Enhanced energy recovery using a cascaded reverse electrodialysis stack for salinity gradient power generation
| Autor: | Hanki Kim, Eunjin Jwa, Namjo Jeong, Kyo-Sik Hwang, Joo-Youn Nam, Hyunji Eom |
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| Rok vydání: | 2021 |
| Předmět: |
Salinity
Environmental Engineering Materials science 0208 environmental biotechnology 02 engineering and technology 010501 environmental sciences 01 natural sciences Stack (abstract data type) Electricity Reversed electrodialysis Osmotic power Specific energy Process engineering Waste Management and Disposal Electrodes 0105 earth and related environmental sciences Water Science and Technology Civil and Structural Engineering Power density Energy recovery business.industry Ecological Modeling Electrodialysis Pollution 020801 environmental engineering Anode business |
| Zdroj: | Water research. 200 |
| ISSN: | 1879-2448 |
| Popis: | Despite significant advances in the field applications of reserve electrodialysis (RED) to produce salinity gradient power, net energy production remains an issue owing to limitations such as high energy requirement for high flow rates of feed solutions, and severe fouling and pressure build up when thin spacers are used. Therefore, to maximize the performance and efficiency of energy harvesting in the RED, a cascaded RED stack, with multiple stages between the anode and cathode electrodes, was investigated. In cascaded stacks, 100-cell paired stacks were divided into several stages, so the feed water flowed into the first stage, and the effluent from the first stage was then reused in the next stages. This cascaded stack could overcome the typical drawbacks of RED (large amount of feed water required, intensive pumping energy, and low net energy production). Although 25% of the feed water volume was used in the 4-stage cascaded stack (100-cell-pairs) compared to the conventional stack (100-cell-pairs with a parallel flow operation), much more energy was produced with the 4-stage cascaded stack. The net power density and net specific energy with the 4-stage cascaded stack were the highest at 0.5 cm/s (0.48 W/m2) and 0.25 cm/s (0.06 kWh/m3), respectively. This is very promising for the practical application of RED since feed water volumes can be greatly reduced, which could reduce the burden on the feed water pretreatment step. Consequently, we can build a compact RED plant with smaller pretreatment processes and fewer RED unit stacks. |
| Databáze: | OpenAIRE |
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