Nippon Shokubai Co., Ltd.

Akimasa Watanabe

Takahiro Takinami

Akiko Yamauchi

Noriji Morikawa

Tomoki Miyatake

Shunsuke Iwakura

The present invention is to provide a means that can reduce coloring of secondary alcohol alkoxylate. The present invention relates to a method for producing a secondary alcohol alkoxylate which comprises feeding an alkylene oxide from a plurality of positions in a tubular reactor to a secondary alcohol to react them, wherein the alkylene oxide is fed in such a manner that a feeding interval is extended and a feeding rate is increased each with a specific proportion.

Method for producing secondary alcohol alkoxylate

[Objective] An object is to provide a method for producing a diol by which diols having a favorable color scale and containing a reduced amount of an unsaturated aliphatic hydrocarbon can be produced. [Solution] A method for producing a diol, including a) supplying metaboric acid, a saturated aliphatic hydrocarbon and a reaction gas containing molecular oxygen to a reactor and performing liquid-phase oxidation of the saturated aliphatic hydrocarbon with the reaction gas containing molecular oxygen in the presence of metaboric acid to obtain a reaction liquid containing an oxide, b) esterifying the oxide to obtain a reaction liquid containing a borate compound, c) separating the reaction liquid containing a borate compound into an unreacted saturated aliphatic hydrocarbon and a distillation residue by distillation, d) separating the distillation residue into orthoboric acid and an organic layer by hydrolysis, e) separating the organic layer into an alkali aqueous solution layer and a crude alcohol layer by saponification with an alkali, and f) performing first distillation on the crude alcohol layer to remove a monoalcohol, and then performing second distillation on the residual liquid under conditions of a temperature of lower than 250&#xb0; C. and a residence time of shorter than 60 minutes.

Method for producing diol

[Problem] To provide a novel technology by which energy efficiency can be further improved in a process for producing ethylene oxide. [Solution] A method for producing ethylene oxide including: an ethylene oxidation reaction step in which ethylene is subjected to catalytic vapor-phase oxidation using a molecular oxygen-containing gas in the presence of a silver catalyst; supplying an ethylene oxide-containing reaction product gas produced in the ethylene oxidation reaction step to an ethylene oxide absorption column; bringing the reaction product gas into contact with an absorption liquid supplied to the ethylene oxide absorption column; supplying an ethylene oxide-containing column bottom liquid of the ethylene oxide absorption column to an ethylene oxide purification system; purifying ethylene oxide in the ethylene oxide purification system; supplying at least a part of a carbon dioxide gas-containing gas discharged from a column top part of the ethylene oxide absorption column to a carbon dioxide gas absorption column; extracting a carbon dioxide gas-rich absorption liquid obtained by contact of the carbon dioxide gas-containing gas with an absorption liquid as a column bottom liquid of the carbon dioxide gas absorption column; supplying the carbon dioxide gas-rich absorption liquid to an upper part of the carbon dioxide gas stripper column; stripping the carbon dioxide gas from the carbon dioxide gas-rich absorption liquid; and discharging the carbon dioxide gas from a column top part of the carbon dioxide gas stripper column as an exhaust gas, the ethylene oxide purification system including an ethylene oxide purification column provided with a reboiler in a lower part thereof, and a heating medium for heating the reboiler being heated by heat exchange with the exhaust gas.

Growing community of inventors

Kanagawa, Japan

Akimasa Watanabe