Influence of Ethanol Blend Addition on Compression Ignition Engine Performance and Emissions Operated with Diesel and Jatropha Methyl Ester

The world is looking for an alternate fuel to replace the existing petroleum based products due to the depletion of natural resources and it has been projected for future unavailability and fluctuation of oil price in an international market. The EU directive targets 20% of all fuel should be from bio-fuels by 2020. There is a need to improve performance and emission levels in Compression Ignition (CI) or Spark Ignition (SI) engines to comply with stricter automotive norms and regulations due to the global warming issues. This research work is influenced by these factors and is expected to motivate the governing bodies to implement directives with higher bio fuel blends.

In this context, a four stroke, single cylinder naturally aspirated (NA) direct injection (DI) diesel engine with 8 BHP @ 1500 rpm coupled with water cooled eddy current dynamometer was used for the experiments. The performance and emission tests were carried on Compression Ignition Engine using blends (B20, B40, B60, B80 and B100) of Jatropha Methyl Esters (JME) and diesel. Also 5% of Ethanol was injected into the intake manifold by port injection method with the assistance of a mechanical fuel injection pump. It is premixed with intake air and can be considered as homogeneous charge combustion. This ethanol injection assisted in getting an improved combustion process in diesel and JME blends as well.

The engine performance was increased to about 3-5% by addition of 5% ethanol in CI engine fuel with diesel and Jatropha Methyl Ester blends. Also a reduction of emissions like Carbon monoxide (CO), Total Hydrocarbon (THC), and Smoke were achieved about 51%, 40% and 43% respectively. However NOx emission was 47% increased in nature at high engine load. These results were compared with the neat diesel fuel and it may be due to presence of oxygen contents in its fuel molecular structure and also it was observed from combustion of fuel in an engine.