Development of novel surface modified poly (vinylidene fluoride ‐ co ‐ hexafluoropropylene) (PVDF ‐ HFP) membrane contactor for CO2 absorption

The ever increasing industrial activities worldwide are the ma in culprits for the greenhouse gases like carbon dioxide (CO 2 ) that cause global warming. Various methods were suggested to curb the production of CO2 , and the latest technology is the utilization of the flexibility of membranes in gas-liquid contactors. The principal aim of this study is to fabricate a surface modified poly (vinylide ne fluoride-co-hexafluoropropylene) (PVDF-HFP) by blending surface modifying macromolecules (SMM) in the polymer dope. Lithium chloride ( LiCl) was employed as pore-forming agent. The surface modified PVDF-HFP showed large pore size, higher effective surface porosity and overall porosity, critical water entry pressure and contact angle than plain PVDF-HFP. Moreoever, the surface modified PVDF-HFP showed a maximum CO 2 flux of 6.74 x 10 -4 mol/m 2 .s, which was nearly 38% higher than that of the control plain PVDF-HFP

PVDF/CaCO3 composite hollow fiber membrane for CO2 absorption in gas-liquid membrane contactor

Porous hydrophobic polyvinylidene fluoride (PVDF) composite hollow fiber membranes were fabricated via phase inversion method by embedding different amounts of hydrophobic calcium carbonate (CaCO3) nano-particles in the polymer matrix. The effects of nano-particle loadings on the morphology, structure and performance of the spun membranes in gas-liquid contactors were investigated. The incorporation of hydrophobic nano-particles into the polymer network enabled the formation of more abundant and narrower finger-like pores in the composite membranes compared to plain PVDF membrane. Moreover, the addition of nano-particles enhanced the surface roughness, permeation rate, porosity and wettability resistance of the composite membranes. CO2 absorption performance of the fabricated membranes was evaluated via a gas-liquid membrane contactor system. The CO2 flux was improved to some extent by increasing the mixing ratio of CaCO3. Peak absorption performance of 1.52 × 10-3 mol m-2 s-1 at 300 ml/min absorbent flow rate was achieved when 20/100 weight ratio of CaCO3/PVDF was employed. However, further increase of the ratio resulted in a composite membrane with lower absorption performance than the other composite membranes. Moreover, a long-term stability study of the composite membrane with the best CO2 absorption flux showed no decline in performance in the initial 210 h of operation, indicating that the membrane possesses high potential for gas-liquid contactor applications