336results 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 relates to a method for efficiently hydrolyzing nylon 6 by acid catalysis, and relates to the technical field of hydrolysis of nylon 6, the method comprises the following steps: carrying out hydrolysis reaction on nylon 6, water and an acid catalyst in a closed state to obtain a hydrolysis product; and carrying out purification post-treatment on the hydrolysis product to obtain caprolactam, the reaction pressure of the hydrolysis reaction is controlled in a self-boosting manner; the specific process of the self-boosting mode comprises the step of changing the pressure of the hydrolysis reaction system by adjusting the adding mode of the water. The nylon 6 hydrolysis process provided by the invention is simple, hydrolysis reaction pressure is controlled mainly by a self-boosting control method of a reaction system by controlling a water adding mode, other raw materials do not need to be added, efficient hydrolysis of nylon 6 is realized, and the nylon 6 hydrolysis process has the characteristics of short hydrolysis reaction time, high depolymerization rate and the like, and is suitable for industrial production. The method effectively solves the technical problems of long hydrolysis reaction time and low depolymerization rate in the existing process for catalyzing and hydrolyzing nylon 6 by using an acid method.

The invention relates to a nylon 6 polymerization production method capable of fully recycling extractable oligomers, and relates to the technical field of nylon 6 polymerization production processes, the nylon 6 polymerization production method comprises a nylon 6 polymerization section, a nylon 6 slice extraction section, a nylon 6 wet slice drying section, an extract evaporation and concentration section and an extractable oligomer cracking and recycling section; in an extractable oligomer cracking and recycling section, by adjusting process conditions such as temperature, pressure and water content of an oligomer extraction concentrated solution, deep cracking of extractable substances is realized, and all cracking products can be recycled into a polymerization section for recycling, so that rapid accumulation of cyclic dimers in polymers is inhibited, no residues are generated in the polymerization process, and the production cost is reduced. Accumulation of cyclic dimers in a system can be effectively slowed down, the service life of a polymerization reactor is prolonged, and the quality of polymer products is improved.

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 present invention provides an improved process for the recovery of ε-caprolactam from Nylon 6 comprising multi-component material, in particular multi-layered film. Further, the invention provides a plant configured to carry out the process of the invention, and the recovered e-caprolactam obtainable by the process of the invention that has a product carbon footprint of less than 2.5 kg CO2 equivalent per kg purified e-caprolactam (based on data originating from ecoinvent version 3.7.1; location: Europe).

A process for preparing purified ε-caprolactam from polyamide 6 contained in a solid material M, wherein the process comprises preparing an aqueous liquid stream comprises ε-caprolactam, subjecting this liquid stream to depressurization in an evaporation unit from which aqueous vapor streams SEV1, SEV2 and SEV3 are obtained which have different pressures and which are then used as heat source for heat-consuming purification units used for preparing a purified ε-caprolactam.

The invention relates to the field of preparation of molecular sieves, and discloses a preparation method of an all-silicon molecular sieve with an MFI topology structure, the all-silicon molecular sieve with the MFI topology structure and application of the all-silicon molecular sieve with the MFI topology structure, the method comprises the following steps: (1) mixing molecular sieve mother liquor, organic silicate ester, an organic template agent and alcohol to obtain a colloid mixture; the mass ratio of SiO2 in the molecular sieve mother liquor to the organic silicate ester based on SiO2 is (0.01-0.2): 1; the molar ratio of the alcohol to SiO2 in the molecular sieve mother liquor is (10-100): 1; (2) carrying out crystallization reaction on the colloid mixture; (3) carrying out solid-liquid separation on the crystallization product obtained in the step (2) to obtain a molecular sieve wet material and crystallization mother liquor; drying and roasting the molecular sieve wet material; and (4) optionally concentrating the crystallized mother liquor, and then returning to the step (1). The preparation method can effectively utilize the molecular sieve mother liquor, saves the cost, is beneficial to environmental protection, and is easy to operate.

The present invention provides a process and a plant for recovering purified ε-caprolactam from nylon 6 comprising fishing nets, wherein the plant comprises a depolymerization section [B], a recovery section [C], and a purification section [D]. The present invention also provides purified ε-caprolactam that has a particularly low product carbon footprint and is obtained via depolymerization of nylon 6 from fishing nets. In a second preferred embodiment, the purification of the distilled caprolactam is achieved by crystallization in a process of concentrating. The crystallized caprolactam resulting from concentrating is generally sufficiently pure to be used directly. After crystallization, it may be necessary to purify the mother liquor by, for example, recycling it to the aqueous solution before the extraction with the alkyl phenol. The mother liquor can be purified for example by means of distillation.

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 invention provides a method for recovering epsilon-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 invention discloses a filler-replaceable continuous flow microreactor device and application of the filler-replaceable continuous flow microreactor device in amide preparation reaction. The continuous flow micro-reactor device with the replaceable filler comprises a micro-reactor, the top of the microreactor is respectively communicated with a liquid pipeline system and a gas pipeline system, and the bottom of the microreactor is connected with a cooling and product collecting system; the micro-reactor is a filler micro-reaction tube, the filler micro-reaction tube comprises a tube body, and the tube body is filled with a replaceable porous filler; the upper end and the lower end of the pipe body are respectively provided with filtering sieve plates for intercepting porous fillers with different sizes, and the filtering sieve plates at the two ends are respectively connected with a material inlet and outlet joint through fixing pieces. The invention provides application of a replaceable filler type continuous flow microreactor device in an amide preparation reaction, solves the problems of frequent replacement, easy blockage and high production cost of a common microreactor in the amide preparation reaction, and can improve the reaction efficiency and selectivity.