Effects of Two-Stage Dilute Acid Pretreatment on the Structure and Composition of Lignin and Cellulose in Loblolly Pine

Sannigrahi, Poulomi; Ragauskas, Arthur J.; Miller, Stephen J.

doi:10.1007/s12155-008-9021-y

Cited by 169 publications

(153 citation statements)

References 58 publications

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“…It has been observed (Foston and Ragauskas 2010) that the relative amount of the cellulose Ia form decreases while the relative amount of Ib allomorph increases with the duration of the process. A similar result has been reported for pretreatment of loblolly pines (Sannigrahi et al 2008). The Ia allomorph is used industrially more often than Ib because of its higher reactivity towards acetylation (Sassi et al 2000).…”

Section: Introductionsupporting

confidence: 84%

Coarse-grained model of the native cellulose $$\hbox {I}\alpha$$ and the transformation pathways to the $$\hbox {I}\beta$$ allomorph

2016

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All-atom simulations are used to derive effective parameters for a coarse-grained description of the crystalline cellulose Ia. In this description, glucose monomers are represented by the C4 atoms and non-bonded interactions within the cellulose sheets and between the sheets by effective LennardJones interactions. The parameters are determined by two methods: the Boltzmann inversion and through monitoring of the energies associated with changes of the coarse-grained degrees of freedom. We find that the stiffness-related parameters for cellulose Ia are nearly the same as for Ib allomorph. However, the non-bonded terms are placed differently and are weaker leading to an overall lower energy, and free energy, of Ib compared to Ia. We apply the coarsegrained description to determine amorphous transition states for the room-temperature conversion process between the Ia and Ib allomorphs and to characterize the interface between the crystalline forms of the allomorphs.

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Section: Introductionsupporting

confidence: 84%

Coarse-grained model of the native cellulose $$\hbox {I}\alpha$$ and the transformation pathways to the $$\hbox {I}\beta$$ allomorph

2016

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“…More precisely, line shape analysis based on a nonlinear least squares fitting analysis has been performed on this area, and it was found that the signals at 80 to 86 ppm are attributable to C-4 carbons at the accessible fibril surface and inaccessible fibril surface (Larsson et al 1999). In addition, the ratio of the area in the 86 to 92 ppm region to the total peak area in these two regions is designated as the crystallinity index (Sannigrahi et al 2008).…”

Section: Cc50mentioning

confidence: 99%

Acetic Acid Enhanced Purification of Crude Cellulose From Sugarcane Bagasse: Structural and Morphological Characterization

Bian¹,

Peng²,

Peng³

et al. 2012

BioResources

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Crude cellulose prepared from alkali-extracted sugarcane bagasse was subjected to a rapid purification treatment with a mixture of 80% acetic acid-68% nitric acid (10/1, v/v) at 120 °C for 15 min. The yields of the preparations decreased slightly from 57.3%-58.6% in the crude cellulose preparations to 50.3%-51.9% in the purified cellulose samples. The purification treatment removed large amounts of resistant hemicelluloses strongly associated to the cellulose. XRD analysis revealed that the structure of both the crude and purified cellulose was cellulose I. Compared to the crude cellulose, a slight increase in the crystallinity index of the purified cellulose was observed by FTIR, XRD, and CP/MAS 13 C NMR analyses. In addition, SEM showed that the macrofibril surface of the crude cellulose was almost free of trenches, but many terraces, steps, and kinks formed in the preparations after the purification.

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“…The spectrum obtained is shown in Fig. 4, and previously assigned signals from the literature (Sanningrahi et al 2008;Pu et al 2006) were used to assign the observed resonance. Between 80 and 100 ppm, no signals were observed, indicating low sugar content in the extracted lignin.…”

Section: Ethanol Organosolv Lignin (Eol) Recovery and Characterizationmentioning

confidence: 99%

Ethanol Organosolv Pretreatment of Typha Capensis for Bioethanol Production and Co-Products

Audu

Brosse²,

Desharnais³

et al. 2012

BioResources

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Typha capensis (TC), a highly prolific, invasive grass found in many parts of the world, is a common pest that grows in waterways, but it may be a good lignocellulosic substrate for bioethanol production. Sulfuric acid-catalyzed ethanol organosolv pretreatment was used to investigate the possibility of harnessing the benefits of both fermentable sugars and lignin by reacting at varying defined severity levels. It was observed that TC polysaccharides were particularly susceptible to hydrolysis, which was associated with the formation of a large amount of pseudo-lignin due to the degradation of sugars. Pseudo-lignin had a negative impact on enzymatic hydrolysis. At optimal conditions, the process enabled the fractionation of TC into glucan-rich solid fractions with enhanced digestibility, recovery of organosolv lignin, and easily hydrolysable hemicellulose sugars in the liquid stream of pretreatment analytes. About 68.33% of the glucan in the raw TC was recovered, and 85.23% fermentable sugars from water-soluble and enzyme-hydrolyzed pulp were attained. Up to 67% of the initial lignin in TC was extracted as ethanol organosolv lignin (EOL).

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Effects of Two-Stage Dilute Acid Pretreatment on the Structure and Composition of Lignin and Cellulose in Loblolly Pine

Cited by 169 publications

References 58 publications

Coarse-grained model of the native cellulose $$\hbox {I}\alpha$$ and the transformation pathways to the $$\hbox {I}\beta$$ allomorph

Coarse-grained model of the native cellulose $$\hbox {I}\alpha$$ and the transformation pathways to the $$\hbox {I}\beta$$ allomorph

Acetic Acid Enhanced Purification of Crude Cellulose From Sugarcane Bagasse: Structural and Morphological Characterization

Ethanol Organosolv Pretreatment of Typha Capensis for Bioethanol Production and Co-Products

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