The effect of reaction mechanisms on the formation of soot precursors in flames

Abstract

Nanoparticles formed in gas-phase combustion environments are ubiquitous in modern society as hazardous pollutants. Due to the deleterious health effects of carbonaceous nanoparticles it is important to gain a better understanding of the fundamental processes that lead to their formation and growth. We have utilised our Stochastic NAnoParticle Simulator software to model the growth of soot precursor species in a laminar premixed benzene–air flame. We implemented a new set of pathways containing oxygenation reactions and assessed the effects on the growth mechanisms. The inclusion of oxygenation growth pathways with the previously established hydrocarbon growth pathways creates a much larger set of potential configurations for the particle to explore and thus the rate of growth is faster. Hydrogen abstractions and acetylene additions are still the most common events the particle experiences during its evolution trajectory; however, a significant amount of ethers and oxygen-containing rings are formed. Though the role of soot precursor oxygenation is not completely solved, it certainly adds layers of complexity to the nanoparticles’ formation process and likely influences the formation of soot particles.