59 results about "Cyclohexanone oxime" patented technology

The invention discloses a copper-based catalyst for catalyzing partial hydrogenation of nitrocyclohexane to prepare cyclohexanone-oxime as well as a preparation method and application of the copper-based catalyst. The catalyst comprises a main active component and an auxiliary active component, the main active component is copper, the auxiliary active component is selected from one or more of titanium, vanadium, chromium, molybdenum, zirconium, cadmium, indium, tin, antimony, niobium, silver, iron, zinc, magnesium, aluminum, bismuth, manganese, lanthanum, gold or lead, the total molar ratio of the copper to the auxiliary active component is (100-1): 1, and the catalyst is prepared by adopting a coprecipitation method or a supported impregnation-coprecipitation method. And the process is simple and green. Under mild conditions, the catalyst can realize the conversion rate gt of nitrocyclohexane; the selectivity of cyclohexanone-oxime is greater than or equal to 99%, and the method is obviously superior to the existing non-noble metal system, and is low in cost, good in stability and suitable for industrial production of green synthesis of caprolactam.

This invention relates to the field of cyclohexanone ammoniation to produce cyclohexanone oxime, and discloses a method and system for cyclohexanone ammoniation to produce cyclohexanone oxime. The method includes: mixing cyclohexanone, ammonia, and a circulating catalyst slurry, and then reacting the mixture with hydrogen peroxide to obtain a reaction slurry containing cyclohexanone oxime, ammonia, water, and a catalyst; wherein the feed cyclohexanone accounts for 2-6% of the total mass of cyclohexanone and the circulating catalyst slurry; mixing a portion of the reaction slurry with an organic solvent and then separating the two phases to obtain an organic phase containing cyclohexanone oxime and the organic solvent, and an aqueous phase containing the catalyst; wherein the mass ratio of the organic solvent to the cyclohexanone oxime in this portion of the reaction slurry is 0.5-5:1; reheating the remaining portion of the reaction slurry and recycling it to the reaction; and membrane filtering the aqueous phase containing the catalyst to obtain a clear liquid and a catalyst-rich stream. This method improves the selectivity of cyclohexanone oxime while effectively extending the service life of the catalyst.

The present disclosure relates to a hierarchical porous titanosilicate molecular sieve containing framework titanium and anatase and a preparation method and application thereof. The titanosilicate molecular sieve has Ti 2p 3 / 2 XPS characteristics: the titanosilicate molecular sieve has spectral peaks at binding energy N1 and N2 positions; wherein the N1 is 459.2±0.2ev, the spectral peak peak area of the titanosilicate molecular sieve at the binding energy N1 position is recorded as A1; the N2 is 460.5±0.5ev, the spectral peak peak area of the titanosilicate molecular sieve at the binding energy N2 position is recorded as A2; X1 defined as below formula (1) is any value between 0.8-2.2ev: X1=N2-N1 formula (1); X2 defined as below formula (2) is any value between 0.1-0.8: X2=A2 / A1 formula (2). The present disclosure can exert the synergistic effect of framework titanium and anatase, can effectively improve the conversion rate of cyclohexanone oxime and the selectivity of caprolactam in the gas phase Beckmann rearrangement reaction of cyclohexanone oxime, and prolong the catalyst life.

The utility model relates to the field of production devices of organic chemical raw materials, and discloses a cyclohexanone oxime preparation device. The device comprises a reaction unit, a washing unit 6, a product separation unit 7 and an extraction unit 8, wherein the reaction unit comprises at least one reactor 1, a reaction cooler 2, a catalyst separator 3 and a membrane filter 4 which is arranged in the catalyst separator 3 or is communicated with a water phase outlet of the catalyst separator 3; the reactor 1 is provided with a raw material inlet communicated with a circulating catalyst slurry pipeline 10 and a hydrogen peroxide inlet communicated with a hydrogen peroxide supply device, and the circulating catalyst slurry pipeline 10 is provided with a cyclohexanone inlet and an ammonia inlet. The device disclosed by the utility model obviously prolongs the service life of the catalyst, effectively removes impurities in cyclohexanone oxime, and has higher cyclohexanone conversion rate and cyclohexanone oxime selectivity.

The application discloses a SiC reactor for cyclohexanone aminooxidation and a design method thereof, and relates to the technical field of chemical reactors. The SiC reactor comprises a reactor shell, a plurality of reaction channels, a plurality of composite plates, and a plurality of reaction channels. The axis direction of the reaction channel is parallel to the axis direction of the reactor shell. The plurality of composite plates are arranged in the plurality of reaction channels. The flat plate and the corrugated plate made of silicon carbide are arranged in the axial direction of the reaction channel and matched with the rhombic through-hole structure. The fluid in the reaction channel can be disturbed, the radial diffusion effect of the fluid is improved, and the effective residence time of the fluid is prolonged. Based on the excellent heat conduction performance of silicon carbide and the plate combination structure, the heat exchange between the wall surface and the fluid is strengthened, the temperature field distribution in the channel is optimized, the mass transfer and heat transfer conditions of the material are improved, and the generation effect of cyclohexanone oxime is improved.

The invention relates to the field of production of caprolactam by Beckmann rearrangement of cyclohexanone-oxime, and discloses a gasification method and system of cyclohexanone-oxime. The method comprises the following steps: gasifying a circulating cyclohexanone oxime liquid phase, inert gas and a first solvent in a gasifier, and then carrying out gas-liquid separation to obtain a first gas-phase material and a liquid-phase material; (2) returning part of the liquid-phase material to the gasifier for gasification; (3) mixing the rest of the liquid-phase material with a second solvent to obtain a mixed solution; then feeding the mixed solution to a fluidized bed to be in contact with solid particles for secondary gasification to obtain solid particles attached with heavy substances and a second gas-phase material; carrying out Beckmann rearrangement reaction on the first gas-phase material and the second gas-phase material; wherein the temperature of the solid particles is at least 20 DEG C higher than that of the mixed liquid. The method provided by the invention can reduce the throwing amount of heavy impurities, improve the utilization rate of cyclohexanone-oxime, reduce the unit consumption of cyclohexanone-oxime, and improve the activity and service life of the catalyst.

The invention relates to the technical field of catalysts, and discloses a ZSM-5 type structure-containing all-silicon molecular sieve catalyst and a preparation method thereof, and a cyclohexanone-oxime gas phase Beckmann rearrangement reaction method, the method comprises the following steps: (1) mixing a silicon source, KOH, an organic alkali and water, and hydrolyzing to obtain a colloid mixture; (2) crystallizing the colloid mixture, and optionally concentrating the obtained crystallization mother liquor to obtain molecular sieve slurry; (3) mixing the molecular sieve slurry with a binder, and pulping to obtain molecular sieve-binder slurry; carrying out spray molding on the molecular sieve-binder slurry, and then roasting; and (4) contacting the product obtained by roasting in the step (3) with an alkaline buffer solution containing ammonium salt, ammonia water, magnesium salt and bromine salt, and then drying. The microsphere type all-silicon-1 molecular sieve catalyst prepared by the method has relatively high cyclohexanone-oxime conversion rate and caprolactam selectivity.

The present disclosure relates to a method for preparing adiponitrile, comprising the following steps: contacting cyclohexanone oxime, an ammonia source and a catalyst to perform a catalytic reaction; the catalyst comprises a hierarchical pore Silicalite-1 molecular sieve, and the hierarchical pore Silicalite-1 molecular sieve has a plurality of cavity structures in the crystal. The present disclosure does not need to use toxic and harmful solvents, and has higher cyclohexanone oxime conversion rate and adiponitrile selectivity.

The present disclosure relates to a kind of multi-level hole pure silicon molecular sieve and its preparation method and cyclohexanone oxime catalytic reaction method.The multi-level hole pure silicon molecular sieve has the following diffusion coefficient characteristics: with cyclohexane as probe molecule, the diffusion coefficient of the probe molecule in the multi-level hole pure silicon molecular sieve is 0.015-0.02 μm 2 / min, measured by zero-length column method.The present disclosure can effectively improve the molecular diffusion performance of molecular sieve, and when the molecular sieve is used for cyclohexanone oxime gas phase Beckmann rearrangement reaction, the selectivity of caprolactam and the service life of catalyst can be effectively improved.

This invention relates to the field of catalyst technology, and discloses a method for preparing a microsphere molecular sieve catalyst and a method for the gas-phase Beckmann rearrangement reaction of cyclohexanone oxime, comprising: (1) carbonizing a waste cyclohexanone oxime gas-phase Beckmann rearrangement catalyst; (2) mixing the obtained product with water and slurrying it until the particle diameter in the slurry is less than 20 μm; (3) mixing the slurry, KOH, an organic template agent, and an alcohol; (4) crystallizing the colloidal mixture, and optionally concentrating the crystallization mother liquor to obtain a molecular sieve slurry; (5) mixing the molecular sieve slurry with a binder and slurrying it, spray-forming the molecular sieve-binder slurry, and then calcining it; (6) contacting the product obtained from calcination in step (5) with an alkaline buffer solution containing ammonium salt, ammonia, magnesium salt, and bromide salt, and then drying it. The catalyst obtained by this preparation method has a high cyclohexanone oxime conversion rate and caprolactam selectivity in a fluidized bed reaction system.

The present disclosure relates to a multi-level pore heteroatomic molecular sieve, a preparation method thereof and application thereof in a gas-phase Beckmann rearrangement reaction of cyclohexanone oxime. The multi-level pore heteroatomic molecular sieve has the following FT-IR characteristics: the peak area of a spectrum peak at a wave number of 3740±5 cm ‑1 in a FT-IR spectrum of the multi-level pore heteroatomic molecular sieve is recorded as A1; the peak area of a spectrum peak at a wave number of 3690±5 cm ‑1 in the FT-IR spectrum of the multi-level pore heteroatomic molecular sieve is recorded as A2; the peak area of a spectrum peak at a wave number of 3520±10 cm ‑1 in the FT-IR spectrum of the multi-level pore heteroatomic molecular sieve is recorded as A3; X1 defined by the following formula (1) is any value between 0.6 and 1.6: X1=A2 / A1 formula (1); X2 defined by the following formula (2) is any value between 2.0 and 5.5: X2=A3 / A1 formula (2). The multi-level pore structure and the heteroatomic active center are introduced into the molecular sieve, the diffusion capacity and the anti-coking deactivation capacity of the molecular sieve are improved, and thus excellent gas-phase rearrangement reaction performance is obtained.

A method for resource utilization of distillation vessel residue. A method for preparing pentanamine is provided, the method comprising the following steps: (1) adding water to the distillation vessel residue obtained in the process of preparing caprolactam by the gas-phase Beckmann rearrangement of cyclohexanone oxime, and heating to dissolve to obtain a homogeneous solution; (2) under a hydrogen atmosphere, introducing the homogeneous solution obtained in step (1) into a fixed-bed reactor filled with catalyst to react and obtain pentanamine.

The invention provides a cyclohexanone-oxime transposition process flow and a cyclohexanone-oxime transposition device for partitioned sulfuric acid concentration supply, which are used for partitioned supply and accurate control of sulfuric acid concentration in different stages of transposition reaction, in the transposition process flow, fuming sulfuric acid is proportionally distributed to a high-concentration acid channel and a low-concentration acid channel through an intelligent metering and acid adding module, and the high-concentration acid channel and the low-concentration acid channel are communicated with the high-concentration acid channel and the low-concentration acid channel; the high-concentration acid channel is used for a one-step transposition reactor of a one-step reaction zone of the two-step transposition process, the low-concentration acid channel is used for a two-step transposition reactor of a two-step reaction zone of the two-step transposition process, and in the transposition process flow, a multi-mode fuzzy self-adaptive prediction PID control algorithm is adopted, control modes are switched according to reaction stages, and the multi-mode fuzzy self-adaptive prediction PID control algorithm is adopted. The first-step reaction zone adopts high-precision temperature-acid concentration cascade control, and the second-step reaction zone adopts by-product prediction feedforward control; according to the invention, partitioned supply and accurate control of sulfuric acid concentration in the first-step reaction zone and the second-step reaction zone can be realized, the reaction efficiency and selectivity are improved, and acid consumption and by-product generation are reduced.

This invention relates to the field of production methods for organic chemical raw materials, and discloses a method and system for preparing cyclohexanone oxime. The method includes: (1) mixing cyclohexanone, ammonia, and a circulating catalyst slurry, and reacting the mixture with hydrogen peroxide to undergo an ammoniation reaction to obtain a reaction slurry; (2) separating a portion of the reaction slurry with an organic solvent to obtain an organic phase and an aqueous phase; (3) washing the organic phase with water to obtain a cyclohexanone oxime-rich stream and a first supernatant, separating the cyclohexanone oxime-rich stream to obtain an organic solvent and cyclohexanone oxime; (4) performing membrane filtration on the aqueous phase to obtain a catalyst-rich stream and a second supernatant; returning the catalyst-rich stream to step (1); (5) extracting the first supernatant and / or the second supernatant with the organic solvent obtained in step (3) to obtain an organic phase, which is then returned to step (2). This method significantly improves the service life of the catalyst, exhibits good operational stability, and produces high-quality cyclohexanone oxime.

The present application relates to a moving bed reactor, in particular to a radial moving bed reactor and a preparation method of caprolactam. The reactor comprises a reactor shell, and a center pipe with through holes, a catalyst bed and a material distributor arranged from inside to outside in the reactor shell; wherein a plurality of heat-removing partitions vertically connected with the pipe wall of the center pipe are arranged along the circumferential direction of the center pipe; an upper ineffective reaction zone, an effective reaction zone and a lower ineffective reaction zone are arranged from top to bottom in the catalyst bed; wherein the part of the center pipe in the upper ineffective reaction zone and the lower ineffective reaction zone is without through holes, and the upper part of the heat-removing partition is arranged as an ineffective part in the upper ineffective reaction zone. The space utilization of the moving bed reactor of the present application is improved, the problem of uneven axial distribution of gas flow is effectively avoided, and the reaction temperature is controlled, which is used in the process of producing caprolactam by gas phase Beckmann rearrangement of cyclohexanone oxime, can reduce the amount of carrier gas, improve the reaction efficiency, conversion rate and selectivity.

The invention discloses a catalyst for preparing caprolactam through cyclohexanone-oxime gas phase rearrangement and a preparation method thereof.The catalyst comprises a molecular sieve carrier and metal components loaded on the molecular sieve carrier, the metal components comprise platinum and auxiliary metal, the mass fraction of platinum in the catalyst is 0.05%-1%, the mass fraction of the auxiliary metal is 0.1%-2%, the mass fraction of the molecular sieve carrier is 0.1%-1%, and the mass fraction of the molecular sieve carrier is 0.1%-1%. And the auxiliary metal is selected from one or more of nickel, copper or cerium. A molecular sieve carrier is pretreated through nitrogen-ammonia mixed gas, an assistant metal salt solution and a platinum precursor solution are loaded step by step by adopting an equivalent-volume impregnation method, and the catalyst is prepared through drying and reduction. The preparation method of the catalyst is simple, the repeatability is good, and the catalyst can effectively improve the conversion rate of cyclohexanone-oxime and the selectivity of caprolactam in the reaction of preparing caprolactam through cyclohexanone-oxime gas phase rearrangement.

The invention relates to a method for recycling gas-phase rearrangement heavy components of caprolactam prepared from cyclohexanone-oxime, which comprises the following steps: carrying out negative pressure distillation on the gas-phase rearrangement heavy components of caprolactam prepared from cyclohexanone-oxime in a rectifying tower, and respectively collecting tower top fraction caprolactam monomers and tower bottoms; the method comprises the following steps: sequentially carrying out alcoholysis reaction and hydrogenation reaction on a caprolactam monomer, and collecting a reaction product 6-aminohexanol; carrying out saponification reaction on the tower bottoms to obtain saponified liquid; and mixing the saponification liquid, 6-aminohexanol, polyhydric alcohol and polyol ether to prepare the grinding aid. According to the method, deep utilization of gas-phase rearrangement heavy components is achieved, the obtained grinding aid is good in grinding aiding effect, and the screen residue reduction amount and the free calcium content reduction amount after calcination at 1450 DEG C are both high.

The application provides a hole disc type liquid phase separator for cyclohexanone oxime liquid phase rearrangement product, which is arranged in the middle of a phase separation tower for liquid phase separation and comprises a liquid distribution disc and a liquid guide pipe, wherein the liquid guide pipe is composed of a support pipe and a phase separation structure which are connected with each other, and the liquid guide pipe is arranged perpendicularly to the liquid distribution disc. The phase separator can strengthen mass transfer and efficiently mix the liquid through the special liquid guide pipe. The space of each stage of the liquid distribution disc forms a uniform phase separation space, so that the purpose of multi-stage extraction is achieved, and the separation work such as single extraction, back extraction and ion exchange can be completed by a single extraction tower. Meanwhile, the phase separator can improve the mixing efficiency and mass transfer performance of the liquid, has the advantages of smaller occupied space, convenient installation and easy adjustment of the horizontal degree.

The present application relates to the technical field of caprolactam preparation, and particularly discloses a method for producing high-purity cyclohexanone oxime and an internal membrane two-stage ammonoxidation reaction system. The cyclohexanone, hydrogen peroxide and ammonia are introduced into a first reactor containing methylene-modified TS-1 molecular sieve, and a first-stage ammonoxidation reaction is carried out at 90-120 DEG C. After 1-5 min, the obtained first-stage reaction liquid is sent into a second reactor, and a second-stage ammonoxidation reaction is carried out at 70-88 DEG C. After solid-liquid separation, a mixed clear liquid containing cyclohexanone oxime and water is obtained. The mixed clear liquid is extracted with toluene, and the extract is subjected to rectification to obtain cyclohexanone oxime. The two-stage differential ammonoxidation reaction is adopted, the first-stage reaction is carried out at high temperature and fast, and the second-stage reaction is carried out at low temperature and mature, and the reaction efficiency is improved by using a specific ammonoxidation catalyst, so that the cyclohexanone oxime is efficiently prepared. The internal membrane separation catalyst is used, so that the catalyst can be completely recovered.

The invention relates to a hierarchical porous titanium silicalite molecular sieve as well as a preparation method and application thereof. The hierarchical porous titanium silicalite molecular sieve has the following 31P MAS NMR characteristics: the peak intensity of a characteristic peak at the chemical shift of-6 + / -1ppm of the hierarchical porous titanium silicalite molecular sieve is marked as N1; recording the peak intensity of a characteristic peak at the chemical shift of-34 + / -1ppm of the hierarchical porous titanium silicalite molecular sieve as N2; recording the peak intensity of a characteristic peak at the chemical shift of-61 + / -1ppm of the hierarchical porous titanium silicalite molecular sieve as N3; x1 as defined by the following formula (1) is any value between 0.15 and 0.30; x1 = N1 / N3 formula (1); and X2 as defined by the following formula (2) is an arbitrary value between 0.10 and 0.25; x2 = N2 / N3 formula (2). When the molecular sieve is used for a cyclohexanone-oxime gas phase Beckmann rearrangement reaction, the selectivity of a reaction product caprolactam can be effectively improved, and the catalytic activity of the titanium silicalite molecular sieve is kept stable under a long-time reaction condition.

The utility model relates to the field of production devices of organic chemical raw materials, and discloses a cyclohexanone oxime preparation device. The device comprises a reaction unit, a water washing unit 6, a product separation unit 7 and an extraction unit 8, wherein the reaction unit comprises at least one reactor 1, a reaction heat collector 2, a catalyst separator 3 and a membrane filter 4 arranged in the catalyst separator 3 or at the downstream of the catalyst separator 3; the reactor 1 is provided with a raw material inlet communicated with a circulating catalyst slurry pipeline 10 and a hydrogen peroxide inlet communicated with a hydrogen peroxide supply device, and the circulating catalyst slurry pipeline 10 is provided with a cyclohexanone inlet and an ammonia inlet. According to the cyclohexanone oxime preparation device, the catalyst is good in stability and low in energy consumption, and efficient separation of the catalyst and a product can be achieved.

The present application relates to the technical field of petroleum chemical industry, in particular to a kind of heterogeneous synthesis device and method of cyclohexanone oxime.The synthesis device of the present application includes vortex reactor, rotating rod and stirrer;By inserting rotating rod in vortex reactor, annular reaction zone with gap size of 0.5mm-5mm is formed, under the dual action of microscale effect and rotating field, mass transfer resistance is reduced, reaction liquid and catalyst particles are fully contacted, and reaction liquid can be broken into smaller droplets under the shear force provided by rotating field, so that the contact area of oil-water two phases is increased, fully emulsified, uniformly mixed, and the flow distribution of catalyst particles is more uniform, the efficiency of catalytic reaction is improved;At the same time, the concentration distribution of hydrogen peroxide in annular reaction zone is controlled by cooperating with multi-stage feeding mode of hydrogen peroxide, so that the concentration of hydrogen peroxide is matched with the rate of catalytic reaction, thereby improving the utilization rate of hydrogen peroxide, and realizing the efficient synthesis of cyclohexanone oxime.

The invention relates to the technical field of chemical industry, and discloses a steam stripping coupling azeotropic rectification method for crude cyclohexanone-oxime, which comprises the following steps: introducing crude cyclohexanone-oxime into a rectifying tower for azeotropic rectification to obtain a tower kettle produced material which has a water content of less than or equal to 300 mass ppm and does not contain ammonia; on the basis of the total mass of the crude cyclohexanone-oxime, the crude cyclohexanone-oxime contains 10 to 30 weight percent of cyclohexanone-oxime, 60 to 80 weight percent of cyclohexane, 0.4 to 0.8 weight percent of water and 0.03 to 0.06 weight percent of ammonia; the azeotropic distillation conditions meet the conditions that the tower top pressure P1 is 30-60 kPa, the tower kettle pressure P2 is 45-65 kPa, the tower top temperature T1 is 40-60 DEG C, the tower kettle temperature T2 is 60-90 DEG C, and the reflux ratio is (0.03-0.2): 1; t2-T1 is greater than or equal to 9 DEG C, and the cyclohexane evaporation ratio is greater than or equal to 16.5%. The method provided by the invention can deeply remove water and ammonia in the crude cyclohexanone-oxime without causing hydrolysis and thermosensitive deterioration of the cyclohexanone-oxime.

This invention relates to the field of catalyst technology and discloses a method for treating spent catalysts and a method for reacting a catalyst with a cyclohexanone oxime gas-phase Beckmann rearrangement, comprising: (1) carbonizing the spent cyclohexanone oxime gas-phase Beckmann rearrangement catalyst; (2) mixing the product obtained in step (1) with water and slurrying until the particle diameter in the slurry is less than 20 μm; (3) mixing the slurry, KOH, an organic template agent, and an alcohol to obtain a colloidal mixture; (4) crystallizing the colloidal mixture and then drying it to obtain molecular sieve powder; (5) optionally mixing the molecular sieve powder with a binder and then rotating it to obtain spherical particles; (6) calcining the spherical particles and then contacting them with an alkaline buffer solution containing ammonium salt, ammonia, magnesium salt, and bromide salt. The catalyst obtained by this treatment method can achieve both high conversion and selectivity in moving bed or fixed bed reaction systems.

The present disclosure relates to a hierarchical-pore Silicalite-1 molecular sieve, a preparation method thereof and an application thereof in cyclohexanone oxime rearrangement reaction. In the FT-IR spectrum of the hierarchical-pore Silicalite-1 molecular sieve, the peak area of the spectrum peak in the range of 3200-3900 cm ‑1 -1 in the range of 3720-3760 cm ‑1 -1 in the range of 3660-3720 cm ‑1 -1 in the range of 3400-3600 cm ‑1 -1 in the range of 3400-3600 cm, is recorded as Q3; X1 defined by the following formula (1) is any value between 0.6 and 1.6: X1=Q2 / Q1 formula (1); X2 defined by the following formula (2) is any value between 2.5 and 4.5: X2=Q3 / Q1 formula (2). The molecular sieve has abundant nest silicon hydroxyl groups, high catalytic activity and catalytic stability, and can effectively improve the selectivity of caprolactam and the service life of the catalyst.

The present disclosure relates to a hierarchical pore all-silica molecular sieve, a preparation method and application thereof. In the hierarchical pore all-silica molecular sieve 1 In the peak separation result of the spectrum peak in the 1-6 ppm chemical shift range of the H MAS NMR spectrum: the peak area of the spectrum peak in the 1.7-1.9 ppm chemical shift range is recorded as A1, the peak area of the spectrum peak in the 2.0-2.2 ppm chemical shift range is recorded as A2, the peak area of the spectrum peak in the 3.1-3.3 ppm chemical shift range is recorded as A3, the peak area of the spectrum peak in the 4.4-4.6 ppm chemical shift range is recorded as A4, and the sum of the A1-A4 peak areas is recorded as A0; X 1‑1 =A1 / A0×100%, X 1‑2 =A2 / A0×100%, X 1‑3 =A3 / A0×100%, X 1‑4 =A4 / A0×100%, X 1‑1 is 5-20%, X 1‑2 is 12-30%, X 1‑3 is 35-60%, X 1‑4 is 12-32%. The present disclosure can effectively improve the selectivity of caprolactam and the service life of the molecular sieve in the cyclohexanone oxime gas-phase Beckmann rearrangement reaction.

The present disclosure relates to a multi-level pore heteroatomic molecular sieve, a preparation method thereof, and an application thereof in a caprolactam reaction. The multi-level pore heteroatomic molecular sieve has the following Raman spectrum characteristics: the peak intensity of a spectrum peak at a wave number of 1120±5 cm ‑1 in a 325 nm Raman spectrum of the multi-level pore heteroatomic molecular sieve is recorded as N1; the peak intensity of a spectrum peak at a wave number of 960±5 cm ‑1 in the 325 nm Raman spectrum of the multi-level pore heteroatomic molecular sieve is recorded as N2; the peak intensity of a spectrum peak at a wave number of 635±5 cm ‑1 in the 325 nm Raman spectrum of the multi-level pore heteroatomic molecular sieve is recorded as N3; X1 defined by the following formula (1) is any numerical value between 0.2 and 1.2: X1=N1 / N3 formula (1); X2 defined by the following formula (2) is any numerical value between 0.4 and 1.6: X2=N2 / N3 formula (2). The present disclosure can significantly improve the caprolactam selectivity of a cyclohexanone oxime gas phase Beckmann rearrangement reaction and the service life of a catalyst.

The application discloses a kind of sheet Silicalite-1 molecular sieve catalyst and its preparation method and application, its b axis length is 50-250nm, BET specific surface area is 300-500m 2 / g, the preparation method is as follows: silicon source, amide compound, organic template agent and water are mixed to obtain colloidal mixture;The colloidal mixture is hydrothermally crystallized to obtain crystallization product;The crystallization product is washed, separated and treated, and then calcined to obtain the sheet Silicalite-1 molecular sieve catalyst.Compared with the silicalite-1 molecular sieve in the prior art, the sheet silicalite-1 molecular sieve in the application has larger external specific surface area and smaller b axis length, and can improve the conversion rate of cyclohexanone oxime and the selectivity of caprolactam when applied to the reaction of preparing caprolactam by gas-phase Beckmann rearrangement of cyclohexanone oxime.

The invention discloses a preparation method and application of a solid acid catalyst for synthesizing caprolactam, and belongs to the technical field of catalysts. The catalyst is an AHPW / UiO-67 solid acid catalyst, defect type UiO-67 serves as a carrier, quaternary ammonium salt type fixed positive potential sites are introduced to the surface of the carrier through amino organosilane grafting and quaternization treatment, and part of salinized phosphotungstic heteropoly acid is fixed to the surface of the carrier in an electrostatic bonding mode. The open metal site in the carrier provides a Lewis acid site, and the heteropoly acid provides a Bronsted acid site, so that a Lewis-Bronsted acid concerted catalysis system is formed. Effective distribution of acidic sites is realized by regulating and controlling the defect structure of the carrier and the salinization degree of heteropoly acid. The catalyst can be used for a liquid-phase Beckmann rearrangement reaction, caprolactam is prepared by taking cyclohexanone oxime as a raw material, and the catalyst has relatively high conversion rate and selectivity, is easy to separate and recover and can be recycled for multiple times.

This invention relates to the field of production methods for organic chemical raw materials, and discloses a method and system for preparing cyclohexanone oxime. The method includes: (1) mixing cyclohexanone, ammonia, and a circulating catalyst slurry, and reacting the mixture with hydrogen peroxide to undergo an ammoniation reaction to obtain a reaction slurry; (2) mixing the reaction slurry with an organic solvent and performing two-phase separation to obtain an organic phase and an aqueous phase; (3) washing the organic phase with water to obtain a cyclohexanone oxime-rich stream and a first supernatant, separating the cyclohexanone oxime-rich stream to obtain an organic solvent and cyclohexanone oxime; (4) performing membrane filtration on the aqueous phase to obtain a catalyst-rich stream and a second supernatant, returning the catalyst-rich stream to step (1); (5) extracting the first supernatant and / or the second supernatant using the organic solvent obtained in step (3), and returning the resulting organic phase to step (2). This method extends the service life of the catalyst, has good operational stability, and produces high-quality cyclohexanone oxime.