Electrokinetic Power Generation by Forward Osmosis

2012 ◽  
Author(s):  
Kar Cherng Hon ◽  
Chun Yang ◽  
Seow Chay Low
Keyword(s):  
Power Generation ◽  
Salinity Gradient ◽  
Forward Osmosis ◽  
Streaming Potential ◽  
Nacl Solution ◽  
Direct Power ◽  
Concentration Difference ◽  
Permeable Membrane ◽  
Flat Sheet ◽  
Novel Method

In this paper, an innovative direct power generation technique from salinity gradient is proposed and demonstrated. The basis of this novel method encompasses forward osmosis (FO) and electrokinetic (EK) principles. Tapping the concentration difference between seawater and river fresh water, forward osmosis (FO) is utilized to allow for spontaneously transporting water across a semi-permeable membrane. The flow of water is then directed towards array of microchannels in the form of porous medium where power is produced from the electrokinetical streaming potential. Experimentally, NaCl solution and DI water were used to model as seawater and fresh river water, respectively. Both glass and polymer based porous media and commercial flat sheet FO membranes were employed herein. Results show power density could reach the order of 101W/m2. Having features of ease of fabrication, simple configuration and no mechanical moving parts, this method provides a feasible mean to harvest enormous energy from salinity gradient. Thus the proposed technique could contribute greatly to renewable energy and towards sustainable future.

scholarly journals Forward Osmosis Membrane Technology in Wastewater Treatment

2021 ◽  
Author(s):  
Deniz Şahin
Keyword(s):  
Wastewater Treatment ◽  
Forward Osmosis ◽  
Solute Concentration ◽  
Membrane Technology ◽  
Membrane Process ◽  
Water And Wastewater Treatment ◽  
Concentration Difference ◽  
Permeable Membrane ◽  
Treatment Processes ◽  
Space Requirements

In recent times, membrane technology has proven to be a more favorable option in wastewater treatment processes. Membrane technologies are more advantageous than conventional technologies such as efficiency, space requirements, energy, quality of permeate, and technical skills requirements. The forward osmosis (FO) membrane process has been widely applied as one of the promising technologies in water and wastewater treatment. Forward osmosis uses the osmotic pressure difference induced by the solute concentration difference between the feed and draw solutions. The proces requires a semi-permeable membrane which has comparable rejection range in size of pollutants (1 nm and below). This chapter reviews the application of FO membrane process in wastewater treatment. It considers the advantages and the disadvantages of this process.

scholarly journals Novel Thermal Desalination Brine Reject-Sewage Effluent Salinity Gradient for Power Generation and Dilution of Brine Reject

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1756
Author(s):  
Ali Altaee ◽  
Nahawand AlZainati
Keyword(s):  
Power Generation ◽  
Salinity Gradient ◽  
Low Cost ◽  
Water Flux ◽  
Forward Osmosis ◽  
Cellulose Triacetate ◽  
Specific Power ◽  
Sewage Effluent ◽  
Thermal Plant ◽  
Thermal Desalination

Salinity gradient resource presents an essential role for power generated in the process of pressure-retarded osmosis (PRO). Researchers proposed several designs for coupling the PRO process with the desalination plants, particularly reverse osmosis technology for low-cost desalination but there is no study available yet on the utilization of the concentrated brine reject from a thermal desalination plant. This study evaluates the feasibility of power generation in the PRO process using thermal plant brine reject-tertiary sewage effluent (TSE) salinity gradient resource. Power generation in the PRO process was determined for several commercially available FO membranes. Water flux in Oasys Forward Osmosis membrane was more than 31 L/m2h while the average water flux in the Oasys module was 17 L/m2h. The specific power generation was higher in the thin film composite (TFC) membranes compared to the cellulose triacetate (CTA) membranes. The specific power generation for the Oasys membrane was 0.194 kWh/m3, which is 41% of the maximum Gibbs energy of the brine reject-TSE salinity gradient. However, the Hydration Technology Innovation CTA membrane extracted only 0.133 kWh/m3 or 28% of Gibbs free energy of mixing for brine reject-TSE salinity gradient. The study reveals the potential of the brine reject-TSE salinity gradient resource for power generation and the dilution of brine reject.

Developing a HEC/CMC-Reduced Graphene Oxide Hydrogel Nanocomposite for Seawater Desalination

2021 ◽  
Vol 324 ◽  
pp. 173-178
Author(s):  
Terence Tumolva ◽  
Kenneth Carmelo Madamba ◽  
Isabelle Gabrielle Nunag ◽  
Vinz Gabriel Villanueva
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Forward Osmosis ◽  
Antimicrobial Properties ◽  
Water Desalination ◽  
Small Scale ◽  
Cellulose Derivatives ◽  
Permeable Membrane ◽  
Antimicrobial Efficiency ◽  
Reduced Graphene

Current available methods for water desalination are energy intensive, expensive, and not feasible for small-scale applications. As an alternative, hydrogels may be utilized as a draw agent and semi-permeable membrane forward osmosis by acting as both to desalinate water. This study aims to synthesize and characterize hydrogels made from cellulose derivatives and reduced graphene oxide nanofillers in order to desalinate and remove microbes from seawater without requiring a large energy input. The hydrogels are formed by combining carboxymethyl cellulose, hydroxymethyl cellulose, reduced graphene oxide, and water to form a paste which is soaked in a crosslinking solution made of citric acid. Swelling, compression, antimicrobial efficiency and desalination efficiency tests were done. The hydrogel that obtained the highest values has a swelling ratio of 1,447%, compressive strength of 4 bar, desalination efficiency of 30%, and antimicrobial properties.

scholarly journals Module-Scale Simulation of Forward Osmosis Module-Part A: Plate-and-Frame

2016 ◽  
Vol 1 (2) ◽  
pp. 249 ◽  
Author(s):  
Muhammad Roil Bilad
Keyword(s):  
Forward Osmosis ◽  
Mass Conservation ◽  
Feed Solution ◽  
Transfer Model ◽  
Operational Parameters ◽  
Permeable Membrane ◽  
Promising Alternative ◽  
A Value ◽  
Scale Optimization ◽  
Module Performance

In forward osmosis (FO), a semi-permeable membrane separates a concentrated draw and a diluted feed solution. FO has emerges as a promising alternative for various applications. To support further development of FO process, a larger scale optimization is required to accurately envisage the most critical factors to be explored. In this study, we applied a mass-transfer model coupled with the mass conservation and area discretization to simulate the performance of plate-and-frame FO modules (10 sheets of 1x1m). Effects of numerous parameters were simulated: modes, flow orientations (co-, counter- and cross-currents), spacers and spacer properties, membrane parameters and operational parameters. Results show that counter-current flow orientation offers the highest flux with minimum spatial distribution. Module performance can be improved by developing FO membrane through reducing membrane structural (S) parameter and increasing water permeability (A): increasing A-value only significant at low S-value, and vice versa (i.e., for A-value of 1 LMH/atm, S-value must be below 50 µm). Furthermore, inclusion of spacer in the flow channel slightly increases the flux (merely up to 2%). Module performance can also be enhanced by increasing feed flow rate, lowering solute in the feed and increasing solute in the draw solution.

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

2018 ◽  
Vol 20 (10) ◽  
pp. 7295-7302 ◽  
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.

Sign in / Sign up

Export Citation Format

Share Document