Abstract: N-Ethylpiperazine is isolated by distillation from a mixture consisting per 100 kg ofa=from 30 to 90 kg of N-ethylpiperazineb=from 7 to 40 kg of N,N'-diethylpiperazinec=from 3 to 20 kg of piperazined=from 0 to 30 kg of ethanole=from 0 to 40 kg of water andf=from 0 to 5 kg of concomitants,by performing the distillation in the presence of x=y+e= from 3b to 12b of water, y being the quantity of water which has to be added, if necessary, to meet this condition, and successively separating from this mixture the fractions1. water, ethanol, N,N'-diethylpiperazine and other highly volatile concomitants,2. water, if present in excess,3. piperzine and4. pure N-ethylpiperazineas overhead products.

Abstract: A process for purifying exo-2-hydroxy-1,4-cineole contaminated with ketones is carried out by derivatizing the ketone to form a compound readily separable from the desired cineole, either by distillation, solvent extraction or like separation process. In one embodiment method of the invention, derivatization is carried out by reaction of the ketone with an amine. The amine reacts with the ketone impurities to form water and relatively stable enamine derivatives that have a much lower vapor pressure than the exo-2-hydroxy-1,4-cineole. The desired product may then be separated by distillation.

Abstract: The instant invention relates to a process for the purification of dimethylether, which contains impurities, by feeding a mixture which contains the dimethylether at specific trays to a distillation column and withdrawal of the dimethylether and of impurities at specific trays of the same column.

Abstract: A method of producing a potable spirit comprises removing water from a fermented wash containing ethanol, water and congeners to produce a substantially water-free mixture of ethanol and congeners, and then fractionally distilling this water-free mixture of ethanol and congeners in the absence of water to produce a fraction containing substantially pure water-free potable ethanol. Preferably the fractional distillation is carried out in separate topping and tailing columns. This method provides an energy efficient separation of the ethanol and congeners.

Abstract: A method and apparatus for removing water from a liquid mixture of water and ethanol contacts it with liquid carbon dioxide so that the ethanol is preferentially transferred into solution, dries the solution using an adsorbent, and then recovers dry ethanol by distilling off the carbon dioxide. This process is particularly energy efficient especially when it includes a fermentation process to generate the ethanol and uses the carbon dioxide generated during the fermentation as the source of liquid carbon dioxide. In this case the method and apparatus provide an additional product of dry carbon dioxide.

Abstract: This document describes an improved method and apparatus for recycling energy in counterflow heat exchange and distillation. The basis of the invention is transferring heat with thin sheets of material having extensive surface area relative to the flow rate through the system. A distillation apparatus (11 and 12), a counterflow heat exchanger (11), a clothes dryer (FIG. 9), a power generator (FIG. 12), and other embodiments of the invention are described.

Abstract: A continuous process is described for the production of a substantially acid free dialkyl maleate, for example diethyl maleate, from a feed stream containing a major amount of dialkyl maleate and a minor amount of the corresponding monoalkyl maleate. This comprises continuously distilling the feed stream in a primary distillation zone, which can comprise a single distillation column or a series of distillation columns connected in series, so as to give (i) a bottom fraction containing monoalkyl maleate and dialkyl maleate in admixture, (ii) a vaporous fraction comprising alkanol, and (iii) an intermediate fraction that is substantially free from alkanol and comprises a major proportion of diethyl maleate and a minor proportion of maleic anhydride. The intermediate fraction (iii) is redistilled in a secondary distillation zone to yield (i) an overhead fraction containing maleic anhydride and (ii) a bottom fraction containing substantially acid free dialkyl maleate.

Abstract: In an industrial process for preparing indole by reacting aniline and ethylene glycol, high boiling-point impurities and non-volatile substances are removed in advance from the reaction mixture either before the recovery of aniline from the reaction mixture or before the subsequent rectification of the resultant indole. Indole of a high purity can thus be obtained.

Abstract: Isopropanol cannot be completely removed from isopropanol--isopropyl acetate--water mixtures by distillation because of the presence of the minimum ternary azeotrope. Isopropanol can be readily removed from mixtures containing it, isopropyl acetate and water by using extractive distillation in which the extractive agent is a higher boiling benzoate mixed with certain oxygenated or nitrogeneous organic compounds. Typical examples are butyl benzoate and ethylene carbonate; methyl benzoate, 2-nitropropane and n-decanol.

Abstract: n-Propanol and 2-butanol cannot be separated from each other by distillation because of the proximity of their boiling points. n-Propanol can be readily separated from 2-butanol using extractive distillation in which the extractive agent is a higher boiling oxygenated organic compound or a mixture of two or more of these. Typical examples of effective agents are: methyl benzoate; benzoic acid and methyl benzoate; cinnamic acid, phthalic anhydride and methyl benzoate.

Abstract: Isopropanol and t-butanol cannot be separated from each other by distillation because of the proximity of their boiling points. Isopropanol can be readily separated from t-butanol by using extractive distillation in which the extractive agent is a higher boiling oxygenated organic compound or a mixture of two or more of these. Typical examples of effective agents are: methyl benzoate; methyl benzoate and hexahydrophthalic anhydride; phthalic anhydride, hexahydrophthalic anhydride and methyl benzoate.

Abstract: A process for separating gaseous or liquid hydrocarbons in first and second fractionation zones wherein the first fractionation zone employs a side reboiler discharging below the side draw point. A vapor sidestream is removed from the first fractionator below the side draw point and introduced to the second fractionator. The flow scheme permits control of the first fractionator bottoms temperature to match available low level waste heat which may therefore be used in fractionator reboiling duty.

Abstract: Method and apparatus are provided for simultaneously producing various forms of alcohol, including ethanol, which can likewise be withdrawn from the apparatus simultaneously. To this end, successive columns in the individual processing stages, each of which includes distillation, rectification, purification and dehydration, are connected in parallel for product flow but in series for energy flow and conservation.

Abstract: Apparatus is provided for simultaneously producing various forms of alcohol, including ethanol, which can likewise be withdrawn from the apparatus simultaneously. To this end, successive columns in the individual processing stages, each of which includes distillation, rectification, purification and dehydration are connected in parallel for product flow but in series for energy flow and conservation.

Abstract: This document describes an improved method and apparatus for recycling energy in counterflow heat exchange and distillation. The basis of the invention is transferring heat with thin sheets of material having extensive surface area relative to the flow rate through the system. A distillation apparatus (11 and 12), a counterflow heat exchanger (11), a clothes dryer (FIG. 9), a power generator (FIG. 12), and other embodiments of the invention are described.

Abstract: Methyl t-butyl ether cannot be separated from close boiling hydrocarbons by distillation because of the proximity of their boiling points. Methyl t-butyl ether can be readily separated from close boiling hydrocarbons by using extractive distillation in which the extractive agent is higher boiling oxygenated, nitrogenous and/or sulfur containing organic compound or a mixture of two or more of these. Typical examples of effective agents are dimethylsulfoxide; dimethylsulfoxide and 2-octanone; dimethylsulfoxide, dimethylformamide and N-methyl pyrrolidone.

Abstract: Water cannot be completely removed from ethanol by distillation because of the presence of the minimum azeotrope. Ethanol can be readily dehydrated by using extractive distillation in which the water is removed as overhead product and the ethanol and extractive agent as bottoms and subsequently separated by conventional rectification. Typical examples of suitable extractive agents are hexahydrophthalic anhydride; methyl tetrahydrophthalic anhydride and pentanol-1; trimellitic anhydride, ethyl salicylate and resorcinol.

Abstract: Water cannot be completely removed from ethanol by distillation because of the presence of the minimum azeotrope. Ethanol can be readily dehydrated by using extractive distillation in which the water is removed as overhead product and the ethanol and extractive agent as bottoms and subsequently separated by conventional rectification. Typical examples of suitable extractive agents are methyl benzoate; trimellitic anhydride and methyl benzoate; dipropylene glycol dibenzoate, ethyl salicylate and resorcinol.

Abstract: A method and apparatus for separating at least one component of a mixture from another without the aid of gravity comprises, in one embodiment, a heat pipe structure having an inlet and spaced outlets, a wick element disposed within the heat pipe for inducing a capillary flow of condensed phase mixture in liquid form therealong and spaced heating and cooling elements for creating zones of higher and lower temperature, respectively, within the heat pipe structure. In an alternate embodiment, a sorbent column is provided having an inlet and spaced outlets, a sorbent material disposed along the inner wall of the column for inducing a flow of adsorbed mixture therealong and spaced heating and cooling elements for creating zones of higher and lower temperature.

Abstract: Separation and recovery of dibenzofuran of high purity is accomplished by distilling a coal tar fraction having boiling point range of 220.degree. to 300.degree. C. thereby producing a dibenzofuran fraction having a dibenzofuran content of not less than 30% by weight, a dibenzofuran/acenaphthene molar ratio of not less than 1.3, and a fluorene/dibenzofuran molar ratio of not more than 0.05, then introducing the dibenzofuran fraction obtained as described above into a continuous crystallization purification unit provided with a cooling zone for crystallization of the feed, a heating zone for melting the purified crystals, and a refining zone for enabling crystals being transferred from said cooling zone to said heating zone to come into counter current contact with a mass of molten crystals midway along the path between said two zones, and subjecting the dibenzofuran fraction to continuous crystallization purification therein.

Abstract: Methacrylonitrile higher in purity than that obtained by the conventional process is efficiently produced by the present improved process for producing purified methacrylonitrile in which the reaction mixture formed by the ammoxidation of isobutylene or tert-butyl alcohol is distilled using water as solvent to obtain a crude methacrylonitrile solution which contains methacrylonitrile as major constituent, methacrolein, hydrogen cyanide, and isobutyronitrile, and the crude methacrylonitrile solution is then purified in a product column, wherein the improvement comprises first removing isobutyronitrile from said crude solution, then feeding the remaining solution to the product column, withdrawing from the top a vapor containing methacrolein, condensing the vapor, returning a greater part of the condensate to the product column while removing the remainder from the distillation system, and withdrawing purified methacrylonitrile from the middle or lower section, preferably from a point lower than the feeding sta

Abstract: The invention relates to a process for the production of grade AA methanol by distilling raw methanol in several distillation stages, for separating grade AA methanol, tail gas, and fusel oil from the raw methanol and further processing the fusel oil to produce additional methanol of grade AA quality at a return ratio of 5:1 or higher.

Abstract: A C.sub.4 -hydrocarbon mixture which essentially contains n-butenes and butanes is separated by a process in whichthe mixture is reacted with a carboxylic acid in the presence of an acidic catalyst to form a butyl carboxylate,the reaction mixture obtained from the esterification zone is distilled to give, as the top product, a fraction containing the butanes, and, as the bottom product, a fraction containing the resulting butyl carboxylate,the butyl carboxylate is decomposed at elevated temperatures to give the carboxylic acid and n-butenes, andthe mixture of n-butenes and carboxylic acid is then distilled, the n-butenes being obtained as the top product, and the carboxylic acid as the bottom product.

Abstract: A process for the continuous isolation of phthalic anhydride and maleic anhydride from the reaction gases obtained by catalytic oxidation of o-xylene or naphthalene with air, wherein the reaction gases are treated with a hydrocarbon of boiling range from 115.degree. to 175.degree. C. as the solvent in a column, and are then treated with an organic solvent of boiling range from 180.degree. to 290.degree. C. in a second column, the phthalic anhydride and maleic anhydride being isolated from the liquid bottom product of the first column.

Abstract: A distillation apparatus is provided for the fractionation of a hydrocarbon stream. A part of the heat energy to operate the apparatus is provided by heat exchange of a recycled bottom liquid stream with an overhead vapor stream which has been compressed with a concurrent increase in temperature. Such an apparatus may be used to fractionate a C.sub.4 hydrocarbon feed.

Abstract: A method is disclosed for fractionating a hydrocarbon conversion zone effluent stream comprising at least three components which are to be isolated into separate streams. A two-column system for fractionating the effluent of a benzene alkylation zone is employed. The overhead vapor of a downstream second column is condensed in a side reboiler of a preceding recycle column. This side reboiler is located between the feed point to the recycle column and a separate reboiler located at the bottom of the recycle column. The utilities cost of performing the fractionation is reduced.

Abstract: The reaction product from etherification of C.sub.4 -C.sub.7 isoolefins with methanol in the presence of an acidic catalyst is washed with water in the presence of inert hydrocarbons thereby removing methanol and a part of the tertiary alcohol. The aqueous extract solution bottoms is distilled to separate methanol as overhead. Tertiary alcohols are withdrawn as a side stream from a tray of the distillation column with a high concentration thereof and fed into the washing column.

Abstract: A process for separating highly pure butene-2 and butene-1 from a C.sub.4 hydrocarbon fraction containing isobutane, n-butane, butene-1, butene-2, and at least one diolefinic hydrocarbon and/or at least one acetylenic hydrocarbon, which comprises, (1) as a step A, treating the C.sub.

Abstract: High purity alkyl glyoxylate is produced from complex mixtures containing alkyl glyoxylate, alkyl glycolate, water, alcohol and miscellaneous impurities. High purity alkyl glyoxylate is useful in the synthesis of alkyl glyoxylate polymers.

Abstract: Apparatus for carrying out thermodynamic processes in which a work medium undergoes mutually opposite phase transitions. The apparatus comprises casings consisting of confining plates and spacers therebetween, the casings being arranged in stacked relationship. Each casing encloses a plurality of phase transition compartments in superposed relationship. There are orifices in the confining plates through which pairs of phase transition compartments open directly into one another so as to form a number of work chambers. These are also passages delimited by the spacers in the casings for connecting the work chambers in series and passages delimited by the spacers in the casings for introducing and drawing work medium into and from the phase transition compartments. Finally, there are passages delimited by the spacers in the casings for supplying and abducting heat to and from the work medium.

Abstract: A process for recovering trioxane from an aqueous solution containing trioxane and triethylamine by the distillation separation process which comprises feeding an aqueous solution containing trioxane and triethylamine to the first distillation column, distilling out triethylamine, trioxane and water from the column top of the first distillation column, withdrawing an aqueous solution containing the major part of the trioxane present in the fed solution from the column bottom of the first distillation column, feeding the withdrawn solution to the second distillation column and taking out the substantially whole quantity of the trioxane fed to the second distillation column from the column top of the second distillation column.

Abstract: Methanol and cyclohexane are recovered from a condensed methanol-cyclohexane azeotrope by allowing the condensed azeotrope to separate in a vessel into an upper phase rich in cyclohexane and a lower phase rich in methanol, fractionating the upper phase in a first column whereby the methanol-cyclohexane azeotrope is taken off the top and returned to the vessel while cyclohexane is removed from the lower portion of the first column, and fractionating the lower phase in a second column whereby the methanol-cyclohexane azeotrope is taken off the top and returned to the vessel while methanol is removed from the lower portion of the second column.

Abstract: A process for isolating isobutene from C.sub.4 -hydrocarbon mixtures containing isobutene by reacting the mixture with a primary alcohol in the presence of an acid condensing agent, to form the tertiary ether, separating off the unconverted hydrocarbons and decomposing the tertiary ether in the presence of an acid catalyst at an elevated temperature, wherein a primary C.sub.3 - or C.sub.4 -alcohol is used and the temperature at which the reaction mixture leaves the etherification stage, in which the tertiary ether is formed, is lower than the mean temperature in the etherification stage.

Abstract: There is disclosed an improved process for the preparation of monochloroacetone by reacting acetone and chlorine in a vapor-liquid phase reactor and passing the reactor effluent through a fractionator to remove the liquid phase consisting mainly of monochloroacetone (MCA). The fractionator vapor phase effluent is consisting of acetone, hydrogen chloride, some monochloroacetone, and some reaction by-products sequentially fractionated in a series of condensers of varying temperatures such that the hydrogen chloride is isolated free of impurities and the remaining reaction materials, consisting mainly of acetone with some dissolved hydrogen chloride are available for recycling back into the reactor. The hydrogen chloride, isolated in the vapor phase, may be quenched with water to produce concentrated aqueous hydrochloric acid which may be used in other chemical procedures or it may be compressed into anhydrous hydrogen chloride.

Abstract: The treatment of raw water, particularly the desalination of waste or other water with a high salt content, is accomplished by means of a process which includes two membrane separation steps performed in concentrate sequence. The concentrate from the second membrane separation step is further treated by means of a thermal concentrating procedure. The water to be processed is first treated to minimize the formation of scale during the first membrane separation step and the concentrate from the first membrane separation step is similarly treated. The overall process also includes the production of materials necessary for reconditioning ion exchange apparatus employed for raw water conditioning and concentrate treatment.

Abstract: A method for separating close-boiling chlorosilanes by the procedures of extractive distillation using sulfolane as the extractive solvent is described. An example of close-boiling chlorosilanes which can be separated by this method include dimethyldichlorosilane and methyltrichlorosilane containing mixtures. The invention comprises heating a mixture of the close-boiling chlorosilanes with sulfolane to distill the lower-boiling chlorosilane from the mixture and thereafter separating the sulfolane and the high-boiling chlorosilane.

Abstract: A solar desalting method and apparatus includes a storage tank for receiving heated sea water at a first rate from a solar collector during daylight hours and for delivering the same to a flash evaporator a second rate. The flash evaporator is connected for delivery of the evaporated and unevaporated portions of the feed water as the heating vapor and feed liquid, respectively, to a serially connected multi-effect film evaporator. Sea water is used to condense the vapor from the last evaporator effect as the distillate product of the system. The storage tank permits nighttime operation with the brine from the last effect and a portion of the cooling water being fed to the solar collector during the daytime and discharged at night.

Abstract: Process for purifying hexamethyldisiloxane contaminated with toluene or other solvents that cannot be completely separated from the hexamethyldisiloxane by distillation, based on the discovery that hexamethyldisiloxane forms a previously unknown azeotrope with acetonitrile. This azeotrope has a heavier phase that is rich in acetonitrile and a lighter phase that is rich in hexamethyldisiloxane. These phases are mutually immiscible. The azeotrope starts to boil at 71.4.degree. C., which permits the hexamethyldisiloxane to be separated at relatively low temperatures from the impurities. The process involves one or more entrainment distillations in the presence of an excess of acetonitrile and the re-separation of the acetonitrile from the resulting lighter phase by distillation. Two further novel azeotropic systems, one consisting of hexamethyldisiloxane and toluene and the other of acetonitrile and toluene, are provided.

Abstract: Ethylene oxide and water are reacted in a reactor and the reaction product is subjected to distillation in a plurality of distillation columns, in the first columns water and components having a boiling point below that of monoethylene glycol and higher ethylene glycols, if any, being distilled off. To obtain extremely pure monoethylene glycol alkali metal compounds are added at a point between the reactor and the monoethylene glycol distillation column in an amount to adjust the pH of the product entering the latter column to a value of from 7 to 10. The monoethylene glycol obtained in this manner is especially pure and has very low UV absorption values. It is, therefore, especially suitable for the manufacture of polyester fibers.

Abstract: A continuous method and apparatus for distilling a liquid include conducting the distilling liquid through at least two successive distillation units operating at different temperature levels. The distilling liquid is vaporized in each distillation unit and the obtained vapor condensed into distillate by conducting the vapor into heat exchange relationship with the liquid discharged from the evaporators in a succeeding distillation unit which operates at a lower temperature level. At least one of the distillation units includes a plurality of communicating distillation stages, each distillation stage including an evaporator and a corresponding condenser.

Abstract: A contaminated solvent is first distilled in a distillation chamber (12) to drive off a substantial portion of the solvent which is condensed and recovered leaving a residual slurry (18) consisting of some solvent and the contaminants. A metering device (21) is cyclically operated to transfer precise amounts of slurry to a second distillation chamber where the slurry is deposited in an annular trough (26) formed in a heat plate (25). A spreader including a number of blades (27) moves the deposited slurry charge along the trough to an exit opening (44). The residual solvent in the slurry charge is vaporized, condensed and fed back into the first chamber (12). The remainder of the charge is exited through the trough opening (44) into a collection barrel (50) which is vented to pass back any solvent vapors to the second distillation chamber.

Abstract: Tri- and dichlorosilanes formed by hydrogenation in the course of the reaction of metallurgical silicon, hydrogen and recycle silicon tetrachloride are employed as feed into a separation column arrangement of sequential separation columns and redistribution reactors which processes the feed into ultrahigh purity silane and recycle silicon tetrachloride. A slip stream is removed from the bottom of two sequential columns and added to the recycle silicon tetrachloride process stream causing impurities in the slip streams to be subjected to reactions in the hydrogenation step whereby waste materials can be formed and readily separated.

Abstract: Acetone having a markedly low content of aldehydes is recovered from an aqueous rectification residue brought about by rectification of crude acetone carried out after one crude acetone having been alkali-treated or while an alkali or an aqueous solution thereof being added to the crude acetone, by mixing the aqueous rectification residue with an alkali, neutralizing the mixture to a pH of 4 to 9, and then subjecting the resulting mixture to distillation to obtain acetone as a distillate.

Abstract: A process for purifying caprolactame by continuous and/or discontinuous (or atch) vacuum distillation comprises a first stage fast vacuum distillation of the raw caprolactame possibly in the presence of an alkaline and/or alkaline-earth hydroxide, a second stage consisting of a vacuum rectification distillation of the caprolactame obtained in the first stage and a third stage consisting of the fast vacuum distillation of the caprolactame yielded from the second stage, in the presence of an alkaline and/or alkaline-earth hydroxide. The hydroxide amount in the third and possibly the first stage distillation as well varies from 0.05 to 5% preferably from 0.1% to 1%.

Abstract: The invention relates to a process for the production of .epsilon.-caprolactone having a purity of 99.9% and increased color and storage stability which comprises feeding .epsilon.-caprolactone, which has been made by reacting cyclohexanone with a solution of a percarboxylic acid, into a first distillation unit, operating at 0.1 to 500 mbars and drawing off as the top product a mixture consisting of .epsilon.-caprolactone and lower-boiling impurities, feeding the bottom product of said first distillation unit into a second distillation unit, operating at 0.1 to 500 mbars and then drawing off the pure .epsilon.-caprolactone as the top product. The .epsilon.-caprolactone is useful as an intermediate for the production of known useful compounds such as polyesterols which are subsequently converted to polyurethanes.

Abstract: The invention relates to a process for the isolation of chloroacetaldehyde which is obtained as a by-product during the synthesis of acetaldehyde from ethylene and air in an aqueous palladium/cupric chloride solution by the 2-stage process. The mixture to be worked-up to chloroacetaldehyde is taken from the acetaldehyde distillation column and transferred to a distillation and extraction system, where it is fractionally condensed. The chloroacetaldehyde-containing fraction is extracted with water and the aqueous extract is subjected to purification distillation.

Abstract: A process for isolating butadiene, with the aid of a selective solvent, from a C.sub.4 -hydrocarbon mixture which contains butadiene and small amounts of styrene and may contain oxygen, hydrocarbons more soluble than butadiene in the selective solvent and hydrocarbons less soluble than butadiene in the selective solvent, in which process the C.sub.4 -hydrocarbon mixture is separated by extractive distillation into a distillate which contains the less soluble hydrocarbons, a stream of butadiene and a stream containing the more soluble hydrocarbons, and in which a mixture of styrene and C.sub.4 -hydrocarbons is removed from the C.sub.4 -hydrocarbon mixture in a distillation zone upstream of the extractive distillation, the top product of the said distillation zone being fed to the extractive distillation.

Abstract: Disclosed is a method and apparatus for the concentration of a solution of a "dissolved" material in a "solvent" without the input of any outside heat and by the furnishing of only work, the latter having a value close to the theoretical work of unmixing.

Abstract: Indene is separated from close boiling, olefinically unsaturated alkylaromatic compounds by extractive distillation. For example, indene is separated from trans-.beta.-methylstyrene, and from 2-, 3- and 4-methylstyrene by extractive distillation using 1-methyl-2-pyrrolidone as the extracting agent.

Abstract: Residual products obtained in the catalytic dehydration of alpha-methylbenzyl alcohol are treated to recover monomeric styrene values by a process which comprises fractionally distilling the residual products in two stages under different temperature and time conditions.