School of Civil and Environmental Engineering
Ph.D. Thesis Defense Announcement
Ion exchange membrane systems: modeling and optimization for salinity gradient energy generation
By
Bopeng Zhang
Advisor:
Dr. Yongsheng Chen (CEE)
Committee Members:
Dr. Yongsheng Chen (Advisor, CEE); Dr. John Crittenden (CEE); Dr. Sotira Yiacoumi (CEE); Dr. Shuman Xia (Mechanical Engineering); Dr. Xing Xie (CEE)
Date & Time: Wednesday, May 2nd, 2018 , 10:00AM
Location: Sustainable Education Building, 122
Energy can be sustainably generated by harnessing natural salinity gradients in coastal environments. Power derived
from the mixing of freshwater and seawater can be recovered as electrical energy by regulated ion transport in reverse
electrodialysis (RED) systems. Cation exchange membranes and anion exchange membranes, known together as ion
exchange membranes (IEMs), are crucial components to the energy generation efficiency in RED stacks. Considering
the fundamental nature of electrochemical systems, it is conceivable that membrane functional properties, including
ionic conductivity and permselectivity, have significant effects on RED energy performance. A better understanding
of these determining factors is therefore critical to advance commercialization feasibility.
This study focused on advancing the understanding of IEMs through modeling, simulation and experimental
validation in addition to novel approaches for RED energy performance improvement. Specifically, conductivity
gains were realized through implementation of ion exchange resin in low-concentration compartments. Mathematical
modeling and experimental validation were leveraged to infer crucial factors in membrane conductivity and other
physical property determinations. In addition, this framework was extended to illuminate the role of nanoparticle
introduction during the synthesis process.
Modeling and simulation results were successful in revealing the underlying dependencies of IEM characterization
and improving the system energy performance. A majority of these theories and simulations are generalized -
potentially yielding broad impacts to similar membrane-based systems and processes (e.g., electrodialysis).
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