Influence of palm oil biodiesel on the chemical and morphological characteristics of particulate matter emitted by a diesel engine

The influence on the chemical composition of the particle matter (PM) produced in an automotive diesel engine operated with palm biodiesel (PB) and its blends with diesel fuel were studied. The opacity index showed a decrease on the PM emitted by the engine when palm biodiesel amount increased in the fuel, a result that also agrees with the amount of PM collected in filters. Similarly, the PB concentration did not affect the average size of PM emitted compared to diesel. But, it seems to be that biodiesel and its blends tend to produce PM with a higher number of small particles. The chemical composition of PM obtained from PB blends and pure PB were similar to those reported before; however no correlation with biodiesel concentration was found, except for the evident reduction on sulfur content in particle matter, a fact that can be associated with a fuel dilution effect.