Mitsui Toatsu Chemicals, Incorporated

Mitsui Chemicals, Inc.

Kunihiro Yamada

Shinji Takenaka

Yukihiro Yoshikawa

Teruo Hirayama

Jyoji Morisaki

Tooru Hihara

Hisato Itoh

Hideki Mizuta

Katsuharu Miyata

Yasuhiro Takano

Kazunori Kawahara

Jun Kitagawa

Kaoru Sakadera

Hironori Kamachi

A preparation process of N,N&prime;-dialkylalkanediamine by reacting dihaloalkane with lower alkylamine characterized by carrying out the reaction with controlling the residual amount in the reaction system of haloalkaneamine intermediate represented by the formula (4):

Process for the preparation of N,N&prime;-dialkylalkanediamines

A method for preparing an improved catalyst for use in the preparation of chlorine by the oxidization of hydrogen chloride with an oxygen-containing gas. The catalyst mainly comprises chromium oxide and can be used for a long period of time particularly under low oxygen content conditions, and the activity of the catalyst does not easily deteriorate, and in other words, the catalyst has a long life. Furthermore, there are disclosed the catalyst obtained by this preparation method, and a method for preparing chlorine from hydrogen chloride by the use of the catalyst. The method for preparing the improved catalyst comprises adding copper, an alkali metal and a rare earth metal, or adding chromium, copper, an alkali metal and a rare earth metal to a catalyst containing chromium oxide as a main component, and then calcining the catalyst at a temperature of 800.degree. C. or less.

Catalyst for preparing chlorine from hydrogen chloride

Disclosed herein is a method for the stabilizing treatment of a catalyst comprising washing the catalyst with hot washing water following the preparation of the catalyst, the catalyst being composed principally of chromium oxide and used in the production of chlorine by the oxidation of hydrogen chloride with an oxygen-containing gas, thereby improving its catalytic activity and prolonging its life.

Method for stabilizing treatment of catalytic activity

The catalytic activity of a chromium oxide-based catalyst used in the production of chlorine by oxidation of hydrogen chloride gas with an oxygen-containing gas is regenerated by impregnating it with an aqueous solution of chromic acid anhydride or of a chromium salt and then calcining the catalyst at a temperature not higher than 800.degree. C.

Chromium oxide catalyst impregnation regeneration method

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Fukuoka, Japan

Kunihiro Yamada