Reductive de-polymerization of kraft lignin for chemicals and fuels using formic acid as an in-situ hydrogen source

Huang, Shanhua; Mahmood, Nubla; Tymchyshyn, Matthew; Yuan, Zhongshun; Xu, Chunbao

doi:10.1016/j.biortech.2014.08.045

Cited by 100 publications

(75 citation statements)

References 42 publications

(35 reference statements)

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“…The use of H-donating reagents/solvents, such as formic acid and other stabilising compounds/alcohols have also been investigated in order to suppress the char formation problem and enhance the operation [20][21][22][23]. Gosselink et al [20] tackled the addition of formic acid as hydrogen donor and experienced an increase in the yield of monomeric aromatics by stabilising the aromatic radicals, up to 12% based on lignin.…”

Section: Introductionmentioning

confidence: 99%

“…Gosselink et al [20] tackled the addition of formic acid as hydrogen donor and experienced an increase in the yield of monomeric aromatics by stabilising the aromatic radicals, up to 12% based on lignin. Huang et al [22] adopted the formic acid as well as an in situ hydrogen source during the depolymerisation of kraft lignin. It was demonstrated in this study that the formic acid is a more reactive hydrogen source than external hydrogen towards the reductive depolymerisation of technical lignin streams.…”

Section: Introductionmentioning

confidence: 99%

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Continuous catalytic depolymerisation and conversion of industrial kraft lignin into low-molecular-weight aromatics

Abdelaziz

Tunå

et al. 2017

Biomass Conv. Bioref.

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Base-catalysed depolymerisation of lignin using sodium hydroxide has been shown to be an effective approach towards exploiting industrial (technical) lignins within the pulp and paper industry. In the present work, a pine kraft lignin (Indulin AT) which is precipitated from black liquor of linerboard-grade pulp was depolymerised via base catalysis to produce lowmolecular-mass aromatics without any organic solvent/capping agent in a continuous-flow reactor setup for the first time. The catalytic conversion of lignin was performed/screened at temperatures varying from 170 to 250°C, using NaOH/lignin weight ratio ≈ 1 with 5 wt% lignin solids loadings for residence times of 1, 2 and 4 min, respectively, with comprehensive characterisation of substrate and produced reaction mixtures. The products were characterised using size exclusion chromatography (SEC), nuclear magnetic resonance spectroscopy (NMR) and supercritical fluid chromatography-diode array detector-tandem mass spectrometry (SFC-MS). The optimum operating conditions for such depolymerisation appeared to be at 240°C and 30 h −1 , yielding the highest concentration of low-molecular-weight phenolics below the coking point. It was also found that the depolymerised lignin products exhibited better chemical stability during long-term storage at lower temperatures (~4°C).

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Continuous catalytic depolymerisation and conversion of industrial kraft lignin into low-molecular-weight aromatics

Abdelaziz

Tunå

et al. 2017

Biomass Conv. Bioref.

View full text Add to dashboard Cite

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“…Hydrogen donor solvents could result in the use of relatively lower working temperatures (220–300°C) than those needed for hydrotreating with gaseous hydrogen (up to 500°C) . Furthermore, hydrogen donor solvents can increase the degraded lignin yield and prevent char formation by avoiding repolymerization of reaction intermediates …”

Section: Methodsmentioning

confidence: 99%

“…In the studies using gaseous hydrogen, the use of high temperatures (>420°C) has been found to promote depolymerization into monomeric compounds like phenols or hydrocarbons . In the case of hydrogen donor solvents, low reaction temperatures (<300°C) cause only negligible effects in the lignin degradation yield . At higher temperatures, charring and repolymerization takes place, reducing the product yield from around 90% to 34%, even though the average molecular weight continues to decrease with increasing temperatures even above 300°C …”

Section: Methodsmentioning

confidence: 99%

Hydrotreating and hydrothermal treatment of alkaline lignin as technological valorization options for future biorefinery concepts: a review

Rutten

Ramírez

Posada

2016

J of Chemical Tech & Biotech

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Lignin has the potential to be a sustainable resource for producing biobased chemicals (e.g. phenols, aromatic hydrocarbons, vanillin) for multiple applications. However, given its heterogeneous and rigid structure, its efficient conversion to value‐added products remains one of the most important limiting factors for the successful viability of the biobased economy. Hydrotreating and hydrothermal treatment (including liquefaction, gasification and wet oxidation) are promising technologies that can convert lignin into biobased products. This review article provides a literature overview of how key process parameters of hydrotreating and hydrothermal treatment (operating conditions, catalysts, solvents, type of starting lignin) may influence the conversion of alkaline lignin into valuable chemical products. It was observed that low selectivity to products (and subsequent required separation and purification) and char formation are the main hurdles for effective conversion of alkaline lignin. However, experimental work in alternative catalytic systems, solvents and hydrogen sources has shown that promising opportunities exist to overcome these drawbacks. Certain catalysts (e.g. Ru/Al2O3) have been found to improve selectivity and the use of alcohol solvents (especially methanol or ethanol) as a hydrogen source has been found to improve product yields and reduce char formation at lower working temperatures and pressures. © 2016 Society of Chemical Industry

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“…[24] Notably,ethanol also acts as an effective hydrogen donor through hydride transfer of its a-hydrogen. [24] Notably,ethanol also acts as an effective hydrogen donor through hydride transfer of its a-hydrogen.…”

Section: Catalytic Deconstruction Of Ligninmentioning

confidence: 99%

Ethanol: A Promising Green Solvent for the Deconstruction of Lignocellulose

et al. 2018

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Growing energy demand, environmental impact, energy security issues, and rural economic development have encouraged the development of sustainable renewable fuels. Nonfood lignocellulosic biomass is a suitable source for sustainable energy because the biomass feedstocks are low cost, abundant, and carbon neutral. Recent thermochemical conversion studies are frequently directed at converting biomass into high-quality liquid fuel precursors or chemicals in a single step. Supercritical ethanol has been selected as a promising solvent medium to deconstruct lignocellulosic biomass because ethanol has extraordinary solubility towards lignocellulosic biomass and can be resourced from cellulosic ethanol facilities. This review provides a critical insight into both catalytic and noncatalytic strategies of lignocellulose deconstruction. In this context, the supercritical ethanol deconstruction pathways are thoroughly reviewed; GC-MS, 1D and 2D NMR spectroscopy, and elemental analysis strategies towards liquid biomass deconstruction products are also critically presented. This review aims to provide readers a broad and accurate roadmap of novel biomass to biofuel conversion techniques.

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Reductive de-polymerization of kraft lignin for chemicals and fuels using formic acid as an in-situ hydrogen source

Abstract: In this thesis work, formic acid (FA) proved to be an effective in-situ hydrogen donor for the reductive depolymerization of kraft lignin (KL). At the optimum conditions without catalysts, i.e., 300

Cited by 100 publications

References 42 publications

Continuous catalytic depolymerisation and conversion of industrial kraft lignin into low-molecular-weight aromatics

Continuous catalytic depolymerisation and conversion of industrial kraft lignin into low-molecular-weight aromatics

Hydrotreating and hydrothermal treatment of alkaline lignin as technological valorization options for future biorefinery concepts: a review

Ethanol: A Promising Green Solvent for the Deconstruction of Lignocellulose

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