Prepação de MCM-22 em sistemas estatico e agitado

AUTOR(ES)
DATA DE PUBLICAÇÃO

2000

RESUMO

Zeolite MCM-22 was first synthesized by Mobil researchers in 1990. It is an aluminosilicate with molecular sieving characteristics and several applications in catalytic processes because of its two independent pore systems. In this work we studied the synthesis conditions for this zeolite using either static or stirred hydrothermal treatment. The basicity, dilution, quantity of template and the temperature of ageing used in the reaction mixtures were varied. Zeolite MCM-22 was obtained using both systems (static and stirred) but only under very specific reactions conditions. The products obtained were characterized. It was observed that independent of the type of the hydrothermal treatment used, the characteristics of the zeolites obtained were practically the same, only the morphology of the particles was different; in a stirred system the particles were as thin dispersed platelets and in a static system the particles were like rings with the dimensions varing with the molar ratio of the reagents used in its synthesis. MCM-22 was obtained with less aluminum than that indicated in the literature. In these cases, we observed contamination of magadiite and kenyaite, members of a same family of hydrated silicates. In that way, we indicate the possibility of MCM-22 synthesis in static systems with a shorter hydrothermal treatment than that reported in the literature, and with the same quality and characteristcs of that one obtained with a dynamic hydrothermal treatment.

ASSUNTO(S)

peneiras moleculares silicato de aluminio zeolitos

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