@article { ISI:000309890700003, title = {Heat and mass transfer analysis in air gap membrane distillation process for desalination}, journal = {Membrane Water Treatment}, volume = {2}, number = {3}, year = {2011}, month = {JUL}, pages = {159-173}, publisher = {TECHNO-PRESS}, address = {PO BOX 33, YUSEONG, DAEJEON 305-600, SOUTH KOREA}, abstract = {

The air gap membrane distillation (AGMD) process was applied for water desalination. The main objective of the present work was to study the heat and mass transfer mechanism of the process. The experiments were performed on a flat sheet module using aqueous NaCl solutions as a feed. The membrane employed was hydrophobic PTFE of pore size 0.22 mu m. A mathematical model is proposed to evaluate the membrane mass transfer coefficient, thermal boundary layers{\textquoteright} heat transfer coefficients, membrane/liquid interface temperatures and the temperature polarization coefficients. The mass transfer model was validated by the experimentally and fitted well with the combined Knudsen and molecular diffusion mechanism. The mass transfer coefficient increased with an increase in feed bulk temperature. The experimental parameters such as, feed temperature, 313 to 333 K, feed velocity, 0.8 to 1.8 m/s (turbulent flow region) were analyzed. The permeation fluxes increased with feed temperature and velocity. The effect of feed bulk temperature on the boundary layers{\textquoteright} heat transfer coefficients was shown and fairly discussed. The temperature polarization coefficient increased with feed velocity and decreased with temperature. The values obtained were 0.56 to 0.82, indicating the effective heat transfer of the system. The fouling was observed during the 90 h experimental run in the application of natural ground water and seawater. The time dependent fouling resistance can be added in the total transport resistance.

}, keywords = {AGMD, Desalination, heat transfer coefficient, mass transfer coefficient, temperature polarization coefficient}, issn = {2005-8624}, author = {Pangarkar, Bhausaheb L. and Sane, Mukund G.} } @article { ISI:000340931800032, title = {Unusual behavior of propane as a co-guest during hydrate formation in silica sand: potential application to seawater desalination and carbon dioxide capture}, journal = {Chemical Engineering Science}, volume = {117}, year = {2014}, month = {SEP}, pages = {342-351}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

We report an unusual behavior of hydrate formation in silica sand with gas mixtures containing propane as a co-guest. Based on morphology study we observed that propane as a co-guest has the ability to draw water dispersed in silica sand to the hydrate formation region and showed a tendency to result in drastic hydrate growth due to the migration of water molecules to the gas phase region. Hydrate nucleation occurred in the interstitial pore space between the silica sand particles and hydrate growth occurred in the gas phase above the silica sand bed and to sustain the hydrate growth, dispersed water was drawn towards the hydrate growth front. In addition, we elucidated the effect of sand bed height to maximize the growth rates utilizing this behavior that results in enhanced kinetics. We propose conceptual designs for utilizing this behavior of propane as a co-guest in sand for seawater desalination and an innovative approach to simultaneously capture carbon dioxide and desalinate seawater. (C) 2014 Elsevier Ltd. All rights reserved.

}, keywords = {Carbon dioxide capture, Desalination, Enhanced kinetics, Gas hydrates, Propane hydrate: pre-combusuon capture}, issn = {0009-2509}, doi = {10.1016/j.ces.2014.06.044}, author = {Babu, Ponnivalavan and Kumar, Rajnish and Linga, Praveen} } @article {44235, title = {Carbon fabric based solar steam generation for waste water treatment}, journal = {Solar Energy}, volume = {159}, year = {2018}, month = {JAN}, pages = {800-810}, type = {Article}, abstract = {

Decontamination of waste water is one of the most practical techniques to tackle the worldwide clean water shortage. In recent times, solar steam based decontamination of contaminated water has been attested as a potential sustainable strategy to get clean water using renewable resources. Herein, we report the utilization of Carbon fabric and Titanium Nanorods on Carbon Fabric for solar steam based water purification techniques. The performance of Carbon Fabric was tested under different conditions and the results proved that Carbon Fabric has excellent light to heat conversion capabilities in both real and ideal conditions. Owing to the excellent performance of Carbon Fabric, it was used for purification of different types of contaminated water. About 99.9\% of salt and 87\% of organic contaminants were removed from saline water and organic waste water respectively, using a simple low cost carbon fabric based homemade prototype. We also present the application of Titanium Nanorods on carbon fabric for the efficient removal of dye molecules like Rhodamine B from contaminated water using solar driven interfacial steam generation mechanism.

}, keywords = {Desalination, Dye degradation, Solar steam, Waste water treatment}, issn = {0038-092X}, doi = {10.1016/j.solener.2017.11.055}, author = {Higgins, M. W. and Rahmaan, Shakeel A. R. and Devarapalli, Rami Reddy and Shelke, Manjusha V. and Jha, Neetu} } @article {49564, title = {Highly permselective contorted polyamide desalination membranes with enhanced free volume fabricated by mLbL assembly}, journal = {ACS Applied Materials \& Interfaces}, volume = {17}, year = {2025}, month = {JAN}, pages = {9716-9727}, type = {Article}, abstract = {

The permeability-selectivity trade-off in polymeric desalination membranes limits the efficiency and increases the costs of reverse osmosis and nanofiltration systems. Ultrathin contorted polyamide films with enhanced free volume demonstrate an impressive 8-fold increase in water permeance while maintaining equivalent salt rejection compared to conventional polyamide membranes made with m-phenylenediamine and trimesoyl chloride monomers. The solution-based molecular layer-by-layer (mLbL) deposition technique employed for membrane fabrication sequentially reacts a shape-persistent contorted diamine monomer with a trimesoyl chloride monomer, forming highly cross-linked, dense polyamide networks while avoiding the kinetic and mass transfer limitations of traditional interfacial polymerization. The mLbL process allows precise nanoscale control over polyamide selective layer thickness, network structure, and surface roughness. The resulting controlled film thicknesses enable direct measurements of water and NaCl permeabilities. The permselectivities of contorted polyamide membranes surpass those of commercial desalination membranes and approach the reported polyamide upper bound. Solution-diffusion transport modeling indicates that this high permselectivity may be attributed to enhanced water transport pathways in the contorted polyamides that increase water diffusivity-permeability while maintaining high solute rejection through solubility-selectivity.

}, keywords = {Desalination, molecular layer-by-layer assembly, permselectivity, polyamide, polymers of intrinsicmicroporosity, triptycene, Troger{\textquoteright}s base}, issn = {1944-8244}, doi = {10.1021/acsami.4c14332}, author = {Shaligram, Sayali and Shevate, Rahul and Paul, Siddhartha and Shaffer, Devin L.} }