Experimental and modeling investigation of ultrafine polyvinylidene fluoride hollow fiber membrane module for recovery of lactic acid from aqueous solutions

Abstract

AbstractThis study investigated the aqueous lactic acid extraction process using indigenous ultrafine polyvinylidene fluoride (PVDF) hollow fiber membrane contactor. Ultrafine PVDF hollow fibers with tighter pore structure were produced by wet spinning technique and fabricated in‐house with an epoxy resin. A kinetic study was performed by varying acid concentrations ranging from 60 to 1320 mol/m3 in an aqueous phase and 210–620 mol/m3 tri‐n‐octylamine (TOA) concentration in 1‐octanol diluent. The solutions were allowed to flow countercurrently using peristaltic pumps at constant aqueous and organic flow velocity of 0.006 and 0.005 m/s, respectively. A PRO/II simulation of the membrane contactor system was carried out to validate experimental results. The study showed a maximum acid extraction of 88 ± 0.1% for initial acid and amine concentrations of 250 and 620 mol/m3, respectively, which corresponds to a high KD value of 11.5 which is larger than the value found from PRO/II simulation for direct mixing of the aqueous and organic phases which demonstrates the merit of the membrane contactor. The exploratory study on kinetics has helped in understanding the mass transfer phenomena of the solute across the membrane. In addition, membrane characterization was done to investigate the surface and cross‐sectional morphologies and mechanical strength properties.