Investigations on a CI Engine Using Animal Fat and Its Emulsions With Water and Methanol as Fuel

Performance of a compression ignition engine fuelled with animal fat and its emulsions as fuel is evaluated. A single cylinder air-cooled, direct injection diesel engine developing a power output of 2.8 kW at 1500 rev/min is used. Base data is generated with standard diesel fuel. Subsequently, animal fat is modified into its emulsions using water and methanol. Comparison is undertaken with diesel, neat animal fat and its emulsion as fuels.

Results show improved performance with animal fat emulsions as compared to neat fat. Peak pressure and rate of pressure rise are increased with animal fat emulsions due to improved combustion rate. Heat release pattern shows higher premixed combustion rate with the emulsions. Higher ignition delay and lower combustion duration are found with animal fat emulsions than neat fat.

Drastic reduction in black carbon smoke and NO are found with the emulsions as compared to neat animal fat and neat diesel. The reduction in smoke level is from 3.6 m^-1 with neat fat to 0.9 m^-1 with animal fat emulsions at peak power output. It is 6.3 m^-1 with diesel. NO value is found as 18.7 g/kWh with diesel and 18.3 g/kWh with neat fat whereas it is 2.6 g/kWh with the emulsions. Hydrocarbon and carbon monoxide emissions are found as high with neat animal fat as compared to diesel. These emissions are also reduced considerably with the emulsions of animal fat. On the whole it is concluded that animal fat emulsions with water and methanol can be used as fuel in a compression ignition engine with significant reduction in exhaust emissions and improved performance as compared to neat fat.