A Detailed Chemical Kinetic Model for the Thermal Destruction of Perfluorobutanesulfonic Acid

Abstract Perfluorobutanesulfonic acid (PFBS), a member of the per- and polyfluoroalkyl substances (PFAS) family, poses significant environmental and health risks due to its persistence and resistance to degradation. Understanding its thermal decomposition pathways is critical for effective incineration-based remediation. In this study, a detailed chemical kinetic mechanism is presented for the thermal destruction of PFBS, and this mechanism is used in a simulation of an incinerator. The results reveal that unimolecular bond fission leading to C3F7CF2 + SO3H is the dominant decomposition pathway across a wide temperature range (400–2000 K), with negligible contribution from alternative channels. Subsequent chemistry is governed by the reactivity of C3F7CF2 radicals. Reactor simulations further demonstrate that the presence of OH radicals promotes the formation of perfluoroaldehydes. These findings indicate that PFBS incineration is initiated by C–S homolysis rather than α-sultone formation, highlighting a fundamental mechanistic distinction between perfluorosulfonic and perfluorocarboxylic acids. This work provides critical insights for designing efficient thermal destruction strategies for PFAS.