Abstract
Concerning to the integrated gasification combined cycle (IGCC) which is a highly effective coal power plant, the improvement of cold gas efficiency is expected by utilizing steam as a gasifying agent effectively. However, the temperature in the gasification furnace will decrease owning to steam injection, so evaluating the effects of temperature on gasification reaction is an important study. In this study, the effects of pyrolysis temperature on char gasification reactivity were investigated. Pyrolysis experiments of sub-bituminous coal were carried out at 1173K, 1273K, 1373K, 1473K and 1673K using drop tube furnace (DTF) to produce the several types of char, and then gasification experiments were carried out using thermogravimetric analysis (TGA). As a result, char gasification reaction ratio was raised when the pyrolysis temperature was lower and it was found that pyrolysis temperature influenced on the characteristics of char. In order to investigate the relation between pyrolysis temperature and gasification reaction ratio, prepared char was analyzed by BET, XRD, and TEM-EDX. According the result of X-ray diffraction (XRD) analysis, it was found that graphitization degree was different owning to the difference of pyrolysis temperature. Moreover, according to the result of TEM-EDX analysis, it was found that iron contents were highly dispersed in char.
