50 results about "Beckmann rearrangement" patented technology

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 present invention provides a boron-containing Beta zeolite, a preparation method thereof and an application thereof, belonging to the field of catalyst preparation. The boron-containing Beta zeolite provided by the present invention contains silicon element and boron element; the molar ratio of silicon element to boron element in the boron-containing Beta zeolite is 15-60:1. The boron element introduced in the boron-containing Beta zeolite and the adjustment of the silicon-boron ratio in the present invention reduce the high-temperature acid sites and increase the low-temperature acid sites, thereby reducing the temperature of the Beckmann rearrangement reaction, reducing the synthesis of by-products, and improving the selectivity of cyclohexanone oxime. The results of the examples show that the selectivity of cyclohexanone oxime is 82.8-99.2% when the boron-containing Beta zeolite of the present invention is used for catalysis.

The invention discloses a preparation method of a chiral intermediate (S)-3-methyl-1-tert-butoxycarbonyl-1,4-diazepane for treating ocular hypertension, relating to the technical field of pharmaceutical chemicals. The invention comprises the following steps: using 1-benzyl-3-methylpiperidin-4-one as a starting raw material, performing chiral resolution to obtain an intermediate 1, performing an addition-elimination reaction on the intermediate 1 and hydroxylamine hydrochloride to obtain an intermediate 2, performing a Beckmann rearrangement reaction on the intermediate 2 to obtain an intermediate 3, performing an amino deprotection reaction on the intermediate 3 to obtain an intermediate 4, performing an amino protection reaction on the intermediate 4 and di-tert-butyl dicarbonate to obtain an intermediate 5, and performing a decarbonylation reaction on the intermediate 5 to obtain the (S)-3-methyl-1-tert-butoxycarbonyl-1,4-diazepane. The preparation method has the characteristics of readily available raw materials, a simple process and a high product yield, and is suitable for the industrial production of the (S)-3-methyl-1-tert-butoxycarbonyl-1,4-diazepane.

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 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.

The application discloses a jet flow type rearrangement reaction device and a lactam preparation method, and mainly relates to the technical field of lactam production. The device comprises a reaction tube, a gas nozzle, a gas distributor and a liquid nozzle mechanism are sequentially arranged in the reaction tube from top to bottom, a liquid storage tank is arranged at the bottom end of the reactor and is communicated with the reactor, the gas nozzle is used for spraying the gas phase reactant downward, the liquid nozzle mechanism is used for spraying the liquid phase catalyst from the liquid storage tank upward, the liquid nozzle mechanism comprises at least two liquid nozzles arranged along the height direction, and an acid catalyst supplementing port is arranged at the bottom of the liquid storage tank. The application has the beneficial effects that: through the two-stage jet flow device specially designed, the micro-Bekman rearrangement reaction is carried out in the mode that the continuous liquid flow and the dispersed gas flow collide to form a foam area, the efficient contact of the gas and the liquid is realized, the reaction efficiency is remarkably improved, and the problem of uneven mixing of the reaction raw materials in the prior art is solved.

This invention belongs to the field of organic chemical synthesis technology, specifically relating to a method for synthesizing 2-fluoro-3-aminobenzoic acid, an important chemical intermediate. Specifically, o-nitroaniline is condensed with hydrated trichloroacetaldehyde and hydroxylamine hydrochloride to obtain 2-(hydroxyimino)-N-(2-nitrophenyl)acetamide; the resulting product undergoes an intramolecular Beckmann rearrangement to generate 7-nitroindigo; 7-nitroindigo undergoes Bayer-Villedge oxidation to generate 2-amino-3-nitrobenzoic acid; 2-amino-3-nitrobenzoic acid undergoes diazotization and halogenation reactions to generate 2-fluoro-3-nitrobenzoic acid or 2-chloro-3-nitrobenzoic acid; 2-fluoro-3-nitrobenzoic acid can be further reduced by nitro to obtain 2-fluoro-3-aminobenzoic acid; or, 2-chloro-3-nitrobenzoic acid can be esterified to obtain 2-chloro-3-nitrobenzoic acid ester, which can then be fluorinated, saponified, and reduced to obtain 2-fluoro-3-aminobenzoic acid. The raw materials of this invention are low in cost and readily available, and the entire reaction route has specific regioselectivity, making it suitable for industrial production.

The invention belongs to the field of organic chemical synthesis, and relates to a method for synthesizing a natural product Pyrroloazocine indole alkaloid skeleton. According to the method, a commercially available compound 1 and phenylhydrazine are taken as synthesis starting points, and a [2.2. 2] bridge ring system is constructed through key Fischer indole synthesis, Stille coupling reaction and intermolecular Diels-Alder reaction. The preparation method comprises the following steps: carrying out a cyclopropanation reaction mediated by carbene, carrying out a Ley-Griffith oxidation reaction, and carrying out a Beckmann rearrangement and an intramolecular SN2 cyclization cascade reaction so as to realize the construction of the core skeleton of the Pyrroloazocine indole alkaloid. According to the method, a material basis can be provided for activity testing of the Pyrroloazocine indole alkaloid and the analogue thereof, and a thought is provided for synthesis route design of more complex cage-shaped indole alkaloid basic frameworks.

The invention relates to the technical field of cyclohexanone-oxime gas-phase Beckmann rearrangement reaction, and discloses a cyclohexanone-oxime gas-phase Beckmann rearrangement reaction method and a reaction system, and the method comprises the following steps: (1) in the presence of carrier gas and an alcohol solvent, contacting cyclohexanone-oxime with a catalyst to carry out gas-phase Beckmann rearrangement reaction to obtain a product flow; (2) carrying out tar removal treatment on the product material flow to obtain a first material flow containing caprolactam; (3) carrying out gas-liquid separation on the first material flow to obtain alcohol-rich gas and a second material flow containing caprolactam; (4) carrying out light component removal treatment on the second material flow containing caprolactam to obtain crude caprolactam; the conditions of the cyclohexanone-oxime gas phase Beckmann rearrangement reaction, the tar removal treatment and the gas-liquid separation meet the following conditions: T1 > T2 > T3, P1 > P0 > P2 > P3, and P0 is standard atmospheric pressure, mmHg. According to the method, the purity and the yield of the crude caprolactam can be ensured, and temperature and pressure fluctuation is avoided, so that the process energy consumption is greatly reduced.

The present invention discloses a catalyst for liquid-phase Beckmann rearrangement, its preparation method, and application. The catalyst comprises a macrocyclic compound derivative formed by linking a catalytically active group to a macrocyclic compound having a delocalized macro-π system via a linker. The catalyst can be used to catalyze the Beckmann rearrangement of a ketoxime to obtain the corresponding amide compound, particularly a cyclic ketoxime to produce the corresponding lactam. The catalyst exhibits good catalytic activity, good selectivity, and is easily separable.

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 present invention relates to the field of caprolactam production, and discloses a method for producing high-purity ε-caprolactam. The method comprises the following steps: (1) subjecting cyclohexanone oxime to a gas-phase Beckmann rearrangement reaction; (2) successively performing gas-liquid separation, solvent removal, and light impurity removal on the reaction product obtained in step (1) to obtain crude caprolactam; (3) crystallizing the crude caprolactam to obtain a crystalline product and a crystallization mother liquor; (4) crystallizing the crystallization mother liquor to obtain a crystal slurry; and returning at least part of the crystal slurry to step (2) and / or step (3). The purification method of the present invention can obtain high-purity caprolactam without reducing the overall yield of caprolactam only through one crystallization and one crystallization of the mother liquor. In addition, the method provided by the present invention can effectively solve the problem of product quality fluctuation.

A reactor for directly preparing aminocapronitrile from cyclohexanone oxime comprises a reaction tower, a feeding port is formed in the top of the reaction tower, a discharging port is formed in the bottom of the reaction tower, a supporting plate is arranged in the reaction tower, and an inner cavity of the reaction tower is divided into a heat exchange reaction cavity and a common reaction cavity by the supporting plate. The heat exchange reaction cavity is positioned above the common reaction cavity and is communicated with the common reaction cavity, a heat exchange reaction device is arranged in the heat exchange reaction cavity, and a fixed bed reactor is arranged in the common reaction cavity; according to the utility model, the Beckmann rearrangement reaction and the ammonification reaction are integrated in one reactor, so that not only is the process flow simplified, but also the target product yield of 6-amino-capronitrile is remarkably improved, and the economical efficiency and feasibility of the production process are greatly enhanced.

The invention provides a process and a plant for the production of ε-caprolactam and crystalline ammonium sulfate in an industrial-scale plant, wherein the plant comprises a Beckmann rearrangement reaction section, an ammonium sulfate crystallization section, and one or more heat exchangers configured to transfer heat from the Beckmann rearrangement reaction section to the ammonium sulfate crystallization section and wherein the process comprises the steps of:a) feeding(i) cyclohexanone oxime and(ii) oleum and / or sulfuric acidto the Beckmann rearrangement reaction sectionb) reacting components (i) and (ii) in the Beckmann rearrangement reaction section to form a reaction mixture comprising ε-caprolactam, whereby heat of reaction is generated;c) discharging the reaction mixture comprising ε-caprolactam from the Beckmann rearrangement reaction section;d) removing partially or fully the heat of reaction generated in the Beckmann rearrangement reaction section by one or more heat exchangers configured to transfer heat from the Beckmann rearrangement reaction section;e) feeding an aqueous liquid comprising ammonium sulfate to the ammonium sulfate crystallization section;f) introducing heat into the ammonium sulfate crystallization section comprising the aqueous ammonium-sulfate-comprising liquid by one or more heat exchangers configured to transfer heat into the ammonium sulfate crystallization section;g) forming ammonium sulfate crystals by evaporative crystallization in the ammonium sulfate crystallization section;characterized in thath) the heat of reaction removed from the Beckmann rearrangement reaction section in step d) is at least partially or fully transferred to the ammonium sulfate crystallization section in step f).

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 invention provides a process for inserting amide linkages into a polyolefin, the process comprising the steps of: (i) providing a polyoxime derived from the oxidation of a polyolefin into a polyketone and subsequently converting the polyketone into the polyoxime; and (ii) subjecting the polyoxime to a Beckmann rearrangement reaction in the presence of a dehydrating reagent to obtain a polyamide. The invention also provides a process to provide a reformed polyamide, the process comprising the steps of: (iii) subjecting a polyamide comprising a plurality of amide groups obtained from the process disclosed hereinbefore to hydrolysis conditions to cleave at least a portion of the amide groups to provide an intermediate mixture comprising a plurality of different compounds comprising carboxylic acid groups, amine groups or both; and (iv) generating a reformed polyamide from the intermediate mixture in the presence of a suitable catalyst.

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.

Titanium silicalite molecular sieve with hierarchical porous structure. Titanium silicalite molecular sieve, 1 Peak fitting of the peaks in the 1-6 ppm range in the H MAS NMR spectrum yielded five peaks with chemical shifts of 1.8±0.1 ppm, 2.2±0.1 ppm, 2.8±0.1 ppm, 3.8±0.1 ppm, and 4.6±0.1 ppm, respectively, with the peak areas satisfying a specific proportional relationship. Molecular sieves have significantly improved deactivation resistance, and when used in the vapor-phase Beckmann rearrangement of cyclohexanone oxime, they can significantly improve the conversion of cyclohexanone oxime and the selectivity for caprolactam.

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.

The invention relates to a hierarchical porous titanium silicalite molecular sieve, a preparation method thereof and application of the hierarchical porous titanium silicalite molecular sieve in preparation of caprolactam. The titanium silicalite molecular sieve has the following FT-IR characteristics: in peak division results of an FT-IR spectrogram within the wave number range of 3100-3900 cm <-1 > of the titanium silicalite molecular sieve, the peak area of a spectral peak within the wave number range of 3720-3760 cm <-1 > is marked as Q1, the peak area of a spectral peak within the wave number range of 3660-3720 cm <-1 > is marked as Q2, and the peak area of a spectral peak within the wave number range of 3400-3600 cm <-1 > is marked as Q3; x1 defined by the following formula (1) is any numerical value between 0.8 and 2.2: X1 = Q2 / Q1 formula (1); x2 as defined by the following formula (2) is any numerical value between 2.0 and 5.5: X2 = Q3 / Q1 formula (2). The catalytic performance and the inactivation resistance of the molecular sieve in a catalytic reaction are improved, and the cyclohexanone-oxime conversion rate and the caprolactam selectivity in a cyclohexanone-oxime gas-phase Beckmann rearrangement reaction are improved.

The invention relates to an all-silicon molecular sieve as well as a preparation method and application thereof. The all-silicon molecular sieve has the following 29Si MAS NMR characteristics: the peak area of a characteristic peak in a chemical shift range of-105 to-104 ppm in a 29Si MAS NMR spectrogram of the all-silicon molecular sieve is marked as Q3; marking the peak area of the characteristic peak in the chemical shift range of-114 to-112 ppm in the all-silicon molecular sieve 29Si MAS NMR spectrogram as Q4-1; marking the peak area of the characteristic peak in the chemical shift range of-117 to-115ppm in the all-silicon molecular sieve 29Si MAS NMR spectrogram as Q4-2; x1 as defined by the following formula (1) is any value between 0.1 and 0.35: X1 = Q3 / Q4-1 formula (1); x2 as defined by the following formula (2) is an arbitrary value between 0.35 and 0.75: X2 = Q3 / Q4-2 formula (2). The molecular sieve has a hierarchical pore structure, and can improve the selectivity of caprolactam and prolong the service life of a catalyst in a cyclohexanone-oxime gas-phase Beckmann rearrangement reaction.

The invention discloses a method and a reaction system for liquid-phase Beckmann rearrangement reaction of cyclohexanone oxime catalyzed by solid acid, and belongs to the technical field of caprolactam preparation. The method comprises the following steps: mixing a specific solvent and cyclohexanone-oxime according to a ratio, dewatering, feeding into kettle type reaction equipment, carrying out liquid-solid two-phase rearrangement reaction (the reaction temperature is 80-130 DEG C, the pressure is 50-100Pa, and the retention time is 1-5 hours) under the catalysis of solid acid, directly collecting the product, and generating no ammonium sulfate byproduct. The reaction system comprises a solvent storage tank, a raw material tank, a water removal device, kettle type reaction equipment, a catalyst tank, a condenser, a backwashing tank and a finished product tank, and continuous production can be realized. The method eliminates ammonium sulfate by-products, solves the problem that concentrated sulfuric acid corrodes equipment, and is short in process, low in energy consumption, capable of being transformed based on existing equipment, short in investment payback period and suitable for industrial application, and the caprolactam selectivity is larger than or equal to 99%.

The invention relates to a method for preparing caprolactam from cyclohexanone oxime. The method is characterized in that a catalysis-polymerization inhibition system formed by coupling SO3 and a metal chloride with a caprolactam oligomerization reaction inhibition performance is used for preparing caprolactam through a Beckmann rearrangement reaction of cyclohexanone oxime. The mass ratio of the cyclohexanone-oxime to the SO3 is (1: 4)-(1: 20), and the mass ratio of the cyclohexanone-oxime to the metal chloride is (500: 1)-(20: 1); after the reaction is finished, the SO3 is distilled and recycled under normal pressure and can be repeatedly used; and refining the residue obtained after separation and recovery of SO3 to obtain a caprolactam product. Compared with a traditional method, the method has the advantages that a complex generated through a complexation reaction of SO3 and metal chloride is adopted to catalyze a cyclohexanone-oxime rearrangement reaction and inhibit a caprolactam oligomerization reaction; sO3 is easy to recycle and reuse and has good reusability, and the defect that a large amount of ammonium sulfate is produced as a byproduct in a traditional fuming sulfuric acid catalytic system is overcome.

The application relates to the technical field of catalysts, and discloses a spherical full-silicon molecular sieve catalyst, a preparation method thereof, and a method for gas-phase Beckmann rearrangement of cyclohexanone oxime, which comprises the following steps: (1) mixing a silicon source, an organic alkali and water, performing hydrolysis, and obtaining a colloidal mixture; (2) performing crystallization on the colloidal mixture, and then performing drying to obtain a molecular sieve raw powder; (3) optionally mixing the molecular sieve raw powder with a binder, and then performing rotary molding to obtain spherical particles; and (4) performing calcination on the spherical particles, and then contacting the spherical particles with an alkaline buffer solution containing an ammonium salt, ammonia water, a magnesium salt and a bromine salt; the content of the magnesium salt, calculated according to Mg elements, is 1-500 ppm based on the total amount of the alkaline buffer solution, and the content of the bromine salt, calculated according to Br elements, is 1-500 ppm. In a moving bed or fixed bed reaction system, the spherical ZSM-5 structure full-silicon molecular sieve catalyst has a high conversion rate of cyclohexanone oxime.

This disclosure relates to a hierarchical porous titanium-silicon molecular sieve and its preparation method, as well as a method for preparing caprolactam from cyclohexanone oxime. The titanium-silicon molecular sieve has the following ultraviolet-visible absorption spectral characteristics: In the peak division results of the ultraviolet-visible absorption spectrum of the titanium-silicon molecular sieve in the wavelength range of 200-450 nm: the peak area of ​​the peak at the wavelength position of 210±2 nm is recorded as A1, the peak area of ​​the peak at the wavelength position of 270±5 nm is recorded as A2, and the peak area of ​​the peak at the wavelength position of 320±5 nm is recorded as A3; X1 is any value between 1.5 and 5.1 as defined by the following formula (1): X1=A1 / A2 (1); X2 is any value between 0.5 and 4.5 as defined by the following formula (2): X2=A1 / A3 (2). This titanium-silicon molecular sieve 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 maintain good catalytic performance under long-term reaction, avoiding catalyst deactivation.