Characterization of Microporous Structures in Reed Char for Molecular Sieve Applications

This study investigates the production of molecular sieving carbon (MSC) from reed biomass through carbonization and evaluates its pore structure and gas separation performance for CO₂-CH₄ and propylene-propane systems. Reed powder was carbonized under nitrogen at temperatures between 400 and 900℃. Up to 600℃, pore diameters increased and distributions broadened due to volatile release. Above 600℃, the formation of polycyclic aromatic structures resulted in smaller pore diameters and narrower distributions. For CO₂-CH₄ separation, char obtained at 800℃ exhibited an adsorption rate ratio (CO₂/CH₄) of approximately 20, indicating the potential for rate-based separation. In the propylene-propane system, char carbonized at 800℃ selectively adsorbed propylene, enabling equilibrium-based separation, while char at 600℃ achieved an adsorption rate ratio (propylene/propane) of approximately 30, suggesting rate-based separation capability.