Study on performance and emissions of a passenger-car diesel engine fueled with butanol-diesel blends

In this work, the commercially available diesel fuel (Bu00), butanol(20%)-diesel(80%) (by vol.) (Bu20), butanol(30%)-diesel(70%) (Bu30), and butanol(40%)-diesel (60%) (Bu40) fuels were tested. Experiments were conducted on a high-speed direct injection (DI) diesel engine for passenger-car application for varied loads at two representative engine speeds. The results showed that butanol-diesel blends slightly increased combustion pressure and accelerated burning rate. As fueled by the Bu40 blend, the maximum power output of the engine cannot be affected. Besides, butanol-diesel blends increased BSFC and brake thermal efficiency. Moreover, the effects of butanol addition on diesel engine exhaust emissions were varied with loads. Under low-load conditions, CO emissions obviously increased while NO_x emissions decreased as butanol blending ratio increased. Under high-load conditions, on the contrary, CO emissions decreased but NO_x emission increased. For the 40% butanol-diesel blend, in addition, HC emissions were higher than the neat diesel and lower percentage of butanol-diesel blends, especially at low-load. It is interesting that smoke decreased significantly at all conditions with the use of butanol-diesel blends, and the more butanol blending ratio the less smoke. Overall butanol is a potentially promising biofuel, which could be used conveniently up to high blending ratio with diesel fuel in diesel engines.