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US 5,059,567 AGranted
Process for the preparation of a modified zeolite
AssigneePQ Zeolite B. V.
InventorsOlof M. Linsten, Arne O. Frestad
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AssigneePQ Zeolite B. V.
InventorsOlof M. Linsten, Arne O. Frestad
Estimating the term…
Zeolite Y comprising aluminum ions supplied and fixed by ion-exchange is produced by subjecting zeolite NaY to a series of treatment steps comprising e.g. ammonium ion-exchange and calcination. In order to supply and fix the aluminum ions, an aluminum ion-exchange is carried out, followed by further calcination in a saturated or substantially saturated steam (water vapor) atmosphere at 400.degree.-900.degree. C. If the zeolite unit cell size is to be reduced to 24.15-24.35 .ANG., simultaneously as the aluminum ions are fixed, the last-mentioned calcination is carried out in a saturated or essentially saturated (steam) water vapor atmosphere at 500.degree.-900.degree. C. It is further disclosed that the steam used in the calcination step can be supplied either from an external source or solely by vaporization of water present in the zeolite.
An improved process for the production of a modified zeolite Y comprising aluminum ions supplied and fixed by ion-exchange and preferably also having a small unit cell size, in which process NaY zeolite is prepared and subjected to a series of treatment steps comprising ammonium ion-exchange, calcination, aluminum (III) ion-exchange and drying, the improvement which comprises subjecting the zeolite, after the aluminum (III) ion-exchange step, to a further calcination step, at least the last-mentioned calcination step being carried out in a steam atmosphere at 400-900.degree. C. to fix the aluminum ions supplied by ion-exchange.
In a process for the production of a modified zeolite Y comprising subjecting a NaY zeolite to a series of treatment steps comprising ammonium ion-exchange, calcination, aluminum ion-exchange and drying, the improvement which comprises subjecting the zeolite, after the aluminum (III) ion-exchange step, to a further calcination step, at least the last-mentioned calcination step being carried out at 400.degree.-900.degree. C. in a steam atmosphere wherein the steam is supplied solely from vaporization of the water present in the zeolite.
Dependencies are inferred from the claim text.