The study on formation process of PAHs under different combustion conditions

摘要

N-heptane was used as an alternative fuel to simulate diesel. Established and validated “C.M mechanism” which contains detailed elementary reactions of formation and oxidation of PAHs. Analyzed the formation process of PAHs under different combustion conditions by using shock tube and premixed flame model. The results showed that “C.M mechanism” can predict the concentration and trends of aromatic substances in the process of combustion. Benzene was mainly produced through the polymerization reaction of C3H3. Naphthalene was formed by HACA of benzene and C4H4 combination reaction. Finally, cyclization reaction between benzenes formed PAHs. The formation process of naphthalene and pyrene were similar under different combustion conditions. There were several formation processes of phenanthrene under premixed flame model, while under the shock tube; phenanthrene was mainly produced through the addition reaction of biphenyl and acetylene.