Influence of External Clay and Inherent Minerals on Lignite Optical Ignition and Volatile Flame Propagation in Air-Firing and Oxy-Firing
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- 作者：Wirhan Prationo ; Jian Zhang ; Hawra Ali Abdul Abbas ; Xiaojiang Wu ; Xiaodong Chen ; Lian Zhang
- 刊名：Industrial & Engineering Chemistry Research
- 出版年：2014
- 出版时间：February 19, 2014
- 年：2014
- 卷：53
- 期：7
- 页码：2594-2604
- 全文大小：614K
- ISSN：1520-5045
文摘
The influence of external clay additive and inherent minerals on the ignition of a Xinjiang lignite and its volatile flame propagation in air versus oxy-fuel combustion have been clarified in this work, through the use of a flat-flame burner reactor (FFBR) coupled with in-situ optical diagnosis tools. As has been confirmed, ignition of the lignite studied in this paper was initiated by homogeneous oxidation of a tarry volatile cloud. The removal of HCl-soluble metals shifted coal devolatilization toward higher temperatures in air and 21% O2 in CO2. The mixing of external clay with coal had little effect on the ignition time. However, it enhanced the decomposition of volatiles, leading to a larger volatile cloud shielding on the particle surface. The oxygen fraction in the bulk gas was found to be most influential. Increasing the oxygen fraction to 30% eliminated all of the discrepencies between raw lignite, acid-washed lignite, and a mixture of raw lignite and clay.