Effect of water and methanol fractions on the performance of a CI engine using animal fat emulsions as fuel
Résumé
The influence of water and methanol (W/M) fractions on the performance of a compression ignition engine fuelled with animal fat (obtained from duck) emulsions is studied. A single cylinder air-cooled, direct injection diesel engine developing a rated brake power output of 2.8 kW at 1500 r/min is tested using diesel neat animal fat, and animal fat emulsions with different fractions of W/M. Results show reduced peak pressure with neat animal fat when compared with diesel. Animal fat emulsions result in increased peak pressure with increased W/M fractions. Ignition delay is quite high with neat animal fat. Increase in W/M amounts in the emulsions further increase the ignition delay. Heat release pattern shows improved combustion rates with animal fat emulsions at all W/M fractions when compared with neat animal fat. Drastic reduction in smoke emission from 3.6 m(-1) with neat animal fat to a minimum of 0.5 m(-1) is achieved with the animal fat emulsion at the maximum W/M fraction. NO emission is found to be lower with neat animal fat than with neat diesel. Animal fat emulsions further reduce NO emission at all W/M fractions. Hydrocarbon and carbon monoxide emissions are also reduced significantly with animal fat emulsions at all W/M ratios when compared with neat animal fat. In general, animal fat emulsions with different W/M fractions show considerable reduction in all emissions and improvement in engine performance when compared with neat animal fat. Emulsion of 10W10M2S83 (i.e. 10 per cent of water, 10 per cent of methanol, and 2 per cent of span 83 by volume) is found to be the best among the three tested emulsions for optimum performance and emissions.