FUEL GASES FROM WASTE HIGH DENSITY POLYETHYLENE (HDPE) VIA LOW TEMPERATURE CATALYTIC PYROLYSIS

Abstract

This study was carried out in order to obtain useful gases from waste polyethylene of high density polyethylene (HDPE) at low temperature pyrolysis. This was carried out by adapting a cylindrical pressure cooking pot of height 30.00 cm with an internal diameter 31.50 cm. The pyrolysis reaction was carried out with the influence of Fluid Catalytic Cracking (FCC) catalyst. The gases evolved during the pyrolysis reaction were collected using Tedlar bags and analysed using a BUCK 530 Gas Chromatograph. The pyrolysis reaction with fresh FCC catalyst at 150 °C and 250 °C using catalyst/sample ratio of 1:8 showed aliphatic hydrocarbons in the range of C1-C9 with total concentrations of 84.3969 and 526.4070 ppm respectively. The corresponding values obtained at 150 °C and 250 °C for HDPE using catalyst/sample ratio of 1:16 were obtained as 495.4315 and 385.5101 ppm respectively. The reaction with spent FCC catalyst at 150 °C and 250 °C using catalyst/sample ratio of 1:8 gave the total concentrations of 112.7276 ppm and 87.3531 ppm respectively. The corresponding values obtained at 150 °C and 250 °C using catalyst/sample ratio of 1:16 were 116.9178 and 109.4314 ppm respectively. Production of useful gases from waste polyethylene gave reasonable amounts of gaseous products which can serve as feed stock and as fuel gas.