ABSTRACT
The present study is concerned with the pyrolysis of ten kinds of coals of different rank in which of fuel ratio ranges relatively widely from 0.9 to 6.6. The coal pyrolysis experiment was carried out using Thermogravimetric Analysis (TGA) in an atmosphere of nitrogen under the following conditions: coal particle size 37-2000 pm, heating rate 2-2000 K/min. The pyrolysis parameters as the reaction order, the activation energy and the frequency factor were determined, and then these were correlated with the ratio of percent carbon to percent volatile matter, referred to as the fuel ratio. From the results, it was recognized that the experimental data were well reproduced with respect to TG curves by means of the determined parameters. The behaviours of volatile-N released from original coals of different ranks were investigated during coal pyrolysis. The results show that volatile-N starts to be released from coal when the temperature reaches about 673-773 K, which is about 50-100°C higher than the temperature where volatile-C and volatile-H start to be released; The conversion of volatile-N increases with a decrease of fuel ratio at same heating temperature.
