Catalytic pyrolysis of waste tire using nickel promoted catalysts and core-shell composites

Abstract

In this work, the effects of nickel-promoted catalysts and different zeolite cores of core-shell structure composite materials on the species of waste tire pyrolysis products are investigated. Ni-doped catalysts were expected to enhance of the formation of petrochemical and reduce of sulfur content in tire-derived oil. In addition, HY/MCM-41 and HBETA/MCM-41 core-shell composite were expected to reduce the formation of polycyclic aromatics and enhance the petrochemical in tire-derived oil. Furthermore, the different zeolite cores were expected to give different petrochemical selectivity. From the experimental results, nickel on different zeolite supports enhance the reduction of sulfur content in oil and promote aromatic formation, but the selectivity of hydrocarbons products and desulfurization activity depended on the zeolite supports. In order to obtain the oil with the high petrochemicals and low sulfur contents by using Ni promoter, the zeolite supports must have a suitable pore size (5.5-7 Å) and ID channel structure that allows hydrocarbons and sulfur compounds can stay inside the pore at enough contact time for forming of valuable petrochemical and sulfur removal of sulfur compounds. For the second scope of work, The HBETA/MCM-41 and HY/MCM-41 core-shell composite were successfully synthesized, the MCM-41 shell thickness of both composite were varied in the range of 50-100 nm. The both core-shell composite catalysts provide a higher cracking and sulfur removing activities and better petrochemical selectivity than the non-composite catalysts. Different zeolite cores were found to govern different petrochemical species, HY core selectively produced ethylbenzene and toluene, whereas HBETA core selectively produced benzene, ethylbenzene and toluene.