On the crystallization of zeolites from waste FCC catalysts

MAXIMILIANO R. GONZÁLEZ; ANDREA M. PEREYRA; ELENA I. BASALDELLA

Rio de Janeiro

Conferencia; 18th International Zeolite Conference; 2016

International Zeolie Association y Brazilian Catalysis Society

Zeolites are used not only as molecular sievesand ion exchangers but also as catalysts due to the presence of acid sites intheir structure. Fluid catalytic cracking (FCC) is the most importantconversion process used in oil refineries. The components of these activecatalysts are crystalline zeolite, aluminosiliceous matrix, binder and kaolinclay as filler. The zeolite used in FCC catalysts is the Y type, whosestructure is identified as pertaining to the FAU group, analogous to naturalfaujasite. The other catalyst components (matrix, binder and filler) are silicaand alumina inorganic materials, being kaolin clay the main raw material usedfor the preparation of the catalyst. Additionally, the spent catalyst alsocontains small percentages of heavy metals that are incorporated during itsuse, but the silica and alumina percentages are ca. 100%, so thismaterial constitutes a potential source of starting materials for the synthesisof aluminosilicate zeolites. It is important to reutilize the waste catalysts as well as tosynthesize large amounts of zeolite A, which can be used not only as gasdesiccant for many industrial processes, among them in the detergent industry. Inthis work we present the synthesis of zeolite A, using Argentinean waste FCCcatalysts as reactants and commercial-grade alumina. The synthesis mechanism isfollowed through the radial distribution function (X-ray diffraction). Additionally,texture evolution is studied by water adsorption. The morphology of the productsreaction is observed by scanning electron microscopy (SEM).