PREPARATION OF ACTIVATED CARBONS FROM BITUMINOUS COALS WITH CO2 ACTIVATION - INFLUENCE OF COAL OXIDATION

In this study activated carbons were prepared from three Australian bi tuminous coals. The influence of coal oxidation on the carbonization a nd activation processes and the structure of the resulting activated c arbons were explored. The oxidation was conducted at 200 degrees C in O-2 for 6 hours. During the oxidation the amount of oxygen uptake decr eased with the O/C atomic ratio of the raw coal. The carbonization of the oxidized coal exhibited a broader volatile evolution with respect to temperature, and the resulting char from the oxidized coal had a la rger surface area. The oxidation of the coal precursors resulted in in creases in the specific surface area and pore volume of the resulting activated carbons. For the carbons from the oxidized coals, the activa tion rate in CO2 was higher and the structure more accessible for CO2 penetration. (C) 1997 Elsevier Science Ltd. All rights reserved.