Non-catalytic and Catalytic Pyrolysis of Low Density Polyethylene LDPE Plastic Waste Into Fuel Ranged Hydrocarbons Using Nigerian Local Clay Composites

Abstract

Plastic utilisation and plastic waste accumulation is rising in recent times mostly in developing countries. The utilization of modified and unmodified Nigerian bentonite clay as catalyst for preparation of fuel-ranged hydrocarbons from low-density polyethylene (LDPE) sachet wastes by pyrolysis was investigated. Pyrolysis of LDPE was done using locally fabricated semi-batch reactor condenser column. The products were characterized using Fourier transform infra-red spectroscopy (FTIR) and gas chromatograph with a flame ionisation detector (GC-FID). Physicochemical properties of the products were determined using standard analytical methods. The products from non-catalysed contained mostly saturated hydrocarbons compared to that of the catalytic process which contained more branched-chain hydrocarbons and mono-substituted aromatics. Physicochemical properties of the product from non-catalytic process showed resemblance to those of kerosene and diesel fuel while the properties of products from catalytic pyrolysis closely approximates those of commercial gasoline. This implies that the catalytic process gave products that were more suitable as fuels for auto engine which require higher octane number based on their naphthenic and aromatic content.