<p>In this work, for first time, chilli pepper-drived compounds, namely Capsaicin and β-carotene, were utilized to enhance the gas separation efficiency of PMP membranes for CO₂ removal from N₂ and CH₄. The modified membranes were synthesized by incorporating 1 to 5 wt% of Capsaicin and β-carotene. The synthesis of the modified membranes was carried out by FTIR, SEM, EDX and DMTA tests. Gas permeability measurements were conducted on pure and modified membranes at 30 ℃ and pressures of 2, 6 and 10&#xa0;bar. The results of gas permeation tests illustrated that the CO₂ permeability, CO₂/N₂ and CO₂/CH₄ selectivities in pure PMP membrane were 96.7 barrer, 10.86 and 8.41, respectively. In addition, it was concluded that the incorporation of Capsaicin and β-carotene into the PMP polymer matrix significantly enhanced the membrane’s separation performance. In comparison with the pure PMP membrane, the CO₂ permeability improved by 53.46% and 32.78% for the modified membranes containing 5 wt% Capsaicin and 4 wt% β-carotene, respectively. Furthermore, a marked improvement in CO₂ selectivity over N₂ and CH₄ was observed. Specifically, the CO₂/N₂ and CO₂/CH₄ selectivities increased by 48.52% and 45.95% for the Capsaicin-loaded membrane, and by 27.1% and 27.4% for the β-carotene-loaded membrane, respectively. These enhancements highlight the potential of bio-based additives in promoting the gas separation efficiency of polymeric membranes.</p>