Influence of N-Butanol-Diesel Fuel Blends on the Performance Characteristics of a Four Stroke, Compression Ignition Engine

Aims: This study investigates the impact of blending n-butanol with diesel fuel on the performance of a single-cylinder, 4-stroke diesel engine under varying engine loads. Study design: The performance assessment followed SAE J1349 on a Tec-Quipment TD110-115 4-stroke engine at 1500 rpm with varying loads and fuel samples. Place and Duration of Study: The study was conducted for 2 months the at Automotive Engineering Technology Workshop, Federal Polytechnic, Bauchi Nigeria. Methodology: The SAE J1349 test protocol was followed, using diesel fuel (D95) and different blended fuel samples (D90, D85, D80, D75, and D70). While diesel fuel generated higher brake power due to its higher calorific value, the D95 blend demonstrated comparable performance to diesel fuel across all parameters. Results: The brake power of the D95 blend initially decreased by 69.7% and then increased as the load increased to 2500g and 3000g, indicating improved combustion due to oxygenation. The D95 blend exhibited lower fuel consumption compared to diesel fuel, although blends with higher n-butanol percentages showed increased brake-specific fuel consumption due to lower calorific values, densities, and viscosities. Under maximum load, the D95 blend exhibited higher exhaust gas temperature and heat loss, reflecting the increased fuel quantity required for additional power. Lower heat losses at lower loads were attributed to factors such as lower calorific values, n-butanol's heat of vaporization, temperature differentials between the exhaust and ambient conditions, and engine size. Conclusion: The engine load has diverse effects on parameters across different fuel samples. D95 exhibits similar performance to diesel, yet discrepancies arise, especially with higher n-butanol content at lower loads.