exchanger may or may not be installed on the circulating catalyst slurry pipeline 10.
[0072] According to a preferred embodiment of this invention, the device further includes a tail gas absorption unit 5. The gas phase inlet of the tail gas absorption unit 5 is connected to the gas phase outlet of the reactor 1, and is used to contact the gas generated by the ammonia oxime reaction with demineralized water to remove ammonia, thereby obtaining demineralized water with absorbed ammonia and reaction tail gas. The reaction tail gas of this invention enters the next process for further treatment.
[0073] According to a preferred embodiment of the present invention, the liquid phase outlet of the tail gas absorption unit 5 is connected to the reactor 1, and is used to send the demineralized water that has absorbed ammonia into the reactor 1.
[0074] According to a preferred embodiment of the present invention, the device further includes an ammonia removal unit 9, the inlet of which is connected to the aqueous phase outlet of the extraction unit 8, for separating wastewater and ammonia water in the aqueous phase discharged from the extraction.
[0075] According to a preferred embodiment of the present invention, the circulating catalyst slurry pipeline 10 is further provided with a circulating ammonia water inlet, and the ammonia water outlet of the deammoniation unit 9 is connected to the circulating ammonia water inlet on the circulating catalyst slurry pipeline 10 for returning ammonia water to the reactor 1. According to the present invention, the wastewater from the deammoniation unit 9 is then fed into the next process for treatment.
[0076] According to the present invention, the extraction unit 8 includes at least one extraction tower for extracting the first clear liquid from the water washing unit 6 and / or the second clear liquid from the membrane filter 4 with organic solvent from the product separation unit 7, and then sending the obtained organic phase to the reaction heat exchanger 2 or the catalyst separator 3 after mixing and extraction with the reaction slurry from the reactor 1 through the circulating organic solvent pipeline 11.
[0077] According to this utility model, preferably, the water washing unit 6 is further provided with a desalinated water inlet for contacting the organic phase from the catalyst separator 3 with the desalinated water for water washing.
[0078] According to some specific embodiments of this utility model, such as Figure 1As shown, the above-mentioned cyclohexanone oxime preparation device is used for ammonium oximation reaction. The circulating catalyst slurry pipeline 10 and the hydrogen peroxide feed pipeline are connected to the reactor 1, respectively. The circulating catalyst slurry pipeline 10 is equipped with a cyclohexanone inlet and an ammonia inlet to supply the reactor 1 with a mixture of cyclohexanone, ammonia, and circulating catalyst slurry and hydrogen peroxide. The ammonium oximation reaction is carried out under stirring conditions to obtain a reaction slurry. The reaction slurry is discharged through the outlet of the reactor 1 and mixed with an organic solvent from the circulating organic slurry pipeline 11. The resulting mixed extract enters the reaction heat exchanger 2 for heat extraction, and then enters the catalyst separator 3 for two-phase separation, which separates the organic phase containing cyclohexanone oxime and the aqueous phase containing the catalyst.
[0079] The aqueous phase section of the catalyst separator 3 is equipped with a stirrer for stirring the aqueous phase containing the catalyst; the gas phase generated from the ammonia oximation reaction enters the tail gas absorption unit 5 through the gas phase outlet of the reactor 1, and removes ammonia by contacting the demineralized water. The ammonia-absorbing demineralized water is then sent back to the reactor 1, and the tail gas enters the next process through the gas phase outlet of the tail gas absorption unit 5.
[0080] The organic phase containing cyclohexanone oxime enters the water washing unit 6 through the organic phase outlet of the catalyst separator 3 for washing, and is divided into an organic phase rich in cyclohexanone oxime and a first clear liquid. The first clear liquid enters the extraction unit 8 through the aqueous phase outlet of the water washing unit. The organic phase rich in cyclohexanone oxime enters the product separation unit 7 through the organic phase outlet of the water washing unit for separation, and is divided into an organic solvent and a cyclohexanone oxime product. The organic solvent enters the extraction unit 8 through the organic solvent outlet of the product separation unit 7. The cyclohexanone oxime product enters the next process.
[0081] The aqueous phase containing the catalyst enters the membrane filter 4 through the aqueous phase outlet of the catalyst separator 3 for membrane filtration, and is divided into circulating catalyst slurry and second clear liquid. The circulating catalyst slurry is returned to the reactor 1 through the turbid liquid outlet of the membrane filter 4 and the circulating catalyst slurry pipeline 10. The second clear liquid enters the extraction unit 8 through the second clear liquid outlet of the membrane filter 4. The organic solvent from the product separation unit 7 extracts the first clear liquid and / or the second clear liquid, and is divided into an organic phase and an aqueous phase.
[0082] The organic phase from extraction unit 8 is mixed with the reaction slurry through the organic phase outlet of extraction unit and the circulating organic solvent pipeline 11. The aqueous phase from extraction unit 8 enters the deammoniation unit 9 through the aqueous phase outlet of extraction unit 8 for deammoniation, and is divided into ammonia water and wastewater. The ammonia water is discharged from the outlet of deammoniation unit 9 and enters the circulating catalyst slurry pipeline 10 through the circulating ammonia water inlet provided on the circulating catalyst slurry pipeline 10. The wastewater is then sent to the next process.
[0083] The present invention will be described in detail below through embodiments. Unless otherwise specified, all raw materials used in the following embodiments and comparative examples are commercially available.
[0084]
[0085]
[0086]
[0087] in, w % represents the mass percentage of the corresponding component in the organic phase from the catalyst separator; 0.867 represents the molecular weight ratio of cyclohexanone to cyclohexanone oxime. m (Catalyst) refers to the total amount of catalyst added, in grams; F (Ketone) represents the cyclohexanone feed rate, kg / h; t The unit operating time is in hours (h). When calculating catalyst consumption, the ketone conversion rate and oxime selectivity are the algebraic averages of the initial and final conversion rates and selectivities.
[0088] Example 1
[0089] Cyclohexanone and ammonia are introduced into the circulating catalyst slurry pipeline through the cyclohexanone and ammonia inlets. A mixture of cyclohexanone, ammonia, and circulating catalyst slurry is fed into the reactor through the circulating catalyst slurry pipeline. Hydrogen peroxide is fed into the vicinity of the agitator at the bottom of the reactor through the hydrogen peroxide feed pipeline and feed distributor. The reaction is carried out at a temperature of 90℃ and a pressure of 0.4 MPaG. The effective volume of the reactor is 3.0L. The reactor contains TS-1 titanium-silicon molecular sieve catalyst, and the mass fraction of the catalyst in the circulating catalyst slurry is 2.5%. The cyclohexanone flow rate is 353 g / h, and the ammonia feed rate is... The flow rate of hydrogen peroxide (35 wt%) was 67 g / h, the flow rate of hydrogen peroxide (35 wt%) was 402 g / h, and the feed rate of the circulating catalyst slurry was 6250 g / h, wherein the mass fraction of cyclohexanone oxime in the circulating catalyst slurry was 1.5%, and the molar ratio of hydrogen peroxide to cyclohexanone in the reaction system was 1.15:1. The resulting reaction slurry overflowed from the reactor outlet and was mixed and extracted with toluene from the circulating organic solvent pipeline. The resulting mixed extract was cooled to 70°C by the reaction heat exchanger and then sent to the catalyst separator. The toluene flow rate was 810 g / h, and the mass ratio of toluene to cyclohexanone oxime in the reaction slurry was 2:1.
[0090] The aqueous phase separated by the catalyst separator is sent to a membrane filter (the membrane filter is equipped with a 10mm diameter, 200mm long sintered metal membrane tube with a filtration accuracy of 0.2μm). The catalyst-rich stream flowing out from the center of the membrane tube is circulated back to the reactor. The second clear liquid, which permeates into the shell from the inside of the membrane tube, is sent to the extraction tower via the clear liquid discharge line. The clear liquid discharge line is equipped with a backwashing line, and the backwashing medium is the second clear liquid. The organic phase separated by the catalyst separator is sent to a water washing tank. The organic phase after water washing in the water washing tank is sent to the toluene oxime separation process. In the toluene oxime separation process, the water-washed organic phase is separated by a distillation column. Cyclohexanone oxime product is obtained from the bottom of the column, and the toluene obtained from the top of the column is sent to the extraction tower.
[0091] The gas phase obtained from the reaction is sent to the tail gas absorption process. In the absorption tower, demineralized water is used to absorb ammonia in the tail gas in a countercurrent manner. The amount of demineralized water added is 71 g / h, the operating pressure is atmospheric pressure, and the absorption liquid is sent to the reaction vessel.
[0092] The wash water (first clear liquid) from the washing tank is mixed with the second clear liquid from the membrane filter and sent to the extraction process. In the extraction tower, toluene from the toluene oxime separation unit is used to countercurrently extract cyclohexanone oxime from the water (first and second clear liquids), where water is the continuous phase and toluene is the dispersed phase. The toluene phase obtained by extraction is mixed with the reaction slurry through the circulating organic solvent pipeline and then sent to the reaction heat exchanger. The aqueous phase obtained by extraction is sent to the deammoniation tower for deammoniation. The operating pressure is atmospheric pressure. The ammonia water obtained at the top of the tower enters the circulating catalyst slurry pipeline through the circulating ammonia water inlet and is circulated back to the reactor. The wastewater obtained from the reactor is discharged.
[0093] The reactor is equipped with baffles and a stirrer, the stirrer being a propeller-type stirrer with a stirring speed of 600 rpm;
[0094] The catalyst separator includes a vessel body and a stirrer, an inner extension tube, and an inner sleeve disposed within the vessel body. The top end of the inner extension tube is located outside the vessel body, and the bottom end of the inner extension tube is located inside the vessel body. The ratio of the length of the inner extension tube extending below the upper tangent of the vessel body to the vertical distance between the tangent and the lower tangent of the vessel body is 0.85:1. The inner sleeve is fitted inside the inner extension tube, and the top end of the inner sleeve is flush with the top end of the inner extension tube. The top of the annular space formed by the inner sleeve and the inner extension tube... The vessel is enclosed, with the length ratio of the inner extension tube to the inner sleeve being 15:1. A gas phase balance port is provided on the side wall of the inner extension tube, which is connected to the gas phase space of the vessel body to ensure gas phase balance. The stirring paddle of the stirrer is located in the water phase section of the vessel body, and the stirring paddle has one layer. An anti-impact baffle is provided at the bottom end of the inner extension tube. The vessel body is also provided with an overflow weir (L-shaped plate, one end of which is connected to the inner wall of the vessel body) and an organic phase outlet connected to the overflow weir. A gas phase outlet is provided at the top of the vessel body.
[0095] The operating conditions inside the catalyst separator are: temperature 69℃, pressure 0.4MPaG; the agitator is an anchor agitator with a rotation speed of 180rpm.
[0096] Under the above process conditions, sampling began after 10 hours of operation (the conversion rate and selectivity at this time were the initial conversion rate and selectivity). Afterwards, samples were taken from the organic phase output of the catalyst separator and the cyclohexanone oxime product for analysis every 10 hours. When the cyclohexanone conversion rate decreased to below 99.6%, the feeding of cyclohexanone, ammonia, and hydrogen peroxide was stopped. The conversion rate, selectivity, and purity of the cyclohexanone oxime product at this point were the final conversion rate, final selectivity, and purity of the cyclohexanone oxime product (Table 1). The unit operating time was recorded, and catalyst consumption was calculated. Gas chromatography was used for analysis. The conversion rate, selectivity, catalyst consumption, cyclohexanone oxime product purity, and unit operating time data are shown in Table 1.
[0097] Example 2
[0098] Cyclohexanone and ammonia are introduced into the circulating catalyst slurry pipeline through the cyclohexanone and ammonia inlets. A mixture of cyclohexanone, ammonia, and circulating catalyst slurry is fed into the reactor through the circulating catalyst slurry pipeline. Hydrogen peroxide is fed into the vicinity of the agitator at the bottom of the reactor through the hydrogen peroxide feed pipeline and feed distributor. The reaction is carried out at a temperature of 90℃ and a pressure of 0.4 MPaG. The effective volume of the reactor is 3.0L. The reactor contains TS-1 titanium-silicon molecular sieve catalyst, and the mass fraction of the catalyst in the circulating catalyst slurry is 2.5%. The cyclohexanone flow rate is 353 g / h, and the ammonia feed rate is... The flow rate of hydrogen peroxide (35 wt%) was 67 g / h, the flow rate of hydrogen peroxide (35 wt%) was 402 g / h, and the feed rate of the circulating catalyst slurry was 6250 g / h, wherein the mass fraction of cyclohexanone oxime in the circulating catalyst slurry was 1.5%, and the molar ratio of hydrogen peroxide to cyclohexanone in the reaction system was 1.15:1. The resulting reaction slurry overflowed from the reactor outlet and was mixed and extracted with toluene from the circulating organic solvent pipeline. The resulting mixed extract was cooled to 70°C by the reaction heat exchanger and then sent to the catalyst separator. The toluene flow rate was 810 g / h, and the mass ratio of toluene to cyclohexanone oxime in the reaction slurry was 2:1.
[0099] The catalyst separator is the same as the catalyst separator in Example 1, except that a membrane filter is installed in the water phase space below the height of the anti-surge baffle of the catalyst separator.
[0100] The aqueous phase obtained from the two-phase separation in the catalyst separator enters the aqueous phase space below the height of the anti-surge baffle of the catalyst separator. A membrane filter (the membrane filter is a sintered metal membrane tube with a diameter of 10 mm and a length of 100 mm, and a filtration accuracy of 0.2 μm) is installed in this space. One end of the membrane tube is closed, and the other end is connected to a collecting pipe, which is connected to the outlet of the second clear liquid. The liquid in the aqueous phase permeates from the outer surface of the membrane filter (membrane tube) to the inner surface of the membrane filter (membrane tube) to obtain the second clear liquid. The second clear liquid is collected by the collecting pipe and then sent to the extraction tower. A backwashing line is installed on the clear liquid outlet line, and the backwashing medium is the second clear liquid. The catalyst-rich stream after filtration by the membrane filter is recycled back to the reactor. The organic phase obtained from the two-phase separation in the catalyst separator is sent to a water washing tank. The organic phase after water washing in the water washing tank is sent to the toluene oxime separation process. In the toluene oxime separation process, the organic phase after water washing is separated by a distillation column. Cyclohexanone oxime product is obtained at the bottom of the column, and the toluene obtained at the top of the column is sent to the extraction tower.
[0101] The gas phase obtained from the reaction is sent to the tail gas absorption process. In the absorption tower, demineralized water is used to absorb ammonia in the tail gas in a countercurrent manner. The amount of demineralized water added is 71 g / h, the operating pressure is atmospheric pressure, and the absorption liquid is sent to the reaction vessel.
[0102] The wash water (first clear liquid) from the washing tank is mixed with the second clear liquid from the membrane filter and sent to the extraction process. In the extraction tower, toluene from the toluene oxime separation unit is used to countercurrently extract cyclohexanone oxime from the water (first and second clear liquids), where water is the continuous phase and toluene is the dispersed phase. The toluene phase obtained by extraction is mixed with the reaction slurry through the circulating organic solvent pipeline and then sent to the reaction heat exchanger. The aqueous phase obtained by extraction is sent to the deammoniation tower for deammoniation. The operating pressure is atmospheric pressure. The ammonia water obtained at the top of the tower enters the circulating catalyst slurry pipeline through the circulating ammonia water inlet and is circulated back to the reactor. The wastewater obtained from the reactor is discharged.
[0103] The reactor is equipped with baffles and a stirrer, which is a propeller-type stirrer with a stirring speed of 600 rpm.
[0104] The operating conditions inside the catalyst separator are: temperature 69℃, pressure 0.4MPaG; the agitator is an anchor agitator with a rotation speed of 180rpm.
[0105] Under the above process conditions, sampling began after 10 hours of operation (the conversion rate and selectivity at this time were the initial conversion rate and selectivity). Afterwards, samples were taken from the organic phase output of the catalyst separator and the cyclohexanone oxime product for analysis every 10 hours. When the cyclohexanone conversion rate decreased to below 99.6%, the feeding of cyclohexanone, ammonia, and hydrogen peroxide was stopped. The conversion rate, selectivity, and purity of the cyclohexanone oxime product at this point were the final conversion rate, final selectivity, and purity of the cyclohexanone oxime product (Table 1). The unit operating time was recorded, and catalyst consumption was calculated. Gas chromatography was used for analysis. The conversion rate, selectivity, catalyst consumption, cyclohexanone oxime product purity, and unit operating time data are shown in Table 1.
[0106] Comparative Example 1
[0107] The method described in Example 1 is different except that a mixture of hydrogen peroxide, cyclohexanone, ammonia, and circulating catalyst slurry is fed into the reactor; the circulating catalyst slurry volume is 2700 g / h.
[0108] Under the above process conditions, sampling began after 10 hours of operation (the conversion rate and selectivity at this time were the initial conversion rate and selectivity). Afterwards, samples were taken from the organic phase output of the catalyst separator and the cyclohexanone oxime product for analysis every 10 hours. When the cyclohexanone conversion rate decreased to below 99.6%, the feeding of cyclohexanone, ammonia, and hydrogen peroxide was stopped. The conversion rate, selectivity, and purity of the cyclohexanone oxime product at this point were the final conversion rate, final selectivity, and purity of the cyclohexanone oxime product (Table 1). The unit operating time was recorded, and catalyst consumption was calculated. Gas chromatography was used for analysis. The conversion rate, selectivity, catalyst consumption, cyclohexanone oxime product purity, and unit operating time data are shown in Table 1.
[0109] Table 1
[0110]
[0111] The results from the examples and comparative examples show that, compared with the comparative examples, the cyclohexanone oxime preparation apparatus provided by the present invention has good catalyst stability and is not easily deactivated during the ammonoximation reaction, effectively reducing catalyst consumption, and has good operating stability. It effectively removes impurities from cyclohexanone oxime, achieves efficient separation of catalyst and product, has high cyclohexanone conversion rate and cyclohexanone oxime selectivity, and has high purity of cyclohexanone oxime product.
[0112] The preferred embodiments of this utility model have been described in detail above; however, this utility model is not limited thereto. Within the scope of the technical concept of this utility model, various simple modifications can be made to the technical solution of this utility model, including combining the various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed by this utility model and are all within the protection scope of this utility model.
Claims
1. An apparatus for preparing cyclohexanone oxime, characterized in that, The device includes: a reaction unit, a water washing unit (6), a product separation unit (7) and an extraction unit (8). The reaction unit includes at least one reactor (1), a reaction heat exchanger (2), a catalyst separator (3) and a membrane filter (4) disposed inside or downstream of the catalyst separator (3). The reactor (1) is provided with a raw material inlet connected to the circulating catalyst slurry pipeline (10) and a hydrogen peroxide inlet connected to the hydrogen peroxide supply device. The circulating catalyst slurry pipeline (10) is provided with a cyclohexanone inlet and an ammonia inlet. The reactor (1), the reaction heat exchanger (2) and the catalyst separator (3) are connected in sequence by pipelines. A circulating organic solvent inlet is provided on the pipeline between the reactor (1) and the reaction heat exchanger (2), or a circulating organic solvent inlet is provided on the pipeline between the reaction heat exchanger (2) and the catalyst separator (3). The catalyst separator (3) is used to separate the reaction slurry from the reactor (1) from the mixed extract of organic solvents into two phases; The organic phase outlet of the catalyst separator (3), the water washing unit (6), and the product separation unit (7) are connected in sequence; the organic phase outlet of the product separation unit (7) is connected to the organic solvent inlet of the extraction unit (8).
2. The apparatus according to claim 1, characterized in that, The organic phase outlet of the water washing unit (6) is connected to the inlet of the product separation unit (7), and the first clear liquid outlet of the water washing unit (6) is connected to the aqueous phase inlet of the extraction unit (8). The turbid liquid outlet of the membrane filter (4) is connected to the reactor (1) through the circulating catalyst slurry pipeline (10), and the second clear liquid outlet of the membrane filter (4) is connected to the aqueous phase inlet of the extraction unit (8). The organic solvent outlet of the extraction unit (8) is connected to the pipeline between the reactor (1) and the reaction heat exchanger (2) via the circulating organic solvent pipeline (11), or to the pipeline between the reaction heat exchanger (2) and the catalyst separator (3).
3. The apparatus according to claim 1, characterized in that, The catalyst separator (3) includes a vessel body and a stirrer, an inner extension tube, and an inner sleeve disposed in the vessel body; the bottom end of the stirrer is disposed near the bottom of the vessel body; the inner extension tube is disposed at the top of the vessel body, the inlet end of the inner extension tube is located outside the vessel body, the outlet end of the inner extension tube is located inside the vessel body, and the outlet end of the inner extension tube is higher than the bottom end of the stirrer; the inner sleeve is sleeved inside the inner extension tube, and the outlet end of the inner sleeve is higher than the outlet end of the inner extension tube; a gas phase balance port is opened on the side wall of the inner extension tube, and the gas phase balance port is higher than the outlet end of the inner sleeve.
4. The apparatus according to claim 3, characterized in that, The inlet end of the inner sleeve is flush with the inlet end of the inner extension tube, and the annular space area formed by the inlet end of the inner sleeve and the inlet end of the inner extension tube is closed. The length ratio of the inner sleeve to the inner extension tube is 5-30:1; The ratio of the length of the inner tube extending below the upper tangent of the vessel body to the vertical distance between the upper and lower tangents of the vessel body is 0.3-0.95:1; The vessel body is also equipped with an anti-impact baffle, which is located near the outlet end of the inner tube.
5. The apparatus according to claim 1 or 2, characterized in that, The reaction unit includes 1-4 reactors (1), each reactor (1) being independently connected to the hydrogen peroxide feed line; The reactor (1) is equipped with a hydrogen peroxide feed distributor, which is selected from loop type, branch type or nozzle type.
6. The apparatus according to claim 1 or 2, characterized in that, In the reaction unit, each reactor (1) is provided with a stirring paddle, which is selected from at least one of paddle type, propeller type, and turbine type, and the number of stirring paddle layers is 1-3 layers; In the reaction unit, each reactor (1) is equipped with a baffle, and the number of baffles is 2-6.
7. The apparatus according to claim 1 or 2, characterized in that, The membrane filter (4) is disposed inside the catalyst separator (3), and each membrane module includes a membrane tube and a manifold; or, The membrane filter (4) is connected to the aqueous phase outlet of the catalyst separator (3), and each membrane module includes a housing, a tube sheet, a head, and a membrane tube; The membrane tube is made of at least one of ceramic, metal and high-density polyethylene, and the filtration accuracy of the membrane tube is 0.01-50μm.
8. The apparatus according to claim 1 or 2, characterized in that, A heat exchanger may be optionally installed on the circulating catalyst slurry pipeline (10) located between the membrane filter (4) and the reactor (1).
9. The apparatus according to claim 1 or 2, characterized in that, The device also includes an ammonia removal unit (9), the inlet of which is connected to the aqueous phase outlet of the extraction unit (8) for separating wastewater and ammonia in the aqueous phase; The circulating catalyst slurry pipeline (10) is also provided with a circulating ammonia water inlet. The ammonia water outlet of the deammoniation unit (9) is connected to the circulating catalyst slurry pipeline (10) and the circulating ammonia water inlet on the circulating catalyst slurry pipeline (10) to return ammonia water to the reactor (1).
10. The apparatus according to claim 1 or 2, characterized in that, The device also includes a tail gas absorption unit (5), the gas phase inlet of which is connected to the gas phase outlet of the reactor (1), for contacting the gas generated by the reaction with the demineralized water to remove ammonia; The liquid phase outlet of the tail gas absorption unit (5) is connected to the reactor (1) to send the demineralized water that has absorbed ammonia into the reactor (1).