Study on Xylanase-Aided Bleaching of Wheat Straw KP

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.

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

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.

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

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.

Improvement of bleached wheat straw pulp properties by using aspen high-yield pulp

2012 ◽  
Vol 120 ◽  
pp. 40-44 ◽  
Author(s):  
Hongjie Zhang ◽  
Jianguo Li ◽  
Huiren Hu ◽  
Zhibin He ◽  
Yonghao Ni
Keyword(s):  
Wheat Straw ◽  
High Yield ◽  
Wheat Straw Pulp ◽  
Pulp Properties

Improvement of Wheat-Straw Pulp Properties with an Alkali-Tolerant Xylanase fromPseudomonassp. G6-2

1996 ◽  
pp. 308-316 ◽  
Author(s):  
Jiachuan Chen ◽  
Jianyun Yang ◽  
Yinbo Qu ◽  
Peiji Gao ◽  
Baomin Wang ◽  
...  
Keyword(s):  
Wheat Straw ◽  
Wheat Straw Pulp ◽  
Pulp Properties

The Role of Ferulic Acid Removal during Bleaching of Wheat Straw Mechanical Pulp with Peroxygen Reagents

Holzforschung ◽  
2003 ◽  
Vol 57 (3) ◽  
pp. 282-288 ◽  
Author(s):  
G. X. Pan ◽  
C. I. Thomson ◽  
G. J. Leary
Keyword(s):  
Ferulic Acid ◽  
Wheat Straw ◽  
Model Compounds ◽  
Mechanical Pulp ◽  
Peroxide Bleaching ◽  
Wheat Straw Pulp

Summary The present paper reports our investigation into the use of two peroxygen reagents, peroxymonosulfate (PMS) and dimethyldioxirane (DMD), in bleaching sequences with peroxide to bleach wheat straw mechanical pulp, their reactivity with ferulic acid model compounds, and the likely relation between the two aspects. It was observed that combinations of PMS or DMD with peroxide offered a synergy leading to substantially improved brightness development in bleaching of wheat straw pulp. At the same time, these oxidizing reagents, especially DMD, were shown to be highly reactive with ferulic acid derivatives and increased the removal of ferulic acid from wheat straw pulp in bleaching. The results would suggest that the presence of non-lignin, peroxide-resistant chromophoric components, such as ferulic acid derivatives, might be an important factor limiting the brightness development of wheat straw mechanical pulp by conventional peroxide bleaching.

Mg(OH)2 as Alkaline Source in Peroxide Bleaching of Wheat Straw Pulp

2011 ◽  
Vol 233-235 ◽  
pp. 813-816
Author(s):  
Ben Ping Lin ◽  
Yan Lan Liu ◽  
Ke Fu Chen
Keyword(s):  
Wheat Straw ◽  
Partial Substitution ◽  
Peroxide Bleaching ◽  
Positive Effects ◽  
Bleached Pulp ◽  
Wheat Straw Pulp ◽  
Unbleached Pulp

The present work sought to make a contribution to the study on application of Mg(OH)2 in peroxide bleaching of the wheat straw soda-AQ pulp. The results showed that: (1) for an unbleached pulp, when 24-73% of the NaOH was replaced with Mg(OH)2, a higher brightness and viscosity were achieved comparing to the NaOH as the sole alkaline source. The brightness and viscosity of the bleached pulp at 48% of Mg(OH)2 replacement were respectively 6.4%ISO and 107 mL.g-1 higher than those of the NaOH as the sole alkaline source. (2) for a chelated oxygen-delignified pulp, the brightness of bleached pulp at 24% Mg(OH)2 replacement was considerable to that of the NaOH as the sole alkaline source, and at 48% Mg(OH)2replacement 2.8% ISOlowerthan that of the NaOH as the sole alkaline source. While the viscosity increased consistently with the increase of Mg(OH)2, and the COD load of bleaching filtrates at 24-48% Mg(OH)2 replacement was lower 22-31% than that of the NaOH as the sole alkaline source. Therefore, partial substitution of Mg(OH)2 for NaOH had positive effects on peroxide bleaching of wheat straw soda-AQ pulp.

Research on the Bleaching Process of the Non-Silicon Oxygen Bleaching Stabilizer

2014 ◽  
Vol 685 ◽  
pp. 64-67
Author(s):  
Hua Ling He ◽  
Sheng Lu ◽  
Ming Su Song ◽  
Zhi Cai Yu ◽  
De Hong Cheng
Keyword(s):  
Hydrogen Peroxide ◽  
Breaking Strength ◽  
Tetraacetic Acid ◽  
Optimal Conditions ◽  
Hydrogen Peroxide Decomposition ◽  
Bleaching Process ◽  
Peroxide Bleaching ◽  
Peroxide Decomposition ◽  
Silicon Oxygen ◽  
Oxygen Bleaching

In this study, a type of non-silicon oxygen bleaching stabilizer was used to cotton fabric in the hydrogen peroxide bleaching process. This type of novel non-silicon oxygen bleaching stabilizer was prepared mainly with ethylene diamine tetraacetic acid (EDTA) and magnesium chloride. The results showed that adding the non-silicon oxygen bleaching stabilizer into the bleaching solution obviously decreased the hydrogen peroxide decomposition rate and improved the fabric whiteness. Optimal conditions was found as follow: non-silicon oxygen bleaching stabilizer 4.5 g/l; bleaching temperature 75-85 °C; pH of bleaching liquid 11; bleaching time 40-45 min. In summary, the results showed that the self-made non-silicon oxygen bleaching stabilizer could make the cotton fabrics obtained great whiteness, capillary ability and breaking strength.

Application Study of Cationic Polymethyl Acrylate Emulsion as Papermaking Sizing Agent

2012 ◽  
Vol 479-481 ◽  
pp. 504-507 ◽  
Author(s):  
Yong Sheng Ma ◽  
Yun Fa Chen ◽  
Xian Hui Sun ◽  
Chuan Jun Zhao ◽  
Shou Jie Nie
Keyword(s):  
Wheat Straw ◽  
Emulsion Polymerization ◽  
Wood Pulp ◽  
Experimental Results ◽  
Application Study ◽  
Petroleum Resin ◽  
Wheat Straw Pulp ◽  
Acrylate Emulsion

The cationic polymethyl acrylate (CPMA) emulsion which was prepared with no soap emulsion polymerization was used with petroleum resin sizing agent in bleached wheat straw pulp and wood pulp as papermaking sizing agent. It was showed that by the experimental results that when the dosage of composite sizing agent composed of CPMA emulsion and anionic petroleum resin sizing agent was 0.2% absolute dry pulp, sizing degree and white degree of handsheet made of bleached wheat straw pulp were improved 33% and 5.2%ISO respectively. It was also showed that when the dosage of composite sizing agent was 0.2% absolute dry pulp, sizing degree and white degree of handsheet made of wood pulp were improved 37% and 4.2%ISO respectively.

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

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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