Chemical and Energy Recovery Alternatives in SWRO Desalination through Electro-Membrane Technologies

Electro-membrane technologies are versatile processes that could contribute towards more sustainable seawater reverse osmosis (SWRO) desalination in both freshwater production and brine management, facilitating the recovery of materials and energy and driving the introduction of the circular economy paradigm in the desalination industry. Besides the potential possibilities, the implementation of electro-membrane technologies remains a challenge. The aim of this work is to present and evaluate different alternatives for harvesting renewable energy and the recovery of chemicals on an SWRO facility by means of electro-membrane technology. Acid and base self-supply by means of electrodialysis with bipolar membranes is considered, together with salinity gradient energy harvesting by means of reverse electrodialysis and pH gradient energy by means of reverse electrodialysis with bipolar membranes. The potential benefits of the proposed alternatives rely on environmental impact reduction is three-fold: (a) water bodies protection, as direct brine discharge is avoided, (b) improvements in the climate change indicator, as the recovery of renewable energy reduces the indirect emissions related to energy production, and (c) reduction of raw material consumption, as the main chemicals used in the facility are produced in-situ. Moreover, further development towards an increase in their technology readiness level (TRL) and cost reduction are the main challenges to face.

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Salinity gradient energy harvested from thermal desalination for power production by reverse electrodialysis

Energy Conversion and Management ◽

10.1016/j.enconman.2021.115043 ◽

2021 ◽

pp. 115043

Author(s):

Jianbo Li ◽

Chen Zhang ◽

Zhihao Wang ◽

Zhongchao Bai ◽

Xiangqiang Kong

Keyword(s):

Salinity Gradient ◽

Power Production ◽

Reverse Electrodialysis ◽

Thermal Desalination ◽

Gradient Energy

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Reverse electrodialysis in bilayer nanochannels: salinity gradient-driven power generation

Physical Chemistry Chemical Physics ◽

10.1039/c7cp08394g ◽

2018 ◽

Vol 20 (10) ◽

pp. 7295-7302 ◽

Cited By ~ 24

Author(s):

Rui Long ◽

Zhengfei Kuang ◽

Zhichun Liu ◽

Wei Liu

Keyword(s):

Power Generation ◽

Energy Harvesting ◽

Salinity Gradient ◽

Reverse Electrodialysis ◽

Gradient Energy ◽

Ion Transportation

To evaluate the possibility of nano-fluidic reverse electrodialysis (RED) for salinity gradient energy harvesting, we consider the behavior of ion transportation in a bilayer cylindrical nanochannel with different sized nanopores connecting two reservoirs at different NaCl concentrations.

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Life cycle assessment of salinity gradient energy recovery by reverse electrodialysis in a seawater reverse osmosis desalination plant

Sustainable Energy & Fuels ◽

10.1039/d0se00372g ◽

2020 ◽

Vol 4 (8) ◽

pp. 4273-4284 ◽

Cited By ~ 2

Author(s):

Carolina Tristán ◽

Marta Rumayor ◽

Antonio Dominguez-Ramos ◽

Marcos Fallanza ◽

Raquel Ibáñez ◽

...

Keyword(s):

Life Cycle Assessment ◽

Life Cycle ◽

Energy Recovery ◽

Large Scale ◽

Salinity Gradient ◽

Reverse Electrodialysis ◽

Desalination Plant ◽

Gradient Energy ◽

Seawater Reverse Osmosis ◽

Reverse Osmosis Desalination

LCA of lab-scale and large-scale stand-alone RED stacks and an up-scaled RED system co-located with a SWRO desalination plant.

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Experimental investigation on dye wastewater treatment with reverse electrodialysis reactor powered by salinity gradient energy

Desalination ◽

10.1016/j.desal.2020.114541 ◽

2020 ◽

Vol 495 ◽

pp. 114541 ◽

Cited By ~ 1

Author(s):

Xu Shiming ◽

Leng Qiang ◽

Jin Dongxu ◽

Wu Xi ◽

Xu Zhijie ◽

...

Keyword(s):

Experimental Investigation ◽

Wastewater Treatment ◽

Salinity Gradient ◽

Dye Wastewater ◽

Reverse Electrodialysis ◽

Gradient Energy

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Acid-Base Flow Battery, Based on Reverse Electrodialysis with Bi-Polar Membranes: Stack Experiments

Processes ◽

10.3390/pr8010099 ◽

2020 ◽

Vol 8 (1) ◽

pp. 99 ◽

Cited By ~ 8

Author(s):

Jiabing Xia ◽

Gerhart Eigenberger ◽

Heinrich Strathmann ◽

Ulrich Nieken

Keyword(s):

Single Cell ◽

Cell Number ◽

Open Circuit ◽

Base Flow ◽

Flow Battery ◽

Acid Base ◽

Reverse Electrodialysis ◽

Bipolar Membranes ◽

Acid And Base ◽

Additional Losses

Neutralization of acid and base to produce electricity in the process of reverse electrodialysis with bipolar membranes (REDBP) presents an interesting but until now fairly overlooked flow battery concept. Previously, we presented single-cell experiments, which explain the principle and discuss the potential of this process. In this contribution, we discuss experiments with REDBP stacks at lab scale, consisting of 5 to 20 repeating cell units. They demonstrate that the single-cell results can be extrapolated to respective stacks, although additional losses have to be considered. As in other flow battery stacks, losses by shunt currents through the parallel electrolyte feed/exit lines increases with the number of connected cell units, whereas the relative importance of electrode losses decreases with increasing cell number. Experimental results are presented with 1 mole L−1 acid (HCl) and base (NaOH) for open circuit as well as for charge and discharge with up to 18 mA/cm2 current density. Measures to further increase the efficiency of this novel flow battery concept are discussed.

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