Catalytic pyrolysis of waste tire over Y-based catalysts: synergistic effect between Pd-Pt

Abstract

The waste tire pyrolysis is the promising way to solve the problems of insufficient fuel resources. Its products consist of gas and oil with insufficient qualities for direct uses in engines. Using the bimetallic, Pd and Pt, on Y-zeolite was expected to increase the quality and quantity of pyrolytic products due to the synergistic effect between the two metals. In this work, two different methods: co-impregnation (Pd-Pt/Y) and successive impregnation techniques (Pd*-Pt/Y and Pd-Pt*/Y ; the asterisk indicates the metal impregnated first) were used for preparing the bimetallic catalysts. The amounts of Pd per total metals (a[subscript Pd]) were relatively varied as 0, 0.2, 0.4, 0.6, 0.8, and 1% wt for both sets of catalysts prepared. The objectives were to examine the quantity and quality of the pyrolytic products and to verify the effective composition of catalyst for the production of high quality products. Among the significant results, using the bimetallic catalysts produced high quality oil with a high saturated hydrocarbon and low sulfur content due to the synergistic effect between the Pd and the Pt. The Pd-Pt*/Y at aPd 0.2 and 0.8 with high metal dispersion, wide size distribution, and high sulfur tolerance, can expectedly produce a high-stable fuel with the reason that these ration gave a large amount of saturated hydrocarbons and low number of aromatics and sulfur contens.