Effects of oxygen on the structure and reactivity of char during steam gasification of Shengli brown coal

SUN Jia-liang; CHEN Xu-jun; WANG Fang; LIN Xiong-chao; WANG Yong-gang

Volume 43 Issue 07

Jul. 2015

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SUN Jia-liang, CHEN Xu-jun, WANG Fang, LIN Xiong-chao, WANG Yong-gang. Effects of oxygen on the structure and reactivity of char during steam gasification of Shengli brown coal[J]. Journal of Fuel Chemistry and Technology, 2015, 43(07): 769-778.

Citation:

SUN Jia-liang, CHEN Xu-jun, WANG Fang, LIN Xiong-chao, WANG Yong-gang. Effects of oxygen on the structure and reactivity of char during steam gasification of Shengli brown coal[J]. Journal of Fuel Chemistry and Technology, 2015, 43(07): 769-778.

Citation:

SUN Jia-liang, CHEN Xu-jun, WANG Fang, LIN Xiong-chao, WANG Yong-gang. Effects of oxygen on the structure and reactivity of char during steam gasification of Shengli brown coal[J]. Journal of Fuel Chemistry and Technology, 2015, 43(07): 769-778.

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Effects of oxygen on the structure and reactivity of char during steam gasification of Shengli brown coal

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

Funds: The 12th Five-Year Plan of National Science and Technology Support (2012BAA04B02).

Received Date: 2015-02-03
Rev Recd Date: 2015-05-30
Publish Date: 2015-07-30

Abstract

Abstract

The effects of oxygen on changes in char structure and reactivity during steam gasification of Shengli brown coal were examined. A stainless steel simulated entrained-flow reactor was employed to carry out gasification at 800 and 900 ℃ in 8 atmospheres: pure N₂, 15% H₂O, 25%H₂O and 35%H₂O balanced with N₂; and 1%O₂, 15%H₂O+1%O₂, 25%H₂O+1%O₂ and 35%H₂O+1% O₂ balanced with N₂. The structure of chars was measured by Raman spectrum, and the intrinsic reactivity of chars with air was measured using a thermogravimetric analyzer (TGA) at low temperature (300 ℃). The results show that the effects of oxygen on char structure are different at high temperature (900 ℃) and low temperature (800 ℃) in brown coal steam gasification. The volatilization of alkali and alkaline earth metallic (AAEM) is strongly influenced by char structure. The presence of O₂ during steam gasification has a similar effect on the volatilization of Na to the evolution of structure at different temperatures. Experimental data provided evidence that a mixed H₂O/O₂ atmosphere could promote a decrease in subsequent char reactivity in air at 300 ℃, and that char reactivity could correlate well with the band area ratio, I_{(G_R+V_L+V_R)}/I_D.
- brown coal,
- gasification,
- char structure,
- char reactivity,
- simulated entrained-flow reactor

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References(29)

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