Loading...
Instigating buoyancy driven convection to improve membrane distillation performance
Mabry, Miles
Mabry, Miles
Citations
Altmetric:
Advisor
Editor
Date
Date Issued
2023
Date Submitted
Keywords
Collections
Research Projects
Organizational Units
Journal Issue
Embargo Expires
Abstract
Membrane distillation is a thermally driven desalination process that is capable of treating complicated
wastewaters with high concentrations of dissolved solids. However, temperature polarization and
concentration polarization reduce its distillate production and impede its industrial adoption. Surprisingly,
no prior work has considered that temperature and concentration polarization both increase the feed
density near the membrane. In this exploratory study, we explore whether these differences in local feed
density can instigate buoyancy driven convection in the feed flow and mitigate polarization. We also
explore whether we can strengthen this convection by actively heating the feed channel in a direct contact
membrane distillation (DCMD) system. For that purpose, we develop several actively heated prototypes
and perform a series of experiments to explore how active heating affects distillate production. The
prototypes are tested in multiple orientations to determine if buoyancy driven convection is truly taking
place. The tests are also performed at multiple feed flowrates and feed concentrations to explore how
temperature and concentration polarization affect the development of buoyancy driven convection.
Overall, our experiments suggest that, with the cell oriented properly, buoyancy driven convection can
be harnessed to significantly improve distillate production. For all flowrates tested, we observed a linear
increase in distillate flux with increasing wall heating. The impact of wall heating also increases as the
flowrate decreases.
Associated Publications
Rights
Copyright of the original work is retained by the author.