Study on CO2 removal in air by hydrogel membranes

In this paper, hydrogel membrane techniques used for CO2 removal from air were introduced. Firstly, the PVDF hollow fibers were prepared by dry-jet wet-spinning phase-inversion process, then membrane module was made of them as a CO2 removal equipment. PVDF hollow fiber membranes modified by alkali, was casted by PVA hydrogel on its surface and PVDF-PVA hydrogel membranes were prepared. The effects of the concentration of monomer (PVA) and cross-linker (glutaraldehyde) on the swelling ability of the gel of hydrogel membranes were investigated. For carbonate hydrogel membrane, CO2 concentration from 1.3% to 0.6% in feed gas could be decreased to 0.9– 0.4% at the outlet at 25°C. For an immobilized enzyme hydrogel membrane, CO2 concentration from 0.7% to 0.5% in feed gas could be decreased 20% at 25°C.

In conclusion, both of the modules of PVDFPVA hydrogel membrane with can be used for CO2 removal from air. However, for the ability of CO2 transport through the hydrogel membrane, PVDF-PVA hydrogel with carbonate groups is much faster than the PVDF-PVA hydrogel membrane with immobilized enzyme.