259results about "Lactams preparation" patented technology

The invention provides a metal organic sulfonic acid-based solid acid catalyst applied to nylon 6 recovery and depolymerization and a preparation method thereof, and realizes upgrading and recovery of waste nylon 6. The main contents are as follows: (1) a structural design and a preparation method of the metal organic framework sulfonic acid-based solid acid catalyst; and (2) the solid acid is used for catalytic depolymerization of nylon 6. The problems that equipment corrosion is aggravated by inorganic acid in the nylon 6 recovery process and a liquid-phase catalyst is difficult to separate and recover are solved, and the application prospect is good.

The invention provides a hydrolysis method of a waste nylon 6 fishing net. The hydrolysis method comprises the following steps: step 1, screening the waste nylon 6 fishing net, cleaning, removing impurities, disinfecting and crushing; step 2, pretreating diatomite; step 3, adding pretreated diatomite, solid acid and deionized water into a reaction kettle, stirring at 50 DEG C for 5 hours, and removing moisture to obtain a solid acid catalyst; 4, adding the solid acid catalyst, the cleaned waste nylon 6 fishing net and deionized water into a reaction kettle, controlling the temperature and time for reaction, and filtering while hot to obtain a liquid-phase product; 5, neutralizing, decolorizing and extracting the liquid-phase product to obtain a caprolactam monomer; and 6, carrying out polymerization reaction on the obtained caprolactam monomer to generate regenerated polyamide for chinlon spinning. According to the method provided by the invention, the solid acid catalyst is easily separated from reactants, the catalytic efficiency is high, the corrosion to equipment can be reduced, and the method is more environment-friendly.

The invention relates to the field of caprolactam production, and discloses a green and efficient production process and device. The process comprises the following steps: continuously oximating cyclohexanone and hydroxylamine in a microreactor under the catalysis of mesoporous silica solid acid; carrying out gas phase rearrangement on cyclohexanone-oxime in the presence of a ZSM-5 molecular sieve under the assistance of microwaves; coupling, rectifying and purifying the crude product through a four-stage molecular sieve membrane; and performing catalytic cracking on the by-product to obtain N2 / H2O and recycling. The device comprises a micro-reaction unit, a microwave-radial reactor, a membrane coupling rectifying tower group and a tail gas cracking unit. Zero emission of ammonium sulfate is achieved, the product purity is larger than or equal to 99.95%, and energy consumption is reduced by 45%.

The invention discloses a hydroxylamine sulfate preparation method, which comprises: S1, carrying out analysis on caprolactam sulfate with water or a hydroxylamine sulfate aqueous solution to obtain a caprolactam sulfuric acid aqueous solution; extracting and separating the caprolactam sulfuric acid aqueous solution by using an extracting agent, conveying an extraction phase caprolactam organic solution to a caprolactam device for treatment, and entering a step S2 into a raffinate phase sulfuric acid aqueous solution or hydroxylamine sulfate and sulfuric acid aqueous solution; s2, adding ketoxime and a sulfuric acid aqueous solution or hydroxylamine sulfate and the sulfuric acid aqueous solution to generate a hydrolysis reaction to generate a hydroxylamine sulfate aqueous solution and ketone, and after ketone separation, sending the ketoxime to a ketoxime preparation device; s3, carrying out steam stripping separation on the hydroxylamine sulfate aqueous solution, sending unreacted ketoxime to the step S2 to participate in a hydrolysis reaction, and carrying out concentration crystallization, centrifugal filtration and drying dehydration on the hydroxylamine sulfate aqueous solution to obtain hydroxylamine sulfate; and S4, returning part of hydroxylamine sulfate raffinate subjected to centrifugal filtration to the step S1 for resolving caprolactam sulfate, and carrying out oximation reaction treatment on the residual hydroxylamine sulfate raffinate and ketone.

The invention discloses a method for directionally depolymerizing polycaprolactone into a caprolactone monomer, and belongs to the technical field of directional depolymerization of caprolactone. According to the invention, efficient closed-loop depolymerization of polycaprolactone is realized, and generation of dimers is reduced. According to the polycaprolactone depolymerization method provided by the invention, the polycaprolactone can be directionally depolymerized into the caprolactone monomer without a high vacuum degree condition, the depolymerization condition is relatively mild, the process is efficient, and a new way is developed for chemical recovery of waste plastics while the environmental and economic benefits of recycling of the polycaprolactone are improved. The obtained depolymerization product is relatively high in purity, relatively high in conversion rate and low in dimer generation amount, and the depolymerization product can be directly and efficiently recycled.

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.

A process for preparing a liquid high-purity ε-caprolactam stream ST, comprising preparing a liquid stream SC comprising ε-caprolactam, said preparing comprising depolymerizing a material M comprising polyamide 6, said liquid stream SC further comprising one or more oxidizable organic impurity compounds X, wherein the stream SC has an ε-caprolactam purity ΩGC(SC) of at least 99 %; providing a stream SO comprising at least one permanganate; preparing an oxidation reaction educt mixture MOE from the stream SC and the stream SO, and subjecting the mixture MOE to oxidation reaction conditions, obtaining an oxidation reaction product stream SP comprising ε-caprolactam, further comprising one or more oxidation products Y obtained from the oxidation of at least a part of the one or more compounds X, and optionally further comprising a part of the one or more organic compounds X; separating at least a part of the one or more oxidation products Y and optionally at least a part of organic compound X from the stream SP, obtaining the stream ST exhibiting an ε-caprolactam purity ΩGC(ST) of at least 99.5 % with ΩGC(ST) > ΩGC(SC), and an APHA value ΩGC(ST) of at most 10.

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 invention relates to a method for preparing caprolactam, which is characterized in that: a # imgabs0 # acidic compound with temperature control phase transfer catalysis characteristics is adopted as a catalyst to catalyze cyclohexanone-oxime rearrangement reaction to prepare caprolactam, and the catalyst is recycled and reused; the conditions of the rearrangement reaction are as follows: the molar ratio of cyclohexanone-oxime to the catalyst is (10: 1)-(200: 1), the mass ratio of cyclohexanone-oxime to the organic solvent is (1: 1)-(1: 5), the reaction temperature is 40-150 DEG C, and the reaction time is 1-8 hours. The method has the characteristics that the # imgabs 1 # acidic compound with the temperature control phase transfer catalysis characteristic is used as a catalyst to catalyze cyclohexanone-oxime rearrangement reaction to prepare caprolactam, and has the characteristics of high-temperature homogeneous reaction-low-temperature two-phase separation; the reaction conditions are mild, the catalyst has good catalytic activity, the product yield is high, and the solvent and the catalyst are easy to separate and can be used.

The utility model discloses a simple continuous flow microreactor device with replaceable packing. The simple continuous flow microreactor device comprises a liquid pipeline system, a gas pipeline system, a microreactor and a cooling and product collecting system, the micro-reactor is a filler type micro-reaction tube, the filler type micro-reaction tube comprises a tube body, the tube body is filled with a replaceable porous filler, and the porous filler has both a microporous structure and a mesoporous structure; filtering sieve plates for intercepting porous fillers with different sizes are respectively arranged at the upper end and the lower end of the pipe body, and are respectively connected with the material inlet and outlet joint through fixing pieces for stabilizing the fillers; a blade ring and a sealing ring are sequentially arranged between the fixing piece and the pipe body from top to bottom. The microreactor disclosed by the utility model is applied to preparation of amide compounds, and compared with a conventional microreactor, the microreactor disclosed by the utility model can obtain higher product yield.

The present invention relates to the chemical industry field, and particularly relates to a method for synthesizing valerolactam. The steps are as follows: cyclopentanone and the reaction auxiliary cyclohexanone are mixed in a certain proportion, and then through ammoximation reaction, Beckmann rearrangement reaction, hydrolysis and neutralization reaction, and then through separation, valerolactam is obtained. The method of the present invention has a high atom utilization rate and a high product extraction rate, and has the prospect of actual industrial production.

The invention belongs to the technical field of high polymer material recovery, and particularly relates to a method for degrading nylon 6 or a similar polymer thereof into a lactam monomer. The method comprises the following steps: placing waste nylon 6 or a similar polymer thereof, an activation accelerator and an alcohol solvent in a closed reaction container according to a certain proportion, reacting for a period of time at a certain temperature, and evaporating to remove the solvent to obtain a first-step degraded crude product; recrystallizing the degradation crude product obtained in the first step to obtain a pure alcoholysis product; or directly carrying out a second-step cyclization reaction, namely putting the first-step degradation product, alkali, an additive and a solvent into a closed container, reacting at a certain temperature, directly filtering to remove filter residues, and evaporating the solvent in the obtained solution to dryness to obtain the high-purity lactam monomer. According to the invention, nylon 6 or similar polymers thereof can be degraded into corresponding lactam synthetic monomers with high efficiency and high selectivity, the operation is simple, the condition is mild, the post-treatment is simple and convenient, and the method is suitable for large-scale industrial application.

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 invention relates to the technical field of chemical engineering, and discloses an amide oil separation and ammonium sulfate crystallization integrated device. Comprising a neutralization reactor, a settling separation tank, a pre-crystallization solution tank, a DTB crystallizer, a centrifugal machine, a settling separator, a dryer, a mother liquor tank, a condensate water tank, an amide oil decanter, an ammoximation tert-butyl alcohol tower reboiler, a mother liquor heater set, a condenser, a vacuumizing condensing unit, a stirrer set and a reactor circulating pump. The invention further comprises a process for preparing the large-particle ammonium sulfate crystal from the saturated amide oil solution, rearrangement liquid from a lactam rearrangement system and gas ammonia are added into a neutralization reactor through an external circulation pipeline, and the large-particle ammonium sulfate crystal is prepared by fully utilizing heat in the gas ammonia dissolution and neutralization reaction and crystallization process. By combining the compound additive, the seed crystal and the continuous crystallization technology, the generation of large-particle ammonium sulfate crystals is promoted, meanwhile, the crystallization process is optimized, an efficient amide oil separation and continuous crystallization mode is realized, the energy consumption is saved, and the production efficiency is improved.

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 system for preventing ammonium sulfate blockage in caprolactam production comprises an elutriator and an amide oil storage tank, the elutriator is communicated with the upper portion of the amide oil storage tank through a second delivery pump, and the amide oil storage tank is communicated with a benzene extraction tower through a middle lower discharge pipeline connected with a fourth delivery pump. The lower part of the amide oil storage tank is communicated with the crystallizer through a third delivery pump, and the treatment system is characterized in that the treatment system comprises a first benzene injection pipe arranged between the elutriator and the second delivery pump and / or a second benzene injection pipe arranged between the second delivery pump and the amide oil storage tank; and benzene enters the second delivery pump through the first benzene injection pipe and / or benzene enters the amide oil storage tank through the second injection pipe. The utility model has the advantage that the problem that the pipeline is blocked due to ammonium sulfate crystallization precipitation when the amide oil is extracted can be solved.

The invention provides a preparation method and application of a solid acid catalyst for cyclohexanone-oxime gas phase rearrangement, and the method comprises the following steps: in the presence of a solvent, mixing and stirring a silicon source, an amine modifier and an activator for reaction; mixing the obtained reaction liquid with an acid treatment agent, and stirring while keeping the temperature; after heat preservation is finished, adding a strong acid modifier, continuously sealing, preserving heat and stirring, and after heat preservation is finished, evaporating the solution to dryness to obtain a catalyst precursor; and roasting the catalyst precursor to obtain the strongly acidic solid acid catalyst. The catalyst has good catalytic performance in the reaction process of preparing caprolactam through cyclohexanone-oxime gas phase rearrangement, the cyclohexanone-oxime conversion rate is high, caprolactam selectivity is high, impurities are few, the service life of the catalyst is long, generation of ammonium sulfate in a traditional technology is avoided, economic benefits are good, cost is low, and the catalyst is environmentally friendly.

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 present invention provides a process for recovering ε-caprolactam and polyether polyurethane from nylon 6 and polyether polyurethane comprising material 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 invention relates to a method for preparing a mixture containing cyclohexanol and cyclohexanone, comprising the step of hydrogenating cyclohexyl hydroperoxide in cyclohexane in the presence of a Raney nickel catalyst to obtain cyclohexanol and cyclohexanone.

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.

The present invention provides a composite silicon molecular sieve catalyst, a preparation method and application thereof. The preparation method comprises the following steps: S1, mixing an organosilicon compound, a quaternary ammonium template and water, and then sequentially performing a hydrolysis reaction, a distillation and a crystallization reaction to obtain a solid-liquid mixture; S2, adjusting the solid-liquid mixture to neutral or alkaline, and then filtering to obtain a filter cake and a filtrate; S3, performing a first roasting of the filter cake to obtain a roasted solid material; S4, mixing the roasted solid material with graphene oxide, an organic amine and a solvent, performing a composite modification treatment, and then performing solid-liquid separation to obtain a modified solid material and a liquid phase; S5, performing a second roasting of the modified solid material to obtain a composite silicon molecular sieve catalyst. The composite silicon molecular sieve catalyst prepared by the present invention can take into account high selectivity, long service life, low energy consumption and easy industrial production.

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.

The present invention provides an improved process for recovering ε-caprolactam from multicomponent materials, in particular multilayer films, comprising nylon 6. Furthermore, the present invention provides a plant adapted to carry out the process of the present invention, and recovered ε-caprolactam obtainable by the process of the present invention, having a product carbon footprint of less than 2.5 kg CO2 equivalent per kg purified ε-caprolactam (based on Eco Invent version 3.7.1 (region: Europe) data).

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.