TY - JOUR
T1 - Influence of microporous membrane properties on the desalination performance in direct contact membrane distillation
AU - Li, Lin
AU - Sirkar, Kamalesh K.
N1 - Funding Information:
The authors gratefully acknowledge support for this research from the NSF Industry/University Cooperative Research Center for Membrane Science, Engineering and Technology that has been supported via NSF Award IIP1034720.
Publisher Copyright:
© 2016 Elsevier B.V.
PY - 2016/9/1
Y1 - 2016/9/1
N2 - To evaluate the influence of membrane properties on direct contact membrane distillation (DCMD) performance, a variety of microporous hydrophobic flat sheet membranes of polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE) were employed in this study over a range of hot brine temperatures, 65-85 °C. The membrane thickness was varied between 23 μm and 125 μm; the nominal pore size was varied from 0.05 μm to 0.45 μm; the porosity was generally high in the range of 0.7-0.8. Experiments were done using two different flat test cells, a stainless steel cell and a chlorinated polyvinyl chloride (CPVC) cell. Boundary layer heat transfer resistances in the membrane cell on both sides of the membrane and the two membrane surface temperatures were determined from the experimental data over a range of hot brine and cold distillate flow rates by the Wilson plot technique. Membrane properties such as the maximum pore size and tortuosity were characterized and employed in checking out model assumptions and model results for water vapor transport in the Knudsen regime and the transition region. Good agreements (within 5% deviation) of the membrane mass transfer coefficient of water vapor and the observed water vapor fluxes were obtained between the experimental values and the simulated results predicted for either the Knudsen regime or the transition region.
AB - To evaluate the influence of membrane properties on direct contact membrane distillation (DCMD) performance, a variety of microporous hydrophobic flat sheet membranes of polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE) were employed in this study over a range of hot brine temperatures, 65-85 °C. The membrane thickness was varied between 23 μm and 125 μm; the nominal pore size was varied from 0.05 μm to 0.45 μm; the porosity was generally high in the range of 0.7-0.8. Experiments were done using two different flat test cells, a stainless steel cell and a chlorinated polyvinyl chloride (CPVC) cell. Boundary layer heat transfer resistances in the membrane cell on both sides of the membrane and the two membrane surface temperatures were determined from the experimental data over a range of hot brine and cold distillate flow rates by the Wilson plot technique. Membrane properties such as the maximum pore size and tortuosity were characterized and employed in checking out model assumptions and model results for water vapor transport in the Knudsen regime and the transition region. Good agreements (within 5% deviation) of the membrane mass transfer coefficient of water vapor and the observed water vapor fluxes were obtained between the experimental values and the simulated results predicted for either the Knudsen regime or the transition region.
KW - Direct contact membrane distillation
KW - Knudsen diffusion/transition regime
KW - Membrane tortuosity
KW - PVDF and ePTFE membranes
KW - Wilson Plot
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U2 - 10.1016/j.memsci.2016.04.015
DO - 10.1016/j.memsci.2016.04.015
M3 - Article
AN - SCOPUS:84964957730
SN - 0376-7388
VL - 513
SP - 280
EP - 293
JO - Journal of Membrane Science
JF - Journal of Membrane Science
ER -