JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY, vol.129, no.1, pp.441-449, 2017 (SCI-Expanded)
In this study, the adsorption of methane (CH4) on chabazite tuff from Bala, Turkey, and that of salt-treated forms (Na+, K+, Li+, Ca2+ and Mg2+) was investigated. Structural and thermal characterization of chabazite samples were examined using X-ray diffraction, X-ray fluorescence, thermogravimetry, differential thermal analysis and N-2 adsorption methods. The heats of immersion of the zeolite samples were measured with a Calvet-type C-80 calorimeter. At 30 A degrees C, the Q (imm) values for heat of immersion decreased in the following order: Mg-CHA (113.62 J g(-1)) > Li-CHA (112.82 J g(-1)) > CHA (108.50 J g(-1)) > Ca-CHA (99.82 J g(-1)) > Na-CHA (80.00 J g(-1)) > K-CHA (63.79 J g(-1)). Adsorption properties of methane for all chabazite samples were obtained at 0 and 25 A degrees C pressures up to 100 kPa. It was found out that CH4 adsorption capacities of the natural and salt-treated chabazites at 0 A degrees C (0.831-1.315 mmol g(-1)) were higher than those at 25 A degrees C (0.672-1.163 mmol g(-1)) as expected.