(401ak) A Study on the Modification of PVDF Membranes for Enhanced CO2/CH4 Gas Separation Performance

This study explores the effect of glycerol-impregnation on the structural, compositional, and gas separation performance of PVDF membranes for CO₂/CH₄ separation. The variation of glycerol loading (0-70 wt.%) caused a significant morphological transition in the architectures of the resulting composite as verified by SEM. The EDS analysis revealed higher oxygen and lower fluorine content with glycerol loading, which confirmed glycerol retention and PVDF–glycerol interactions that enabled phase reorganization and densification. Permeation studies of gas showed a permeability–selectivity trade-off. While CH₄ and CO₂ permeabilities fell as a result of reduced pore volume and tighter packing of the chains with glycerol loading, CO₂/CH₄ selectivity increased significantly. The study confirmed the permeability–selectivity trade-off reported by Robeson, as glycerol modification significantly influenced membrane performance. At 30 wt.% glycerol, CO₂ permeability dropped by 99.3% with a 20.83% increase in selectivity. At 50 wt.%, a favorable balance was observed with a 14.19% permeability reduction and a 36.95% increase in selectivity. Further increase to 70 wt.% led to a 61.11% decline in permeability and a 23.02% improvement in selectivity. This proves that physical modification through the use of glycerol presents an opportunity for tuning the performance of the membrane without chemical crosslinking. The results show great promise for energy-efficient gas separation applications such as natural gas upgrading and CO₂ capture. Future work should be directed towards the evaluation of long-term performance and mixed-matrix composite of PVDF/Glycerol to improve the separation process.

Keywords: Glycerol Modification; Membrane Separation; Natural Gas Upgrading; CO2/CH4

Separation; CO2 Capture