Synthesis and Characterization of Liquid Fuels from Waste Plastic Polymers via Catalytic Pyrolysis in Case of Legambo Wereda, South Wollo, Ethiopia

The aim of this study was to convert HDPE and PET waste plastics into valuable hydrocarbon
liquid fuel via catalytic pyrolysis technique using silica-alumina as a low-cost catalyst
synthesized from rice husk and aluminum oxide. HDPE and PET waste plastics were
catalytically degraded in a muffle furnace at a temperature of up to 450 °C using silica-alumina
catalyst in catalytic pyrolysis of the same feedstock for optimum catalyst-to-plastic ratio of 1:3
according to literatures. Optimum yield was obtained at this catalyst-to-plastic ratio with a yield
of 50.90, 6.10%, 43.00 wt% for liquid, solid and gaseous products, respectively for HDPE waste
plastics whereas for PET only solid residue was obtained. The catalyst was characterized by
XRD, FTIR and GC-MS. The ultimate and proximate analysis of the HDPE feed carried out
gave combustible moisture content of 5.70 %, fixed carbon of 11.56%, Ash content of 10.05%,
Volatile matter content of 72.69%, fixed carbon content of 11.56%, calorifc value of
46.70 MJ/kg and elemental composition with carbon (83.65%), hydrogen (12.72%), oxygen
(1.50%), sulphur (0.70%), chlorine (2.25%), and nitrogen (1.37%). The properties determined
were density, viscosity, flash point, fire point, pour point, and calorific value for HDPE feed
stock. Whereas, the ultimate and proximate analysis of PET feed gave moisture content of
4.74%, ash content of 11.67%, volatile matter content of 73.53% and fixed carbon content of
9.06%. The results suggest that catalytic pyrolysis produced liquid products for HDPE feed stock
only, whose properties are comparable to conventional fuels (gasoline and diesel oil).