Nippon Shokubai Co., Ltd.

Yoshinari Yamaguchi

Hitoshi Yano

Yuuji Shimasaki

Ryuichi Ishikawa

Yukihiro Matsumoto

Michio Ueshima

Kimio Ariyoshi

Akira Kurusu

Teruhisa Kaziwara

Hirokazu Ito

A process for recovering N-vinyl-2-pyrrolidone is provided which allows to recover N-vinyl-2-pyrrolidone efficiently and steadily and in high purity by continuous distillation from a mixed liquid containing N-vinyl-2-pyrrolidone, N-(2-hydroxyethyl)-2-pyrrolidone, compounds having a higher boiling point than N-vinyl-2-pyrrolidone and water. The process includes continuously distilling the mixed liquid using a distilling column, controlling the temperature of the bottom liquid of the distilling column at 180&deg; C. or less.

Process for recovering N-vinyl-2-pyrrolidone

Method of recovering and dehydrating ethylene sulfide

In a process for preparing alkylene sulfides through the intramolecular dehydration reaction of mercaptoalkanols in a gaseous phase, catalysts are used, which are represented by the formula: M.sub.a X.sub.b Y.sub.c O.sub.d, where M represents at least one element selected from the group of alkali metals, alkaline earth metals and thallium; X represents at least one element selected from the group of Al, B, Si and P; Y represents at least one element selected from the group consisting of lanthanides, IIIA group, IVA group, VA group, IIIB group, IVB group, VB group and VIB group, excluding an element contained in M or X; O represents oxygen; and a and b are numerical values not equal to 0; b=0.2-100 and c=0-50 when a=1; and d is a numerical value determined according to a, b and c.

Process for preparing alkylene sulfides

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Suita, Japan

Yoshinari Yamaguchi