(171aa) Coupled Level-Set Volume of Fluid (CLS-VOF) Computational Fluid Dynamics of a Molten-Tin Bubble Column Reactor for Sulfur Hexafluoride (SF6) Degradation

Molten-metal bubble column reactors (MMBCRs) have been used in diverse processes, such as the pyrolysis of hydrocarbons for producing clean hydrogen and recoverable carbon, as well as the treatment of waste fluorinated-gases released from the semiconductor industry. Optimal design of an MMBCR requires an understanding of hydrodynamics, bubble characteristics at each flow regimes, heat and mass transfer, and chemical reaction kinetics. This study proposes a coupled level-set volume-of-fluid (CLS-VOF) computational fluid dynamics (CFD) model for degrading sulfur hexafluoride (SF₆) in a 0.3 m tall MMBCR with molten tin (Sn) at 618 °C and an inlet flow rate of 1 L/min. An algorithm for estimating the interfacial surface area of individual bubble domains was introduced for the Cartesian mesh. Compared to the conventional VOF model, the CLS-VOF model more accurately predicted the surface curvature and its normal vector. This approach facilitated the calculation of hydrodynamics and reaction kinetics within MMBCRs for the SF₆ degradation process.