标题:Effect of steam concentration on demineralized coal char surface behaviors and structural characteristics during the oxy-steam combustion process
作者:Wang, Zhuozhi; Sun, Rui; Zhao, Yaying; Li, Yupeng; Ren, Xiaohan
作者机构:[Wang, Zhuozhi; Sun, Rui; Zhao, Yaying; Li, Yupeng] Harbin Inst Technol, Sch Energy Sci & Engn, Harbin 150001, Heilongjiang, Peoples R China.; [Zhao 更多
通讯作者:Sun, Rui;Sun, R;Li, YP
通讯作者地址:[Sun, R; Li, YP]Harbin Inst Technol, Sch Energy Sci & Engn, Harbin 150001, Heilongjiang, Peoples R China.
来源:ENERGY
出版年:2019
卷:174
页码:339-349
DOI:10.1016/j.energy.2019.02.187
关键词:Steam concentration; Demineralized char; C(O); NO reducibility
摘要:Oxy-steam combustion, fuel combusts in O-2/H2O atmosphere, is treated to be a novel and promising technology for the next generation oxy-fuel combustion. The purpose of this study is to identify the effects of steam concentration on NO emission characteristics, functional group distribution and char NO reducibility during oxy-steam combustion process. A typical bituminous coal (SH) was employed for demineralization, devolatilization, combustion in O-2/H2O environment, and investigated by Temperature Programmed Desorption/Reduction (TPD/TPR) methods and Raman spectrometer. The combustion results illustrated that char N/NO conversion during the oxy-steam combustion tests initially decreased with an increasing steam concentration in low range (1.2-8.5 vol.%), while increased apparently in high steam range (8.5-20 vol.%). Decomposition of H2O molecules promoted the formation of C(O) and small aromatic rings on particle surface at the low steam range; the high concentration of steam could promote the condensation of aromatic ring structures in char, leading to significant generation of large aromatic ring structures with a lower reactivity and the reduction of surface active sites (C-f). The TPD results illustrated that the chars oxidized at moderate steam concentration (8.5 vol.%), and the chars with moderate burnout degrees (such as S-3, S-6 and S-11) had the largest amount of C(O). Due to the decomposition of the C(O) into new C-f and massive CO molecules, a rapid acceleration of NO reduction rate occurred in the temperature range of 1000-1400 K during the TPR process of each sample obtained from identical reaction conditions. Thus, variations in char surface behavior and microstructure might be the primary reasons affecting char-N emission. (C) 2019 Elsevier Ltd. All rights reserved.
收录类别:EI;SCOPUS;SCIE
资源类型:期刊论文
原文链接:https://www.scopus.com/inward/record.uri?eid=2-s2.0-85062716583&doi=10.1016%2fj.energy.2019.02.187&partnerID=40&md5=f5d95774e7d70f4d4214b0f39711da84
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