Comprehensive insights into xylan structure evolution via multi-perspective analysis during slow pyrolysis process

Comprehension in hemicellulose pyrolysis is critical to generate renewable fuel and valuable chemical. Herein, a self-designed tubular reactor was applied to observe the appearance alteration and chemical structure evolution during the whole xylan pyrolysis process. Before 200 °C, it was free moistu...

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Bibliographic Details
Published inFuel processing technology Vol. 186; pp. 1 - 7
Main Authors Liang, Jiajin, Chen, Jiao, Wu, Shubin, Liu, Chao, Lei, Ming
Format Journal Article
LanguageEnglish
Published Amsterdam Elsevier B.V 01.04.2019
Elsevier Science Ltd
Subjects
Aromaticity
Carbonation
Chain branching
Chains
Char
Cleavage
Decarboxylation
Dehydration
Depolymerization
Evolution
Hemicellulose
Ketones
Moisture removal
NMR spectroscopy
Nuclear fuels
Organic chemistry
Pyrolysis
Structure evolution
TG-FTIR
Pyrolysis
Structure evolution
Hemicellulose
Char
TG-FTIR
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Summary:Comprehension in hemicellulose pyrolysis is critical to generate renewable fuel and valuable chemical. Herein, a self-designed tubular reactor was applied to observe the appearance alteration and chemical structure evolution during the whole xylan pyrolysis process. Before 200 °C, it was free moisture removal stage without significant chemical structure alteration. Xylan began to depolymerize at 200 °C corresponding with the appearance change from its original state to dark brown, cleavage of branched-chain and primary product acids & ketones generation. The main chain of xylan was completely broken at 250–350 °C via β‑1,4‑glycosidic bond cleavage, dehydration, decarboxylation, and decarbonylation reaction. Acids were mainly originated from hemicellulose pyrolysis. The typical signals from FTIR, 13C CP/MAS NMR were disappeared at 350 °C. In the carbonation stage, the C/H and C/O ratio reached 2.01 and 4.54, leading to the aromaticity enhancement of char and formation of carbon-centered radicals. [Display omitted] •Comprehensive insights into xylan pyrolysis mechanism via multi-perspective analysis•The intermediate state of xylan formed at the second weightlessness stage•Acids were mainly originated from hemicellulose pyrolysis.•Biochar tended to form carbon-centered radicals at the carbonation stage.
ISSN:0378-3820
1873-7188
DOI:10.1016/j.fuproc.2018.12.014