Downstream variations of air-gap membrane distillation and comparative study with direct contact membrane distillation: A modelling approach
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MANUSCRIPT Abolfazi Griffith Univ Australia 2021.pdf
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2024-01-04
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ArticleAuthors
Ansari, AbolfazlGalogahi, Fariba Malekpour
Thiel, David V.
Helfer, Fernanda
Millar, Graeme
Soukane, Sofiane
Ghaffour, NorEddine

KAUST Department
Water Desalination and Reuse Research Center (WDRC)Environmental Science and Engineering Program
Biological and Environmental Science and Engineering (BESE) Division
Date
2022-01-04Embargo End Date
2024-01-04Submitted Date
2021-08-26Permanent link to this record
http://hdl.handle.net/10754/674976
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Air-Gap Membrane Distillation (AGMD) promises to reduce heat loss in membrane distillation. Most AGMD models are one-dimensional and do not consider the downstream variations. In addition, a linear function of vapour pressure is used, which either relies on experimentally determined parameters or a simplified mass transfer resistance to model the water permeate flux. This study introduces a new, improved model that simultaneously considers both heat and mass transfer in the AGMD process by coupling the continuity, momentum, and energy equations. A novel precise logarithmic function of vapour pressure was derived to model the water permeate flux, independent of experimentally determined parameters. By varying the inlet temperature, Reynolds number, inlet concentration, and air-gap thickness, the performance of AGMD was evaluated. The results revealed that our model improved the water flux prediction from more than 10% to less than 4% deviation from experimental results. Among the operating conditions, only increasing the Reynolds number improved all the system performance metrics, including higher water flux and lower temperature and concentration polarisation effects. Results were compared with Direct Contact Membrane Distillation (DCMD) outcomes and showed that unlike AGMD, DCMD suffers from a substantial decrease in water flux along the module. For DCMD, the exit water flux value decreased by 50% in comparison with the inlet value, while the water flux decreased by only 2% for AGMD, using a 1 mm air gap thickness.Citation
Ansari, A., Galogahi, F. M., Thiel, D. V., Helfer, F., Millar, G., Soukane, S., & Ghaffour, N. (2022). Downstream variations of air-gap membrane distillation and comparative study with direct contact membrane distillation: A modelling approach. Desalination, 526, 115539. doi:10.1016/j.desal.2021.115539Publisher
Elsevier BVJournal
DesalinationAdditional Links
https://linkinghub.elsevier.com/retrieve/pii/S001191642100610Xae974a485f413a2113503eed53cd6c53
10.1016/j.desal.2021.115539