Performance and Emissions Characteristics of a Naturally Aspirated Diesel Engine with Vegetable Oil Fuels

The performance and emissions characteristics of a direct injected, naturally aspirated diesel engine operating on 100 percent sunflower oil, 100 percent peanut oil and 50 percent (by volume) mixtures of either sunflower oil or peanut oil with #2 diesel fuel were compared to baseline results using #2 diesel fuel. Without recalibration of the rotary injection pump, the higher fuel densities and viscosities of peanut oil and sunflower oil caused fuel flow and energy delivery increases that yielded power and emissions increases. With the fuel flow adjusted to provide equal fuel energy input, engine power and thermal efficiency decreased slightly, while emissions increased slightly.