Experimental analysis of the morphology and nanostructure of soot particles for butanol/diesel blends at different engine operating modes

In order to comply with strict emission standards, a reduction in diesel particle matter emissions can be addressed by minimizing particle formation and by optimizing particle oxidation in the combustion chamber and in the exhaust and diesel particulate filter systems. The characterization of soot morphology and nanostructure is necessary to understand the soot formation and oxidation processes. Furthermore, understanding these characteristics is important because they affect the aerodynamic behavior of diesel particulate matter in the exhaust system, diesel particulate filter systems, and the environment. This study aims to investigate the influence of fuel oxygen content and engine operating modes on the morphology and nanostructure of soot particles. The oxygen content in the fuel was varied from 0% to 4.32% and 6.48% by using diesel and 20 and 30% butanol blends (by volume) with diesel. As the oxygen content increased, corresponding nanostructure characteristics fringe length and separation distance increased and fringe tortuosity decreased. Changes to the nanostructure properties will have an influence on the operation of diesel particle filters, particularly during the regeneration processes. However, other characteristics such as the influence of these fuels on particle mass and number emissions, performance parameters, and gaseous emissions will also have a significant influence on implementing these fuels in modern diesel vehicles.