Production and Characterization of Liquid Fuel From Copyrolysis of KIoT Wastewater Treatment Sludge and Plastic Waste (LDPE)

As a result of its increasing industrialization, Ethiopia generates a massive volume of waste sludge and plastic garbage. This trash can come from a variety of places, including factories, lodging establishments, chemical plants, academic institutions, and other industrial facilities. This study investigates a copyrolysis method for producing liquid fuel from these wastes at temperatures of 350°C, 450°C, and 550°C, reaction durations of 15, 30, and 45 min, and KIoT‐wast water treatment sludge (WWTS)/low‐density polyethylene (LDPE) ratios of 25%, 50%, and 75%. Proximate and elemental analyses were performed in accordance with ASTM standards, and thermal degradation behavior was assessed using thermogravimetric analysis (TGA). Product characterization was carried out using gas chromatography‐mass spectrometry (GC–MS) and FTIR techniques. The results demonstrated that blending LDPE with WWTS substantially influenced thermal decomposition patterns and product distribution. A maximum bio‐oil yield of 66 wt.% was obtained at 450°C with a 50% LDPE blend and a 30 min residence time. TGA investigations demonstrated that KIoT‐WWTS and LDPE interact synergistically, lowering char formation while enhancing volatile release. FTIR analysis found a high absorption at 2921.5 cm −1 , indicating hydrocarbon‐rich functional groups like diesel fuel. GC–MS confirmed increased hydrocarbon content in bio‐oil with 50% LDPE blend. The bio‐oil had a high calorific value (43,280 kJ/kg) and low oxygen concentration (1.48 wt.%), resulting in fuel stability and quality comparable to transport‐grade diesel. These findings show the potential of copyrolysis of KIoT‐WWTS and LDPE to produce high‐value liquid fuels, hence allowing for energy recovery and environmental mitigation.