Gang Wang, Umberto d'Ortona, Pierrette Guichardon. Improved partially saturated method for the lattice Boltzmann pseudopotential multicomponent flows. Physical Review E , 2023, 107 (3), pp.035301. ⟨10.1103/PhysRevE.107.035301⟩. ⟨hal-04307425⟩ Plus de détails...
This paper extends the partially saturated method (PSM), used for curved or complex walls, to the lattice Boltzmann (LB) pseudopotential multicomponent (MC) model and adapts the wetting boundary condition to model the contact angle. The pseudopotential model is widely used for various complex flow simulations due to its simplicity. To simulate the wetting phenomenon within this model, the mesoscopic interaction force between the boundary fluid and solid nodes is used to mimic the microscopic adhesive force between the fluid and the solid wall, and the bounceback (BB) method is normally adopted to achieve the no-slip boundary condition. In this paper, the pseudopotential interaction forces are computed with eighth-order isotropy since fourth-order isotropy leads to the condensation of the dissolved component on curved walls. Due to the staircase approximation of curved walls in the BB method, the contact angle is sensitive to the shape of corners on curved walls. Furthermore, the staircase approximation makes the movement of the wetting droplet on curved walls not smooth. To solve this problem, the curved boundary method may be used, but due to the extrapolation process, most curved boundary conditions suffer from massive mass leakage when applied to the LB pseudopotential model. Through three test cases, it is found that the improved PSM scheme is mass conservative, that nearly identical static contact angles are observed on flat and curved walls under the same wetting condition, and that the movement of a wetting droplet on curved and inclined walls is smoother compared to the usual BB method. The present method is expected to be a promising tool for modeling flows in porous media and in microfluidic channels.
Gang Wang, Umberto d'Ortona, Pierrette Guichardon. Improved partially saturated method for the lattice Boltzmann pseudopotential multicomponent flows. Physical Review E , 2023, 107 (3), pp.035301. ⟨10.1103/PhysRevE.107.035301⟩. ⟨hal-04307425⟩
Jiupeng Du, Nelson Ibaseta, Pierrette Guichardon. Characterization of polyurea microcapsules synthesized with an isocyanate of low toxicity and eco-friendly esters via microfluidics: Shape, shell thickness, morphology and encapsulation efficiency. Chemical Engineering Research and Design, 2022, 182, pp.256-272. ⟨10.1016/j.cherd.2022.03.026⟩. ⟨hal-04063865⟩ Plus de détails...
There are some studies on the synthesis of polyurea microcapsules. However, there is hardly a case where both green solvents and non-toxic isocyanates are used, especially in microfluidics. In this work, an environmentally friendly chemical system of interfacial polymerization (isocyanate: HDB-LV; solvent: octyl salicylate or dibutyl adipate) is tested for the first time to produce polyurea microcapsules. The size of microcapsules is calibrated at 78 μm by microfluidics to quantitatively analyze the relationships among shell thickness, encapsulation efficiency and isocyanate concentrations. The influences of solvent types and reactant concentrations on the shape, morphology and shell thickness of microcapsules are studied. Esters with low water miscibility and low amine concentrations (lower reaction rate) are crucial for the formation of spherical microcapsules. An ester with high water miscibility can diffuse into the continuous phase during encapsulation, which results in broken microcapsules. A high concentration of amine can probably cause cross-linking not only at the interface but also inside the droplet template, which leads to microcapsule deformation. A linear relationship is observed between the shell thickness of microcapsules and the isocyanate concentration. Overall, a high encapsulation efficiency (more than 90%) for octyl salicylate is achieved with polyurea microcapsules.
Jiupeng Du, Nelson Ibaseta, Pierrette Guichardon. Characterization of polyurea microcapsules synthesized with an isocyanate of low toxicity and eco-friendly esters via microfluidics: Shape, shell thickness, morphology and encapsulation efficiency. Chemical Engineering Research and Design, 2022, 182, pp.256-272. ⟨10.1016/j.cherd.2022.03.026⟩. ⟨hal-04063865⟩
Pierrette Guichardon, Carlos Baqueiro, Nelson Ibaseta. Villermaux–Dushman Test of Micromixing Characterization Revisited: Kinetic Effects of Acid Choice and Ionic Strength. Industrial and engineering chemistry research, 2021, 60 (50), pp.18268-18282. ⟨10.1021/acs.iecr.1c03208⟩. ⟨hal-03597451⟩ Plus de détails...
The well-known Villermaux-Dushman system is nowadays widely used for examining the micromixing efficiency either in batch or continuous intensified reactors. However, a bibliographic review shows that kinetic data are too scattered for a reliable determination of the micromixing times. The Dushman reaction kinetics is then reexamined with the use of sulfuric and perchloric acids. The results confirm the fifth-order rate law. More precisely, the I-, H+, and IO3- dependence orders on the rate law are, respectively, 2, 2, and 1, under any condition. To be more consistent with the reactant concentrations used in the Villermaux-Dushman test, we extend their studied range, namely, 1.6 x 10(-3) M <= [I-](0) <= 1.6 x 10(-2) M, 1.2 x 10(-4) M <= [H+](0) <= 1.57 x 10(-2) M, and 4 x 10(-5) M <= [IO3-] <= 2.1 X 10(-4) M. The ionic strength varies up to 2 M. The experimental results show that the rate constant is still ionic-strength-dependent. The results obtained with sulfuric and perchloric acids are found to be consistent and in relatively good agreement at small ionic strengths (mu < 0.1 M) only. At a higher ionic strength, the use of sulfuric acid requires sustained attention to the constant of the second dissociation equilibrium. The nonideal solution behavior raising at a high ionic strength makes its estimation deeply sensitive.
Pierrette Guichardon, Carlos Baqueiro, Nelson Ibaseta. Villermaux–Dushman Test of Micromixing Characterization Revisited: Kinetic Effects of Acid Choice and Ionic Strength. Industrial and engineering chemistry research, 2021, 60 (50), pp.18268-18282. ⟨10.1021/acs.iecr.1c03208⟩. ⟨hal-03597451⟩
Journal: Industrial and engineering chemistry research
Pierrette Guichardon, Carlos Baqueiro, Nelson Ibaseta. Villermaux–Dushman Test of Micromixing Characterization Revisited: Kinetic Effects of Acid Choice and Ionic Strength. Industrial and engineering chemistry research, 2021, 60 (50), pp.18268-18282. ⟨10.1021/acs.iecr.1c03208⟩. ⟨hal-03514628⟩ Plus de détails...
The well-known Villermaux-Dushman system is nowadays widely used for examining the micromixing efficiency either in batch or continuous intensified reactors. However, a bibliographic review shows that kinetic data are too scattered for a reliable determination of the micromixing times. The Dushman reaction kinetics is then reexamined with the use of sulfuric and perchloric acids. The results confirm the fifth-order rate law. More precisely, the I-, H+, and IO3- dependence orders on the rate law are, respectively, 2, 2, and 1, under any condition. To be more consistent with the reactant concentrations used in the Villermaux-Dushman test, we extend their studied range, namely, 1.6 x 10(-3) M <= [I-](0) <= 1.6 x 10(-2) M, 1.2 x 10(-4) M <= [H+](0) <= 1.57 x 10(-2) M, and 4 x 10(-5) M <= [IO3-] <= 2.1 X 10(-4) M. The ionic strength varies up to 2 M. The experimental results show that the rate constant is still ionic-strength-dependent. The results obtained with sulfuric and perchloric acids are found to be consistent and in relatively good agreement at small ionic strengths (mu < 0.1 M) only. At a higher ionic strength, the use of sulfuric acid requires sustained attention to the constant of the second dissociation equilibrium. The nonideal solution behavior raising at a high ionic strength makes its estimation deeply sensitive.
Pierrette Guichardon, Carlos Baqueiro, Nelson Ibaseta. Villermaux–Dushman Test of Micromixing Characterization Revisited: Kinetic Effects of Acid Choice and Ionic Strength. Industrial and engineering chemistry research, 2021, 60 (50), pp.18268-18282. ⟨10.1021/acs.iecr.1c03208⟩. ⟨hal-03514628⟩
Journal: Industrial and engineering chemistry research
Oleksandr Dimitrov, Pierrette Guichardon, Isabelle Raspo, Evelyne Neau. Vapor–Liquid Equilibria of the Aqueous and Organic Mixtures Composed of Dipropylene Glycol Methyl Ether, Dipropylene Glycol n -Butyl Ether, and Propylene Glycol n -Butyl Ether. Part II: Modeling Based on the NRTL-PR Model. Industrial and engineering chemistry research, 2021, 60 (30), pp.11513-11524. ⟨10.1021/acs.iecr.1c01545⟩. ⟨hal-03379757⟩ Plus de détails...
Further to the Part I of the present paper, the second Part is concentrated around the VLE modeling of binary mixtures involving the three glycol ethers previously studied experimentally. The authors propose to use the NRTL-PR model for the representation of these non-ideal mixtures. The main difficulties of modelling related to very low vapor pressures and the way of dealing with them are highlighted. The unknown critical parameters for DPM, DPnB and PnB were determined using robust group contribution methods. However, the experimental values of these parameters have never been published before. The main goal of the authors was to obtain the most satisfactory representation of the experimental data provided in the Part I. Some issues that mostly occurred in mixtures involving the PnB as well as in mixtures having very low vapor pressures, were encountered. Nevertheless, we have obtained in general a satisfactory representation of measured points regardless of those issues.
Oleksandr Dimitrov, Pierrette Guichardon, Isabelle Raspo, Evelyne Neau. Vapor–Liquid Equilibria of the Aqueous and Organic Mixtures Composed of Dipropylene Glycol Methyl Ether, Dipropylene Glycol n -Butyl Ether, and Propylene Glycol n -Butyl Ether. Part II: Modeling Based on the NRTL-PR Model. Industrial and engineering chemistry research, 2021, 60 (30), pp.11513-11524. ⟨10.1021/acs.iecr.1c01545⟩. ⟨hal-03379757⟩
Journal: Industrial and engineering chemistry research
Hadrien Jaubert, Philippe Borel, Pierrette Guichardon, Jean-François Portha, Jean-Noël Jaubert, et al.. Assessment of organic Rankine cycle configurations for solar polygeneration orientated to electricity production and desalination. Applied Thermal Engineering, 2021, 195, pp.116983. ⟨10.1016/j.applthermaleng.2021.116983⟩. ⟨hal-03597561⟩ Plus de détails...
This work addresses the polygeneration concept integrating concentrating solar power (CSP) with an organic Rankine cycle (ORC) to produce electricity and drinking water by hybrid desalination process combining reverse osmosis (RO) and low-temperature multi-effect distillation (LTMED). Experiments carried out on a bench scale RO pilot led to determine optimal operating parameters as well as options to mitigate the main limiting factors of this technology by hybridizing with LTMED. These data helped to simulate a large scale solar polygeneration plant integrating parabolic trough collectors as CSP technology and a hybrid RO-LTMED system as desalination technology. Various ORC design proposals were simulated and the optimal configuration was pointed out on the basis of thermodynamic criteria (energy efficiency and exergy destruction) and an economic analysis by using two working fluids: an alkane commonly admitted as good candidate and an ester proposed here as green alternative. Results obtained in this work contribute positively to extending the solar polygeneration for desalination and production of energy leading to future sustainable plants.
Hadrien Jaubert, Philippe Borel, Pierrette Guichardon, Jean-François Portha, Jean-Noël Jaubert, et al.. Assessment of organic Rankine cycle configurations for solar polygeneration orientated to electricity production and desalination. Applied Thermal Engineering, 2021, 195, pp.116983. ⟨10.1016/j.applthermaleng.2021.116983⟩. ⟨hal-03597561⟩
Oleksandr Dimitrov, Pierrette Guichardon, Ilham Mokbel, Fatiha Dergal, Jacques Jose. Vapor–Liquid Equilibria of the Aqueous and Organic Mixtures Composed of Dipropylene Glycol Methyl Ether, Dipropylene Glycol n -Butyl Ether, and Propylene Glycol n -Butyl Ether. Part I: Experimental Study. Industrial and engineering chemistry research, 2021, 60 (26), pp.9602-9612. ⟨10.1021/acs.iecr.1c01543⟩. ⟨hal-03515186⟩ Plus de détails...
An experimental and theoretical study was undertaken for three ether glycols (mixtures of isomers). The present paper, being the first part of a complex study, reports the experimental part of the study using a static apparatus, namely, the vapor-liquid equilibria of dipropylene glycol methyl ether (DPM), dipropylene glycol n-butyl ether (DPnB), and propylene glycol n-butyl ether (PnB), and the vapor-liquid equilibria of their pseudo-binary mixtures composed of (PnB + DPM), (DPM + DPnB), (PnB + DPnB), and the aqueous solutions of each ether. The explored temperature range is between 283.15 and 363.15 K. The experimental points were fitted using the Antoine equation. No literature data was found for comparison. The aim of this paper is not only to provide the obtained experimental data but also to highlight the eventual challenges when working with very low vapor pressure compounds and mixtures. The second part is related to a theoretical study with the development of a thermodynamic model for the representation of the experimental data.
Oleksandr Dimitrov, Pierrette Guichardon, Ilham Mokbel, Fatiha Dergal, Jacques Jose. Vapor–Liquid Equilibria of the Aqueous and Organic Mixtures Composed of Dipropylene Glycol Methyl Ether, Dipropylene Glycol n -Butyl Ether, and Propylene Glycol n -Butyl Ether. Part I: Experimental Study. Industrial and engineering chemistry research, 2021, 60 (26), pp.9602-9612. ⟨10.1021/acs.iecr.1c01543⟩. ⟨hal-03515186⟩
Journal: Industrial and engineering chemistry research
Oleksandr Dimitrov, Pierrette Guichardon, Ilham Mokbel, Fatiha Dergal, Jacques Jose. Vapor–Liquid Equilibria of the Aqueous and Organic Mixtures Composed of Dipropylene Glycol Methyl Ether, Dipropylene Glycol n -Butyl Ether, and Propylene Glycol n -Butyl Ether. Part I: Experimental Study. Industrial and engineering chemistry research, 2021, 60 (26), pp.9602-9612. ⟨10.1021/acs.iecr.1c01543⟩. ⟨hal-03597175⟩ Plus de détails...
An experimental and theoretical study was undertaken for three ether glycols (mixtures of isomers). The present paper, being the first part of a complex study, reports the experimental part of the study using a static apparatus, namely, the vapor-liquid equilibria of dipropylene glycol methyl ether (DPM), dipropylene glycol n-butyl ether (DPnB), and propylene glycol n-butyl ether (PnB), and the vapor-liquid equilibria of their pseudo-binary mixtures composed of (PnB + DPM), (DPM + DPnB), (PnB + DPnB), and the aqueous solutions of each ether. The explored temperature range is between 283.15 and 363.15 K. The experimental points were fitted using the Antoine equation. No literature data was found for comparison. The aim of this paper is not only to provide the obtained experimental data but also to highlight the eventual challenges when working with very low vapor pressure compounds and mixtures. The second part is related to a theoretical study with the development of a thermodynamic model for the representation of the experimental data.
Oleksandr Dimitrov, Pierrette Guichardon, Ilham Mokbel, Fatiha Dergal, Jacques Jose. Vapor–Liquid Equilibria of the Aqueous and Organic Mixtures Composed of Dipropylene Glycol Methyl Ether, Dipropylene Glycol n -Butyl Ether, and Propylene Glycol n -Butyl Ether. Part I: Experimental Study. Industrial and engineering chemistry research, 2021, 60 (26), pp.9602-9612. ⟨10.1021/acs.iecr.1c01543⟩. ⟨hal-03597175⟩
Journal: Industrial and engineering chemistry research
Cláudio P Fonte, David Fletcher, Pierrette Guichardon, Joelle Aubin. Simulation of micromixing in a T-mixer under laminar flow conditions. Chemical Engineering Science, 2020, 222, pp.115706. ⟨10.1016/j.ces.2020.115706⟩. ⟨hal-02892241⟩ Plus de détails...
The CFD simulation of fast reactions in laminar flows can be computationally challenging due to the lack of appropriate sub-grid micromixing models in this flow regime. In this work, simulations of micromixing via the implementation of the competitive-parallel Villermaux/Dushman reactions in a T-micromixer with square bends for Reynolds numbers in the range 60–300 are performed using both a conventional CFD approach and a novel lamellae-based model. In the first, both the hydrodynamics and the concentration fields of the reaction species are determined directly using a finite volume approach. In the second, the hydrodynamic field from the CFD calculations is coupled with a Lagrangian model that is used to perform the chemical reactions indirectly. Both sets of results are compared with previously published experimental data and show very good agreement. The lamellar model has the advantage of being much less computationally intensive than the conventional CFD approach, which requires extremely fine computational grids to resolve sharp concentration gradients. It is a promising solution to model fast chemical reactions in reactors with complex geometries in the laminar regime and for industrial applications.
Cláudio P Fonte, David Fletcher, Pierrette Guichardon, Joelle Aubin. Simulation of micromixing in a T-mixer under laminar flow conditions. Chemical Engineering Science, 2020, 222, pp.115706. ⟨10.1016/j.ces.2020.115706⟩. ⟨hal-02892241⟩
Jiupeng Du, Nelson Ibaseta, Pierrette Guichardon. Generation of an O/W emulsion in a flow-focusing microchip: importance of wetting conditions and of dynamic interfacial tension. Chemical Engineering Research and Design, 2020, ⟨10.1016/j.cherd.2020.04.012⟩. ⟨hal-02799613⟩ Plus de détails...
6 To date, there is no information on the microfluidic emulsification of dibutyl adipate and 7 n-butyl acetate in water. Since these solvents are very suitable for microencapsulation by 8 interfacial polymerization, it is highly necessary to study the emulsification behavior of these 9 solvents in microchannel. This work shows that the microfluidic emulsification of these sol-10 vents in water may fail to obtain stabilized flow regimes. This is due to droplet coalescence 11 and wall wetting, even if a hydrophilic microchip is used. Hydrodynamic results show that 12 squeezing and dripping regimes are especially affected because of the wall wetting by the 13 dispersed phase. This difficulty can be circumvented by adding a surfactant (here Tween 14 80) into the aqueous phase. However, high surfactant concentrations (ten times the crit-15 ical micelle concentration) should be used for the water-dibutyl adipate system. Indeed, 16 comparison of flow maps for several surfactant concentrations seems to indicate that the 17 dynamic interfacial tension is higher than the one expected (equilibrium), for surfactant 18 concentrations lower than one hundred times the critical micelle concentration. The esti-19 mated diffusion time of Tween 80 is compared to the droplet formation time at different 20 conditions. The choice of more appropriate dimensionless numbers to represent flow maps 21 is also discussed. 22
Jiupeng Du, Nelson Ibaseta, Pierrette Guichardon. Generation of an O/W emulsion in a flow-focusing microchip: importance of wetting conditions and of dynamic interfacial tension. Chemical Engineering Research and Design, 2020, ⟨10.1016/j.cherd.2020.04.012⟩. ⟨hal-02799613⟩
Pierre Haldenwang, Braulio Bernales, Pierrette Guichardon, Nelson Ibaseta. Simple Theoretical Results on Reversible Fouling in Cross-Flow Membrane Filtration. Membranes, 2019, Application of Membrane Filtration in Industrial Processes, and in the Treatment of Water and Industrial Wastewater), 9 (4), pp.48. ⟨10.3390/membranes9040048⟩. ⟨hal-02109009⟩ Plus de détails...
In cross-flow membrane filtration, fouling results from material deposit which clogs the membrane inner surface. This hinders filtration, which experiences the so-called limiting flux. Among the models proposed by the literature, we retain a simple one: a steady-state reversible fouling is modelled with the use of a single additional parameter, i.e., N d , the ratio of the critical concentration for deposition to the feed concentration at inlet. To focus on fouling, viscous pressure drop and osmotic (counter-)pressure have been chosen low. It results in a minimal model of fouling. Solved thoroughly with the numerical means appropriate to enforce the nonlinear coupling between permeation and concentration polarization, the model delivers novel information. It first shows that permeation is utterly governed by solute transfer, the relevant non-dimensional quantities being hence limited to N d and Pe in , the transverse Péclet number. Furthermore, when the role played by N d and moderate Pe in (say Pe in < 40) is investigated, all results can be interpreted with the use of a single non-dimensional parameter, F l , the so-called fouling number, which simply reads F l ≡ Pe in N −1 d. Now rendered possible, the overall fit of the numerical data allows us to put forward analytical final expressions, which involve all the physical parameters and allow us to retrieve the experimental trends.
Pierre Haldenwang, Braulio Bernales, Pierrette Guichardon, Nelson Ibaseta. Simple Theoretical Results on Reversible Fouling in Cross-Flow Membrane Filtration. Membranes, 2019, Application of Membrane Filtration in Industrial Processes, and in the Treatment of Water and Industrial Wastewater), 9 (4), pp.48. ⟨10.3390/membranes9040048⟩. ⟨hal-02109009⟩
Carlos Baqueiro, Nelson Ibaseta, Pierrette Guichardon, Laurent Falk. Influence of reagents choice (buffer, acid and inert salt) on triiodide production in the Villermaux–Dushman method applied to a stirred vessel. Chemical Engineering Research and Design, 2018, 136, pp.25-31. ⟨10.1016/j.cherd.2018.04.017⟩. ⟨hal-01771934⟩ Plus de détails...
This work studies how deeply the reagents choice influences micromixing characterisation by the Villermaux-Dushman method, when applying it to a 1 litre stainless steel standard vessel with two baffles, stirred by an inclined blade turbine. For the first time, borate and phosphate buffer are compared on their use in the method. It is observed that triiodide production is higher when borate buffer is used. Moreover, perchloric acid leads to higher triiodide production than sulphuric acid, when injecting the same concentration of both acids. Finally, the influence of the ionic strength is also studied, since there has been a great deal of controversy about it over the last years. The results show that the ionic strength affects triiodide production, although relatively slightly. Advice concerning the choice of the reagents is given in conclusion.
Carlos Baqueiro, Nelson Ibaseta, Pierrette Guichardon, Laurent Falk. Influence of reagents choice (buffer, acid and inert salt) on triiodide production in the Villermaux–Dushman method applied to a stirred vessel. Chemical Engineering Research and Design, 2018, 136, pp.25-31. ⟨10.1016/j.cherd.2018.04.017⟩. ⟨hal-01771934⟩
Gustavo Lopes, Nelson Ibaseta, Pierrette Guichardon, Pierre Haldenwang. Effects of solute permeability on permeation and solute rejection in membrane filtration. Chemical Engineering and Technology, 2018, 41 (4), pp.788-797. ⟨10.1002/ceat.201700203⟩. ⟨hal-01681108⟩ Plus de détails...
Membrane solute permeability plays a role in the buildup of concentration polarization in pressure-driven crossflow filtration processes, and thus in the determination of the permeate flux, solute rejection, retentate flux and concentration. We numerically examine reverse-osmosis desalination with membranes of fixed solvent permeability, but of variable selectivity with respect to the solute. The study highlights an intricate coupling between retentate and filtrate properties. In particular, it reveals that, for given values of solute permeability and feed concentration, there is a maximum operating pressure that optimizes solute rejection regardless of the feed salinity. The conditions leading to this and to other peculiar behaviors for permeation fluxes and concentrations are identified.
Gustavo Lopes, Nelson Ibaseta, Pierrette Guichardon, Pierre Haldenwang. Effects of solute permeability on permeation and solute rejection in membrane filtration. Chemical Engineering and Technology, 2018, 41 (4), pp.788-797. ⟨10.1002/ceat.201700203⟩. ⟨hal-01681108⟩
B. Bernales, Pierre Haldenwang, Pierrette Guichardon, Nelson Ibaseta. Prandtl model for concentration polarization and osmotic counter-effects in a 2-D membrane channel. Desalination, 2017, 404, pp.341 - 359. ⟨10.1016/j.desal.2016.09.026⟩. ⟨hal-01405589⟩ Plus de détails...
An accurate 2-D numerical model that accounts for concentration polarization and osmotic effects is developed for the cross-flow filtration in a membrane channel. Focused on the coupling between laminar hydrodynam-ics and mass transfer, the numerical approach solves the solute conservation equation together with the steady Navier-Stokes equations under the Prandtl approximation, which offers a simplified framework to enforce the non-linear coupling between filtration and concentration polarization at the membrane surface. The present approach is first validated thanks to the comparison with classical exact analytical solutions for hydrodynamics and/or mass transfer, as well as with approximated analytical solutions that attempted at coupling the various phenomena. The effects of the main parameters in cross-flow reverse osmosis (RO) or nanofiltration (NF) (feed concentration, axial flow rate, operating pressure and membrane permeability) on streamlines, velocity profile, longitudinal pressure drop, local permeate flux and solute concentration profile are predicted with the present numerical model, and discussed. With the use of data reported from NF and RO experiments, the Prandtl approximation model is shown to accurately correlate both average permeate flux and local solute concentration over a wide range of operating conditions.
B. Bernales, Pierre Haldenwang, Pierrette Guichardon, Nelson Ibaseta. Prandtl model for concentration polarization and osmotic counter-effects in a 2-D membrane channel. Desalination, 2017, 404, pp.341 - 359. ⟨10.1016/j.desal.2016.09.026⟩. ⟨hal-01405589⟩
Rachel Aganetti, Aymeric Lamorlette, G.R. Thorpe. The relationship between external and internal flow in a porous body using the penalisation method. International Journal of Heat and Fluid Flow, 2017, 66 (66), pp.185 - 196. ⟨10.1016/j.ijheatfluidflow.2017.06.003⟩. ⟨hal-01547073⟩ Plus de détails...
Stockpiles of organic porous materials such as biosolids, coal, compost and woodchips are susceptible to spontaneous combustion. Flow fields within such materials are induced by buoyant forces and external agents such as the wind. However, the external forces may vary on a time scale of seconds, whereas the heat, mass and momentum processes within the porous medium may occur over timescales days or months. It would be computationally prohibitive to resolve all of the timescales, hence in this paper mean external forces are coupled to the flow field within stockpiles of biosolids by means of a penalisation method. It has been determined that four variables have a profound influence of the flow fields within porous media. These are the velocity of the wind, the permeability of the porous biosolids, the angle of repose of the medium and aspect ratio of the stockpile. Four distinct flow regimes within the stockpiles have been identified. A correlation has been developed to assist managers of stockpiles, which relates mean velocities within the four flow regimes with a Darcy and Reynolds number, the aspect ratio and angle of repose. The correlation is accurate for two of the four flow regions identified, but the error in predicting the two remaining regions is relatively large. However, this error is expected to have minimal impact on estimating the time for spontaneous combustion to occur.
Rachel Aganetti, Aymeric Lamorlette, G.R. Thorpe. The relationship between external and internal flow in a porous body using the penalisation method. International Journal of Heat and Fluid Flow, 2017, 66 (66), pp.185 - 196. ⟨10.1016/j.ijheatfluidflow.2017.06.003⟩. ⟨hal-01547073⟩
Journal: International Journal of Heat and Fluid Flow
Gustavo H. Lopes, Nelson Ibaseta, Pierrette Guichardon. How can osmosis and solute diffusion be coupled for the simultaneous measurement of the solvent and solute permeabilities of membranes?. Desalination, 2016, 387 (1), pp.61-74. ⟨10.1016/j.desal.2016.03.006⟩. ⟨hal-01290973⟩ Plus de détails...
A novel experimental method and its associated model are proposed for the simultaneous determination of membrane solute and solvent permeabilities, which are essential transport parameters of reverse osmosis models used for process simulation. The method utilizes a single bench-scale batch apparatus consisting of two stirred half-cells containing solutions of different concentrations separated by a membrane across which coupled non-steady-state solute diffusion and solvent osmosis take place countercurrently in the absence of transmembrane pressure difference. Results are presented from days-long determinations of the water and sodium chloride permeabilities of Filmtec BW30 and NF270 membrane samples for initial transmembrane salt concentration differences ranging from 1 g L-1 to 35 g L-1. When used as input parameters for the simulation of pilot reverse osmosis desalination tests, the osmotic-diffusive salt permeabilities approximated the experimental rejection rates.
Gustavo H. Lopes, Nelson Ibaseta, Pierrette Guichardon. How can osmosis and solute diffusion be coupled for the simultaneous measurement of the solvent and solute permeabilities of membranes?. Desalination, 2016, 387 (1), pp.61-74. ⟨10.1016/j.desal.2016.03.006⟩. ⟨hal-01290973⟩
Gustavo Henndel . Lopes, Nelson Ibaseta, Pierrette Guichardon, Pierre Haldenwang. Predicting Permeate Fluxes and Rejection Rates in Reverse Osmosis and Tight-Nanofiltration Processes. Chemical Engineering and Technology, 2015, 38 (4), pp.585-594. ⟨10.1002/ceat.201400654⟩. ⟨hal-01135689⟩ Plus de détails...
The performance of reverse osmosis and tight nanofiltration with flat-sheet membranes can be predicted accurately. The proposed numerical model solves the local momentum and mass conservation equations in the module's feed channel with solution-diffusion boundary conditions. Both qualitative and quantitative predictions of the permeate flux and of the rejection rate are obtained with an accuracy depending on the limitations of the solution-diffusion model for describing membrane mass transport and on the value of solute permeability. As an extension of the applications to plate-and-frame modules, the ability to describe the performance of processes carried out with spiral-wound modules is also tested with own desalination experiments and with data from the literature.
Gustavo Henndel . Lopes, Nelson Ibaseta, Pierrette Guichardon, Pierre Haldenwang. Predicting Permeate Fluxes and Rejection Rates in Reverse Osmosis and Tight-Nanofiltration Processes. Chemical Engineering and Technology, 2015, 38 (4), pp.585-594. ⟨10.1002/ceat.201400654⟩. ⟨hal-01135689⟩
Gustavo Henndel Lopes, Pierrette Guichardon, Nelson Ibaseta, Pierre Haldenwang. L’eau, ressource rare ? Gros plan sur le procédé de dessalement par membranes d’osmose inverse. L'Actualité Chimique, 2014, N° thématique: La chimie et la ville de demain Colloque Recherche de la Fédération Gay-Lussac, Paris, 4-6 décembre 2013, 390, pp.85-87. ⟨hal-01116186⟩ Plus de détails...
Le procédé d’osmose inverse s’impose aujourd'hui dans la production d’eau douce par dessalement. Des avancées en matière de prédiction des performances de ce procédé s’avèrent précieuses dans l’optimisation rapide et peu coûteuse des conditions de fonctionnement. L’interaction entre les propriétés de la membrane et les phénomènes prépondérants (polarisation de concentration, pression osmotique...) constitue un problème scientifiquement complexe, traité dans cette étude via une approche modélisation numérique-simulation-expérimentation, une question centrale pour le génie des procédés.
Gustavo Henndel Lopes, Pierrette Guichardon, Nelson Ibaseta, Pierre Haldenwang. L’eau, ressource rare ? Gros plan sur le procédé de dessalement par membranes d’osmose inverse. L'Actualité Chimique, 2014, N° thématique: La chimie et la ville de demain Colloque Recherche de la Fédération Gay-Lussac, Paris, 4-6 décembre 2013, 390, pp.85-87. ⟨hal-01116186⟩
Gustavo Henndel Lopes, Pierrette Guichardon, Nelson Ibaseta, Pierre Haldenwang. L’eau, ressource rare ? Gros plan sur le procédé de dessalement par membranes d’osmose inverse
. L'Actualité Chimique, 2014, N° thématique: La chimie et la ville de demain Colloque Recherche de la Fédération Gay-Lussac, Paris, 4-6 décembre 2013, 390, pp.85-87. ⟨hal-01116186⟩ Plus de détails...
Le procédé d’osmose inverse s’impose aujourd'hui dans la production d’eau douce par dessalement. Des avancées en matière de prédiction des performances de ce procédé s’avèrent précieuses dans l’optimisation rapide et peu coûteuse des conditions de fonctionnement. L’interaction entre les propriétés de la membrane et les phénomènes prépondérants (polarisation de concentration, pression osmotique...) constitue un problème scientifiquement complexe, traité dans cette étude via une approche modélisation numérique-simulation-expérimentation, une question centrale pour le génie des procédés.
Gustavo Henndel Lopes, Pierrette Guichardon, Nelson Ibaseta, Pierre Haldenwang. L’eau, ressource rare ? Gros plan sur le procédé de dessalement par membranes d’osmose inverse
. L'Actualité Chimique, 2014, N° thématique: La chimie et la ville de demain Colloque Recherche de la Fédération Gay-Lussac, Paris, 4-6 décembre 2013, 390, pp.85-87. ⟨hal-01116186⟩
H. Hchaichi, Hamza Elfil, Pierrette Guichardon, Ahmed Hannachi. Scaling tendency assessment in reverse osmosis modules. Desalination and Water Treatment, 2013, 51 (4-6), pp.892-898. ⟨10.1080/19443994.2012.715410⟩. ⟨hal-01464722⟩ Plus de détails...
A mathematical model was developed to predict super saturation along ă reverse osmosis modules (RO) for water desalination. This model is based on conservation principles and chemical equilibrium equations for concentrated solutions. Pitzer's model was used for the activity coefficient calculations. An average rejection rate for each ionic species was also considered. Supersaturations with respect to all calcium carbonate forms and to calcium sulfate are calculated. The model allows assessing when scale is likely to occur along the RO modules. The results for two brackish water qualities and seawater are shown.
H. Hchaichi, Hamza Elfil, Pierrette Guichardon, Ahmed Hannachi. Scaling tendency assessment in reverse osmosis modules. Desalination and Water Treatment, 2013, 51 (4-6), pp.892-898. ⟨10.1080/19443994.2012.715410⟩. ⟨hal-01464722⟩
A. Leybros, A. Roubaud, Pierrette Guichardon, Olivier Boutin. Supercritical water oxidation of ion exchange resins in a stirred reactor: numerical modelling. Chemical Engineering Science, 2012, 69 (1), pp.170-180. ⟨10.1016/j.ces.2011.10.016⟩. ⟨hal-00993023⟩ Plus de détails...
Supercritical water oxidation offers a viable alternative treatment to destroy the organic structure of Ion Exchange Resins. In order to design and define appropriate dimensions for the supercritical oxidation reactor, a 2D simulation of the fluid dynamics and heat transfer during the oxidation process has been investigated. The solver used is a commercial code, Fluent® 6.3. The turbulent flow field in the reactor, created by the stirrer is taken into account with a k−ω model and a swirl imposed to the fluid. Particle trajectories are modelled with the Discrete Random Walk Particle Model. For the solubilization of the particles in supercritical water, a mechanism has been proposed and implemented into Fluent® software through the Eddy Dissipation Concept approach, taking into account the identified rate determining species. Simulation results provide results on the flow, temperature fields and oxidation localization inside the reactor. For the reactive particles-supercritical water flow model, the effect of parameters, such as feed flow rates or stirring velocity, can be focussed. Reaction temperature is predicted with deviation lower than 15%. Degradation conversions are in good agreement with experimental ones.
A. Leybros, A. Roubaud, Pierrette Guichardon, Olivier Boutin. Supercritical water oxidation of ion exchange resins in a stirred reactor: numerical modelling. Chemical Engineering Science, 2012, 69 (1), pp.170-180. ⟨10.1016/j.ces.2011.10.016⟩. ⟨hal-00993023⟩
S. Moussiere, A. Roubaud, Olivier Boutin, Pierrette Guichardon, B. Fournel, et al.. 2D and 3D CFD modelling of a reactive turbulent flow in a double shell supercritical water oxidation reactor. Journal of Supercritical Fluids, 2012, 65, pp.25-31. ⟨10.1016/j.supflu.2012.02.019⟩. ⟨hal-00992976⟩ Plus de détails...
In order to design and define appropriate dimensions for a supercritical oxidation reactor, a comparative 2D and 3D simulation of the fluid dynamics and heat transfer during an oxidation process has been performed. The solver used is a commercial code, Fluent 6.2®. The turbulent flow field in the reactor, created by the stirrer, is taken into account with a k-ω model and a swirl imposed to the fluid. In the 3D case the rotation of the stirrer can be modelled using the sliding mesh model and the moving reference frame model. This work allows comparing 2D and 3D velocity and heat transfer calculations. The predicted values (mainly species concentrations and temperature profiles) are of the same order in both cases. The reactivity of the system is taken into account with a classical Eddy Dissipation Concept combustion model. Comparisons with experimental temperature measurements validate the ability of the CFD modelling to simulate the supercritical water oxidation reactive medium. Results indicate that the flow can be considered as plug flow-like and that heat transfer is strongly enhanced by the stirring.
S. Moussiere, A. Roubaud, Olivier Boutin, Pierrette Guichardon, B. Fournel, et al.. 2D and 3D CFD modelling of a reactive turbulent flow in a double shell supercritical water oxidation reactor. Journal of Supercritical Fluids, 2012, 65, pp.25-31. ⟨10.1016/j.supflu.2012.02.019⟩. ⟨hal-00992976⟩
G.H. Lopes, B. Bernales Chavez, Nelson Ibaseta, Pierrette Guichardon, Pierre Haldenwang. Prediction of Permeate Flux and Rejection Rate in RO and NF Membrane Processes: Numerical Modelling of Hydrodynamics and Mass Transfer Coupling. Procedia Engineering, 2012, 44, pp.1934-1936. ⟨10.1016/j.proeng.2012.09.001⟩. ⟨hal-01299944⟩ Plus de détails...
G.H. Lopes, B. Bernales Chavez, Nelson Ibaseta, Pierrette Guichardon, Pierre Haldenwang. Prediction of Permeate Flux and Rejection Rate in RO and NF Membrane Processes: Numerical Modelling of Hydrodynamics and Mass Transfer Coupling. Procedia Engineering, 2012, 44, pp.1934-1936. ⟨10.1016/j.proeng.2012.09.001⟩. ⟨hal-01299944⟩
Pierre Haldenwang, Pierrette Guichardon. Pressure runaway in a 2D plane channel with permeable walls submitted to pressure-dependent suction. European Journal of Mechanics - B/Fluids, 2011, 30 (2), pp.177-183. ⟨10.1016/j.euromechflu.2010.09.007⟩. ⟨hal-00905831⟩ Plus de détails...
A leaking duct carries a flow that is a characteristic of several applications. Devices for cross-flow microfiltration are composed of a duct, the walls of which are semi-permeable membranes. In subsurface irrigation, the walls of watering pipes can be of porous clay, whereas the watering hoses are riddled with holes or made of porous material, in surface drip irrigation. In these applications, the first approach consists of assuming that the flow concerns a pure fluid (as in a microfiltration system operating at a very low species concentration), and that the wall's leakage depends only on the local pressure difference between both inner and outer sides of the wall.
Pierre Haldenwang, Pierrette Guichardon. Pressure runaway in a 2D plane channel with permeable walls submitted to pressure-dependent suction. European Journal of Mechanics - B/Fluids, 2011, 30 (2), pp.177-183. ⟨10.1016/j.euromechflu.2010.09.007⟩. ⟨hal-00905831⟩
Pierre Haldenwang, Pierrette Guichardon, Guillaume Chiavassa, N. Ibaseta. Exact solution to mass transfer in Berman flow: application to concentration polarization combined with osmosis in crossflow membrane filtration. International Journal of Heat and Mass Transfer, 2010, 53 (19-20), pp.3898-3904. ⟨10.1016/j.ijheatmasstransfer.2010.05.008⟩. ⟨hal-00907275⟩ Plus de détails...
Concentration polarization affects numerous systems of membrane separation, and combined with osmosis, it can cause substantial reductions in permeation. We establish an exact solution to the conservation law of a solute advected by Berman flow. This flow is characteristic of reverse osmosis or nanofiltration. The resulting concentration polarization is then combined with the osmosis (counter-) effect. For large Péclet number of permeation, it yields a rigorous support to the semi-empirical "film" model, and accounts for the limit flux phenomenon. The main results are summarized in a simple diagram that relates three different Péclet numbers, and show that polarization combined with osmosis can withstand operating pressure almost totally.
Pierre Haldenwang, Pierrette Guichardon, Guillaume Chiavassa, N. Ibaseta. Exact solution to mass transfer in Berman flow: application to concentration polarization combined with osmosis in crossflow membrane filtration. International Journal of Heat and Mass Transfer, 2010, 53 (19-20), pp.3898-3904. ⟨10.1016/j.ijheatmasstransfer.2010.05.008⟩. ⟨hal-00907275⟩
Journal: International Journal of Heat and Mass Transfer
A. Leybros, A. Roubaud, Pierrette Guichardon, Olivier Boutin. Ion exchange resins destruction in a stirred supercritical water oxidation reactor. Journal of Supercritical Fluids, 2010, 51 (3), pp.369-375. ⟨10.1016/j.supflu.2009.08.017⟩. ⟨hal-01025175⟩ Plus de détails...
Spent ion exchange resins (IERs) are radioactive process wastes for which there is no satisfactory industrial treatment. Supercritical water oxidation offers a viable treatment alternative to destroy the organic structure of resins, used to remove radioactivity. Up to now, studies carried out in supercritical water for IER destruction showed that degradation rates higher than 99% are difficult to obtain even using a catalyst or a large oxidant excess. In this study, a co-fuel, isopropanol, has been used in order to improve degradation rates by initiating the oxidation reaction and increasing temperature of the reaction medium. Concentrations up to 20 wt% were tested for anionic and cationic resins. Total organic carbon reduction rates higher than 99% were obtained from this process, without the use of a catalyst. The influence of operating parameters such as IERs feed concentration, nature and counterions of exchanged IERs were also studied.
A. Leybros, A. Roubaud, Pierrette Guichardon, Olivier Boutin. Ion exchange resins destruction in a stirred supercritical water oxidation reactor. Journal of Supercritical Fluids, 2010, 51 (3), pp.369-375. ⟨10.1016/j.supflu.2009.08.017⟩. ⟨hal-01025175⟩
A. Leybros, A. Roubaud, Pierrette Guichardon, Olivier Boutin. Supercritical water oxidation of ion exchange resins: degradation mechanisms. Process Safety and Environmental Protection, 2010, 88 (3), pp.213-222. ⟨10.1016/j.psep.2009.11.001⟩. ⟨hal-01025162⟩ Plus de détails...
Spent ion exchange resins are radioactive process wastes for which there is no satisfactory industrial treatment. Supercritical water oxidation could offer a viable treatment alternative to destroy the organic structure of resins and contain radioactivity. IER degradation experiments were carried out in a continuous supercritical water reactor. Total organic carbon degradation rates in the range of 95-98% were obtained depending on operating conditions. GC-MS chromatography analyses were carried out to determine intermediate products formed during the reaction. Around 50 species were identified for cationic and anionic resins. Degradation of polystyrenic structure leads to the formation of low molecular weight compounds. Benzoic acid, phenol and acetic acid are the main compounds. However, other products are detected in appreciable yields such as phenolic species or heterocycles, for anionic IERs degradation. Intermediates produced by intramolecular rearrangements are also obtained. A radical degradation mechanism is proposed for each resin. In this overall mechanism, several hypotheses are foreseen, according to HOOradical dot radical attack sites.
A. Leybros, A. Roubaud, Pierrette Guichardon, Olivier Boutin. Supercritical water oxidation of ion exchange resins: degradation mechanisms. Process Safety and Environmental Protection, 2010, 88 (3), pp.213-222. ⟨10.1016/j.psep.2009.11.001⟩. ⟨hal-01025162⟩
Journal: Process Safety and Environmental Protection
S. Moussiere, C. Joussot-Dubien, P. Guichardon, Olivier Boutin, H.-A. Turc, et al.. Modelling of heat transfer and hydrodynamic with two kinetics approaches during supercritical water oxidation process. Journal of Supercritical Fluids, 2007, 43 (2), pp.324-332. ⟨10.1016/j.supflu.2007.06.008⟩. ⟨cea-02512107⟩ Plus de détails...
Supercritical water oxidation is an innovative and very efficient process to treat hazardous organic waste. In order to better understand the complex physic phenomena involved in this process, and to design more efficient reactors or to insure future efficient scale-up, a simulation with the Computational Fluid Dynamics software FLUENT was carried out for a simple tubular reactor. The turbulent non-reactive flow is well-represented using the $\kappa-\epsilon$ model. Nevertheless, the $\kappa-\epsilon$ model gives better results when a source term is added to take into account the chemical reaction. Two approaches are used to model the reaction rate: an Arrhenius law and the Eddy Dissipation Concept (EDC) generally used to describe combustion reactions. The results of this simulation using Arrhenius law, are in good agreement with experimental data although a simple thermohydraulic model was used. Moreover, the sensitiveness to the inlet temperature has been demonstrated. It influences the reaction start-up and the shape of the measured wall temperature peak. Equally, the simulated temperature profiles using Eddy Dissipation Concept model are in good agreement with experimental ones. Hence, the two approaches give similar results. Nevertheless, the EDC model predicts more precisely the thermal peak location at the reactor wall.
S. Moussiere, C. Joussot-Dubien, P. Guichardon, Olivier Boutin, H.-A. Turc, et al.. Modelling of heat transfer and hydrodynamic with two kinetics approaches during supercritical water oxidation process. Journal of Supercritical Fluids, 2007, 43 (2), pp.324-332. ⟨10.1016/j.supflu.2007.06.008⟩. ⟨cea-02512107⟩
