Fabrication of ZIF-8/Cellulose Acetate Mixed Matrix Membrane for CO2/CH4 Separation

With the drastic change of global warming attributed by the emission of CO2, removal
of CO2 has become very important in the sweetening process of natural gas.
Development of membrane technology has been advantageous towards the
applications in gas separation. This research aims to synthesize ZIF-8 nano-crystals
and fabricate a series of mixed matrix membranes (MMMs) by incorporating different
loadings of ZIF-8 nano-fillers into cellulose acetate (CA) polymer matrix. The effect
of different loading (5wt%, 10wt%, 15wt% and 20wt%) of ZIF-8 in MMM towards
the CO2/CH4 gas separation was tested with pure gas permeation test. The optimum
loading of ZIF-8 in MMM which resulted the best CO2/CH4 separation performance
was 5wt% of ZIF-8 loading. Results showed that permeability of CO2 and CH4
increased from 12.19 barrer and 2.16 barrer in pure CA membrane to 245.75 barrer
and 4.65 barrer in the MMM loaded with 5wt% of ZIF-8. The CO2/CH4 selectivity of
ZIF-8/CA MMM reached up to 52.85 barrer from 5.63 barrer in pure CA membrane.