Abstract: In the water purification process, apparatus, and method, contaminated water vapor is exposed to liquid solvent, which causes a transfer of contaminants from the contaminated water vapor to the liquid solvent. In an advantageous embodiment, this latter step is followed by a second purification step where the decontaminated water in liquid phase is exposed to water vapor which causes a transfer of solvent remaining in the decontaminated water to the water vapor. The energy freed during the condensation of the vapor can advantageously be used for evaporation of the liquids, optionally by compressing the vapors prior to condensation thereof within heat exchangers.

Abstract: The claimed method and apparatus relate to cryogenic technology, particularly to purifying and separating by distillation a target heavy component concentrate thereby obtaining target components, e.g., krypton and xenon, and isotopes of light gases such as deuterium, tritium, helium-3. The method includes temperature-stabilizing a target heavy component concentrate flow, a low-boiling target component fraction flow, and a high-boiling target component fraction flow, irradiating the flows with ionizing radiation thereby obtaining light gas isotopes, purifying the flows, concentrating the light gas isotopes in the flows with subsequently extracting thereof, purifying the production flows from nuclides, using xenon as the high-boiling target component of the concentrate and using krypton as the low-boiling target component of the concentrate. The claimed apparatus can be used for implementing the method.

Abstract: Procedure of refining crude olive pomace oil obtained through centrifuging or decantation of the pomace, comprising the stage of filtration of the starting crude olive pomace oil carried out through filters having a pore size comprised in the interval from 0.1 to 20 microns and at a temperature below 70° C., preferentially between 35 and 45° C.

Abstract: A method of enriching a heavy oxygen isotope by distillation of the present invention includes: a first distillation step of feeding oxygen and ozone generated by an ozonizer 12 into a distillation column 13 filled with a diluent gas, and separating the oxygen, and the ozone and the diluent gas; a photodecomposition step of introducing a mixed gas of the ozone and the diluent gas from a bottom of the distillation column into a photoreaction cell 14, and irradiating the mixed gas with a laser light to selectively decompose the ozone containing the heavy oxygen isotope; and a second distillation step of returning non-decomposed ozone and oxygen containing the heavy oxygen isotope to the distillation column, and separating the oxygen, and the ozone and the diluent gas.

Abstract: In a method for recovering acid from an aqueous etching mixture containing HF, HNO3, H2SiF6 and HNO2 which has been used for purifying polycrystalline silicon, the used etching mixture is distilled progressively so that approximately from 20 to 50 wt. % of the mixture is distilled off as dilute acid containing more than 90 wt. % of the silicon dissolved as hexafluorosilicic acid in a first fraction, and the water contained in the used etching mixture having been reduced by approximately 10-30 wt. %, this water-depleted mixture is then concentrated by evaporation to a residue of about 1 to 5 wt. % of the initial amount of used etching mixture during which a second fraction is distilled off, and the residue is disposed of.

Abstract: A multi-effect evaporator, having an upstream and a downstream end, adapted for distillation of water. It comprises a plurality of effects serially connected and arranged into groups. Each group has a common parallel water feed inlet adapted to supply all effects in the group with feed water. The evaporator further includes a main feed water line in fluid communication with the most upstream group. An array of heaters is disposed along the line, adapted for heating the feed water before its entry into the effects of the latter group. Each effect comprises means for forwarding the second outlet vapor into one of the heaters for heating the feed water. Each group comprises a pump adapted to extract the concentrate from the effects of the group and pump it into the common parallel water feed of an adjacent downstream group.

Abstract: A distillation device (1) includes at least one first distillation region (5) with at least one first gas outlet line (6) and at least one second distillation region (8) with at least one further gas outlet line (9, 9?). The distillation regions (5, 8) are connected to each other. The first distillation region (5) is formed by a first line, the second distillation region (8) by a second line, and both lines forming the distillation regions (5, 8) are connected to each other in a controllable way. The invention further relates to methods for operating such a distillation device (1).

Abstract: A method of evaporating liquid in a liquid evaporating system having heat exchangers, evaporators, and steam reheaters, includes: preheating condensed water in the heat exchangers; distilling in the evaporators the condensed water from the heat exchangers, wherein the evaporators each has a horizontal plane evaporating chamber at an upper side thereof and a horizontal plane steam heating chamber at a lower side thereof, wherein heating steam is provided from an external boiler to the heating chamber; exchanging heat between the evaporating chamber and the heating chamber using a heat exchange boundary face formed in a concavo-convex shape, wherein the heat exchange boundary face is formed of a metal plate; and reheating in the steam reheaters the steam from the respective evaporators, wherein the reheaters each are coupled to a subsequent one of the heating chambers to serve as a heating source of the subsequent heating chamber.

Abstract: Fat-soluble trace constituents contained in plant tissues may be conveniently concentrated and/or purified by a method which involves extracting the fat-soluble trace constituent from a plant, to obtain an extract containing the fat-soluble trace constituent; adding a fatty acid ester to the extract, to obtain a mixture; and subjecting the mixture to molecular distillation. The method is particularly effective for the concentration and/or purification of fat-soluble constituents which are solids or viscous liquids at ambient temperature and ordinary pressure. The concentrated and/or purified fat-soluble trace constituent of a plant tissue prepared by the method may be combined with a food or drink to afford a food or drink product that contains the concentrated and/or purified fat-soluble trace constituent.

Abstract: A multistage evaporation system is proposed in which the first evaporator is heated via a jet wet washer with superheated, air-containing waste steam, for example of a drier. The product vapor of the first evaporator stage is fed via a mechanical compressor to a second evaporator stage for heating. The compressor ensures firstly a lowering of the dew point in the evaporator space of the first evaporator stage and secondly a temperature increase of the product vapor fed to the second evaporator stage for heating.

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: The present invention relates to a continuous process for preparing neral (cis-citral) in pure or enriched form by distillatively separating neral from substance mixtures comprising essentially neral and geranial (trans-citral). This distillative separation is performed in a dividing wall column or in a connection of two distillation columns in the form of a thermal coupling.

Abstract: The invention relates to a process for preparing 1-butenic fractions having less than 2000 ppm of isobutene in relation to 1-butene from technical mixtures of C4 hydrocarbons I which contain at least 1-butene and 2000 ppmw to 8% by mass of isobutene based on the 1-butene, with or without n-butane, isobutane and/or 2-butenes.

Abstract: The present invention generally relates to the small-scale separation of a mixture of two or more components with different boiling points into enriched fractions. In some embodiments, a first and second fluid (e.g., a liquid and a gas, a liquid and a liquid, etc.) are passed through a channel. The first fluid may comprise at least two components, each with a unique boiling point. Upon contacting the first and second fluids within the channel, at least a portion of the most volatile of the components in the first fluid (i.e., the component with the lowest boiling point) may be transferred from the first fluid to the second fluid. In some instances, the transfer of the volatile component(s) from the first fluid to the second fluid may be expedited by heating, in some cases above the boiling point(s) of the component(s) to be transferred from the first fluid to the second fluid. Contact between the first and second fluids may be maintained, for example, via segmented flow, bubbling flow, etc.

Abstract: According to one embodiment of the invention, a vapor-compression evaporation system includes a plurality of vessels in series each containing a feed having a nonvolatile component, a mechanical compressor coupled to the last vessel in the series and operable to receive a vapor from the last vessel in the series, a pump operable to deliver a cooling liquid to the mechanical compressor, a tank coupled to the mechanical compressor and operable to separate liquid and vapor received from the mechanical compressor, a plurality of heat exchangers coupled inside respective ones of the vessels, the heat exchanger in the first vessel in the series operable to receive the vapor from the tank, at least some of the vapor condensing therein, whereby the heat of condensation provides the heat of evaporation to the first vessel in the series, and wherein at least some of the vapor inside the first vessel in the series is delivered to the heat exchanger in the next vessel in the series, whereby the condensing, evaporating, a

Abstract: The present invention provides tube bundle configurations for multi stage flash cross tube type evaporators using concepts with parallel and counter current coolant flow. Those tube bundle configurations allow to build the evaporators more compact and provide the possibilities to lower the thermal and electrical energy consumption for a multi stage flash desalination plant by maintaining or reducing the distilled water generation cost as achievable with cross tube evaporators utilizing single pass tube bundles in serial flow communication.

Abstract: Separation and purification of hydroquinone from crude mixtures thereof essentially containing hydroquinone in combination with very small amounts of impurities including resorcinol and pyrogallol, include a topping distillation allowing the resorcinol to be removed as the distillation top product, and allowing a crude mixture essentially containing hydroquinone and the heavy impurities to be recovered at the column bottom, such mixture then being subjected to a bottoming distillation which allows the pyrogallol to be removed at the column bottom and allows hydroquinone in a purified form to be recovered at the column top.

Abstract: The process employs at least two distillation zones located within a column shell to produce an overhead and bottoms product from the first distillation zone and an intermediate product from the second distillation zone. Fluid is withdrawn from a side draw stage in the first distillation zone and passed through a conduit to the second distillation zone. A partition envelopes the second distillation zone to prevent mass transfer with the first distillation zone proximate the partition. The second distillation zone may be located relative to the first distillation zone to benefit from heat transfer across the partition.

Abstract: The present invention provides a process for distillatively purifying tetrahydrofuran in the presence of a polar solvent.

Abstract: Process for the polymerization of ethylene or of ethylene with further 1-olefins, in which the ethylene is polymerized in the presence of a catalyst in a gas-phase reactor and reaction gas comprising propane and unpolymerized ethylene is circulated to remove the heat of polymerization, wherein the polymer particles are discharged continuously or discontinuously from the reactor, the polymer particles are separated from the major part of the concomitantly discharged gas and the polymer particles are degassed, the gas is freed of entrained fine particles and is separated from a low-boiling fraction comprising ethylene or from a high boiling fraction containing further 1-olefins or alkanes having from 4 to 12 carbon atoms in a first separation stage, a propane fraction is separated off in a second separation stage and this propane fraction is used for degassing the polymer particles discharged from the reactor, with the proportion of ethylene in the propane fraction being less than 1 mol % and the proportion of

Abstract: The present invention provides a process for purifying 2-chloro-5-chloromethyl-1,3-thiazole represented by the formula (I): characterized in that a crude 2-chloro-5-chloromethyl-1,3-thiazole represented by the formula (I) is treated with a lower alcohol before the distillation, and then is distilled. The present purification process is a new one for purifying 2-chloro-5-chloromethyl-1,3-thiazole, suitable for industrial practice.

Abstract: Process for the continuously operated purification by distillation of the methanol used as solvent in the synthesis of propylene oxide by reaction of a hydroperoxide with propylene, with the methoxypropanols being separated off simultaneously, wherein the solvent mixture obtained in the synthesis is separated in a dividing wall column into a low-boiling fraction including methanol, an intermediate-boiling fraction containing the methoxypropanols as azeotrope with water and a high-boiling fraction including water and propylene glycol.

Abstract: A krypton-xenon concentrate is first divided into krypton and xenon fractions in a preliminary rectifying column. Semi-volatile impurities are removed from each fraction, and production krypton and xenon are obtained from the refined fractions in krypton and xenon production columns. A recovered krypton flow is produced in a krypton recovery rectifying column. Reflux is formed in condensers-evaporators of rectification columns of the device in such a way that the formation of a solid phase is excluded. The operation of the rectification columns is initiated by supplying krypton to a contacting space.

Abstract: A method for optimizing the production of nitration grade toluene from a solvent extraction process that produces an aromatic rich extract and a saturate rich raffinate, comprising adding an effective amount of the raffinate back to the extract.

Abstract: The present invention relates to a process for the production of MDI fractions containing 2,4?-MDI, and in which the 2,2?-MDI component from the MDA production is largely removed from the isomer mixture. Highly reactive monomeric MDI products can be produced in this way. These MDI products are characterised in their processing by significantly reduced emissions of MDI monomers.

Abstract: A process for light water detritiation which includes the steps of water distillation for tritium stripping and enriching, followed by chemical conversion of tritium enriched water to elemental hydrogen, and finally by one or more thermal diffusion columns for final tritium enrichment. The combination of process steps takes advantage of water distillation large throughput capability at low tritium concentration with the simplicity of thermal diffusion for small throughput final tritium enrichment. The water distillation front-end and the thermal diffusion back end processes are compatible with any intermediate chemical conversion process such as electrolysis or water gas shift reaction to convert tritiated water to elemental hydrogen.

Abstract: A process for dewatering hydrocyanic acid by distillation, which includes distilling crude hydrocyanic acid containing from 50 to 99.9% by weight of HCN, from 0.1 to 40% by weight of water, from 0 to 15% by weight of carbon oxides and optionally from 0.01 to 1% by weight of an involatile stabilizer, at a pressure of from 1 bar to 2.5 bar, a bottom temperature of from 100° C. to 130° C. and a top temperature of from 25° C. to 54° C., in the absence of a volatile stabilizer, in a distillation column to obtain a top draw stream containing purified, anhydrous hydrocyanic acid and carbon oxides and a bottom draw stream including water and, optionally, the involatile stabilizer.

Abstract: A liquid distributor for use in a column having distillation trays has been developed. The liquid distributor functions to uniformly distribute a descending liquid stream across the tray for interaction with an ascending vapor stream. The liquid distributor has a feed pipe which delivers the liquid stream to an underlying elongated trough. Liquid discharge holes are positioned in the floor of the trough. A perforated v-plate positioned within the trough so that liquid from the feed pipe passes through the perforated v-plate before encountering the floor of the trough. When liquid passes through the perforated v-plate, the stream is divided into smaller streams of lower velocity, providing a more uniform overall flow rate of liquid passing through the trough. Liquid is then delivered from the discharge outlets of the trough onto the upper surface of the tray with a substantially uniform flow rate across the trough.

Abstract: A method for the purification of pharmaceutical grade 1,1,1,2-tetrafluoroethane (HFC-134a) and polymer grade chlorodifluoromethane (HCFC-22) by contacting a mixture containing 1,1,1,2-tetrafluoroethane or chlorodifluoromethane and methyl chloride with a zeolite such as a molecular sieve, and recovering from said contacted mixture substantially purified 1,1,1,2-tetrafluoroethane or chlorodifluoromethane.

Abstract: A distillation unit (10) employs a rotary heat exchanger (32) forming a multiplicity of evaporation chambers (56) into which a liquid to be purified is sprayed for evaporation. Spray arms (58) spray at a steady rate into all of the evaporation chambers (56) simultaneously but not at a rate that is adequate to maintain the wetting required for efficient transfer of heat to the liquid. A scanning sprayer (140) supplements this steady spray with spray from nozzles (142 and 144) into only a few of the evaporation chambers at a time, visiting all of them cyclically. The overall rate of spray from the two sources thus combined to spray the chamber cyclically maintains proper wetting even though on average it is lower than the rate that would be required of a constant-rate spray into all of the evaporation chambers.

Abstract: A method and system for treating feedwater includes evaporating a portion of the feedwater in a first evaporation chamber so as to separate water vapor from the remaining feedwater. Droplets of the remaining feedwater are dispersed into a stream of hot air produced in a second evaporation chamber. The droplets evaporate and solids in the feedwater precipitate. The precipitated solids are collected in the lower section of the second evaporation chamber. Water vapor discharged from both evaporation chambers can be treated in a cyclone separator to remove residual solids therefrom. The cleansed water vapor output from the cyclone separator can be condensed to recover clean water. Dry solids can be discharged from the second evaporation chamber and the cyclone separator for recovery.

Abstract: This invention is an improved distillation sequence for the separation and purification of ethylene from a cracked gas. A hydrocarbon feed enters a C2 distributor column. The top of the C2 distributor column is thermally coupled to an ethylene distributor column, and the bottoms liquid of a C2 distributor column feeds a deethanizer column. The C2 distributor column utilizes a conventional reboiler. The top of the ethylene distributor is thermally coupled with a demethanizer column, and the bottoms liquid of the ethylene distributor feeds a C2 splitter column. The ethylene distributor column utilizes a conventional reboiler. The deethanizer and C2 splitter columns are also thermally coupled and operated at a substantially lower pressure than the C2 distributor column, the ethylene distributor column, and the demethanizer column. Alternatively, a hydrocarbon feed enters a deethanizer column.

Abstract: By using a dephlegmator which conducts distillation concurrently with heat exchange within at least one distillation column, or a portion of one distillation column, of a distillation cascade, the quantity of liquid holdup within the distillation apparatus is reduced and the start-up time is shortened. Consequently, the operational costs associated with startup are reduced, and productivity is improved markedly.

Abstract: Basic (meth)acrylates IV are prepared by transesterification of alkyl (meth)acrylates I in the presence of a catalyst and working-up of the reaction mixture by distillation, by a process in which a gas or gas mixture which is inert under the reaction conditions is passed through the reaction zone and/or heat exchanger.

Abstract: A process for light water detritiation comprised of water distillation for tritium stripping and enriching, followed by chemical conversion of tritium enriched water to elemental hydrogen, and finally by one or more thermal diffusion columns for final tritium enrichment. The combination of process steps takes advantage of water distillation large throughput capability at low tritium concentration with the simplicity of thermal diffusion for small throughput final tritium enrichment. The water distillation front-end and the thermal diffusion back end processes are compatible with any intermediate chemical conversion process such as electrolysis or water gas shift reaction to convert tritiated water to elemental hydrogen.

Abstract: The invention relates to an apparatus and a process for the preparation of anhydrous or substantially anhydrous formic acid. This apparatus is constructed partly or entirely of substantially zirconium-free materials. The extractant employed is a liquid of the general formula I where the radicals R1 and R2 are alkyl, cycloalkyl, aryl or aralkyl groups, or R1 and R2 jointly, together with the N atom, form a heterocyclic 5- or 6-membered ring, and only one of the radicals is an aryl group, and where R3 is hydrogen or a C1–C4-alkyl group. The apparatus has a synthesis reactor (6), a hydrolysis reactor (1), three distillation devices (2,4,5) and an extraction device (3).

Abstract: A liquid-liquid extraction process of ketones, alcohols, aldehydes, alkyl esters of carboxylic acids, carboxylic acids, ethers, amines and heterocyclic compounds, from their aqueous solutions, comprising the addition under stirring to said aqueous solutions of a fluorinated extracting liquid selected from A) hydrofluoropolyethers, B) hydrofluorocarbons, C) hydrofluoroethers, or mixtures thereof, with formation of an aqueous phase and of an organic phase; the separation of the organic phase from the aqueous phase; the fractional distillation of the organic phase to separate the polar organic substance from the extractant.

Abstract: A hydraulically sealed crossflow mass transfer tray, separating columns which contain the hydraulically sealed crossflow mass transfer tray and the use of such separating columns for thermal separating processes.

Abstract: Process for the purification of toluenediisocyanate from a crude distillation feed which includes toluenediisocyanate, an organic solvent and less than 2% by weight phosgene by separating the crude distillation feed in a dividing-wall distillation column into at least four product fractions P1–P4. P1 is a phosgene enriched low-boiler product, P2 is a solvent-enriched product, P3 is a high boiler enriched bottoms and P4 is a toluenediisocyanate product stream.

Abstract: Toluene diisocyanate is recovered from a crude distillation feed containing less than 2% by weight of phosgene by (a) fractionating the crude distillation feed containing less than 2% by weight of phosgene to remove the solvent and optionally the reaction residues to produce a crude toluene diisocyanate feed containing less than 20% by weight of solvent and (b) separating the crude toluene diisocyanate feed containing less than 20% by weight of solvent in a divided-wall distillation column into four product fractions P1–P4. P1 is a vapor phase low-boiler and solvent-enriched gas stream, P2 is a low-boiler and solvent-enriched product, P3 is a high boiler-enriched bottoms product containing toluene diisocyanate and P4 is a toluene diisocyanate product stream lean in low-boilers, high-boilers and reaction residues.

Abstract: Apparatus and processes are disclosed for economical separation of fluid mixtures. Broadly, apparatus of the invention is an integrated fractional distillation and perm-selective membrane separation apparatus. More particularly, the integrated apparatus comprises a fractional distillation column and one or more membrane device utilizing solid perm-selective membranes. Processes of the invention are particularly useful for simultaneous recovery of a very pure permeate product, a desired non-permeate stream, and one or more distillate products from a fluid mixture containing at least two compounds of different boiling point temperatures.

Abstract: Cultivated field water is desalinated by a series of independent units that float on the water surface, taking up the saline water with a wick, evaporating the water from the wick in desalinating relation by concentrating incident solar radiation with a combination of a lenses and cooperating mirrors onto the upper end portion of the wick while the wick lower end portion is immersed in the field water, capturing the desalinated vapor resulting by condensing within the unit and returning the condensed, desalinated water to the field, and periodically renewing the wick by rinsing the salt from it at a cleaning station beyond the field.

Abstract: A process and a device for the catalytic hydrolysis of a carboxylate, e.g., methyl acetate, ethyl acetate, i- or n-propyl acetate, i- or n-butyl acetate, allyl acetate and methyl formate, into the corresponding carboxylic acid and alcohol, by a combination of a pre-reactor and a reactive distillation column are disclosed. By the combination of a pre-reactor and a reactor distillation column, the conversion ratio can be substantially improved. The device can compensate for fluctuations in the supply quantity or in the composition of the feed flow. The product composition can also be controlled in a wide range.

Abstract: The invention provides a method for producing purified N-vinyl-2-pyrrolidone free of odorous components. The method is composed of distilling with a distillation column a liquid, which is formed by adding to an odorous components-containing liquid having a N-vinyl-2-pyrrolidone purity of not lower than 90 wt %, a compound having boiling point lower than that of N-vinyl-2-pyrrolidone, and whereby removing the odorous components together with said low-temperature boiling compound as the distillate.

Abstract: A process for evaporating a portion of a colloidal solution, said process including: a) passing a colloidal solution, said colloidal solution including particles in a liquid medium, wherein at least a portion of said liquid medium includes at least one volatile component, through one or more orifices into an evaporation zone that has at least one inner surface, wherein said colloidal solution does not substantially contact said at least one inner surface of said evaporation zone as said colloidal solution is passed through said evaporation zone; b) applying pressure in said evaporation zone that is lower than the vapor pressure of said colloidal solution as it is passed into said evaporation zone, allowing for flash evaporation of at least a portion of said at least one volatile component from said colloidal solution; c) adjusting the pressure in said evaporation zone to evaporate an amount of said at least one volatile component from said colloidal solution; and d) collecting the remaining colloidal solution

Abstract: A process for preventing undesired polymerization is conducted by maintaining an effective concentration of a stabilizer which comprises N-oxyl radicals in a mixture containing ethylenically unsaturated compounds, wherein (i) an electronic signal which correlates with the concentration of the N-oxyl radicals in the mixture is obtained periodically or continuously, (ii) the electronic signal is compared with a reference value, and (iii) addition of a stabilizer to the mixture is controlled according to the comparison (ii). The signal is preferably obtained by ESR measurement. The process permits efficient use of the stabilizer.

Abstract: A desalination apparatus capable of obtaining fresh water stably at low cost by utilizing low-temperature waste, wherein the desalination apparatus including a heat exchanger 92 cooperating with an evaporation can 60 so as to subject a low-temperature waste heat 11 and raw water 62 in the evaporation can 60 to heat exchange and generate water vapor 63 in the evaporation can 60; a condenser 98 cooperating with a raw water tank 72 so as to receive the water vapor 63 from the evaporation can 60, cool the water vapor 63 by subjecting the water vapor 63 and raw water 71 in the raw water tank 72 to heat exchange and obtain distilled water 76; a distilled water tank for storing the distilled water 76; vacuum means for evacuating the evaporation can 60 and depressurizing the inside thereof so as to promote generation of water vapor 63 in the evaporation can 60; and raw water supply means for supplying raw water to the evaporation can.

Abstract: A membrane distillation method includes the steps of preparing a membrane distillation module that includes a hydrophobic porous membrane which is permeable to gas or vapor and impermeable to the solution, and injecting a body of the solution into the membrane distillation module and forming nano-grade gas bubbles of inert gas in the solution in the membrane distillation module in such a manner that the solution is emulsified with the nano-grade gas bubbles and that the thus formed nano-grade gas bubbles are allowed to pass through the membrane from one side to the other side of the membrane.

Abstract: The present invention relates to a method of treating condensates containing compounds, which are more volatile than water, in an evaporation plant, where liquid, such as effluent liquid from a pulp or paper mill is evaporated in multiple effects and where condensates generated in the evaporation are flashed and purified in a steam stripping column. In the method, the condensates from at least two evaporation effects are combined and flashed together, and the vapor obtained from the flashing is made to contact with a condensate stream to be purified in the stripping column, wherefrom the impurities-containing vapor and the purified condensate stream are discharged.

Abstract: A method for recovering hexamethylene diamine (HMD) from a mixture comprising HMD, 6-aminocapronitrile (ACN) tetrahydroazepine (THA), and ADN comprising: