PDF Publication Title:
Text from PDF Page: 058
accurate estimations can be made by experiments [199], or by models, e.g. numerical simulations solving the Laplace equation for the electric potential field [6] decoupled from the concentration field. In addition, also profiled membranes can be simulated, provided the IEM can be treated as a homogeneous resistive material with a uniform electric conductivity. However, in order to reduce the computational effort, such simulations can be restricted to a small number of cases in order to verify/calibrate approximate expressions, more suitable for fast-running models. For example, in the case of a woven spacer with a pitch-to-height ratio of 2 the channel resistance was shown to be inversely proportional to the porosity with a good approximation [6]. 5.2.2 Mass balances and transport across membranes Eq. (28) and all the related equations for the calculation of electric variables can be expressed as functions of the x coordinate along the flow direction. Mass balances and transport equations across the membranes allow the variation of concentrations and flow rates along the flow direction to be computed, thus providing all the information needed fully to characterise the system along its entire length [6, 141, 199, 254, 297]. Following an approach similar to the Nernst–Planck one, ions transport within the membrane can be expressed as the sum of an Ohmic conduction flux and a diffusion flux (see Section 4.1). Therefore, the expressions for ions fluxes across the two IEMs of an ED channel can be generalized for monovalent salts as [6, 141, 199, 254]: 𝐽(𝑥) = [𝑡 − (1 − 𝑡)] 𝑖(𝑥) (32) 𝐹 𝐽(𝑥)= 𝐷[𝐶(𝑥)−𝐶(𝑥)]+𝐷[𝐶(𝑥)−𝐶(𝑥)] (33) h h 𝐽(𝑥) = 𝐽(𝑥) + 𝐽(𝑥) (34) where 𝑡 and 𝑡 are the transport numbers of the counter-ions inside the IEMs, 𝐷 and 𝐷 are the salt (diffusion) permeability coefficients through the IEMs, h and h are the thicknesses of IEMs, 𝐶, 𝐶, 𝐶 and 𝐶 are the electrolyte concentrations at the various IEM-solution interfaces (solution side) [6, 254] and i is the electric current density. Some models simplify eq. (33) by using only one proportionality factor for both IEMs [141, 199, 254] and/or the bulk concentrations instead of those at the interface [141, 199]. The Ohmic conduction is taken as positive, while the diffusion term that contributes to the total flux must be taken with the suitable sign in eq. (34), i.e. in ED channels the diffusion has to be considered negative, since conduction and diffusion are opposite. The Ohmic conduction is the most important as it is directly linked to the ionic current, while the diffusive flux is the result of the non-ideal membrane permselectivity. Therefore, the influence of diffusion through the IEMs on the overall process strongly depends on the specific membrane [315]. 58PDF Image | Electrodialysis for water desalination
PDF Search Title:
Electrodialysis for water desalinationOriginal File Name Searched:
Review_ED-self-archived.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)