Mechanisms of soot thermal decomposition: Reactive molecular dynamics study

Understanding the mechanisms of soot formation and decomposition is important for reduction of harm-ful emissions from combustion. Soot sublimation temperature varies in a wide range from approximately 250 0 to 450 0 K and the fundamental reasons for such drastic discrepancy are still unknown. To shed light on the relationship between soot morphology and its sublimation temperature and to study the molecular products of its sublimation we model thermal decomposition of soot using reactive molecu-lar dynamics simulations. Our results show that besides well-known low-molecular-weight C1 -C5 species soot can also decompose into graphene-like products with mass up to 30 0-60 0 Da. Mass distribution of the sublimation products strongly depends on the morphology of the particle which in turn depends on the conditions at which the particle was formed. Moreover we demonstrate that those soot particles which can withstand temperatures up to 30 0 0 K undergo fast annealing and sintering which additionally enhances their thermal stability.(c) 2022 The Combustion Institute. Published by Elsevier Inc. All rights reserved.