Abstract: A distillation method for the purification of crude propylene oxide containing contaminating quantities of water and methanol by partially purifying the crude propylene oxide in a plural stage distillation zone to provide a vaporized overhead distillate propylene oxide fraction containing a minor contaminating amount of vaporized water, andpassing the propylene oxide vapor fraction through a drying chamber containing a porous hygroscopic solid absorbent to selectively absorb water vapor onto the absorbent,and liquefying and recovering the thus-dehydrated purified propylene oxide.

Abstract: A process to separate in a fractionation zone an admixture comprising phenol, alpha-methylstyrene and water to produce an alpha-methylstyrene stream containing a minimum of phenol. The pH of the overhead aqueous phase is adjusted with a base to greater than about 6.

Abstract: The present invention concerns a method for making energetic oxidizer salts and solutions thereof, and in particular relates to processes for making aqueous solutions of hydroxylammonium nitrate in high purity suitable for use in making liquid gun propellants. The present alcohol-free process yields high purity alcohol-free hydroxylammonium nitrate by neutralizing an aqueous nitric acid solution (20-70% wt./wt.) with an alcohol-free aqueous hydroxylamine solution at temperatures ranging from above -50.degree. C. to substantially less than ambient (20.degree. C.) to produce the desired alcohol-free aqueous hydroxylammonium nitrate solution in a usable concentration and in high purity. The process is economical, environmentally acceptable, and facile.

Abstract: The present invention relates to a process for purifying fatty acid amides, which contains the following process steps:neutralization of the fatty acid by addition of an aqueous alkaline solution andsubsequent distillation of the neutralized mixture.

Abstract: Diaminodiphenyl-compounds of the structure selected from: ##STR1## wherein R.sub.1 and R.sub.2 can be: H, --CH.sub.3, --C.sub.2 H.sub.5, --C.sub.3 H.sub.7, --C.sub.4 H.sub.9 or ##STR2## Y can be: C(CH.sub.3).sub.2, ##STR3## n=0; 1. are purified by distilling the crude product obtained under vacuum in one step, in the presence of one or more alkaline bases.

Abstract: A process for recovering waste liquid from the distillation of fermented rice liquor. After filtration of the waste liquid, the residue can be recovered as dry feed, and the filtrate which contains about 4-5% crude protein, 1% starch and 92 wt. % water is first concentrated to lower the water content to about 70-80 wt. %. The filtrate is then dried with a spray dryer to produce nutritious dry feed while a suitable chelating agent such as magnesium hydroxide is used to prevent the clinging of the product on the wall of the dryer.

Abstract: Waste acetic acid, which is contaminated by nitrogen compounds and also by hardly hydrolyzable halogen compounds, is purified by adding a complex-forming metal or one of the compounds thereof and a basic compound. The resultant mixture is kept at a temperature between 25.degree. and 118.degree. C. over a period of time of 1 to 6 hours. Finally, purified acetic acid is removed from the mixture by distilling.

Abstract: A process for refining soap-containing crude polyol fatty-acid polyester reaction product, the process including one or more high-temperature refining treatments and as the first step in the refining process, contacting the crude reaction product with an acid to substantially convert the soap into its corresponding free fatty acids, and the subsequent step of substantially removing from the crude reaction product any salts therein prior to said one or more high-temperature refining treatments.

Abstract: Aqueous solutions which are contaminated by hydrogen sulfide, hydrogen cyanide, and ammonia are brought to a pH of about 3 or less after their formation and treated with an inert gas in a stripping column to remove the sulfide and cyanide. The pH of the solution is then increased to about 10 or more and the solution is again treated with an inert gas in a second stripping column to remove the ammonia.

Abstract: A process for removing organic compounds, including nitro-hydroxy-aromatic compounds and amines, from alkaline wastewater, and in particular from wastewater generated in the production of nitrobenzene, dinitrobenzene, nitrotoluene and dinitrotoluene. The process involves distilling the alkaline wastewater steam at or near atmospheric pressure until it is concentrated five to twenty-five fold. The distillate includes water, which may be discharged to the environment, subjected to biological treatment, or recycled for use in the production process; and volatile organics, which are phase separated from the aqueous portion of the distillate and which may be recycled to the crude product stream. The concentrated residue from the distillation may be incinerated or subjected to biological treatment.

Abstract: Separation of an aliphatic aminonitrile or an aliphatic diamine from a mixture containing the corresponding cyclic, aliphatic, mono-unsaturated amine by adding caustic compound to the mixture and then distilling the aminonitrile or the diamine at a temperature less than 170.degree. C. and at a pressure of less than 1 atmosphere.

Abstract: Micro-distillation apparatus is provided for analyzing acidic anions in which the acidic anion sample is placed in a lower elongated member in water containing an acidifying material, upon heating the acidic anion leaves the lower member as a gas, passing through a permeable membrane into an upper elongated member containing a material which converts the acidic anion to a salt and the salt is recovered for analysis. The micro-distillation apparatus is sized so that a number of samples can be heated in a small heating member, such as a hot block heater.

Abstract: A process for removing inorganic compounds from glycol recovery still bottoms resulting from the manufacture of poly(ethylene terephthalate), the novel process using a small amount of phosphoric acid to precipitate the antimony and then removing the titanium dioxide and antimony compound by a centrifuge. The novel process for removing the inorganic compounds from the recovery polyester bottoms includes the steps of distilling ethylene glycol from the spent glycol until the remaining bottoms have a solids concentration from about 15% to about 45%; adding phosphoric acid to the bottoms to form an antimony compound and removing the antimony and titanium precipitates from the bottoms by a centrifuge.

Abstract: When regenerating gas treating chemicals such as diethanolamine solution, the usual practice is to subject the chemicals to steam stripping. Ultimately such action is ineffective, and it is necessary to discard the chemicals. The waste chemical can be reclaimed by preheating the chemical in a countercurrent heat exchanger, in which heat is recovered from an already processed product; using a still to separate the preheated, partially vaporized chemical from the remainder of the chemicals; i.e. impurities or still bottoms; heating the still bottoms and recycling such bottoms for mixing with the partially vaporized chemical immediately upstream of the still; returning the separated vapor product from the still to the heat exchanger for heating feed chemical; and separating the thus partially condensed product in a separator to yield reclaimed gas treating chemical.

Abstract: Crude pentachloronitrobenzene containing hexachlorobenzene and small amounts of acids is treated in the molten state or in a mixture solution of nitrobenzene or chloronitrobenzenes with an inorganic basic substance and then subjected to a distillation under reduced pressure.

Abstract: Method of preparing para-cumylphenol including reacting an excess of phenol with alpha-methylstyrene by the slow addition of alpha-methylstyrene to a 50% to 200% molar excess of phenol at a temperature from about 80.degree. C. to about 90.degree. C. in the presence of an acid catalyst and thereafter maintaining the temperature at about 95.degree. to about 100.degree. C. to obtain a crude cumylphenol reaction product containing acid derived from the catalyst, and distilling the reaction product in the presence of an amount of base sufficient to neutralize the acid therein.

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

Abstract: High purity phenol is obtained from cleavage of cumene hydroperoxide by treating the crude phenol product stream in a first treatment zone with an amine, a coarse distillation to obtain an overhead stream comprising phenol, alpha-methyl styrene, cumene, and impurities, and steam distillation of the overhead stream in combination with addition of an amine to the steam distillation column for a second amine treatment step.

Abstract: A process for the production of pure dimethylether by feeding the dehydration product from a dimethylether-synthesis reactor into a distillation column for the production of pure dimethylether at defined trays of this column and withdrawal of pure dimethylether and a fraction containing contaminations at defined trays of the same column, whereby in addition washing liquids and bases can be added.

Abstract: A process for producing hydrazine containing at least 98 percent by weight of N.sub.2 H.sub.4 which admixes an aqueous solution of hydrazine with an alkali metal hydroxide to form a hydrazine solution having a N.sub.2 H.sub.4 concentration of at least 70 percent by weight. The molar ratio of alkali metal hydroxide to water is less than about 0.5:1. The concentrated hydrazine solution is distilled in a fractional distillation apparatus at an overhead vapor temperature below about 50.degree. C. and at a pressure of less than about 60 mm Hg.

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

Abstract: A process for treating naphthenic fractions with a caustic blend of sodium and potassium hydroxide, preflashing the naphthenic fraction to remove water and then flashing the dewatered fraction to remove the neutral oils and the materials that were not formed into the acid salts. The naphthenic salt mixture is then quenched and acidified so as to recover the naphthenic acids. Naphthenic acids recovered from the process of the present invention have acid numbers which are generally higher than the naphthenic acids heretofore produced from the corresponding feed streams. The process provides for the flashing of the water which otherwise would cause foaming and not permit the recovery of the acid salt for the enhanced separation of the naphthenic acids.

Abstract: A process for preventing the substantial decomposition of an alkyl sulfide compound at high temperatures comprising combining a non-reactive basic compound with the alkyl sulfide compound prior to subjecting the resultant mixture to the high temperatures.

Abstract: A process for obtaining available elements from seawater is described, which process includes two separation steps. The first separation step involved adjusting the pH of seawater to a low pH by adding a strong acid having sulphate ion, adding a strongly alkaline agent thereto in amount sufficient to provide a high pH and separating the precipitate formed thereby from the filtrate. The second separation step involves concentrating the filtrate, cooling the concentrated filtrate and separating a precipitate thereby formed. Each precipitate and each filtrate obtained in these steps has characteristic components and can be utilized for many purposes, for example, for food additives, as a solvent for paint, as combustion aids, or as alkaline agents for neutralization etc.

Abstract: A process for the purification of 1,1-diphenylethane with good fragrance quality. The product is produced by first subjecting the distillation residue from ethylbenzene production to distillation, then treating the distillate with sulfuric acid, separating the sulfuric acid phase, washing the oil phase with an alkali metal hydroxide solution and water, and subjecting the oil phase thus obtained to a second distillation.

Abstract: A process for removing volatile acids from aqueous solutions which involves steam stripping a volatile acid from an aqueous solution and contacting the vaporized acid with a reactable cation to form a salt of the acid. A preferred embodiment of apparatus comprises an elongated distillation column having therein a plurality of zones or stages wherein the volatile acid in the aqueous feed stream is vaporized by steam and then the vaporized acid is carried by the steam into a salt formation zone or stage to react with a reactable cation to form a salt of the acid.

Abstract: Distillation residues from the purification of caprolactam are worked up by heating in the presence of sodium hydroxide or potassium hydroxide and in the presence of a high-boiling hydrocarbon at from 250.degree. to 500.degree. C. and continuously removing the caprolactam.

Abstract: Excess amounts of a pure form of acrylonitrile are reacted with other reactants in the production of various compounds such as 2-acrylamido-2-methyl propane sulfonic acid. Accordingly, large amounts of acrylonitrile remain unreacted and present with other contaminants. The present invention is directed toward the purification of such unreacted acrylonitrile and the purified acrylonitrile obtained from such a purification process. The purification is carried out by treating the unreacted acrylonitrile with a base and removing salts formed. The treated material is fed to a heat exchanger which heats the material preferably under vacuum to about 120.degree. F. and provides a heated fluid material. This heated fluid material is pumped to a lower area of a distillation tower which is maintained under vacuum and includes a plurality of distillation trays.

Abstract: Ultrapure or anhydrous hydrazine is produced in a process which comprises distilling aqueous solutions of hydrazine having at least 70 percent by weight of N.sub.2 H.sub.4 at pressures below about 20 millimeters. Aqueous solutions of hydrazine are dehydrated with solid inorganic compounds such as alkali metal hydroxides which are essentially carbon-free. The concentrated hydrazine solution is then distilled at reduced pressures and temperatures which minimize the hazardous conditions present when using processes of the prior art. Monopropellant hydrazine suitable for use in spacecraft engines can be produced having a N.sub.2 H.sub.4 concentration of at least 99.5 percent and less than 5 parts per million of volatile carbonaceous materials.

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: This invention is a process for purifying crude acetone obtained by cleavage of cumene hydroperoxide, said crude acetone containing aldehyde impurities and appreciable amounts of unreacted cumene, by fractionally distilling the acetone in a multiple plate distillation column, said process comprising: continuously feeding crude acetone; continuously feeding a dilute aqueous solution of an alkaline material at a point above the crude acetone feed point; and controlling the temperature profile of the column by adjusting the amount of liquid acetone removed in step (c) to maintain a preselected temperature on a plate in the region between the crude acetone feed point and the alkaline material feed point.

Abstract: A method for removing impurities from caprolactam is disclosed. The method comprises the sequential steps of treating the impure caprolactam with phosphorus pentoxide so that the impurities react therewith to form high boiling species and then distilling the so treated impure lactam to recover substantially pure caprolactam as overhead, with the impurities remaining as bottoms.

Abstract: A method is disclosed for reducing alkali metal chlorate impurities in an aqueous alkali metal hydroxide solution by heating a mixture of the alkali metal hydroxide solution with a hydroxycarboxylic acid or a salt thereof at temperature above about 125.degree. C. and for a period of time sufficient to substantially eliminate the chlorate, the hydroxycarboxylic acid or salt thereof being substantially non-volatile at the heating temperature.

Abstract: An improved process for purification of glycerol obtained from natural sources comprising alkalizing a glycerol-containing crude mixture in the presence of air for oxidation, evaporating the mixture in a thin-layer evaporator with redistillation of the residue, rectification and reevaporation in a packed column characterized by low-pressure-loss plates with a falling-film evaporator designed for internal and external partial condensation and to separate off unwanted constituents of the mixture, bleaching the product with activated carbon and separating the bleach in known manner.

Abstract: A process for the separation of ethylene glycol from glycolated water obtained from the bottom of an ethylene oxide desorption column in a process for the manufacture of ethylene oxide by catalytic oxidation of ethylene by oxygen in the vapor phase, comprising feeding said glycolated water directly from the bottom of said ethylene oxide desorption column into the top of a separation column having therebelow up to 12 theoretical plates and adding sufficient indirect heat to said glycolated water to form two streams; a first gaseous stream consisting essentially of steam which is removed from the top of said separation column and introduced into said ethylene oxide desorption column to serve therein as the desorption fluid, and a second aqueous stream containing from about 40% to 90% by weight of ethylene glycol which is removed from the bottom of said separation column.

Abstract: A water purification process is described for the removal of ammonia and optionally one or more acid gases from wastewaters such as coke-plant or coal conversion wastewaters. The process involves adding alkali to these wastewaters in amounts sufficient to react with fixed ammonia salts present in the wastewater and to enable substantial amounts of the ammonia to be evolved upon distillation, and subjecting the thus treated wastewater to distillation to remove substantial amounts of the ammonia and acid gases present from the wastewater. This process is achieved by two separate and successive distillations. In this process, the vapor streams being withdrawn from the first and/or second distillations are subjected to an impurity removal process to thereby produce a vapor stream substantially reduced in impurities, and useful as a stripping vapor in this process, and then reusing this vapor stream as a stripping vapor in the process.

Abstract: This invention relates to the use of a salt and/or a mild caustic in solution to increase the relative volatility of aromatics contained in an aqueous stream. The increased relative volatility so achieved enables more efficient concentration of the aromas via distillation. The pH of the aroma-containing aqueous stream does not exceed 7.0 through the addition of the salt or caustic to prevent aroma degradation.

Abstract: Distillation of the heavy waste stream from the manufacture of phenol via the cumene process provides an overhead stream containing phenol, acetophenone and 2-phenyl propionaldehyde. Extraction of the overhead stream with aqueous caustic removes the phenol and subsequent distillation of the remaining two components in the presence of a catalytic amount of caustic provides a substantially pure acetophenone distillate.

Abstract: Disclosed is a process for recovering a virtually water-free amine from an amine acid salt thereof. The process comprises a unique combination of phase separation stages practiced under mild heating and distillation stages. An amine product containing less than 0.2% water can be achieved by the present process. The feedstock for the process suitably is an acid scrub liquor used to scrub amine from a vapor stream thereof which has been used in a cold-box molding process in the foundry industry or in the cure of vapor permeation curable coatings in the coatings industry.

Abstract: A method is provided for removing polychlorinated biphenyl compounds (PCB) from oil contaminated therewith comprising the steps of extracting said oil with organic solvent, separating the extract, and distilling the solvent from said extract in the presence of a base.

Abstract: Disclosed is a process for recovering a virtually water-free amine from an amine acid salt thereof. The process comprises a unique combination of phase separation stages practiced under mild heating and distillation stages. An amine product containing less than 0.2% water can be achieved by the present process. The feedstock for the process suitably is an acid scrub liquor used to scrub amine from a vapor stream thereof which has been used in a cold-box molding process in the foundry industry or in the cure of vapor permeation curable coatings in the coatings industry.

Abstract: The level of aldehyde and ketone impurities in tetrahydrofuran can be significantly reduced by bringing the tetrahydrofuran into contact with sodium borohydride and then separating the modified impurities and the tetrahydrofuran.

Abstract: This invention relates to a 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 or synthetic ethanol eventhough the latter has diethyl ether as impurity. The inventive concept lies in the design and specification of the columns and the specific high pressure and low reflux ratio distillation conditions which enable each of the impurities in ethanol to be reduced below ppm. Ethanol of such purity is most desirable when used for potable or pharmaceutical purposes.

Abstract: Crude isophorone is refined by contacting it with aqueous caustic followed by washing and fractional distillation.

Abstract: A process of recovering organic solvent from a liquid waste product which waste product is heat convertible by the steps of:(a) dispersing the liquid waste product in particulate form in water, in the presence of a bentonite or hectorite clay;(b) heating the dispersion to boiling point to strip off steam and organic solvent vapor;(c) condensing the evolved steam and orgnic vapor and separating the water therefrom; and(d) recovering the residue as an aqueous free-flowing slurry of solid granule particles.

Abstract: Crude acetonitrile containing impurities such as hydrogen cyanide, allyl alcohol, oxazole and water is purified by a process including the steps of removing water lower part acetonitrile is treated with an alkali in an amount sufficient to extract water present in the crude acetonitrile, to be thereby divided into an organic liquid phase and an aqueous liquid phase, and the aqueous liquid phase is removed.

Abstract: A method for the separation of indole by distilling an indole-containing reaction fluid obtained by the reaction of aniline with ethylene glycol or by the reaction of N-(.beta.-hydroxyethyl)aniline, which comprises bringing the reaction fluid into contact with a basic substance prior to and/or during the distillation. This method can prevent the deterioration of indole during the distillation procedure.

Abstract: Halogenated hydrocarbon and uncontaminated water is recovered from a stream of process water contaminated with halogenated hydrocarbon and hydrogen halide. The process water is neutralized and then distilled to obtain a first fraction containing halogenated hydrocarbon and water and a second fraction containing uncontaminated water. The first fraction is allowed to settle into layers of halogenated hydrocarbon and water which are then removed.The contaminated stream may be obtained from a process for the solvent dewaxing of a petroleum fraction.

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: In the refining of crude acidic tetrahydrofuran prepared from acetylene and formaldehyde, corrosion of refining equipment and formation of color-producing methacrolein can be minimized by bringing the pH value of the crude tetrahydrofuran to within the range 5-11 before the refining step.