Abstract

The environmental impact of oil-based fuels, coupled with the ever-increasing accumulation of plastic waste and used engine oil (WEO), has led researchers to search for sustainable energy alternatives that simultaneously address issues of energy security and environmental degradation. This study aims to conduct an environmental and geolife assessment of alternative fuel mixtures derived from plastic waste and used motor oil, tested in an external combustion system under controlled laboratory conditions in Najaf Governorate, Iraq. The analyses included evaluating the thermal performance and emission characteristics of fuel mixtures (PDF-WEO) in different proportions of WEO (10%, 20%, and 30%) using pyrolysis plastic fuel (PDF) mixed with used and filtered motor oil. The results showed that the 70/30 blend (PDF/WEO) achieved the highest thermal efficiency of 35.5%, while reducing carbon monoxide and suspended particulate matter emissions by 40% and 37%, respectively. Despite a 24% reduction in NO57 emissions, the study recommends further improvements. This study highlights the potential for hazardous waste to be converted into useful fuel while minimizing the associated environmental impact. The geo-biological perspective also reflects the importance of using clean fuels in areas with high population density and environmental sensitivity, highlighting the importance of circular economy practices and low-emission energy strategies. The findings support the integration of waste-derived fuels as an effective pathway towards a sustainable energy transition in arid regions such as central Iraq.

Keywords: Waste-derived fuel, Thermal efficiency, Plastic waste, Used motor oil, Environmental pollution, Biogeography, Circular economy, Iraq