Nitto Kagaku Kogyo Kabushiki Kaisha

Nitto Kagaku Kogyu Kabushiki Kaisha

Yoshiro Ashina

Takeyuki Fujita

Michio Fukatsu

Junsuke Yagi

Takeshi Inagaki

Kiyonobu Niwa

Yuko Nikaido

There is provided a method for maintaining the activity of a zeolite catalyst in the catalytic production of methylamines from methanol and ammonia using a zeolite catalyst as at least one of catalysts applied, which comprises controlling the amount of aldehyde compounds as impurities flowing into a zeolite catalyst layer to about 0.15 g/hr.kg-cat. or lower, as calculated in terms of formaldehyde.

Method for maintaining the activity of zeolite catalysts

A process for the selective production of dimethylamine in preference to mono- and trimethylamines by a catalytic vapor phase reaction of ammonia and methanol over a zeolite selected from mordenite, clinoptilolite and erionite is disclosed, wherein the improvement is characterized by the fact that the zeolite used has been contacted with steam at a temperature of 250.degree. to 700.degree. C.

Process for producing dimethylamine in preference to mono- and

Catalytic production of dimethylamine in preference to mono- and trimethylamine over a mordenite catalyst is disclosed, which mordenite is characterized by its alkali metal content.

Process for producing dimethylamine in preference to mono- or

Methylamines rich in dimethylamine are produced through two-step reaction of ammonia and methanol in which two types of catalysts are used and the methylamine mixture produced is recycled to the first step reaction.

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Zushi, Japan

Yoshiro Ashina