文献类型：期刊文献

英文题名：Deduction of lignite liquefaction mechanism based on carbon structure analysis and free radical determination

作者：Chen, Lishi[1,2];Li, Huan[2,4];Zhang, Yuanyuan[2];Pan, Tieying[3];Zhang, Dexiang[2]

机构：[1]YUNNAN TIN NEW Mat CO LTD, Kunming 650106, Yunnan, Peoples R China;[2]East China Univ Sci & Technol, Dept Chem Engn Energy Resources, Shanghai 200237, Peoples R China;[3]East China Univ Sci & Technol, Anal & Res Ctr, Shanghai 200237, Peoples R China;[4]Kunming Univ Sci & Technol, Fac Chem Engn, Kunming 650500, Yunnan, Peoples R China

年份：2024

卷号：114

外文期刊名：JOURNAL OF THE ENERGY INSTITUTE

收录：;EI(收录号：20241415836545);WOS:【SCI-EXPANDED(收录号:WOS:001218805000001)】；

基金：Acknowledgements This work was supported by the National Key Research and Devel- opment Program of China (2016YFB0600303) , the Natural Science Foundation of Shandong Province (grant ZR2021QB103) .

语种：英文

外文关键词：Lignite liquefaction; Liquefaction oil; Carbon structure; Free radicals

摘要：The liquefaction performance of lignite is closely related to its structural evolution. The carbon structure and the free radical concentrations of Naomaohu (NMH) coal and liquefaction products were characterized by modified nuclear magnetic resonance (NMR) spectroscopy and electron paramagnetic resonance (EPR), respectively. The results showed that the oil yield increased gradually with the increase in temperature, and it reached a maximum of 64.91% at 430 degrees C. The carbon spectrum of the liquefied oil showed that the increase in temperature had little effect on the aromatic carbon connected with the aliphatic carbon, but had a greater effect on the aromatic proton carbon of the liquefied oil. The stability of aromatic carbon in asphaltene was greater than that of aliphatic carbon, and the temperature rise had a significant impact on the different types of aliphatic carbon of the asphaltene. The aromatic side chain of asphaltene gradually broke, and the bridgehead carbon content of the aromatic carbon increased due to the intensification of the condensation reaction at high temperature. On the other hand, the concentration of free radicals in liquefied oil increased with temperature, while the concentration of free radicals in asphaltene first increased and then decreased with temperature, indicating a positive correlation between its change trend and respective yield. With the increase in temperature, the aromatic ring substances with strong bond energy were gradually opened, the side chains were broken, thus forming more low molecular compounds. In summary, based on the above changes in the carbon structure and free radicals, the lignite pyrolysis and liquefaction mechanism have been deduced at the molecular level.