Structure of carbonaceous nanoparticles formed in various pyrolysis systems

Abstract In the pyrolysis of different hydrocarbon/carbon suboxid-fuels formation of carbon particles with the special view to their structures were investigated. For this, the following three very different pyrolysis systems were investigated experimentally i) a pyrolysis reactor, ii) a shock-tube and iii) a plasma reactor with respect to the influence of varying reaction parameters on the carbonaceous nanoparticles. The particles formed in these reaction systems were studied in view of their morphology and state of crystallization by use of electron microscopy (Philips CM30) at low- and high resolution combined with micro-diffraction measurements. As to be seen at low resolution of the transmission electron microscopy studies, the particle sizes in the pyrolysis reactor and shock-tube do not differ significantly, but distinguished considerably from those particle sizes obtained in the plasma reactor. While the particles obtained in the pyrolysis reactor and shock-tube had particle diameters of about d ≈ 30 nm, the particles in the plasma reactor consisted of fluffy-like units, and their sizes were about d ≈ 4 nm. The various carbon layers consisted of different polyaromatic hydrocarbon units with variable sizes arranged to diverse states in the course of graphitization.