Structural constraints affecting the initial enzymatic hydrolysis of recycled paper

Nazhad, Mousa M.; Ramos, Luiz Pereira; Paszner, L.; Saddler, John N.

doi:10.1016/0141-0229(94)00057-x

Cited by 66 publications

(38 citation statements)

References 15 publications

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“…6. Refining of unprinted newspaper fibers resulted in considerably higher surface areas, which have been reported to determine the rate and degree of hydrolysis of the substrate (Nazhad et al 1995). The sugar conversion at 4 FPU/g was improved by refining to 43% and 56% using 10,000 revolutions of PFI.…”

Section: Effect Of Mechanical Refining On Enzymatic Hydrolysismentioning

confidence: 95%

Enzymatic Hydrolysis of Pretreated Newspaper Having High Lignin Content for Bioethanol Production

et al. 2015

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Recovered papers are suitable biomass sources for conversion into sugars that can be used in bioethanol production. However, paper materials with a high lignin content have been found to be recalcitrant to enzymatic hydrolysis. To address this issue, several biomass pretreatment methods were employed to evaluate their efficiency on the conversion of newspaper with high lignin content to sugar. Autohydrolysis, a hot water treatment, was identified to adversely affect sugar conversion, presumably as a result of pore collapse under high-temperature pretreatment. Flexo ink, used in newspaper printing, had no effect on the enzymatic hydrolysis, with or without autohydrolysis. The ink was still detachable after autohydrolysis, as measured by hyperwashing. Compared to untreated newspaper, separate treatments of either mechanical refining or a non-ionic surfactant (sorbitan polyoxyethylene monooleate) improved the sugar conversion by 10% at enzyme dosages of 2 and 8 FPU/g substrate. The combination of both refining and surfactant resulted in the highest sugar conversions, i.e., 46.3%, 56.7%, and 64.1% at 2, 4, and 8 FPU/g enzyme dosages, respectively. Oxidative pretreatment (oxygen, 100 °C) marginally increased the sugar conversion, whereas alkaline and green liquor (NaCO3 and Na2S) pretreatments (at 160 °C) had either no effect or decreased the sugar conversion. Based on the results of the pretreatments, higher pretreatment temperatures of newsprint negatively impacted subsequent enzyme hydrolysis.

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Section: Effect Of Mechanical Refining On Enzymatic Hydrolysismentioning

confidence: 95%

Enzymatic Hydrolysis of Pretreated Newspaper Having High Lignin Content for Bioethanol Production

et al. 2015

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“…It is due to the irreversible alterations in the cells structure during the drying (Oksanen et al 1997;Kim et al 2000;Diniz et al 2004). The worse properties of the recycled fibres in comparison with the primary fibres can be caused by hornification but also by the decrease of the hydrophilic properties of the fibres surface during the drying due to the redistribution or migration of resin and fat acids to the surface (Nazhad & Paszner 1994;Nazhad 2005). Okayama (2002) observed the enormous increase of the contact angle with water which is related to the fiber inactivation at the recycling.…”

Section: Paper Recyclingmentioning

confidence: 99%

“…However, there were very few investigations into the effect of recycling on sheet properties until late 1960's. From then until the late 1970's, a considerable amount of work was carried out to identify the effects of recycling on pulp properties and the cause of these effects (Nazhad 2005;Nazhad & Paszner 1994). In the late 1980's and early 1990's, recycling issues have emerged stronger than before due to the higher cost of landfills in developed countries and an evolution in human awareness.…”

Section: Introductionmentioning

confidence: 99%

“…Howard & Bichard (1992) reported that beaten bleached kraft pulp produced handsheets which were bulky and weak in tensile and burst strengths by handsheet recycling. This behaviour could be explained by the reduction in re-swelling capability or the reduction in flexibility of rewetted pulp fibers due to fiber hornification and, possibly, by fines loss during recycling processes, which decrease both total bonding area and the strength of paper (Howard 1995;Nazhad & Paszner 1994;Nazhad et al 1995;Khantayanuwong et al 2002;Kim et al 2000). Paper recycling is increasingly important for the sustainable development of the paper industry as an environmentally friendly sound.…”

Section: Introductionmentioning

confidence: 99%

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The Effects of Paper Recycling and its Environmental Impact

Čabalová¹,

Kačík²,

Geffert³

et al. 2011

Environmental Management in Practice

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“…There is no doubt that the initial hydrolysis rate or the final hydrolysis yield is influenced by physicochemical structural features of lignocellulosic substrates. It has been reported that low cellulose degree of polymerization (DP), crystallinity (CrI), lignin content and high cellulose accessible surface area favor enzymatic hydrolysis [6,7,8,9]. On the other hand, a rapid decrease in the conversion rate was repeated observed as the hydrolysis time extended.…”

Section: Introductionmentioning

confidence: 99%

Physicochemical Structural Changes of Cellulosic Substrates during Enzymatic Saccharification

Ragauskas¹

2016

JABB

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Enzymatic hydrolysis represents one of the major steps and barriers in the commercialization process of converting cellulosic substrates into biofuels and other value added products. It is usually achieved by a synergistic action of enzyme mixture typically consisting of multiple enzymes such as glucanase, cellobiohydrolase and β-glucosidase with different mode of actions. Due to the innate biomass recalcitrance, enzymatic hydrolysis normally starts with an initial fast rate of hydrolysis followed by a rapid decrease of rate toward the end of hydrolysis. With majority of literature studies focusing on the effect of key substrate characteristics on the initial rate or final yield of enzymatic hydrolysis, information about physicochemical structural changes of cellulosic substrates during enzymatic hydrolysis is still quite limited. Consequently, what slows down the reaction rate toward the end of hydrolysis is not well understood. This review highlights recent advances in understanding the structural changes of cellulosic substrates during the hydrolysis process, to better understand the fundamental mechanisms of enzymatic hydrolysis.

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Structural constraints affecting the initial enzymatic hydrolysis of recycled paper

Cited by 66 publications

References 15 publications

Enzymatic Hydrolysis of Pretreated Newspaper Having High Lignin Content for Bioethanol Production

Enzymatic Hydrolysis of Pretreated Newspaper Having High Lignin Content for Bioethanol Production

The Effects of Paper Recycling and its Environmental Impact

Physicochemical Structural Changes of Cellulosic Substrates during Enzymatic Saccharification

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