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Samuel Marre
CNRS Researcher
                                                                                                                                                                                                                                                                                          
Supercritical Fluids Group (group VII)
Institut de Chimie de la Matière Condensée de Bordeaux
(ICMCB)
87 Avenue du docteur Albert Schweitzer
33608 PESSAC Cedex

Phone: +0033 6 79 87 88 25
samuel.marre@icmcb.cnrs.fr





Research interests
  • Supercritical Microfluidics ("Microfluidique Supercritique"): High pressure / High temperature microsystems for applications involving Supercritical Fluids
  • Geological Labs on Chip / CO2 geological storage
  • Biogeolocial labs on chip for investigating CO2 bioconversion in geological media
  • Multifunctional micro and nanomaterials synthesis and processing
  • Chemical Engineering
  • Chemistry in Supercritical Fluids
  • Photochemistry processes
  • Thermo-Hydrodynamics effects

Research news

Studying key processes related to CO2 underground storage at the pore scale using high pressure micromodels

React. Chem. eng., 2020, advance article. Link

In this review, we present a general overview of the current progress in pore scale experimentations related to CO2 geological storage. In such processes occurring in porous media, most of the phenomena start from (bio)geochemical reactions and transport mechanisms at the pore scale. Therefore, in order to predict the overall consequences of CO2 injection inside a deep reservoir and to ensure a safe installation, it is essential to access pore-scale information for geochemical numerical methods and to improve the understanding of the critical operating parameters. In this view, high pressure micromodels that mimic geological media (Geological Labs on Chip) have recently attracted interest to study multiphase flows and chemical reactivity in porous media. Emphasis is placed on experiments that can be performed in realistic pressure conditions representative of deep geological formations, for accessing information on reactive flows in porous media, mineralization/dissolution, but also (bio)chemical processes. The use of such micromodels continues to broaden the investigation space thanks to the design of in situ characterization techniques. Together high-fidelity data not easily accessed in conventional batch or core-scale procedures is made readily available.

Process Intensification for the synthesis of ultra-small organic nanoparticles with supercritical CO2 in a microfluidic system


Chem. Eng. Journal, 2020, 397, 125333. Link

Submicronization of organic compounds is a challenging requirement for applications in the imaging and pharmaceutical fields. A new Supercritical AntiSolvent process with microreactor (µSAS) was developed for nanoparticle (NP) synthesis. Tetrahydrofuran (THF) was used to solubilize a model organic molecule, tetraphenylethylene, and supercritical carbon dioxide (sc-CO2) was used as antisolvent. The solubility of TPE in the THF/CO2 system was first measured by in situ experiments. Then, NPs of TPE were prepared in various experimental conditions and characterized by transmission electron microscopy (TEM). Chosen experimental conditions led to NPs with a mean size of 9 ± 3 nm. Experimental µSAS results were compared with size distributions obtained by simulation, to obtain surface tension values, which are difficult to access by experiment alone. Simulations coupling Computational Fluid Dynamics (CFD) and Population Balance Equation (PBE) were performed under turbulent conditions in the high pressure microreactors. This coupled experimental and theoretical approach allowed a deep understanding of the µSAS process and underlined the superior value of this technique for the preparation of NPs.

Mixing intensification under turbulent conditions in a High pressure microreactor


Chem. Eng. Journal, 2020, 382, 122859. Link

The turbulent mixing of two miscible fluids is investigated in a high pressure (HP) coflow microreactor operated at 100 bar. Ethanol and CO2 are selected as model solvents to mimic the final targeted application, i.e.: a supercritical antisolvent process at microscale (SAS). We first demonstrate experimentally that turbulent mixing can be reached in a microchannel using HP microfluidics. A computational fluid dynamic (CFD) model, performed using direct numerical simulation (DNS) down to the Kolmogorov scale has been applied for the turbulent mixing simulations. The effects of the main operating parameters on the final mixing efficiency have been studied, namely: the temperature, the fluid flowrates, the microchannel dimensions and the capillary inner and outer diameters. According to a predefined intensity of segregation, the characteristic mixing times are determined and used for determining mixing efficiency. The ratio of the total mixing time to the diffusion time depends on the ratio of the kinetic energies (the outer fluid to the inner one). The obtained micromixing times have been related to the turbulent energy dissipation rate , calculated directly from the velocity fluctuations. The mixing intensification is obtained with much lower characteristic mixing times in the microreactor (one order of magnitude) than previously reported. This fundamental study is an indispensable guidance for several processes, including the SAS applications.

Investigating Laminar mixing in High pressure microfluidic systems

 

Chem. Eng. Sci., 2019, 205, 25-35. Link

In this study, the hydrodynamic behavior of coflowing fluids CO2 and ethanol has been investigated in a high-pressure microfluidic reactor working at supercritical conditions, in which the two fluids are completely miscible. The velocity field has been measured by Micro Particle Image Velocimetry (PIV) for different temperatures between 20 and 50 °C at a fixed pressure of 100 bar. Meanwhile, we have developed a model to investigate numerically the mixing. By comparing the experimental results to a three-dimensional numerical simulation, the mixing model has been validated for the laminar coflow in the micromixer. In order to understand the mixing condition effects, several parameters have been investigated, namely: the Reynolds number, the temperature and the CO2/ethanol ratio. A mixing time constant is defined by using the segregation intensity curve and later used to characterize the mixing quality. The characteristic mixing time has been related to the laminar energy dissipation rate , similarly to the stretching efficiency model in previous studies. The mixing quality is eventually analyzed in term of segregation index and mixing time.


Collaborations / contacts

Dr. Timothy Noël, TU/Eindhoven, The Netherlands
Dr. Karyn Rogers, Renssaeler Polytechnic Institute, Troy, NY, USA.
Dr. Simon Kuhn, KU Leuven, Belgium
Dr. Yves Garrabos, Supercritical fluid group at ICMCB-CNRS, Bordeaux, France.
Dr. Virginie Nazabal, Equipe verres et céramiques, ISCR, Rennes, France.
Pr. Ryan L. Hartman, New York University, NY, USA.
Pr. Mike T. Timko, Worcester Polytechnic Institute, Worcester, MA, USA.
Dr. Mathieu Pucheault, Institut des Sciences Moléculaires (ISM), Bordeaux, France.