(164h) Modeling of Nanofiltration Membrane Separation for Aqueous Organic Acid Multi Component Mixtures

Nanofiltration membrane separation presents a cost-effective and energy-efficient strategy for selectively removing organic acids from biomass fermentation broths. To advance process development in this area, rigorous thermodynamic modeling is essential for reducing reliance on expensive and labor-intensive experimental methods. A thorough understanding of the fundamental physical mechanisms governing separation enables the systematic application of this unconventional yet efficient technique to address real-world challenges.

This work presents a robust thermodynamic modeling framework to elucidate the separation behavior of commercially available nanofiltration membranes for multicomponent aqueous organic acid systems. Building upon the classical solution-diffusion model, the proposed approach integrates detailed aqueous-phase organic acid solution chemistry, non-ideal solution behavior, and membrane-solution interactions. The model accurately describes single-component separation and delivers precise predictions for binary and ternary systems across a broad range of operational conditions, including feed pH (3–10), acid concentrations (0.2–0.6 mmol/L), applied pressures (3.44–27.57 bar), and a temperature of 298.15 K.

By capturing the complexities of organic acid nanofiltration, this model provides critical insights into process performance and efficiency. The proposed framework serves as a valuable theoretical foundation for the design and optimization of economically viable, energy-efficient nanofiltration processes for organic acid recovery, with significant potential for industrial-scale biomass fermentation applications.