Abstract: A process for the substantially complete removal of acid gases and ammonia from aqueous solutions is disclosed, which comprises a two stage distillation operation wherein the pressure in the first distillation stage is substantially less than the pressure in the second stage, the ammonia concentration in this stage decreases downwardly so that an aqueous bottoms stream has a pH less than 8, this aqueous bottoms stream is treated with alkali and then distilled in the second stage. A portion of the aqueous bottoms can be vaporized by indirect heat exchange with vapors evolving from the second stage. The improvement lies in adding ammonia to the overhead vapor from the first stage to reduce corrosion of the condenser and preferably, the amount of vapor condensed is controlled to further minimize corrosion.

Abstract: A process for distilling ammoniacal solutions is disclosed comprising the utilization of two distillation columns operating at different pressures, the ammoniacal solution to be distilled being sent--after being mixed with the ammoniacal vapors flowing from the top of the column operating at the lower pressure--to the column operating at the higher pressure, from the bottom of which the partially distilled ammoniacal solution is sent to the column operating at the lower pressure; the liquid ammonia being recovered at the top of the column operating at the higher pressure while the residual ammoniacal solution is withdrawn from the bottom of the column operating at the lower pressure.

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: A process is described for the isolation of pyrocatechol and hydroquinone from mixtures containing the same, and phenol and higher boiling accompanying substances. The mixture can be one obtained by reacting phenol with a peroxidic hydroxylating agent and removing some of the phenol and the substances which have a lower boiling point than phenol. The mixture is subjected to a first rectification in which phenol and substances which have a boiling point between phenol and pyrocatechol are obtained overhead to leave behind a bottom product containing pyrocatechol and hydroquinone. The bottom product is subjected to a second rectification in which the pyrocatechol is obtained overhead to leave behind a bottom product containing hydroquinone and higher boiling accompanying substances. This bottom product is fed to a concentrating unit in which hydroquinone is evaporated overhead to leave behind high boiling accompanying substances as residue.

Abstract: An improved process of distilling a cyclohexanone-rich overhead stream in a first still from a feed mixture comprising cyclohexanone, phenol and cyclohexanol of the type wherein a cyclohexanone-rich stream is withdrawn as a part of an overheads condensate from the first still and a phenol-rich stream is withdrawn as a part of a reboiled bottom stream from the first still. The improvement includes withdrawing a side stream substantially free of phenol from above the point where the feed mixture is fed to the first column and separating the side stream in a second still into a second cyclohexanone-rich overhead stream and a bottom stream containing cyclohexanone and cyclohexanol. The second cyclohexanone-rich stream may be returned to the first still.

Abstract: The recovery of alcohol from fermentation liquors is accomplished by the evaporation of the liquor feed and simultaneous rectification of the volatile component. Evaporation of the liquor feed can be accomplished by a single flash evaporation or multiple effect evaporation combined with the flash evaporation in which the flash evaporator is one effect of the multiple effect evaporator. A concentrated alcohol component is recovered along with a concentrated residue useful as a fertilizer or animal feed supplement.

Abstract: Process for isolating methyl tert-butyl ether contained in the reaction product of methanol with a C.sub.4 hydrocarbon cut containing isobutene, comprising fractionating said reaction product by introducing it at an intermediate point of a distillation zone, recovering methyl tert-butyl ether at the bottom thereof and, at the top thereof, a mixture of C.sub.4 hydrocarbons with methanol which is washed with water and condensed and wherefrom is separated a condensed C.sub.4 hydrocarbon fraction, a portion of which is fed back as reflux to the top of the distillation zone and another portion discharged, and separating the remaining water-methanol mixture by distillation.

Abstract: A normally liquid hydrocarbon having a minimum boiling point of about 425.degree. F. is utilized to provide the liquid seal in a vacuum pump which intakes a gaseous light ends stream resulting from a process for the production of ethyl acrylate by the reaction of ethylene with acrylic acid in the presence of a sulfuric acid catalyst. Upon contact in the vacuum pump, the gaseous light ends are partially absorbed into the normally liquid hydrocarbon, with the normally liquid hydrocarbon being recovered by fractionation.

Abstract: A process for recovering pure benzene from hydrocarbon mixtures containing the same and non-aromatic compounds which are gaseous and difficultly condensible is described in which the feedstock is fed to an initial distillation column operated at atmospheric or sub-atmospheric pressure. Overhead comprising benzene and non-aromatics is obtained and a portion thereof condensed. The condensible material is in part returned to the distillation column and in part subjected to extractive distillation to recover pure benzene. Those components which did not condense, i.e. the non-condensible and difficultly condensible components and entrained aromatics are fed to a reflux vessel such as a scrubber, stripper, or the like for recovery of any benzene or other valuable components which might be soluble in a selective solvent and used for such recovery. The selective solvent can be the same solvent used for the extractive distillation.

Abstract: Formic acid is produced in a continuous process by hydrolyzing methyl formate with water at high temperature and pressure in the presence of a formic acid catalyst. Methanol is also formed. The reesterification of the reaction products to methyl formate (a reaction favored by high temperatures) is minimized by flashing the reaction product at relatively low pressure and temperature and thereafter distilling the residual liquid under vacuum. This procedure separates the methyl alcohol from the formic acid with a minimum contact time and at a low temperature which does not favor the reesterification reaction. The flashed vapor, primarily unreacted methyl formate, is recycled to the reaction zone. High purity formic acid, i.e., 85%, is obtained by subjecting the bottom from the vacuum distillation to a second distillation step. The distillate from the vacuum distillation is distilled to separate residual methyl formate for recycle from the co-product methyl alcohol.

Abstract: 2,2-Dichloro-5-methyl-1,1,1-trifluorohex-4-ene, an intermediate in the synthesis of pyrethroid insecticides, is obtained by continuous distillation, preferably under sub-atmospheric pressure, of a mixture of 5-methyl-2,2,4-trichloro-1,1,1-trifluorohexane, dimethylformamide and lithium bromide, precipitating the chlorofluorocarbons from the distillate with water and separating the desired product from starting material by a further distillation.

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.

Abstract: A process is described for the removal of acid gases and ammonia from dilute aqueous solutions. This is achieved by two separate and successive distillations. In the first distillation, substantially all of the acid gases and free ammonia are removed. In the second distillation, substantially all of the fixed ammonia is removed. Exemplary aqueous solutions are waste waters from coke oven and coal conversion plants.

Abstract: In an apparatus for distilling liquids an improvement is provided wherein distillate is heated within an auxiliary reboiler for further removal of volatile impurities, with the operating environment of the auxiliary reboiler being isolated from the main ambient atmosphere of the apparatus so that evaporated impurities can be vented without recontaminating the distillate or impairing the efficiency of the apparatus. Countercurrent flow of distillate and vapors within the auxiliary reboiler produces enhanced purity of the distillate.

Abstract: Disclosed herein is a process for recovering a phosphate ester type hydraulic fluid from a waste liquid containing water, organic solvents and other impurities, such as polychlorinated biphenyls (PCB). After filtering to remove particulate matter, a heavy fraction separated from the waste liquid and consisting primarily of the hydraulic fluid is first subjected to a distillation step. A substantial portion of the PCB is removed as overhead from the distillation step and the bottoms containing the hydraulic fluid is subsequently evaporated, preferably in a thin film evaporator. The overhead from the evaporation step is condensed to recover the hydraulic fluid.

Abstract: Water-containing glycol is heated first at atmospheric or superatmospheric pressure to partially remove water and concentrate the glycol and is then heated at subatmospheric pressure to further concentrate the glycol.

Abstract: An improved process for recovering isobutylene contained in a mixture of hydrocarbons having four carbon atoms by selective extraction with an aqueous solution of sulfuric acid of a concentration of about 50 wt. % followed by separating the isobutylene-rich sulfuric acid extract by a first flash distillation of the extract and by a second physical separation of the isobutylene-enriched extract from said flashing step (which the latter physical separation is preferaby a second flash distillation at a temperature which is higher than the first and is at 75.degree. C. or less, and wherein said first flash distillation is between 10.degree. and 60.degree. C. and both distillations are preferably at a pressure between 0.5 and 1.5 bars absolute to give an isobutylene purity greater than 99.5%).

Abstract: A process for separating, by means of a selective solvent, a mixture of C.sub.

Abstract: Crude phenol is recovered from CHP reaction products by continuously feeding to a main column separating in its uppermost section phenol from crude acetone, this fraction being removed overhead, and in the lower section crude phenol from higher boilers, including acetophenone and carbinol, the crude phenol being removed as a sidestream fraction from the main column at a point in the column above the feed-point wherein the total concentration of acetophenone plus carbinol is less than 1,000 ppm and the higher boiling compounds being removed as a base fraction.

Abstract: The invention provides unusally efficient distillation apparatus configured into a compact structure which conserves material in its construction and power consumption in its operation. The present structure particularly provides horizontally disposed flash effect distillation chambers coupled "back-to-back" across a common wall, the chambers being operable as a distillation system for water purification and/or solute concentration or as a sub-system in multi-effect distillation systems.

Abstract: A process for the production of alkylaromatic hydrocarbons by the alkylation of benzene wherein the alkylation zone effluent is fractionated to form a bottoms stream comprising benzene, the alkylaromatic hydrocarbon and a light paraffin. The light paraffin is then removed from the bottoms stream in a first recycle column which produces a recycled overhead stream comprising the paraffin and benzene. The bottoms stream of the first recycle column is separated in a second recycle column, which is operated at about the same bottom temperature but a lower pressure than the first recycle column. The benzene-rich overhead stream of the second recycle column is preferably recycled to the alkylation zone.

Abstract: Recovery of the chemical components of a cellulosic organic solvent regenerating solution containing a dialkylacylamide, a lower aliphatic monohydric alcohol, a nitrite of the alcohol and nitric acid. The process comprises distilling the solution to remove the alcohol nitrite and alcohol, leaving the dialkylacylamide and nitric acid, recovering the alcohol, hydrolyzing to convert the alcohol nitrite to the alcohol and nitrous acid, neutralizing the nitric and nitrous acid with an alkali or alkaline earth metal oxide or hydroxide and distilling the solution to remove water and to separate and recover the remaining alcohol, the dialkylacylamide and the nitrate and nitrite salts. The nitrite and nitrate salts are converted by pyrolysis to nitrogen dioxide. The process results in substantially total recovery of the process chemicals.

Abstract: A mixture of methylethylsulfone and at least one compound from the group including methylethylketone, acetone, and tetrahydrofuran is employed as a selective solvent in extractive distillation process for separation of diolefins from olefins.

Abstract: A process for simultaneously generating power and recovering potable water from a source of salinous water -- e.g. sea water. Salinous water, from a locus which is proximate to the surface thereof and at a relatively high temperature -- e.g. about 85.degree. F. -- is exposed to radiant solar energy to increase significantly the temperature thereof -- e.g. to a level of at least about 135.degree. F. The heated water is introduced into a plurality of flash separation zones, each succeeding one of which is maintained at a lower subatmospheric pressure than the preceding zone, to provide substantially non-salinous vaporous phases. The salinous liquid phase is introduced in series through the plurality of flash zones. The vapor phases are passed through separate, individual turbines, or are introduced into different stages of a multi-stage turbine, from the resulting motion of which power is generated.

Abstract: A fractional distillation method of separating diacetoxybutene isomers from a reaction mixture produced from the reaction of butadiene, acetic acid and molecular oxygen comprises employing a series of at least two distillation towers, one of said towers being used for distillation of water and acetic acid under a pressure of 30 - 250 Torr and a tower bottom temperature of 190.degree. - 120.degree. C and the other being used for separation of high boiling point materials under a pressure of 2 - 100 Torr and a tower bottom temperature of 190.degree. - 120.degree. C, the temperature of all tower bottoms being from 190.degree. - 120.degree. C.

Abstract: A process for simultaneously generating power and recovering potable water from a source of salinous water -- e.g. sea water. Salinous water, from a locus which is proximate to the surface thereof and at a relatively high temperature -- e.g. about 85.degree. F. -- is exposed to radiant solar energy to increase significantly the temperature thereof -- e.g. to a level of at least about 135.degree. F. The heated water is introduced into a plurality of flash separation zones, each succeeding one of which is maintained at a lower subatmospheric pressure than the preceding zone, to provide substantially non-salinous vapor phases. The salinous liquid phase is introduced in series through the plurality of flash zones. The vapor phases are passed through separate, individual turbines, or into different stages of a multiple-stage turbine, from the resulting motion of which power is generated.

Abstract: A process for simultaneously generating power and recovering potable water from a source of salinous water -- e.g. sea water. Salinous water, from a locus which is proximate to the surface of the source and at a relatively high temperature -- e.g. about 85.degree. F. -- is exposed to radiant solar energy to increase significantly the temperature thereof -- e.g. to a level of at least about 135.degree. F. The heated water is introduced into a plurality of flash separation zones, each succeeding one of which is maintained at a lower subatomospheric pressure than the preceding zone, to provide substantially non-salinous vapor phases. The salinous liquid phase is introduced in series through the plurality of flash zones. The vapor phases are utilized to vaporize hydrocarbons, in separate vaporizers, and the hydrocarbon vapors are passed through separate, individual turbines, or are introduced into different stages of a multi-stage turbine, from the resulting motion of which power is generated.

Abstract: Dilute sulfuric acid contaminated with acetic acid and hydrogen chloride is purified with the resultant formation of concentrated sulfuric acid and acetic acid. To this end, the contaminated sulfuric acid is heated in a first step to at most 60.degree. C under 25-30 mm Hg so as to expel all of the hydrogen chloride together with minor proportions of acetic acid and water. In a second step, the sulfuric acid is heated to at most 165.degree. C under 20-25 mm Hg so as to distil off the bulk of acetic acid together with water. In a third step, the sulfuric acid is cooled down to 60.degree.-90.degree. C, diluted with 10-30 wieght % of water with agitation and while cooling is continued. Following this, the sulfuric acid is heated to 160.degree.-165.degree. C under 20-25 mm Hg and thereby freed from the water and residual acetic acid.

Abstract: Process for the separation of trioxane from aqueous solutions containing it together with formaldehyde, which comprises subjecting the said solutions to evaporation at temperatures of 100.degree. C or lower, at pressures lower than atmospheric, and with residence times of less than 1 minute under the evaporation conditions, with vaporization of a quantity of from about 5 to about 15% by weight of the solution introduced, and recovering the trioxane from the products evaporated in this way.

Abstract: An improvement is described on a process for recovery of butadiene from a C.sub.4 hydrocarbon mixture additionally containing minor amounts of C.sub.5 saturated and unsaturated hydrocarbons, said hydrocarbon mixture being obtained as the overhead product of an initial hydrocarbon fractionation employed to separate larger quantities of C.sub.5 and heavier hydrocarbons from the hydrocarbon mixture, wherein the hydrocarbon mixture is subject to extractive distillation in the presence of a polar solvent e.g. acetonitrile, in which butadiene is separated from the fat solvent bottoms of extractive distillation by sequential low pressure flashing and stripping, followed by compression of the combined vapors of flashing and stripping with part of the compressed vapors being recycled as reboiled vapor to the extractive distillation and the remainder being again stripped at a higher pressure to recover butadiene therefrom. In this improved process, butadiene purification problems associated with carry over of C.sub.

Abstract: Aqueous solutions of methane sulfonic acid are dehydrated and purified in a two-step fractionation process.

Abstract: The overhead stream of a deisobutanizer in an HF-alkylation plant is extracted with HF to produce a stream containing isobutane, HF and ethyl fluoride, which in turn is fractionated under a pressure of about 150 to 300 psig. The bottoms stream of this fractionation, then, is fractionated under a pressure of 50 to 145 psig to produce a relatively pure ethyl fluoride overhead stream and a relatively pure HF bottoms stream.

Abstract: A system for softening of water in a manner to minimize heat requirements in the water softener unit of the system. Flashed water vapor from a flash box coupled to the downstream end of the softener unit is used to preheat incoming hard feed water by directly contacting the feed water in respective preheating chambers upstream of the softener unit. The system is suitable for use in a distillation plant to produce potable water.

Abstract: 2,5 DIOXO-1-OXA-2-PHOSPHOLANES OF THE GENERAL FORMULA: ##STR1## in which R.sup.1 stands for an alkyl radical having from 1 to 4 carbon atoms, or a phenyl radical, and R.sup.2 and R.sup.3 each stand for hydrogen or CH.sub.3, are distillatively purified. To this end the respective crude compound is preheated to 120.degree. to 160.degree. C and fed to the head of a distilling column provided with a plurality of individually heatable trays maintained at temperatures increasing from the upper-most tray to the lowermost, the uppermost tray in the column being maintained at 120.degree. to 160.degree. C and the lowermost tray being maintained at 160.degree. to 200.degree. C, the pressure at the head of the column being 20 to 200 mm Hg, preferably 50 to 120 mm Hg; an inert gas preheated to 160.degree. to 200.degree.

Abstract: Glycide is prepared by reacting allyl alcohol with hydrogen peroxide in the presence of a tungsten compound as a catalysts the excess allyl alcohol and the greatest part of the water distilled off, the sump mixture obtained in the distillation is split at 110.degree.-220.degree. C. and 5 to 60 torr in a thin layer evaporator into a volatile portion which is predominantly glycide, high boiling by products and the residual part of the water and a sump portion of glycerine, polyglycerine and catalysts. The volatile liquid portion is broken into glycide, water and high boiling byproducts at 5 to 60 torr in a distillation apparatus directly connected to the thin layer evaporator.

Abstract: Hydrogen fluoride can be separated from an organic mixture of fluorinated C.sub.1 -C.sub.3 compounds and recovered for reuse by selectively absorbing the HF in a glycol in which the HF is soluble, but the fluorinated organic compound is substantially insoluble. If desired, HF can be obtained in anhydrous form.