The Oxidation of Chars From Huainan Bituminous Coal

The effects of heating manner and charring temperature on chemical composition of chars from the pyrolysis of Huainan bituminous coal were investigated. The results show that the chars formed from Huainan bituminous coal by slowly heating to higher charring temperature have higher ash and carbon contents along with lower volatile matter, hydrogen, nitrogen, and sulfur contents. The yields of water-soluble portions, which, obtained from the oxidation of the extraction residues obtained at higher pyrolysis temperatures and for longer pyrolysis periods of time are higher; the water-soluble portions mainly consist of benzenepolycarboxylic acids, including phthalates to benzenehexacarboxylic acids, suggesting that the extraction residues obtained are composed of condensed aromatics. The above results provide an important scientific basis for understanding the compositions and high value-added utilizations of coal char.