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.

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.

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.

Modification in the properties of paper by using cellulase-free xylanase produced from alkalophilic Cellulosimicrobium cellulans CKMX1 in biobleaching of wheat straw pulp

2015 ◽  
Vol 61 (9) ◽  
pp. 671-681 ◽  
Author(s):  
Abhishek Walia ◽  
Preeti Mehta ◽  
Shiwani Guleria ◽  
Chand Karan Shirkot
Keyword(s):  
Wheat Straw ◽  
Paper Industry ◽  
Strength Properties ◽  
Pulp And Paper ◽  
Mushroom Compost ◽  
Bleached Pulp ◽  
Cellulosimicrobium Cellulans ◽  
Wheat Straw Pulp ◽  
Pulp Strength ◽  
Cellulosimicrobium Cellulans Ckmx1

Alkalophilic Cellulosimicrobium cellulans CKMX1 isolated from mushroom compost is an actinomycete that produces industrially important and environmentally safer thermostable cellulase-free xylanase, which is used in the pulp and paper industry as an alternative to the use of toxic chlorinated compounds. Strain CKMX1 was previously characterized by metabolic fingerprinting, whole-cell fatty acids methyl ester analysis, and 16S rDNA and was found to be C. cellulans CKMX1. Crude enzyme (1027.65 U/g DBP) produced by C. cellulans CKMX1, having pH and temperature optima of 8.0 and 60 °C, respectively, in solid state fermentation of apple pomace, was used in the production of bleached wheat straw pulp. Pretreatment with xylanase at a dose of 5 U/g after pulping decreased pulp kappa points by 1.4 as compared with the control. Prebleaching with a xylanase dose of 5 U/g pulp reduced the chlorine charge by 12.5%, increased the final brightness points by approximately 1.42% ISO, and improved the pulp strength properties. Xylanase could be substituted for alkali extraction in C–Ep–D sequence and used for treating chemically bleached pulp, resulting in bleached pulp with higher strength properties. Modification of bleached pulp with 5 U of enzyme/g increased pulp whiteness and breaking length by 1.03% and 60 m, respectively; decreased tear factor of pulp by 7.29%; increased bulk weight by 3.99%, as compared with the original pulp. Reducing sugars and UV-absorbing lignin-derived compound values were considerably higher in xylanase-treated samples. Cellulosimicrobium cellulans CKMX1 has a potential application in the pulp and paper industries.

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.

Improvement in selectivity of ozone bleaching using DTPA as carbohydrate protector for wheat straw pulp

2019 ◽  
Vol 34 (3) ◽  
pp. 271-279 ◽  
Author(s):  
Sandeep Kumar Tripathi ◽  
Nishi Kant Bhardwaj ◽  
Himadri Roy Ghatak
Keyword(s):  
Wheat Straw ◽  
Morphological Properties ◽  
Ozone Treatment ◽  
Physical Strength ◽  
Bleached Pulp ◽  
Pulp Viscosity ◽  
Wheat Straw Pulp ◽  
Mn Content ◽  
And Control ◽  
Ozone Bleaching

Abstract Effect of using diethylenetriamine pentaaceticacid (DTPA) as carbohydrate protector in ozone stage on delignification efficiency, bleaching efficiency, selectivity, metal ions, strength, morphological properties and effluent properties of wheat straw pulp was studied. Using DTPA during ozone treatment viscosity of pulp was improved by 1.1 units, delignification efficiency improved by 13.8 % and pulp brightness improved by 2.5 units compared to that of control. Most importantly the selectivity of ozone treatment was improved by 124 %. Ozone treatment along with DTPA reduced the Fe, Cu and Mn content in the pulp by 52 %, 27 % and 70 %, respectively. Use of DTPA in ozone stage improved the bleached pulp viscosity by 9 %, post colour number by 27 % and reduced the pulp shrinkage by 5 % compared to control pulp. DTPA treated and control pulps have comparable physical strength and morphological properties.

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.

scholarly journals The Use of Mg(OH)2 in the Final Peroxide Bleaching Stage of Wheat Straw Pulp

BioResources ◽  
2013 ◽  
Vol 9 (1) ◽  
Author(s):  
Yan-Lan Liu ◽  
Ke-Fu Chen ◽  
Ben-Ping Lin
Keyword(s):  
Wheat Straw ◽  
Peroxide Bleaching ◽  
Wheat Straw Pulp

Dynamic-head space GC-MS analysis of volatile odorous compounds generated from unbleached and bleached pulps and effects on strength properties during ageing

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Izhar Alam ◽  
Swati Sood ◽  
Chhaya Sharma
Keyword(s):  
Volatile Compounds ◽  
Paper Mill ◽  
Strength Properties ◽  
Degree Of Polymerization ◽  
Ambient Conditions ◽  
Bleached Pulp ◽  
Tensile Index ◽  
Ms Analysis ◽  
Odorous Compounds ◽  
Unbleached Pulp

Abstract Mixed hardwood unbleached (UB) and final bleached (FB) pulp along with the pulp of intermediate bleaching stages from an integrated paper mill have been undertaken for this study. Headspace GC-MS analysis of these pulps was made to identify the odorous compounds which are volatile organic compounds (VOCs), generated during ageing for 60 days. The result showed that a number of pre-generated VOCs such as aliphatic hydrocarbons and aldehydes are observed in the pulp sample which might be came from the process and it has been observed that upon ageing at ambient conditions, some acid functionalized VOC were generated in the pulp. The generation of these VOCs were established by ATR-FTIR analysis and the results showed that intensity of peak absorbance near 3340  cm − 1 {\text{cm}^{-1}} and 1641  cm − 1 {\text{cm}^{-1}} which represents the –OH stretching of acidic functional group and C=O stretch of aldehyde and acidic functional groups increased after ageing. Generation of acid functionalized volatile compounds were observed more in bleached pulp than in unbleached pulp. Degree of polymerization (DP) is pretty much related to the strength of paper. DP of both unbleached and bleached pulp gets reduced upon ageing while more reduction were observed in bleached pulp. Bleached pulps are more prone to degrade as compared to the unbleached pulp in terms of strength properties such as tensile index, breaking length, burst and double fold were observed. 12.3 % and 21.8 % reduction in tensile index was observed for UB and final bleached FB pulp respectively. Burst index of UB and FB pulp were found reduced to 23.8 % and 41.9 % respectively due to ageing. Reduction in the mechanical and optical properties was also observed in intermediate bleaching stages. There is much evidence for the contribution of VOCs to the degradation of paper. The results are strongly suggested that acid functionalized volatile compounds can have strong effects on degradation of cellulosic paper.

Xylanase and laccase aided bio-bleaching of wheat straw pulp

2013 ◽  
Vol 92 (1) ◽  
pp. 131-138 ◽  
Author(s):  
Bhavin S. Dedhia ◽  
Mangesh D. Vetal ◽  
Virendra K. Rathod ◽  
Csoka Levente
Keyword(s):  
Wheat Straw ◽  
Wheat Straw Pulp
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