Acid Extraction of the Alkaline Wood Pulps (Kraft or SODA/AQ) Before or During Bleaching Reason and Opportunity

Marechal, Alain

doi:10.1080/02773819308020517

Cited by 20 publications

(9 citation statements)

References 4 publications

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“…Maréchal first proposed to apply an acid hydrolysis stage on alkaline hardwood kraft pulp and found the decreases in kappa number and the degradation products of HexA in acid effluents. [10] Vuorinen proposed that a hot acid hydrolysis stage can be used, which he has shown can selectively remove nearly 90% of HexA in birch kraft pulps. [11] In addition to useful HexA removal, Andrew's work showed a fringe benefit: there was some Klason lignin removal during acid hydrolysis.…”

Section: Introductionmentioning

confidence: 99%

The Impact of Xylanase and Hot Acid Pretreatment on HexAs in Eucalyptus Kraft Pulp Bleaching

Meng

et al. 2015

Journal of Wood Chemistry and Technology

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The influence of the presence of hexenuronic acid (HexA) in eucalyptus kraft pulp on the efficiency of D 0 EpD 1 was investigated by separately using both commercial cellulase-free xylanase and hot acid pretreatments. In comparison to the xylanase pretreatment, the hot acid pretreatment was more than four-fold effective in removing the HexAs (61%) and concomitantly reduced the kappa number, but resulted in lower viscosity. After subsequent D 0 EpD 1 bleaching, the final brightness and its stability were improved remarkably, especially under xylanase pretreatment. At the same brightness of 85% ISO, the xylanase pretreatment reduced the consumption of active chlorine (35.6%) more than the acid pretreatment did (27.5%). The total relative active chlorine savings for the xylanase pretreatment over the acid pretreatment was therefore nearly 23%. The HexA component can be removed considerably in both D 0 and D 1 stages during the D 0 EpD 1 bleaching sequence, while only slightly in the Ep stage. The use of xylanase and acid pretreatment both resulted in insignificant physical strength losses for the bleached pulps.

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Section: Introductionmentioning

confidence: 99%

The Impact of Xylanase and Hot Acid Pretreatment on HexAs in Eucalyptus Kraft Pulp Bleaching

Meng

et al. 2015

Journal of Wood Chemistry and Technology

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“…Results obtained from laboratory studies and mill trials indicate savings in total active chlorine of about 20 to 25% (Bim and Franco 2000;Senior and Hamilton 1992;1992a,b;1993;Senior et al 1999;Shobhit et al 2005;Tolan and Canovas 1992). Xylanase enzymes hydrolyze the xylan re-precipitated onto the fiber surface and therefore improve fiber permeability to bleaching reagents (Kantelinen et al 1993).…”

Section: Effect Of Xylanases On Bleaching Chemical Consumptionmentioning

confidence: 98%

“…However, in extreme temperature and alkali dosage conditions, these composites, as well as other polysaccharides, suffer alkaline hydrolysis and are degraded. Hexenuronic acid also suffers hydrolysis under acidic conditions as it is vulnerable to the attack of electrophilic oxidants (Marechal et al 1993). Since the discovery of hexenuronic acid structures in kraft pulps (Vuorinen et al 1999), several strategies have been proposed for removing the composites from the pulp during the bleaching phase, which are based on an acid hydrolysis stage conducted at a temperature of about 80 to 100 °C and a pH of about 3.0 (Almeida 2004).…”

Section: Effect Of Xylanase On Hexeneuronic Acid Contentmentioning

confidence: 99%

Applicability of Microbial Xylanases in Paper Pulp Bleaching: A Review

Gangwar

Prakash

2014

BioResources

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“…Removal of 4-O-methyl--D-glucuronic acid groups, which exist in the xylan structure as part of the arabinoglucuronoxylan in softwood and glucuronoxylan in hardwood, occurs during alkaline pulping of wood. This leads to the formation of 2-O-(4-deoxy--L-threo-hex-4-enopyranosyluronic acid)-Dxylitol (hexenuronic acid-D-xylitol); this structure is commonly referred to as hexenuronic acid and abbreviated as HexA [7,32,53]. HexA reacts with numerous bleaching agents, such as ozone, chlorine dioxide or peracids [3,6,55], and thus consumes these expensive and environmentally malevolent chemicals.…”

Section: Environmental Burdens Of Pulpingmentioning

confidence: 99%

Flexible biorefinery for producing fermentation sugars, lignin and pulp from corn stover

Kadam

Chin

Brown

2008

J Ind Microbiol Biotechnol

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A new biorefining process is presented that embodies green processing and sustainable development. In the spirit of a true biorefinery, the objective is to convert agricultural residues and other biomass feedstocks into value-added products such as fuel ethanol, dissolving pulp, and lignin for resin production. The continuous biomass fractionation process yields a liquid stream rich in hemicellulosic sugars, a lignin-rich liquid stream, and a solid cellulose stream. This paper generally discusses potential applications of the three streams and specifically provides results on the evaluation of the cellulose stream from corn stover as a source of fermentation sugars and specialty pulp. Enzymatic hydrolysis of this relatively pure cellulose stream requires significantly lower enzyme loadings because of minimal enzyme deactivation from nonspecific binding to lignin. A correlation was shown to exist between lignin removal efficiency and enzymatic digestibility. The cellulose produced was also demonstrated to be a suitable replacement for hardwood pulp, especially in the top ply of a linerboard. Also, the relatively pure nature of the cellulose renders it suitable as raw material for making dissolving pulp. This pulping approach has significantly smaller environmental footprint compared to the industry-standard kraft process because no sulfur- or chlorine-containing compounds are used. Although this option needs some minimal post-processing, it produces a higher value commodity than ethanol and, unlike ethanol, does not need extensive processing such as hydrolysis or fermentation. Potential use of low-molecular weight lignin as a raw material for wood adhesive production is discussed as well as its use as cement and feed binder. As a baseline application the hemicellulosic sugars captured in the hydrolyzate liquor can be used to produce ethanol, but potential utilization of xylose for xylitol fermentation is also feasible. Markets and values of these applications are juxtaposed with market penetration and saturation.

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Acid Extraction of the Alkaline Wood Pulps (Kraft or SODA/AQ) Before or During Bleaching Reason and Opportunity

Cited by 20 publications

References 4 publications

The Impact of Xylanase and Hot Acid Pretreatment on HexAs in Eucalyptus Kraft Pulp Bleaching

The Impact of Xylanase and Hot Acid Pretreatment on HexAs in Eucalyptus Kraft Pulp Bleaching

Applicability of Microbial Xylanases in Paper Pulp Bleaching: A Review

Flexible biorefinery for producing fermentation sugars, lignin and pulp from corn stover

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