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 successfully carried out. Waste Low Density Polyethylene (LDPE) and waste High Density Polyethylene (HDPE) samples were subjected to thermal pyrolysis in an electric tubular furnace. A study was also carried out to investigateFirst, the effect of heating rate on the volume of the gaseous products was studied. Previous research by other authors showed appreciable gas production occurred at a minimum heating rate of 20oC/min as such hHeating rate valuess of 22oC/min, 26oC/min and 32oC/min were adoptedused . It showed thatwith results showinged that a higher heating rates 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. %.