Study on the submicron and micron morphology and the properties of poor bituminous coal burnout

• Published in: Asia-Pacific journal of chemical engineering 2007-05, Vol.2 (3), p.190-196
• Main Authors: Fu, Pei-Fang, Zhou, Huai-Chun, Fang, Qing-Yan, Yao, Hai, Qiu, Jianrong, Xu, Minghou
• Format: Article
• Language: English
• Subjects: char burnouts; components of micron field; eutectic reaction; FSEM; submicron morphology
• ISSN: 1932-2135; 1932-2143
• DOI: 10.1002/apj.40

Carbon burnout and its reaction mechanism have been widely focused on in the past decades. The properties of burnout, submicron and micron morphology and the reaction mechanism of poor bituminous coal/char (PBC) in a W‐shaped power plant boiler was studied and was compared with those in DTF and in TGA, which showed that the degree of PBC burnout in TGA at 1450 °C was greater than or approximately equal to that in a W‐shaped boiler, and that the complexity of the reactions among residual char, oxygen and SiO2 did not apparently result in mass loss in TGA, although the weight percentage of the residual char in ash decreased from 33% ad (air dry basis) at 900 °C to 9% ad at 1450 °C. According to the distribution of pores and the properties of the char burnout, the char can be simply categorized into three classes: char burnout easy, char burnout difficult and char burnout very difficult. The differences of the reaction mechanism must be considered while predicting the burning rate and degree of char burnout in a full‐scale boiler by making use of experimental results from TGA and DTF. A different char particle contains markedly different amount of carbons, but for a special char particle, the ratio of carbon to ash is generally constant, and an ash shell does not exist on the char surface. The fusion mineral matter composing of C‐O‐Si‐Al is amorphous, not in the form of Al2O3 and SiO2 above 1450 °C. Copyright © 2007 Curtin University of Technology and John Wiley & Sons, Ltd.