کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1198108 964689 2008 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Secondary reactions of lignin-derived primary tar components
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Secondary reactions of lignin-derived primary tar components
چکیده انگلیسی

Secondary reactions of lignin-derived primary tar components were studied with a closed ampoule reactor under the conditions of N2/600 °C/40–120 s. The tar fractions from Japanese cedar milled wood lignin and model compounds were characterized with the GPC, 1H NMR and GC/MS analyses. Changes in the tar composition indicated the following pathways; unsaturated side-chain (>CC<) and phenolic aromatic ring, both of which are the major structures of the primary tar fraction, are the most reactive structure and would be converted to the condensation products; Then, the side-chains are cracked to form the low MW aromatics with saturated alkyl groups or –H; decarbonylation of the aldehyde groups and change in the substitution pattern of the aromatic ring also occur along with this cracking reaction; the guaiacyl (4-hydroxy-3-methoxyphenyl)-type aromatic ring in the primary tar fraction is converted to the catechol-, o-cresol- and phenol-type aromatic rings. Although the pure catechol-type compounds were stable, these compounds became reactive in the presence of the guaiacol-type compounds. Radical chain reaction through the H-abstraction from the phenolic hydroxyl groups would activate the catechol-type compounds.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Analytical and Applied Pyrolysis - Volume 83, Issue 1, September 2008, Pages 78–87
نویسندگان
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