62results about "Lactams separation/purification" patented technology

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 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%.

The invention provides a caprolactam flash evaporation system and a flash evaporation process. The caprolactam flash evaporation system comprises a separation kettle and a flash evaporation tank which are sequentially communicated, a liquid phase outlet pipe of the flash evaporation tank is communicated with a buffer tank, a gas phase outlet pipe of the flash evaporation tank is communicated with a mixer, an outlet pipe of the mixer is communicated with a condenser, and the condenser is provided with a vacuum pump for keeping an internal vacuum state. The method has the beneficial effects that by improving a current vacuum flash evaporation system and abandoning an ejector with great water consumption, efficient utilization of steam and condensate is realized, energy conservation and improvement of environmental protection benefits are greatly promoted, and by reducing the generation amount of the steam condensate, the burden of subsequent wastewater treatment is relieved, and the production cost is reduced. The potential environmental pollution risk is reduced from the source, the green production and sustainable development goals of enterprises are favorably realized, and greater economic benefits are created for the enterprises.

This invention belongs to the field of pharmaceutical chemistry technology, specifically relating to a monopravir-caprolactam cocrystal, its preparation method, and its applications. The monopravir-caprolactam cocrystal is composed of monopravir and caprolactam in a molar ratio of 1:1.9-2.1. X-ray powder diffraction was performed using Cu-Kα radiation, with angles expressed as 2θ±1, at 6.91, 7.09, 8.38, 11.24, 12.52, 13.26, 13.87, 14.24, 15.22, 16.82, 17.31, and 1... Characteristic peaks are observed at 9.73, 20.22, 20.53, 20.84, 21.90, 22.28, 22.52, 22.95, 23.51, 23.75, 24.00, 24.31, 24.86, 25.35, 26.44, 27.41, 28.02, 28.69, 29.22, 29.84, and 30.33. Monopravir-caprolactam cocrystals can be successfully prepared by grinding and / or solution methods, and grinding and / or melting methods. The preparation process is simple, and the obtained product has high purity. Characterization has confirmed it to be a new cocrystal. Powder flowability and tableting tests revealed that the monopravir-caprolactam cocrystals provided by this invention have better flowability and tableting properties compared to monopravir crystal form I, meeting the requirements of formulation and manufacturing processes.

The invention relates to a method for purifying ethylene carbonate from a crude ethylene carbonate composition, comprising the following steps: a) subjecting a crude composition comprising ethylene carbonate to at least one distillation step to obtain a pre-purified composition comprising at least 99.5% by weight of ethylene carbonate, and b) subjecting the pre-purified composition obtained in step a) to at least one melt crystallization step to obtain a purified ethylene carbonate composition wherein in step a) a bottom divided wall distillation column is used as a distillation column (if step a) comprises one distillation step) or as a first distillation column (if step a) comprises two or more distillation steps), and a bottom partition distillation column comprising a partition wall connected to the bottom of the bottom partition distillation column and extending upward from the bottom of the bottom partition distillation column by a portion of the height of the bottom partition distillation column, whereby a bottom section of the divided wall distillation column is subdivided into a first bottom sub-section and a second bottom sub-section as viewed from a cross-section of the divided wall distillation column.

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 invention relates to a process for purifying ethylene carbonate from a crude ethylene carbonate composition, said process comprising the steps of: a) subjecting a crude composition comprising ethylene carbonate to at least one distillation step to obtain a pre-purified composition comprising at least 99.5% by weight of ethylene carbonate; and b) subjecting the pre-purified composition obtained in step a) to at least one melt crystallization step to obtain a purified ethylene carbonate composition wherein the process is carried out in a plant comprising at least one distillation column, one vessel, at least one crystallizer and a feed line for a crude composition containing ethylene carbonate, wherein, if the apparatus comprises one distillation column, the distillation column, or, if the apparatus comprises two or more distillation columns, the first distillation column, comprising a top outlet line, a bottom outlet line and a side outlet line, wherein the at least one crystallizer comprises an inlet line for the pre-purification of the composition and an outlet line for the purification of the ethylene carbonate composition, and wherein the side outlet line of the distillation column is directly or indirectly connected to the inlet line of the at least one crystallizer for the pre-purification of the composition, wherein i) or the vessel is connected to the feed line for the crude composition containing ethylene carbonate and to an inlet line, where the inlet line is connected to a gas outlet of a first reboiler, where the first reboiler is further connected to a bottom outlet line of the distillation column, where the vessel further comprises an outlet line, where the outlet line is connected to a gas outlet of a second reboiler, where the first reboiler is further connected to a bottom outlet line of the distillation column. The outlet line leads to the inlet line of the distillation column via a second reboiler, in which a bottom fraction of the distillation column withdrawn from the distillation column via the bottom outlet line is partially evaporated in the first reboiler to obtain a gas fraction and a liquid fraction, or ii) the feed line for the crude composition containing ethylene carbonate is introduced into the distillation column, where the bottom outlet line of the distillation column leads to the vessel via a first reboiler, where the vessel comprises a gas outlet connected to the inlet line of the distillation column, where the bottom outlet line of the distillation column leads to the vessel via a second reboiler, where the gas outlet is connected to the inlet line of the distillation column. And the container comprises a liquid outlet which is connected with a pipeline leading into a second reboiler, the second reboiler comprises a gas outlet which is connected with an inlet pipeline of the distillation column, and the gas outlet is connected with a gas outlet of the distillation column. Wherein a bottom fraction of the distillation column withdrawn from the distillation column via the bottom outlet line is partially evaporated in the first reboiler, and wherein at least a portion of a gas fraction obtained in the first reboiler is recycled to the distillation column via the inlet line.

The utility model provides a pretreatment device for caprolactam refining raffinate, which is characterized in that a raffinate tank is communicated with the middle part of a solvent recovery tower through a raffinate tank discharge pump by a pipeline, the top of the solvent recovery tower is communicated with a solvent recovery tower top condenser and a solvent recovery tower reflux tank through pipelines, and the solvent recovery tower reflux pump is circularly communicated with the upper part of the solvent recovery tower; the bottom of the solvent recovery tower is communicated with the middle of the concentration tower through a solvent recovery tower kettle pump by a pipeline; the top of the concentration tower is circularly communicated with a concentration tower top condenser, a concentration tower reflux tank, a concentration tower reflux pump and the upper part of the concentration tower through pipelines; the bottom of the concentration tower is communicated with the upper part of the benzene extraction tower through a concentration tower kettle pump through a pipeline. The caprolactam refining raffinate recycling device solves the problem of high energy consumption caused by the fact that a large amount of caprolactam refining raffinate returns to an ammonium sulfate crystallization process, greatly reduces the circulation volume of the caprolactam refining raffinate, and greatly reduces accumulation of impurities in the device as the impurities and sewage are discharged to the sewage treatment device.

The utility model relates to the technical field of caprolactam, in particular to a device for reducing ammonium sulfate content in amide oil, which comprises a static mixer, the static mixer is provided with an amide oil feed pipe and a benzene feed pipe, a discharge port of the static mixer is connected to a decanter after passing through a decanter feed pump and a heat exchanger, the decanter is provided with a heavy phase discharge port and a light phase discharge port, and the heavy phase discharge port is connected with the light phase discharge port. A light-phase discharge port is conveyed to a cyclone membrane filter through a decanter discharge pump, a heavy-phase outlet of the cyclone membrane filter and a heavy-phase discharge port of the decanter are converged and connected to an ammonium sulfate mother liquor tank, and a light-phase outlet of the cyclone membrane filter is connected to a subsequent amide oil purification process. The device is provided with the links of benzene dissolving and crystallization, filtration, cooling, decanting, refiltration, cyclone separation, membrane filtration and the like, ammonium sulfate mother liquor and free ammonium sulfate particles in the amide oil are removed, the quality of the amide oil is improved, and the content of ammonium sulfate in the amide oil can be reduced to 0.5 wt% or below.

The present invention relates to a method for purifying ethylene carbonate from a crude ethylene carbonate composition comprising the steps of: a) subjecting a crude composition containing ethylene carbonate to at least one distillation step so as to obtain a pre-purified composition containing at least 99.5% by weight of ethylene carbonate and b) subjecting the pre-purified composition obtained in step a) to at least one melt crystallization step so as to obtain a purified ethylene carbonate composition, wherein in step a) as the distillation column, if step a) comprises one distillation step, or as the first distillation column, if step a) comprises two or more distillation steps, a bottom dividing-wall distillation column is used, which comprises a dividing wall being connected with and extending from the bottom of the bottom dividing-wall distillation column upwards over a part of the height of the bottom dividing-wall distillation column thereby subdividing the bottom section of the dividing-wall distillation column, seen in cross-section of the dividing-wall distillation column, into a first bottom subsection and into a second bottom subsection.

The present invention relates to a process for preparing ethylene oxide or propylene oxide comprising (b) reacting hydrogen with carbon oxides to form methanol, (c) converting the methanol from step (b) to ethene and / or propene, (d) reacting the ethene and / or propene from step (c) with oxygen or an oxidizing agent to form ethylene oxide and / or propylene oxide, wherein the carbon dioxide in step (b) is at least in part captured from industrial flue gases or from air or from ocean water or other natural waters or obtained from biological processes, for example from fermentation processes from waste or biomass, and / or wherein the hydrogen in step (b) is obtained at least in part by water splitting, the water splitting preferably using energy generated at least in part from non-fossil resources; a process for preparing ethanolamines, a process for preparing alkoxylated compounds, a process for making alkoxylated di-, oligo- and polyamines or alkoxylated polyethylenimine, a process for making alkoxylated polyethylenimine, a process for making surfactant, each process based on said process for preparing ethylene oxide or propylene oxide; polyethylenimines, ethanolamines, alkoxylated compounds, surfactants, alkoxylated di-, oligo- and polyamines, and alkoxylated polyethylenimines obtainable by the abovementioned processes; the use of the poly-ethylenimines, ethanolamines, alkoxylated compounds, surfactants, alkoxylated di-, oligo- and polyamines, and alkoxylated polyethylenimines; a composition being a laundry detergent, a cleaning composition or a fabric and home care product, containing at least alkoxylated di-, oligo- and polyamines or alkoxylated polyethylenimine, or a surfactant; the polyethylenimines, ethanolamines, alkoxylated, surfactants, alkoxylated di-, oligo- and polyamines, and alkoxylated polyethylenimines with a reduced amount of fossil-based hydrogen-content having thus an overall reduced cradle to gate product carbon footprint.

To provide a method for producing ε-caprolactam from a polyamide 6 resin composition, the method achieving both circulation utilization of fossil resources and reduction in global warming gas emissions, and therefore being green and energy-saving. The present invention is a method for producing ε-caprolactam, including bringing a resin composition (A) containing at least polyamide 6 and a polyamide 6 oligomer aqueous solution (C) heated to 290°C or higher and 350°C or lower into contact with each other, or bringing a resin composition (A) containing at least polyamide 6, a polyamide 6 oligomer aqueous solution (C) heated to 290°C or higher and 350°C or lower, and further water (B) heated to 290°C or higher and 350°C or lower into contact with each other.

The application provides a hole disc type liquid phase separator for cyclohexanone oxime liquid phase rearrangement product, which is arranged in the middle of a phase separation tower for liquid phase separation and comprises a liquid distribution disc and a liquid guide pipe, wherein the liquid guide pipe is composed of a support pipe and a phase separation structure which are connected with each other, and the liquid guide pipe is arranged perpendicularly to the liquid distribution disc. The phase separator can strengthen mass transfer and efficiently mix the liquid through the special liquid guide pipe. The space of each stage of the liquid distribution disc forms a uniform phase separation space, so that the purpose of multi-stage extraction is achieved, and the separation work such as single extraction, back extraction and ion exchange can be completed by a single extraction tower. Meanwhile, the phase separator can improve the mixing efficiency and mass transfer performance of the liquid, has the advantages of smaller occupied space, convenient installation and easy adjustment of the horizontal degree.

The invention provides a caprolactam purification method and application thereof. The purification method of caprolactam comprises the following steps: S1, carrying out alkali washing on a raw material benzene-hexane solution by using alkali liquor to obtain an alkali-washed benzene-hexane solution; s2, the benzene-hexane liquid obtained after alkali washing in the S1 is subjected to distillation and preliminary debenzolization, and benzene-hexane liquid obtained after preliminary debenzolization is obtained; s3, rectifying the benzene-hexane solution subjected to primary debenzolization obtained in the step S2 to obtain a caprolactam crude product rectified solution; and S4, recrystallizing the caprolactam crude product rectification liquid obtained in S3 to obtain caprolactam crystals. The caprolactam purification method is an efficient and green caprolactam rectification and crystallization purification method, can be used in a caprolactam-hexamethylenediamine process and can replace superior caprolactam, the cost is reduced, and the benefit is improved.

The invention discloses a preparation method of a catalyst suitable for caprolactam hydrofining, the caprolactam hydrofining catalyst prepared by the method, and a caprolactam hydrofining method adopting the catalyst. According to the present invention, after the surface treatment of the catalyst, the hydration reaction between the water molecules and the carrier (alumina) can be effectively inhibited so as to substantially improve the stability of the carrier pore structure in the water phase, such that the long-time storage of the catalyst under the deoxygenated water sealing condition is achieved, and the reduction state and deoxygenated water sealing supply form becomes possible.

The invention relates to the field of petrifaction, and discloses a green refining method of crude caprolactam, which comprises the following steps: S1, mixing crude caprolactam with a crystallization solvent, carrying out primary crystallization, carrying out solvent removal, heavy component removal and light component removal on a primary mother solution obtained by separation, mixing the recovered solvent and caprolactam with crude caprolactam, and recrystallizing; or removing the solvent from the primary mother liquor, recovering, concentrating, performing secondary crystallization, and separating to obtain secondary crystals and secondary mother liquor; carrying out solvent removal, heavy component removal and light component removal on the secondary mother liquor, mixing the recycled caprolactam with the primary mother liquor for secondary crystallization, separating to obtain secondary recycled crystals, mixing the secondary recycled crystals with secondary crystals and crude caprolactam, and then carrying out primary crystallization again; and S2, adsorption refining. According to the method disclosed by the invention, efficient and green refining of the crude caprolactam can be realized, the finally obtained caprolactam has high purity, low chroma and high yield, and the method has obvious advantages in production of high-end caprolactam products with extremely high chroma requirements.

The present invention provides a process and a plant for recovering purified E-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 e-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 present invention relates to a method for recovering epsilon-caprolactam from fishing nets comprising nylon 6. The invention provides a method and a plant for recovering purified epsilon-caprolactam from a fishing net comprising nylon 6, wherein the plant comprises a depolymerization section [B], a recovery section [C] and a purification section [D]. The invention also provides purified [epsilon]-caprolactam which has a particularly low product carbon footprint and is obtained by depolymerizing nylon 6 of a fishing net. In a second preferred embodiment, the purification of the distilled caprolactam is carried out by crystallization in the concentration process. The crystalline caprolactam produced by the concentration is generally sufficiently pure for direct use. After crystallization, it may be necessary to purify the mother liquor by recycling the mother liquor to the aqueous solution, for example, prior to extraction with alkylphenol. The mother liquor may be purified, for example, by distillation.

The invention discloses a method for recovering caprolactam by catalyzing hydrolysis of polyamide 6 by using a choline chloride-organic acid eutectic solvent, which comprises the following steps: preparing a eutectic solvent as a catalyst by using choline chloride as a hydrogen bond acceptor and organic acid as a hydrogen bond donor according to a molar ratio of 1: 2, mixing waste polyamide 6, the eutectic solvent and water, and heating to react, the polyamide 6 is efficiently depolymerized to generate the caprolactam monomer. After the reaction is finished, caprolactam is recovered through cooling, dilution with water and crystallization separation, and the eutectic solvent can be recycled. Compared with a traditional strong acid catalysis method, the method has the advantages that the reaction temperature is reduced by about 20-60 DEG C, the polyamide 6 degradation rate can reach 90% or above under the mild condition, and the caprolactam monomer yield reaches 70-85%. According to the method, the catalyst is low in toxicity, recyclable and non-corrosive, the product separation and purification process is simplified, and the method has the advantages of being low in energy consumption, high in efficiency and environmentally friendly and can be used for recycling waste nylon materials.

Methods of cleaning an N-methyl-2-pyrrolidone (NMP) purification and recovery system having an NMP-containing chemical waste stream, a separation tower fluidically coupled with the chemical waste stream, a reflux drum fluidically coupled with an upper section of the separation tower, a reboiler fluidically coupled with a lower section of the separation tower, and a purified NMP stream fluidically coupled with the reboiler. The methods include injecting a cleaning solution into the reflux drum and the reboiler with an amount of the cleaning solution sufficient to at least substantially fill the reflux drum and the reboiler, the cleaning solution comprising a solvent having a primary amine and a hydroxyl group, circulating the cleaning solution through at least the separation tower, the reflux drum, the reboiler for a period of time to solubilize foulants contained within the system, and draining the cleaning solution having foulants solubilized therein from the system.

The utility model discloses a recovery cleaning system for caprolactam in a filter in the technical field of filter cleaning, which comprises a filter, a flushing pipe, a collecting tank, a steam pipe and a nitrogen pipe, the collecting tank is a storage tank of a tank car, the filter is communicated with the collecting tank, and the flushing pipe, the steam pipe and the nitrogen pipe are all hermetically communicated with an exhaust pipe of the filter. The caprolactam in the filter is collected by using a tank truck, continuous inspection by personnel is not needed, and the transfer work of the caprolactam in the filter can be completed only by opening the exhaust pipe, the feeding pipe, the discharging pipe, the recycling pipe, the flushing pipe, the blending pipe, the steam pipe, the heating pipe and the nitrogen pipe according to steps; in the whole process, caprolactam does not make contact with the outside, caprolactam is convenient to transfer and store, manual carrying is not needed in the whole process, meanwhile, the filter and the filter element in the filter can be effectively and preliminarily cleaned in time, the filter element is prevented from being solidified and blocked, and convenience is brought to follow-up cleaning.

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

The utility model relates to a production device, belongs to the technical field of chemical production, and particularly relates to a caprolactam distillation coupling continuous production device which comprises a processing tank body, a top cover, a distillation device, a limiting pipeline, a discharge pipeline device, a solid-liquid separation tank and a driving mechanism. The solid-liquid separation tank is provided with a filtering hole and a bottom turning plate sealing assembly, and a rotary driving mechanism can drive the solid-liquid separation tank to rotate. The caprolactam solid-liquid separation device achieves the effects of efficient and automatic solid-liquid separation and smooth discharge of solid impurities, solves the problems that an existing caprolactam production device is low in solid-liquid separation efficiency, inconvenient to operate, difficult to maintain and insufficient in solution discharge, distillation continuity and device sealing performance, and powerfully improves production convenience and stability.

To provide a collection method capable of collecting ε-caprolactam and a polyamide 6 oligomer in high yield only by depolymerization using a small amount of water and solid-liquid separation with a small energy consumption. The present invention is a method for collecting ε-caprolactam and a polyamide 6 oligomer, including adding a resin composition (A) containing at least polyamide 6 and at least one of water (B) heated to 290°C or higher and 350°C or lower and a polyamide 6 oligomer aqueous solution (B1) heated to 290°C or higher and 350°C or lower to make contact with each other to obtain a reaction mixture (C) containing at least ε-caprolactam, a polyamide 6 oligomer, and water, and subjecting the reaction mixture (C) to a solid-liquid separation (I) in a temperature range not higher than a boiling point of water at an operation pressure to separate and collect a polyamide 6 oligomer in a solid phase, and an ε-caprolactam aqueous solution in a liquid phase.

To provide a method for collecting a fibrous filling material and ε-caprolactam with high purity only by solid-liquid separation from a polyamide 6 resin composition containing a fibrous filling material. The present invention is a method for collecting a fibrous filling material and ε-caprolactam, including adding a polyamide 6 resin composition (A) containing at least a fibrous filling material (D) and at least one of water (B) heated to 290°C or higher and 350°C or lower and a polyamide 6 oligomer aqueous solution (B1) heated to 290°C or higher and 350°C or lower to make contact with each other to obtain a mixture (C) containing at least the fibrous filling material (D), ε-caprolactam, a polyamide 6 oligomer, and the water (B), and collecting the fibrous filling material (D) and the ε-caprolactam from the mixture (C), wherein steps (a) to (c) below are performed in this order: (a) a step of preparing the mixture (C) by adding the polyamide 6 resin composition (A) containing the fibrous filling material (D) and at least one of the water (B) and the polyamide 6 oligomer aqueous solution (B1) to make contact with each other under a condition that a product of X and Y is 2,000 or less when a mass ratio of water to polyamide 6 or a mass ratio of water to a sum of polyamide 6 and the polyamide 6 oligomer is represented by X : 1 and a reaction temperature is represented by Y°C; (b) a step of subjecting the mixture (C) to a solid-liquid separation (I) in a temperature range not higher than a boiling point of water at an operation pressure; and (c) a step of washing a filter residue containing the fibrous filling material (D) obtained by the solid-liquid separation (I) with water having a temperature not higher than the boiling point of water at normal pressure to collect the fibrous filling material (D).

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

This invention relates to the field of chemical technology, and specifically discloses an extraction and separation system for caprolactam production. The system includes a circulating working fluid tank, a crude caprolactam oil tank, a heat exchanger, a transfer pump, and an extraction device. A first feed pipe connects the outlet at the bottom of the circulating working fluid tank to the inlet at the top of the crude caprolactam oil tank. A processing structure is installed on the first feed pipe. The circulating working fluid in the tank flows sequentially through the first feed pipe to a circulating working fluid precision filter, a static mixer, a circulating working fluid buffer and pressure stabilizing tank, and a circulating working fluid defoaming and fine filter, completing impurity filtration, homogenization, flow and pressure stabilization, and defoaming and fine filtration purification before being transported to the crude caprolactam oil tank for thorough mixing with the crude caprolactam oil. This solves the problems of impurities in the circulating working fluid, uneven mixing, fluctuations in transport pressure, and entrainment of air bubbles.