Mitsui Petrochemical Industries, Ltd.

Kazuhiro Watari

Hirohiko Nambu

Kenichi Mizuno

Tadateru Murakami

Seiichi Tanaka

Norio Ohno

Mitsutoshi Moriyama

Katsuhiko Hashimoto

Hideki Hayashi

Yutaka Matsuoka

Disclosed is a process for the preparation of phenols which comprises reacting an .alpha.-hydroxyalkyl-substituted aromatic compound and/or an .alpha.,.beta.-unsaturated alkyl-substituted aromatic compound with hydrogen peroxide in the presence of an acid catalyst, in which hydrogen peroxide is diluted with a diluent, especially acetone, so that the volume is at least 10 times the original volume, and the diluted hydrogen peroxide is supplied in a divided manner to at least two portions of a reaction vessel or the diluted hydrogen peroxide is scattered by sprinkling into the reaction vessel. According to a preferred embodiment, the diluted hydrogen peroxide is continuously supplied to the gas phase in the reaction vessel from a scattering device which is similar to but separate from a scattering device for supplying the starting aromatic compound, particularly, a product formed by oxidizing an isopropyl aromatic compound with molecular oxygen. According to this process, the efficiency of utilization of hydrogen peroxide is increased and a phenol of high quality can be obtained in a high yield with a high safety.

Process and apparatus for preparation of phenols

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 that A. 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, and B. the contacting of the distillation bottoms with water is effected under conditions which do not induce crystallization of hydroquinone in the distillation bottoms.

Method for separation and recovering hydroquinone

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Ohtake, Japan

Kazuhiro Watari