Solid base catalyzed depolymerization of lignin into low molecular weight products

Chaudhary, Richa; Dhepe, Paresh L.

doi:10.1039/c6gc02701f

Cited by 137 publications

(78 citation statements)

References 38 publications

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“…It was also shown that zeolite catalysts (NaX, NaY and NaP) lead to improved yield on monomeric products compared to other catalysts like MgO or CaO. A maximum of 51 wt.% of low molecular weight products was achieved in an ethanol/water medium at 250°C [23].…”

Section: Solid-phase Catalysts For Improved Lignin Degradationmentioning

confidence: 97%

“…In native lignin, the most abundant linkage is β─O─4 ether bond, which comprises around 45-60% of all linkages within lignin, whereas hardwood lignin contains roughly 1.5 times more compared to that of softwood. In total, approximately two third of linkages are ether bonds, while the others are C─C bonds [4,11,23]. The polyphenolic aromatic structure of lignin is ideally suited to obtain aromatic molecules, either as oligomeric derivatives or as low molecular weight monomeric compounds.…”

Section: Lignin Structurementioning

confidence: 99%

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Base-Catalyzed Depolymerization of Lignin: History, Challenges and Perspectives

Rößiger¹,

Unkelbach²,

Pufky-Heinrich³

2018

Lignin - Trends and Applications

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Bio-based phenolic compounds available from lignin are promising candidates for industrial application, e.g., within polymer resins or as biogenic fuel substitutes. Among numerous conversion methods for the valorization of lignin, the base-catalyzed depolymerization (BCD) has considerable advantages with respect to other processes. By this method, lignin and lignin-containing biorefinery streams can be catalytically transferred to valuable, defined products with tailored specifications. Continuous process operation allows conversions at short residence times and, thus, enables its industrial implementation more easily due to economic reasons. This review reflects the development in the field of BCD on various types of lignin. A historical overview will be given and the principal application of the method is shown. Challenges for operations are addressed, mainly to the development of efficient and selective methods for product separation and purification of the alkylphenolic moieties and the reduction of char formation during the process. An outlook will be given by showing trends and perspectives, especially in the field of industrial applications. Here, hydrotreatment methods for refining BCD intermediates for fuel and platform chemical production are shown. Furthermore, the application of BCD for the conversion of woody biomass and black liquor is discussed.

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Section: Solid-phase Catalysts For Improved Lignin Degradationmentioning

confidence: 97%

Section: Lignin Structurementioning

confidence: 99%

Base-Catalyzed Depolymerization of Lignin: History, Challenges and Perspectives

Rößiger¹,

Unkelbach²,

Pufky-Heinrich³

2018

Lignin - Trends and Applications

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“…The importance of lignin as the biggest sustainable reservoir for aromatic rings, as not only chemical feedstocks but also material precursors, has been acknowledged broadly. Particularly, for chemical feedstocks, versatile methods have been developed, and these included reduction, oxidation, and solvolysis, and pyrolysis . The utilization of the aromatic nature to prepare aromatics from lignin is recognized as a high‐value valorization.…”

Section: Introductionmentioning

confidence: 99%

Catalytic Scissoring of Lignin into Aryl Monomers

Wang

2019

Advanced Materials

129

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Lignin is an aromatic polymer, which is the biggest and most sustainable reservoir for aromatics. The selective conversion of lignin polymers into aryl monomers is a promising route to provide aromatics, but it is also a challenging task. Compared to cellulose, lignin remains the most poorly utilized biopolymer due to its complex structure. Although harsh conditions can degrade lignin, the aromatic rings are usually destroyed. This article comprehensively analyzes the challenges facing the scissoring of lignin into aryl monomers and summarizes the recent progress, focusing on the strategies and the catalysts to address the problems. Finally, emphasis is given to the outlook and future directions of this research.

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“…Various lignin depolymerisation and conversion methods have been described in the literature, each approach having its own advantages and limitations. Examples comprise acidcatalysed [11,12], base-catalysed [13,14], thermochemical [15,16], biochemical [1,17], reductive [18,19] and oxidative [20][21][22] lignin depolymerisation. Oxidative depolymerisation, in particular, emerges as a promising route among the deconstruction strategies, as it can produce highly functionalised chemicals under relatively mild operating conditions.…”

Section: Introductionmentioning

confidence: 99%

Oxidative Depolymerisation of Lignosulphonate Lignin into Low-Molecular-Weight Products with Cu–Mn/δ-Al2O3

et al. 2019

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Lignin depolymerisation receives great attention due to the pressing need to find sustainable alternatives to fossil sources for production of fuels and chemicals. In this study, alumina-supported Cu-Mn and Ni-Mo catalysts were tested for oxidative depolymerisation of a technical lignin stream-sodium lignosulphonates-to produce valuable low-molecular-weight aromatics that may be considered for applications in the fuels and chemicals sector. The reactions were performed at elevated temperature and oxygen pressure, and the product mixtures were analysed by size exclusion chromatography, two-dimensional nuclear magnetic resonance spectroscopy and supercritical fluid chromatography mass spectrometry. The best performance was obtained with Cu-Mn/δ-Al 2 O 3 , which was thoroughly characterised before and after use by nitrogen physisorption, scanning electron microscopy, energy dispersive spectroscopy, powder X-ray diffraction, thermal gravimetric analysis, inductively coupled plasma optical emission spectrometry and X-ray photoelectron spectroscopy. Major products identified were vanillin, p-hydroxybenzaldehyde, vanillic acid and p-hydroxybenzoic acid as well as smaller aliphatic aldehydes, acids and lactones.

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Solid base catalyzed depolymerization of lignin into low molecular weight products

Abstract: We report the depolymerization of high molecular weight lignin (60 000 Da) over various recyclable solid base catalysts at 250 °C over 1 h.

Cited by 137 publications

References 38 publications

Base-Catalyzed Depolymerization of Lignin: History, Challenges and Perspectives

Base-Catalyzed Depolymerization of Lignin: History, Challenges and Perspectives

Catalytic Scissoring of Lignin into Aryl Monomers

Oxidative Depolymerisation of Lignosulphonate Lignin into Low-Molecular-Weight Products with Cu–Mn/δ-Al2O3

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