Hydrodynamics and mass transfer studies on plate-type microchannel reactor for liquid–liquid systems

Abstract

This work reports hydrodynamic and mass transfer studies on a novel microreactor that can passively break up liquid–liquid slugs using judiciously placed internals. The reactors were fabricated in stainless steel (SS-316 L, hereafter SS) and PMMA (hereafter acrylic). The performance of both is comparable to the current state-of-the-art in microreactor technologies. A separated flow model is proposed to estimate the pressure drop for two-phase flows, with a mean absolute error (MAE) of 15.44% in SS and 19.83% in acrylic, respectively. Pulse tracer experiments were performed for residence time distribution (RTD) studies. They are fitted to a model for the prediction of RTD for single and two-phase flows. The results obtained from mass transfer experiments show that the volumetric mass transfer coefficient ($k_{L}a$) in the case of SS reactor is, on average, 2.4 times higher than acrylic. A correlation is developed for estimating the $k_{L}a$ based on total velocity and phase fraction, providing better fits than the models based on energy dissipation. All studies show that wall characteristics significantly impact the hydrodynamics and mass transfer phenomena since the pressure drop and the $k_{L}a$ are greater in (the rougher) SS than in acrylic.