Abstract
The article discusses the composition, physicochemical properties of used motor oils, and the possibilities of their utilization as fuel after recycling. The environmental impact of used motor oils and the ecological and economic significance of their recycling were analyzed. The study determined the main physicochemical characteristics of used motor oil and investigated its metal content. The results showed that the kinematic viscosity of the used oil was 9.5 mm²/s, its density was 0.9001 g/cm³, and its flash point was 165°C. Copper, iron, zinc, and cadmium were detected in the oil samples, while lead was not found. The obtained results confirmed the technical feasibility of using pretreated used motor oils as boiler fuel or as a component of hydrocarbon fuels. Recycling used motor oils contributes to the conservation of petroleum resources, reduction of waste volumes, and mitigation of environmental pollution.