Catalytic conversion of waste high-density polyethylene into useful hydrocarbons

Waste high-density polyethylene (HDPE) was catalytically degraded using CaCO3 as a basic catalyst. Various parameters like temperature, catalyst to polymer ratio (cat/pol) and reaction time were explored in order to find out optimum reaction conditions. Total conversion of 97.20% was achieved with 52.33% oil yield and 53.84% oil selectivity. Sufficient quantity of the oil product was collected for further physicochemical study. The oil obtained was fractionated at different temperatures and physical parameters were studied for all the fractions including parent catalytic oil. The ASTM distillation study of the catalytically derived oil showed that its 40% fraction was in the boiling point range of light naphtha, 24% fraction was in the range of heavy naphtha and 36% fraction was in the boiling point range of middle distillate. The oils obtained were analyzed by GC/MS to find out its composition. Major constituent hydrocarbons were found to be in the range of C-7-C-28 distributed in various fractions derived at different temperatures. Different fractions showed varied compositions with constituents common to two or more sample fractions showing overlap of the distillation ranges. Comparing the physical parameters of the sample oils with standard fuels it was observed that the collected fractions were either in the range of gasoline, kerosene or diesel oil. (C) 2012 Elsevier Ltd. All rights reserved.