146results about "Lactams preparation" patented technology

Disclosed is a process for hydrolytic depolymerization of a polyamide contained in a chemical feedstock F, wherein the process comprises: providing the chemical feedstock F; providing a liquid aqueous stream SW; preparing a mixture comprising the raw material F and the liquid aqueous stream SW and subjecting said mixture to polyamide 6 depolymerization conditions in a chemical reaction unit UR, thereby obtaining an aqueous stream SE exiting the UR, the stream SE comprising epsilon-caprolactam, wherein the mixture to be subjected to polyamide 6 depolymerization conditions comprises polyamide 6 and further comprises polyethylene terephthalate and polyamide 6.6 in a mass ratio rS = (mPA6.6 + mPET) / mPA6, wherein 0.01 < = rS < = 2.5.

The present invention belongs to the technical field of petrochemical catalysis, and relates to a preparation method for improving the stability of a Cu-Beta zeolite catalyst for preparing caprolactam from caprolactone, and the use thereof. In the present invention, a cavity-modified dealuminated Beta zeolite is used as a carrier, and copper is loaded in pore channels of the zeolite carrier by means of an improved ammonia distillation method. The cavity modification refers to subjecting the dealuminated Beta zeolite carrier to a desiliconization technique controlled by the use of a weak organic base so as to enlarge silanol nests generated by dealumination of the dealuminated Beta zeolite carrier, thereby better accommodating and stabilizing the nano and sub-nano copper particles. The core of the improved ammonia distillation method involves impregnating a zeolite carrier with an equal volume of a copper-ammonia complex solution, such that the copper-ammonia complex mainly undergoes, during ammonia distillation, a reaction of depositing copper hydroxide in zeolite pore channels, thereby improving the sintering resistance. The Cu-Beta catalyst prepared using the method provided by the present invention exhibits high activity, selectivity and stability when applied to the reaction of caprolactam prepared from caprolactone via gas-solid phase hydroamination.

The present invention provides a method for recovering ε-caprolactam and polyether polyurethane from a material comprising nylon 6 and polyether polyurethane in a plant, wherein the plant comprises a separation section [B], a depolymerization section [C], a recovery section [D], and a purification section [E].

The present application belongs to the technical field of recycling of waste textiles, and particularly relates to a method for recycling waste nylon textiles, comprising: mechanically crushing the waste nylon textiles to obtain nylon fragments; mixing the nylon fragments, polyacrylic acid, metal or its compound, and then, under inert atmosphere and stirring, heating to 60-120 DEG C for 0.5-2 hours, and then, continuously heating to 220-300 DEG C, and catalytically depolymerizing under 1-5 MPa to obtain depolymerate; wherein the metal element of the metal or its compound is a metal having coordination ability with carbonyl; purifying the depolymerate to obtain caprolactam. The present application uses one-step mixing and two-step heating process, and the catalyst exists in the form of coexistence of metal coordination sites and carboxyl, so that the catalyst simultaneously plays the metal coordination activation role and the amide bond breaking and exchange reaction participated by carboxylic acid in the depolymerization process, forming a synergistically promoted efficient depolymerization mechanism, and effectively improving the efficiency of catalytic depolymerization.

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.

A method of depolymerizing a polyamide is provided. In some embodiments, the method includes combining a polyamide and an alkali metal catalyst to depolymerize the polyamide to a product, where the alkali metal catalyst is selected from catalysts having the formula MXRn, where M is an alkali metal, X is H, C, N, Si or Sn, R is independently selected from hydrogen, alkyl, silyl, and aryl, and n is 0-2.

This disclosure relates to a process for the synthesis of a compound of formula (I): (I) wherein w, x, y, and z are as defined in the description. The process includes the reaction of a compound of formula (II): (II) with carbonyldiimidazole, and the reaction of the resulting compound with propargylamine.

This invention relates to the field of caprolactam preparation technology, specifically a method for preparing a porous perfluorosulfonic acid resin catalyst and its application in the liquid-phase Beckmann rearrangement to produce caprolactam. The method uses cyclohexanone oxime as a raw material, and one or more of isopropanol, n-butanol, acetonitrile, formamide, acetone, dioxane, tetrahydrofuran, ethyl acetate, N,N-dimethylformamide, and dimethyl sulfoxide as solvents. The porous perfluorosulfonic acid resin is used as the catalyst. The molar ratio of solvent to cyclohexanone oxime is (2-10):1, and the catalyst content is 0.1-0.5%. The reaction is carried out in a batch reactor under mechanical stirring, with a reactant residence time of 1-5 hours, a reaction temperature of 90-110°C, and a slightly positive pressure. After the reaction, the conversion rate of cyclohexanone oxime is ≥50%, dimethyl sulfoxide does not participate in the reaction, and the selectivity of caprolactam is ≥99%.

The present invention relates to a process for recovering epsilon-caprolactam from a nylon 6-containing multi-component material. The present invention provides an improved process for the recovery of epsilon-caprolactam from nylon 6-containing multi-component materials, in particular multilayer films. Furthermore, the invention provides: a plant configured to carry out the method of the invention; and the recovered [epsilon]-caprolactam obtainable by the process of the invention having a product carbon footprint of less than 2.5 kg CO2 equivalents per kg of purified [epsilon]-caprolactam.

The application provides a purification process method and device of a lactam, wherein an oxime is subjected to a rearrangement reaction with a catalyst, the obtained lactam is purified after the rearrangement reaction, and the method comprises the following steps: extracting the lactam by using an extraction solvent to obtain a lactam solution from which the catalyst is separated, performing alkali washing and water washing on the obtained lactam solution to obtain a lactam solution after alkali washing and water washing, performing hydrogenation reaction on the obtained lactam solution again, performing crystallization separation on the lactam solution after hydrogenation to obtain a lactam product crystal, and then performing treatment on the obtained lactam product crystal by means of solvent washing, rectification, distillation or crystallization to obtain the lactam with a purity of greater than or equal to 99.9%.

To provide a method for manufacturing a cyclic lactam that can manufacture the cyclic lactam with high selectivity, and a device for manufacturing a cyclic lactam. A method for manufacturing a cyclic lactam, the method including performing a depolymerization reaction by using 1 part by mass or more of a polyphosphoric acid per 100 parts by mass of a polyamide resin containing a repeating unit represented by Formula (a). In Formula (a), n1 is an integer of 3 to 22, and n1 may be a different value for each of the repeating unit.

A process for hydrolytically depolymerizing polyamide 6 prepared from ε-caprolactam, the process comprising (i) providing a chemical feedstock F comprising the polyamide 6 and further comprising at least one further organic polymeric compound; (ii) providing a liquid aqueous stream Sw; (iii) admixing the feedstock F with the stream Sw and subjecting the obtained mixture to polyamide 6 depolymerization conditions in a reaction unit UR, obtaining an aqueous stream SE comprising ε-caprolactam and one or more decomposition products of one or more of the at least one further organic polymeric compound; (iv) generating an aqueous stream SR comprising at least part of the water and at least part of at least one of the one or more decomposition products comprised in the stream S, said stream SR; (v) feeding at least part of the aqueous stream SR back to the chemical reaction unit UR.

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.

This invention discloses a kinetically controlled method for preparing hierarchical porous molecular sieves, belonging to the field of catalyst preparation technology. It employs a two-step crystallization method: first, nucleation occurs at low and ultra-low H2O / SiO2 molar ratios; then, after the low-temperature phase, water is added, followed by rapid growth at high temperature and high H2O / SiO2 molar ratios. The solid-phase and liquid-phase crystallization mechanisms in the synthesis system work in succession to prepare hierarchical molecular sieves. This invention, without adding any mesoporous pore-forming agents, only modulates the crystallization temperature and the H2O / SiO2 molar ratio of the synthesis system to kinetically control the crystallization mechanism, resulting in molecular sieves with higher catalytic performance than those obtained using traditional methods. Furthermore, it overcomes the drawbacks of traditional hierarchical porous molecular sieve preparation processes, such as high cost, high calcination energy consumption, poor mesopore connectivity, and severe contamination from pore-forming agents.

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 application relates to the field of molecular sieves, and discloses a ZSM-5 molecular sieve, a preparation method and application thereof, and a catalytic cracking method of triisopropylbenzene. The ZSM-5 molecular sieve has a cross-assembled aggregate crystal morphology formed by sheet-shaped nanocrystals, and the sheet-shaped nanocrystals adjacent to each other in the molecular sieve have a cross-assembled aggregate crystal morphology formed by 90 DEG + / -10 DEG rotation symbiosis and 30 DEG + / -5 DEG rotation symbiosis.

The present application relates to the technical field of polymer material chemical recycling, and in particular to a kind of nano-enzyme catalyst and process for its use in hydrothermal method degradation polycaprolactam.The nano-enzyme catalyst provided by the present application uses specific single metal or double metal combination as metal center, and is combined with specific organic ligand, can be efficiently and deeply degraded PA6 at relatively low temperature, and the catalyst can also be recycled, completely realizing the green recycling of PA6.The nano-enzyme catalyst provided by the present application can make the conversion rate of PA6 molecule reach 100% using hydrothermal method, and the caprolactam yield can be stably above 94%, avoiding the use of organic solvent with high toxicity, and realizing the whole green recycling from " waste containing PA6" to " renewable caprolactam monomer".

The application provides a photochemical reactor, method and system with total reflection characteristics, and relates to the technical field of photochemistry.The application aligns a light source with the direction of a reaction fluid, and uses total reflection conditions to constrain light energy in a reaction system, thereby forming an orderly propagating optical waveguide structure, and fundamentally solving the problem of serious loss caused by disordered scattering of light energy, wall absorption and transmission in the prior art.Orderly and efficient use of light energy enables faster reaction rate under the same light intensity, or higher light intensity can be used under small pipe diameter, thereby greatly improving reaction efficiency and shortening reaction time.The reactor structure of the application is only a simple pipe structure, and does not need complex optical fiber coupling or nested channels, and linear amplification can be realized through simple series connection or parallel connection without obvious adverse amplification effect.Two total reflection modes can be flexibly selected to adapt to reaction systems with different refractive indexes, are widely applicable, and have simple structure and low energy consumption, and meet the requirements of green chemistry.

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.

The present invention relates to a method for amorphizing a material comprising at least one polymer, comprising the following steps: a) adding the material to a solution S1 containing at least one salt and having a pH less than or equal to 7; b) exposing the solution S1 to a temperature T1 greater than or equal to 20°C; c) maintaining the material in said solution S1 until the polymer is amorphized; d) adjusting the pH of the solution S1 to a pH greater than or equal to 4 or transferring the material obtained into a solution S2 containing at least one salt and having a pH greater than or equal to 4 and in which the mass concentration of salt is greater than or equal to 10% by weight relative to the total weight of the solution S2.

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 invention provides a method and a plant for recovering purified ε-caprolactam from fishing nets containing polyamide 6, said plant comprising a depolymerization section [B], a recovery section [C] and a purification section [D]. The present invention also provides purified ε-caprolactam obtained via depolymerization of polyamide 6 from fishing nets, having a particularly low product carbon footprint.

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.

A process for hydrolytic depolymerization of polyamide 6 contained in a solid material M, the process comprising providing the solid material M; melting the solid material M in a melting unit UM, thereby obtaining a liquid stream SM having a temperature TSM at a pressure pSM; providing a liquid aqueous stream SW having a temperature TSW at a pressure pSW; mixing the stream SM with the stream SW in a pre-reaction unit UPR, thereby obtaining a liquid reaction feed stream SF having a temperature TSF at a pressure pSF; feeding the stream SF into a chemical reaction unit UR; subjecting the stream SF to polyamide 6 depolymerization conditions comprising a polyamide 6 depolymerization temperature TD at a polyamide 6 depolymerization pressure pD in the reaction unit UR, thereby obtaining in the UR an aqueous depolymerization mixture comprising epsilon-caprolactam dissolved in water; removing an aqueous liquid reactor outlet stream SR from the UR, the stream SR comprising epsilon-caprolactam dissolved in water; wherein 0.8 < = TSF / TD < = 1.05 and 0.9 < = pSF / pD < = 1.05.

The invention discloses a method for catalyzing waste nylon 6 to be depolymerized into caprolactam, and belongs to the technical field of polyamide waste material depolymerization. The problems that an existing nylon 6 depolymerization method lacks a cheap, easily available and efficient catalytic system, and the purity of caprolactam monomers obtained by catalyzing nylon 6 depolymerization is low are solved. Sodium caprolactam or potassium caprolactam which is cheap, easy to obtain and low in cost and can be prepared from caprolactam, sodium hydroxide / potassium hydroxide, sodium alkoxide / potassium alkoxide and the like through simple process steps is adopted as a depolymerization catalyst, participation of additional solvents such as water is not needed, and the caprolactam is efficiently depolymerized through nylon 6 under the reduced pressure heating condition; the catalyst is prevented from remaining in the product, the purity of the recovered monomer is high, the monomer product can be directly recycled, and the recycling efficiency of the nylon 6 is improved.

A titanium silicalite molecular sieve with a hierarchical porous structure is provided. The spectral peaks of the 1H MAS NMR spectrum of the titanium silicalite molecular sieve in the chemical shift range of 1-6 ppm are separated to obtain five spectral peaks whose chemical shifts corresponding to the peak positions are 1.8±0.1 ppm, 2.2 ppm±0.1 ppm, 2.8 ppm±0.1 ppm, 3.8±0.1 ppm and 4.6±0.1 ppm, respectively. The peak areas of the peaks satisfy specific proportional relationships. The molecular sieve has significantly enhanced anti-deactivation performance and can significantly improve the cyclohexanone oxime conversion rate and the caprolactam selectivity when used in the cyclohexanone oxime gas-phase Beckmann rearrangement reaction.

The present invention provides an improved process for the recovery of epsilon-caprolactam from a multi-component material, in particular a multi-layer film, containing nylon 6. Furthermore, the present invention provides: a plant configured to carry out the process of the present invention; and the recovered epsilon-caprolactam obtainable by the process of the present invention having a product carbon footprint of less than 2.5 kg CO2 equivalent per kg of purified epsilon-caprolactam (based on data from ecoinvent version 3.7.1 ; location: Europe).

To provide a method for manufacturing a cyclic lactam that can manufacture the cyclic lactam with high selectivity, and a device for manufacturing a cyclic lactam. A method for manufacturing a cyclic lactam, the method including performing a depolymerization reaction by using 1 part by mass or more of a polyphosphoric acid per 100 parts by mass of a polyamide resin containing a repeating unit represented by Formula (a). In Formula (a), n1 is an integer of 3 to 22, and n1 may be a different value for each of the repeating unit.

Provided are methods for depolymerizing polyamides. In embodiments, such a method comprises combining a polyamide and an alkali metal catalyst to depolymerize the polyamide to a product, wherein the alkali metal catalyst is selected from those having a formula MXRn, wherein M is an alkali metal; X is H, C, N, Si, or Sn; R is independently selected from hydrogen, alkyl, silyl, and aryl; and n is from 0 to 2.