Analysis of formation rates of sulfur-containing gases during the pyrolysis of various coals

To clarify the relation between organic sulfur distribution in coal and the emission of sulfur-containing gases, six Japanese standard coals, three Argonne premium coals, and one Chinese coal were pyrolyzed using a thermogravimetric analyzer-mass spectrometer (TG-MS) and a Curie-point pyrolyzer. The changes in sulfur distributions in coal and chars were estimated by a modified controlled-atmosphere-programmed-temperature oxidation (CAPTO) method. It was clarified that the aliphatic sulfur decomposed below 500 degreesC and that the aromatic sulfur decomposed at 400-700 degreesC, irrespective of coal type. The decomposition of thiophenic sulfur was strongly affected by coal type. Finally, the H2S formation rate and the decomposition rate of organic sulfur were analyzed using a new distributed activation energy model (DAEM).