Defence Lu Zhang: "Transport characterization and application of packed bed microreactors"
Promotors: 1st promotor: Prof Jun Yue, 2nd promotor: Prof Erik Heeres
Abstract: Packed bed microreactors (PBMs) represent a significant advancement in the development of green and sustainable chemical processes. This thesis aims to elucidate the hydrodynamic behavior and gas–liquid mass transfer characteristics of PBMs to support their application in heterogeneous catalytic reactions and promote process intensification.
First, a comprehensive review of the state-of-the-art applications of PBMs in chemical and fuel production, catalyst screening, and kinetic studies was presented. Representative reactions involving different reactant phases and catalyst types were discussed, along with current challenges, potential solutions, and future research perspectives.
Subsequently, single-phase N₂ or water flow in PBMs packed with spherical glass beads was investigated, with particular emphasis on pressure drop behavior over a wide microreactor-to-particle diameter ratio (D/d = 1.29–25.12). In parallel, gas–liquid hydrodynamics and mass transfer properties in single pellet string microreactors (SPSMs, 1 < D/d < 1.866) were examined using a non-reactive N₂–water system and a reactive CO₂– alkaline solution system. The gas–liquid two-phase flow regimes and corresponding flow maps were established. Two-phase pressure drop and mass transfer coefficients were analyzed using existing correlations and further refined by incorporating bed structural properties.
Finally, the application of PBMs to methylene blue photocatalytic degradation over g-C₃N₄ was demonstrated, highlighting the significant potential of PBMs for operating condition optimization and reaction mechanism analysis.