Upgrading of lignin-derived bio-oils by catalytic hydrodeoxygenation

Saidi, Majid; Samimi, Fereshteh; Karimipourfard, Dornaz; Nimmanwudipong, Tarit; Gates, Bruce C.; Rahimpour, Mohammad Reza

doi:10.1039/c3ee43081b

Cited by 829 publications

(650 citation statements)

References 150 publications

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“…In the first case, secondary cell wall-specific promoters (such as promoters of secondary cell wall cellulose biosynthesis or lignin-specific genes; Petrik et al, 2016) could be used to drive the expression of silencing constructs. The thermal conversion of lignocellulosics to renewable gas and bio-oils has been heavily researched, and the benefits for industrial implementation have become clear (Yaman, 2004;Saidi et al, 2014). Feedstocks with high lignin levels might be a promising source of aromatic/phenolic compounds to produce bio-based products from lignin, as proposed in a lignin-first biorefinery approach ( Van den Bosch et al, 2015;Rinaldi et al, 2016) and as demonstrated recently with high-level monomer production via hydrogenolysis (Shuai et al, 2016).…”

Section: Discussionmentioning

confidence: 99%

Silencing CHALCONE SYNTHASE in Maize Impedes the Incorporation of Tricin into Lignin and Increases Lignin Content

et al. 2016

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Lignin is a phenolic heteropolymer that is deposited in secondary-thickened cell walls, where it provides mechanical strength. A recent structural characterization of cell walls from monocot species showed that the flavone tricin is part of the native lignin polymer, where it is hypothesized to initiate lignin chains. In this study, we investigated the consequences of altered tricin levels on lignin structure and cell wall recalcitrance by phenolic profiling, nuclear magnetic resonance, and saccharification assays of the naturally silenced maize (Zea mays) C2-Idf (inhibitor diffuse) mutant, defective in the CHALCONE SYNTHASE Colorless2 (C2) gene. We show that the C2-Idf mutant produces highly reduced levels of apigenin-and tricin-related flavonoids, resulting in a strongly reduced incorporation of tricin into the lignin polymer. Moreover, the lignin was enriched in b-b and b-5 units, lending support to the contention that tricin acts to initiate lignin chains and that, in the absence of tricin, more monolignol dimerization reactions occur. In addition, the C2-Idf mutation resulted in strikingly higher Klason lignin levels in the leaves. As a consequence, the leaves of C2-Idf mutants had significantly reduced saccharification efficiencies compared with those of control plants. These findings are instructive for lignin engineering strategies to improve biomass processing and biochemical production.

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Section: Discussionmentioning

confidence: 99%

Silencing CHALCONE SYNTHASE in Maize Impedes the Incorporation of Tricin into Lignin and Increases Lignin Content

et al. 2016

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“…Accordingly, the extent of hydrogen incorporation in these fixed bed systems will be limited by thermodynamic equilibrium, with greater hydrogen incorporation achieved in fixed bed reactor #2 due to its lower operating temperature. The lower operating pressure of the ex situ upgrading reactors, chosen to maintain the pyrolysis products in the vapor phase, will also limit the extent of hydrogenation, as compared to typical hydrotreating conditions (50-100 bar) [17,18]. Deoxygenation can be achieved through decarbonylation (removal of oxygen as CO), decarboxylation (removal of oxygen as CO 2 ), hydrodeoxygenation (encompassing both direct hydrogenolysis and hydrogenation-dehydration; removal of oxygen as H 2 O), and certain C-C coupling reactions (discussed below) [12,17,18].…”

Section: Reaction Chemistry and Catalyst Optionsmentioning

confidence: 99%

“…The lower operating pressure of the ex situ upgrading reactors, chosen to maintain the pyrolysis products in the vapor phase, will also limit the extent of hydrogenation, as compared to typical hydrotreating conditions (50-100 bar) [17,18]. Deoxygenation can be achieved through decarbonylation (removal of oxygen as CO), decarboxylation (removal of oxygen as CO 2 ), hydrodeoxygenation (encompassing both direct hydrogenolysis and hydrogenation-dehydration; removal of oxygen as H 2 O), and certain C-C coupling reactions (discussed below) [12,17,18]. Decarbonylation and decarboxylation proceed through cleavage of C-C bonds, thus reducing oxygen content at the expense of carbon efficiency, with decarboxylation being preferred as two oxygen atoms are removed per carbon atom.…”

Section: Reaction Chemistry and Catalyst Optionsmentioning

confidence: 99%

“…Research is ongoing to develop catalysts that can perform these transformations under the process conditions outlined in this study. Accordingly, a number of excellent reviews have been published in the last 3-4 years discussing potential catalysts for biomass pyrolysis vapor upgrading, highlighting the key advantages and disadvantages of the different materials, and identifying reaction mechanisms [12,17,18,48,49]. As the scope of this work is to evaluate a process design for ex situ catalytic fast pyrolysis incorporating hot gas filtration and fixed bed systems, a thorough discussion of catalyst types and functionalities is not included; however, a few catalyst types/formulations are highlighted as they are explicitly considered in the process design (Table 3).…”

Section: Reaction Chemistry and Catalyst Optionsmentioning

confidence: 99%

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Conceptual Process Design and Techno-Economic Assessment of Ex Situ Catalytic Fast Pyrolysis of Biomass: A Fixed Bed Reactor Implementation Scenario for Future Feasibility

Dutta

Schaidle

Humbird³

et al. 2015

Top Catal

103

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Ex situ catalytic fast pyrolysis of biomass is a promising route for the production of fungible liquid biofuels. There is significant ongoing research on the design and development of catalysts for this process. However, there are a limited number of studies investigating process configurations and their effects on biorefinery economics. Herein we present a conceptual process design with techno-economic assessment; it includes the production of upgraded bio-oil via fixed bed ex situ catalytic fast pyrolysis followed by final hydroprocessing to hydrocarbon fuel blendstocks. This study builds upon previous work using fluidized bed systems, as detailed in a recent design report led by the National Renewable Energy Laboratory (NREL/ TP-5100-62455); overall yields are assumed to be similar, and are based on enabling future feasibility. Assuming similar yields provides a basis for easy comparison and for studying the impacts of areas of focus in this study, namely, fixed bed reactor configurations and their catalyst development requirements, and the impacts of an inline hot gas filter. A comparison with the fluidized bed system shows that there is potential for higher capital costs and lower catalyst costs in the fixed bed system, leading to comparable overall costs. The key catalyst requirement is to enable the effective transformation of highly oxygenated biomass into hydrocarbons products with properties suitable for blending into current fuels. Potential catalyst materials are discussed, along with their suitability for deoxygenation, hydrogenation and C-C coupling chemistry. This chemistry is necessary during pyrolysis vapor upgrading for improved bio-oil quality, which enables efficient downstream hydroprocessing; C-C coupling helps increase the proportion of diesel/jet fuel range product. One potential benefit of fixed bed upgrading over fluidized bed upgrading is catalyst flexibility, providing greater control over chemistry and product composition. Since this study is based on future projections, the impacts of uncertainties in the underlying assumptions are quantified via sensitivity analysis. This analysis indicates that catalyst researchers should prioritize by: carbon efficiency [ catalyst cost [ catalyst lifetime, after initially testing for basic operational feasibility.

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“…The catalysts should strike a compromise between activity, selectivity and stability. In particular, the selection of a stable support that can withstand the supercritical conditions constitutes a challenge due to lack of stability in the presence of hot compressed water [14,15].…”

Section: Introductionmentioning

confidence: 99%

Bio-oil upgrading in supercritical water using Ni-Co catalysts supported on carbon nanofibres

Remón

Arauzo

García

et al. 2016

Fuel Processing Technology

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This work addresses the preparation, characterisation and screening of different Ni-Co catalysts supported on carbon nanofibres (CNFs) for use in the upgrading of bio-oil in supercritical water. The aim is to improve the physicochemical properties of bio-oil so that it can be used as a fuel. The CNFs were firstly oxidised in HNO 3 and afterwards subjected to a thermal treatment to selectively modify their surface chemistry prior to the incorporation of the metal active phase (Ni-Co). The CNFs and the supported catalysts were thoroughly characterised by several techniques, which allowed a relationship to be established between the catalyst properties and the upgrading results.The use of Ni-Co/CNFs for bio-oil upgrading in supercritical water (SCW) significantly improved the properties of the original feedstock. In addition, the thermal treatment to which the fibres were subjected exerted a significant influence on their catalyticproperties. An increase in the severity of the thermal treatment led to a substantial reduction in the oxygen content of the CNFs, mainly due to the removal of the less 2 stable oxygen surface groups, which allowed their surface polarity to decrease. This decrease resulted in less formation of solid products. However, it also reduced the H/C and increased the O/C ratios of the upgraded liquid. Therefore, a compromise between the yield and the properties of the upgraded bio-oil was achieved with a Ni-Co supported on a CNF with a moderate amount of oxygen surface groups.

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Upgrading of lignin-derived bio-oils by catalytic hydrodeoxygenation

Cited by 829 publications

References 150 publications

Silencing CHALCONE SYNTHASE in Maize Impedes the Incorporation of Tricin into Lignin and Increases Lignin Content

Silencing CHALCONE SYNTHASE in Maize Impedes the Incorporation of Tricin into Lignin and Increases Lignin Content

Conceptual Process Design and Techno-Economic Assessment of Ex Situ Catalytic Fast Pyrolysis of Biomass: A Fixed Bed Reactor Implementation Scenario for Future Feasibility

Bio-oil upgrading in supercritical water using Ni-Co catalysts supported on carbon nanofibres

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