Mechanistic investigation of char growth from lignin monomers during biomass utilisation
Mechanistic investigation of char growth from lignin monomers during biomass utilisation
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DOI：
10.1016/j.fuproc.2022.107556
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发表时间：
2023-01
影响因子：
7.5
通讯作者：
Alexander Shaw;Xiaolei Zhang;Shuya Jia;Juan Fu;Lin Lang;Robert C. Brown
中科院分区：
文献类型：
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作者：
Alexander Shaw;Xiaolei Zhang;Shuya Jia;Juan Fu;Lin Lang;Robert C. Brown
焦炭是生物质热解的重要产物，木质素是产生焦炭的最大贡献者。木质素焦的结构在文献中得到了很好的研究;然而，缺乏对木质素焦形成机理的阐明，这对于实现生物质热转化的精确控制是必不可少的。本文采用密度泛函理论（DFT）研究了β-O-4键衍生的木质素单体的成炭过程，并通过缓慢热解实验和核磁共振（NMR）分析进行了验证。结果表明，炭的形成在一个两步的过程中，开始与两个单芳香族物种的聚集，以产生三环物种，然后参与进一步的成环反应，以产生更大的芳香族簇。产生的副产物包括氢气、水、甲醇和甲醛。从所提出的机制的见解是重要的，指导未来的研究在生物质热化学转化过程中的焦炭形成。
Char is formed as a significant product from the pyrolysis of biomass, and it is well reported that lignin is the greatest contributor to the production of char. The structures of lignin chars are well studied in literature; however, an elucidation on the lignin char formation mechanism is lacking and this is essential to achieve precise control of biomass thermal conversion. In this work, the char growth process from β-O-4 linkage derived lignin monomers was investigated using density functional theory (DFT) and validated by slow pyrolysis experiments and Nuclear Magnetic Resonance (NMR) analysis. It was shown that char forms in a two-step process, beginning with the aggregation of two mono-aromatic species to yield tricyclic species, which then participate in further ring forming reactions to yield larger aromatic clusters. The side products generated involve hydrogen, water, methanol, and formaldehyde. Insights from the proposed mechanism are important for guiding future research on char formation during biomass thermochemical conversion processes.