Main Article Content
Effect of blending on fuel gas composition of pyrolysed plastic wastes
Abstract
An investigation into the effects of blending on the gaseous product distribution of plastic wastes was carried out. Waste Low Density Polyethylene (LDPE) and waste High Density Polyethylene (HDPE) samples were subjected to thermal pyrolysis in an electric tubular furnace. First, the effect of heating rate on the volume of the gaseous products was studied. Heating rate values of 22oC/min, 26oC/min and 32oC/min were used with results showing that a higher heating rate favoured the production of non-condensable gases in HDPE but caused a persistent decrease in LDPE. The investigation into the effects of blending was then carried out at a temperature range of 480oC – 600oC and heating rate of 22oC/min using blends of 0%, 20%, 40%, 50%, 60%, 80% and 100% LDPE in HDPE. The gaseous product was analysed by gas chromatography and results obtained showed a similarity in hydrocarbon product distribution for both LDPE and HDPE gas products. 100% LDPE showed a composition of 21.84%, 47.39%, 20.78%, 8.40%, and 1.59%; and 100% HDPE showed a composition of 18.88%, 46.91%, 22.89%, 9.59%, and 1.73% for C1, C2, C3, C4, and C5+ hydrocarbon molecules respectively. The presence of LDPE in blends of LDPE-HDPE favoured the production of C1 up to 99 mol. %.
Keywords: pyrolysis, waste plastics, LDPE, HDPE, fuel gas