Overview of the impact of oxygenated biofuel additives on soot emissions in laboratory scale

Soot has harmful effects on the environment and human health. The formation process of soot includes six steps: fuel pyrolysis, soot nucleation, coalescence, surface growth, aggregation, and soot oxidation. However, the formation of soot is very complex and is influenced by factors such as fuel type, combustion conditions, and environmental temperature. Oxygenated fuels additives have a positive effect on reducing soot emissions, but recent studies have shown that oxygenated fuels can lead to an increase in the number of small particles of soot. In this paper, the effect of oxygenated fuel additives such as alcohol, ether, and esters on soot emissions is discussed in terms of the mechanism of soot formation. Subsequently, the role of after-treatment systems in reducing soot emissions is summarized. This work can update our understanding of the impact of oxygenated fuels on soot emissions.