2024 AIChE Annual Meeting
(110c) A Shock Tube Laser Schlieren Study of Perfluorobutyric Acid (PFBA) Pyrolysis
Authors
Rocchio, C., Brown University
Kim, K., Argonne National Laboratory
Tranter, R. S., Chemistry Division, Argonne National Laboratory
Goldsmith, C. F., Brown University
The pyrolysis of perfluorobutyric acid (PFBA, C4HF7O2) was investigated using laser schlieren densitometry (LS) in the diaphragmless shock tube. Experiments were performed with mixtures of 1%, 2%, and 4% PFBA in excess argon at 30, 60, 120, and 240 torr between 1400 and 2200 K. The experimental density gradients from the LS method were simulated using the Frhodo software with a detailed kinetic mechanism developed from high-level theoretical calculations. The experiments agreed with the kinetic mechanism when the initial dissociation channels were scaled down by a factor of 10. The initial dissociation pathways included carbon-carbon scission, HF-elimination, and defluorination channels. Secondary chemistry involved disproportionation reactions and F-abstractions via trifluoromethyl radical (CF3) to yield a mixture of carbon tetrafluoride (CF4), smaller perfluorocarboxylic acids, perfluoroalkenes, and other species. The model captures pressure and temperature dependences such that the reaction rates were extrapolated to incinerator-relevant conditions.