4.7 Article

Modeling char surface area evolution during coal pyrolysis: Evolving characteristics with coal rank

期刊

出版社

ELSEVIER
DOI: 10.1016/j.jaap.2021.105110

关键词

Char surface area; Coal pyrolysis; Coal rank; Modeling; Metaplast

资金

  1. National Key Research and Development Program of China [2016YFB0600301]
  2. National Science Foundation for Young Scholars of China [21706025]
  3. Fundamental Research Funds for the Central Universities [DUT2018TB02]
  4. China Scholarship Council (CSC) [201806065065]

向作者/读者索取更多资源

The trend of changing N-2 adsorption specific surface area during pyrolysis is significantly affected by coal rank and the arrangement of planar polycyclic aromatic structures in char. Two exponents introduced in the model can predict the specific surface area of various coals and a correlation between the fraction ratio of crosslinked metaplast to volatile yield and the order degree of aromatic structure arrangement is proposed. The model can also predict transition characteristics of subbituminous coal based on temperature and heating rates.
The trend of changing char N-2 adsorption specific surface area (sN2) during pyrolysis depends on coal rank significantly, and this is influenced by the arrangement of planar polycyclic aromatic structures in char. Two exponents, k(mat order) and k(crlmet order), representing the order degrees of planar polycyclic aromatic structure arrangement in coal matrix and crosslinked metaplast, respectively, were introduced in the previous model, which could predict s(N2) of lignite coals and predict char CO2 adsorption specific surface area (s(CO2)) of lignite and high-volatile bituminous coals. A correlation between k(crlmet order) of s(N2) and f(cross)/f(v) (the fraction ratio of the crosslinked metaplast to the volatile yield) was proposed. The previous model was extended to include predicting N-2 adsorption specific surface area of char generated from subbituminous and high-volatile bituminous coals at atmospheric pressure and was validated with 5 subbituminous coals, and 2 bituminous coals. The change of s(N2) with coal ranks was explained by the change of k(crlmet order) with f(cross)/f(v). When the crosslinked metaplast is adequate and the volatile yield is small, the planar polycyclic aromatic structures in metaplast overlap tightly and s(N2) is small. When the crosslinked metaplast content is small and the volatile yield is big, the metaplast is arranged disorderly, making s(N2) in crosslinked metaplast larger than that in the coal matrix and take a considerable proportion of total char surface area. The transition characteristics of subbituminous coal can be predicted by the improved model. When the temperatures and heating rates are high enough, the predicted s(N2) of subbituminous coals changed more like lignite coals, while at lower temperatures and heating rates, the predicted s(N2) changed like high-volatile bituminous coals.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.7
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据