Preparation of microporous PVDF hollow fiber membrane contactors for CO2 stripping from diethanolamine solution

Abstract

Microporous polyvinylidene fluoride (PVDF) hollow fiber membranes were fabricated via a wet-spinning process. The prepared fibers were characterized in terms of contact angle, gas permeability, wetting pressure and morphology. CO 2 stripping from preloaded aqueous diethanolamine solution was conducted through the gas-liquid membrane contactors. The effects of lithium chloride (LiCl) concentration on the membrane properties and CO 2 stripping performance were investigated. The addition of different LiCl concentration resulted in a less finger-like structure, with highly effective surface porosity and high wetting pressure. Conversely, N 2 permeability, contact angle value and membrane pore size were reduced as the concentration of the additives were increased. For stripping flux performance, membrane with 5wt% LiCl demonstrated the highest flux of 1.61×10 -2mol/m 2s at 110ml/min of the liquid flow rate. It was found that the membrane with less finger-like structure and higher effective surface porosity exhibited higher stripping efficiency. These results suggest that developed membrane structure can be an alternative for the CO 2 stripping through gas-liquid membrane contactors.