TY - JOUR
T1 - Investigation of interfacial mass transfer phenomena applying non-invasive Raman imaging and density gradient theory
AU - Deuerling, J.
AU - Alsalih, A.
AU - Nagl, R.
AU - Zeiner, T.
AU - Repke, J. U.
AU - Rädle, M.
N1 - Publisher Copyright:
© 2024 The Authors
PY - 2024/4/5
Y1 - 2024/4/5
N2 - This study presents a novel non-invasive Raman measurement setup for investigating diffusion and mass transfer processes at liquid/liquid interfaces, based on a photometric setup utilizing customized photon multiplier (CPMs). The results highlight the effectiveness, reliability and applicability of this setup in visualizing and analyzing acetone mass transfer across the aqueous-organic interface. The study focuses on the liquid/liquid extraction of acetone from the aqueous phase into the organic phase, using toluene as the organic solvent. The study's key findings indicate that – in the absence of forced convection – mass transfer across the interface is not the limiting factor in the extraction process; instead, diffusion in the bulk phase takes precedence. Acetone's rapid local transport from the aqueous to the organic phase is observed, with a temporary concentration minimum on the aqueous side of the interface. In the organic phase, local equilibrium is reached near the interface first, only after which acetone disperses into the bulk phase. This dual mechanism—fast interfacial mass transfer and slower bulk-phase diffusion—marks a significant feature of the considered extraction process, which were further substantiated by dynamic concentration gradient theory simulations. The research further demonstrates the feasibility of upscaling interfacial mass transfer simulations using adaptive meshing. However, macroscopic effects like induced convection challenge purely diffusive models. The simulations confirm rapid enrichment of acetone at the interface, followed by slower mass transfer through the interface and bulk phase diffusion, consistent with the experimental data. Experimental and modeled results align well with literature data for liquid/liquid extraction, thereby validating the accuracy of the presented novel diffusion measurement setup and demonstrating its potential to investigate mass transfer phenomena near liquid/liquid interfaces.
AB - This study presents a novel non-invasive Raman measurement setup for investigating diffusion and mass transfer processes at liquid/liquid interfaces, based on a photometric setup utilizing customized photon multiplier (CPMs). The results highlight the effectiveness, reliability and applicability of this setup in visualizing and analyzing acetone mass transfer across the aqueous-organic interface. The study focuses on the liquid/liquid extraction of acetone from the aqueous phase into the organic phase, using toluene as the organic solvent. The study's key findings indicate that – in the absence of forced convection – mass transfer across the interface is not the limiting factor in the extraction process; instead, diffusion in the bulk phase takes precedence. Acetone's rapid local transport from the aqueous to the organic phase is observed, with a temporary concentration minimum on the aqueous side of the interface. In the organic phase, local equilibrium is reached near the interface first, only after which acetone disperses into the bulk phase. This dual mechanism—fast interfacial mass transfer and slower bulk-phase diffusion—marks a significant feature of the considered extraction process, which were further substantiated by dynamic concentration gradient theory simulations. The research further demonstrates the feasibility of upscaling interfacial mass transfer simulations using adaptive meshing. However, macroscopic effects like induced convection challenge purely diffusive models. The simulations confirm rapid enrichment of acetone at the interface, followed by slower mass transfer through the interface and bulk phase diffusion, consistent with the experimental data. Experimental and modeled results align well with literature data for liquid/liquid extraction, thereby validating the accuracy of the presented novel diffusion measurement setup and demonstrating its potential to investigate mass transfer phenomena near liquid/liquid interfaces.
KW - Concentration Gradient Theory
KW - Interfacial Mass Transfer
KW - Liquid/liquid extraction
KW - Local concentration measurement
KW - Optical measurements
KW - Raman photometry (spectro-photometry)
UR - http://www.scopus.com/inward/record.url?scp=85182268721&partnerID=8YFLogxK
U2 - 10.1016/j.ces.2023.119672
DO - 10.1016/j.ces.2023.119672
M3 - Article
AN - SCOPUS:85182268721
SN - 0009-2509
VL - 287
JO - Chemical Engineering Science
JF - Chemical Engineering Science
M1 - 119672
ER -