Fouling phenomena in pyrolysis and combustion processes

Several large scale processes, e.g. liquid or vapour phase pyrolysis or combustion, involve hydrocarbon feedstocks. Their common mechanistic feature is characterised by complex radical reaction systems, involving unsaturated molecules and radicals, universally recognized as precursors in fouling and soot formation. This is an important and actual research field, both for the possible improvements in the processes and for the reduction of the environmental impact of combustion. This paper analyses the strong analogies existing on the mechanism of fouling and soot formation in liquid phase pyrolysis (such as visbreaking and delayed coking), gas phase pyrolysis to produce ethylene and finally combustion process of fuel hydrocarbons. The aim of this work is to move towards the ambitious objective of obtaining a global model for the description of fouling phenomena into the equipments and soot formation in combustion.