Nicolas DietrichChemical Engineering

2016 : Optical Methods to Investigate the Enhancement Factor of an 2 Oxygen-Sensitive Colorimetric Reaction Using Microreactors

Visualization of mass transfer is a powerful tool to improve understanding of local phenomenon. The use of an oxygen-sensitive dye (colorimetric technique) (Dietrich et al., Chem Eng Sci. 2013; 100:172–182) has showed its relevancy for locally visualizing and characterizing gas–liquid mass transfer at different scales (Kherbeche et al., Chem Eng Sci. 2013; 100: 515–528; Yang et al., […]

Nicolas DietrichChemical Engineering

2015 : FAST MEASUREMENTS OF GAS-LIQUID DIFFUSION COEFFICIENT IN THE GAUSSIAN WAKE OF A SPHERICAL BUBBLE

    By : N. DIETRICH, J. FRANCOIS, M. JIMENEZ, A. COCKX, P. GUIRAUD, G. HEBRARD  Abstract: A fast method is proposed for determining the oxygen gas-liquid diffusion coefficient from measurements of the fluorescence quenching behind a bubble. The approach consists of capturing pictures of concentration field at micro-scale in the laminar bubble wake. The […]

Nicolas DietrichChemical Engineering

2014: Oxygen mass transfer and hydrodynamic behaviour in wastewater: Determination of local impact of surfactants by visualization techniques

By Mélanie Jimenez, Nicolas Dietrich, John R. Grace, Gilles Hébrard Abstract: Powerful techniques, based on the Planar Laser Induced Fluorescence (PLIF) technique, are deployed to locally visualize and quantify the impact of surfactants in wastewaters on hydrodynamics and oxygen mass transfer. Bubble diameter, aspect ratio, rise velocity, contamination angle, as well as flux, flux density, […]

Nicolas DietrichChemical Engineering

Mass transfer in the wake of non-spherical air bubbles quantified by quenching of fluorescence

 M. Jimenez, N. Dietrich, G. Hébrard, Chem. Eng. Sci. (2013)   Full paper here Abstract Based on planar laser induced fluorescence with inhibition (PLIFI) experiments, the mass transfer behavior in the wake of single rising air bubbles is investigated. Bubbles of equivalent diameters ranging from 0.90 to 2.24 mm are studied, exhibiting vertical and zigzagging paths […]