Carbon particle formation and decay in two-step pyrolysis of carbon suboxide behind shock waves

Abstract

The formation and decay of carbon particles following the pyrolysis of C3O2 was investigated behind reflected shock waves toward high temperatures. It is known that in hydrocarbon pyrolysis the temperature range for soot formation extends from about 1300 to 2200 K. That holds also for C3O2. Here, it could be observed that particle formation starts again above 2300 K and increases toward a maximum at around 3000 K, falling off steeply above 3450 K. This maximum is nearly as high as that of the low-temperature particle yield curve at around 1600–1700 K. At temperatures above 3450 K, the process of particle disappearance behind the reflected shock wave was observed, which seems to depend on the history of their formation behind the incident shock wave.