Oxidative Degradation of Dimeric Lignin Model Compounds

2001 ◽  
pp. 197-210 ◽  
Author(s):  
Carmen Canevali ◽  
Franca Morazzoni ◽  
Marco Orlandi ◽  
Bruno Rindone ◽  
Roberto Scotti ◽  
...  
Keyword(s):  
Oxidative Degradation ◽  
Model Compounds ◽  
Lignin Model Compounds ◽  
Lignin Model

Lignin reactions in oxygen delignification catalysed by Mn(II)-substituted molybdovanadophosphate polyanion

Holzforschung ◽  
2004 ◽  
Vol 58 (6) ◽  
pp. 640-649 ◽  
Author(s):  
Armindo Gaspar ◽  
Dmitry V. Evtuguin ◽  
Carlos Pascoal Neto
Keyword(s):  
Eucalyptus Globulus ◽  
Oxidative Degradation ◽  
Reaction System ◽  
Reaction Products ◽  
Oxygen Delignification ◽  
Model Compounds ◽  
Lignin Model Compounds ◽  
Qualitative And Quantitative ◽  
Lignin Model ◽  
Oxidative Delignification

Abstract The lignin oxidation in the oxygen delignification/bleaching process catalysed by Mn(II) substituted heptamolybdopentavanadophosphate polyanion (HPA-5-MnII) was studied using monomeric lignin model compounds and Eucalyptus globulus dioxane lignin adsorbed on the bleached sulphite pulp. The analysis of reaction products after lignin models oxidation in the presence HPA-5-MnII and the parent heptamolybdopentavanadophosphate polyanion (HPA-5) showed similar qualitative and quantitative patterns, indicating the identical lignin oxidative delignification mechanisms with both catalysts. The higher delignification selectivity of the pulp in the reaction system HPA-5-MnII/O2 than with HPA-5/O2 was explained by the protective effect of MnII in the heteropolyanion towards oxidative degradation of polysaccharides. The study of lignin adsorbed on bleached sulphite pulp, in the HPA-5-MnII/O2 delignification system, showed the cleavage of β-O-4 linkages as the major contribution to the lignin depolymerisation. The formation of Cα-O-polysaccharide linkages in β-O-4 structures of lignin during the delignification was observed.

scholarly journals A two-phase reaction system for selective oxidative degradation of lignin model compounds

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 6526-6538
Author(s):  
Yueying Chen ◽  
Aiguo Xue ◽  
Haomin Jiang ◽  
Yujuan Cheng ◽  
Yuan Ren ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Oxidative Degradation ◽  
Reaction System ◽  
Value Added ◽  
Bottom Phase ◽  
Phase Reaction ◽  
Model Compounds ◽  
Two Phase ◽  
Lignin Model Compounds ◽  
Lignin Model

Lignin depolymerization through an oxidation method could provide value-added products, but it is challenging in terms of recovering catalysts or separating products in time to avoid over-oxidation. In this study, a process of selectively oxidative degradation of lignin model compounds was operated in a two-phase reaction system. Lignin model compounds of 4-benzyloxyphenol (PBP) or guaiacylglycerol-β-guaiacyl ether (GGE) in a bottom phase of 1-butyl-3-methylimidazole chloride ([BMIM]Cl) ionic liquid were selectively oxidized by H2O2 in the presence of a solid acid (SO42-/Fe2O3-ZrO2), and the degradation products immediately diffused into the upper organic solvent phase (butyl acetate). In this kind of reaction system, the yield of the products was improved due to the prolonged life of ∙OH in ionic liquid, and the product selectivity was maintained due to the timely product separation, and the ionic liquid and the catalyst were easily recycled.

Lignin to Value-Added Chemical Synthesis

2020 ◽  
Vol 16 ◽  
Author(s):  
Mahdieh Sharifi ◽  
Ramyakrishna Pothu ◽  
Rajender Boddula ◽  
Inamuddin
Keyword(s):  
Ionic Liquids ◽  
Lignocellulosic Biomass ◽  
Academic Research ◽  
Power Saving ◽  
Value Added ◽  
Glycerol Ether ◽  
Model Compounds ◽  
Lignin Model Compounds ◽  
Biomass Activity ◽  
Lignin Model

Background: There is a developing demand for innovation in petroleum systems replacements. Towards this aim, lignocellulosic biomass suggested as a possible sustainable source for the manufacturing of fuels and produced chemicals. The aims of this paper are to investigate different kinds of β-O-4 lignin model compounds for the production of value-added chemicals in presence of ionic liquids. Especially, a cheap β-O-4 lignin model Guaiacol glycerol ether (GGE) (Guaifenesin) is introduced to produce valuable chemicals and novel products. Methods: Research related to chemical depolymerization of lignocellulosic biomass activity is reviewed, the notes from different methods such as thermal and microwave collected during at least 10 years. So, this collection provides a good source for academic research and it gives an efficient strategy for the manufacturing of novel value-added chemicals at an industrial scale. Results: This research presented that ionic liquid microwave-assisted is a power saving, cost efficient, fast reaction, and clean way with high selectively and purity for production of high value chemicals rather that conversional heating. Guaiacol and catechol are some of these valuable chemicals that is produced from β-O-4 lignin model compounds with high word demands that are capable to produce in industry scale. Conclusion: The β-O-4 lignin model compounds such as Guaiacol glycerol ether (GGE) (Guaifenesin) are good platform for developing food materials, perfumery, biorefinery, and pharmaceutical industry by ionic liquids-assisted lignin depolymerization method.

Insights into the electrochemical degradation of phenolic lignin model compounds in protic ionic liquid-water system

2021 ◽  
Author(s):  
Guangyong Liu ◽  
Qian Wang ◽  
Dongxia Yan ◽  
Yaqin Zhang ◽  
Chenlu Wang ◽  
...  
Keyword(s):  
Water System ◽  
Value Added ◽  
Electrochemical Degradation ◽  
Aryl Ether ◽  
Model Compounds ◽  
Protic Ionic Liquid ◽  
Lignin Model Compounds ◽  
Mild Conditions ◽  
System P ◽  
Lignin Model

Cleavage of aryl ether (Caryl-O) bonds is crucial for conversion and value-added utilization of lignin and its derivatives, but remains extremely challenging under mild conditions due to strong Caryl-O linkages....

Eco-friendly preparation of ultrathin biomass-derived Ni3S2-doped carbon nanosheets for selective hydrogenolysis of lignin model compounds in the absence of hydrogen

2021 ◽  
Vol 23 (8) ◽  
pp. 3090-3103
Author(s):  
Changzhou Chen ◽  
Dichao Wu ◽  
Peng Liu ◽  
Jing Li ◽  
Haihong Xia ◽  
...  
Keyword(s):  
Model Compounds ◽  
Lignin Model Compounds ◽  
Carbon Nanosheets ◽  
Significant Potential ◽  
Selective Hydrogenolysis ◽  
Lignin Model

Lignin is an abundant source of aromatics, and the depolymerization of lignin provides significant potential for producing high-value chemicals.

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