Abstract: In an apparatus for treatment of an ammoniacal waste liquid comprising a reaction tank for effecting a decomposition reaction of fixed ammonia by adding a calcium series alkali so as to obtain a reaction product comprising free ammonia and a calcium salt, a solid-liquid separator for effecting separation of the calcium salt so as to obtain a separated liquid, a distillation column for steam-stripping of the free ammonia from the separated liquid, and a pipe passage connecting consecutively said reaction tank, said separator and said distillation column, the improvement comprising a heat aging tank interposed in the pipe passage between the solid-liquid separator and the distillation column so that the calcium salt present in a dissolved state in the separated liquid may be separated out and aged in the aging tank where the liquid is raised to the temperature at the top of the distillation column, thus preventing blocking in the distillation column.

Abstract: Pure acetone is recovered from a crude acetone vapor fraction removed overhead from a first column separating phenol and higher boilers as a bottom fraction from a cumene hydroperoxide cleavage reaction product by partially condensing the crude acetone fraction, returning the condensed portion of the crude acetone fraction to the first column as reflux, feeding the remaining portion as a vapor to an intermediate point in a second distillation column to which there is also fed continuously at a point above the acetone feedpoint a dilute aqueous solution of an alkali, removing from the base of the second column a residue fraction comprising compounds boiling above acetone, removing from a point in the second column intermediate; between the alkali feedpoint and the top of the column as a liquid sidedraw fraction pure acetone having a permanganate time (PT) greater than 4 hours, and removing from the top of the second column as a vapor fraction acetone having a PT less than that of the sidedraw fraction, condens

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: The present invention relates to a process for removing cyanides from a crude acetonitrile stream. Caustic and formaldehyde are added to an aqueous acetonitrile stream that contains cyanide. The formaldehyde "kills" the cyanides and provides a waste stream that can be conveniently disposed of.

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: 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: Process for purifying crude ethanol, whether produced by fermentation or by the synthetic route, to produce a pure ethanol-water azeotrope. The process uses only two distillation columns for fermentation ethanol and only three columns for synthetic ethanol because the latter has diethyl ether as impurity. The inventive concept lies in the design and specification of the columns and the specific distillation conditions which enable each of the impurities in ethanol to be reduced below 1 ppm. Ethanol of such purity is most desirable when used for potable or pharmaceutical purposes. The crude ethanol is fed into a first column and water is separately fed there as well, a side stream of purified aqueous ethanol is withdrawn from the first column and fed to a rectification column where a substantially pure ethanol-water azeotrope is withdrawn as a side stream. The points of introduction and removal of the respective streams to and from the columns are critical for a successful operation and product recovery.

Abstract: Crude acetonitrile containing impurities such as hydrogen cyanide, allyl alcohol, oxazole and water is purified by at least one of the following processes (i) through (iv). (i) Process of removing hydrogen cyanide wherein crude acetonitrile is treated with an alkali in an amount sufficient to convert a substantial part of the free hydrogen cyanide present in the crude acetonitrile to an alkali metal cyanide but insufficient to convert a substantial part of the combined hydrogen cyanide present in the crude acetonitrile to an alkali metal cyanide; and then, the so obtained reaction mixture is subjected to distillation under reduced pressure.

Abstract: Crude liquid polyether-polyols containing an alkaline catalyst are purified by the steps of:neutralizing said crude liquid polyether-polyol with a mineral acid having a dissociation constant of greater than 10.sup.-3 at 25.degree. C.distilling off water from said liquid, and filtering the same. The improvement resides in the step of adding a hydrate of a metal salt of said mineral acid to the liquid polyether-polyol at a stage before the distillation step for promoting the crystal growth of a salt formed from said alkaline catalyst by the neutralization.

Abstract: A process for the purification of olefine oxides by subjecting a mixture containing the olefine oxides to distillation in a distillation column in the presence of a small amount of water in order to obtain olefine oxide as the distillate. A fraction of the down-flow liquid is withdrawn from the column and the withdrawn fraction is subjected to decantation, so as to separate off an aqueous phase which is discarded, and an organic phase. The organic phase is returned to the column at a point located below the withdrawal point.

Abstract: Disclosed is an improved method of forming polyol (allyl carbonate) monomers. In the disclosed method, the organic by-products as diallyl carbonate and unreacted reagents as allyl alcohol are separated from the brine and wash water derived aqueous phase and returned to the allyl carbonate synthesis reaction. The aqueous phase is further separated to recover allyl alcohol therefrom, which is returned to the allyl carbonate synthesis reactor as an azeotrope.

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: A process for obtaining colorless and stable isophorone is characterized by distilling a raw synthesis mixture to remove alkaline agents, acetone, and a major portion of the water which is present, thermally treating the distilled mixture with an acidic ion-exchanging resin, neutralizing the effluent following said thermal treatment with an excess of an alkaline agent, adding water in a volume sufficient to dissolve any salts which may have formed, then again, neutralizing the now alkaline mixture wherein the pH of the resultant mixture is between 6.5 and 7, washing the mixture in water by decantation, and distilling the mixture under reduced pressure.

Abstract: Water containing dissolved compounds is preheated, and is then pressurized in stages of water pressure, while receiving a quantum of steam. Scale-forming compounds in the water are thermally precipitated, and clarified post-thermal water is formed. This is flash vaporized in stages corresponding to the stages of water pressure, and the flashed vapors are compressed to form each said quantum of steam. Alternately, the flashed vapors themselves comprise each said quantum of steam, by being induced into the water as it flows through an eductor means. Flash-cooled, post-thermal water, substantially devoid of scale-forming compounds, is employed as such, or more generally is evaporated to form fresh water and an end concentrate of dissolved compounds.

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: Concentrated acetic acid of 95 to 100 weight percent concentration containing both ionic and coordinate bromine can be successfully purified to a bromine content of less than 3 ppm by the sequential steps of catalytic hydrogenation, contacting the resulting acetic acid with alkali metal hydroxide, carbonate or bicarbonate, and then distilling acetic acid from the alkali metal.

Abstract: Ethylene glycol is recovered from spent glycol containing impurities, such as dimethyl terephthalate, by subjecting the spent glycol to a sequential flash evaporation-distillation or distillation-flash evaporation-distillation procedure. Dimethyl terephthalate impurities are rendered non-volatile by the addition of a small amount of alkali metal hydroxide prior to flash evaporation. Dewatering of spent glycol and separation of ethylene glycol from impurities rendered non-volatile by alkali metal hydroxide is also performed in one or two distillation steps. Sufficient ethylene glycol is recovered to make use of flash evaporation an optional step.

Abstract: Silicate fouling on the reboilers and trays and the distillation train used for the production of dihydric alcohols is arrested by the addition of caustic to the feed stream.

Abstract: A process for reducing the chemical oxygen demand of water removed from a mixture of crude tetrahydrofuran and water, said process comprising contacting said mixture in the vapor phase with a dilute sodium hydroxide solution, then optionally contacting the tetrahydrofuran-water mixture after condensation with a concentrated sodium hydroxide solution and separating water from the thus treated mixture, said water having reduced chemical oxygen demand over water that is removed from said mixture merely by distillation.

Abstract: The formaldehyde hydrazone of UDMH can be removed from an aqueous solution f UDMH by codistillation with a hydrocarbon or other solvent which is inert to both acidic or basis mediums. The solvent can then be recovered from the hydrazone solution by washing with an acid solution and the solvent can be reused.

Abstract: Treatment of liquid waste contaminated with volatile radioactive substances under both acid and alkaline conditions in a single unit consisting of a still with connecting superposed column of spaced bubble-cap type plates. The pH of the liquid in the still is different from the pH of liquid reflux in an intermediate group of plates in the column facilitating scrubbing out of the volatile radioactive substances. An intermediate loop for circulating liquid from the bottom plate of the intermediate group to the top plate of the intermediate group at controlled pH is provided for this purpose.

Abstract: A process for extracting essentially pure unsymmetrical dimethyl hydrazine UDMH) from a solution containing UDMH, water, and other volatiles and non-volatiles, comprises charging a distillation stillpot with the UDMH solution, mixing into the solution sufficient caustic sodium hydroxide so as to cause the solution to separate into a two layer system, mixing isopropanol into the two layer system, and distilling off the essentially pure UDMH distillate.

Abstract: The present invention refers to a process for the purification of acetonitrile from crude acetonitrile or mixtures containing the same, which comprises the following operations:(a) transformation of hydrogen cyanide and acrylonitrile into compounds of higher molecular weight,(b) removal of most of the water in an azeotropic distillation column, and(c) separation of acetonitrile from the compounds of higher molecular weight and residual water in rectifying columns.

Abstract: A water purification process is described for the removal of ammonia and optionally one or more acid gases from waste waters such as coke-plant or coal conversion waste waters. The process involves adding lime to these waste waters in amounts sufficient to react with fixed ammonia salts present in the waste water and to enable substantially all of the ammonia to be evolved upon distillation, adding a threshold amount of a scale inhibitor compound chosen from the class of certain organic phosphonates and subjecting the thus treated waste water to distillation to remove substantially all of the ammonia and acid gases present from the waste water. Preferably, this process is achieved by two separate and successive distillations. In this preferred process, the first distillation substantially reduces the amount of the acid gases and free ammonia. In the second distillation, the amount of fixed ammonia is substantially reduced.

Abstract: A water purification process is described for the removal of ammonia and optionally one or more acid gases from waste waters such as coke-plant or coal conversion waste waters. The process involves adding lime to these waste waters in amounts sufficient to react with fixed ammonia salts present in the waste water and to enable substantial amounts of the ammonia to be evolved upon distillation, adding a threshold amount of a scale inhibitor compound chosen from the class of certain organic phosphonates and subjecting the thus treated waste water to distillation to remove substantial amounts of the ammonia and acid gases present from the waste water. Preferably, this process is achieved by two separate and successive distillations. In this preferred process, the first distillation substantially reduces the amount of the acid gases and free ammonia and is conducted at a pH of more than 9. In the second distillation, the amount of fixed ammonia is substantially reduced.

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: Recovery of the chemical components of a cellulosic organic solvent regenerating solution containing a dialkylacylamide, water, nitrous and nitric acid. The process comprises neutralizing the solution to form the metal salts of nitrous and nitric acid, distilling the neutralized solution to remove and recover the water and dialkylacylamide solvent and pyrolyzing the metal salts in the presence of oxygen to remove and recover nitrogen dioxide gas. The process results in substantially total recovery of the process chemicals.

Abstract: A process is provided for producing ultra-pure propionic acid, i.e., acid containing less than 20 parts by weight of iodine per billion parts by weight of acid, wherein crude acid containing water and iodine contaminants is distilled in a single distillation zone and no waste streams requiring treatment or disposal are obtained.

Abstract: Styrene is inhibited against polymerization during the distillation thereof by incorporating therein, in an amount sufficient to inhibit polymerization thereof, the dinitrophenol solution recovered from styrene still residues or tars resulting from the distillation of styrene in the presence of dinitrophenol. The recovered dinitrophenol solution is a more effective polymerization inhibitor than dinitrophenol per se.

Abstract: 1,1,1,3,3,3-Hexafluoroisopropyl trifluoroacetate is separated from a crude reaction mixture by adding fluorotrichloromethane to said mixture and subjecting the resulting composition to fractional distillation to fractionally distill an azeotrope consisting of said 1,1,1,3,3,3-hexafluoroisopropyl trifluoroacetate and said fluorotrichloromethane from the crude mixture.

Abstract: A recovery method by means of which an antimony compound is separated from polyester still bottoms. If desired, the method can be employed so as to recover in usable form, the antimony compound, and the monomers polymerized to produce the polyester.

Abstract: A process for recovering and separating substantially pure ethylphenol and substantially pure diethylbenzene from a mixture resulting from the decomposition of diethylbenzene monohydroperoxide and consisting essentially of diethylbenzene, ethylphenol and oxygenated by-products thereof, said process comprising distilling said mixture in a first distillation step operated under reduced pressure to separate a distillate comprising essentially diethylbenzene from a first residue comprising ethylphenol and the oxygenated by-products of said mixture, withdrawing said residue and distilling said first residue in a second distillation step operated under reduced pressure to separate a distillate consisting essentially of ethylphenol from a second residue containing from 30 to 40 mole % of ethylphenol in admixture with said oxygenated by-products, withdrawing said second residue and mixing it with the distillate from the first distillation step, treating the resulting mixture with an aqueous alkaline solution to form

Abstract: A crude alcohol-containing mixture comprising a saturated aliphatic alcohol of not more than three carbon atoms and associated impurities is processed in a three-tower distillation system to permit recovery of the desired alcohol product in highly concentrated and purified form. In the first tower the crude feed is subjected to extractive distillation with water to remove substantially all the impurities overhead. An aqueous bottoms stream from the first tower containing 5 to 10 wt.% alcohol and only minor amount of impurities is fed to the second tower where the alcohol product is concentrated and recovered. Overhead and intermediate purge streams containing low boiling and hgh boiling impurities are removed from the second tower and are fed to the third tower along with the overhead from the first tower. Stripped aqueous effluent is withdrawn from the bottom of the second tower and is recycled in part to the first tower.

Abstract: Pure C.sub.1 -C.sub.3 alkanols are prepared from crude water containing alcohols in a continuous distillation process which includes an extractive distillation zone into which water and crude alcohols are introduced and from which is removed an impurities stream and a dilute aqueous alcohol stream; an alcohol concentration zone into which is introduced a dilute alcohol stream from the extractive distillation zone from which is withdrawn pure concentrated alcohols, a low boiling impurities stream and a high boiling impurities stream; and an impurities concentration zone into which is introduced the impurities stream from the extractive distillation zone and the high and low boiling impurities streams from the alcohol concentration zone from which is withdrawn high and low boiling impurities and an alcohol containing stream which is recycled to the extractive distillation zone with the crude alcohols.

Abstract: The present invention relates to the recovery of N,N-dimethylacetamide from a mixture containing N,N-dimethylacetamide and acetic acid. Potassium hydroxide is added to the mixture to neutralize the acetic acid and form potassium acetate having a low solubility in N,N-dimethylacetamide and a high affinity for water. The water concentration is adjusted to a desired range and a water non-solvent such as benzene is added to effect separation of an aqueous solution of potassium acetate from the dimethylacetamide as two distinct phases. The phases are then separated and the dimethylacetamide removed from the solvent phase by distillation.