Effects of steam on the reactivity and microstructure of char from in-situ gasification of brown coal

XU Xiu-qiang; WANG Yong-gang; CHEN Guo-peng; CHEN Zong-ding; QIN Zhong-yu; DAI Jin-ze; ZHANG Shu; XU De-ping

Volume 43 Issue 05

May 2015

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Article Navigation > Journal of Fuel Chemistry and Technology > 2015 > 43(05): 546-553

XU Xiu-qiang, WANG Yong-gang, CHEN Guo-peng, CHEN Zong-ding, QIN Zhong-yu, DAI Jin-ze, ZHANG Shu, XU De-ping. Effects of steam on the reactivity and microstructure of char from in-situ gasification of brown coal[J]. Journal of Fuel Chemistry and Technology, 2015, 43(05): 546-553.

Citation:

XU Xiu-qiang, WANG Yong-gang, CHEN Guo-peng, CHEN Zong-ding, QIN Zhong-yu, DAI Jin-ze, ZHANG Shu, XU De-ping. Effects of steam on the reactivity and microstructure of char from in-situ gasification of brown coal[J]. Journal of Fuel Chemistry and Technology, 2015, 43(05): 546-553.

Citation:

XU Xiu-qiang, WANG Yong-gang, CHEN Guo-peng, CHEN Zong-ding, QIN Zhong-yu, DAI Jin-ze, ZHANG Shu, XU De-ping. Effects of steam on the reactivity and microstructure of char from in-situ gasification of brown coal[J]. Journal of Fuel Chemistry and Technology, 2015, 43(05): 546-553.

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Effects of steam on the reactivity and microstructure of char from in-situ gasification of brown coal

School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China

Received Date: 2014-11-26
Publish Date: 2015-05-30

Abstract

Abstract

To examine the effects of steam on the char reactivity and its microstructure, experiments of drying and pyrolysis of brown coal as well as the in-situ gasification of "hot" char were carried out in a newly-designed two-stage reactor. The reactivity and microstructure of in-situ gasification char were characterized by TGA, BET and Raman spectroscopy respectively. The results show that at low temperature of 600 ℃, the steam has little effect on the conversion, reactivity and microstructure of char. When it reaches 700~900 ℃, there are different change trends before and after 2 min of reaction between char and steam. In the first 2 min, the reactivity, the ratio of small aromatic ring systems (3~5 rings) to the large fused rings (≥6 rings) and O-containing functional groups decrease dramatically although the char conversion varies little; after 2 min, however, char conversion increases gradually, char reactivity, the ratio of small to big aromatic ring systems and O-containing functional groups decrease slowly. In addition, the pore structure of char follows almost the same variation before and after 2 min. During the first 2 min, a sharp decrease of the ratio of small to big aromatic ring systems and O-containing functional groups are the important factors leading to the decrease of char reactivity; while after 2 min, the change of aromatic ring systems results in the further decrease of char reactivity.
- brown coal,
- char,
- steam,
- in-situ gasification,
- reactivity,
- microstructure

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References(27)

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