The formation of aromatics from the gas-phase pyrolysis of stigmasterol: kinetics

The gas-phase pyrolysis of stigmasterol was investigated using molecular beam mass spectrometry to study the reaction pathways that lead to the formation of aromatic compounds and to build an empirical kinetic model. We used multivariate data analysis to extract trends in the data and identify major product classes. Based on this analysis, we have developed a lumped kinetic model to describe the formation of intermediates and polynuclear aromatic hydrocarbons (PAHs). In our reaction scheme, stigmasterol is converted to highly substituted aliphatic ring compounds. These intermediate compounds are then converted to PAHs. We determined kinetic parameters for the two step process and used them to produce response surface plots for the two product classes as a function of temperature and gas-phase residence time.