Improvement of high-yield pulp properties by using a small amount of bleached wheat straw pulp

Abstract High-yield pulp (HYP) has found wide applications in many paper grades. Usually, the strength properties of HYP must be improved and its freeness fine-tuned before sending it for paper machining, by means of refining at a low consistency, which requires energy. In this study, the possibility of avoiding refining of HYP was investigated by adding low percentages of refined and bleached wheat straw pulp (BWSP) to a HYP-containing mixture. The results show that the strength properties of a HYP and a hardwood kraft (HWKP) mixture can be improved with approximately 10% refined BWSP. In this manner, refining energy of 20 kWh t-1 is needed, and the pulp quality is improved to a similar level to that obtained from the same pulp mixture refined with an energy input of 70 kWh t-1. This approach also works for 100% HYP. The practical implication is that only a small percentage of refined BWSP is needed to improve the strength property of a HYP or HYP/HWKP mixtures, so that less refining energy is required in the low-consistency refining process.

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Study on Xylanase-Aided Bleaching of Wheat Straw KP

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.726-731.548 ◽

2013 ◽

Vol 726-731 ◽

pp. 548-551

Author(s):

Li Jun Zhao ◽

Mei Hong Niu ◽

Jian Zhang ◽

Yan Ning Sun ◽

Na Li

Keyword(s):

Hydrogen Peroxide ◽

Wheat Straw ◽

Oxygen Pressure ◽

Treatment Time ◽

Optimal Concentration ◽

Experimental Results ◽

Peroxide Bleaching ◽

Wheat Straw Pulp ◽

Pulp Properties ◽

Oxygen Bleaching

Before oxygen bleaching and hydrogen peroxide bleaching, wheat straw pulp was bleached using xylanase. The effect of enzymatic stage on pulp properties and bleachability has been studied and compared with reference (control) pulps, processed without enzyme addition. Experimental results showed that, the optimal concentration of wheat straw pulp was 10%, the optimal treatment time and dose of enzyme was 60 min and 1.25AXU/g respectively. Oxygen pressure decreased from 0.6MPa to 0.5MPa when conditions of hydrogen peroxide bleachingremained unchanged and wheat straw pulp achieved the same whiteness. Hydrogen peroxide consumption decreased from 2% to 1.8% when oxygen bleaching has the same conditions and achieved the same white degree.

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Effect of introducing ozone in elemental chlorine free bleaching of pulp on generation of chlorophenolic compounds

Nordic Pulp & Paper Research Journal ◽

10.1515/npprj-2020-0062 ◽

2020 ◽

Vol 35 (4) ◽

pp. 559-568

Author(s):

Sandeep Kumar Tripathi ◽

Nishi Kant Bhardwaj ◽

Himadri Roy Ghatak

Keyword(s):

Optical Properties ◽

Wheat Straw ◽

Oxygen Demand ◽

Elemental Chlorine ◽

Wheat Straw Pulp ◽

Pulp Properties ◽

Organic Halogens ◽

Ecf Bleaching ◽

Adsorbable Organic Halogens

AbstractEffect of using ozone before elemental chlorine free (ECF) bleaching of oxygen delignified wheat straw pulp produced following soda-anthraquinone pulping on bleaching effluent and pulp properties was studied. The effluent generated during bleaching of pulp contains high amount of adsorbable organic halogens (AOX), chemical oxygen demand (COD), biochemical oxygen demand (BOD) and highly toxic chlorophenolic compounds. This study is aimed to utilise green chemistry approach during bleaching of one of the abundantly used agro residue wheat straw for improving the quality of bleaching effluent and pulp properties. Introducing ozone stage before ECF bleaching resulted in significant reduction of chloriphenolic compounds like chlorocatechols by 48.9 %, chloroguaiacols by 33.3 %, chlorovanillins by 28.4 % and chlorophenols by 26.7 % in the effluent compared to those of control. Incorporation of ozone before ECF bleaching BOD, COD, AOX and colour were reduced by 40.0 %, 41.1 %, 46.7 % and 57.8 %, respectively, as compared to control. Optical properties like brightness and whiteness of the pulp bleached using ozone were also improved by 2.5 units and 4.0 units, respectively as compared to that with control.

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Using of Magnesium Hydroxide and Sodium Hydroxide in DP Beaching of NaOH-AQ Wheat Straw Pulp

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.690-693.1455 ◽

2013 ◽

Vol 690-693 ◽

pp. 1455-1460

Author(s):

Wen Bo Wang ◽

Fan Gong Kong ◽

Shou Juan Wang ◽

Ya Jie Zhong ◽

Gui Hua Yang

Keyword(s):

Tensile Strength ◽

Sodium Hydroxide ◽

Wheat Straw ◽

Magnesium Hydroxide ◽

Chlorine Dioxide ◽

Control Agent ◽

Bleaching Process ◽

Peroxide Bleaching ◽

Wheat Straw Pulp ◽

Pulp Properties

Sodium hydroxide (NaOH) substituted by magnesium hydroxide (Mg(OH)2) as control agent and alkali source were investigated in chlorine dioxide bleaching and hydrogen peroxide bleaching of NaOH-AQ wheat straw pulp. The effects of alkali sources on pulp properties, including brightness and tensile strength, were investigated. The four experimental groups, including DNaOHPNaOH, DNaOHPMg(OH)2, D Mg(OH)2PNaOH and DMg(OH)2PMg(OH)2, were studied in this paper. The results showed that the brightness and tensile strength of DMg(OH)2PMg(OH)2 pulp was slightly lower than that of DNaOHPNaOH pulp. But there were more residual ClO2 and residual H2O2 in the effluents of DMg(OH)2PMg(OH)2 bleaching process than that in the effluents of DNaOHPNaOH bleaching process, which illustrated that DMg(OH)2PMg(OH)2 bleaching process had higher bleaching efficiency than DNaOHPNaOH bleaching process. The influence of Mg(OH)2 replacing NaOH was more obvious when it was used in the bleaching process of P stage than that in the D stage. The replacement of NaOH with Mg(OH)2 in D Stage can lower the dosage of alkali used in the following P stage.

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The Effect of Microwave Treatment on the Hydrogen Peroxide Bleaching of Soda-AQ Wheat Straw Pulp

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.236-238.1307 ◽

2011 ◽

Vol 236-238 ◽

pp. 1307-1312

Author(s):

Chao Jun Wu ◽

Chuan Shan Zhao ◽

Jun Li ◽

Ke FU Chen

Keyword(s):

Hydrogen Peroxide ◽

Wheat Straw ◽

Fiber Length ◽

Weighted Average ◽

Microwave Treatment ◽

Arithmetic Average ◽

Peroxide Bleaching ◽

Bleached Pulp ◽

Infra Red ◽

Wheat Straw Pulp

In this paper, the effect of microwave treatment on the hydrogen peroxide bleaching of Soda-AQ wheat-straw pulp was investigated. The results showed that microwave treatment could increase the brightness of the hydrogen peroxide bleached pulp. The fiber coarseness of microwave enhancing peroxide bleached pulp was higher than that of the peroxide bleached pulp. However, the arithmetic average fiber length, the length weighted average fiber length and weight weighted average fiber length of the former was lower than that of the latter. Fourier transform infra-red spectroscopy (FTIR) and X-ray diffraction (XRD) spectra showed that CrI(%) crystallinity of microwave enhancing peroxide bleached pulp was similar as that of the peroxide bleached pulp but all higher than that of the Soda-AQ wheat-straw pulp. N·O′KI infra-red crystalline index of microwave enhancing peroxide bleached pulp were lower than that of the peroxide bleached pulp. The FTIR spectra of lignin showed that the microwave treatment had some influences on the methoxyl and phenolic group in lignin.

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Production of Cellulosic Ethanol from Enzymatically Hydrolysed Wheat Straws

Applied Sciences ◽

10.3390/app10217638 ◽

2020 ◽

Vol 10 (21) ◽

pp. 7638

Author(s):

Vasile-Florin Ursachi ◽

Gheorghe Gutt

Keyword(s):

Enzymatic Hydrolysis ◽

Wheat Straw ◽

Cellulosic Ethanol ◽

Raw Material ◽

High Yield ◽

Liquid Ratio ◽

Hydrolysis Process ◽

Pretreatment Conditions ◽

Pretreated Wheat Straw ◽

First Time

The aim of this study is to find the optimal pretreatment conditions and hydrolysis in order to obtain a high yield of bioethanol from wheat straw. The pretreatments were performed with different concentrations of sulphuric acid 1, 2 and 3% (v/v), and were followed by an enzymatic hydrolysis that was performed by varying the solid-to-liquid ratio (1/20, 1/25 and 1/30 g/mL) and the enzyme dose (30/30 µL/g, 60/60 µL/g and 90/90 µL/g Viscozyme® L/Celluclast® 1.5 L). This mix of enzymes was used for the first time in the hydrolysis process of wheat straws which was previously pretreated with dilute sulfuric acid. Scanning electron microscopy indicated significant differences in the structural composition of the samples because of the pretreatment with H2SO4 at different concentrations, and ATR-FTIR analysis highlighted the changes in the chemical composition in the pretreated wheat straw as compared to the untreated one. HPLC-RID was used to identify and quantify the carbohydrates content resulted from enzymatic hydrolysis to evaluate the potential of using wheat straws as a raw material for production of cellulosic ethanol in Romania. The highest degradation of lignocellulosic material was obtained in the case of pretreatment with 3% H2SO4 (v/v), a solid-to-liquid ratio of 1/30 and an enzyme dose of 90/90 µL/g. Simultaneous saccharification and fermentation were performed using Saccharomyces cerevisiae yeast, and for monitoring the fermentation process a BlueSens equipment was used provided with ethanol, O2 and CO2 cap sensors mounted on the fermentation flasks. The highest concentration of bioethanol was obtained after 48 h of fermentation and it reached 1.20% (v/v).

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Xylanase and laccase aided bio-bleaching of wheat straw pulp

The Canadian Journal of Chemical Engineering ◽

10.1002/cjce.21798 ◽

2013 ◽

Vol 92 (1) ◽

pp. 131-138 ◽

Cited By ~ 11

Author(s):

Bhavin S. Dedhia ◽

Mangesh D. Vetal ◽

Virendra K. Rathod ◽

Csoka Levente

Keyword(s):

Wheat Straw ◽

Wheat Straw Pulp

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Study of Selecting Proper Chitosan from Various Chitosan Sample as Paper Strengthening Agent

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.117-119.1421 ◽

2011 ◽

Vol 117-119 ◽

pp. 1421-1424

Author(s):

Yong Sheng Ma ◽

Xian Hui Sun

Keyword(s):

Wheat Straw ◽

Strengthening Effect ◽

Chitosan Sample ◽

Viscosity Range ◽

Wheat Straw Pulp

It is usually reported that chitosan is used as paper strengthening agent. However, it is sorry that the study choosing chitosan which DD (degree of de-acetyl )and viscosity is filtered by experiments is blank. Many chitosan samples of wide viscosity range and wide DD range were tested by their strengthening effect on bleched wheat straw pulp. Then a few sample of chitosan is selected because of their obvious strengthening effect on pulp. This study could be as the foundation of further research of chitosan used as paper strengthening agent.

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