Abstract: Tert.butyl alkyl ethers are produced from a C.sub.4 hydrocarbon feedstock containing isobutene, and the butene-1 is recovered at high purity by extractive distillation of the isobutene-free C.sub.4 hydrocarbon stream in the presence of a solvent chosen from acetone, acetonitrile, dimethylformamide, methanol, n-methylpyrrolidone, formylmorpholine and furfural.After removing the solvent, the extract is rectified, and the butene-1 separates as overhead product of high purity.

Abstract: In the production of high purity phenol, a water-phenol mixture recovered from the top of a distillation column is contacted with a water immiscible solvent to extract methyl benzofuran and other by-products and impurities in phenol production therefrom, with the extraction being accomplished at a temperature at which the water-phenol mixture is present as a single phase liquid. The remaining mixture of phenol and water is recycled to the distillation.

Abstract: MTBE is recovered from an ether containing effluent by fractionation. When driers are not used on the hydrocarbon feed to MTBE manufacture, a separate water-methanol phase occurs in the fractionation overhead which is separately processed in a methanol fractionator and the water recovered is used to water wash the separated hydrocarbon phase from the overhead while methanol is recycled to MTBE and when driers are used on the hydrocarbon feed a separate methanol phase occurs in the fractionation overhead which can be recycled to MTBE manufacture and the hydrocarbon phase is directly passed to a drier preceding alkylation.

Abstract: A process for producing gasoline-ethanol blends comprises purifying dilute ethanol by extractive distillation and concentrating the ethanol by distillation followed by one or both of the following steps: (a) liquid extraction of ethanol into heated gasoline or (b) azeotropic distillation of ethanol with an entrainer followed by blending with gasoline.

Abstract: Methylnaphthalenes, indole and other tar bases are recovered from a base-extracted coal tar distillation fraction. In one form, an aqueous salt solution of pH 0.5-3 extracts other tar bases from the starting material, and thereafter both products are recovered from the raffinate by several alternate methods including ethylene glycol extraction and extractive distillation. In other forms, the starting material is extracted with ethylene glycol and the extract is distilled to recover several products including indole. The raffinate of ethylene glycol extraction contains methylnaphthalenes and other hydrocarbons and can be purified to solvent-grade material.

Abstract: In a process for separating trioxane by a continuous distillation which comprises extracting, with benzene, the trioxane-containing distillate obtainable by heating an aqueous solution of formaldehyde, feeding the trioxane-containing benzene solution into a distillation column as a starting material, distilling out the benzene from the column top and withdrawing the trioxane from the column bottom, a process for separating trioxane which comprises retaining the concentration of trioxane X in the liquid composition at the starting material feeding plate of the distillation column (% by weight of trioxane based on the total liquid composition at the feeding plate) in the range satisfying the following relationship: ##EQU1## wherein R is reflux ratio, and .gamma. is a parameter defined by the following equation: ##EQU2## wherein q is the proportion of liquid part in the fed starting material as expressed in terms of ratio by weight and C (%) is the concentration of trioxane in the fed starting material.

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: There is disclosed an azeotropic distillation process for separating and recovering hexamethyl disiloxane (HMDO) from toluene in a spent liquor mixture. An HMDO azeotrope former, pyrrolidone, is added to the liquor. The pyrrolidine is added in an amount of at least about 1.81 parts by weight per 1.0 part by weight of HMDO. Preferably, it is added in excess, as about 2.7 to about 5.4 parts by weight of pyrrolidine per 1.0 part by weight of HMDO. The resulting azeotrope of HMDO and pyrrolidine is then separated by distillation from the liquor. The pyrrolidine may be subsequently recovered from the HMDO by extraction with water. Other HMDO azeotrope formers, such as tertiary butanol, may also be utilized.

Abstract: Methyl tertiary butyl ether may be recovered from etherification reaction effluent by azeotropic distillation to recover methanol-ether azeotrope overhead which is water-washed to give pure ether raffinate plus ether-methanol bottoms, the latter being azeotropically distilled to yield ether-methanol overhead which is recycled to water-washing.

Abstract: A process for the recovery of materials suitable for recycle to the manufacture of alkoxy or aryloxyphosphazenes including, inter alia, solvents, hydroxy compounds, acid acceptors and the like, from flash distillation of the washed phosphazene product together with a second vapor stream produced from the aqueous wash of the crude phosphazene product, whereby an aqueous phase and an organic phase are produced and recyclable materials are extracted from the aqueous phase into the organic phase, separating the organic phase from the aqueous phase and separating the organic phase into components by conventional methods which are suitable recycle streams for the phosphazene product manufacturing process.

Abstract: A method for separating and recovering hydroquinone which comprises distilling a by-product-containing acid-cleavage product, which is obtained by acid-cleavage of an oxidation product of para-diisopropyl benzene in a solvent, in the presence of an aromatic hydrocarbon, thereby removing low-boiling fractions including the solvent, bringing the resulting hydroquinone-containing distillation bottoms into contact with water, and crystallizing and separating hydroquinone; characterized in thatA. the distilling off of the low-boiling fractions is effected without the addition of water and in the absence of an azeotropic amount of water and also in the presence of an aromatic hydrocarbon containing 9 to 10 carbon atoms, andB. the contacting of the distillation bottoms with water is effected under conditions which do not induce crystallization of hydroquinone in the distillation bottoms.

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: A hydrocarbon mixture consisting of an aromatic and a non-aromatic component is subjected to a liquid-liquid extraction and/or an extractive distillation. A solvent is used which selectively dissolves the aromatic component so as to form an extract phase. The extract phase is introduced into a distillation column for separating the solvent and the aromatic component. The column is provided with trays and the extract phase is introduced into the column at about the middle thereof from where the solvent flows downwardly and the aromatic component flows upwardly. Sufficient water is introduced into the sump of the column to insure that the trays above the location at which the extract phase enters the column are filled with water during the separation. This improves the operation of the distillation column. An arrangement for carrying out the above process is also disclosed.

Abstract: Methyl tertiary butyl ether may be recovered from etherification reaction effluent by azeotropic distillation to recover methanol-ether azeotrope overhead which latter is azeotropically distilled in the presence of n-pentane to give pure ether bottoms substantially free of water and methanol.