Process for preparing bound zeolites
AssigneeEnichem S.p.A.
InventorsAngela Carati, Giuseppe Bellussi, Maria Angela Mantegazza, Giudo Petrini
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Abstract
A process is described for the preparation of zeolitic catalysts in the form of microspheres, comprising zeolite and oligomeric silica, characterized by a high mechanical resistance. The process consists in subjecting to rapid drying the suspension, to which tetra-alkylorthosilicate is optionally added, resulting from the synthesis of zeolite by hydrothermal treatment at autogenous pressure of the reagent mixture containing tetra-alkylammoniumhydroxide as templating agent, and subjecting the product resulting from the drying to calcination.
Claims3
A process for preparing MFI zeolites having the formula p HMO2·q TiO2·SiO2, wherein M is a metal selected from the group consisting of aluminum, gallium and iron, p has a value ranging from 0 to 0.04 and q has a value ranging from 0.0005 to 0.03, which comprises:
- subjecting to hydrothermal treatment at autogenous pressure, at a temperature ranging from 190 to 230° C. and for a time ranging from 0.5 to 10 hours, without alkali metals, a mixture containing a silicon source, a titanium source, optionally a source of a metal M, and tetrapropylammoniumhydroxide as templating agent, having the following composition expressed as molar ratios:
- Si/Ti=35-2000
- M/Si=0-0.04 wherein M is selected from Al, Ga and Fe
- TPA-OH/Si=0.2-0.5 wherein TPA=tetrapropylammonium
- H2O/Si=10-35.
A process for preparing MFI/MEL or MEL zeolites having the formula x TiO2·(1−x) SiO2 wherein x has a value ranging from 0.0005 to 0.03, which comprises:
- subjecting to hydrothermal treatment at autogenous pressure, at a temperature ranging from 190 to 230° C. and for a time ranging from 0.5 to 10 hours, without alkali metals, a mixture containing a silicon source, a titanium source, tetra-alkylammoniumhydroxide as templating agent, having the following composition expressed as molar ratios:
- Si/Ti=35-2000
- TAA-OH/Si=0.2-0.5
- H2O/Si=10-35.
Dependencies are inferred from the claim text.