92 results about "Azeotropic distillation" patented technology

The invention belongs to the technical field of chemical production, and particularly relates to high-purity dimethyl carbonate and a preparation method thereof. The preparation method comprises the following steps: taking ethylene carbonate and methanol as raw materials, taking an alkali alcohol solution as a catalyst, carrying out transesterification in a rectifying tower to obtain dimethyl carbonate and methanol azeotrope, and extracting the azeotrope from the top of the rectifying tower; separating the dimethyl carbonate and methanol azeotrope by adopting pressurized azeotropic distillation to obtain a dimethyl carbonate crude product; and conveying the dimethyl carbonate crude product into a falling film crystallizer for continuous falling film crystallization, controlling the temperature of low-temperature chilled water in the falling film crystallizer to be-10 to 2 DEG C and the circulating material amount to be 3-5 times of the mass of the product required to be produced, and heating to melt the material to obtain the high-purity dimethyl carbonate product. According to the preparation method provided by the invention, rectification crude purification and continuous falling film crystallization processes are adopted, and dimethyl carbonate with the purity of 99.99% or above is obtained.

The invention relates to a synthesis process of p-chlorophenylboronic acid, which comprises the following steps: by taking tetrahydrofuran as a solvent and p-dichlorobenzene as an initial raw material, firstly preparing p-chlorophenylmagnesium chloride through Grignard reaction, then reacting the p-chlorophenylmagnesium chloride with boric acid ester in a microchannel reactor to obtain a p-chlorophenylboronic acid ester crude product, and then hydrolyzing, layering and carrying out oil-phase azeotropic distillation to obtain the p-chlorophenylboronic acid ester. And finally, recrystallizing by adopting a mixed system of an alcohol solvent and a benzene solvent to obtain p-chlorophenylboronic acid with the content of 98% or above. The synthetic process of the p-chlorophenylboronic acid is mild in reaction condition, simple and convenient to operate, low in cost, high in safety, high in product content and very suitable for being applied to industrial large-scale production.

The invention relates to a process for extracting alcohols from an initial mixture (1) comprising alcohols in aqueous phase, with:a distillative separation by an isopropanol-butanol distillation column (III) equipped at the top with a condenser (c3), intended for separating said mixture into a water-isopropanol azeotrope stream (6) at the top and into a water-butanol azeotrope stream (7) at the bottom,a distillative separation intended for separating the water-butanol azeotrope stream into water and butanol, by a hetero-azeotropic distillation system comprising at least one water-recovering water column (IV) and at least one butanol (9)-recovering butanol column (V) equipped with a reboiler (r5),such that a heat transfer is performed from the top water-isopropanol azeotrope stream (6) entering the condenser of the isopropanol-butanol distillation column (III), to the stream entering the reboiler of the butanol column (V).

The utility model relates to an MTO (Methanol To Olefins) concentrated water treatment device, which comprises a circulating liquid phase hydrogenation unit and a dehydration unit, aldehyde and ketone components in MTO concentrated water are converted into mixed alcohol through circulating liquid phase hydrogenation, and most of water in the mixed alcohol is removed through flash evaporation degassing, azeotropic distillation and zeolite membrane dehydration treatment. According to the MTO concentrated water treatment device, a mixed alcohol product with low water content (about 2wt%) and waste water with low alcohol content (less than 0.2 wt%) are obtained, the technical index of the obtained mixed alcohol product is higher than the national standard of alcohol-based liquid fuel GB16663-1996, and ethanol, isopropanol and 2-butanol products can be obtained through further separation. The additional value is also improved, and the purposes of improving the quality and improving the efficiency are achieved.

The application provides a preparation method of high-purity pyromellitic dianhydride, which is prepared from 2,3-dichloromaleic anhydride as raw material, and sequentially subjected to Diels-Alder cycloaddition reaction, elimination reaction and oxidation reaction to obtain high-purity pyromellitic acid, and then subjected to dehydration treatment to obtain high-purity pyromellitic dianhydride. In the preparation method, pyromellitic acid is used as a dehydration raw material to prepare anhydride, so that intermediate acid by-products are not easy to be generated, and the product purity is improved; the dehydration reaction is promoted by adopting azeotropic distillation and separation coupling, so that the reaction yield is improved; the preparation steps are few, the reaction process is simple, the reaction condition is mild, the raw materials are economically inexpensive and easy to obtain; the catalyst or the aid used in each step does not generate harmful substances, and is green and environment-friendly.

The invention discloses a knitted elastic composite sports suit and a preparation process thereof, and relates to the field of high polymer material modification and functional textiles, and the process comprises the following steps: firstly, thoroughly removing latent water in hollow silicon dioxide microspheres by using an azeotropic distillation technology, and regulating and controlling the density of active sites on the surfaces of the microspheres in cooperation with a double-effect silane system; then, grafting the modified microspheres to a polyurethane prepolymer main chain in situ under a low-temperature condition, and constructing an organic-inorganic covalent bonding network through a chain extension reaction; finally, modified fibers are prepared through dry spinning, and plaiting weave and moisture absorption and sweat releasing yarn are adopted for composite weaving. The technical problem that inorganic hollow filler is prone to gelation and spinning end breakage in polymerization is effectively solved, firm anchoring of functional particles in fibers is achieved, and the dynamic heat insulation stability, washing resistance and damp and hot comfort of sports suits are remarkably improved.

Provided is a method for producing purified isopropyl alcohol by dehydrating crude isopropyl alcohol containing water as an impurity, the method comprising: a phase separation step in which a mixed liquid of the crude isopropyl alcohol and an azeotropic agent is accommodated in a phase separation tank and phase-separated into an upper-phase liquid containing the azeotropic agent, water, and isopropyl alcohol and a lower-phase liquid containing water; and an azeotropic distillation step in which the upper-phase liquid is subjected to azeotropic distillation in an azeotropic distillation column, and a distillate containing an azeotropic mixture of the azeotropic agent and water and a bottom product containing isopropyl alcohol are extracted, wherein the distillate is supplied to the phase separation tank.

The invention provides a preparation method of an antioxidant TBHQ (tert-butylhydroquinone), which comprises the following steps: adding a certain amount of reducing agent into hydroquinone in the presence of an acid catalyst and a solvent, heating to a reaction temperature under the protection of nitrogen, maintaining for a certain time, and then introducing isobutene to carry out alkylation reaction; after the reaction is finished, separating the acid phase catalyst while hot, cooling, crystallizing and filtering an oil phase to obtain a crude product, adding a certain amount of water and a reducing agent into the crude product, carrying out azeotropic distillation under the protection of nitrogen to remove a residual solvent, filtering while hot to remove DTBHQ, cooling, crystallizing and filtering filtrate to obtain a semi-finished product, and recrystallizing the semi-finished product by using a solvent to obtain the DTBHQ. And finally, filtering and drying in vacuum to obtain a white finished product TBHQ. According to the preparation method disclosed by the invention, through the design of the technological process, the output of oxidation byproducts TBQ and DTBQ is greatly reduced, the product quality and yield are improved, three wastes are reduced, the cost is reduced, and the shelf life of the product can be prolonged.

The invention relates to the technical field of organic synthesis, and discloses a synthesis process of salicylaldehyde. The process sequentially comprises three core stages: firstly, performing mechanochemical ball milling pretreatment on phenol, a catalytic complexing agent and a molecular sieve drying agent in an inert atmosphere; then, transferring the pretreated mixture into a reactor containing a composite solvent of sulfolane and ionic liquid [BMIM] PF6, and dropwise adding a hexamethylenetetramine solution under programmed temperature control to perform formylation reaction; and finally, cooling the reaction liquid, filtering, hydrolyzing the filtrate by using a phosphoric acid aqueous solution with gradient concentration, and separating the product in real time through azeotropic distillation. According to the process, mechanical activation, composite solvent and programmed reaction are combined, the process is continuous, and the reaction efficiency and selectivity are improved.

The invention provides a device and method for producing engineering plastics through continuous polymerization of a rubber solution, and the device comprises a direct rubber solution conveying system which is provided with a polymerization kettle; the premixing unit comprises a dynamic mixer and a premixing kettle; the solvent recovery system comprises a devolatilization tower and an azeotropic rectification tower; wherein the polymerization kettle is directly connected with the premixing unit through a thermal insulation pipeline. According to the invention, the glue solution is directly used for polymerization production of ABS or HIPS, and the cyclohexane solvent is refined and recycled, so that the problems of high energy consumption, low efficiency, complex flow, environmental pollution and the like in the traditional process can be solved.

The invention discloses a production device and a production method of dimethyl adipate, and belongs to the technical field of organic chemical synthesis. According to the scheme, efficient conversion of part of adipic acid is realized in the pre-reactor, so that the reaction load of a subsequent catalytic distillation tower is reduced; cyclohexane is adopted as an azeotropic water-carrying agent in a catalytic distillation tower, water generated by reaction is removed in real time through azeotropic distillation, the equilibrium limitation of esterification reaction is broken, complete conversion of adipic acid is realized, and the reaction efficiency is remarkably improved. According to the method, methanol and cyclopentane are efficiently separated through the washing step, cyclic utilization of cyclopentane is achieved, and raw material consumption is greatly reduced; meanwhile, resource utilization of methanol is achieved through the methanol recovery system, and waste emission is reduced. The method can effectively reduce energy consumption and production cost, improves product quality, and solves the problems of easy catalyst deactivation, severe equipment corrosion, high three-waste treatment cost and the like in the prior art.

A process for converting a liquid feed based on hydroxypropanoic acid into bio-acrylic acid, comprising at least the following steps: a step of vaporization (a) of a liquid feed based on hydroxypropanoic acid (3), a step (b) of catalytic dehydration of the hydroxypropanoic acid-based gaseous stream (3) to form acrylic acid, and a specific recovery and purification sequence (steps c) to g)) for the bio-acrylic acid produced, to obtain a bio-acrylic acid purified in terms of propionic acid, said specific purification sequence being based in particular on a first step of azeotropic distillation of the aqueous acrylic acid effluent, making it possible to remove the propionic acid upstream of the transfer of the acrylic acid into the organic phase.

The invention discloses a method for recovering a tert-butyl acetate dealcoholization tower top material. Aiming at the problem that tertiary butanol and diisobutylene in a dealcoholization tower top material are unbalanced in proportion and cannot be directly recycled, the method comprises the following steps: adding a specific entrainer (such as methanol) into the material, and carrying out azeotropic distillation in a tertiary butanol recycling tower by utilizing the characteristic that the entrainer and diisobutylene form a lower-boiling-point azeotrope. An azeotrope of the entrainer and diisobutylene is extracted from the tower top, and an enriched tert-butyl alcohol material which can be directly recycled is obtained from the tower bottom. According to the method, only one rectifying tower unit is needed, the technological process is simple, the azeotrope which is difficult to treat through a traditional method is successfully separated, efficient recycling and cyclic utilization of the tert-butyl alcohol are achieved, it is not needed to purchase the tert-butyl alcohol to adjust the proportion, production raw material consumption and separation energy consumption of the tert-butyl acetate are remarkably reduced, and remarkable energy-saving and consumption-reducing benefits are achieved.

This invention discloses an azeotropic extraction apparatus and method for enhanced separation of a mixture of n-propanol, isopropanol, and acetonitrile using ionic liquids. The apparatus includes an azeotropic distillation column, a product separation column, an extractive distillation column, and two-stage adiabatic flash tanks. Part of the isopropanol from the top of the product separation column is refluxed to the azeotropic distillation column as an azeotropic agent. The ionic liquid from the bottom of the extractive distillation column is recovered via a first-stage flash tank and a second-stage flash tank. The vapor from the top of the second-stage flash tank is compressed by a compressor and then recycled back to the first-stage flash tank, forming a heat self-coupling. The control scheme includes temperature control via sensitive plates at both ends of the product separation column and cascade control of the extractant / azeotropic agent ratio. This invention operates at atmospheric pressure, avoiding investment in high-pressure equipment; the recovered ionic liquid purity reaches 99.9% and can be recycled long-term; and it can stably produce a product with a purity ≥99.9% even within a feed composition fluctuation range of ±30%.

The invention discloses a dehydration method of a raw material 1, 5-pentanediamine in a PDI synthesis process by a phosgenation method, which is characterized by comprising the following steps: firstly, uniformly mixing the raw material 1, 5-pentanediamine and a solvent chlorobenzene according to a mass ratio of 1: 3; secondly, according to the azeotropic distillation principle, water in the mixed material is slowly enriched at the tower top through reduced pressure distillation and tower top total reflux operation modes; thirdly, passing through a tower top oil-water two-phase dynamic separator, and slowly and continuously extracting the enriched water phase (upper layer) from an overflow port at the upper end of the dynamic separator; and then continuously extracting the qualified mixed material dehydrated in the tower kettle from the tower kettle. According to the method, the moisture content of the mixture of the dehydrated raw material 1, 5-pentamethylene diamine and the solvent chlorobenzene is less than or equal to 50ppm, the dehydration efficiency is high, and the operation cost is low. The technical index requirements of a PDI synthesis process by a phosgenation method are completely met.

The invention provides a process for inhibiting dioxane and unsulfonated substances in AES production, which comprises the following steps: (1) adding a composite inhibitor into a fatty alcohol-polyoxyethylene ether raw material for pretreatment, the composite inhibitor being composed of citric acid and EDTA (Ethylene Diamine Tetraacetic Acid); (2) carrying out sulfonation reaction on the pretreated raw materials by adopting sulfur trioxide; (3) neutralizing a sulfonated product; (4) sequentially carrying out water washing-azeotropic distillation and nanofiltration membrane separation on the neutralized product; and (5) drying to obtain a high-purity AES product. Synchronous removal of unsulfonated substances is realized, and an unexpected synergistic effect is generated through a composite inhibitor in a specific proportion.

Described is a process for preparing a catalyst precursor based on at least one transition metal belonging to groups 5 to 12, containing organic sulphur, in the form of sulfonate ions, and / or carboxylate ions, comprising the steps of - reacting an organic acid selected from a sulfonic acid, a carboxylic acid (of fossil or renewable origin), and their combination, with a source of said at least one transition metal, optionally in the presence of a reducing agent; - removing the water produced in the aforementioned reaction by azeotropic distillation, or by anhydrification with a drying agent, to obtain at least one carboxylate and / or sulfonate salt of said transition metal, with the condition that when the acid is only a carboxylic acid and the metal is only Mo, said Mo has an average oxidation state that varies from +6 to +4.

The invention discloses a device for industrial production of glycidol and a production method thereof, the top of a reaction kettle is provided with a liquid alkali solution continuous feeding hole and is connected with an azeotropic rectifying tower, the bottom of the reaction kettle is provided with a reaction liquid outlet, and the top of the azeotropic rectifying tower is provided with a gas phase outlet; a gas phase outlet is sequentially connected with a second condenser and a liquid-liquid layering device, an organic phase outlet of the liquid-liquid layering device is connected with a liquid distributor at the top of the azeotropic rectifying tower, and a water phase outlet of the liquid-liquid layering device is connected with a solvent recovery tower; an inlet of the centrifugal filtering device is connected with a reaction liquid outlet of the reaction kettle; a filtrate outlet is connected with an inlet of the wiped-film evaporation device; an organic phase outlet is formed in the top of the wiped-film evaporation device and connected with an inlet of the first condenser, and a heavy component discharge port is formed in the bottom of the wiped-film evaporation device; and an outlet of the first condenser is connected with a glycidyl rectification system. The method has the advantages of low cost, high safety coefficient, environmental protection, high product purity, high reaction yield and the like.

The invention relates to the technical field of chemical engineering, and particularly discloses an anhydrous organic peroxy acid production system and method.The anhydrous organic peroxy acid production system comprises a peroxidation reaction distiller, a first oil-water separator, an azeotropic distillation tower and a second oil-water separation and light component removal tower, and moisture is brought out of a reaction system through two times of azeotropy and two times of oil-water separation; and the solvent and the entrainer are respectively recovered through the azeotropic distillation tower and the light component removal tower, and the recovered materials can be recycled. According to the present invention, with the method, the hydrogen peroxide conversion rate and the organic peroxy acid selectivity are high, the prepared anhydrous organic peroxy acid has characteristics of excellent quality and water content of less than 0.01%, and the process has advantages of short reaction time, high raw material utilization rate, high heat energy utilization rate and good economy.

The invention provides a preparation method of tert-butylhydroquinone, which comprises the following steps: carrying out catalytic hydrogenation reduction reaction on hydroquinone and an isobutene alkylated oil phase to reduce TBQ and DTBQ into TBHQ and DTBHQ, adding water and a reducing agent into a crude product, carrying out azeotropic distillation under the protection of nitrogen to remove a residual solvent, and filtering to remove DTBHQ, thereby obtaining the tert-butylhydroquinone. Oxidation by-product impurities TBQ and DTBQ generated in the whole production process are basically distributed in the separated acid catalyst, the crude product mother liquor and the finished product mother liquor, the problem of enrichment of the oxidation by-product impurities is avoided, the quality and yield of the product are improved, and the method is suitable for industrial production. The three strands of materials can be used in a reaction unit or a crude product crystallization unit for next-batch preparation, harmful impurities TBQ and DTBQ are converted into a main product TBHQ and a by-product DTBHQ respectively, waste is turned into wealth, the problem of treatment of a large amount of VOC generated in the product drying process is avoided, and the method is environmentally friendly.

Provided is a production method by which the amount of a heating medium to be used in a process for producing water-absorbing resin particles can be reduced and the water-absorbing resin particles can be efficiently produced.　This method for producing water-absorbing resin particles comprises a polymerization step, a concentration step, and a drying step in this order. In the polymerization step, a reaction liquid comprising a polymer of a water-soluble, ethylenically unsaturated monomer, water, and a dispersion medium is produced by reversed-phase suspension polymerization. In the concentration step, water is removed by azeotropic distillation while the dispersion medium of the reaction liquid is being refluxed to the reaction liquid, thereby reducing the water content of the reaction liquid to produce a concentrate. In the drying step, the concentrate is dried while being exposed to air, thereby producing a dried object. The content of residual water in the concentrate to be dried in the drying step is 72 mass% or greater with respect to the total mass of the polymer contained in the concentrate.

This utility model relates to the field of PBT production and discloses an integrated device for a THF recovery system in the PBT production process. It includes an integrated distillation column, a cyclone separator, and a reboiler. The integrated distillation column has a feed inlet in the middle, and its interior has a vertically connected azeotropic distillation dehydration chamber and a de-heavy component chamber. The cyclone separator is installed inside the integrated distillation column, connected to the feed inlet, and located between the azeotropic distillation dehydration chamber and the de-heavy component chamber. The reboiler is connected to the de-heavy component chamber. The liquid phase separated by the cyclone separator flows to the de-heavy component chamber to remove heavy component impurities with boiling points higher than THF, while the gas phase flows to the azeotropic distillation dehydration chamber to separate water azeotropes from THF. This utility model integrates a dehydration column and a pre-distillation column into a single distillation column, reducing the space occupied by the dehydration column and increasing the utilization rate of the plant space. The dual separation steps of the cyclone separator and the distillation column improve the dehydration and de-heavy component effects, reducing energy consumption.

The invention provides a synthesis method of mercaptopropyltrimethoxysilane, which comprises the following steps: dissolving industrial sodium hydrosulfide in a composite solvent, separating water through azeotropic distillation, reacting the separated and dewatered industrial sodium hydrosulfide-composite solvent solution with chloropropyltrimethoxysilane to obtain a reaction product, and carrying out heat preservation on the reaction product; carrying out cooling, filter pressing, rectification and separation on the reaction product subjected to heat preservation to obtain mercaptopropyltrimethoxysilane; the composite solvent comprises a first type of solvent and a second type of solvent, the first type of solvent is a non-water-soluble solvent, and the second type of solvent is a water-soluble solvent. According to the method, after water in sodium hydrosulfide is removed through azeotropic distillation, chloropropyltrimethoxysilane is added for full reaction, so that reaction products are prevented from being reacted with water, and after the reaction is completed, high-purity mercaptopropyltrimethoxysilane is obtained through cooling, filter pressing and distillation separation.

The invention discloses a membrane permeation-pressurized rectification coupling process of a diisopropylamine-isopropanol ternary water-containing system, which comprises the following steps: primarily separating by an azeotropic rectification tower to obtain a diisopropylamine-isopropanol-water homogeneous ternary mixture at the tower top, and cooling by a cooler to obtain a ternary mixture; conveying to a membrane dehydration assembly to selectively remove moisture; and the dehydrated diisopropylamine-isopropanol mixture enters a pressurized rectifying tower, so that high-purity recovery of diisopropylamine and isopropanol is realized. The process does not need to introduce a third component, equipment is simple, the recovery purity is high, meanwhile, chemical pollution is avoided, and the environmental protection requirement is met.

A system for separating alkane-water azeotropic distillation of alcohol-keto acid esters comprises a small distillation tower concentrically assembled at the bottom of a first distillation tower, a first circulation line having an upstream end connected to the bottom of the first distillation tower and a downstream end connected to a distributor located at the top of the small distillation tower, a second circulation line having an upstream end connected to the bottom of the second distillation tower and a downstream end connected to the lower sidewall of the second distillation tower, a first reflux line having an upstream end connected to the top of the first distillation tower via a condenser and a downstream end connected to the reflux port of the first distillation tower, a second reflux line having an upstream end connected to the top of the second distillation tower via a condenser and a downstream end connected to the feed port of the second distillation tower, a second discharge line being provided at the bottom of the small distillation tower for feeding the second distillation tower, and a second valve being provided. The present invention has a simple structure, low maintenance cost, can effectively reduce energy consumption in separating alkane-ketone-water azeotropes, and has high separation purity.

The utility model discloses a system for separating n-butyl alcohol from water by using a rectification-membrane separation integrated process. The system comprises an azeotropic rectification tower, a reboiler, a NaA molecular sieve pervaporation membrane device, a reflux pump and an n-butyl alcohol extraction pump, a feeding pipeline is arranged in the middle of the azeotropic rectifying tower, a gas phase outlet pipe is arranged at the top of the azeotropic rectifying tower, and a discharging pipe is arranged at the bottom of the azeotropic rectifying tower; the NaA molecular sieve pervaporation membrane device is arranged at the tower top, azeotrope of n-butanol and water can be effectively separated, a traditional azeotropic distillation process and a novel molecular sieve membrane dehydration separation technology are combined, azeotropic limitation of the n-butanol-water mixture is effectively broken through, efficient recovery of the two substances is achieved, and the production cost is reduced. The system is energy-saving, environment-friendly, high in recovery rate, low in investment and suitable for industrial application and popularization.

The invention belongs to the technical field of chemical synthesis processes, and particularly relates to a continuous batching method for preparing polyphenylene sulfide, and the method comprises the specific steps of reactive monomer batching, azeotropic agent mixing, azeotropic distillation, azeotropic agent recovery and product delivery. The method has the advantages that the method is simple in process, high in production efficiency, stable in dehydration product quality and simple in process control, and a binary azeotropic system is formed by the aid of the method and a water phase, so that process energy consumption and NMP (N-methyl pyrrolidone) loss are reduced, batches have good uniformity, and continuous burdening is realized. The method has the advantages of simple procedures, high production efficiency, stable dehydration product quality and simplicity in process control.

The invention belongs to the technical field of glyceryl triacetate production and purification, and discloses a dehydration and deacidification device for glyceryl triacetate production, which comprises a treatment cylinder, a negative pressure pump fixed on the outer side of the treatment cylinder, and a condensation part arranged in the treatment cylinder, the condensation part comprises a cooling storage cavity, an isolation conduction plate, a condensation pipe and a through hole formed in the isolation conduction plate. According to the invention, depressurization distillation and azeotropic distillation are respectively adopted before and after, acetic acid removal and moisture removal are respectively completed, and directional deflection of the distribution condensation collection assembly is matched, so that products in two distillation treatment processes are successfully and effectively separated, independent separation and export of acetic acid removal are realized, and directional separation and collection of subsequent moisture are realized; the condition that acetic acid and water are mixed together after being separated is avoided, independent separation and export treatment is achieved, rapid export and separation are achieved through cooperation of the distribution condensation collection assembly and the distribution export assembly after separation, additional drainage operation is avoided, and the separation effect is good.

The invention belongs to the technical field of chemical separation, and particularly relates to a device and a method for separating and purifying tetrahydrofuran and n-butyl alcohol from gamma-butyrolactone production industrial waste liquid. The device comprises a pre-separation tower, an n-butyl alcohol refining tower, a water treatment tower, a butanone removal tower, a tetrahydrofuran extraction tower and a solvent recovery tower, the quality purity of tetrahydrofuran separated by adopting the device can reach 99.95% or above, the recovery rate can reach 94.3% or above, the quality purity of n-butyl alcohol can reach 99.5% or above, and the recovery rate can reach 99% or above. According to the method, a separation method combining extractive distillation and heterogeneous azeotropic distillation is adopted, an ionic liquid 1-butyl-3-methylimidazole acetate is used as an extraction agent for extractive distillation separation of a tetrahydrofuran-water mixture, and a mixture of n-butanol and water is separated through heterogeneous azeotropic distillation without adding an entrainer. The process provided by the invention plays an important role in environmental protection and clean production, and can realize low-energy-consumption, clean and efficient separation of the azeotropic system.

The application provides a separation and purification system and process for energy coupling variable pressure refining of butylamine, which comprises atmospheric azeotropic distillation of butylamine raw material containing water to separate a first distillate and a first still residue; pressure azeotropic distillation of the first distillate to separate a second distillate and a first target product; refluxing of the second distillate and atmospheric azeotropic distillation with the first still residue and butylamine raw material containing water to separate a third distillate and a third still residue, wherein the third still residue comprises n-butylamine, di-n-butylamine and tri-n-butylamine; distillation of the third still residue to separate a second target product, a third target product and a fourth target product; and the reaction conditions are selected from at least one of the following: a reflux ratio of 1.6-3.0 and a temperature of 43-63 DEG C for the atmospheric azeotropic distillation; and a reflux amount of 535 kg / h-2470 kg / h for the second distillate. The system and process of the application can greatly reduce equipment and operation costs on the basis of obtaining high-purity n-butylamine, di-n-butylamine and tri-n-butylamine products.