Abstract:
In recent years, there has been an increasing demand for efficient separation
technologies for CO2/CH4 gas mixtures, particularly in the natural gas processing
industry. The separation of CO2 from CH4 is crucial to produce natural gas with a high
heating value and reduced greenhouse gas emissions. Due to their low energy
requirements, scalability, and affordability, membrane-based gas separation
technologies have become a possible replacement for conventional separation
techniques. In gas separation applications, mixed matrix membranes (MMMs), which
incorporate the benefits of both polymers and inorganic materials, have gained a lot of
interest. In this study, 2D graphitic carbon nitride nanosheets (g-C3N4) were added to
the polymer matrix to enhance the performance of cellulose acetate MMMs for
CO2/CH4 gas separation. The solution casting process was used to create CA based
MMMs with different g-C3N4 loadings like 0.5,1.0 and 1.5 wt% using tetrahydrofuran
(THF) as solvent. FTIR, XRD, SEM, UTM and permeation studies were used to
characterize the produced MMMs. Incorporation of GCN into CA polymer matrix
enhances its Thermal and Mechanical stability. It was found that GCN based CA
MMMs give better CO2/CH4 selectivity of 2.73 at a GCN loading of 0.5 wt% with CO2
permeability of 78 Barrer at 2 bars. A more compact and dense structure could be seen
in the SEM images, FTIR confirms the presence of functional groups, XRD confirms
the presence of GCN nanosheets in the MMMs. Moreover, maximum tensile strength
of 81.66 MPa was shown by 0.5 wt% g-C3N4/CA mixed matrix membrane. In this
study, results suggest that addition of GCN into CA polymer matrix enhances CO2 gas
permeability having less impact on CO2/CH4 selectivity, further research should be
carried out to improve selectivity of these membranes.
