Cleaner emissions from a DI-diesel engine fueled with mahua oil and low carbon ethanol-hydrogen in dual fuel mode

Abstract

This work is all about utilization of more than two low carbon fuels in a diesel engine with a main objective of reducing harmful emissions. Initially, test engine was tested with a non-petroleum-based fuel namely mahua oil, under different load conditions. In the second phase of the work, test engine was modified into dual fuel mode with slight modification in the intake manifold for the admission of a low carbon high octane primary fuel namely ethanol. The engine was tested by varying the ethanol energy share (EES) from 5% to the point at which engine tends to knock at 100% and 40% of the maximum engine power output. Finally, an attempt was made to induct a zero carbon high octane fuel (i.e., hydrogen) in the intake manifold of the dual fuel engine operated with mahua and ethanol and tested for the behavior. Experimental results claimed that inclusion of ethanol improved the brake thermal efficiency (BTE) only at the higher loads. Optimized EES at 100% load conditions was identified as 15%. It is found that injection of ethanol significantly reduced the harmful emissions like smoke and oxides of nitrogen at the price of increased hydrocarbon and carbon monoxide emissions. It is also inferenced that BTE was improved further with the increases of hydrogen flow rate at peak load. Interestingly all the carbon-based emissions were drastically reduced with the inclusion of hydrogen. However, the oxides of nitrogen emission were found to be increased with increase of hydrogen flow rate.