Methane Impurity Effect in the Acetylene Decomposition on Size and Morphology of the Appearing Soot Particles

Abstract

The paper studied the effect of acetylene or its methane mixture pressure at decomposition in the laboratory cylindrical reactor with spark ignition to obtain the acetylene soot. Size range of the formed particles and their surface morphology were determined by scanning and transmission electron microscopy. Specific surface area distributions over the pore radii and evaluation of the acetylene soot samples particle size were identified using the adsorption method of limited evaporation. All the experimental methods used confirmed significant decrease in the acetylene soot particle size at the increase in the acetylene initial pressure during its decomposition. Accordingly, the particles specific outer surface increased, but the microporous specific surface of the particles outer shell practically was not changing. Methane present in the mixture with acetylene in decomposition significantly increased the particles size and reduced both the specific outer surface and the microporous surface of the soot particles shell. It is shown that the proposed method for analyzing distributions of the acetylene soot specific surface area over the pore radii makes it possible to estimate with high accuracy particle sizes, total soot specific surface area and contribution of various factors forming this surface