PDF Publication Title:
Text from PDF Page: 044
Membranes 2020, 10, 221 44 of 72 Figure 23. Principle of reverse ED. CEM: cation-exchange membrane; AEM: anion-exchange membrane; HSS: high-salinity stream; LSS: low-salinity stream. Similarly to other electrodialytic processes, RED’s early inception (1954) led to slow developments correlated with the inadequate performances of membrane materials at this time. Current membranes exhibit higher conductivity and improved selectivity allowing to reach power densities in the range of 2–10 W/m2 at lab scale [258,259]. Flow dynamics have a substantial impact on power density results leading to the development of turbulence-inducing woven spacers [260,261]. Furthermore, membrane permselectivity has proven to be another critical factor for RED, since divalent cations can greatly affect the power capacity causing an efficiency drop and increasing the membrane resistance by possible scaling [261–263]. The development of monovalent permselective membranes based on charge repulsion or steric exclusion as well as the better understanding of scaling mechanisms, especially in relation to the pH, paves the way toward improved more viable performances [85,263–266]. Yet, RED applications on close systems relying on artificially-prepared streams of monovalent ions still outperform by far equipment implemented in natural environments such as estuaries for which organic fouling also must be considered [257,267–269]. Due to the permselectivity, scaling and fouling issues, when looking at implementations in “real” conditions, power densities range from –0.01 to 0.65 W/m2 for treatments of 1–3 months [265]. Hence, Tedesco et al. [264] studied the performances of REAPower, a pioneer RED pilot plant in Italy with a 1 kW overall plant capacity objective which demonstrated 700 W with artificial NaCl streams vs. 330 W with natural brine and brackish water. Bolstered by 500 cell pairs for a total of about 100 m2, the plant achieved a power density of about 0.8 W/m2 over 5 months with real streams [259]. Another pilot plant was established in The Netherlands (Blue Energy project) aiming for an overall capacity of 50 kW while the next stage would be a demo pilot up to 2 MW [270]. More recently, a pilot plant in South Korea exhibiting 1000 cell pairs for a total membrane surface of 250 m2 managed a power density of 0.38 W/m2 using seawater and wastewaters [262]. Gómez-Coma et al. [271] implemented a 20-day RED experiment with power densities up to 1.4 W/m2. Although carried out with a small-scale RED, natural sea water and reclaimed water from wastewater treatment plants were used as feeds with no fouling. Despite these encouraging results, the economic viability of RED is still precarious, largely due to membrane cost and maintenance as well as the low current densities attained. Power densities greater than 2 W/m2 were evaluated as economically suitable for capturing SGP [263,272]. However, more profitable strategies are currently studied by combining RED with sea water desalination units for better eco-efficiency (see Section 5.1.3). In addition, efforts are being made to develop new reverse electrodialytic ways to produce and store SGP [257]. Even though they provide better flux dynamics by promoting turbulence, spacers are known to be more responsible for organic fouling issues than membranes [269]. RED with membrane-electrode assembly (MEA) was developed as a non-spacer technology to lower compartment resistance andPDF Image | Electrodialytic Processes
PDF Search Title:
Electrodialytic ProcessesOriginal File Name Searched:
membranes-10-00221.pdfDIY PDF Search: Google It | Yahoo | Bing
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
IT XR Project Redstone NFT Available for Sale: NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Be part of the future with this NFT. Can be bought and sold but only one design NFT exists. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Turbine IT XR Project Redstone Design: NFT for sale... NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Includes all rights to this turbine design, including license for Fluid Handling Block I and II for the turbine assembly and housing. The NFT includes the blueprints (cad/cam), revenue streams, and all future development of the IT XR Project Redstone... More Info
Infinity Turbine ROT Radial Outflow Turbine 24 Design and Worldwide Rights: NFT for sale... NFT for the ROT 24 energy turbine. Be part of the future with this NFT. This design can be bought and sold but only one design NFT exists. You may manufacture the unit, or get the revenues from its sale from Infinity Turbine. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Supercritical CO2 10 Liter Extractor Design and Worldwide Rights: The Infinity Supercritical 10L CO2 extractor is for botanical oil extraction, which is rich in terpenes and can produce shelf ready full spectrum oil. With over 5 years of development, this industry leader mature extractor machine has been sold since 2015 and is part of many profitable businesses. The process can also be used for electrowinning, e-waste recycling, and lithium battery recycling, gold mining electronic wastes, precious metals. CO2 can also be used in a reverse fuel cell with nafion to make a gas-to-liquids fuel, such as methanol, ethanol and butanol or ethylene. Supercritical CO2 has also been used for treating nafion to make it more effective catalyst. This NFT is for the purchase of worldwide rights which includes the design. More Info
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
Infinity Turbine Products: Special for this month, any plans are $10,000 for complete Cad/Cam blueprints. License is for one build. Try before you buy a production license. May pay by Bitcoin or other Crypto. Products Page... More Info
CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com (Standard Web Page)