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Morphological analysis of zeolites with low si/al ratio prepared from venezuelan clays

Abstract:

From two Venezuelan clays, low Si/Al zeolites were synthesized with suitable properties for steam adsorption and possible application in the dehydration of natural gas. The starting clay was calcined at 850 ˚C for 4 h, to be used as a silicon and aluminum source, with added in some cases of aluminum or silicon source additional, and performing the synthesis by hydrothermal treatment at 100 °C for 24 h. The solids obtained were identified by X-Ray Diffraction (XRD), scanning electron microscopy (SEM), and adsorption capacity of water vapor was determined. The nature of the starting material was different in the two clays used; clay type A from the west of the country was mainly pyrophyllite, while clay type B from Bolivar State contained a high kaolinite proportion. With the first material was possible to obtain Sodalite structure (SOD) as single crystalline phase, as well as mixtures of zeolite A-SOD, or faujasite (FAU) and NaP zeolites (FAU) with SOD. With the B type clay, it was possible to obtain zeolites type A, FAU and NaP1 contaminated with quartz present in the starting clay. In attempts FAU synthesis aging period at room temperature for 24 h, favors the formation of the zeolitic phase, improving the water adsorption capacity of the final solid.