9 results about "Beckmann rearrangement" patented technology

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.

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 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.

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 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.

A hierarchical porous all-silica molecular sieve is provided. The 31P MAS NMR spectrum of the molecular sieve shows three characteristic peaks at chemical shifts of −5±1 ppm, −34±1 ppm and −61±1 ppm, wherein the peak intensity of the characteristic peak at the chemical shift of −5±1 ppm is recorded as N1, the peak intensity of the characteristic peak at the chemical shift of −34±1 ppm is recorded as N2, and the peak intensity of the characteristic peak at the chemical shift of −61±1 ppm is recorded as N3, then X1 as defined by formula (1) is in the range of 0.10-0.30; X1=N1 / N3 (1); and X2 as defined by formula (2) is in the range of 0.15-0.45; X2=N2 / N3 (2). When the molecular sieve is used in the gas-phase Beckmann rearrangement reaction of cyclohexanone oxime, the selectivity of the caprolactam product and the catalyst life can be improved.

This invention relates to the field of catalysts for the gas-phase Beckmann rearrangement reaction of cyclohexanone oxime, and discloses a method for preparing the catalyst and the method for the gas-phase Beckmann rearrangement reaction of cyclohexanone oxime. The method includes: mixing a molecular sieve mother liquor, an organosilicate, an organic template agent, and KOH to obtain a colloidal mixture; subjecting the colloidal mixture to a crystallization reaction; separating the obtained crystallization product into a solid-liquid mixture to obtain a wet molecular sieve and a crystallization mother liquor; drying the wet molecular sieve to obtain a raw molecular sieve powder; optionally mixing the raw molecular sieve powder with a binder, and then rotating it to obtain spherical particles; calcining the spherical particles, and then contacting them with an alkaline buffer solution containing ammonium salt, ammonia, magnesium salt, and bromide salt. This catalyst, when applied in fixed-bed or moving-bed reactions, enables long-cycle, continuous production of caprolactam with a high conversion rate of cyclohexanone oxime.

This invention relates to the field of all-silica-1 molecular sieve preparation technology, and discloses a method for preparing all-silica-1 molecular sieves from waste catalysts, all-silica-1 molecular sieves and their applications, comprising: (1) carbonizing the waste cyclohexanone oxime gas-phase Beckmann rearrangement catalyst; (2) mixing the product obtained in step (1) with water and slurrying, and grinding until the particle diameter in the slurry is less than 20 μm; (3) mixing the slurry, KOH, organic template agent and alcohol to obtain a colloidal mixture; the composition of the colloidal mixture satisfies the following: the molar ratio of silicon species, KOH, organic template agent, alcohol and water (calculated as SiO2) is 1:(0.01-0.1):(0.04-0.15):(3.5-20):(15-45); (4) crystallizing the colloidal mixture, and then drying and calcining it. This method can eliminate solid waste, save the amount of silicon source and organic template agent used, and improve the economics of the new gas-phase rearrangement process technology.