Enhancing mechanistic models with neural differential equations to predict electrodialysis fouling

Portable Seawater Desalination System for Generating Drinkable Water in Remote Locations

“…The multistage process is widely applied in desalination to avoid a large entropy generation and significant thermal disequilibrium in a single-stage process. − In particular, entropy generation (and excessive energy consumption) in electromembrane processes (ED and ICP) increases in a nonlinear fashion with current, due to new current carrier generation, membrane discharging by the thicker depletion layer, trans-membrane concentration difference leading to osmosis and diffusion, and electro-osmosis. − It is therefore challenging to optimize the staging configuration toward the proper trade-off between productivity (needed for a small-size membrane) and energy efficiency (needed for a small-size battery) ,, without engineering models for unit processes. Several physics-based models, solving Nernst–Planck–Poisson and Navier–Stokes equations concurrently, have already been developed to describe ion transport mechanisms of a conventional electromembrane process (i.e., ED); however, they are limited to operating in an ohmic regime where voltage drop and ion transport respond linearly with changes in current. , Also, simulation-based surrogate models based on machine learning methods were applied to predict ED processes, treating brackish water (2–10 mM of salt) for which ion-exchange membranes could retain their ideal permselectivities. , However, these earlier models for the electromembrane process are not adequate for our purpose, where small-size electromembranes push the operating current beyond the Ohmic regime.…”

“…34,38 Also, simulation-based surrogate models based on machine learning methods were applied to predict ED processes, treating brackish water (2−10 mM of salt) for which ion-exchange membranes could retain their ideal permselectivities. 39,40 However, these earlier models for the electromembrane process are not adequate for our purpose, where small-size electromembranes push the operating current beyond the Ohmic regime.…”

A model-based analysis of electrodialysis fouling during pulsed electric field operation

“…It is plausible that similar effects occur during ED where the absence (or reduction) of the external electric field during the passive cycles relaxes the fouling layer making it more susceptible to being sheared off. De Jaegher et al [63] discusses the force balance on a fouling component during ED and pressure-driven membrane filtration and foulant/membrane interactions and the electric field is proposed as the prominent external driving force that leads to fouling. In contrast, liquid shear is proposed as the prominent driving force that counter fouling.…”

A Review on Ion-Exchange Membranes Fouling during Electrodialysis Process in Food Industry, Part 2: Influence on Transport Properties and Electrochemical Characteristics, Cleaning and Its Consequences

“…Many of the researchers note that fouling leads to a decrease in the current efficiency (η) in ED of liquid media (including in the food industry) [108,[111][112][113][114][115]. It is known [116,117] that the current efficiency of the target component (for definiteness, the salt anion) is determined by the difference between the effective transport numbers of this anion through AEM (as a counterion) and through CEM (as a co-ion), which form the ED desalination channel.…”