Performance and methane emissions of diesel engine operating on fuel extracted from waste engine oil

This study investigates the effect of blending conventional diesel (D) with 10% of DWL extracted from waste engine oil via thermal distillation (90%D + 10%W) on engine performance and methane emissions under low-load conditions. Experiments were conducted on a Lombardini engine operating with compression ignition across loads (2, 4, 6 kg) and speeds (1550-2150 rpm). The results show that the 90%D + 10%W blend increased the BSFC with increasing loads and reduced the BTE with increasing loads compared to conventional diesel. This can be attributed to the lower cetane number, calorific value, and other physical properties of DWL. More importantly, methane emissions were significantly reduced under optimal conditions: by 14.28% (2 kg), 27.08% (4 kg), and 9.09% (6 kg) at 1850 rpm. This demonstrates the blend's ability to reduce methane, a potent greenhouse gas, despite some minor trade-offs in efficiency, offering a sustainable pathway for recycling waste engine oil.