ENVIRONMENTAL IMPACTS OF BLEND FUELS ON HUMAN HEALTH

Background: The growing demand for energy, coupled with the adverse environmental impacts of fossil fuels, has prompted the exploration of renewable and waste-derived alternatives. Waste cooking oil (WCO), a widely available byproduct of the food industry, has emerged as a sustainable feedstock for biofuels. However, its direct use in diesel engines poses challenges due to high viscosity and poor volatility. The addition of oxygenated alcohols such as n-pentanol has been suggested as a potential solution to improve fuel properties and reduce harmful exhaust emissions. Objective: This study aimed to evaluate the performance and exhaust emission characteristics of a compression ignition (CI) engine fueled with diesel-WCO-n-pentanol blends, with emphasis on carbon monoxide (CO), carbon dioxide (CO₂), and particulate matter (PM) emissions. Methods: Experimental investigations were conducted using a single-cylinder, water-cooled, horizontal CI engine operating at a constant speed of 1300 rpm and steady load conditions. Three fuel samples were tested: pure diesel (DF100), a binary blend of 85% diesel and 15% WCO (D85WCO15), and a ternary blend of 80% diesel, 15% WCO, and 5% n-pentanol (D80WCO15Pe5). The blends were prepared through splash blending and homogenized at 4000 rpm for 30 minutes. Exhaust gas analyzers were used to measure CO, CO₂, and PM1.0/PM2.5 concentrations over engine operation hours. Results: The binary blend (D85WCO15) increased CO emissions to 0.12% compared to 0.07% for diesel, while the ternary blend (D80WCO15Pe5) reduced CO to 0.035%. CO₂ emissions increased by 0.25% for D85WCO15 and 0.70% for D80WCO15Pe5 relative to diesel. PM emissions decreased by approximately 10% with D85WCO15 and by 30% with D80WCO15Pe5 compared to diesel, with consistent reductions observed for both PM1.0 and PM2.5 fractions. Conclusion: The addition of n-pentanol to diesel-WCO blends improved combustion efficiency, resulting in lower CO and PM emissions but higher CO₂ output. These findings indicate that ternary blends represent a practical strategy for waste valorization and emission reduction in CI engines.