Ube Industries, Inc.

Tomoyuki Itou

Hirofumi Ii

Akira Hino

Yoshiki Kawamura

Toshiyuki Matsushita

Tatsuya Naitou

Kazuki Yamamoto

Katsuyoshi Kudou

Tadaaki Kaneko

Takamasa Miyazaki

Hirofumi Li

A method manufactures diethyl carbonate by reaction distillation where transesterification and distillation are simultaneously performed in a multistage reaction distillation column provided with a catalyst introduction port and a raw material introduction port located below the catalyst introduction port, wherein: (a) the reaction is performed in a countercurrent flow format in which contact is brought about between a transesterification catalyst, dimethyl carbonate, and ethanol; (e) 1 to 250 mmol of catalyst is used per mole of dimethyl carbonate; (f) the ratio of the volume of air in the catalyst introduction port and the raw material introduction port regarding the volume of air in the reaction distillation part is 0.1 to 0.9; (g) the recirculation ratio in the reaction distillation column is 0.5 to 10; and (h) the temperature of the top part of the column and the reaction distillation part is 60 to 100&#xb0; C.

Method of manufacturing diethyl carbonate

There is provided a process for preparing 1,6-hexanediol by esterifying a carboxylic acid mixture resulted from oxidation of cyclohexane with oxygen, and then hydrogenating the esters, which substantially does not contain a compound leading to a high ester value. A process for preparing 1,6-hexanediol from a carboxylic acid mixture containing adipic acid and 6-hydroxycaproic acid, the carboxylic acid mixture is obtained as a by-product in oxidization of cyclohexane to cyclohexanone/cyclohexanol using oxygen or an oxygen-containing gas, the process comprises esterifying the acids with an alcohol, followed by hydrogenation, and the process is characterized by comprising the following steps of:

High purity 1,6-hexanediol and process for preparing the same

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Ube, Japan

Tomoyuki Itou