New evidence for the role of the borohydride pretreatment on the hydrogen peroxide bleaching of kraft pulp

RSC Advances ◽  
2015 ◽  
Vol 5 (119) ◽  
pp. 98067-98074 ◽  
Author(s):  
Jing Li ◽  
Huichao Hu ◽  
Yanting Song ◽  
Xin-Sheng Chai
Keyword(s):  
Hydrogen Peroxide ◽  
Kraft Pulp ◽  
Carbonyl Groups ◽  
Bleaching Process ◽  
Peroxide Bleaching ◽  
Chemical Pulps ◽  
New Evidence ◽  
Lignin Structure

New evidences for the role of borohydride pretreatment in hydrogen peroxide bleaching process of eucalyptus chemical pulps were provided, i.e., suppressing the catalysis effect of Fe(iii), decreasing carbonyl groups, and constituent lignin structure.

The role of copper ions in hydrogen peroxide bleaching: Their origin, removal, and effect on pulp quality

TAPPI Journal ◽  
2012 ◽  
Vol 11 (7) ◽  
pp. 37-46 ◽  
Author(s):  
PEDRO E.G. LOUREIRO ◽  
SANDRINE DUARTE ◽  
DMITRY V. EVTUGUIN ◽  
M. GRAÇA V.S. CARVALHO
Keyword(s):  
Hydrogen Peroxide ◽  
Copper Ions ◽  
Peroxide Bleaching ◽  
Metals Removal ◽  
Peroxide Decomposition ◽  
Equipment Corrosion ◽  
And Performance ◽  
And Control ◽  
Main Effects

This study puts particular emphasis on the role of copper ions in the performance of hydrogen peroxide bleaching (P-stage). Owing to their variable levels across the bleaching line due to washing filtrates, bleaching reagents, and equipment corrosion, these ions can play a major role in hydrogen peroxide decomposition and be detrimental to polysaccharide integrity. In this study, a Cu-contaminated D0(EOP)D1 prebleached pulp was subjected to an acidic washing (A-stage) or chelation (Q-stage) before the alkaline P-stage. The objective was to understand the isolated and combined role of copper ions in peroxide bleaching performance. By applying an experimental design, it was possible to identify the main effects of the pretreatment variables on the extent of metals removal and performance of the P-stage. The acid treatment was unsuccessful in terms of complete copper removal, magnesium preservation, and control of hydrogen peroxide consumption in the following P-stage. Increasing reaction temperature and time of the acidic A-stage improved the brightness stability of the D0(EOP)D1AP bleached pulp. The optimum conditions for chelation pretreatment to maximize the brightness gains obtained in the subsequent P-stage with the lowest peroxide consumption were 0.4% diethylenetriaminepentaacetic acid (DTPA), 80ºC, and 4.5 pH.

scholarly journals Modification of softwood kraft pulp fibres using hydrogen peroxide at acidic conditions

Cellulose ◽  
2020 ◽  
Vol 27 (12) ◽  
pp. 7191-7202
Author(s):  
Axel Martinsson ◽  
Merima Hasani ◽  
Antje Potthast ◽  
Hans Theliander
Keyword(s):  
Hydrogen Peroxide ◽  
Residence Time ◽  
Kraft Pulp ◽  
Hydroxyl Groups ◽  
Carbonyl Groups ◽  
Wet Strength ◽  
Covalent Bonds ◽  
Softwood Kraft Pulp ◽  
Pulp Fibres ◽  
Acidic Conditions

Abstract The aim of this work was to provide softwood kraft pulp fibres with new functionalities by the introduction of carbonyl groups. Carbonyl groups are known to affect properties such as wet strength through the formation of covalent bonds, i.e. hemiacetals. The method developed involves oxidation using hydrogen peroxide at mildly acidic conditions. It was found that the carbonyl group content increased with both increasing temperature and residence time when oxidized at acidic conditions. The number of carboxylic groups, however, remained approximately constant. There was virtually no increase in carbonyl groups when oxidation was performed at alkaline conditions. The maximum increase in carbonyl groups was found at a residence time of 90 min, a reaction temperature of 85 °C and a pH of 4. These conditions resulted in an increase in carbonyl groups from 30 to 122 µmol/g. When formed into a sheet, the pulp oxidized at acidic conditions proved to maintain its structural integrity at aqueous conditions. This indicates the formation of hemiacetal bonds between the introduced carbonyl groups and the hydroxyl groups on the carbohydrate chains. Thus, a possible application for the method could be fibre modification during the final bleaching stage of softwood kraft pulp, where the wet strength of the pulp could be increased.

Study on Magnesium Hydroxide-Based Hydrogen Peroxide Bleaching Process of Nigra poplar CTMP

2011 ◽  
Vol 233-235 ◽  
pp. 1328-1331 ◽  
Author(s):  
Qiang Zhao ◽  
De Zhi Sun ◽  
Ming Yang Zhang ◽  
Su Min Kang
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Time ◽  
Magnesium Hydroxide ◽  
High Yield ◽  
Pulp Yield ◽  
Pulp Bleaching ◽  
Bleaching Process ◽  
Peroxide Bleaching ◽  
Bleaching Condition ◽  
Pulp Consistency

The Mg(OH)2-based peroxide bleaching process of Nigra poplar CTMP pulp was confirmed. The optimal bleaching condition were as follows: 4% H2O2,1% Mg(OH)2, 15% pulp consistency, the reaction temperature was 80°C and the suitable reaction time was 2 hours. The Mg(OH)2-based bleaching process shows significant benefits over sodium hydroxide process. In contrast, magnesium hydroxide bleaching generates higher pulp yield and lower effluent COD at the same chemical dosage. The study shows peroxide bleaching of CTMP pulp with magnesium hydroxide as alkali source is to be an option for the high-yield pulp bleaching.

scholarly journals Oxygen-ozone-hydrogen peroxide bleaching sequence of kraft pulp.

1986 ◽  
Vol 40 (8) ◽  
pp. 743-748
Author(s):  
Toshiro Fujii ◽  
Hiroshi Kamishima ◽  
Isao Akamatsu
Keyword(s):  
Hydrogen Peroxide ◽  
Kraft Pulp ◽  
Peroxide Bleaching

scholarly journals Improvement of Hydrogen Peroxide Bleaching of Kraft Pulp by Acid Pre-treatment

2000 ◽  
Vol 54 (4) ◽  
pp. 556-564,024 ◽  
Author(s):  
Yan Ju ◽  
Hiroshi Ohi ◽  
Yonghao Ni
Keyword(s):  
Hydrogen Peroxide ◽  
Kraft Pulp ◽  
Peroxide Bleaching ◽  
Pre Treatment

scholarly journals Eco-Friendly Bleaching of Soda-AQ Chemical Elephant Dung Pulp

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
Saleem M. ◽  
Yaqoob N. ◽  
Rehman I. Ur-
Keyword(s):  
Hydrogen Peroxide ◽  
Raw Materials ◽  
Basic Requirement ◽  
Sodium Percarbonate ◽  
Cellulosic Fibers ◽  
Peroxide Bleaching ◽  
Paper Making ◽  
Chemical Pulps ◽  
Excellent Source ◽  
Elephant Dung

<div><p><em>Elephant dung is an excellent source of cellulosic fibers that is a basic requirement for paper making. In this study, bleaching was carried out by using eco-friendly bleaching agents such as sodium percarbonate, oxone and hydrogen peroxide. Soda-anthraquinone (soda-AQ) semi-chemical and chemical elephant dung pulps were bleached at varying doses of bleaching agents, bleaching aids and reaction time. Presence of residual lignin after pulping stage was imparting brown color to the pulp and hence was removed by subsequent bleaching stages. Soda-AQ chemical pulps was treated with different multistage bleaching sequences. The results of this study showed that sodium percarbonate and oxone could not achieve targeted brightness for elephant dung pulp samples. Whereas, using three stage hydrogen peroxide bleaching sequence [AP<sub>5</sub>P<sub>3</sub>P<sub>2</sub>] helped to achieve the targeted brightness ~ 60.0 % G.E without much sacrificing the other optical and physical properties of the pulp. Eco-friendly bleaching helped to increase the beauty of the final product. Being rich in fiber, elephant dung pulp has a potential to be blended with other raw materials to make hybrid exotic papers of high market value.<strong></strong></em></p></div>

Hydrogen Peroxide Bleaching to Wine Corks with a Novel Catalyst

2013 ◽  
Vol 734-737 ◽  
pp. 2282-2286 ◽  
Author(s):  
Li Liu ◽  
Shu Ling Cui
Keyword(s):  
Hydrogen Peroxide ◽  
Cork Stopper ◽  
Capillary Effect ◽  
Sewage Disposal ◽  
Bleaching Process ◽  
Peroxide Bleaching ◽  
Novel Catalyst

A novel catalyst CF-R for hydrogen peroxide bleaching to wine cork stopper was chosen to substitute the traditional imported item, and the corresponding bleaching process was studied. The influence of catalyst CF-R dosage, H2O2 concentration, bleaching temperature and time on cork whiteness and capillary effect were discussed. The optimized bleaching process for wine corks was obtained as follows: H2O2 concentration 14%, catalyst CF-R dosage 80g/L, bleaching temperature 70°Cand bleaching time 60 min. Comparing with the expensive imported catalyst, the amount of catalyst CF-R is greatly decreased, as is significant for not only cutting down the expenditure of chemicals, but also minimizing the burden on bleaching sewage disposal.

Oxidized Derivatives of Lipophilic Extractives Formed during Hardwood Kraft Pulp Bleaching

Holzforschung ◽  
2003 ◽  
Vol 57 (5) ◽  
pp. 503-512 ◽  
Author(s):  
C. S. R. Freire ◽  
A. J. D. Silvestre ◽  
C. Pascoal Neto
Keyword(s):  
Hydrogen Peroxide ◽  
Chlorine Dioxide ◽  
Kraft Pulp ◽  
Structural Changes ◽  
Oxidation Products ◽  
Pulp Bleaching ◽  
Peroxide Bleaching ◽  
Kraft Pulp Bleaching ◽  
First Time ◽  
Derivatives Of

Summary The structural changes of E. globulus wood extractives during bleaching with chlorine dioxide (D), oxygen (O), ozone (Z) and hydrogen peroxide (P) were studied. The detailed characterisation of the extractive derivatives detected in the partially bleached D, O, P and Z pulps was achieved by performing reactions of pure reference compounds with the different bleaching agents. The results show that the unsaturated sterols and fatty acids are extensively degraded during chlorine dioxide and ozone bleaching and only partially degraded during oxygen and hydrogen peroxide bleaching. The corresponding saturated extractives as well as the long chain aliphatic alcohols and ω-hydroxyfatty acids were stable during bleaching. The main oxidation products of β-sitosterol and oleic and linoleic acids, including one chlorinated derivative of linoleic acid, were identified here for the first time in E. globulus bleached pulps and bleaching filtrates.

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