Biorefinery Lignin to Renewable Chemicals via Sequential Fractionation and Depolymerization

Liang, Shaobo; Chen, Wan

doi:10.1007/s12649-016-9600-7

Cited by 13 publications

(7 citation statements)

References 30 publications

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“…They obtained lower molecular weight lignin fractions with low polydispersity by fractionation with ethyl acetate and acetone/water mixtures containing 30% or 50% acetone. A different approach was reported by Liang and Wan [39], who investigated a sequential methanol fractionation followed by hydrogenolytic depolymerization, also in the presence of H 2 O 2 , using switchgrass-based lignin-rich residues from cellulosic ethanol production. However, to our knowledge, fractionation of OKL via oxidation with H 2 O 2 has not yet been investigated.…”

Section: Introductionmentioning

confidence: 99%

Valorization of Lignin via Oxidative Depolymerization with Hydrogen Peroxide: Towards Carboxyl-Rich Oligomeric Lignin Fragments

et al. 2020

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The extraction and characterization of defined and carboxyl-rich oligomeric lignin fragments with narrow molecular weight distribution is presented herein. With regard to the well-known pulp bleaching process, oxidative lignin depolymerization was investigated using hydrogen peroxide in an aqueous alkaline solution (i.e., at T = 318 K, t = 1 h) and subsequent selective fractionation with a 10/90 (v/v) acetone/water mixture. While the weight average molecular weight (MW) of lignin in comparison to the starting material was reduced by 82% after oxidation (T = 318 K, t = 1 h, clignin = 40 g L−1, cH2O2 = 80 g L−1, cNaOH = 2 mol L−1) and subsequent solvent fractionation (T = 298 K, t = 18 h, ccleavage product = 20 g L−1), the carboxyl group (–COOH) content increased from 1.29 mmol g−1 up to 2.66 mmol g−1. Finally, the successful scale-up of this whole process to 3 L scale led to gram amounts (14% yield) of oligomeric lignin fragments with a MW of 1607 g mol−1, a number average molecular weight (MN) of 646 g mol−1, a narrow polydispersity index of 3.0, and a high –COOH content of 2.96 mmol g−1. Application of these oligomeric lignin fragments in epoxy resins or as adsorbents is conceivable without further functionalization.

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Section: Introductionmentioning

confidence: 99%

Valorization of Lignin via Oxidative Depolymerization with Hydrogen Peroxide: Towards Carboxyl-Rich Oligomeric Lignin Fragments

et al. 2020

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“…As a results, Klason lignin has been successfully depolymerized using methanol as solvent to produce bio-oil containing aromatic monomers, such as phenol, corylon, guaiacol, syringol, vanillin, etc. in high yield [87]. Hydrogenolysis of lignin had also been performed under subcritical water conditions to produce bio-oil and the product distributions had been investigated.…”

Section: Monometallic Ni-based Catalysts For Hydrogenolysis Of Ligninmentioning

confidence: 99%

Lignin Valorizations with Ni Catalysts for Renewable Chemicals and Fuels Productions

Chen

Guan

Tsang³

et al. 2019

Catalysts

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Energy and fuels derived from biomass pose lesser impact on the environmental carbon footprint than those derived from fossil fuels. In order for the biomass-to-energy and biomass-to-chemicals processes to play their important role in the loop of the circular economy, highly active, selective, and stable catalysts and the related efficient chemical processes are urgently needed. Lignin is the most thermal stable fraction of biomass and a particularly important resource for the production of chemicals and fuels. This mini review mainly focuses on lignin valorizations for renewable chemicals and fuels production and summarizes the recent interest in the lignin valorization over Ni and relevant bimetallic metal catalysts on various supports. Particular attention will be paid to those strategies to convert lignin to chemicals and fuels components, such as pyrolysis, hydrodeoxygenation, and hydrogenolysis. The review is written in a simple and elaborated way in order to draw chemists and engineers' attention to Ni-based catalysts in lignin valorizations and guide them in designing innovative catalytic materials based on the lignin conversion reaction.Catalysts 2019, 9, 488 2 of 39 processes to play their important role in the loop of the circular economy, first, the process must be energy efficient itself [2]. Second, according to Anastas's second principle [3], atom economy should be maximized and excess starting materials which will not be contained in the final product should be avoided. Thus, developing highly active and selective catalysts and enzymes is an urgent need. Current technology for lignocellulosic valorization includes biochemical fermentation, chemical and thermochemical methods using enzymes and metal catalysts, respectively. Thermochemical methods, including combustion, pyrolysis, and gasification, and chemical methods, such as hydrodeoxygenation (HDO), hydrogenolysis, and oxidative cleavage, have the advantages of higher throughputs due to the short reaction time, and thus are more suitable for commercialized and industrialized scale-up.Woody and herbaceous biomasses are large polymeric networks consisting of ca. 35-50% cellulose, 25-30% hemicellulose (glucomannan and glucuronoxylan), and 15-30% of lignin (macromolecular polymer networks with interconnected phenylpropane and phenol units with various formula, e.g., (C 31 H 34 O 11 ) n ) by weight. Lignin is one of the most thermal stable fractions and a particularly important resource for the production of chemicals and fuels. With careful design of the metal catalysts, either aromatic platform molecules, or fuels components such as naphthenes, can be preferentially produced in high yields and with high selectivity.Over the past decade, numerous monometallic and bimetallic metal catalysts using both precious and base metal precursors on various supports have been reported to successfully convert lignin into valuable products. Transition metals such as Ni (price = US$ 12.628/kg as of April 2019) are much more economically viable than precious metals...

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“…In this context, using aryl halide as C(sp2)electrophile, diverse cross-coupling strategies were developed using alkanols as the C(sp3)-partner in the presence of stoichiometric alcohol activators (Scheme 1a). 24,25 However, it is scarce to employ phenol derivatives as the C(sp2)-source in the C(sp2)-C(sp3) cross-coupling reaction, [26][27][28] and a pool of phenol derivates, mainly from lignin biomass, 13,24 has been left out. Noticeably, the use of both aryl and alkyl alcohols as two coupling partners in C(sp2)-C(sp3) bond-forming reactions is rare.…”

Section: Introductionmentioning

confidence: 99%

Photoredox/Nickel Dual Catalysis for C(sp2)-C(sp3) Cross Electrophile Coupling Reaction Using Phenols and Alcohols as the Latent Electrophile Sources

Jana,

Bhattacharya,

Dey

et al. 2024

Preprint

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Introducing alkyl groups, particularly through innovative C(sp2)-C(sp3) bond-forming methods utilizing abundant feedstocks, holds promise for expanding chemical diversity, especially in drug discovery programs. Herein, we employed biomass-derived abundant phenols and alkyl alcohols as the coupling partners for the C(sp2)-C(sp3) cross-electrophile coupling reactions. Our innovation involved activating both the coupling partner via the same activator and designing a catalytic system that activates stronger bonds while ensuring coss-selectivity. The visible-light photoredox/nickel dual catalytic systems accommodate large substrate scope tolerating diverse functional groups. Besides, both the activation and cross-coupling reaction could be performed in one pot, and the reaction could be scaled up. Preliminary mechanistic studies involving luminescence quenching, cyclic voltammetry, radical quenching, and radical clock studies elucidated the proposed reaction mechanism.

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Biorefinery Lignin to Renewable Chemicals via Sequential Fractionation and Depolymerization

Cited by 13 publications

References 30 publications

Valorization of Lignin via Oxidative Depolymerization with Hydrogen Peroxide: Towards Carboxyl-Rich Oligomeric Lignin Fragments

Valorization of Lignin via Oxidative Depolymerization with Hydrogen Peroxide: Towards Carboxyl-Rich Oligomeric Lignin Fragments

Lignin Valorizations with Ni Catalysts for Renewable Chemicals and Fuels Productions

Photoredox/Nickel Dual Catalysis for C(sp2)-C(sp3) Cross Electrophile Coupling Reaction Using Phenols and Alcohols as the Latent Electrophile Sources

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