Two-phase liquid flows in small channels for intensified separations

Abstract: Flows of two immiscible liquids in small channels significantly enhance mass transfer. These improvements are closely linked to the two-phase hydrodynamics and the available interfacial area. Among the patterns forming in small channels, plug and dispersed flows provide large interfacial areas, making them particularly suitable for mass transfer operations. Understanding and being able to predict the flow patterns which establish under different flow conditions and channel characteristics is, therefore, important for the advancement of intensified two phase contactors.

In the presentation I will discuss the liquid-liquid flow patterns and their hydrodynamic characteristics for two types of intensified contactors, T-junction small channels, and confined impinging jets. Experiments have been combined with computational fluid dynamics simulations to characterise the break up of the phases at the contactor inlets and the flow fields and mixing in the main channels. Indicative results will be presented from the application of the contactors to critical metals recovery using solvent extraction separations. Critical metals are central to the transition to a net zero, information based economy and their recovery from waste mixtures is thus crucial. The results demonstrate the significant influence of the flow phenomena on mass transfer intensification.

Bio: Prof Panagiota Angeli, FREng, FIChemE, is a Professor in the Department of Chemical Engineering at UCL, and leads the ThAMeS Multiphase group. She obtained a Diploma in Chemical Engineering from the National Technical University of Athens and a PhD on Multiphase Flows at Imperial College London. She specializes on complex multiphase flows particularly those involving two liquid phases and their application to intensified processing. Her research aims to link small scale interactions and interfacial phenomena to the macroscopic behaviour of the complex flows and to the development of predictive models. She has been investigating the effects of surfactants, particles and non-Newtonian rheologies on two-phase microchannel flows, as well as their applications to the analysis and intensification of metal separations, and to the manufacturing of complex formulations. The experimental investigations have been enabled by original and advanced sensing and measurement techniques, such as micro- and high speed Particle Image Velocimetry (PIV) and ultrasound. Prof Angeli’s work has been supported by substantial UK Research Council and European Union funding and by industry. She has been awarded a RAEng/Leverhulme Trust Fellowship and has participated and chaired UK EPSRC and international (Norway, Sweden, Ireland, Belgium) research funding review panels. She is associate editor of IJMF has delivered many plenary/keynote lectures and has published over 220 journal papers.