Mitsubishi Chemical Corporation

Kazuyuki Okubo

Hiroshi Iwasaka

Kazuhiro Makino

Koji Hata

Masanori Yamamoto

Toshiyuki Hamano

Yoshio Akahane

A problem of the invention is to provide a process of producing polyesters having a stable quality and a process of producing polyesters with a greatly reduced load against the environment. The invention relates to a process of producing polyesters by using a polycondensation reaction apparatus provided with one or more sets of an ejector, a condenser placed in the downstream portion of the ejector and a hot well tank connected to the condenser via a barometric leg and including a step of driving the ejector by a vapor composed mainly of 1,4-butanediol, condensing the vapor composed mainly of 1,4-butanediol as discharged from the ejector in the condenser placed in the downstream portion of the ejector, and making the reactor in a reduced pressure state to undergo polycondensation reaction, characterized in that the concentration of tetrahydrofuran contained in a sealing liquid in at least one hot well tank is not more than 4% by weight.

Process of producing polyesters

A method of contact catalytic reaction by introducing a gas and a liquid into a lower part of a reaction zone comprising a liquid phase and a catalyst-packed bed held therein, where the catalyst-packed bed is a fixed bed.

Method of contact catalytic reaction

In yielding diacetoxybutene by feeding butadiene, acetic acid, and oxygen in the presence of a solid catalyst containing palladium, the butadiene can be efficiently reacted to produce diacetoxybutene in high yield by feeding an oxygen-containing gas containing 7 mol % or more oxygen as fine bubbles to a reaction zone containing the solid catalyst.

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Mie, Japan

Kazuyuki Okubo