Impact of various blends of linseed oil-derived biodiesel on combustion and particle emissions of a compression ignition engine - A comparison with diesel and soybean fuels

This study reports on a comparative analysis of the influence of linseed oil-derived biodiesel on a compression ignition engine combustion and performance. New findings on particle emission and size distribution are presented and discussed. A low-sulfur commercial diesel fuel and soybean biodiesel were used as a reference. Engine feeding with biodiesel blends leads to slight increase (5-15%) in the maximal pressure rise rate compared to the diesel fuel accompanied by a minor rise in coefficient of variation at low loads. Combustion duration of all studied biodiesel blends is longer compared to the diesel fuel under all operating modes. At low-load operating modes, reduction in particle number concentrations under feeding with blends of the diesel fuel with soybean and linseed-derived biofuels (in 1:1 ratio by volume) is observed in the entire range of measured particle sizes. At high loads, the opposite trend is revealed: in the ultrafine particles size range ( < 90 nm), the measured particle number concentration for the biodiesel blends is substantially higher compared to diesel fuel. In contrast to soybean biodiesel, the linseed-derived blends demonstrated a trend of reduction in nitrogen oxides emission as compared to diesel at higher engine loads.