Dynamic Behaviors of Sulfur Evolved in the Gas Phase from Pyrolysis of Six Chinese Coals

Dynamic behaviors of gaseous sulfur-containing compounds evolved from pyrolysis of six Chinese coals were studied in the temperature range of up to 800°C under N₂ and H₂. The released amount of total sulfur-containing gases was traced by an online flame photometric detector (FPD). Simultaneously, the changes of different sulfur forms, including H₂S, SO₂, COS and CS₂, also were investigated using an online mass spectrometer (MS). FPD results show that the effect of H₂ on gaseous sulfur evolved is complex, which promoted certain peak and suppresses other peaks. Based on the data from MS, it is suggested that a series of competitive reactions between active sulfur and other active matters during pyrolysis may impact on the sulfur form in gas phase. Interactions between active sulfur-containing intermediates and the coal matrix are attributed to be the main factor determining the dynamic behavior.