A computational study on molecular transport mechanisms and models for alcohol recovery by polymer pervaporation membranes

TY - JOUR

T1 - A computational study on molecular transport mechanisms and models for alcohol recovery by polymer pervaporation membranes

AU - Li, Shen Hui

AU - Xu, Li Hao

AU - Qi, Hao

AU - Feng, Ying Nan

AU - Zhao, Zhi Ping

N1 - Publisher Copyright: © 2026 American Institute of Chemical Engineers.

PY - 2026/6

Y1 - 2026/6

N2 - Model development for bio-alcohol recovery via pervaporation (PV) membranes has been hindered by insufficient molecular-level transport insights. We conducted molecular dynamics simulations to unravel the transport mechanism of solvent (water and alcohol) molecules in polymer membranes. For membranes with different hydrophobicity, alcohol concentrations at both solution-membrane and vapor–liquid interfaces were similar and approximated the activity in aqueous solution. We developed a thermodynamic cycle method for calculating interaction parameters and applied Flory-Huggins theory to quantify the solubility of solvent molecules. In dilute alcohol solutions (≤5 wt%), low solubility promotes molecular-level dispersion of solvent molecules in membranes, making diffusion coefficients nearly solubility independent. Based on these molecular-level insights, the factors affecting the separation factor/relative volatility of PV/distillation processes were quantified using proposed coefficients. These coefficients provide an intuitive understanding of why the separation factor of various polymer membranes is higher or lower than the relative volatility.

AB - Model development for bio-alcohol recovery via pervaporation (PV) membranes has been hindered by insufficient molecular-level transport insights. We conducted molecular dynamics simulations to unravel the transport mechanism of solvent (water and alcohol) molecules in polymer membranes. For membranes with different hydrophobicity, alcohol concentrations at both solution-membrane and vapor–liquid interfaces were similar and approximated the activity in aqueous solution. We developed a thermodynamic cycle method for calculating interaction parameters and applied Flory-Huggins theory to quantify the solubility of solvent molecules. In dilute alcohol solutions (≤5 wt%), low solubility promotes molecular-level dispersion of solvent molecules in membranes, making diffusion coefficients nearly solubility independent. Based on these molecular-level insights, the factors affecting the separation factor/relative volatility of PV/distillation processes were quantified using proposed coefficients. These coefficients provide an intuitive understanding of why the separation factor of various polymer membranes is higher or lower than the relative volatility.

KW - bio-alcohol recovery

KW - mass transfer model

KW - molecular dynamics

KW - pervaporation

KW - polymer membrane

UR - https://www.scopus.com/pages/publications/105032243124

U2 - 10.1002/aic.70346

DO - 10.1002/aic.70346

M3 - Article

AN - SCOPUS:105032243124

SN - 0001-1541

VL - 72

JO - AIChE Journal

JF - AIChE Journal

IS - 6

M1 - e70346

ER -