Non-Edible oils Blends in Direct Injection Diesel Engines

The use of non edible oils blend in direct injection diesel engine shows its potential to reduce or control the NOx emissions. Combustion analysis of non edible and non edible blends revealed that the blends had a shorter ignition delay than diesel alone, at both full and light load, and a lower premixed burn fraction at full load. However, the diffusion burn rates were similar. The shorter ignition delay due to high cetane number of non edible oil blends has been suggested as being one of the causes of NOx increase the peak pressure and temperature increase in flame temperature in either pre mixed or diffusion burn has been followed by subsequent increase in NOx emission. This was due to reduction of carbonaceous soot concentration. The performance characteristics of an engine such as brake thermal efficiency, brake specific fuel consumption, brake power and engine torque were not much affected, up to a blend of 20% with neat diesel. The Co and particulate emissions were found to be decreasing with the % increase in blend with a subsequent increase of NOx. Thus the blending of fuel is being limited to 20% in majority of cases to obtain optimum performance and emission characteristics. This paper suggests about by using various types of non edible oils as fuel and blends directly in diesel engines by modifying properties by injecting or Trans-esterification.