Tertiary recycling of waste polyethylene to fuel gases via low temperature catalytic pyrolysis

Abstract

Pyrolysis of low density polyethylene (LDPE) was carried out by adapting a cylindrical pressure cooking pot of height 30.00 cm with an internal diameter of 31.50 cm as the reactor. The pyrolysis reaction was carried out with the influence of Naphtha Hydro treating Unit (NHU) catalyst. The gases which evolved were collected using Tedlar and analysis was done with the aid of a BUCK 530 Gas Chromatograph. The pyrolsis reaction with spent NHU catalyst at 150 °C and 250 °C using catalyst/sample ratios of 1:8 and 1:16 for all the three samples showed aliphatic hydrocarbon in the range of C1 – C9. Results showed total concentrations of gases (ppm) to be 109.8282 and 53.1022 for LDPE, 96.3748 and 140.4273 for PET and 81.6393 and 49.0464 for HDPE respectively. The corresponding values (ppm) were obtained for LDPE, PET, and HDPE at 150 0C and 250 0C using catalyst/sample ratio of 1:16 to be 88.1075 and 56.1038, 81.2315 and 624957, 48.8769 and 53.8048 respectively. The fuel gases revealed mainly C1 – C9 aliphatic hydrocarbons which can be fractionated into fuel gases, gasoline range product.