QUANTIFICATION OF ORGANIC OXYGEN SPECIES ON THE SURFACE OF FRESH AND REACTED ARGONNE PREMIUM COAL

X-ray photoelectron spectroscopy (XPS) was used to determine the kinds of organic and inorganic oxygen species present in Argonne Premium co al. In most cases the XPS results for organic oxygen with fresh coal c ompare favorably with other methods of analysis. The evolution of CO2, CO, and H2O during pyrolysis at 400 degrees C was quantified, and the ir appearance was associated with the loss of hydroxyl and carboxyl gr oups in fresh coal. Oxidation of fresh coal at 125 degrees C in air re sulted in significant increases in the level of iron and inorganic sul fate on the coal surface. Oxidation of subbituminous and lower rank co al resulted in increases in the level of carboxyl species but decrease s in the level of hydroxyl species. The levels of carboxyl, carbonyl, and other species increase upon oxidation of bituminous and higher ran k coal. The advantages and limitations of the XPS approach for quantif ying organic oxygen functionalities in coal are discussed.