Preparation of activated carbons from Zonguldak region coals by physical and chemical activations for hydrogen sorption

Activated carbons were prepared by physical and chemical activations from coals collected from two mines (Kilimli and Armutcuk) in Zonguldak region, Turkey under different conditions. Ash content was reduced considerably by use of HCl and HF treatments. Pyrolytic thermal treatments in a temperature range of 600–900∘C under N2 flow and chemical treatments using different chemical agents such as KOH, NH4Cl, ZnCl2 were applied to the coal samples from the two mines. N2 adsorption isotherms were obtained at 77.4 K for the thermally and the chemically treated samples and the data were used for the evaluation of the specific surface area, total pore volumes and the average pore sizes of the samples. Higher surface area values were obtained from Kilimli coal samples than Armutcuk. The BET surface area of the Kilimli coal samples which were initially have a value of 1.20 m2/g were increased to 52.62 m2/g after pyrolytic heat treatments at 800∘C and increased to a value of 830.5 m2/g by treating the coals with KOH+NH4ClKOH+NH4Cl mixture at 750∘C followed by oxidation of the samples mixed with ZnCl2. The activated carbon samples were prepared for the purpose of their evaluation in hydrogen sorption studies.