EFFECTS OF VOLATILE-CHAR INTERACTION ON THE GASIFICATION OF A VICTORIAN BROWN COAL AT 800 ℃: COMPARISION BETWEEN GASIFICATION IN STEAM AND CO2

摘要

This study aims to investigate the effects of volatile-char interaction on coal conversion during the gasification of a Victorian brown coal at 800 ℃ in steam and CO2 in a novel quartz fluidised-bed reactor. Volatile-char interaction time was varied to examine the effects of the extent of volatile-char interaction on coal conversion during gasification. The reactivities of the chars from the partial gasification in CO2 and steam were also measured in a thermogravimetric analyser at 400 ℃ in air. Our results indicate that the volatile-char interaction has a significantly negative effect on coal conversion. The reactivity in air at 400 ℃ of the chars from the partial gasification in steam shows different magnitude from that of the chars from the partial gasification in CO2. These results appear to imply that there were different reaction pathways for char-H2O and char-CO2/char-O2 reactions.