Low Carbon Flower Buildup, Low Smoke, and Efficient Diesel Operation with Vegetable Oils by Conversion to Mono-Esters and Blending with Diesel Oil or Alcohols

The purpose of this investigation is to evaluate the feasibility of rapeseed oil and palm oil for diesel fuel substitution in a naturally aspirated DI Diesel engine is evaluated. Means to reduce the carbon deposit buildup in vegetable oil combustion is found. In the experiments, the engine performance, exhaust gas emissions, and carbon deposits are measured for a number of fuels: rapeseed oil, palm oil, methylester of rapeseed oil, and these fuels blended with ethanol or diesel fuel with different fuel temperatures. Both of the vegetable oil fuels generate an acceptable engine performance and exhaust gas emission levels for short term operation, but they cause carbon deposit buildups and sticking of piston rings after extended operation. Practical solutions to overcome the problems are: increasing the fuel temperature to over 200/sup 0/C, blending 25 vol % diesel fuel in the vegetable oil, blending 20 vol % ethanol in the fuel, or converting the vegetable oils into methylesters.