Ube Industries, Inc.

Yukio Inaba

Takafumi Hirakawa

Yohsuke Ueno

Hiroshi Kofuji

Kazunori Fujita

Tomohiko Yamamoto

Joji Funatsu

Genji Koga

Hideki Noguchi

Suzuo Takiguchi

Susumu Tahara

Masahiko Watanabe

Takashi Miyatake

Yasuhiro Kurokawa

Takayuki Tsujino

Tohru Murakami

Hiromi Yabuta

Taisei Igarashi

Hiroyuki Iida

Kanji Oyama

Yukihiro Nishida

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

Oxamide is produced in a high purity by a process comprising (A) melting a starting material comprising 70 to 100 wt % of an oxalic acid diester of an aliphatic alcohol and 0 to 30 wt % of the same aliphatic alcohol as mentioned above, (B) feed-mixing an ammonia-containing gas to the starting material melt, while stirring, to produce oxamide and the aliphatic alcohol (by-product), (C) continuing the ammonia-feed-mixing procedure while controlling a feed rate of ammonia to an extent such that a content of the aliphatic alcohol in the reaction mixture is maintained at a level of 3 to 45% by weight, to produce a wetted solid reaction product comprising the resultant oxamide and the aliphatic alcohol, and then (D) collecting the oxamide from the reaction product by evaporating away the aliphatic alcohol.

Process for producing oxamide

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.

Process and apparatus for producing dihydric phenolic compound

A process for preparing a high purity H.sub.2 O.sub.2 aqueous solution, which comprises the steps of: (a) feeding a crude H.sub.2 O.sub.2 aqueous solution containing H.sub.2 O.sub.2, organic carbon impurities and inorganic impurities into a distillation column having an inner wall at least the surface of which is made of a fluorine resin and internals and packings at least the surface of which are made of a fluorine resin being provided internally of the distillation column, from a bottom portion of the distillation column; (b) subjecting the crude hydrogen peroxide aqueous solution to distillation under reduced pressure and under heating the bottom portion; (c) taking out a distillate containing an extremely low concentration of H.sub.2 O.sub.2 from a top portion of the distillation column without using the distillate for reflux in a distillation operation, and feeding ultra pure water in an amount satisfying (an amount of ultra pure water fed into column top)/((an amount of column top distillate)--(an amount of ultra pure water fed into column top)) being 0.1 to 20 into the top portion of the distillation column; and (d) taking out a H.sub.2 O.sub.2 aqueous solution having a high purity from a middle portion of the distillation column, simultaneously or successively.

Process for preparing high purity hydrogen peroxide aqueous solution

This invention relates to a process for purifying a hydrogen peroxide aqueous solution, which comprises bringing a high concentration hydrogen peroxide aqueous solution containing a large amount of phosphoric acid obtained by extracting with water a reaction mixture prepared by a method of forming hydrogen peroxide by an oxidation-reduction process of anthraquinones, into contact with specific active alumina particles at a temperature of 0.degree. to 50.degree. C. for 6 to 500 minutes to remove a phosphoric acid component from the above high concentration hydrogen peroxide aqueous solution at a high rate substantially without causing decomposition of hydrogen peroxide.

Process for purifying hydrogen peroxide aqueous solution

Oxamide granules are produced by (A) feed-mixing ammonia to a starting material comprising 60 to 100 weight % of a diester of oxalic acid with a C.sub.1-6 aliphatic alcohol, and 0 to 40 weight % of the same aliphatic alcohol as mentioned above, to produce oxamide and the aliphatic alcohol as by-product, while controlling the aliphatic alcohol content to 5 to 40% based on the weight of the reaction mixture to provide the resultant oxamide wetted by the aliphatic alcohol; (B) granulating the wetted product while maintaining the content of the aliphatic alcohol at a level of 5 to 40% based on the weight of the wetted reaction product; (C) heat-evaporating away the aliphatic alcohol from the wetted granules; and optionally (D) re-wetting the resultant dry oxamide granules with water in an amount of 5 to 20% based on the weight of the dry oxamide granules; and (E) re-drying the re-wetted oxamide granules, to provide oxamide granules having an enhanced mechanical strength and form-stability in water.

Process for producing oxamide granules

Disclosed is a process for preparing .epsilon.-caprolactone comprising using a percarboxylic acid solution obtained by oxidizing organic carboxylic acid in an organic solvent in the presence of hydrogen peroxide and a boric acid catalyst, and cyclohexanone, supplying 1 to 1.5 mole of percarboxylic acid, 0.012 mole or less of hydrogen peroxide and 0.04 mole or less of the boric acid catalyst per mole of cyclohexanone in a reaction system, and reacting said cyclohexanone with said percarboxylic acid to form .epsilon.-caprolactone.

Process for preparing .epsilon.-caprolactone

Disclosed is an ion exchange purification method of an aqueous caprolactam solution in a process for producing caprolactam and laurolactam by subjecting a mixture of cyclohexanone oxime and cyclododecanone oxime to Beckmann rearrangement in the presence of sulfuric acid and fuming sulfuric acid, which comprises, after neutralization of the rearrangement reaction products, and first extraction thereof with an organic solvent and second extraction of the first extract with water to obtain a second extract of an aqueous caprolactam solution, treating the aqueous caprolactam solution obtained by extraction with an organic solvent immiscible with water with a strongly acidic cation exchange resin, and subsequently with a weakly basic anion exchange resin or further with a strongly basic anion exchange resin.

Ion exchange purification method of aqueous caprolactam solution

A process for preparing perpropionic acid solution comprising reacting propionic acid with hydrogen peroxide in the presence of a boric acid catalyst wherein the reaction is carried out by using an ethyl propionate as a reaction solvent, and water in the reaction solution is removed continuously by azeotropic distillation with the reaction solvent. Since the reaction is carried out while the concentration of the peroxide in an aqueous phase separated from the distillate by the azeotropic distillation is maintained at not more than 0.1% by weight, a perpropionic acid solution containing almost no unreacted hydrogen peroxide can be prepared.

Process for preparing perpropionic acid solution

Disclosed is a process for stabilizing a percarboxylic acid characterized in that the percarboxylic acid is mixed with at least one pyridine derivative selected from the group consisting of picoline, ethylpyridine, conyrine, lutidine and N-oxide thereof.

Process for stabilizing percarboxylic acid

A process for the preparation of a 2,3-dihydro-2-methyl-2,3-dialkyl-7-oxybenzofuran having the formula (I): ##STR1## in which R and R' are the same or different and each represents a lower alkyl group or hydrogen atom, which comprises reacting catechol with an aldehyde having the formula (II):

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Ube, Japan

Yukio Inaba