Batch microreactor studies of lignin and lignin model compound depolymerization by bases in alcohol solvents

Miller, James E.; Evans, Lindsey; Littlewolf, A.; Trudell, Daniel E.

doi:10.1016/s0016-2361(99)00072-1

Cited by 241 publications

(191 citation statements)

References 9 publications

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“…[90,91] The first step in this process involves base-catalyzed depolymerization of lignin with NaOH and methanol or ethanol as solvent at 320 8C and 120 atm. [90,92] The liquid products are separated from the solids and neutralized with sulfuric acid, and the lignin is extracted in a toluene stream. The lignin, which contains mono-, di-, and polyalkylated phenols and benzenes with minor amounts of alkyoxyphenols and alkyoxybenzene, is then separated from the toluene stream and fed to the hydroprocessing unit.…”

Section: Hydrotreating Of Ligninmentioning

confidence: 99%

Synergies between Bio‐ and Oil Refineries for the Production of Fuels from Biomass

2007

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As petroleum prices continue to increase, it is likely that biofuels will play an ever‐increasing role in our energy future. The processing of biomass‐derived feedstocks (including cellulosic, starch‐ and sugar‐derived biomass, and vegetable fats) by catalytic cracking and hydrotreating is a promising alternative for the future to produce biofuels, and the existing infrastructure of petroleum refineries is well‐suited for the production of biofuels, allowing us to rapidly transition to a more sustainable economy without large capital investments for new reaction equipment. This Review discusses the chemistry, catalysts, and challenges involved in the production of biofuels.

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Section: Hydrotreating Of Ligninmentioning

confidence: 99%

Synergies between Bio‐ and Oil Refineries for the Production of Fuels from Biomass

2007

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“…Aryl-alkyl (b-O-4) ether bonds in lignin are easier to cleave than C-C bonds in basecatalyzed lignin depolymerisation [54], although mineral bases typically require harsh reaction temperatures of around 340°C [55][56][57], which can generate significant gaseous products via side reactions and consequent lower monomeric hydrocarbon yields [58]. In base-catalyzed depolymerization, the choice of lignin influences the yield of bio-oil, but not the resulting composition [59]; however, the use of mineral bases may necessitate neutralisation of the subsequent bio-oil, in addition to reactor corrosion.…”

Section: Base-catalyzed Depolymerizationmentioning

confidence: 99%

“…Considering that lignin depolymerization can be performed successfully with homogeneous base catalysts, such as KOH and NaOH, with conversions reaching 95 % [55], [60], and that heterogeneous Ni catalysts are able to cleave C-O bonds [67], Sturgeon et al proposed a combination of these active components [19]. A 5 wt% Ni supported on a MgAl hydrotalcite (a solid base catalyst employed widely for lipid transesterification to biodiesel [68][69][70]) was shown to depolymerise a lignin model compound, 2-phenoxy-1-phenethanol, and ball-milled lignin extracted from corn stover, into low molecular weight alkyl aromatics; interestingly, nickel nanoparticles present on the (likely external) hydrotalcite surface required no activation with H 2 prior to their catalytic application, suggesting that the active species was a mixed valence nickel oxide.…”

Section: Base-catalyzed Depolymerizationmentioning

confidence: 99%

Heterogeneously catalyzed lignin depolymerization

Pineda

Lee

2016

Appl Petrochem Res

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Biomass offers a unique resource for the sustainable production of bio-derived chemical and fuels as drop-in replacements for the current fossil fuel products. Lignin represents a major component of lignocellulosic biomass, but is particularly recalcitrant for valorization by existing chemical technologies due to its complex crosslinking polymeric network. Here, we highlight a range of catalytic approaches to lignin depolymerisation for the production of aromatic bio-oil and monomeric oxygenates.

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“…Lignin can be converted into polyols via hydrolysis in the presence of basic catalysts (Mahmood et al 2013), and the treatment with organic solvents (Jin et al 2011) or supercritical methanol and ethanol (Miller et al 1999). The methods of cellulose liquefaction are based on cellulose hydrogenolysis or hydrolysis assisted by acids, enzymes, ionic liquids or hot steam (Baek et al 2012;Liu et al 2012).…”

Section: Introductionmentioning

confidence: 99%

Biopolyols obtained via crude glycerol-based liquefaction of cellulose: their structural, rheological and thermal characterization

et al. 2016

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In this work lignocellulose biomass liquefaction was used to produce biopolyols suitable for the manufacturing of rigid polyurethane foams. In order to better evaluate the mechanism of the process, pure cellulose was applied as a raw material. The effect of time and temperature on the effectiveness of liquefaction and the parameters of resulting biopolyols were characterized. The prepared materials were analyzed in terms of their chemical structure, rheology, thermal and oxidative stability, and basic physical and mechanical properties that are important from the point of view of polyurethane manufacturing. The optimal parameters for the biopolyol production with a 94 % yield were achieved at 150°C for a 6-h reaction duration. The obtained polyols were characterized by the hydroxyl number of 643 mg KOH/g and enhanced thermal and oxidative stability compared to the polyols obtained at lower temperatures, which is associated with the altered mechanism of liquefaction. The results of rheological tests, analyzed with the use of Ostwald-de Waele and Herschel Bulkley models, revealed that the prepared biopolyols can be classified as pseudoplastic fluids with the viscosity values similar to those of commercially available products. Rigid foams obtained via partial substitution of petrochemical polyol with prepared biobased one were characterized by slightly increased apparent density and average cell size comparing to unmodified materials. The best mechanical performance was observed for the sample containing 35 wt% of biopolyol in the polyol mixture, which indicates a synergistic effect between the applied polyols. The applied modification delayed thermal degradation of foams due to changes in thermal decomposition process. In conclusion, the presented work confirms that lignocellulose biomass liquefaction can be successfully applied as a manufacturing method of polyols later used in the production of polyurethanes.

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Batch microreactor studies of lignin and lignin model compound depolymerization by bases in alcohol solvents

Cited by 241 publications

References 9 publications

Synergies between Bio‐ and Oil Refineries for the Production of Fuels from Biomass

Synergies between Bio‐ and Oil Refineries for the Production of Fuels from Biomass

Heterogeneously catalyzed lignin depolymerization

Biopolyols obtained via crude glycerol-based liquefaction of cellulose: their structural, rheological and thermal characterization

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