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.

Keywords:

• dynamic behavior
• sulfur-containing gases
• pyrolysis
• FPD
• MS

The project is subsidized by the Special Funds for Major State Basic Research Project (G19990221), the Chinese Academy of Sciences, and the Natural Science Foundation of China (29725614, 20076050, and 20076049), and the State Key Laboratory of Coal Conversion.