Biomass-derived porous carbons are regarded as the most preferential adsorbents for CO₂ capture due to their well-developed textural properties, tunable porosity and low cost. Herein, novel porous carbons were facilely prepared by activation of palm sheath for the highly selective separation of CO₂ from gas mixtures. The textural features of carbon materials were characterized by the analysis of surface morphology and N₂ isotherms for textural characterization. The as-prepared carbon adsorbents possess an excellent CO₂ adsorption capacity of 3.48 mmol g⁻¹ (298 K) and 5.28 mmol g⁻¹ (273 K) at 1 bar, and outstanding IAST selectivities of CO₂/N₂, CO₂/CH₄, and CH₄/N₂ up to 32.7, 7.1 and 4.6 at 298 K and 1 bar, respectively. Also, the adsorption evaluation criteria of the vacuum swing adsorption (VSA) process, the breakthrough experiments, and the cyclic experiments have comprehensively demonstrated the palm sheath derived porous carbons as efficient adsorbents for practical applications.