This study evaluated waste cooking oil (WCO), waste engine oil (WEO), and their 50:50 blend as alternative fuels using a TOYA commercial burner, analyzing thermal efficiency, emissions profile, and combustion characteristics. Results showed that the 50:50 blend demonstrated superior performance, achieving both the fastest water boiling time (5.31 minutes) and the highest thermal efficiency (19.8%). Flame temperature profiles revealed significant differences: WCO showed the lowest (420-453°C) and most variable temperatures, while WEO burned more stably at higher temperatures. Notably, the blend achieved the most consistent peak temperatures around 500°C, directly supporting its enhanced combustion efficiency. Emission measurements showed the blend's environmental advantages, producing significantly lower carbon monoxide (8.4 ppm vs 15-16 ppm for pure oils) and particulate matter (PM2.5: 412.6 μg/m³ vs WCO's 469.3 μg/m³) while maintaining moderate CO₂ output. The combination of stable high-temperature combustion, reduced emissions, and minimal residue formation confirms that blending WCO and WEO creates an efficient, cleaner-burning fuel. These findings demonstrate how waste oil blending can improve both performance and environmental impact in thermal applications.
Simpao et al. (Thu,) studied this question.