scholarly journals Pyrolysis Products Distribution of Enzymatic Hydrolysis Lignin with/without Steam Explosion Treatment by Py-GC/MS

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 187
Author(s):  
Yuguo Dong ◽  
Xinyu Lu ◽  
Chengjuan Hu ◽  
Liang Li ◽  
Qixiang Hu ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Steam Explosion ◽  
Pyrolysis Product ◽  
Product Distribution ◽  
Hydroxyl Group ◽  
Hydrolysis Lignin ◽  
Pyrolysis Gas ◽  
Pyrolysis Products ◽  
Structural Framework ◽  
Main Component

This paper investigated the pyrolytic behaviors of enzymatic hydrolysis lignin (EHL) and EHL treated with steam explosion (EHL-SE) by pyrolysis-gas chromatography/mass spectrometer (Py-GC/MS). It was shown that the main component of the pyrolysis products was phenolic compounds, including G-type, H-type, S-type, and C-type phenols. With different treatment methods, the proportion of units in phenolic products had changed significantly. Meanwhile, proximate, elemental, and FTIR analysis of both lignin substrates were also carried out for a further understanding of the lignin structure and composition with or without steam explosion treatment. FTIR result showed that, after steam explosion treatment, the fundamental structural framework of the lignin substrate was almost unchangeable, but the content of lignin constituent units, e.g., hydroxyl group and alkyl group, evidently changed. It was noticeable that 2-methoxy-4-vinylphenol with 11% relative content was the most predominant pyrolytic product for lignin after steam explosion treatment. Combined with the above analysis, the structural change and pyrolysis product distribution of EHL with or without steam explosion treatment could be better understood, providing more support for the multi-functional utilization of lignin.

scholarly journals Effects on Lignin Redistribution in Eucalyptus globulus Fibres Pre-Treated by Steam Explosion: A Microscale Study to Cellulose Accessibility

Biomolecules ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 507
Author(s):  
Eduardo Troncoso-Ortega ◽  
Rosario del P. Castillo ◽  
Pablo Reyes-Contreras ◽  
Patricia Castaño-Rivera ◽  
Regis Teixeira Mendonça ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Eucalyptus Globulus ◽  
Steam Explosion ◽  
Laser Scanning ◽  
Structural Changes ◽  
Micro Particles ◽  
Cellulose Accessibility ◽  
Ft Ir ◽  
Enzymatic Accessibility ◽  
Physical And Chemical

The objective of this study was to investigate structural changes and lignin redistribution in Eucalyptus globulus pre-treated by steam explosion under different degrees of severity (S0), in order to evaluate their effect on cellulose accessibility by enzymatic hydrolysis. Approximately 87.7% to 98.5% of original glucans were retained in the pre-treated material. Glucose yields after the enzymatic hydrolysis of pre-treated material improved from 19.4% to 85.1% when S0 was increased from 8.53 to 10.42. One of the main reasons for the increase in glucose yield was the redistribution of lignin as micro-particles were deposited on the surface and interior of the fibre cell wall. This information was confirmed by laser scanning confocal fluorescence and FT-IR imaging; these microscopic techniques show changes in the physical and chemical characteristics of pre-treated fibres. In addition, the results allowed the construction of an explanatory model for microscale understanding of the enzymatic accessibility mechanism in the pre-treated lignocellulose.

scholarly journals First Evidence of “Earth Wax” Inside the Casting Molds from the Roman Era

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4259
Author(s):  
Klára Jagošová ◽  
Jan Jílek ◽  
Pavel Fojtík ◽  
Ivan Čižmář ◽  
Miroslav Popelka ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Resolution Mass Spectrometry ◽  
Intermediate Stage ◽  
Gas Chromatography Mass Spectrometry ◽  
Organic Residue ◽  
Organic Residues ◽  
Pyrolysis Gas ◽  
Main Component ◽  
Solids Analysis ◽  
Ceramic Casting

This research was focused on the analysis of material composition and organic residues present in three molds found in the Moravian region (Czech Republic) belonging to the Roman era. X-ray fluorescence spectroscopy pointed out the possible remelting of Roman objects in Barbarian territory. The analysis of organic residues retrieved from the internal part of mold #2 by pyrolysis-gas chromatography/mass spectrometry proved the presence of ozokerite wax (“earth wax”). Consequent analysis of this organic residue by Atmospheric Solids Analysis Probe–ion mobility spectrometry–high-resolution mass spectrometry (ASAP-IMS-HRMS) confirmed the presence of ceresin, the main component of ozokerite. Ceresin was also detected in a sample of the organic residue from mold #1. Note that this is the first application of ASAP-IMS-HRMS in archaeological research. The remains of earth wax in molds suggest the production of wax models as an intermediate stage for the production of lost-wax ceramic casting molds.

Activation of Enzymatic Hydrolysis Lignin by NaOH/Urea Aqueous Solution for Enhancing Its Sulfomethylation Reactivity

2018 ◽  
Vol 7 (1) ◽  
pp. 1120-1128 ◽  
Author(s):  
Binpeng Zhang ◽  
Dongjie Yang ◽  
Huan Wang ◽  
Yong Qian ◽  
JinHao Huang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Enzymatic Hydrolysis ◽  
Hydrolysis Lignin ◽  
Urea Aqueous Solution
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