Insights on the Effect of Ethanol on the Formation of Aromatics

EasyChair Preprint 815

Abstract

Polycyclic aromatic hydrocarbons (PAHs) and soot are generated by combustion processes, such as transportation, power generation, and waste incineration. Their escape from these processes into the atmosphere can cause both acute and long-term respiratory effects, and their deposition on soil and plants and in the surface water constitutes an important contamination of the human food chain. The addition of oxygenated compounds to hydrocarbon fuels have shown a reduction in PAHs, CO2, unburned hydrocarbons and soot. However, uncertainties still remain regarding the key reaction mechanisms responsible for these effects. In this paper, we report on the molecular mechanisms that contribute to the formation of polycyclic aromatic compounds in ethanol-doped ethylene flames, using a combination of deterministic and stochastic methods. Six ethylene/air premixed flame conditions with two equivalence ratios and two ethanol doping percentages were studied. Results show a reduction of acetylene, small aromatics, and large PAHs mole fractions when the percentage of added ethanol increases in ethylene flames. Stochastic modeling results then revealed the percentage of oxygenated species has a maximum of 45% at a HAB of 2 mm in all flames. Analysis of the formed oxygenated structures shows that most of them are phenols, around 15% are furans, and a small amount are ethers. In addition, results indicate a reduction in both chemical growth rate and cumulative chemical growth when increasing the ethanol doping percentage. This could further be accounted for the soot reduction with ethanol additions.

Keyphrases: Ethanol, Oxygenated compounds, PAH, Pollutants formation and control, Polycyclic aromatic hydrocarbons, Soot precursors

@booklet{EasyChair:815,
  author    = {Qi Wang and Angela Violi},
  title     = {Insights on the Effect of Ethanol on the Formation of Aromatics},
  doi       = {10.29007/59q8},
  howpublished = {EasyChair Preprint 815},
  year      = {EasyChair, 2019}}