ACTIVATED CARBON PRODUCED FROM AN ILLINOIS BASIN COAL

Activated carbons were produced from an Illinois Basin bituminous coal (IBC-106) by a three-step process: oxidation of the coal in air at 15 0-250 degrees C for 2-40 hours, devolatilization of these oxidized coa ls in nitrogen at 500-730 degrees C for 1 hour and activation (gasific ation) of the chars in 45% steam, 4% oxygen in nitrogen at 730-880 deg rees C for 3.5-96 hours. Products were characterized in terms of CO2 s ingle-point BET surface area, helium and bulk densities, pore volume a nd toluene adsorption capacity. Seven of the nine carbons produced had surface areas exceeding 1000 m(2) g(-1) (dry). It was confirmed that the application of oxidation pretreatment eliminates the caking of IBC -106, preserves the coal's microstructure, and leads to high carbon su rface areas. In comparison with Darco coconut charcoal, a commercial a ctivated carbon (Fisher Scientific) whose surface area was 547 m(2) g( -1) (dry), the largest toluene adsorption capacity of activated carbon s was 1.57 g g(-1), four times more than that of Darco. Production cos ting analysis on a laboratory scale suggested that, in a single produc tion run, the most cost-effective final product is not the activated c arbon with maximum surface area but the carbon produced at the lowest cost for each square meter of pore surface area. (C) 1997 Elsevier Sci ence Ltd.