Salinity Gradients for Sustainable Energy: Primer, Progress, and Prospects

Yip, Ngai Yin; Brogioli, Doriano; Hamelers, H.V.M.; Nijmeijer, Kitty

doi:10.1021/acs.est.6b03448

Cited by 272 publications

(172 citation statements)

References 277 publications

Supporting

Mentioning

171

Contrasting

Unclassified

Order By: Relevance

“…To perform electrical work, a hydroturbine can be used to accomplish depressurization. 18 Besides being an environmentally friendly technology, the PRO system continues to attract attention mainly because the world osmotic energy is estimated to be in the order of 1750-2000 TWh per year, which could be improved if we consider brine and brackish. 15 In 1954, Pattle 19 was the first to introduce the idea that the mixture of a pure solute with a solution constitutes an energy source.…”

Section: Salinity and Proton Gradient Energy-based Systemsmentioning

confidence: 99%

Electrochemical Systems for Renewable Energy Conversion from Salinity and Proton Gradients

Morais¹,

Lima²,

Gomes³

et al. 2018

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

Ever-rising energy demand, fossil fuel dependence, and climate issues have harmful consequences to the society. Exploring clean and renewable energy to diversify the world energy matrix has become an urgent matter. Less explored or unexplored renewable energy sources like the salinity and proton gradient energy are an attractive alternative with great energy potential. This paper discusses important electrochemical systems for energy conversion from natural and artificial concentration gradients, namely capacitive mixing (CapMix), mixing entropy batteries (MEB), and neutralization batteries (NB); the working principle and thermodynamic formalism of these systems; and the materials employed in the assembly of these systems.

show abstract

Section: Salinity and Proton Gradient Energy-based Systemsmentioning

confidence: 99%

Electrochemical Systems for Renewable Energy Conversion from Salinity and Proton Gradients

Morais¹,

Lima²,

Gomes³

et al. 2018

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

show abstract

“…Natural salinity gradient ubiquitously existing between seawater and river water is considered an important source of renewable energy . When the seawater and river water are separated by an ion‐exchange membrane, the difference in the electrochemical potential between the two solutions results in a directional transport of ions across the ion‐exchange membrane, which converts the salinity gradient into electric energy [1f,2]. However, the present power density from salinity gradient is generally limited by high cost and low ion flux of the ion‐exchange membrane [1f,3].…”

Section: Introductionmentioning

confidence: 99%

pH‐Resistant Nanofluidic Diode Membrane for High‐Performance Conversion of Salinity Gradient into Electric Energy

et al. 2019

View full text Add to dashboard Cite

The harvesting of the energy stored in the salinity gradient between seawater and river water by a membrane‐scale nanofluidic diode for sustainable generation of electricity is attracting significant attention in recent years. However, the performance of previously reported nanofluidic diodes is sensitive to the pH conditions, which restricts their potential applications in wider fields with variable pH values. Herein, a pH‐resistant membrane‐scale nanofluidic diode with a high ion rectification ratio of ≈85 that demonstrates a stable ion rectification property over a wider pH range from 4 to 10 is reported. This pH‐resistant ion rectification is explained quantitatively by a theoretical calculation based on the Poisson and Nernst–Plank equations. The nanofluidic diode membrane is integrated into a power generation device to harvest the energy stored in the salinity gradient. By mixing the simulated seawater (0.5 m KCl) and river water (0.01 m KCl) through the membrane, the device outputs an impressive power density of 3.15 W m−2 and demonstrates high stability over a wider pH range. The membrane‐scale nanofluidic diode provides a pH‐resistant platform to control the ion transport and to convert the salinity gradient into electric energy.

show abstract

“…The main technologies developed for that purpose to date, namely, pressure-retarded osmosis and reverse electrodialysis, exploit the osmotic pressure difference using hydrostatic pressure or electric potential differences applied across membranes [6]. Despite the promises of these approaches-in particular, thanks to the control of flow through single nanotubes for the design of improved membranes [7]-a completely different strategy is also under consideration, to avoid the efficiency loss induced by membrane fouling.…”

Section: Introductionmentioning

confidence: 99%

Blue Energy and Desalination with Nanoporous Carbon Electrodes: Capacitance from Molecular Simulations to Continuous Models

et al. 2018

View full text Add to dashboard Cite

Capacitive mixing (CapMix) and capacitive deionization (CDI) are currently developed as alternatives to membrane-based processes to harvest blue energy-from salinity gradients between river and sea waterand to desalinate water-using charge-discharge cycles of capacitors. Nanoporous electrodes increase the contact area with the electrolyte and hence, in principle, also the performance of the process. However, models to design and optimize devices should be used with caution when the size of the pores becomes comparable to that of ions and water molecules. Here, we address this issue by simulating realistic capacitors based on aqueous electrolytes and nanoporous carbide-derived carbon (CDC) electrodes, accounting for both their complex structure and their polarization by the electrolyte under applied voltage. We compute the capacitance for two salt concentrations and validate our simulations by comparison with cyclic voltammetry experiments. We discuss the predictions of Debye-Hückel and Poisson-Boltzmann theories, as well as modified Donnan models, and we show that the latter can be parametrized using the molecular simulation results at high concentration. This then allows us to extrapolate the capacitance and salt adsorption capacity at lower concentrations, which cannot be simulated, finding a reasonable agreement with the experimental capacitance. We analyze the solvation of ions and their confinement within the electrodes-microscopic properties that are much more difficult to obtain experimentally than the electrochemical response but very important to understand the mechanisms at play. We finally discuss the implications of our findings for CapMix and CDI, both from the modeling point of view and from the use of CDCs in these contexts.

show abstract

Salinity Gradients for Sustainable Energy: Primer, Progress, and Prospects

Cited by 272 publications

References 277 publications

Electrochemical Systems for Renewable Energy Conversion from Salinity and Proton Gradients

Electrochemical Systems for Renewable Energy Conversion from Salinity and Proton Gradients

pH‐Resistant Nanofluidic Diode Membrane for High‐Performance Conversion of Salinity Gradient into Electric Energy

Blue Energy and Desalination with Nanoporous Carbon Electrodes: Capacitance from Molecular Simulations to Continuous Models

Contact Info

Product

Resources

About