The Effect of the Residence Time in the High Temperature Field on the Fullerene and PAH Formation Mechanism

Fullerenes were generated and observed in the combustion processes of hydrocarbon fuel under reduced pressure conditions however the fullerene formation mechanism from PAHs in fuel rich hydrocarbon flames under reduced pressure conditions has not been clarified yet. In the present study, the effects of the residence time in the high temperature reaction field were investigated experimentally and the effects of the residence time on the contents of fullerenes and PAHs were discussed. The experimental results showed that the contents of fullerenes as well as PAHs in the total soot collected from the flue gas decreased with the increase of the residence time in the range from 800 to 1500 degree Celsius. On the other hand, the contents of fullerenes in the total soot decreased with the increase of the residence time over 1500 degree Celsius because the total PAHs contents in the flue gas increased under the present experimental conditions. It is essential for the fullerene generation to realize the optimal residence time from 800 to 1500 degree Celsius as well as that over 1500 degree Celsius with an appropriate PAH partial pressure in the combustion process.