Gasoline Fuel Production via Catalytic Cracking of Low-Density Waste Plastics Dissolved in Gasoil

Abstract

In the present work, catalytic cracking of low-density polyethylene (LDPE) dissolved in gasoil was investigated with a laboratory scale fluid bed reactor using commercial zeolite Y as catalysts for gasoline fuel production and waste plastics recycling. The liquid products chiefly consist of paraffins, isoparafins, olefins, naphthenes, and aromatics compounds. At a conversion of 75%, within gasoline pool (C5-C12), C5 and C6 were the principal components, and they accounted for approximately 25-30wt%, dependent of the catalyst applied. It is noted that hexane yield dominated around 50% of the total paraffins. The hydrothermal deactivated treatment (HDT) catalysts exhibit higher selectivity for i-C5 in the isoparafins, but it shows lower selectivity for aromatic compounds in comparison with that obtained using equilibrium catalysts (ECAT) catalyst under the same condition, resulting from their different acidity density and strength. Most aromatic compounds are in the range of C6-C10 with a benzene content less than 0.25wt%. The hydrocarbon composition of gasoline obtained from this work satisfied the current regulatory requirement of the commercial gasoline fuel. This work confirmed that simultaneous production of gasoline fuel and recycling of waste plastics by mixing a proper amount, i.e., 2.5 wt%, of LDPE with gasoil as feedstocks using the existed FCC technology is a highly practical route.