Abstract:
Flash pyrolysis characteristics of four Chinese coals were studied in a Curie-pointed reactor and gas chromatography (Py-GC) combined system. The yield of volatile matter (
VM) and evolution of gaseous
VM components were measured. It is found that ≥ 50% of
VM is released at the early stage (
t ≤ 2 s) of flash pyrolysis. It needs ~10 s to totally devolatilize 1 mg coal in the Curie-point reactor with the sample wrapped in a ferromagnetic foil. The yields of gaseous
VM component are in the order of H
2 > CH
4 > CO > CO
2 > C2(C
2H
6, C
2H
4) > C3 (C
3H
8, C
3H
6). The yield of
VM increases as the pyrolysis temperature increases. Under the same pyrolysis condition, high
VM content coals released more
VM than the low
VM content ones. Yields of H
2 and CH
4 increase greatly with the pyrolysis temperature. Yields of CO and CO
2 depend on both the content of oxygen in the coal and pyrolysis temperature. Amounts of C2 and C3 gases are relatively much less than the others, accounting for less than 5% in volume in the gaseous
VM.