Composition of aromatic products in the catalytic degradation of the mixture of waste polystyrene and high-density polyethylene using spent FCC catalyst

Abstract

In this chemical recycling process, spent FCC catalyst used had an advantage with an economical and environment aspect, such as a low catalyst price in liquid-phase reaction and a reuse of waste catalyst. The characteristics of oil product and its aromatic product distribution, as a function of reaction time in the reactor and also proportion of HDPE and PS in the mixture, were compared. Main products obtained were light hydrocarbons within the gasoline range that were mainly produced during initial reaction time. The formation of aromatic products such as styrene and ethylbenzene as major components depended appreciably on the reaction time, as well as the composition of HDPE and PS in the mixture used for degradation. For the distribution of C 9–C 12 alkylaromatic components as by-products, methylstyrene (C 1-styrene) and isopropylbenzene (C 3-benzene) components were the main products formed by β-scission and hydrogen transfer of PS, while the rest of alkylaromatic products showed very low fraction being 1% or less.