A Similarity Principle-Based Multiscale Electrodialysis Desalination Unification With Multi-Physical Parameter...

Area of Science:

• Multiscale modeling
• Electrochemical engineering
• Separation processes

Background:

• Electrodialysis (ED) is a key electricity-driven seawater desalination method.
• Current research often focuses on material design and device structure, neglecting the process's complexity.
• A unified approach is needed to understand and optimize the multiscale, multiphysical ED process.

Purpose of the Study:

• To develop a similarity principle-based multiscale model for electrodialysis.
• To unify the complex, high-dimensional parameters governing ED into dimensionless variables.
• To identify dominant parameters influencing seawater desalination rate.

Main Methods:

• Non-dimensionalization of Poisson-Nernst-Planck equations for mesoscopic and macroscopic models.
• Development of dimensionless variables representing ion absorption, transport, nanopore, space charge, and driving force characteristics.
• Application of the Taguchi method for multi-physical sensitivity analysis.

Main Results:

• The mesoscopic ED model was unified using 3 dimensionless variables, and the macroscopic model using 6.
• The similarity principle was validated, showing minimal variation in dimensionless cation-anion difference (0.25%) and outlet Na+ concentration (0.05%).
• Seawater temperature (39.74%) was identified as the most significant parameter affecting desalination rate, followed by initial ion concentration and applied electric potential.

Conclusions:

• The developed multiscale model provides a unified framework for understanding ED ion migration.
• Dimensionless variables simplify ED process analysis and facilitate optimization.
• The findings establish a theoretical basis for experimental correlations and AI-driven predictions in ED desalination.