Abstract: This invention relates to a process for reducing the corrosion rate of iron-containing vessels within an ethylene glycol distillation system. The inventive process includes the addition of an additive component of sodium nitrite and sodium hypophosphite into such iron-containing vessels, to thereby react with iron of the inside walls and form a protective coating thereon. This process reduces the corrosion rate in iron-containing vessels of the apparatus, and reduces the catalytic effects of iron corrosion products within the system. Thus, not only is the on-stream time of the vessels extended, but also product quality is improved by reducing the aldehyde content of the final ethylene glycol product.

Abstract: A method for distilling ethanol from a mash includes feeding a fluid to a first distillation column. The fluid and a distillate of the first distillation column are delivered to a second distillation column. The fed fluid and/or distillate of the second distillation column is/are purified in a first and/or last step of the method by a membrane separation process.

Abstract: The invention is a process for the purification of ethanol. In one embodiment the process includes boiling a degassed beer feed (106) in a pre-boiler (110) to provide a vapor by-pass fraction (112) that by-passes the conventional beer column and is fed into the rectifier column (124). The process allows free capacity in the rectifier column of new or established plants to be filled by ethanol-water vapor and/or condensate streams that do not originate from the beer column.

Abstract: An apparatus including an ethanol stream, wherein said ethanol stream contains greater than 5% of water; a dehydration means, wherein the water content of said ethanol stream is reduced to less than 5%; a desiccation means, wherein the water content of said ethanol stream is reduced to less than about 1%; a 200 proof receiver, wherein said 200 proof receiver comprises a sample port or a sensor to allow the percentage of water in the ethanol to be determined, and wherein said 200 proof receiver comprises an outlet; a heat exchanger to heat said ethanol stream with less than 1% water, and a mixing manifold downstream of said heat exchanger, wherein said heated ethanol stream with less than 1% water is combined with fusal oils from a fusal oil decanter is provided.

Abstract: This invention is directed to methods for recovery of C3-C6 alcohols from dilute aqueous solutions, such as fermentation broths. Such methods provide improved volumetric productivity for the fermentation and allows recovery of the alcohol. Such methods also allow for reduced energy use in the production and drying of spent fermentation broth due to increased effective concentration of the alcohol product by the simultaneous fermentation and recovery process which increases the quantity of alcohol produced and recovered per quantity of fermentation broth dried. Thus, the invention allows for production and recovery of C3-C6 alcohols at low capital and reduced operating costs.

Abstract: A process is described for the recovery of substantially pure ethyl acetate from a feedstock including ethyl acetate, ethanol and water. The process includes supplying the feedstock to a first distillation zone maintained under first distillation conditions effective for distilling from the feedstock a first distillate including ethyl acetate, ethanol, and less than about 10 mol % water. The first distillate is recovered from the first distillation zone and is supplied to a second distillation zone maintained under second distillation conditions, which include use of a higher pressure than that of the first distillation zone. The second distillation conditions are effective for distilling from the first distillate a second distillate including ethanol, water, and a minor proportion of ethyl acetate and yielding a substantially pure ethyl acetate bottom product, which is recovered. The second distillate is returned to the first distillation zone.

Abstract: Methods and apparatus for producing alcohols from syngas are disclosed herein. In some variations, syngas is catalytically converted to alcohols. The alcohols can be subjected to drying to produce an intermediate alcohol product, followed by distilling the intermediate product to produce a purified ethanol product for use in liquid fuels.

Abstract: The systems and methods described herein provide for modified lignins and other compositions that may be useful as entrainers. In embodiments, they may be useful for dehydrating ethanol so that it can be used as an energy source.

Abstract: A process for separating vapours, for example for separating water from ethanol, uses a gas separation membrane unit. Permeate from the membrane unit is compressed and may be used for example as heating steam for distillation. The membrane unit may have two or more stages. Permeate from a stage may be condensed and used for example as fermentation make up water, compressed and fed to the permeate from an upstream stage or heating steam, or fed to another membrane stage for further dewatering. The gas separation membrane unit may be used to remove water from a fermentation broth that has been partially dewatered, for example by one or more of a distillation column or molecular sieve.

Abstract: The invention relates to a method of avoiding corrosion in the separation of methylamine from a product stream (10) which is obtained in the preparation of methylamines by gas-phase reaction of methanol and ammonia and includes monomethylamine, dimethylamine, trimethylamine, ammonia and methanol as components, where ammonia is separated off by pure distillation in a first column (1), the remaining components of the product stream obtained as bottoms (12) are fed to a second column (2). Trimethylamine (14) is separated off in the second column (2) by extractive distillation with introduction of water. The further of the product stream obtained as bottoms (15) from the second column (2) are fed to a third column (3), in which monomethylamine and dimethylamine are separated off at the top. The monomethylamine and dimethylamine are separated by distillation in a fourth column (4). To avoid corrosion alkali metal hydroxide is added to the second or third column (3).

Abstract: Method of regenerating a glycol solution containing water, hydrocarbons and salts. The glycol solution is expanded in drum (2), then distilled in column (7). The concentrated glycol collected at the level of reboiler (8) is placed under vacuum to vaporize the water and to precipitate the salts. The salts are separated from the glycol in separation device (13). The concentrated glycol freed of the salts is stored in capacity (16).

Abstract: The invention is a method to purify tertiary butyl alcohol by contact with at least two solid adsorbents comprising aluminum oxide and a large pore zeolite such as zeolite X. The purification method successfully improves product quality and reduces the amount of impurities in the tertiary butyl alcohol.

Abstract: A process for producing high purity isopropyl alcohol. In one embodiment, the process includes the steps of: (a) feeding a feed stream comprising at least about 99.9 wt. % isopropyl alcohol into a separation column; (b) separating the isopropyl alcohol into an overhead stream taken overhead from the separation column and a bottoms stream taken as bottoms from the separation column; and (c) removing the high purity isopropyl alcohol at a point: (i) below where the feed stream enters the separation column but above the bottoms stream, or (ii) above where the feed stream enters the separation column but below the overhead stream. The high purity isopropyl alcohol has a metals content of less than about 1 ppb and a water content of less than about 100 ppm.

Abstract: A process for the distillative recovery of high purity monoethylene glycol from the hydrolysis, product of ethylene oxide by pressure dewatering, preferably in a battery, vacuum dewatering and subsequent purifying distillation, wherein during the vacuum dewatering an aqueous stream is withdrawn which contains-monoethylene glycol in a concentration below 1% by weight, preferably below 0.1% by weight, medium boilers and low boilers. The withdrawn aqueous stream is, optionally after further workup, removed from the system.

Abstract: Process for dewatering organic liquids admixed with water wherein the admixture is brought into contact with a molecular sieve. The moleculat sieve is pretreated so as to reduce its acid site concentration and attain an ammonia TPD value of 18 mmol/g or less prior to contact with the admixture. The present invention relates to a process for dewatering organic liquids admixed with water, said process comprising bringing the admixture into contact with a molecular sieve, characterized in that the molecular sieve is pretreated so as to reduce its acid site concentration and attain an ammonia TPD value of 18 mmol/g or less prior to contact with the admixture.

Abstract: A method of separating ethanol and ethyl acetate, and ethanol and water involves distilling a mixture of the components by an extractive distillation process in the presence of an extractive distillation solvent. The extractive distillation solvent may be an amine, an alkylated thiopene, and paraffins.

Abstract: A chemical refining and reuse method and apparatus efficiently remove water from a waste chemical used in a semiconductor device fabrication process. The method is superior to conventional refining methods, in that water is removed at the end of the refining process, followed only by particle removal, so that water is not reintroduced into the waste chemical during metallic impurity removal. Therefore, the refined waste chemical has a percentage of water therein which is equal to that of the chemical in an initial raw state. The method includes: a) removing ionic impurities contained in the waste chemical; b) removing metallic impurities contained in the waste chemical after removing the ionic impurities; c) removing water contained in the waste chemical after removing the metallic impurities; and d) removing particles contained in the waste chemical after removing the water.

Abstract: Contaminated glycol in a natural gas dehydration plant is refined by vacuum distillation. The equipment to perform the refining by vacuum distillation is mounted upon a trailer. The equipment on the trailer is connected by an inlet line to the dehydration plant to receive the contaminated glycol from the plant. The refined glycol is continuously pumped back to the dehydration plant by a conduit. Detergents may be added to the glycol unit so that the circulating glycol cleans the equipment of the dehydration plant as the hazardous materials is separated from the glycol. The dehydration plant remains in operation during the time that the glycol is refined and the dehydration plant equipment cleaned. When the process is complete at one dehydration plant the trailer is towed to another dehydration plant for refining the glycol and cleaning the dehydration plant.

Abstract: Butanol and dibutyl ether are separated from a mixture containing water, dibutyl ether and n-butanol, 2-butanol and/or isobutanol by a process in whicha) the mixture is introduced into a first distillation column, essentially butanol is separated off at the bottom of this distillation column and the mixture taken off at the top of the distillation columnb) is introduced into a second distillation column and essentially dibutyl ether is separated off at the bottom of this second distillation column and the mixture formed at the top of the second distillation column is removed,c) the second distillation column being operated at a higher pressure than the first distillation column and at least one of the two mixtures taken off via the top of the distillation columns being subjected to phase separation, only the organic phase separated off being fed to the second distillation column in the case of phase separation downstream of the first distillation column, and separation into an aqueous and an organic phase als

Abstract: The invention relates to a process for preparing .alpha.,.omega.-C.sub.4 -C.sub.20 -alkenols by catalytic monodehydration of .alpha.,.omega.-alkanediols over a catalyst system comprising the combination of aluminum phosphate and barium phosphate. The gas-phase dehydration which occurs over this catalyst at temperatures of from 300 to 500.degree. C. advantageously combines selectivity with a high space-time yield while simultaneously enabling a high throughput over the catalyst.

Abstract: A process as been found for the removal of water from reaction mixtures of acids or acid anhydrides or of aqueous alkali metal hydroxide solutions with alcohols using vapor permeation/pervaporation at the boiling point of the reaction mixture, which includes initially introducing the lowest-boiling educt in less than the stoichiometric amount, based on the other particular educt, together with this other educt, heating the reaction mixture to the boiling point and freeing the vapor mixture, which is formed from the boiling reaction mixture and includes chiefly water and the lowest-boiling component, from water on a membrane, recycling the vapor mixture which has been freed from water into the reaction mixture and topping up the reaction mixture with the lowest-boiling educt in the course of the reaction.

Abstract: A dehydration catalyst useful for producing a monoalkylether of dihydric phenolic compound by a dehydration reaction of a dihydric phenolic compound with a lower alkyl alcohol with a high conversion at a high selectivity, comprises at least one inorganic substance of the empirical formula (I):Al.sub.a P.sub.b Ti.sub.c Si.sub.d X.sub.e O.sub.f (I)wherein X represents a member selected from the group consisting of (1) an antimony and/or a bismuth atom, and (2) a sulfur atom, a, b, c, d, e and f respectively represent the numbers of Al, P, Ti, Si, X and 0 atoms, the atomic ratio a:b is 1:1.0 to 1.9, the atomic ratio a:c is 1:0.05 to 0.5, the atomic ratio a:d is 1:0.05 to 0.2, the atomic ratio a:e is 1:0.01 to 0.3 when X represents antimony and/or bismuth atom and 1:0.004 to 0.015 when X represents a sulfur atom, and the atomic ratio a:f is 1:4.1 to 8.4.

Abstract: A method and apparatus permits concentration of a water-miscible organic liquid in a mixture of such liquid and water, with recovery of a desired concentrate of the water-miscible organic liquid and water, and a relatively clean water containing only a very low content of the water-miscible organic liquid which enables disposal of the water in sewage systems, the method and apparatus thus enhancing the ability to satisfy environmental concerns; the method has particular application to the recovery of a reusable glycol/water mixture from diluted spent aircraft deicer fluid (ADF).

Abstract: Acetone cannot be separated from a mixture of isopropanol and water because of the closeness of their boiling points. Acetone can be easily separated from isopropanol and water by extractive distillation. Effective extractive agents are 1-nitropropane, 3-carene, dimethylsulfoxide and 3-pentanone.

Abstract: A method for the on-site reprocessing of isopropyl alcohol used in semiconductor manufacturing, to generate an ultradry and ultrapure isopropyl alcohol. This ultradry and ultrapure isopropyl alcohol is produced through a pervaporation step, followed by double distillation. In the first distillation step, an autonomous azeotropic self-stripping distillation column is used to produce an ultradry and partially purified isopropyl alcohol. In the next step, the isopropyl alcohol is distilled in an overhead product distillation column, to produce an ultrapure and ultradry isopropyl alcohol. Alternatively, if the feed isopropyl alcohol contains less than 2000 ppm water, the pervaporation step may be omitted.The resulting isopropyl alcohol has between a high of 100 parts per million (ppm) and a low of 0.1 ppm of water in the isopropyl alcohol. It also has zero particles per milliliter of a size larger than 2.0 microns, zero to 2 particles per milliliter of a size of 0.5 micron to 2.

Abstract: Acetaldehyde may be effectively removed from a contaminated methanol stream using a distillation method wherein a solvent stream containing a relatively heavy polar compound such as water or propylene glycol is utilized as an extractive distillation solvent. Following the separation of the polar compound from the bottoms stream obtained by extractive distillation, the purified methanol may be recycled for use as a reaction solvent in an olefin epoxidation process.

Abstract: Ethanol, isopropanol and water cannot be separated from each other by distillation or rectification because of minimum azeotropes. They are readily separated by extractive distillation. Effective agents are: dimethylsulfoxide for ethanol, phenol for isopropanol.

Abstract: Ethanol, isopropanol and water cannot be separated from each other by rectification because of the presence of minimum azeotropes. They are readily separated by azeotropic distillation. Effective agents are cyclopentane for ethanol from water, methyl acetate for isopropanol from water.

Abstract: A method and apparatus for removing water from a solution of water and glycol solution. The apparatus finds application in recycling of glycol wherein a water and glycol solution having as much as a 95% water content when introduced to the apparatus leaves the apparatus with a water content in the order of 40% to 60%. The glycol concentrator has a packing medium made from glass shards that provide a labyrinth through which air is circulated in one direction and thin streams of glycol are circulated in generally the opposite direction. It is believed that mixing of the thin streams of solution and air flow steams in the labyrinth results in a thin film evaporation process. The glycol concentrator apparatus has reduced energy requirements when compared with a distilling process.

Abstract: For the regeneration of a liquid desiccant, a stripping agent is used which is liquid at ambient temperature and pressure, and forms a heteroazeotrope with water, along with the following steps: (a) distillation of the water-laden liquid desiccant to form vapor and partially regenerated liquid desiccant; (b) reboil partially regenerated liquid desiccant; (c) stripping of partially regenerated liquid desiccant during (a) and (b), using vaporized stripping agent; (d) a condensing of vapor the exiting the distillation, the condensation producing two liquid phases, one mainly water and the other mainly stripping agent; (e) heating the stripping agent-rich liquid phase exiting step (d) to generate a vapor phase which is richer in water than said liquid phase and a water-depleted liquid phase; and (f) returning the vaporized liquid phase exiting step (e) to step (c).

Abstract: A method of separating a liquid mixture wherein the liquid mixture is heated; the heated liquid mixture is supplied to a pervaporation membrane module to separate a permeable component of the liquid; a portion of non-permeated liquid is circulated through a circulation pipe into a liquid mixture feeding pipe before a heater, and the remaining portion of the non-permeated liquid is extracted to the outside of the system, and wherein the temperature of the liquid in the liquid mixture feeding pipe in which the non-permeated liquid has been mixed with the liquid mixture or in the circulation pipe for the non-permeated liquid, is measured, and when the measured temperature is out of a predetermined range, new supply of the liquid mixture and/or extraction of the non-permeated liquid is stopped.

Abstract: A first alkanol having 1 to 3 C atoms or a mixture of this first alkanol with water or water itself can be separated off from oxygen-containing organic compounds having 3 to 7 C atoms from the group comprising second alkanols and dialkyl carbonates, which always have at least 2 C atoms more than the first alkanol, by permeation on membranes if a membrane obtained by plasma polymerization is employed.

Abstract: For separating ETBE and ethanol the following principal stages are employed:(1) Extraction of ethanol by water, the raffinate being ETBE saturated in water and the extract an ethanol/water mixture containing a small proportion of ETBE;(2) Concentration of the above mixture, the distillate being a mixture close to the ethanol/water azeotrope in composition and containing a very small proportion of ETBE;(3) Heteroazeotropic distillation of this distillate in two coupled columns with an overhead decanter, this distillation using ETBE as azeotroping agent; the residue of the first column being ethanol which is ca. 99% by mole and the residue of the second column being practically pure water, this water and the water recovered during the concentration stage being used as extraction solvent in stage (1).Stage (3) may be an ethanol dehydration unit using ETBE as dehydrating agent.

Abstract: This invention relates to a process for the production of absolute alcohol from aqueous alcohol, whereby saving of energy to a greater extent is rendered possible in a more simple process, as compared with the prior art azeotropic distillation method using benzene or cyclohexane. That is, aqueous alcohol is subjected to extractive distillation in a first distillation column under such a condition that a liquid and gas of a solvent simultaneously coexist using low pressure propane, propylene and butane as the solvent, absolute alcohol substantially free from water is recovered from the bottom of the distillation column and subjected to stripping of hydrocarbons in a second distillation column, during which the gaseous phases of the first and second distillation columns are mixed and compressed, utilized through recompression as a heat source of a reboiler of the first distillation column, subjected to separation of water content and recycled to the upper parts of the first and second distillation columns.

Abstract: A method of continuously distilling off the components of a mixture containing phenols, water and methanol using a single distillation column, wherein methanol is recovered from the top of the column, water containing phenols is dragged as a side stream from a recovery section of the column, and phenols are recovered as a bottom product. The method permits efficient separation by the single distillation column of the three components with high purity and low utility energy.

Abstract: A coolant recycling apparatus has a boiler and condenser for distilling a glycol and water from a used coolant. The glycol and water are recombined in a mixing tank to form a mixture having a desired ratio of water to glycol, and an inhibitor is added to the mixture to obtain a fresh coolant mixture ready for use in an engine cooling system. Contaminants in the used coolant are concentrated to form a sludge.

Abstract: A method and an apparatus to condense and rectify alcohol, and more particularly to a method and an apparatus suitable for the energy-saving condensation and rectification of high-purity alcohol from the synthesized alcohol, the used alcohol aqueous solution in food industry and the fermented alcohol.The method makes it possible to extract and recover alcohol of 99 wt % or higher with small quantity of propane solvent, using the propane in supercritical or pseudocritical conditions in the process of condensation and recovery of alcohol from aqueous solution of alcohol. Further, the method makes it possible to condense alcohol to the concentration of 95 wt % or higher by increasing the selectivity of alcohol through the cooling of the propane to liquid state.

Abstract: According to the process of this invention, alcohols are recovered from aqueous acid solution by permeation of the alcohol through an organic-acid modified polymer membrane. An improved process for the manufacture of alcohols by acid absorption of olefins is also disclosed, the improvement residing in the use of an organic-acid modified polymer membrane to selectively permeate alcohols from the concentrated aqueous strong acid solution thereof co-produced in their synthesis from olefins.

Abstract: A lower alcohol is recovered from a mixed liquid thereof with water, derived from a vapor drying procedure for a water-wetted article, for example, a water-washed lens or semiconductor wafer, by feeding the mixed liquid of a lower alcohol with water from the vapor drying procedure to a vaporizer; vaporizing the mixed liquid; feeding the mixed vapor into a gas-separating module comprising at least one gas-separating membrane, for example, composed of a aromatic polyimide hollow fiber, which allows a selective permeation of water vapor from a feed side to a permeated side therethrough, withdrawing a non-permeated vapor fraction containing the lower alcohol in an increased concentration from the feed side, and converting the vapor fraction to a high purity lower alcohol liquid by cooling, while discharging a permeated vapor fraction containing water in an increased concentration from the permeated side.

Abstract: A method of distillation employing a heat pump (which may be driven by a compressor) using a vapor stream from within the distillation system as a heat source and a liquid stream from within the distillation system as a heat sink. The selection of heat-source vapors and heat-sink liquid is such that at least one is withdrawn from the phase-contracting region of the distillation system. The return of streams withdrawn from the phase-contacting region of the distillation system to the distillation system is such that at least one of the streams is returned at a temperature different from that of the point from which it was withdrawn, and all withdrawn streams are returned in manner such that a stream removed as vapor is returned at a point with a temperature at most that at the point it was withdrawn, and a stream removed as liquid is returned at a point with a temperature at least that at which it was withdrawn.

Abstract: A process for obtaining a substantially dry alcohol from a mixture comprising alcohol and water in a non-azeotropic amount by utilizing at least a portion of the alcohol in the mixture as the stripping medium.

Abstract: Isopropanol and n-propanol cannot be completely separated from water by conventional distillation or rectification because of the minimum boiling azeotrope. Isopropanol and n-propanol can be readily separated from water by using azeotropic or extractive distillation. Typical examples of effective agents are: for isopropanol by azeotropic distillation, vinyl n-butyl ether; by extractive distillation, polyethylene glycol; for n-propanol by azeotropic distillation, amyl formate; by extractive distillation, n-butyl acetate.

Abstract: t-Butyl alcohol cannot be completely separated from water by conventional distillation or rectification because of the minimum boiling azeotrope. t-Butyl alcohol can be readily separated from water by using azeotropic or extractive distillation. Typical examples of effective agents are: by azeotropic distillation, vinyl n-butyl ether and propylene glycol dimethyl ether; by extractive distillation, 1,3-butanediol and triethylene glycol.

Abstract: A preparation membrane for pervaporation which comprises a crosslinked reaction mixture of a polyvinyl alcohol or polyvinyl alcohol copolymer and a polystyrene sulfonic acid or polystyrene sulfonic acid copolymer. A method for separating a mixture of water and an organic compound by using the membrane is also disclosed.

Abstract: The present invention relates to a method and an apparatus to condense and rectify alcohol, and more particularly to a method and an apparatus suitable for the energy-saving condensation and rectification of high-purity alcohol from the synthesized alcohol, the used alcohol aqueous solution in food industry and the fermented alcohol.The invention provides a method, which makes it possible to extract and recover alcohol of 99 wt % or higher with small quantity of propane solvent, using the propane in supercritical or pseudocritical conditions in the process of condensation and recovery of alcohol from aqueous solution of alcohol. Further, the method makes it possible to condense alcohol to the concentration of 95 wt % or higher by increasing the selectivity of alcohol through the cooling of the propane to liquid state.

Abstract: A thermally-integrated extractive distillation process for recovering anhydrous ethanol from fermentation or synthetic feedstocks has a distillation train of four columns. Two columns are preconcentrators operated in parallel. The remaining columns are an extractive distillation dehydrating tower, and an entrainer-recovery column. The two preconcentrators and the dehydrating tower are operated at three successively increasing pressures so that the condensing vapors of the overhead product of the dehydrating tower supply the necessary heat to the reboiler of the intermediate-pressure preconcentrator. The overhead vapors of this preconcentrator are, in turn, used to supply the required heat to the reboiler of the lowest-pressure preconcentrator. The bottom product from each preconcentrator is used to preheat the dilute feed. Additional energy savings are accomplished by the appropriate heat exchange between the various feeds, overheads, and bottoms.

Abstract: A purification process for methyl methacrylate (MMA) and a recovery process for methanol are disclosed. A mixture, which contains water, methanol and methyl methacrylate (MMA) as principal components along with at least one of methyl acrylate, methyl propionate and methacrylic acid, is azeotropically distilled together with hexane to obtain MMA in a form substantially free of water, methanol methyl acrylate, methyl propionate and hexane and a low boiling-point fraction. The low boiling-point fraction is cooled and separated into a water phase and an oil phase. Methanol can be recovered from the water phase by adding an alkaline substance to it and then distilling the resultant mixture. A preparation process of MMA is also disclosed. MMA can be prepared by esterifying methacrylic acid or methacrylamide with methanol and then applying the above purification process.

Abstract: An improved method for dehydration and concentration of an aqueous solution containing an organic compound is disclosed. The solution is evaporated to produce a gaseous mixture comprising an organic compound vapor and a water vapor. The water vapor is selectively removed from the gaseous mixture by permeation through an aromatic polyimide gas separation membrane while the gaseous mixture being kept in contact with a surface on one side of the gas separation membrane at a temperature of 70.degree. C. or higher to obtain a gaseous mixture comprising the organic compound vapor and a reduced amount of a water vapor.

Abstract: A process for separation of components of a mixture of more than one organic substance or of a mixture of at least one organic substance and water by extraction using a supercritical fluid as an extractant. During the extraction an extraction aid having a higher affinity with an unextractable component of the mixture than with an extractable component of the mixture is present. Also disclosed is an apparatus for carrying out this process.

Abstract: A pervaporation process for separating at least one component from a mixture of liquids, for example for separating ethanol from a fermentation mass, by a series of three separation steps: separating the mixture by a first pervaporation to form a first permeate vapor enriched in the component to be separated; fractionating the first permeate vapor, for example by temperature condensation, to form a high concentration fraction twice enriched in the component to be separated; and either distilling the high concentration fraction or a second pervaporation to form a distillate or retentate liquid thrice enriched in the component to be separated.