Organosulfur Compounds in CS2 Extractable-Fractions from Four Chinese Coals Oxidized with NaOCl

Abstract

Four Chinese coals were oxidized with NaOCl aqueous solution under mild conditions. The reaction mixture was extracted with diethyl ether, carbon disulfide, petroleum ether, acetic ester and benzene sequentially. A series of organosulfur compounds (OSCs) were identified in the carbon disulfide fraction from the oxidized coals by GC/MS analysis but no OSCs were detected from other fractions except for 3 thiophene polycarboxylic acids found in ether-extraction. Some new types of sulfur function groups were also detected in the coal oxidation products which were not previously reported from coals. The results revealed that macromolecule OSCs in coals can be effectively degraded to water soluble small molecules with NaOCl aqueous solution, which can be enriched by carbon disulfide. Understanding the distribution of OSCs forms in coals matrix is useful in high value-added utilization of coals and coal desulphurization technologies.