Combustion and emission characteristics of a common rail diesel engine run with n-heptanol-methyl oleate mixtures

Abstract

The purpose of the current study is to inspect the influence of the addition of n-heptanol with methyl oleate biodiesel fuel at various blending ratio on the combustion and emission parameters of a common rail diesel engine to attain their optimum ratio. The n-heptanol is added at 10%, 20%, 30% and 40%, which are denoted as H10B, H20B, H30B, and H40B respectively. Studying these mixtures stability, all blends were kept under observation for more than one month, and they were stable at ambient conditions. The measured physicochemical properties of n-heptanol-methyl oleate blends show that there is a reduction in their kinematic viscosity and cetane number. The results for methyl oleate illustrate that the peak pressure is slightly decreased by about 4%, while the soot and NOx emissions are diminished by about 2% and 6% respectively compared to pure diesel fuel. The soot and NOx emission are reduced by up to 90% and 15% respectively when adding n-heptanol. The bsfc is enlarged by around 5% methyl oleate while it is enlarged by 15% for n-heptanol- methyl oleate mixtures. It can be summarized from the combustion and emission results that the proposed mixing ratio of n-heptanol and methyl oleate fuel is H20B.