CO2 Absorption with NaOH Solution through the Porous PVDF Hollow Fibre Membrane Contactor

Abstract

In this study, porous hydrophobic polyvinylidene fluoride (PVDF) hollow fiber membranes were fabricated via a wet phase inversion process. In order to improve the phase inversion rate and provide porous membranes, 4 wt.% lithium chloride (LiCl) was used in the spinning dope. The prepared membrane morphology was studied using field emission scanning electron microscopy (FESEM). Chemical CO₂absorption by NaOH solution (1M) was conducted through the PVDF hollow fiber membrane contactor. The effect of the main operating condition such as absorbent temperature, CO₂ pressure and absorbent flow rate on the performance of CO₂ absorption was investigated. From FESEM examination, the membrane possesses an almost sponge–like structure with ultra thin skin layer. Results of CO₂absorption test showed that by increasing the absorbent flow rate the CO₂ flux increased which confirmed the existence of liquid side mass transfer resistance. It was found that by increasing the absorbent temperature the CO₂ flux considerably improved. Meanwhile, the effect of CO₂ pressure on the absorption rate was insignificant. Therefore, it can be concluded that by applying a porous hydrophobic membrane with improved structure and optimizing the operating conditions, high CO₂ removal efficiency can be achieved through gas–liquid membrane contactors