Improvement of Combustion Characteristics of Jatropha Curcas Oil by Water Emulsification -Combustion Analysis in Pre-Combustion Chamber Type Diesel Engine

From the viewpoints of limited fuel oil resources and the problem of global warming, possible alternatives to fossil oil have been widely studied in recent years. Jatropha curcas oil is one of the vegetable oils considered as possible alternatives to fossil fuel. It is effective in reducing CO2 emissions with its carbon-neutral characteristic, and it does not contribute to the problem of increasing food prices because its seeds are poisonous and are thus inedible. This study aims to clarify whether water emulsification can improve the combustion characteristics of Jatropha curcas oil. The experiments were conducted with water-to-Jatropha curcas oil ratios of 5%, 10%, 15%, and 20% by weight, and combustion analysis was carried out. The test engine used was a 4-stroke pre-combustion chamber type diesel engine which can generally run on poor quality fuels. Combustion pressure and fuel injection pressure as well as exhaust gas emissions were measured. It was shown that water emulsification resulted in the improvement of thermal efficiency and the reduction of NOx emissions and carbon deposits.