Formation of Polycyclic Aromatic Hydrocarbons in a Vertical Flow Reactor

Abstract

The profile of temperature, reagents, main reaction products, hydrocarbons and polycyclic aromatic hydrocarbons have been determined at different heights along a vertical flow reactor on which cool, blue and yellow flames of a n-heptane/oxygen/nitrogen mixture were stabilized at atmospheric pressure

Because of very large separation introduced by this vertical flow reactor in the different reaction stages and of suitable working conditions, several hydrocarbons—like vinylacetylene, benzene, toluene, xylenes, styrene, ethynylbenzene and methylnaphthalene—have been found in the blue and yellow flames by means of GC—MS

These hydrocarbons can be regarded as intermediate products in the formation of p.c.a.h. according to Badger's study in his pyrolysis experiments of several organic compound

Finally with this type of reactor it was possible to start the study of the deposition process of the polycyclic aromatic hydrocarbons and particularly of the potent carcinogens, like benz(a) anthracene and benz(a) pyrene by examining in which reactor zones, characterized by a given temperature range and by a particular soot morphology, they were collected

It is our opinion that the physical and chemical considerations presented by this study can become very useful since much effort will have to be devoted in future to the problem of freeing the exhaust gases from polycyclic aromatic hydrocarbons.