358 results about "Extractive distillation" patented technology

The invention discloses a continuous synthesis and purification method of hexafluoropropylene oxide, which comprises the following steps: introducing hexafluoropropylene, oxygen and a fluorine-containing solvent into a supergravity reactor to carry out oxidation reaction at the reaction temperature of 100-200 DEG C under the reaction pressure of 1.0-2.5 Mpa for 10-120 seconds, and after the reaction is finished, overflowing and leading out reaction liquid to obtain the hexafluoropropylene oxide. And purifying to obtain the hexafluoropropylene oxide. According to the method, the problems of mass transfer and heat transfer can be effectively solved by using the supergravity reactor, the reaction selectivity is remarkably improved, meanwhile, the productivity is effectively improved, and the supergravity reactor is combined with extractive distillation treatment, so that the conversion rate of the hexafluoropropylene reaches 79% or above, the selectivity of the hexafluoropropylene oxide is 85% or above, and the purity of the hexafluoropropylene oxide after extractive distillation reaches 99%. The invention further discloses a device used in the continuous synthesis and purification method, and cyclic utilization of hexafluoropropylene and the fluorine-containing solvent can be achieved.

The invention discloses a crude phenol continuous refining device and method, the device comprises a crude phenol storage tank, a dehydrating tower, a primary tower, a phenol fraction tower, an o-cresol fraction tower, a m-cresol and p-cresol tower, an extractive distillation tower and a p-cresol fraction tower which are connected in sequence, and the top of each tower is independently connected with a cooler; the method specifically comprises the following steps: (1) discharging phenol water; (2) discharging a heavy fraction; (3) discharging phenol; (4) discharging o-cresol; (5) discharging residual oil at the bottom of the tower; (6) carrying out extractive distillation, and discharging m-cresol; and (7) discharging p-cresol, and recycling the extraction agent. Compared with a traditional continuous rectification process, the method has the advantages that all components are separated by adopting vacuum rectification, the separation degree of the obtained product is higher, the number of theoretical plates and energy consumption are lower, high-purity phenol products are produced with low energy consumption, low cost and high efficiency, and economic benefits and environmental benefits are greatly improved.

The invention provides a method and a device for separating azeotrope of ethanol and dimethyl carbonate, and the method comprises the following steps: adding raw materials into an extractive distillation tower for extractive distillation, and then carrying out first heat exchange and condensation on a compressed top gas phase of the extractive distillation tower and a bottom liquid phase of the extractive distillation tower to obtain a dimethyl carbonate product; sequentially carrying out first reboiling, first flash evaporation, two times of heat exchange, second reboiling and second flash evaporation on the heat-exchanged bottom liquid phase of the extractive distillation tower to obtain a second flash evaporation gas phase and a second flash evaporation liquid phase; carrying out second heat exchange on the second flash liquid phase and the first flash liquid phase, condensing, and returning to the extractive distillation tower; and pressurizing the second flash evaporation liquid phase, performing third heat exchange with the first flash evaporation liquid phase after primary heat exchange, and condensing to obtain an ethanol product. The method is low in energy consumption, the solvent is not easy to volatilize, and the ethanol and the dimethyl carbonate in the azeotrope can be effectively separated.

The invention discloses a separation method of a phenol-cyclohexanone azeotropic system, a separation system and application. The separation method comprises the following steps: separating a material containing phenol, cyclohexanone and impurities and a material containing an extraction agent in an extractive distillation tower, and extracting the material containing cyclohexanone from the tower top; extracting a material containing phenol, impurities and an extracting agent from the tower kettle; the impurities comprise at least one of cyclohexylbenzene, ketal and a ketal dehydration product; feeding the material containing phenol, impurities and the extraction agent into a solvent recovery tower for separation, and extracting the material containing phenol from the tower top; a material containing the extraction agent and impurities is extracted from the side line of the tower and is cooled and separated by a phase splitter to obtain a light-phase material containing the impurities and a heavy-phase material containing the extraction agent; the heavy-phase material containing the extraction agent flows back to the solvent recovery tower and then flows back to the extractive distillation tower, so that recycling of the extraction agent is realized, the investment economic cost of the extraction agent is effectively saved, and the condition that the extraction agent needs to be regularly discharged as fuel or post-treated in the prior art is avoided.

The invention relates to a method for separating azeotrope of 1-fluoro-1, 1-dichloroethane and 1, 1, 1, 3, 3-pentafluorobutane through extractive distillation. According to the method for separating the 1-fluoro-1, 1-dichloroethane and the 1, 1, 1, 3, 3-pentafluorobutane azeotrope through extractive distillation, an extracting agent is added into the 1-fluoro-1, 1-dichloroethane and the 1, 1, 1, 3, 3-pentafluorobutane azeotrope, and the extracting agent is one or more of n-amyl alcohol and n-heptanol. The method adopts intermittent extractive distillation or continuous extractive distillation operation, and has the advantages of simple and efficient separation process, high product purity and the like. The loss rate of the extracting agent is low, the extracting agent can be recycled, and environmental pollution can be avoided.

The invention provides a continuous rectification recovery process of 1, 2-butadiene, which comprises the following steps: preheating a heavy C4 raw material and an extraction agent, feeding the preheated heavy C4 raw material and extraction agent into an extractive distillation tower, steaming out a light component A from the tower top, condensing, and returning to the tower top as reflux; the heavy component A is rectified in an extractant separation tower, a light component B is distilled out from the tower top, part of the light component B returns to serve as reflux, and the other part of the light component B enters a heavy component removal tower; the heavy component B returns to the extractive distillation tower through the heat exchanger. After heavy components of the light component B are removed in the heavy component removal tower, the light component C is evaporated out from the tower top, condensed and fed into a 1, 2-butadiene storage tank. And the heavy component C finally flows into a waste liquid tank. Wherein the heavy C4 raw material and the extraction agent are preheated by a heat exchanger, and the heat exchanger uses the heavy component B as a heat source. By providing a simple, feasible, economical and efficient continuous extractive distillation process, high-purity 1, 2-butadiene can be efficiently recovered from heavy C4 byproducts of a 1, 3-butadiene extraction device, and the content of the 1, 2-butadiene can reach 97%.

The invention relates to a method and a process for separating isopropanol-isooctane by using an N, N-dimethylacetamide (DMAC) organic extraction agent. The process is composed of an extractive distillation tower and a solvent recovery tower. According to the method, N, N-dimethylacetamide is used as an extraction agent, isopropanol-isooctane firstly enters an extractive distillation tower for extraction separation, high-purity isopropanol is obtained at the top of the extractive distillation tower, and materials at the bottom of the tower enter a solvent recovery tower for separation. High-purity isooctane is obtained at the top of the solvent recovery tower, and an extracting agent DMAC is obtained at the bottom of the solvent recovery tower. The method has the advantages of low energy consumption, simple process, convenience in operation, greenness, energy conservation, high purity of separated products and the like, and the adopted extracting agent N, N-dimethylacetamide is good in stability, non-toxic, low in corrosivity and environment-friendly.

The invention relates to a method for purifying an alkyl hydroperoxide from dialkyl peroxide thereof, comprising a step of distillation in the presence of alcohol and water followed by extraction of the condensates using a hydrocarbon or a hydrocarbon blend.

The invention discloses a binder-free granular carbon molecular sieve and application thereof in C4 olefin mixture separation, and belongs to the technical field of C4 olefin adsorption and separation. The granular carbon molecular sieve for C4 olefin mixture component separation is obtained by crushing a precursor, screening particles with a proper particle size as a carbon source, and then performing carbonization and pyrolysis in a tubular furnace. The granular carbon molecular sieve disclosed by the invention is high in adsorption capacity, high in selectivity, good in stability, high in particle strength and easy to recycle and regenerate, and can be directly used for industrial devices. Compared with the traditional solvent absorption, extractive distillation and low-temperature distillation technologies, the separation method provided by the invention has the advantages of low energy consumption, small equipment investment, environmental friendliness and the like, and has a wide application prospect in the field of C4 olefin component separation.

The disclosure relates to a process for separating a hydrocarbon-containing feedstock stream by extractive distillation, wherein the feedstock stream is contacted with a water-soluble solvent for aromatics in countercurrent. An aliphatics fraction is distillatively removed as aliphatics product stream from the mixture obtained. The aromatics are stripped from the aromatics-enriched solvent that remains and the aromatics-depleted solvent is recycled in a solvent circuit, with compounds having a lower boiling point compared to the solvent accumulating in the solvent circuit as impurities. At least a substream of the solvent circuit is purified for removal of the impurities, wherein the substream for the purifying is subjected to a thermal separation process, in which the impurities are at least partly discharged in a top product and the purified solvent that remains is recycled into the solvent circuit. An apparatus for carrying out the process is also disclosed.

The invention discloses a preparation method of 2, 2, 4-trimethyl-1, 2-dihydroquinoline, and relates to a preparation method of 2, 2, 4-trimethyl-1, 2-dihydroquinoline. The method comprises the following steps: by taking o-aminoacetophenone and isobutenyl magnesium bromide as raw materials, reacting in the presence of a polymerization inhibitor and a solvent, then adding water to decompose, extracting, distilling to remove the solvent and lightly separating to obtain high-purity and high-yield 2, 2, 4-trimethyl-1, 2-dihydroquinoline. By adopting the method, carcinogenic primary amine impurities are not generated.

The invention provides a method for extracting, rectifying and separating an ethano-2-pentanone azeotropic system by using a tetramethylammonium chloride eutectic solvent, and relates to the technical field of extracting, rectifying and separating the ethano-2-pentanone azeotropic system, which comprises the following steps: taking an ethano-2-pentanone mixture as a raw material to be separated; the method comprises the following steps: mixing and stirring a hydrogen bond acceptor and a hydrogen bond donor according to a certain proportion and temperature to obtain the eutectic solvent, firstly heating a material S01 to be separated by a heat exchanger E101 and then entering the middle part of a T101 tower, adjusting a eutectic solvent material flow S02 to a proper temperature and then entering the upper part of the T101 tower, carrying out heat exchange on a tower top ethanol material flow S03, enabling a part of material flow S05 to flow back to the tower top, and carrying out heat exchange on a tower top ethanol material flow S03; according to the method, a specific eutectic solvent is adopted as an extracting agent, an extractive distillation process is matched, an ethano-2-pentanone azeotropic system can be effectively broken, the yields of ethanol and 2-pentanone can reach 99% or above finally, the purities of ethanol and 2-pentanone can reach 99.5% (mass percent) or above finally, and efficient separation is achieved.

The invention relates to a method for recovering nickel and cobalt from a mixture of compounds of these metals from the recycling of spent lithium-ion batteries, comprising the following steps: a) digestion of a mixture of nickel and cobalt compounds in a solution containing hydrochloric acid having a concentration of more than 25 mass %, in case the mixture of nickel and cobalt compounds is solid; or bringing the mixture of nickel and cobalt compounds to a hydrochloric acid concentration of more than 25 mass %, in case the mixture of nickel and cobalt compounds is a solution; b) activation of ion-exchange resin in a column using hydrochloric acid; c) passing the solution from step a) through the column filled with the ion-exchange resin activated in step b); d) washing the column with hydrochloric acid having a concentration of more than 25 mass % in order to wash out the remaining solution containing nickel ions; e) washing the column with hydrochloric acid having a concentration of less than 10 mass % in order to wash out cobalt ions; f) extraction distillation of the nickel ion solution obtained in step d) in hydrochloric acid using sulfuric(VI) acid; phase separation in a spent liquid; recycling of a filtrate to distillation; dissolution of nickel sulfate(VI) and electrolysis in order to recover metallic nickel; g) extraction distillation of the cobalt ion solution obtained in step e) in hydrochloric acid using sulfuric(VI) acid; phase separation in a spent liquid; recycling of a filtrate to distillation; dissolution of cobalt sulfate(VI) and electrolysis in order to recover metallic cobalt; h) extraction distillation of the solution of diluted hydrochloric acid with nickel and cobalt ions obtained after the activation of the ion-exchange resin in step b), using sulfuric(VI) acid; phase separation in a spent liquid; recycling of a filtrate to distillation; recycling of a mixture of the formed cobalt sulfate(VI) and nickel sulfate(VI) to digestion in step a); i) rectification of diluted hydrochloric acid having a concentration below the azeotropic concentration (approx. 20.2 mass % at atmospheric pressure) formed in extraction distillation processes in steps f)-h) in order to concentrate hydrochloric acid and recover and recycle of water; recycling of concentrated hydrochloric acid to extraction distillation in steps f)-h).

Inhibitor compositions for abating undesirable emulsion polymerization during processing of hydrocarbon stream laden with reactive vinylic monomers are provided. The polymerization inhibitor compositions include at least a first inhibitor compound having a stable nitroxide radical and a second inhibitor including phenylenediamine. Methods of inhibiting the polymerization of monomers using the compositions of the disclosure are also provided. The methods of inhibiting polymerization of monomers include a step of adding a composition of the disclosure to a process stream. The process stream includes an ethylenically unsaturated monomer that is suspended in the bulk-phase and highly polar solvents as distractive distillation solvents.

The utility model discloses a separation device for ethyl acetate and cyclohexane, which belongs to the technical field of separation and purification, solves the problems of incapability of large-scale separation, high process difficulty and poor separation effect in the prior art, and comprises an extractive distillation tower, the upper part is provided with a polyol solvent inlet, the top is connected with a first condenser, the outlet of the first condenser is connected with a cyclohexane outlet on the other side of the upper part of the extractive distillation tower, and the cyclohexane outlet is connected with a re-separation device. According to the device disclosed by the utility model, the problem of azeotropy of ethyl acetate and cyclohexane is solved by adding polar polyol, the relative volatility of the ethyl acetate and the cyclohexane is changed, and large-scale efficient separation of a mixture of the ethyl acetate and the cyclohexane is realized; the dissolubility of cyclohexane, sodium acetate and ethanol in water is different, so that the separation effect of cyclohexane is further improved, and the whole device is simple in structure.

The invention discloses a preparation method of 2-hydroxy-4-(methylthio) butyric acid, and belongs to the technical field of chemical engineering, 2-hydroxy-4-(methylthio) butyronitrile and acidic resin are subjected to a hydration reaction and a hydrolysis reaction, then extractive distillation treatment is performed to recover an extraction agent, and the product 2-hydroxy-4-(methylthio) butyric acid is obtained; according to the invention, the acidic resin is used for replacing free acid, so that the corrosion to equipment is reduced, the possibility of side reaction between concentrated acid and 2-hydroxy-4-methylthio butyronitrile is avoided, the content of impurity polymers is obviously reduced, and the yield of a main product reaches 99.8% or above; the generated resin ammonium salt is about 50% less than the inorganic ammonium salt generated by using free acid, so that the post-treatment cost is reduced; through the process method provided by the invention, the prepared 2-hydroxy-4-methylthiobutyric acid is high in purity, the content of impurities such as residual solvent and resin ammonium salt in the product is low, and efficient separation and purification are realized.

The invention relates to the technical field of chemical engineering, and discloses a separation method of tert-dodecyl mercaptan reaction liquid. According to the separation method, a specific sulfone substance is adopted as an extraction agent, and the specific sulfone substance and a tert-dodecyl mercaptan reaction solution to be separated are subjected to extractive distillation in an extractive distillation tower, so that high-purity tetra-polypropylene can be obtained at the top of the extractive distillation tower; and rectifying and separating tower bottoms of the extractive distillation tower to obtain high-purity tert-dodecyl mercaptan. Therefore, according to the separation method, the separation purity of the tetra-polypropylene and the tert-dodecyl mercaptan can be obviously improved, and the problem that the tetra-polypropylene and the tert-dodecyl mercaptan are difficult to separate in the prior art is solved.

The invention relates to the technical field of extractive distillation, in particular to a plant essence extractive distillation method, device and system, and the method comprises the following steps: acquiring temperature data, pressure data and flow data; acquiring average temperature data at each moment, respectively recording the average temperature data, the pressure data and the flow data as related data, and acquiring oscillation degree values of various related data in the monitoring time period; respectively acquiring a first influence coefficient and a second influence coefficient of the monitoring time period; acquiring a coupling disturbance index in the current monitoring time period; acquiring an unbalance coefficient of temperature distribution in the current monitoring time period according to the temperature data at each moment; and the rectification abnormal coefficient of the current monitoring time period is obtained by combining the coupling disturbance index in the current monitoring time period, so that the prediction range parameter in the model prediction control technology in the next monitoring time period is obtained, and the reflux quantity of the next monitoring time period is adjusted. According to the method, the extractive distillation purity of the plant extract is improved by optimizing the prediction range parameters.

The invention relates to the technical field of separation and purification, in particular to a method and a device for separating and purifying aromatic hydrocarbon, alkane and olefin, and the method combines liquid-liquid extraction and extractive distillation (namely, first extractive distillation and second extractive distillation), so that the liquid-liquid extraction and the extractive distillation are operated in respective dominant zones. In liquid-liquid extraction, heavy alkanes with small solubility are separated, light alkanes with high relative volatility are separated in first extractive distillation, olefins with high relative volatility are separated in second extractive distillation, aromatic hydrocarbons and solvents are separated in solvent recovery, and finally, the same solvent is used to realize efficient separation of aromatic hydrocarbons, alkanes and olefins.

The invention relates to an extractive distillation device and a waste liquid recovery method. The extractive distillation device comprises an evaporator, a primary tower, an impurity removal tower, an extractive distillation tower and a product recovery tower which are sequentially communicated through pipelines; the evaporator is provided with a raw material inlet, a first liquid phase inlet, a first liquid phase outlet, a first gas phase outlet, a first steam inlet and a first steam condensate outlet, and the primary distillation tower is provided with a primary distillation gas phase inlet and a primary distillation liquid phase outlet; the first gas phase outlet is communicated with the primary distillation gas phase inlet through a pipeline, the first liquid phase inlet is communicated with the primary distillation liquid phase outlet through a pipeline, and the first liquid phase outlet is used for flowing out impurities. According to the device and the recovery method, MDG and NMF in the waste liquid are further separated by adopting the extraction agent, MDG and NMF products can be respectively recovered, and thus the industrial utilization value of the MDG and NMF mixture is expanded.

The invention provides a fused salt extractive distillation separation device for zirconium and hafnium tetrachloride, which comprises a rectifying tower, a reboiler, a reflux tank, a circulating tank, a sublimator, a gas preheater and a condenser, and during installation, all the parts are sequentially connected to obtain the complete zirconium and hafnium tetrachloride fused salt extractive distillation separation device. The device is simple in structure, easy and convenient to operate, convenient to connect and suitable for molten salt extractive distillation separation of zirconium-hafnium tetrachloride.

The embodiment of the invention provides an extractive distillation system, a control method and an extractive distillation process, and belongs to the technical field of chemical separation and purification. The extractive distillation system comprises an extractive distillation tower, a first condenser, a first reboiler, a first reflux tank, an extraction agent recovery tower, a second condenser, a second reboiler, a second reflux tank, a raw material preheater, a plurality of regulating valves, a plurality of material conveying pumps and control equipment, the control equipment comprises a first pressure controller, a second pressure controller, a first reflux tank liquid level controller, a first reboiler liquid level controller, a second reflux tank liquid level controller, a second reboiler liquid level controller, a first reflux ratio controller, a first cascade control loop and a second cascade control loop, a third cascade control loop and a fourth cascade control loop. The extractive distillation system has the technical effect of improving the purity of the obtained product.

The invention discloses a bamboo activated carbon production tail gas utilization method and a bamboo activated carbon production method.The utilization method comprises the following steps that production tail gas is subjected to condensation treatment, and condensate is obtained; carrying out solid-liquid separation treatment on the condensate to obtain permeate; performing extraction treatment on the permeate liquid by adopting an extraction agent to obtain a first extraction agent soluble liquid; carrying out reduced pressure distillation treatment on the first extractant soluble liquid to obtain distillate; performing extraction treatment on the distillate by adopting an extraction agent and water to obtain a second extraction agent soluble liquid; and carrying out reduced pressure distillation treatment on the second extractant soluble liquid to obtain the biomass oil. Through condensation treatment, solid-liquid separation treatment and two-stage extraction-distillation treatment, organic matter steam in carbonized tail gas is converted into biomass oil with a high calorific value (HHV), the overall additional value of bamboo activated carbon is increased, energy and chemical components of bamboo raw materials are utilized to the maximum extent, resource waste is reduced, and economic benefits of enterprises are increased.

The present invention discloses a low-odor phosphazene catalyst and its use. The catalyst comprises a phosphazene cation represented by the general formula (I) and an alkali metal salt compound anion. The catalyst is prepared by dissolving a phosphorus pentahalide and a guanidine compound in a non-benzene-based organic solvent and reacting them under heated conditions to obtain an organic phosphonium salt solution containing the organic solvent and the phosphorus halide compound. An alkali metal salt compound is then added and reacted under heated conditions in an inert atmosphere to obtain a purified phosphazene catalyst through filtration, reduced-pressure distillation, purification, and vacuum drying. The catalyst can be used in the production of polyether polyols and polyurethane foams. The phosphazene catalyst of the present invention employs a non-benzene-based inert solvent that does not participate in the reaction during production, eliminating the need for frequent solvent changes. Using the same solvent eliminates steps such as extraction and distillation, reducing energy consumption and wastewater generation during the process. The continuous production method for the phosphazene catalyst is efficient and environmentally friendly.

The invention discloses a method for separating a tert-amyl methyl ether-methanol-water azeotropic system by pressure swing extractive distillation through two different mixed entrainers on the basis of a heat pump technical process strengthening scheme. Through three-tower operation of an extraction vacuum distillation tower T1, an extraction vacuum distillation tower T2 and a solvent recovery tower T3, a methyl tert-amyl ether-methanol-water azeotropic mixed solution is separated, the purity of separated methyl tert-amyl ether is greater than 99.9%, the purity of methanol is greater than 99.9%, the yield is greater than 99.9%, the purity of water is greater than 99.9%, and the yield is greater than 99.9%. A heat pump technology is used as an effective process strengthening means, steam at the top of an extraction decompression rectifying tower T1 circularly enters a compressor to be compressed and heated through the compressor, the compressed steam serves as heat flow to heat cold flow at the bottom of the tower, and the top flow is finally condensed after heat transfer. And the reboiling flow at the bottom of the tower can reach the required reboiling ratio, so that the heat load consumption of the T1 tower is obviously reduced. By applying the method, the process cost and the environmental pollution can be further reduced, and the annual total cost and the gas emission are respectively reduced by 9.19% and 23.55%. According to the process, heat energy is fully utilized, energy consumption is reduced, the purity and the yield of the tert-amyl methyl ether are improved, and the equipment cost is reduced. The adopted mixed entrainer is small in dosage, relatively weak in volatility, small in extraction agent loss, easy to recover and environment-friendly.

The invention discloses a recovery method and application of ethylene glycol dimethyl ether, and belongs to the technical field of solvent recovery, and the recovery method comprises the following steps: mixing and stirring a recovery solvent and water, and standing for layering to obtain a lower water layer; distilling the water layer to obtain a distillation solvent; adding a dehydrating agent into the distillation solvent, stirring, and standing for layering to obtain supernatant liquid; and adding sodium filaments into the clear liquid for reaction, distilling and recovering ethylene glycol dimethyl ether. In conclusion, according to the recovery method and application of ethylene glycol dimethyl ether, through multi-step cooperative operation of extraction, distillation-alkaline dehydration and removal of tert-butyl alcohol from sodium filaments, accurate removal of impurities is achieved, the purity of solvent recovery in production of tert-butyl compounds is guaranteed, multiple targets of resource circulation, cost reduction and environmental protection standard reaching are achieved, and the recovery method and application of ethylene glycol dimethyl ether are suitable for industrial production. And a feasible technical scheme is provided for industrial sustainable production of the tert-butyl compound.

The invention discloses a device and a process method for separating n-hexane, acetone and chloroform by applying an extractive distillation technology to a dividing wall column, and relates to the technical field of chemical processes. The device comprises two parts: one part is an extractive distillation dividing wall tower, and the other part is a solvent recovery tower. According to the technical innovation, two extractive distillation towers in a conventional three-tower extractive distillation process are coupled into one dividing wall tower by utilizing a dividing wall tower technology, so that the dividing wall tower can be used for helping to industrially separate high-purity n-hexane, acetone and chloroform, meanwhile, the use cost of equipment is reduced, the use amount of circulating water and system heat energy is reduced, and the energy consumption is greatly reduced; and as the practicability and the economic benefit are remarkable, the method has a wide application prospect.

The invention relates to the technical field of neodecanoic acid preparation, and provides a high-purity neodecanoic acid preparation method which comprises the following steps: S1, adding a catalyst into a high-pressure kettle, introducing CO, injecting nonene, and reacting to obtain a reaction solution; s2, mixing the reaction liquid with an extraction agent, feeding the mixture into an extractive distillation tower, and performing extraction and separation to obtain a first organic phase; s3, adding water into the first organic phase, washing and separating to obtain a second organic phase; s4, adding an alkaline additive into the second organic phase, layering to obtain an upper-layer organic phase, and carrying out reduced pressure distillation on the upper-layer organic phase to obtain neodecanoic acid; in the step S1, the raw materials of the catalyst comprise supported cobalt oxide and concentrated sulfuric acid; the supported cobaltous oxide is prepared from the following raw materials: water-soluble cobalt salt and boron nitride; in the step S2, the extraction agent comprises 1, 2-propylene glycol. According to the technical scheme, the problem of low purity of neodecanoic acid in related technologies is solved.

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 relates to the technical field of chemical separation, and discloses an efficient tetrafluoropropanol separation method which comprises the following steps: S1, mixing an aqueous solution containing tetrafluoropropanol with a green extractant hydroxyethyl glucosamide according to a mass ratio of 1: 0.5-1: 2, and stirring at 25-40 DEG C for 20-40 minutes to form a uniform mixed solution; s2, inputting the mixed solution obtained in the step S1 into an extractive distillation tower, collecting water vapor at the top of the tower, and obtaining a mixture of tetrafluoropropanol and the green extractant at the bottom of the tower; s3, the tower bottom mixture obtained in the step S2 is cooled to 30-50 DEG C, deionized water is added for layering, the upper layer is high-purity tetrafluoropropanol, and the lower layer is an aqueous solution containing a green extraction agent; and S4, recycling the green extraction agent. According to the method, hydroxyethyl glucosamide is used as a green extracting agent, and an extractive distillation process is combined, so that an azeotropic system of tetrafluoropropanol and water is effectively broken, and the purity of the separated TFP reaches 99.5%-99.9%.