Adsorption Selectivity of CO₂ and CH₄ on Novel PANI/Alkali-Exchanged FAU Zeolite Nanocomposites

چکیده مقاله

Adsorption capacity and selectivity of carbon dioxide (CO₂) and methane (CH₄) in faujasite (FAU)-type zeolites NaX and NaY have been studied by employing a volumetric measurements at 298, 323, and 348 K and a pressure range up to 5 bar. Ion exchange was performed on FAU zeolites with alkali metal cations Li⁺ and K⁺. The alkali-exchanged zeolitic adsorbents were characterized by scanning electron microscopy, X-ray diffraction and N₂ adsorption/desorption isotherms. CO₂ is highly adsorbed than CH₄ on alkali-exchanged zeolites. The adsorption capacity of CO₂ in alkali-exchanged zeolites decreases with increase in the cationic radius, while for CH₄ the adsorption capacity increases with increase in the extra framework cationic radius. The novel zeolitic nanocomposites (Li-FAU) were prepared by adding polyaniline (PANI) to the LiX and LiY with different weight percentages p% (p = 10, 20, 30 and 40%). The PANI/Li-FAU zeolite nanocomposites show higher adsorption capacity for CO₂ and selectivity of CO₂/CH₄ against the Li-FAU zeolites at different pressures. The maximum selectivity was observed at lower pressures at 298 K for LiX/PANI-40. © 2017, Springer Science+Business Media New York.