Numerical and experimental methodology for the development of a new membrane prototype intended to microfiltration bioprocesses. Application to milk filtration

International audienceIn tangential flow filtration, the non-uniform TransMembrane Pressure (TMP) on the membrane length produces a non homogeneous filtration cake, initiates process selectivity changes and modifies the permeate quality. The purpose of this study is to create a tubular ceramic membrane prototype with a more uniform TMP, intended to filtration of fouling fluids. The principle of this membrane structure is to waterproof the external membrane surface to limit flow circulation in the porous support of the membrane. The production was controlled by sizing "permeation vents". This development was achieved using a CFD modelling tool interacting with experiments. A preliminary modelling study was made with water. This work was afterwards applied to the industrial process of casein micelle separation from skim milk. The influence of operating conditions on the membrane hydrodynamics was highlighted. The modelling results were experimentally confirmed, with a discrepancy smaller than 3% and a reproducible water permeability of 2.3 L h−1 bar−1 for 1 mm-wide vent (TMP = 1 bar, T = 20 °C). Then, milk filtration experiments showed a production ratio milk/water equal to 1/2. The permeate quality parameters were studied and the fouling phenomena were taken into account. A parametric study led to the sizing of a final prototype. Its efficiency was experimentally evaluated

Optimizing the compacity of ceramic membranes

International audienceThe aim of this study is to increase exchange area or specific area of the membrane unit containing the ceramic membranes in order to achieve a compacity of over 330 m2/m3. Several configurations were studied by varying parameters like the diameter, membrane geometry, and the form of channels (cylindrical, square-section, triangular, hexagonal, etc.). Taking manufacturing constraints into account, several optimized geometries were described, thus allowing the optimization of the filtration area for each module. In this way, membrane compacity was significantly improved. Therefore a substantial increase in the permeate flux was expected and it was important to verify the capacity of the porous media to evacuate such permeate flux. Computational fluid dynamics analysis was used to simulate permeate evacuation as well as the flow-rate of each individual channel in the monolith. The optimal geometries could then be determined as a function of this permeate flow-rate and/or cut-off threshold. The experimental results obtained with water were in good agreement with those obtained by numerical simulation

Numerical and Experimental Methodology for the Development of a New Membrane Prototype Intended to Microfiltration Bioprocesses. Application to Milk Filtration

In tangential flow filtration, the non-uniform TransMembrane Pressure (TMP) on the membrane length produces a non homogeneous filtration cake, initiates process selectivity changes and modifies the permeate quality. The purpose of this study is to create a tubular ceramic membrane prototype with a more uniform TMP, intended to filtration of fouling fluids. The principle of this membrane structure is to waterproof the external membrane surface to limit flow circulation in the porous support of the membrane. The production was controlled by sizing «permeation vents». This development was achieved using a CFD modelling tool interacting with experiments. A preliminary modelling study was made with water. This work was afterwards applied to the industrial process of casein micelle separation from skim milk. The influence of operating conditions on the membrane hydrodynamics was highlighted. The modelling results were experimentally confirmed, with a discrepancy smaller than 3% and a reproducible water permeability of 2.3 L h−1 bar−1 for 1 mm-wide vent (TMP = 1 bar, T = 20 ◦C). Then, milk filtration experiments showed a production ratio milk/water equal to 1/2. The permeate quality parameters were studied and the fouling phenomena were taken into account. A parametric study led to the sizing of a final prototype. Its efficiency was experimentally evaluated.JRC.F.2-Cleaner energ

Développement d'un système de purification par pervaporation pour le recyclage de solvants

International audienc

Study of the Effect of Geometry on Wall Shear Stress and Permeate Flux for Ceramic Membranes: CFD and Experimental Approaches

International audienceKnowing how wall shear stress develops at the membrane surface is extremely useful when trying to reduce concentration polarization and fouling. Newly developed as well as manufactured ceramic membranes exhibit various channel geometries (cylindrical, square, triangular, etc). Mass transport characteristics depend on the geometry that conditions hydrodynamic conditions. The goal of this work is to study the influence of the channel geometry on the wall shear stress for various operating parameters (tangential velocity, transmembrane pressure…). Numerical simulations are performed for various inlet velocities for different channel geometries. The wall shear stress along the channel perimeter as a function of the shape and the cross section of the channel are studied. The influence of the geometry on the membrane performances is also studied. The simulated shear stress is employed to correlate experimental results. The results of this comparison show that mass transfer resistance depends on the wall shear stress alone, regardless of the flow rate, the shape or section of the channels

Membrane filtration process adapted for water treatment of aerated sewage lagoons

International audienceno abstrac

Développement d’un nouveau procédé de filtration membranaire en lagune d’épuration pour la réutilisation en eaux usées

National audienceno abstrac

Development of a new membrane filtration process adapted for water treatment of sewage lagoons

International audienceno abstrac

Novel concept for the preparation of gas selective nanocomposite membranes

In this work we report on a novel concept for the preparation of gas selective composite membranes by a simple and robust synthesis protocol involving a controlled in-situpolycondensation of functional alkoxysilanes within the pores of a mesoporous ceramic matrix. This innovative approach targets the manufacture of thin nanocomposite membranes, allowing good compromise between permeability, selectivity and thermomechanical strength. Compared to simple infiltration, the synthesis protocol allows a controlled formation of gas separation membranes from size-adjusted functional alkoxysilanes by a chemical reaction within the mesopores of a ceramic support, without any formation of a thick and continuous layer on the support top-surface. Membrane permeability can thus be effectively controlled by the thickness and pore size of the mesoporous layer, and by the oligomers chain length. The as-prepared composite membranes are expected to possess a good mechanical and thermomechanical resistance and exhibit a thermally activated transport of He and H2 up to 150 ∘C, resulting in enhanced separation factors for specific gas mixtures e.g. FH2/CO ∼ 10; FH2/CO2 ∼ 3; FH2/CH4 ∼ 62