文献类型：期刊文献

英文题名：Study on effects of ash on the evolution of physical and chemical structures of char during CO2 gasification

作者：Zou, Xiaopeng[1];Ding, Lu[2];Liu, Xia[1];Guo, Qinghua[1];Lu, Haifeng[1];Gong, Xin[1]

机构：[1]East China Univ Sci & Technol, Engn Res Ctr Coal Gasificat, Minist Educ, Key Lab Coal Gasificat & Energy Chem Engn, Shanghai 200237, Peoples R China;[2]Tokyo Inst Technol, Sch Environm & Soc, Midori Ku, G5-8,4259 Nagatsuta, Yokohama, Kanagawa 2268502, Japan

年份：2018

卷号：217

起止页码：587

外文期刊名：FUEL

收录：;EI(收录号：20181104895434);WOS:【SCI-EXPANDED(收录号:WOS:000427818900061)】；

基金：The present work was supported by the Sinopec Scientific and Technological Development Projects (415022) and the Fundamental Research Funds for the Central Universities (222201414030).

语种：英文

外文关键词：Gasification; Char conversion; Demineralization; Specific surface area; Raman spectrum

摘要：In this paper, the gasification reactivities of four types of Chinese coal were studied, each with different ash content and coal rank. Of the 4 coal types, 2 were HCl-washed and demineralized to investigate the effects of ash removal (for both dealkalization and demineralization) on coal gasification. The effects of ash on the evolution of physical and chemical structure were further studied using scanning electron microscopy equipped with energy dispersive X-ray analysis (SEM-EDX), N-2 absorption and FT-Raman techniques. The results show that the initial gasification rate of raw chars is twice as high as the HCl-washed and ash-free chars. The gasification rate of ash-free char significantly increases with the increase in carbon conversion and surpasses the gasification rate of raw char when carbon conversion is higher than 50%. Moreover, the specific surface area of ash-free char significantly increases with carbon conversion, resulting in the significant increase in the gasification rate. Whereas the specific surface areas of raw char and HCl-washed char both decrease during high-conversion stages. The FT-Raman analysis shows that the ash-free char band area ratios A(D3)/A(G) and A(D4)/A(G) are lower than those of raw char at the initial gasification stage; this results in the initial gasification rate decrease of ash-free chars. In addition, the ash-free char band area ratio A(G)/A(all) is smaller than that of raw char in the high conversion stages.