Hydrodynamics, Oxygen Mass Transfer, and Sodium Methyl Mercaptan Oxidation in a Scaled-Up Airlift Loop Reactor

This study investigates the hydrodynamics, oxygen mass transfer, and sodium methyl mercaptan (NaSR) oxidation in a scaled-up airlift loop reactor, aiming to clarify the interplay between operational parameters and reaction efficiency. Computational Fluid Dynamics (CFD) simulations, coupled with the Euler–Euler approach, population balance model (PBM), Higbie’s penetration theory, and Arrhenius-type reaction kinetics, were employed. Experimental determination of reaction kinetics provided foundational data for model validation. Increasing superficial gas velocity Ug enhances kLa magnitude and spatial distribution uniformity, promotes bubble circulation between the riser and downcomer, and improves dissolved oxygen concentration. Numerical simulations showed good agreement with industrial data, confirming their reliability. Notably, at Ug = 0.0045 m/s, insufficient oxygen mass fraction in the downcomer was observed due to slow bubble renewal. The volumetric mass transfer coefficient exhibits larger value in downcomer due to the reasonable liquid turbulence dissipation. These findings provide critical insights for optimizing operational parameters in large-scale airlift reactors for NaSR oxidation.