Polyvinylidene Fluoride Hollow Fiber Membrane Contactor Incorporating Surface Modifying Macromolecule for Carbon Dioxide Stripping from Water

Porous surface modified polyvinylidene ï ‚uoride (PVDF) hollow fiber membranes are fabricated through a dry-wet phased inversion process. Surface modifying macromolecules (SMM) (۱ wt. %) are used as additives in the spinning dope. The performance of the surface modified membrane in contactor application for CO۲ stripping from water is assessed through the fabricated gas–liquid membrane contactor modules. It is found that the liquid phase resistance is dominant in the stripping flux experiments. The results indicate that the surface modified PVDF membrane out performs control PVDF membrane. By applying surface modified membrane in a CO۲ stripping process at the liquid flow rate of ۲۰۰ ml.min-۱, the maximum CO۲ stripping flux and efficiency of ۱.۷۸ × ۱۰-۳ and ۶۵ % are achieved, respectively. Enhancement of gas flow rate increased the CO۲ desorption flux, while this changing is negligible. By increasing the liquid temperature from ۸۰ to ۹۰ oC, the CO۲ stripping flux increases from ۱.۷۸×۱۰−۳ to ۲.۱۸ ×۱۰−۳ mol.m-۲.s-۱ at ۲۰۰ ml.min-۱ liquid velocity.  Consequently, the liquid phase temperature has a significant effect on the stripping flux in membrane contactor application. In a long-term stability study, CO۲ stripping flux decreases about ۱۶.۴ % by using surface modified PVDF membrane during ۱۳۰ h operation.

Keywords:

PVDF Hollow Fiber Membrane , Surface Modifying Macromolecule (SMM) , Membrane Contactor , CO۲ Stripping