Development of industrialized Pd/beta-based catalysts for waste tire pyrolysis

Abstract

Catalytic waste tires pyrolysis is one alternative that has recieved a great deal of attention in handling many kinds of waste materials such as plastic and tires. In a previous work, 0.25 wt % of palladium supported on beta zeolite has been proven to be the best catalyst in producing naphtha range hydrocarbons. In this research, further investigation on two different Si/Al ratios of beta zeolite support and two different kinds of natural clay matrixes were studied. The agglomerated catalysts composed of various percentages of active component (5, 20, and, 40 wt %.) in the presence of alumina binder (10 wt %.) and a matrix were investigated to find the one that gave the optimum naphtha yields at a high content in the oil obtained from the catalytic pyrolysis of waste tire. According to the results, it was found that each clay matrix itself was not catalytically inactive as it helped reduce the heavy hydrocarbon content and enhanced the production of light oil fraction. The best agglomerated catalyst composition for the naphtha production, which provided the highest concentration of naphtha in the oil product, was found to be 20 wt.% of active Pd/Beta zeolite (Si/Al = 250), 70 wt. % of bentonite, and 10 wt% of a-alumina. Moreover, this agglomerated catalyst composition also gave the maximum yield of the overall naphtha produced from catalytic waste tire pyrolysis. The synergistic effect between the mild cracking activity of the matrix and the cracking activity of active component is the cause of this high naphtha selectivity.