117results about "Extractive distillation" patented technology

A separation system for separating constituents from a solution by utilizing a carrier gas and a separation method thereof are disclosed. The separation system includes an evaporator, a solution distribution unit connected to the evaporator for distributing the solution into the evaporator, and a gas distribution unit connected to the evaporator for distributing the carrier gas into the evaporator. The solution is countercurrent to the carrier gas and upon contact, at least one constituent of the solution is vaporized and separated from the solution.

The invention relates to a method for separating an n-propyl formate-n-propyl alcohol-water mixture by liquid-liquid phase separation coupling extractive distillation, which comprises the following steps of: dividing a raw material into a water phase and an organic phase by using a phase splitter based on the heterogeneous characteristic of an azeotropic system, and carrying out four-tower operation on a rectifying tower (C1), a rectifying tower (C2), a rectifying tower (C3) and a rectifying tower (C4) to obtain an n-propyl formate-n-propyl alcohol-water mixture. The efficient separation of the n-propyl formate-n-propyl alcohol-water mixture is realized. After separation, the molar fraction of n-propyl formate is greater than 99.99%, the molar fraction of n-propyl alcohol is greater than 99.99%, and the molar fraction of water is greater than 99.99%. The method provided by the invention realizes high-efficiency and low-energy-consumption separation of the n-propyl formate-n-propanol-water azeotropic mixture, and has economic benefits and environmental friendliness.

The invention discloses a synthesis process of tungsten hexafluoride, and relates to the technical field of special gas synthesis. The process comprises the following steps: mixing ammonium fluoride and hydrofluoric acid to prepare an activation solution, carrying out ultrasonic activation treatment on tungsten powder to obtain pretreated tungsten powder, and reacting the pretreated tungsten powder with fluorine gas at a certain temperature and pressure to prepare a liquefied crude product tungsten hexafluoride; the preparation method comprises the following steps: by taking aluminum sec-butoxide and the like as raw materials, carrying out sol-gel and ethanol supercritical drying and calcining to prepare highly porous activated aluminum oxide; gasifying the crude tungsten hexafluoride, adsorbing with activated aluminum oxide, and rectifying to obtain purified tungsten hexafluoride liquid; and finally, dissolving in liquid sulfur dioxide, treating under illumination with the wavelength of 395nm, and carrying out distillation separation to obtain high-purity tungsten hexafluoride. According to the method, the activation pretreatment is combined with multi-stage purification, so that the purity and the synthesis efficiency of tungsten hexafluoride are remarkably improved.

This propylene oxide purification device is provided with a line LX and / or a line LY. The line LX is configured so as to supply a liquid in a first drum D10 to a first distillation column T10 via a feed inlet 10i of the first distillation column T10, and the line LY is configured so as to supply a liquid in a third drum D30 to the first distillation column T10 via the feed inlet 10i of the first distillation column T10.

A production system, production method and application of general-purpose high-purity chemicals are disclosed. The production system includes a raw material tank, and an adsorption system, a crystallizer, a first light-impurity removal tower, a first heavy-impurity removal tower, a second light-impurity removal tower, a motorized tower, a second heavy-impurity removal tower, a vapor permeation device, a membrane separation system and a filling system connected with the raw material tank in sequence. The high-purity chemicals produced by the above system have high purity and excellent quality. Compared with the prior art, the system and method designed by the present disclosure have more pertinence, integrity, progressiveness, energy-saving, precision, high safety coefficient and great industrial promotion value. And the products produced are of excellent quality, which can meet the standards applied to the manufacturing of integrated circuit electronic components and meet the high-end needs of the semiconductor industry market.

The utility model relates to the technical field of chemical separation, in particular to a dual-purpose extractive distillation tower for separating acetic acid from water, which comprises an extraction tower, a condenser I, a condenser II and a reboiler, an extraction chamber, a distillation chamber and a circulation chamber are arranged in the extraction tower, the distillation chamber and the extraction chamber are symmetrically arranged, and the circulation chamber is positioned below the distillation chamber and the extraction chamber. The first condenser and the second condenser are located above the extraction tower, the first condenser is communicated with the extraction chamber, the second condenser is communicated with the rectification chamber, and by integrating the two functions of extraction and rectification, the tower achieves effective separation of acetic acid and water. The layered contact design ensures that the acetic acid raw material and the composite extraction agent are in full contact but not directly mixed between filler layers, the mass and heat transfer process is optimized, the extraction agent can be recycled after being treated by the rectification chamber, and the resource waste is remarkably reduced. And due to the recycling design, the operation cost is reduced, and the consumption of the extracting agent is reduced.

The present invention relates to a Venturi separator, characterized in that the Venturi separator comprises a Venturi tube and a liquid-phase collector tube which encloses at least a part of the structure of the Venturi tube, wherein the Venturi tube comprises the following sequentially connected sections: an optional constant-diameter section, a reduced-diameter section, a neck and an expanded-diameter section, and the Venturi separator has a gas-phase inlet, a liquid-phase inlet, a liquid-phase outlet and a gas-phase outlet, wherein an opening is provided on a side wall of the expanded-diameter section of the Venturi tube or at the end of the expanded-diameter section, the opening leading to the liquid-phase collector tube so that a liquid phase can leave the Venturi tube and enter the liquid-phase collector tube under centrifugal force.The present invention also relates to the use of the Venturi separator in chemical processes.

The invention relates to the technical field of chemical separation and extractive distillation, and discloses a method for separating n-hexane and methylcyclopentane by an organic Rankine cycle assisted extractive distillation dividing wall column. The device comprises two parts, one part is a cyclohexane separation tower, and the other part is an organic Rankine cycle auxiliary extractive distillation dividing wall tower. The technical innovation lies in that the original double-tower extractive distillation is coupled into a single dividing wall tower, the separation of a multi-component mixture can be realized, and meanwhile, the organic Rankine cycle is introduced from the perspective of power generation to realize the recovery of sensible heat in the tower kettle material flow of the main tower and power generation. According to the device, on one hand, the extractive distillation dividing wall column is adopted to replace the original double-column extractive distillation, so that the backmixing problem among components can be reduced, and the energy consumption and the investment cost can be reduced; and on the other hand, organic Rankine cycle is adopted to convert heat energy into electric energy, effective utilization of waste heat is achieved, and wide application prospects are achieved.

The invention belongs to the technical field of separation and purification, and particularly relates to a method for separating a methanol-dimethyl carbonate azeotrope system, which adopts a system for separating a methanol-dimethyl carbonate azeotrope and adopts a eutectic solvent as an extracting agent for extractive distillation. The hydrogen bond acceptor of the deep-eutectic solvent is choline chloride, and the hydrogen bond donor of the deep-eutectic solvent is malonic acid or urea. According to the method, the choline chloride deep eutectic solvent which is lower in cost, simpler and more convenient to prepare and more environmentally friendly is selected as the extracting agent, systematic process parameter optimization and equipment configuration design are carried out according to the high-viscosity characteristic of the choline chloride deep eutectic solvent, and stable, efficient and long-period operation of the high-viscosity green solvent in the continuous extractive distillation process is successfully achieved; the target of separating the methanol and the dimethyl carbonate from the binary mixture is achieved, the final yield of the methanol and the dimethyl carbonate can reach 99% or above, the product purity can reach 99.5% or above, and compared with a traditional solvent separation method, the energy consumption is greatly reduced, the equipment cost is saved, and the method is suitable for industrial production. The strict standard of the high-end chemical industry and the fine chemical industry on the raw material purity can be reached.

The invention discloses a chloroform / ethanol / water system extraction variable-pressure rectification process for comprehensive utilization of latent and sensible heat, which realizes efficient and comprehensive utilization of energy through three-tower operation of an extraction reduced-pressure rectification tower T1, an extraction rectification tower T2 and a solvent recovery reduced-pressure rectification tower T3. The tower top steam of the extractive distillation tower T2 is used for heating the tower bottom liquid of the extractive decompression distillation tower T1 to vaporize the tower bottom liquid, and meanwhile, the tower top steam of the solvent recovery decompression distillation tower T3 is used for carrying out heat exchange on part of the liquid phase of the middle plate of the extractive decompression distillation tower T1; the problem that the tower top temperature of the solvent recovery vacuum distillation tower T3 is between the tower top temperature of the extraction vacuum distillation tower T1 and the tower kettle temperature, and traditional heat integration cannot be achieved is solved, and latent heat utilization is achieved. In addition, the tower kettle liquid of the solvent recovery vacuum distillation tower T3 is used for heating the tower kettle liquid of the extraction distillation tower T2 and the extraction vacuum distillation tower T1, and sensible heat utilization is achieved. According to the process, heat energy is fully utilized, energy consumption is reduced, the purity and yield of chloroform, ethanol and water are improved, and the equipment cost is reduced. And the adopted extracting agent is small in dosage, relatively weak in volatility, small in loss, easy to recover and environment-friendly.

The invention belongs to the field of sugar industry, and discloses a method for enriching and separating sugarcane flavor substances. A co-processing method of sugarcane juice acid adjustment, heating, vegetable tannin coagulation, plate frame filtration, secondary heating, high-temperature evaporation, condensation, subcritical extraction and distillation is mainly adopted, filtered juice subjected to existing plate frame filtration treatment is high in quality, the water content of a filter cake is low, and the extraction, enrichment and purification processes of sugarcane flavor substances are green production processes. The method has the advantages that the method is simple in operation, the influence on subsequent processing of the sugar juice is small, the comprehensive utilization value of the obtained filter mud, deodorized water and other byproducts is high, the sugarcane flavor substance enrichment and separation system has the characteristics of compact and advanced equipment, high efficiency and the like, products are diversified, the value of the byproducts is high, and the comprehensive economic benefit and social benefit are very remarkable.

The invention belongs to the field of chemical engineering, and relates to a high-water-content low-carbon alcohol separation system and a process method thereof, the system comprises a first crude separation tower, a second crude separation tower, a stripping tower, a regeneration tower, a methanol tower, an ethanol tower, an isopropanol tower, an n-propanol tower and an n-butanol tower, each tower is provided with a condenser and a reboiler, and a mixed alcohol raw material is subjected to a crude dehydration and extractive distillation dehydration mode. Coarse dehydration, namely dehydration by a coarse separation tower and a stripping tower, can remove about two thirds of water with lower energy consumption; compared with an azeotropic distillation dehydration process, the extractive distillation dehydration process is lower in energy consumption and higher in efficiency, a heat exchange network of the separation process is optimized, and energy consumption is greatly reduced.

This disclosure provides a method for efficiently purifying difluoromethane (HFC-32).Specifically, the present disclosure provides a method for producing a purified HFC-32, the method including:an extractive distillation step of contacting a composition containing difluoromethane (HFC-32) and a component X with a solvent A to obtain a composition containing a reduced component X from the composition,wherein the component X is at least one selected from the group consisting of pentafluoroethane (HFC-125), 1, 1, 1-trifluoroethane (HFC-143a), and dichlorodifluoromethane (CFC-12), andwherein the solvent A is at least one of an amine and a fluorinated ether.

The invention belongs to the technical field of petrochemical industry, and discloses an energy-saving method and device for refining 1-butene from etherified C4. The method comprises the following steps: carrying out selective hydrogenation on etherified C4 to remove butadiene, feeding the etherified C4 into a pretreatment tower adopting a heat pump technology for primary separation, and extracting a fraction rich in 1-butene from a side line; the fraction enters an extractive distillation tower, and efficient separation of 1-butene and butane is achieved by adding an extractant; the rich solution containing 1-butene is separated by a product tower to obtain a high-purity 1-butene product; and the high-temperature lean solvent extracted from the bottom of the product tower sequentially flows through a plurality of heat exchange devices such as an intermediate reboiler of the extractive distillation tower, a second reboiler of the pretreatment tower, a raw material preheater and the like, and is recycled after waste heat is fully recovered. The invention also provides an alternative scheme for additionally arranging the solvent recovery tower and a corresponding device. The process flow is reasonable, the energy integration level is high, the consumption of steam and cooling water can be greatly reduced, and the obvious energy-saving effect and economical efficiency are achieved.

The invention relates to a method and installation for recycling a mixture comprising at least one fluorinated fluid, the mixture comprising one or more fluorinated chemical components and one or more contaminants selected from one or more hydrocarbons and / or one or more fluorinated contaminants, including a double membrane filtration step to reduce the contaminant content of the mixture. Figure for the abstract: Figure 1

The utility model discloses a solid-liquid extraction device in the technical field of extraction. The device comprises a condenser pipe, a rectifying tower, an extraction cavity and a solvent boiling bottle which are sequentially connected and communicated from top to bottom, and a plurality of layers of gas-liquid distribution elements for expanding the superficial area of gas-liquid exchange are arranged in the rectifying tower. The extraction device disclosed by the utility model has the advantages that the extraction device and the rectifying tower can exchange heat with reflux liquid through rising steam, the reflux liquid can be continuously heated to be close to a boiling point, the temperature consistency of the reflux liquid flowing back to the extraction cavity can be greatly guaranteed, the temperature in the extraction cavity is increased, and the extraction efficiency is greatly improved.

The utility model discloses rectification equipment for hexane extraction. The rectification equipment comprises a base, a shell mounted at the top end of the base, an inlet mounted at the top end of the shell, a recovery mechanism mounted at the top end of one side of the shell, a filter screen mounted on one side of a discharge pipe, a discharge pump mounted on one side of the discharge pipe, and a flange mounted on one side of the discharge pipe. The discharging pump is installed on one side of the discharging pipe, suction force can be generated when the discharging pump works, hot air in the shell can be sucked out when the discharging pump works, then the hot air can be sucked out through the discharging pipe, the discharging pipe can be connected with other pipelines through the flange plate, the hot air passing through the discharging pipe can be filtered through the filter screen, and the filtering effect is good. According to the rectifying equipment for hexane extraction, dust is prevented from entering the discharging pipe, hot air can enter different devices through the discharging pipe and other pipelines, the hot air can be recycled, the devices are more energy-saving and environment-friendly, and therefore the purpose that the rectifying equipment for hexane extraction can conveniently recycle heat is achieved.

A system is provided for the thermal separation of a process liquid using an immiscible liquid, in accordance with some embodiments. In some embodiments, the system comprises a precipitate extraction evaporator configured to receive the process liquid and immiscible liquid within an enclosed vessel. In some embodiments, the process liquid is injected into the immiscible liquid and undergoes phase change to form steam. In some embodiments, the steam is condensed by a condenser positioned above the immiscible liquid. In some embodiments, the condensed steam is collected and discharged as fresh water. In some embodiments, precipitate formed in the immiscible liquid is directed to a precipitate collection area. In some embodiments, a conveyor is configured to remove the precipitate from the enclosed vessel. In some embodiments, the system is integrated with one or more desalination and / or heat recovery subsystems.

The utility model relates to a device for refining acetophenone and alpha-phenethyl alcohol, which comprises a first rectifying tower provided with a first inlet, a first outlet, a first discharge port and an extractant inlet; the second rectifying tower is provided with a second inlet, a second outlet and a second discharge port, and the second inlet is communicated with the first discharge port; the third rectifying tower is provided with a third reboiler which is provided with a third inlet, a third outlet and a third discharge port, the third outlet is formed in the top of the third rectifying tower, the third discharge port is formed in the bottom of the third rectifying tower, and the third reboiler of the third rectifying tower is communicated with the second outlet; the material flowing out of the second outlet is condensed by a third reboiler and then is branched into two paths, one path flows back to the upper part of the second rectifying tower, and the other path is communicated with a third inlet; the cooler is provided with a material inlet and a liquid outlet, the material inlet is communicated with the third outlet, and the liquid outlet is used for discharging alpha-phenethyl alcohol. The energy consumption is reduced.

The utility model discloses a mother liquor recycling device for bronopol production, and relates to the technical field of bronopol production, an inlet of a reduced pressure distillation kettle is communicated with a mother liquor tank through a pipeline, an outlet of the reduced pressure distillation kettle is communicated with a rectifying tower through a pipeline, and a top outlet of the rectifying tower is communicated with a first condenser through a pipeline; and an outlet of the first condenser is communicated with a bronopol tank through a pipeline. The reduced pressure distillation kettle is used for distilling the mother liquor under a reduced pressure condition, so that the boiling point of each component in the mother liquor is reduced, the energy consumption is reduced, and the decomposition or side reaction of bronopol and other components at high temperature is avoided. The mother liquor subjected to primary concentration and separation through reduced pressure distillation enters a rectifying tower, bronopol and other impurities with similar boiling points are further separated through rectification, and primary purification is achieved. The bronopol steam at the top of the tower is condensed by the first condenser and then is collected to the bronopol tank, so that the bronopol product with higher purity is obtained, and the key step of recovering bronopol from the mother liquor is coherently realized in the whole process.

The invention discloses a heat integration heat pump assisted extractive distillation separation methanol ether water azeotrope, which is characterized in that a methanol-methyl tert-amyl ether-water mixed solution is separated through three-tower operation of an extraction reduced pressure distillation tower T1, an extraction distillation tower T2 and a solvent recovery reduced pressure distillation tower T3. Tower top steam of the extractive distillation tower T2 is used for exchanging heat for part of liquid phase of a middle plate of the extractive decompression distillation tower T1, the problem that traditional heat integration cannot be achieved due to the fact that the tower top temperature of the extractive distillation tower T2 is between the tower top temperature of the extractive decompression distillation tower T1 and the tower kettle temperature is solved, and a novel heat integration strengthening process is developed. According to the process, heat energy is fully utilized, and energy consumption and equipment cost are reduced. And the adopted extracting agent dimethyl sulfoxide is small in dosage, relatively weak in volatility, small in extracting agent loss, easy to recover and environment-friendly. The purity of separated methanol is greater than 99.9%, the yield is greater than 99.9%, the purity of methyl tert-amyl ether is greater than 99.9%, the yield is greater than 99.9%, the purity of water is greater than 99.9%, the yield is greater than 99.9%, and the purity of mixed extraction agents dimethyl sulfoxide and ethylene glycol is greater than 99.9%, and the yield is greater than 99.9%.

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.

Systems and processes for the production of a high purity isobutylene stream, a high purity isooctene stream or for the co-production of a high purity isobutylene and a high purity isooctene. The systems and processes advantageously process mixed C4 hydrocarbon streams via etherification, back cracking, isomerization, and / or dimerization, along with various separation systems, to produce the desired high purity streams.

A propylene oxide separation system comprising a heavies distillation column configured to receive a crude propylene oxide stream and discharge a heavies purge bottoms comprising at least one impurity selected from acetone, methanol, aldehydes, aldehyde derivatives, water, heavy hydrocarbons comprising C5+, or combinations thereof, and discharge a heavies distillation column overhead stream comprising a majority of the propylene oxide entering with the crude propylene oxide stream, and a first extractive distillation column configured to receive the heavies distillation column overhead stream and a first extraction solvent stream comprising a hydrocarbon solvent, and discharge a lights purge overhead comprising at least one impurity selected from aldehydes (e.g., acetaldehyde, formaldehyde, etc.) methyl formate, methanol, water, C3 hydrocarbons, C4 hydrocarbons, or combinations thereof, and discharge a rich solvent bottoms stream comprising a majority of the propylene oxide entering via the heavies distillation column overhead stream. A propylene oxide purification method is also provided.

The disclosure provides a method of purifying a linear alpha olefin product that includes feeding a linear alpha olefin feed stream comprising the linear alpha olefin product and ethylene into a feed stage of a distillation column, the distillation column having a plurality of stacked stages positioned between an overhead outlet and a bottoms reboiler including a stripping section and a rectifying section; feeding an aliphatic paraffin hydrocarbon solvent to the rectifying section of the distillation column to absorb linear alpha olefin; adding heat to at least one of said plurality of stacked stages in the stripping section of the distillation column between the feed stage and the bottoms reboiler; withdrawing an overhead stream comprising ethylene from the overhead outlet; and withdrawing a bottoms stream from the distillation column comprising the linear alpha olefin product.

The application provides a process and system for recovering DMT and DMC from polyester-containing blended fabric, comprising: under the action of an ionic catalyst, a depolymerization reaction of polyester-containing blended fabric and DMC; after the reaction, the material is subjected to solid-liquid separation and first crystallization to obtain a crystallization mother liquor and a DMT crude product, the DMT crude product is subjected to dissolution, removal of solid impurities and recrystallization to obtain a DMT pure product; the crystallization mother liquor is subjected to light removal, reaction rectification and extractive rectification to obtain a second DMC fraction, which is recycled to the depolymerization reaction; a methanol fraction, which is recycled to the reaction rectification; and an extractant fraction, which is recycled to the extractive rectification. The operation conditions are mild, the material and energy are closely coupled between units, a multiple circulation network of DMC, methanol, extractant and catalyst is formed, the overall resource utilization rate is high, the degree of greenness is high, and an economic and feasible technical scheme which is easy to industrialize is provided for chemical recycling of waste polyester textiles.

A system and method separate a process fluid stream into a liquid phase carbon dioxide stream and a carbon dioxide depleted stream containing a remaining light gas. The systems and methods use a drying heat exchanger to contact a process fluid stream with a dryer contact liquid to remove moisture from the process fluid stream. The gaseous process fluid stream is separated from the wet dryer contact liquid stream and directed to an extraction heat exchanger where it is contacted with an extraction contact liquid such that carbon dioxide is removed from the process fluid stream while forming a processed process fluid stream and a carbon dioxide enriched extraction contact liquid stream.

The present application relates to an extractive distillation column comprising, from bottom to top, a tray section, a movable section and a packing section; the packing section comprises gas-liquid contact mass transfer elements referred to as first packing; the movable section comprises gas-liquid contact mass transfer elements referred to as second packing, or comprises a packing-tray composite which is a composite of gas-liquid contact mass transfer elements referred to as third packing and gas-liquid contact mass transfer elements referred to as first stereo-spray tray; the tray section comprises gas-liquid contact mass transfer elements referred to as second stereo-spray tray, wherein the extractive distillation column further comprises an extractant inlet, a feedstock inlet, a top vapor outlet, a bottom liquid outlet and optionally a side inlet, and the packing section is located above the extractant inlet; the movable section is located between the extractant inlet and the feedstock inlet; the tray section is located below the feedstock inlet. The present application also relates to an extractive distillation system comprising the above extractive distillation column and an extractive distillation method using the extractive distillation system.

A process apparatus for a distillation process comprises a distillation column (100) that processes material (104) of a mixture of water, at least acetic acid and formic acid and furfural, furfural being used as a former of azeotrope and an extractant in the mixture. A flowing material channel (102) is located between a lower section (106) of the column (100) and an upper section (108) of the column (100), the flowing material channel (102) comprising a solid material remover (110). A feed arrangement (112) is connected with the flowing material channel (102) between the lower section of the column (100) and the solid material remover (110). The flowing material channel (102) receives a stream of the processed material (104) from the lower section (106) of the column (100), a stream of precipitant from the feed arrangement (112), precipitation effect of the precipitant being based on water, and directs the mixture of the streams of precipitant and processed material (104) to the solid material remover (110), which removes solid material caused by the precipitant from the mixture. The flowing material channel (102) feeds a stream of the mixture, from which the solid material has been at least partly removed, to the upper section (108) of the column (100).

This invention relates to a method for the continuous production of isopropanol-isooctane azeotropic mixtures by extractive distillation, characterized in that the apparatus for implementing this method mainly comprises the following parts: distillation column 1 (T1), distillation column 2 (T2), condenser 1 (CL1), condenser 2 (CL2), top storage tank 1 (C1), top storage tank 2 (C2), reboiler 1 (H1), reboiler 2 (H2), cooler (COL), and centrifugal pump 1 (P1); wherein distillation column 1 (T1)... 1) The bottom stream enters distillation column 2 (T2), and high-purity isopropanol is collected from the top stream of distillation column 1 (T1). The bottom product of distillation column 1 (T1) enters distillation column 2 (T2), and high-purity isooctane is collected from the top stream of distillation column 2 (T2), completing the separation of components. High-purity extractant is obtained at the bottom of distillation column 2 (T2), and after passing through a cooler (COL), it enters a centrifugal pump (P1). After cooling, extractant is added and then refluxed to distillation column 1 (T1). The extractant used is essentially non-volatile, which reduces extractant loss and allows for reuse, thereby reducing separation costs.