THE INFLUENCE OF FUEL ADDITIVES ON THE FORMATION OF CARBON DURING COMBUSTION

We show that the fuel additive ferrocene leads to the formation of con densation nuclei in the combustion zone prior to the formation of carb onaceous particles. The condensation nuclei most likely are iron oxide s. The carbonaceous matter preferentially condenses at the surface of the iron oxide nuclei where it is burnt in the last stage of the combu stion. Similar results are obtained if palladium aerosol instead of fe rrocene vapor is added to the fuel. Under the ideal conditions of a la minar acetylene flame diluted with argon and seeded with ferrocene alm ost complete burnout of the carbonaceous matter is achieved. In turbo- charged heavy duty diesel construction engines, the same basic phenome na are observed, yet the burnout is Far from complete. (C) 1998 Elsevi er Science Ltd. All rights reserved.