Power from salinity gradients

Wick, Gerald L.

doi:10.1016/0360-5442(78)90059-2

Cited by 104 publications

(53 citation statements)

References 9 publications

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“…Recent developments in materials science have also allowed the use of FO in controlled drug release in the body [24][25][26][27]. Pressure-retarded osmosis (PRO), a closely related process, has been tested and evaluated since the 1960s as a potential process for power generation [28][29][30][31][32][33][34][35][36][37][38][39]. PRO uses the osmotic pressure difference between seawater, or concentrated brine, and fresh water to pressurize the saline stream, thereby converting the osmotic pressure of seawater into a hydrostatic pressure that can be used to produce electricity.…”

Section: Introductionmentioning

confidence: 99%

Forward osmosis: Principles, applications, and recent developments

Cath

Childress

Elimelech

2006

Journal of Membrane Science

2,267

1,529

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Section: Introductionmentioning

confidence: 99%

Forward osmosis: Principles, applications, and recent developments

Cath

Childress

Elimelech

2006

Journal of Membrane Science

2,267

1,529

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“…By using a small RED stack, energy consumption for water pumping was negligible compared to the produced energy as H 2 . Because practical applications of RED have been limited due to the need for stacks with hundreds ion-exchange membranes, this unique MREC process could be used to more efficiently produce H 2 from an estimated 1.7 TW of global salinity driven energy (18).…”

mentioning

confidence: 99%

Hydrogen production from inexhaustible supplies of fresh and salt water using microbial reverse-electrodialysis electrolysis cells

Kim

Logan

2011

Proc. Natl. Acad. Sci. U.S.A.

167

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There is a tremendous source of entropic energy available from the salinity difference between river water and seawater, but this energy has yet to be efficiently captured and stored. Here we demonstrate that H 2 can be produced in a single process by capturing the salinity driven energy along with organic matter degradation using exoelectrogenic bacteria. Only five pairs of seawater and river water cells were sandwiched between an anode, containing exoelectrogenic bacteria, and a cathode, forming a microbial reverse-electrodialysis electrolysis cell. Exoelectrogens added an electrical potential from acetate oxidation and reduced the anode overpotential, while the reverse electrodialysis stack contributed 0.5-0.6 V at a salinity ratio (seawater:river water) of 50. The H 2 production rate increased from 0.8 to 1.6 m 3 -H 2 ∕m 3 -anolyte/day for seawater and river water flow rates ranging from 0.1 to 0.8 mL∕ min. H 2 recovery, the ratio of electrons used for H 2 evolution to electrons released by substrate oxidation, ranged from 72% to 86%. Energy efficiencies, calculated from changes in salinities and the loss of organic matter, were 58% to 64%. By using a relatively small reverse electrodialysis stack (11 membranes), only ∼1% of the produced energy was needed for pumping water. Although Pt was used on the cathode in these tests, additional tests with a nonprecious metal catalyst (MoS 2 ) demonstrated H 2 production at a rate of 0.8 m 3 ∕m 3 ∕d and an energy efficiency of 51%. These results show that pure H 2 gas can efficiently be produced from virtually limitless supplies of seawater and river water, and biodegradable organic matter.electrohydrogenesis | microbial electrolysis cell | microbial fuel cell | renewable energy | sustainable energy E xoelectrogenic bacteria oxidize organic matter and can transfer electrons to electrically conductive materials such as graphite or metal, making it possible to convert waste organic matter into useful energy. In microbial fuel cells (MFCs), exoelectrogens on the anode, coupled with oxygen reduction at the cathode, can generate a potential as large as ∼0.8 V (open circuit; pH 7; 0.2 atm O 2 ), although less voltage (∼0.23 to 0.5 V) is generated in practice (1). Exoelectrogens can also be used to drive electrochemical H 2 production in a microbial electrolysis cell (MEC) (2, 3). However, the potential generated by substrate oxidation (−0.30 V vs. Standard Hydrogen Electrode; 1 g∕L acetate; pH 7) is not sufficient to drive H 2 evolution (−0.41 V vs. Standard Hydrogen Electrode at pH 7) (1). Thus, additional energy (∼0.11 V in theory) is needed to overcome this thermodynamic threshold, and an external voltage of >0.4 V is typically applied to MECs (4). This additional energy could be provided by a renewable source of energy, such as solar (5), wind, or waste organic matter (6). However, no method has yet been developed to directly achieve H 2 production in one process without an external voltage supply.Reverse electrodialysis (RED) holds great promise as a method for generat...

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“…The virtual RED voltage (the voltage without the losses at the electrodes) is obtained from a pair of reference electrodes in the electrode compartments near to the outer membranes. Weinstein and Leitz [16], Wick [17], Loeb [18], Metha [19] and Suda et al [20] reported such systems. At the cathode hydrogen is evolved and at the anode chlorine is evolved if a NaCl solution (or sea water) is used in the electrode compartments.…”

Section: Overviewmentioning

confidence: 99%

“…has to diffuse from the solution to the Ag surface. This system was described by Audinos [16,17] and included as system nr. 3 in Table 1.…”

Section: Electrical Properties Of the Electrode Systemmentioning

confidence: 99%

Reverse electrodialysis: evaluation of suitable electrode systems

Veerman

Saakes²,

Metz³

et al. 2010

J Appl Electrochem

238

188

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Reverse electrodialysis (RED) is a method for directly extracting electrical energy from salinity gradients, especially from sea and river water. For the commercial implementation of RED, the electrode system is a key component. In this paper, novel electrode systems for RED were compared with existing systems on safety, health, environment, technical feasibility and economics. Systems with inert DSA-type electrodes and a NaCl-HCl supporting electrolyte with the reversible Fe 2? /Fe 3? redox couple or the [Fe(CN) 6 ] 4-/Fe(CN) 6 ] 3-couple achieved the highest ranking. Improvements of the electrode system are also discussed like the use of special stable metal electrodes, graphite electrodes, other reversible redox couples, capacitive electrodes and electrolytes with carbon particles.

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Power from salinity gradients

Cited by 104 publications

References 9 publications

Forward osmosis: Principles, applications, and recent developments

Forward osmosis: Principles, applications, and recent developments

Hydrogen production from inexhaustible supplies of fresh and salt water using microbial reverse-electrodialysis electrolysis cells

Reverse electrodialysis: evaluation of suitable electrode systems

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