Structural and thermal characterization of acid activated and Ag-, Cu-, and Fe- exchanged chabazite zeolite

In this study, the structural, thermal and adsorption properties of natural zeolite from Ankara-Bala region and those of forms treated with exchanged with 1 M heavy metal nitrate solutions (DSAB, CuSAB, FeSAB and AgSAB) and 0.1, 0.5, 1, 2, 3 M HCl solutions (01HSAB, 05HSAB, 1HSAB, 2HSAB and 3HSAB) was investigated. Zeolite samples were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy coupled with energy dispersion spectroscopy (SEM/EDS), thermogravimetric/differential thermal analysis (TGA/DTA) and nitrogen adsorption methods. Quantitative XRD analysis showed that the major component of the natural zeolite were chabazite and together with minor amounts of clinoptilolite and erionite. Adsorption isotherms of CH4 (methane) by zeolite samples were obtained using volumetric apparatus at 0 oC and 25 oC up to 100 kPa. It was found out that the adsorption capacity and the affinity of CH4 with chabazite zeolites depended mainly on the type of exchanged cations and decreased as AgSAB > DSAB > CuSAB > 01HSAB > FeSAB > 05HSAB > 1HSAB > 2HSAB > 3HSAB for 25 °C up to 100 kPa. The uptake of methane decreased as AgSAB > CuSAB > DSAB > 01HSAB > 05HSAB > FeSAB >1HSAB > 2HSAB > 3HSAB for 0 °C up to 100 kPa.