Coconut Oil Based Hybrid Fuels as Alternative Fuel for Diesel Engines

Problem statement: The use of vegetable oils as a fuel in diesel engines causes some problems due to their high viscosity compared with diesel. Various techniques and methods are used to solve the problems resulting from high viscosity. Approach: One of the techniques is the preparation of a microemulsion fuel, called a hybrid fuel. In this study, hybrid fuels consisting of coconut oil, ethanol and octan-1-ol were prepared with an aim to test their suitability as a fuel for diesel engines. Density, viscosity and gross calorific values of these fuels were determined and the fuels were used to run a direct injection diesel engine. The engine performance and exhaust emissions were investigated and compared with that of diesel and coconut oil. Results: The experimental results show that the engine efficiency of the hybrid fuels is comparable to that of diesel. As the percentage of ethanol and/or octan-1-ol increased, the viscosity of the hybrid fuels decreased and the engine efficiency increased. The exhaust emissions were lower than those for diesel, except carbon monoxide, which increased. Conclusion/Recommendations: Hence, it is concluded that these hybrid fuels can be used successfully as an alternative fuel in diesel engines without any modifications. Their completely renewable nature ensures that they are environmentally friendly.