INVESTIGATION OF MECHANICAL PROPERTIES OF ZEOLITE-Y AND ZSM-5 CATALYSTS SYNTHESIZED FROM LOCALLY AVAILABLE CLAYS

This research work was centred on mechanical properties of zeolite-Y and ZSM-5 catalysts synthesized from locally available clays such as Kaolin, Alumina, Gambe and Pindiga respectively. Pressure absorption capacities of the synthesised zeolite catalysts and that of the supportive clays were carried out with the aid of a bourdon gauge machine. Plastimeter machine alongside with a micro tensometer machine were equally used to determine the young’s modulus of the synthesized zeolite catalysts and flow characteristics of the clays. XRD analysis was carried out using Cu K α-radiation to find the textural properties. Results of the analysis indicated that synthesised ZSM-5 catalyst was denser, could absorbed more pressure as compared with synthesized Zeolite-Y catalyst. Though, in terms of flowability, synthesised Zeolite-Y is more effective than synthesise ZSM-5 catalyst. The young’s modulus of the synthesised catalysts was found to lie between 3.5 N/mm2 – 4.0 N/mm2. Among the clays analysed, alumina clay had proved a more superior support material for the synthesis of the zeolite catalysts in terms of flowability, porosity, and pore size. XRD analysis indicated that at point 2-theta (point where the highest peak occurred), the peak level of the synthesized zeolite catalysts and that of the referenced zeolite are, at the same level which indicated similarity in their performance ability.

Zeolites are micro-porous alumina-silicate minerals used for numerous commercial and domestic applications. These include applications in petroleum and petrochemical industries as catalysts, adsorbents and ion exchangers, nuclear industries for nuclear reprocessing, heating and refrigeration, detergents, construction as material additives, medicine, agriculture as a soil treatment, gemstones, as ion-exchange beds in domestic and commercial water purification and softening. The term Zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt, who observed that upon rapidly heating the material stilbite, it produced large amounts of steam from water that has been adsorbed by the material. Base on this, he called the material zeolite, from the Greekzep, meaning “to boil” And lithos meaning “stone” (Cejka et al,

2007).

Today, Zeolite-Y is used commercially as catalyst in petroleum refinery because of its high concentration of active acid sites, its high thermal stability and high size selectivity. Zeolite-Y is a synthetic analog to the mineral faujasite and crystallizes with cubic symmetry. It has crystal sizes in the approximate range of 0.2-0.5µm and pore diameter of 7.4À. It thermally decomposes at 793oC (Htay et al, 2008).