Characteristics of Diesel Smoke Suppression with Soluble Fuel Additives

Abstract

This research analyzes the nature of diesel soot suppression with soluble additives, aiming at efficient and sootless diesel combustion. A large number of additives were systematically examined for soot reduction and it was found that Ca and Ba were the most effective. The soot reduction ratio is expressed by an exponential function of the metal mol-content in the fuel, depending on the metal but independent of the metal compound. A rise in the excess air factor or gas turbulence in the combustion chamber increases the weight of a coefficient in the function, resulting in a larger reduction in soot with a fuel additive. In-cylinder soot sampling showed that the additive acted as a catalyst not only to improve soot oxidation but also to suppress soot formation.