Research of diesel soot emission of alternative fuels by combination of engine tests and laser diagnostics

Due to the increasingly stringent regulation of particulate matter (PM) emission, the research of soot emission characteristics in diesel engines has been a hot topic for years. Numerous previous studies reported that the reduction of PM emissions depends on the molecular structure of additives and blended oxygenates. Consequently, in this research, the tests of soot emission on a modified in-line 6-cylinder DAF HD Diesel engine with several selected additive and oxygenates mixed with normal diesel. Then, the measurements of soot distribution of these blends on a stationary co-flow flame equipment has been conducted by Laser-induced incandescence. Finally, comparisons of soot emission characteristics on the engine and soot formation mechanism on the burner of these blends and the corresponding explanations are proposed

Laser diagnostics of soot formation by alternative fuels

It has been reported in previous work that the reduction of particulate matter (PM) emissions from diesel engines is impacted by the molecular structure of additives and blended oxygenates. However, due to the physical and chemical complexity of the underlying processes, characterization of combustion-generated soot particles and the effects thereupon of different fuel composition are difficult to achieve. Laser diagnostics on a simple, optically accessible burner is proposed, to aid interpretation of observations in engine tests on the effect of molecular structure of additives on the sooting propensities of hydrocarbon fuels. We present measurements of the soot and poly-aromatic hydrocarbons (PAH) distributions conducted by means of Laser-induced incandescence (LII) and planar Laser-induced fluorescence (PLIF) of several kinds of blends on a stationary co-flow flame. Moreover, a comparison is made to earlier engine emission characteristics of the same blends