scholarly journals Structural changes of poplar wood lignin after supercritical pretreatment using carbon dioxide and ethanol–water as co-solvents

RSC Advances ◽  
2017 ◽  
Vol 7 (14) ◽  
pp. 8314-8322 ◽  
Author(s):  
Xing Wang ◽  
Yanzhu Guo ◽  
Jinghui Zhou ◽  
Guangwei Sun
Keyword(s):  
Carbon Dioxide ◽  
Enzymatic Hydrolysis ◽  
Structural Changes ◽  
Hydrolysis Lignin ◽  
Poplar Wood

To delineate structural changes of lignin after SCEP, enzymatic hydrolysis lignin (EHL) in poplar chips, lignin in pretreated residues (SCEP-RL), lignin in liquors (SCEP-DL) were isolated and analyzed by GPC, 13C-, 31P-, 2D-HSQC-NMR and TGA.

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.

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

Optimization of steam pretreatment conditions for enzymatic hydrolysis of poplar wood

Holzforschung ◽  
2011 ◽  
Vol 65 (4) ◽  
Author(s):  
Fokko Schütt ◽  
Jürgen Puls ◽  
Bodo Saake
Keyword(s):  
Enzymatic Hydrolysis ◽  
Raw Material ◽  
Steam Pretreatment ◽  
Alkaline Extraction ◽  
Poplar Wood ◽  
Steam Refining ◽  
Severity Factor ◽  
Short Rotation ◽  
Pretreatment Conditions ◽  
Hydrolysis Of

Abstract Steam refining was investigated as a pretreatment for enzymatic hydrolysis of poplar wood from a short rotation plantation. The experiments were carried out without debarking to use an economically realistic raw material. Steam refining conditions were varied in the range of 3–30 min and 170–220°C, according to a factorial design created with the software JMP from SAS Institute Inc., Cary, NC, USA. Predicted steaming conditions for highest glucose and xylose yields after enzymatic hydrolysis were at 210°C and 15 min. Control tests under the optimized conditions verified the predicted results. Further pretreatments without bark showed that the enzymes were not significantly inhibited by the bark. The yield of glucose and xylose was 61.9% of theoretical for the experiments with the whole raw material, whereas the yield for the experiments without bark was 63.6%. Alkaline extraction of lignin from the fibers before enzymatic hydrolysis resulted in an increase of glucose yields from mild pretreated fibers and a decrease for severe pretreated fibers. The extracted lignin had a high content of xylose of up to 14% after very mild pretreatments. On the other hand, molecular weights of the extracted lignin increased substantially after pretreatments with a severity factor above 4. Hence, alkaline extraction of the lignin seems only attractive in a narrow range of steaming conditions.

Fractionation of enzymatic hydrolysis lignin by sequential extraction for enhancing antioxidant performance

2017 ◽  
Vol 99 ◽  
pp. 674-681 ◽  
Author(s):  
Liangliang An ◽  
Guanhua Wang ◽  
Hongyu Jia ◽  
Cuiyun Liu ◽  
Wenjie Sui ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Sequential Extraction ◽  
Hydrolysis Lignin

Changes in poplar (Populus trichocarpa) wood porous structure after liquid hot water (LHW) pretreatment

2020 ◽  
Vol 112 ◽  
pp. 71-78
Author(s):  
Florentyna Akus-Szyblerg ◽  
Jan Szadkowski ◽  
Andrzej Antczak ◽  
Janusz Zawadzki
Keyword(s):  
Enzymatic Hydrolysis ◽  
Porous Structure ◽  
Populus Trichocarpa ◽  
Hot Water ◽  
Size Exclusion ◽  
Bioethanol Production ◽  
Poplar Wood ◽  
Liquid Hot Water ◽  
Exclusion Chromatography ◽  
Pretreatment Conditions

Changes in poplar (Populus trichocarpa) wood porous structure after liquid hot water (LHW) pretreatment. The aim of this research was to investigate the effect of applying different hydrothermal pretreatment conditions on the porous structure of poplar wood. Porosity is recognised as an important factor considering efficiency of an enzymatic hydrolysis as a step of bioethanol production. Native poplar wood as well as solid fractions after pretreatment performed at different temperatures (160 °C, 175 °C and 190 °C) were analysed. Porous structure was examined with an inverse size-exclusion chromatography (ISEC) method. Results indicated a significant development of the porous structure of the biomass with increasing porosity along with the growing temperature of the LHW process. The temperature of 190 °C was chosen as the most promising condition of poplar wood LHW pretreatment in terms of the efficiency of the subsequent steps of bioethanol production. The obtained results were consistent with the previous experimental data procured during analysis of the LHW pretreated poplar wood and its subsequent enzymatic hydrolysis yield.

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 Enzymatic sugar production from elephant grass and reed straw through pretreatments and hydrolysis with addition of thioredoxin-His-S

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Xianqin Lu ◽  
Can Li ◽  
Shengkui Zhang ◽  
Xiaohan Wang ◽  
Wenqing Zhang ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Pennisetum Purpureum ◽  
Commercial Application ◽  
Hydrolysis Lignin ◽  
Cellulose Content ◽  
Sugar Production ◽  
Elephant Grass ◽  
Reed Straw ◽  
Hydrolysis Yield ◽  
Hydrolysis Of

Abstract Background The bioconversion of lignocellulose to fermentable C5/C6-saccharides is composed of pretreatment and enzymatic hydrolysis. Lignin, as one of the main components, resists lignocellulose to be bio-digested. Alkali and organosolv treatments were reported to be able to delignify feedstocks and loose lignocellulose structure. In addition, the use of additives was an alternative way to block lignin and reduce the binding of cellulases to lignin during hydrolysis. However, the relatively high cost of these additives limits their commercial application. Results This study explored the feasibility of using elephant grass (Pennisetum purpureum) and reed straw (Phragmites australis), both of which are important fibrous plants with high biomass, no-occupation of cultivated land, and soil phytoremediation, as feedstocks for bio-saccharification. Compared with typical agricultural residues, elephant grass and reed straw contained high contents of cellulose and hemicellulose. However, lignin droplets on the surface of elephant grass and the high lignin content in reed straw limited their hydrolysis performances. High hydrolysis yield was obtained for reed straw after organosolv and alkali pretreatments via increasing cellulose content and removing lignin. However, the hydrolysis of elephant grass was only enhanced by organosolv pretreatment. Further study showed that the addition of bovine serum albumin (BSA) or thioredoxin with His- and S-Tags (Trx-His-S) improved the hydrolysis of alkali-pretreated elephant grass. In particular, Trx-His-S was first used as an additive in lignocellulose saccharification. Its structural and catalytic properties were supposed to be beneficial for enzymatic hydrolysis. Conclusions Elephant grass and reed straw could be used as feedstocks for bioconversion. Organosolv and alkali pretreatments improved their enzymatic sugar production; however, the increase in hydrolysis yield of pretreated elephant grass was not as effective as that of reed straw. During the hydrolysis of alkali-pretreated elephant grass, Trx-His-S performed well as additive, and its structural and catalytic capability was beneficial for enzymatic hydrolysis.

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