The influence of temperature on the formation of soot from ethylene pyrolysis has been studied. Pyrolysis experiments were carried out in a quartz reactor in the 1000-1200 °C temperature range, for an inlet C2H4 concentration of 50000 ppmv and a gas residence time of 4552/T(K) seconds. Outlet gases were analyzed by gas chromatography and the amount of soot produced measured. The reactivity of the soot samples obtained towards O2 and NO was also studied. Results show that the higher the formation temperature, the less reactive the soot. The soot samples were further characterized using elemental analysis, scanning electron microscopy and Raman spectroscopy, in order to study their structural properties, and relate them to their reactivity. Additionally, a comparison of the reactivity towards NO between acetylene and ethylene soot samples obtained under similar conditions has been carried out. The soot samples obtained from ethylene pyrolysis present higher reactivity towards NO than the soot samples formed from acetylene.
©2011 Walter de Gruyter GmbH & Co. KG, Berlin/Boston