Pressurized Fast-Pyrolysis Characteristics of Typical Chinese Coals with Different Ranks

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• 作者：Chunyu Li ; Jiantao Zhao ; Yitian Fang ; Yang Wang
• 刊名：Energy & Fuels
• 出版年：2009
• 出版时间：October 15, 2009
• 年：2009
• 卷：23
• 期：10
• 页码：5099-5105
• 全文大小：1100K
• 年卷期：v.23,no.10(October 15, 2009)
• ISSN：1520-5029

文摘

The pressurized fast pyrolysis of three typical Chinese coals with different coal ranks (Huolinhe lignite, Shenmu bituminous coal, and Jincheng anthracite) was conducted on a self-made pressurized fixed-bed reactor. The physicochemical characteristics of the chars were studied via scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). In addition, thermogravimetric analysis (TGA) at ambient pressure has been used to study the influence of the residence time, the pyrolysis temperature, and pressure on the gasification reactivity of residual chars. The results show that the change in char yield and reactivity with pressure, at a residence time of 1 min, is different from that at longer residence time. This is related to the changing impacts of the rapid primary release of volatiles and the slower secondary cracking reactions of the evolved tars and the graphitization of the char structure. Furthermore, as the coal rank, pyrolysis pressure, temperature, and residence time increase, the surface structure of the char becomes much denser, the degree of graphitization is enhanced, and the number of the functional groups is reduced, which lead to the decrease in the gasification reactivity of the coal char.