1992 Volume 71 Issue 6 Pages 428-435
In the study of coal gasification, it's necessary to analyze the diffe-rent reactivity for coals. Then we estimated coal gasification reaction in point of macer-al, which was a component of coal, uniformly tried to evaluate the reactivity.
We prepared four demineralized coals (Taiheiyo, Datong, Wandoan, Plateau) by the HF-HCl treatment to remove the catalytic effect of ash and carried out density separa-tion of these coals by the ZnCl2 solution (density range; 1.20-1.50) to have some sam-ples with concentrated maceral from same coal. Every fractions were gasified in a CO2 stream under 850°C, using a thermobalance and measured the reaction rate and reaction order from TG-curve. Futhermore, some fractions were characterized by ultimate and proximate analysis, CO2 surface area, chemisorbed oxygen, 13C-NMR, maceral analysis, which showed different values. Apparently, the initial reaction rate based on CO2 sur-face area was proportional to acertain maceral ratio, the rate corrected by CO2 surface area and maceral ratio had an exponential relation to H/C ratio. Also the reaction order was proportional to the vitrinite ratio in maceral groups.
Consequently, it was possible that the reaction rate constant and reaction order were estimated uniformly with H/C ratio, CO2 surface area, and maceral ratio.
