Analyzing cellulose degree of polymerization and its relevancy to cellulosic ethanol

Hallac, Bassem B.; Ragauskas, Arthur J.

doi:10.1002/bbb.269

Cited by 262 publications

(163 citation statements)

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“…The DP of a cellulose sample was rapidly reduced to a relatively constant value upon being subjected to severe conditions hydrolyzing treatments, as in the case of the chlorite treatment, and the observed DP was 460. The initial rapid DP degradation phase corresponds to the hydrolysis of the reactive amorphous region of cellulose; while the slower plateau rate phase corresponds to the hydrolysis of the slowly reacting crystalline fraction of cellulose (Hallac and Ragauskas 2011). In the case of organosolv cellulose, the DP was 500, which indicates that the pretreatment was less aggressive than pretreatment with sodium chlorite.…”

Section: A B C Dmentioning

confidence: 99%

Agave tequilana Bagasse as Source of Cellulose Nanocrystals via Organosolv Treatment

Hernandez¹,

Romero²,

Escalante³

et al. 2018

BioResources

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Cellulose nanocrystals (CNCs) were isolated from Agave tequilana residues derived from ethanol production. Hemicelluloses and lignin extraction from agave bagasse was carried out via organosolv (ethanol/acetic) digestion followed by conventional sulfuric acid hydrolysis. The ethanol/acetic acid treatment resulted in cellulose yields of approximately 67% after lignin and ash removal. Compared to soda and sodium chlorite treatments with organosolv, the time and chemical load needed for delignification were remarkably reduced. The morphology of the cellulose fiber obtained in the three treatments was between 0.55 and 0.62 mm, with which CNC was obtained in the order of 83 to 195 nm in length. It is noteworthy that the longest cellulose fibers and nanocrystals were obtained from organosolv cellulose. The organosolv treatment led to a high purity cellulose, derived CNCs with a minimum energy consumption and mild chemical usage, and also considered the use of material streams associated with distillation processes. Thus, a viable alternative is suggested for the production of high quality CNC from widely available residual biomass that otherwise poses environmental and health-related risks.

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Section: A B C Dmentioning

confidence: 99%

Agave tequilana Bagasse as Source of Cellulose Nanocrystals via Organosolv Treatment

Hernandez¹,

Romero²,

Escalante³

et al. 2018

BioResources

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“…But organic solvents have additional effects that dilute acid pretreatments do not, including reducing the crystallinity of the recovered glucan to accelerate saccharification. Whereas dilute acid pretreatment must be followed by 4-5 days of enzymatic hydrolysis to achieve 95 % of theoretical glucan conversion, organosolv researchers have saccharified 70 % of theoretical glucan within just 8 h (Hallac and Ragauskas 2011), and achieved glucose and xylose yields greater than 90 and 50 % of theoretical (respectively) after 24 h of enzymatic hydrolysis (Cateto et al 2011). Depending on the fermentation strategy (simultaneous with saccharification or sequential) and kinetics of downstream conversion, faster hydrolysis could reduce the reactor size required during enzymatic treatment and considerably decrease both capital and operational costs.…”

Section: Organosolv Treatments Produce Lignin That Can Potentially Bementioning

confidence: 99%

A Systems View of Lignocellulose Hydrolysis

Tanjore

Richard

2015

Advances in Bioprocess Technology

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“…AQ5 Hallac and Ragauskas (2001) has been changed to Hallac and Ragauskas (2011) so that this citation matches the list. AQ6 Lourenço et al (2016) has been changed to Lourenço et al (2017) so that this citation matches the list.…”

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confidence: 99%

“…Due 527 to the conversion of cellulose I to cellulose II, the 528 spectra of CC2 and CC3 do not possess a peak at 529 1345 cm -1 (Granja and Barbosa 2001). Whether 530 phosphate groups remain in the structure of CC1 is 531 not proved by its spectrum, but their absence is not 532 confirmed either, since the most prominent band of 533 PO 4 is given at 1020 cm -1 , thus interfering with one 534 of the most noticeable bands in the spectrum of 535 cellulose (Hallac and Ragauskas 2011). Fig.…”

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Cationic cellulosic derivatives as flocculants in papermaking

et al. 2017

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7 Abstract Water-soluble cationic cellulose deriva-8 tives were synthesized by three different procedures, 9 cationizing bleached hardwood kraft pulp with (3-10 chloro-2-hydroxypropyl) trimethylammonium chlo-11 ride. The first procedure involved a previous depoly-12 merization step with orthophosphoric acid. The 13 second one consisted on dissolving cellulose in 14 NaOH/urea before cationization. For the third proce-15 dure, the reaction medium was heterogeneous since it 16 was carried out with a part of cellulose with high 17 degree of polymerization. Oppositely to the common 18 methods, cationization occurred under mild condi-19 tions. Differences among the three derivatives are 20 illustrated by X-ray diffraction patterns of pretreated 21 samples, infrared spectra, and determinations of the 22 degree of substitution, the zeta potential, the charge 23 density and the molecular weight. The performance of 24 these polyelectrolytes for the flocculation of mineral 25 fillers used in papermaking was tested by laser 26 diffraction spectrometry. The flocculant with the 27 highest degree of polymerization and charge origi-28 nated the best results, particularly when the filler used 29 was kaolin, proving that water-soluble cationic cellu-30 lose derivatives can aid in the flocculation of fillers 31 used in papermaking. On the contrary, the shortest-32 chained derivative was not effective. The results were 33 interpreted in terms of the characteristics of the 34 cellulose derivatives flocculants and of the fillers, 35 and neutralization and patching were proposed as the 36 dominant mechanisms. 37Keywords Cationization Á Cellulose Á Fillers for 38 papermaking Á Flocculation Á Laser diffraction 39 spectrometry 40 Introduction 41 Non-renewable and scarcely biodegradable polymeric 42 aids, such as cationic polyacrylamides (CPAM) or 43 polyethyleneimine (PEI), are often applied in paper 44 mills to achieve good retention of mineral fillers. The 45 particle size of these fillers is generally much smaller 46 than the wire mesh at the forming and drainage section 47 of the paper machine, and thus mechanical retention A1 Electronic supplementary material The online version of A2 this article

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Analyzing cellulose degree of polymerization and its relevancy to cellulosic ethanol

Cited by 262 publications

References 81 publications

Agave tequilana Bagasse as Source of Cellulose Nanocrystals via Organosolv Treatment

Agave tequilana Bagasse as Source of Cellulose Nanocrystals via Organosolv Treatment

A Systems View of Lignocellulose Hydrolysis

Cationic cellulosic derivatives as flocculants in papermaking

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