Sample records for faujasite

Sample records 1 - 2 shown.


Preparação e propriedades de zeólitas faujasita contendo cátions amônio/ Preparation and properties of faujasite zeolites containing ammonium cations

Almeida, Karina Arruda; Cardoso, Leandro Martins e Dilson

Resumo em inglês Sodium faujasite zeolites with Si/Al ratio of 1.4 and 2.5 were exchanged with methylammonium cations. The influence of framework aluminum and ion exchange degree in their basic properties were evaluated. These properties were assessed in the Knoevenagel catalytic condensation. The sodium ion exchange was restricted to the supercavity and the exchange degree depended on the cation volume and on the Si/Al ratio. The higher catalytic activity is achieved for the zeolite with (mais) the lower Si/Al ratio exchanged with the monomethylammonium cation. The best performance of this catalyst is attributed to the higher basicity in combination with elevated micropore volume.

Scientific Electronic Library Online (Portuguese)


Utilização de zeólitas sintetizadas a partir de xisto retortado na remoção de arsênio em águas contaminadas/ Use of zeolites synthesized from oil shale ash for arsenic removal from polluted water

Fernandes-Machado, Nádia Regina Camargo; Miotto-Bigatão, Denise Maria Malachini

Resumo em inglês The solid by-product of the oil shale processing (PETROBRAS - Brazil) was used as raw material to synthesize zeolites A and faujasite. Alkaline fusion followed by hydrothermal treatment was the synthesis procedure used, and five different starting material compositions were obtained. The more crystalline zeolite-type materials synthesized, the pretreated oil shale ash and commercial zeolites were used as adsorbents in the purification of pollutant solutions with arsenic. (mais) The zeolite-type material composed of a mixture of zeolite A (42.6%) and faujasite (52.9%) presented an ion exchange capacity comparable to the pure zeolites A and faujasite, much better than the pretreated ash.

Scientific Electronic Library Online (Portuguese)