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: Highly decolorized, purified hydroquinone and resorcinol can be separated from each other from a mixture containing hydroquinone and resorcinol and recovered by continuously rectifying the mixture, thereby obtaining rectification bottoms containing resorcinol and hydroquinone in a ratio by weight of resorcinol to hydroquinone of 0.1-1:1 while obtaining resorcinol as a distillate, redistilling the rectification bottoms, contacting hydroquinone vapor with water vapor, condensing the hydroquinone vapor in the presence of the water vapor, thereby recovering hydroquinone as an aqueous hydroquinone solution, and then recrystallizing the aqueous hydroquinone solution, if necessary, in the presence of an organic solvent, thereby separating hydroquinone from the aqueous solution.

Abstract: A method for extracting a dihydroperoxide of a dialkylbenzene of the formula, ##STR1## wherein each R.sub.1, R.sub.2, R.sub.3 and R.sub.4 is independently a lower alkyl group, from an aqueous alkali solution of the said dihydroperoxide with at least one organic solvent selected from the group consisting of C.sub.4 -C.sub.10 ketones, C.sub.4 -C.sub.10 ethers and C.sub.4 -C.sub.8 alcohols, which comprises extracting the dihydroperoxide by a countercurrent multi-stage extraction at a temperature between 0.degree. and 85.degree. C with a temperature gradient, the aqueous alkali solution being fed to the lower temperature zone, the organic solvent being fed to the higher temperature zone, and each aqueous alkali solution and organic solvent being fed countercurrently, whereby the dihydroperoxide is obtained in the form of organic solvent solution from the lower temperature zone.

Abstract: A process for the continuous production of .beta.-isopropylnaphthalene hydroperoxide comprising oxidizing an isopropylnaphthalene mixture containing .alpha.- and .beta.-isopropylnaphthalene isomers with molecular oxygen or a molecular oxygen containing gas in an oxidation zone and recycling unreacted ispropylnaphthalene recoverd after the oxidation to the oxidation zone, in which the oxidation is carried out by controlling the .alpha.-isopropylnaphthalene content in the isopropylnaphthalene mixture continuously fed to the oxidation zone to about 15% by weight or less.

Abstract: A process for recovery of urea from a phenolic solution thereof which comprises adding an organic solvent selected from the group consisting of aliphatic amides, ethers, carbon disulfide and dimethylsulfoxide to the said phenolic solution and collecting the separated crystals of urea from the resultant mixture. The process is characteristic in recovering urea in the solid state without the use of water but a particular organic solvent.

Abstract: A method for separating m- or p-cresol from a mixture of m- and p-cresols having a composition outside the two compositions which give respectively the eutectic points, characterized by subjecting the mixture to a crystallization treatment under a pressure of not less than about 300atmospheres.

Abstract: A process for purifying crude .beta.-naphthol obtained via an alkylnaphthalene hydroperoxide, comprising subjecting the crude .beta.-naphthol to a recrystallization treatment using (1) an aliphatic or alicyclic hydrocarbon solvent having 5 to 10 carbon atoms, or (2) a mixed solvent comprising the aliphatic or alicyclic hydrocarbon solvent and at least one other solvent selected from the group consisting of benzene, a benzene derivative, a ketone, an alcohol, an ether and an ester.

Abstract: Resorcinol and hydroquinone are recovered in mixture at a high purity from a solution containing resorcinol and hydroquinone, especially, a solution resulting from cleavage of oxidation products of isopropylbenzene and successive distillation of the cleavage product thereby to remove lower and higher boiling components therefrom, by adding 0.

Abstract: Meta-and/or paradiisopropylbenzene dihydroperoxides are continuously produced by oxidizing meta-and/or paradiisopropylbenzenes in liquid phase through contact with oxygen or a gas containing oxygen, while keeping the concentration of meta-and/or paradiisopropylbenzene monohydroperoxides of the oxidation product solution in a range of 20 to 40% by weight.

Abstract: Impurities, that is, by-products, in an oxidation product solution obtained by oxidation of diisopropylbenzene by molecular oxygen or in the oxidation product solution freed from diisopropylbenzene dihydroperoxide, are removed by extracting the by-products such as carbinols, ketones and styrenes from the solution with a mixture of an aqueous alkaline solution and at least one of alcohols having 1 to 3 carbon atoms such as methanol, ethanol, and isopropanol, as an extracting reagent at a temperature of 20.degree. to 80.degree.C.

Abstract: In a process for the production of hydroperoxides by the oxidation of an aromatic hydrocarbon having at least one tertiary carbon atom with oxygen or an oxygen containing gas in the presence of an aqueous alkaline solution, an improvement is made in that the oxidation is effected in an emulsion phase which is caused by powerfully mixing all or a part of the materials to be brought into the oxidation reaction only by the aid of the hydroperoxides formed in the reaction, whereby enhancing the reaction rate with safety.

Abstract: Dihydroperoxides of dialkylaromatic hydrocarbons are separated in high yield from an aqueous alkaline solutions of hydroperoxides containing the dihydroperoxides by adding 0.01 to 1 % by weight of a compound having a nitrogen base, such as ammonia and aromatic amines, to the solution, based on the weight of the solution, thereby stabilizing the dihydroperoxides in the solution, and separating the dihydroperoxides therefrom by extraction.