The Performance of PPOdm-CNF Mixed Matrix Membrane for CO2/CH4 Separation

Abstract

Mixed Matrix Membrane (MMM) is one of the most promising candidate among the available gas separation application for CO₂/CH₄ separation in natural gas industries. However, the fabrication of a defect-free MMM remains a challenge. For this work, a novel MMM was developed by incorporating carbon nanofibers (CNF) at different weight loadings into poly (2, 6-dimethyl-1, 4-pheneylene oxide) (PPOdm) polymer matrix via dry-phase inversion technique. CNF was purified with hydrogen peroxide prior to
membrane fabrication. Approximately 178 % increment in the CO₂ permeability were attained at 3 wt% of CNF loading whereas the CO₂/CH₄ selectivity were increased by 53% compared to pristine PPOdm polymeric membrane. The smooth wall of CNF coupled with its larger pore diameter acted as a pathway and renders high gas permeability values. PPO_dm – 3 wt% CNF MMM exhibits improved morphology with no significant filler agglomeration on the polymer matrix. The TGA and DSC analysis showed that at 3 wt%
of CNF loading, the thermal stability of the polymer chains was enhanced in which higher decomposition (T_d = 425 ºC) and glass transition (T_g =210 ºC) temperatures were reported.