Bond cleavage of lignin model compounds into aromatic monomers using supported metal catalysts in supercritical water

Yamaguchi, Aritomo; Mimura, Naoki; Shirai, Masayuki; Sato, Osamu

doi:10.1038/srep46172

Cited by 44 publications

(33 citation statements)

References 40 publications

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“…Aromatic compounds like benzoate [12], p-cresol [5], or phenylacetate (PAA) [13,14] are associated with process instability and disturbances [9]. One major source for aromatic compounds are lignocellulosic materials often found in municipal and agricultural waste materials [15]. Their common characteristic is a benzene ring, which is thermodynamically very stable [16].…”

Section: Introductionmentioning

confidence: 99%

Microbial and Phenyl Acid Dynamics during the Start-up Phase of Anaerobic Straw Degradation in Meso- and Thermophilic Batch Reactors

et al. 2019

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Aromatic compounds like phenyl acids derived from lignocellulose degradation have been suspected to negatively influence biogas production processes. However, results on this topic are still inconclusive. To study phenyl acid formation in batch reactors during the start-up phase of anaerobic degradation, different amounts of straw from grain were mixed with mesophilic and thermophilic sludge, respectively. Molecular biological parameters were assessed using next-generation sequencing and qPCR analyses. Metagenomic predictions were done via the program, piphillin. Methane production, concentrations of phenylacetate, phenylpropionate, phenylbutyrate, and volatile fatty acids were monitored chromatographically. Methanosarcina spp. was the dominant methanogen when high straw loads were effectively degraded, and thus confirmed its robustness towards overload conditions. Several microorganisms correlated negatively with phenyl acids; however, a negative effect, specifically on methanogens, could not be proven. A cascade-like increase/decrease from phenylacetate to phenylpropionate, and then to phenylbutyrate could be observed when methanogenesis was highly active. Due to these results, phenylacetate was shown to be an early sign for overload conditions, whereas an increase in phenylbutyrate possibly indicated a switch from degradation of easily available to more complex substrates. These dynamics during the start-up phase might be relevant for biogas plant operators using complex organic wastes for energy exploitation.

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Section: Introductionmentioning

confidence: 99%

Microbial and Phenyl Acid Dynamics during the Start-up Phase of Anaerobic Straw Degradation in Meso- and Thermophilic Batch Reactors

et al. 2019

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“…Due to the highly aromatic structure of lignin, different processes have been developed that break down lignin molecules to produce other valuable aromatic chemicals, such as benzene, toluene, xylene, styrene, phenols, cyclohexane, aromatic aldehydes, vanillin, and vanillic acid (da Silva et al, 2009;Varanasi et al, 2013;Yamaguchi et al, 2017). Since lignin is a polyol, different synthesis techniques have also been used to study the effect of lignin incorporation on the properties of biodegradable polymer materials.…”

Section: Ligninmentioning

confidence: 99%

The Effect of Plant Source on the Properties of Lignin-Based Polyurethanes

2018

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This work increases our understanding of the effect of plant source on the mechanical and morphological properties of lignin-based polyurethanes (PUs). Lignin is a polymer that is synthesized inside the plant cell wall and can be used as a polyol to synthesize PUs. The specific aromatic structure of the lignin is heavily reliant on the plant source from which it is extracted. These results show that the mechanical properties of ligninbased PUs differ based on lignin's plant source. The morphology of lignin-based PUs was examined using atomic force microscopy and scanning electron microscopy and the mechanical properties of lignin-based PU samples were measured using dynamic mechanical analysis and shore hardness (Type A). The thermal analysis and morphology studies demonstrate that all PUs prepared form a multiphase morphology. In these PUs, better mixing was observed in the wheat straw lignin PU samples leading to higher moduli than in the hardwood lignin and softwood lignin PUs whose morphology was dominated by larger aggregates. Independent of the type of the lignin used, increasing the fraction of lignin increased the rigidity of PU. Among the different types of lignin studied, PU with wheat straw soda lignin exhibited storage moduli ~2-fold higher than those of PUs incorporating other lignins. This study also showed that during synthesis all hydroxyl groups in the lignin are not available to react with isocyanates, which alters the number of cross-links formed within the PU and impacts the mechanical properties of the material.

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“…It provides an alternative approach to addressing renewable fuel sources and their associated environmental issues that converting renewable lignocellulosic biomass to value-added chemicals and biofuels by catalyzing (Son and Toste, 2010 ; Ma et al, 2018 ; Rinesch and Bolm, 2018 ; Gao et al, 2019 ; Liu et al, 2019 ). In general, the composition of the biomass, lignocellulose, is mainly composed of cellulose, lignin, and hemicellulose (Son and Toste, 2010 ; Yamaguchi et al, 2017 , 2020 ; Rinesch and Bolm, 2018 ). Although the degradation and utilization of lignin is attractive, the development of reliable methods to access the aforementioned materials is still underdeveloped (Yamaguchi et al, 2020 ).…”

Section: Introductionmentioning

confidence: 99%

Catalytic Cleavage of the C-O Bond in 2,6-dimethoxyphenol Without External Hydrogen or Organic Solvent Using Catalytic Vanadium Metal

Xie

Tan

et al. 2020

Front. Chem.

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Hydrogenolysis of the CO bonds in lignin, which promises to be able to generate fuels and chemical feedstocks from biomass, is a particularly challenging and important area of investigation. Herein, we demonstrate a vanadium-catalyzed cleavage of a lignin model compound (2,6-dimethoxyphenol). The impact of the catalyst in the context of the temperature, reaction time, and the solvent, was examined for the cleavage of the methyl ethers in 2,6-dimethoxyphenol. In contrast to traditional catalytic transfer hydrogenolysis, which requires high pressure hydrogen gas or reductive organic molecules, such as an alcohol and formic acid, the vanadium catalyst demonstrates superior catalytic activity on the cleavage of the CO bonds using water as a solvent. For example, the conversion of 2,6-dimethoxyphenol is 89.5% at 280 • C after 48 h using distilled water. Notably, the vanadium-catalyzed cleavage of the CO bond linkage in 2,6-dimethoxyphenol affords 3-methoxycatechol, which undergoes further cleavage to afford pyrogallol. This work is expected to provide an alternative method for the hydrogenolysis of lignin and related compounds into valuable chemicals in the absence of external hydrogen and organic solvents.

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Bond cleavage of lignin model compounds into aromatic monomers using supported metal catalysts in supercritical water

Cited by 44 publications

References 40 publications

Microbial and Phenyl Acid Dynamics during the Start-up Phase of Anaerobic Straw Degradation in Meso- and Thermophilic Batch Reactors

Microbial and Phenyl Acid Dynamics during the Start-up Phase of Anaerobic Straw Degradation in Meso- and Thermophilic Batch Reactors

The Effect of Plant Source on the Properties of Lignin-Based Polyurethanes

Catalytic Cleavage of the C-O Bond in 2,6-dimethoxyphenol Without External Hydrogen or Organic Solvent Using Catalytic Vanadium Metal

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