Ube Industries, Inc.

Hiroshi Kofuji

Yukio Inaba

Kazunori Fujita

Shuji Tanaka

Genji Koga

Tetsuro Kawashita

A refined dihydroxyaryl compound, for example, catechol, having a high degree of purity and a very low metal content is produced by evaporating a starting dihydroxyaryl compound in a distillation column, condensing the vapor fraction in a condenser connected to a top outlet of the distillation column, and collecting the condensed fraction from the condenser into a storage tank through a conduit, wherein the condenser and optionally the conduit and/or the storage tank have inside surfaces thereof formed from a metal material containing at least 25% by weight of nickel, and the condensed dihydroxyaryl compound fraction is brought into contact with the specific nickel (25% or more)-containing metal inside surface.

Method of refining dihydroxyaryl compound

A mixed liquid of two or more components different in boiling temperature from each other and soluble in or compatible with each other is evaporated into a mixed vapor having a similar composition to that of the mixed liquid by using an apparatus having a thin film evaporator ( ) having a feed inlet (1 ) and a delivery outlet (1 ), while forcedly circulating the non-evaporated portion of the mixed multi-component liquid by withdrawing the non-evaporated mixed liquid portion from the delivery side end portion of the evaporator and returning the mixed liquid portion into the feed side end portion of the evaporator through a circulating line ( ), and the resultant mixed multi-component vapor can be used as a mixed material vapor for a gas phase catalytic reaction for producing, for example, a mono and/or a di-alkylether of an aromatic dihydroxy compound.

Apparatus and process for generating mixed multi-component vapor

A heat-deteriorative compound contained in a liquid mixture is refined by a distillation procedure using a distillation column in which a vapor fraction and a liquid fraction containing the heat-deteriorative compound are generated from the liquid mixture, and a liquid film-falling reboiler in which the liquid fraction falls in the form of liquid films along inner surfaces of a plurality of vertical heat-conductive pipes at a Reynolds number (Re) of 700 to 10,000 and heated to a temperature lower than the heat-deterioration temperature of the heat deteriorative compound to such an extent that 1 to 15% by weight of the liquid fraction is evaporated per pass through the reboiler, the heated liquid fraction being returned into the distillation column to generate the vapor fraction from the liquid mixture fed into the distillation column.

Process for refining heat-deteriorative compound, contained in multi-component liquid mixture, by distillation

A dihydric phenolic compound is produced, with a high selectivity thereof, by a plurality of oxidation reactors connected to each other in series, by (1) feeding a monohydric phenolic compound with a temperature of 30 to 100&deg; C., a peroxide compound, a catalyst and optionally a ketone compound into a first reactor to oxidize the monohydric phenolic compound, and delivering a resultant reaction mixture containing the produced dihydric phenolic compound and non-reacted monohydric phenolic compound from the first reactor; (2) passing the reaction mixture through one or more reactors succeeding to the first reactor, to further oxidize the monohydric phenolic compound, while, in the steps (1) and (2), a portion of the peroxide compound is fed into the first reactor and the remaining portion of the peroxide compound is fed into at least one succeeding reactor; and (3) delivering a first reaction mixture produced in a rearend reactor and comprising the produced dihydric phenolic compound, the non-reacted monohydric phenolic compound and peroxide compound and the catalyst from the rearend reactor.

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Ube, Japan

Hiroshi Kofuji