Catégorie : Chemical Engineering

Nicolas DietrichChemical Engineering

2025: Modeling oxygen mass transfer in surfactant solutions considering hydrodynamics and physico-chemical phenomena

Abstract The present study offers a predictive correlation for oxygen transfer based on the exhaustive analysis of more than 300 isolated gas bubbles and the examination of interfacial colonization phenomena occurring in the presence of surfactants. The correlation is formulated by accounting for two key aspects: the hydrodynamic influence exerted by surfactants on mass transfer […]

Nicolas DietrichChemical Engineering

2023: Impact of surfactants on the rise of deformable bubbles and interfacial gas–liquid mass transfer

Abstract Axisymmetric numerical simulations of the hydrodynamics around rising bubbles are performed in order to investigate the impact of surfactants on the bubble dynamics. Surfactants are assumed to be insoluble. The transport of the adsorbed surfactants is computed along the deforming surface at large surface Péclet number, and Marangoni stresses are taken into account. This […]

Nicolas DietrichChemical Engineering

2023: Innovative High-Pressure Water Scrubber for biogas upgrading at farm-scale using vacuum for water regeneration

Abstract Biogas upgrading is becoming essential in the valorization path for biogas. Biomethane from anaerobic digestion is identified to be one of the main resources to decarbonize the energy requirement. However, small-scale (especially farm-scale) applications suffer from a lack of implementation worldwide, mainly limited by the cost of the upgrading process. As one of the most used technologies, High Pressure […]

Nicolas DietrichChemical Engineering

2022: Direct numerical simulation of gas-liquid mass transfer around a spherical contaminated bubble in the stagnant-cap regime

Abstract Direct Numerical Simulations are performed to investigate the gas-liquid mass transfer around a rising spherical bubble contaminated by insoluble surfactants. The surfactant transport on the bubble surface and the Marangoni effect are taken into account when solving the hydrodynamics, resulting in the stagnant-cap condition. A parametric study is carried out to investigate the mass transfer by varying the Reynolds, […]

Nicolas DietrichChemical Engineering

2022: Experimental Solid–Liquid Mass Transfer around Free-Moving Particles in an Air-Lift Membrane Bioreactor with Optical Techniques

Abstract This article focuses on the study of the mass transfer involved in the application of a bacterial antifouling technique for membrane bioreactors (MBR), via the addition of solid media. These alginate objects can contain a biological system capable of producing an enzyme that degrades the signal molecules responsible for membrane fouling. The objective of […]

Nicolas DietrichChemical Engineering

2022: Luminescent probe synthesis for oxygen visualization technique: Application to the effect of surfactant structure on oxygen mass transfer

Abstract Planar Laser Induced Fluorescence with Inhibition (PLIF-I) is a powerful technique for studying the local gas/liquid oxygen mass transfer from a single rising bubble. However, to track oxygen in the liquid phase, it is necessary to use an oxygen sensitive luminescent probe, which needs to be unreactive toward the liquid phase. This article presents […]

Nicolas DietrichChemical Engineering

2022: Effect of surfactant lengths on gas-liquid oxygen mass transfer from a single rising bubble

Abstract This work is an experimental investigation of the effect of the nature of surfactants on oxygen mass transfer. The study focuses on three cationic surfactants with different hydrophobic chain lengths, and four nonionic surfactants with different hydrophilic chain lengths. Equilibrium adsorption isotherms are calculated for each surfactant from experimental values of surface tension in […]

Nicolas DietrichChemical Engineering

2022: Gas-liquid mass transfer characterization in a thin shrinking film at an atomization nozzle

Abstract In this paper, a light absorption method is applied to estimate the thickness of an atomizing liquid film at microscale that exits a spraying nozzle. By using a dioxygen sensitive dye, called resazurin, it is also possible to determine the local profile of dioxygen concentration resulting from the gas-liquid transfer from air into the liquid film. […]

Nicolas DietrichChemical Engineering

2022: Taylor bubble formation and flowing in a straight millimetric channel with a cross-junction inlet geometry.

Part I: Bubble dynamics Abstract The investigations of bubble formation dynamics at a cross-junction in a straight milli-channel were reported. The bubble formation process could be divided into the filling and squeezing stages, and their frequencies were compared at various conditions. It was found that the filling and squeezing frequencies were controlled mainly by the […]