Abstract
Most previous studies of air- and liquid-gap membrane distillation (AGMD and LGMD) processes using a composite membrane have been focused on an experimental approach. In this paper, rigorous theoretical investigations of the AGMD and LGMD processes were performed with a flat sheet type module using a composite membrane comprised of a polytetrafluoroethylene (PTFE) active layer and a polypropylene (PP) support layer. The model predictions were verified by comparing with measured data, where good agreement between the prediction results and experimental data was obtained. It was observed that as the gap size increased the AGMD permeate flux decreased exponentially with increased diffusion resistance. On the other hand, the LGMD permeate flux decreased exponentially and then increased asymptotically after attaining a minimum at a certain liquid-gap size (5–7 mm). This phenomenon was due to the onset and enhancement of a natural convection, resulting in an improvement in heat and mass transfer in the liquid gap.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 14-24 |
| Number of pages | 11 |
| Journal | Journal of Membrane Science |
| Volume | 565 |
| DOIs | |
| State | Published - Nov 1 2018 |
Bibliographical note
Funding Information:This work was supported by the Korea Institute of Energy Technology Evaluation and Planning (KETEP) funded by the Ministry of Trade, Industry & Energy (MOTIE) of the Republic of Korea (No. 20153010130460 and No. 20174010201310 ).
Publisher Copyright:
© 2018 Elsevier B.V.
Keywords
- Air-gap membrane distillation
- Composite membrane
- Desalination
- Heat and mass transfer
- Liquid-gap membrane distillation
ASJC Scopus subject areas
- Biochemistry
- Materials Science(all)
- Physical and Theoretical Chemistry
- Filtration and Separation