In chapter 4, preliminary kinetic modeling of the PAH formation of toluene (+benzene) pyrolysis at one experimental condition (1467 K, 10.02 Torr, up to 0.56 s) is reported to describe major product peaks observed from Shukla et al86. using the reaction mechanism generator.37 Chapter 5 shows a recommended future application of the knowledge learned from this thesis to astrochemistry. Overall, the studies here show a successful investigation of bottom-up PAH formation through experimental and theoretical approaches.

Experimental and detailed chemical kinetic modeling has been performed to investigate aromatic and polyaromatic hydrocarbon formation pathways in a rich, sooting, ethylene-oxygen-argon premixed flame. An atmospheric pressure, laminar flat flame operated at an equivalence ratio of 2.5 was used to acquire experimental data for model validation. Gas composition analysis was conducted by an on-line gas chromatograph/mass spectrometer (GC/MS) technique. Measurements were made in the flame and post-flame zone for a number of low molecular weight species, aliphatics, aromatics and polycyclic aromatic hydrocarbons (PAHs) ranging from two to five-aromatic fused rings. The modeling results show the key reaction sequences leading to aromatic and polycyclic aromatic hydrocarbon growth involve the combination of resonantly stabilized radicals. In particular, propargyl and 1-methylallenyl combination reactions lead to benzene and methyl substituted benzene formation, while polycyclic aromatics are formed from cyclopentadienyl radicals and fused rings that have a shared C5 side structure. Naphthalene production through the reaction step of cyclopentadienyl self-combination and phenanthrene formation from indenyl and cyclopentadienyl combination were shown to be important in the flame modeling study. The removal of phenyl by O2 leading to cyclopentadienyl formation is expected to play a pivotal role in the PAH or soot precursor growth process under fuel-rich oxidation conditions.

Pyrolysis of Organic Molecules with Applications to Health and Environmental Issues, the 28th volume in the Techniques and Instrumentation in Analytical Chemistry series, gives a systematic and comprehensive description of pyrolysis of non-polymeric organic molecules. Pyrolysis is involved in many practical applications as well as in many common human activities, but harmful compounds can be generated in the process. The study of pyrolysis and of the formation of undesirable compounds as a result of pyrolytic processes is of considerable interest to chemists, chemical engineers, and toxicologists. - Pyrolysis results for compounds not previously studied or reported - Updated information from a large body of results published on pyrolysis of individual compounds or classes of compounds - Information on mechanisms and kinetics of numerous pyrolytic processes