Experimental and Theoretical Investigation of Thin ZIF-8/Chitosan Coated Layer on Air Gap Membrane Distillation Performance of PVDF Membrane. Experimental and Theoretical Investigation of Air Gap Membrane Distillation Process for Water Desalination. Modelling Mass Transport within the Membrane of Direct Contact Membrane Distillation Modules Used for Desalination and Wastewater Treatment: Scrutinising Assumptions. Comprehensive Review of Membrane Design and Synthesis for Membrane Distillation. Membrane Distillation-Principles and Applications Elsevier: Amsterdam, The Netherlands, 2011. Membrane Contactors: Fundamentals, Applications and Potentialities Elsevier: Amsterdam, The Netherlands, 2006. Membrane Distillation: A Comprehensive Review. Emerging Desalination Technologies: Current Status, Challenges and Future Trends. ![]() Thermal conductivity of titania (the solid portion of the membrane) was taken from. Layer j (j = S for support, j = 1 for layer1, j = 2 for layer 2, j = 3 for layer 3)Īppendix A. ![]() Mean porosity-tortuosity ratio of the membrane Porosity-tortuosity ratio of the membrane layer j Gas interstitial velocity in shell-side (defined in Equation (21))Īctivity coefficient of water at liquid/membrane interface Liquid velocity in lumen-side (defined in Equation (15)) Net transmembrane heat flow rate per unit length per fiber Heat flow rate per unit length per fiber in the liquid thermal boundary layer Transmembrane Molar flow rate of water per unit length per fiber Total mass of solution in the liquid side Pseudo-thermal conductivity of the membrane (defined in Equation (9a))Įffective length of membrane module ( Figure 1c) Mass transfer coefficient of salt in liquid Mass flux of water across the membrane (defined in Equation (2)) Molecular diffusion coefficient of water in gasĮquivalent diffusion coefficient of water Logarithmic mean diameter of the membrane layer j Logarithmic mean diameter of the membraneĭ l m, m = d O U T − d I N ln d O U T d I N Molar, mass, heat capacity at constant pressure The authors declare no conflict of interest. Process efficiency should be the optimal balance between the concomitant effects of temperature and velocity of the liquid phase and pressure and velocity of the gas phase. ![]() Finally, the model has been used to investigate the role of operative parameters on process performances. ![]() In contrast, the agreement between the modeled fluxes and the experimental values is very interesting when the LBL parameters are used, with a discrepancy on the order of +/−30%. Comparison of the modeling results with experimental data highlights that the use of parameters averaged over the entire membrane leads to an overestimation by a factor of two to eight of the modeled fluxes, with respect to the experimental values. Contrary to what is generally performed for polymeric membranes and also suggested by other authors for ceramic membranes, the mass transfer across the membrane should be simulated using the corresponding values of the mean pore diameter and the porosity-tortuosity ratio of each layer and measured by the layer-by-layer (LBL) method. As a case study, capillary four-layer hydrophobic carbon-based titania membranes arranged in bundles in a shell-and-tube configuration were tested with NaCl-water solutions using air as sweeping gas, operating at temperatures from 40 to 110 ☌ and at pressures up to 5.3 bar. This paper shows which morphological characterization method is most appropriate to simulating membrane performance in sweeping gas membrane distillation in the case of multilayer hydrophobized ceramic membranes.
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