Effect of Butanol Addition on Performance, Combustion Stability and Nano-Particle Emissions of a Conventional Diesel Engine

This study presents the experimental investigation of performance, combustion, gaseous and nano-particle emission characteristics of conventional compression ignition (CI) engine fueled with neat diesel and butanol/diesel blends. The experiments were conducted for neat diesel, 10%, 20% and 30% butanol/diesel blend on the volume basis at different engine loads. Combustion characteristics were investigated on the basis of in-cylinder pressure measurement and heat release analysis. The in-cylinder combustion pressure traces were recorded for 2000 consecutive engine combustion cycles for computation of heat release and different combustion parameters. Combustion stability analysis is conducted by analyzing the coefficient of variation of in indicated mean effective pressure (IMEP) and total heat release (THR). Wavelet analysis is also used for analyzing the temporal variations in IMEP data series. For the analysis of particle size and mass distributions of engine exhaust particles, electrical mobility based fast particle sizer is used in the present study. Results indicate that the addition of butanol in the diesel fuel reduces the total particle number concentration. Additionally, blending of butanol in the diesel fuel has a potential to reduce the carbon monoxide (CO), nitric oxide (NO), smoke opacity emissions as well. However, HC emissions increase with the addition of butanol in the diesel fuel.