Influence of Chemical Pretreatment on the Adsorption of N 2 and O 2 in Ca-Clinoptilolite

Separations

article

Miguel Ángel Hernández¹  Gabriela I. Hernández²  Roberto Ignacio Portillo³  Ma de los Ángeles Velasco¹  Juana Deisy Santamaría-Juárez⁴  Efraín Rubio⁵  Vitalii Petranovskii⁶ 

[1] Departament of Zeolites Research, Posgraduate in Agroecology, ICUAP, Meritorious Autonomous University of Puebla;Department of Process Engineering, Metropolitan Autonomous University-Iztapalapa;Faculty of Chemical Sciences, Meritorious Autonomous University of Puebla;Faculty of Chemical Engineering, Meritorious Autonomous University of Puebla;University Center for Linking and Technology Transfer, Meritorious Autonomous University of Puebla;Nanosciences and Nanotechnology Center

关键词: clinoptilolite;    zeolite;    N2;    O2;    adsorption;    low coverage;    chromatography;   

DOI  :  10.3390/separations10020130

学科分类：社会科学、人文和艺术（综合）

来源: mdpi

【 摘 要 】

N2 and O2 adsorption isotherms in chemically modified clinoptilolite-Ca zeolites were experimentally estimated by inverse adsorption chromatography. Natural zeolites (CLINA) were chemically treated with HCl at different concentrations (H1-H4). The adsorption of N2 and O2 on these zeolites was studied in the temperature zone of 398–498 K using gas chromatography. This technique used a thermal-conductivity detector and He as carrier gas, at a rate of 30 mL min−1. The Langmuir and Henry equations were used to describe the experimental results of these gases’ adsorption. To evaluate the selectivity of the components of atmospheric air, the chemical activation of the zeolite clinoptilolite-Ca has been carried out. The results are attractive because of the ability to separate the gases these nanomaterials present under dynamic conditions. The structural modifications of the crystalline phases of the studied zeolites were carried out through X-ray diffraction, where the average crystal size was evaluated with the Scherrer equation, finding values of 25.86 nm for CLINA and 15.12 nm for H3 zeolites. The variation of their chemical composition was carried out by energy-dispersive EDS, while the adsorption of N2 carried out their texture properties at 77 K. The selectivity coefficients (α) were evaluated for these gases in pure form and in a mixture (atmospheric air), finding the highest values in zeolites H4 and H3. The interaction energies between these gases with the porous structures of the studied zeolites were evaluated from the evolution of the isosteric enthalpies of adsorption through the Clausius–Clapeyron equation.

【 授权许可】

CC BY