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Multi-Effect Vacuum Membrane Distillation systems: Model derivation and calibration
Vacuum Membrane Distillation (VMD) has been shown to be a promising desalination approach when going beyond the application range of Reverse Osmosis. Multi-stage arrangements in particular benefit from system-inherent heat recovery and thus yield low specific energy demand. Nevertheless, these syste...
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Published in: | Desalination 2018-07, Vol.438, p.97-111 |
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Main Authors: | , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | Vacuum Membrane Distillation (VMD) has been shown to be a promising desalination approach when going beyond the application range of Reverse Osmosis. Multi-stage arrangements in particular benefit from system-inherent heat recovery and thus yield low specific energy demand. Nevertheless, these systems show a complex behavior and therefore require a careful design, especially for higher salt concentrations which provide significant vapor pressure reduction. Previous experimental studies showed a need for a reliable system simulation tool, which we derived and calibrated in this work. The focus was on accurate modeling of the physical behavior, especially the multi-staging, polarization effects and different salt solutions up to their solubility limit. The model calibration and verification were based on results yielded by a novel triple channel VMD bench scale test cell, as well as technical scale system results from experiments with a memsys 2/4-stage Multi-Effect Vacuum Membrane Distillation (MEVMD) plant. The developed model was able to reproduce the system behavior and provides a tool for system optimization while providing insight into channel coupling, pressure staging, and phenomena like self-reduction of the number of working stages with rising feed salt concentration.
•A model for Multi-Effect Vacuum Membrane Distillation (MEVMD) systems is derived.•Experiments with a triple channel Vacuum Membrane Distillation test rig•Comparison with experimental results of a commercial MEVMD system•At low feed vapor pressures, a self-controlled reduction of working stages takes place.•Feed preheating and the installed number of stages are key optimization parameters. |
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ISSN: | 0011-9164 1873-4464 |
DOI: | 10.1016/j.desal.2018.03.024 |