Study on the pyrolysis behavior of Shendong Shangwan coal and its macerals concentrate

The pyrolysis characteristics of Shendong Shangwan coal and its macerals concentrate were investigated using thermogravimetry (TG) coupled with mass spectrometry (MS). The evolved gases were analyzed online by MS spectroscopy. The results of TG/DTG (derivative thermogravimetry) show ths vitrinite concentrate has greater weight loss rate and higher volatile yield than the other two samples. More light hydrocarbons C1-C5 are released from the vitrinite concentrate than from the Shendong Shangwan coal and inertinite concentrated in the process of pyrolysis. Three samples have similar shape curves of evolved gases of C2–C5 with different intensities. When the pyrolysis temperature was lower than 418 °C, the amount of C6H6 evolved in the process of pyrolysis of inertinite concentrated was higher than that of raw coal and vitrinite concentrate. As the temperature rising, the production rate of C6H6 increased. Below 672 °C, C6H6 evolution rate of vitrinite concentrate was far greater than the other two samples; the main evolution temperature range of C7H8 was 400 °C to 700 °C for the three samples. The amount of H2 and H2O released first increased and then decreased with the temperature increase while more H2 released for pyrolysis of inertinite concentrated and more H2O released for the pyrolysis of vitrinite concentrate.