An experimental analysis of diesel engine characteristics using diesel-cetane improver blends

The majority of the previous studies which use a cetane enhancer (CE) with diesel engine fuels are based on diesel-biodiesel or diesel-alcohol fuel blends, where the addition of biodiesel/alcohol fuel to neat diesel (D100) reduces its cetane number significantly. The studies which investigate diesel engine performance using CE blended with D100 are scarce in the reported literature. This study is aimed at bridging this research gap, by investigating diesel engine outcomes using D100 fuel blended di-tert-butyl peroxide (DTBP); a CE which was added to D100 in proportions of 0.7% and 1.5% by volume respectively. Experiments were performed at 80% engine load and varying engine speed. The results demonstrate that increasing engine speed worsens engine performance and emission characteristics due to shorter cycle time and increased friction losses. The addition of DTBP is found to be highly effective in terms of improving engine performance and emission characteristics except smoke emissions especially at higher engine speeds. However, the effectiveness of DTBP in terms of lowering the ignition delay (ID) declines when its concentration in D100 is increased from 0.7% to 1.5% compared to the case when it is added to D100 by 0.7%. At 1600 rpm, the addition of DTBP by 1.5% into D100 reduces brake specific fuel consumption (BSFC) by 5.4% while carbon monoxide (CO), nitrogen oxides (NO x ) and hydrocarbon (HC) emissions dropped by 65.0%, 15.8% and 45.7% respectively. However, smoke emissions are increased due to the addition of CE to D100.