PARBUIN - Particle-Bubble Interactions for Green Processes

Bubble columns are widely used in the chemical, petrochemical, biochemical and metallurgical industries. They are used for oxidation, chlorination, alkylation, polymerization and hydrogenation. Three-phase bubbling flows are the focus today, as the reactors are an essential component for converting CO2 into reusable methane or methanol. The gas/solid (catalyst)/fluid interaction brings uncertainties in reactor design, optimization and control. A better understanding will enable resource-efficient reactor design and control. Slurry bubble column (SBC) reactors consist of liquid columns tens of meters high in which dispersed bubbles and solid particles (size scales: millimeters and micrometers, respectively) interact, which in turn determine the global multiphase flow properties. The wide range of length scales requires high-resolution techniques for both metrological and simulation-based studies. Current literature refers to two-phase bubble columns to represent global hydrodynamics on a coarse scale. Some of the applied models and correlations contain unresolved physical relationships for three-phase flows. We develop a coupled liquid-volume immersed boundary method that enables fully resolved simulation of interfacial structures (droplets and/or bubbles) interacting with moving small particles, for accurate information on the physics of liquid-gas-solid flow, and propose new subgrid models and physical correlations for macroscopically oriented CFD simulations. Complementary particle tracking and TomoPIV measurements will be performed in countercurrent columns at various scales to validate the simulations and provide new insights into the small-scale hydrodynamic phenomena in SBCs.