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

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.

Download Full-text

Oxidized Derivatives of Lipophilic Extractives Formed during Hardwood Kraft Pulp Bleaching

Holzforschung ◽

10.1515/hf.2003.075 ◽

2003 ◽

Vol 57 (5) ◽

pp. 503-512 ◽

Cited By ~ 11

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.

Download Full-text

Hydrogen peroxide bleaching of hardwood kraft pulp with adsorbed birch xylan and its effect on paper properties

BioResources ◽

10.15376/biores.6.1.721-736 ◽

2011 ◽

Vol 6 (1) ◽

pp. 721-736

Author(s):

Lizi Li ◽

Sanghoon Lee ◽

Hak Lae Lee ◽

Hye Jung Youn

Keyword(s):

Hydrogen Peroxide ◽

Optical Properties ◽

Kraft Pulp ◽

Strength Properties ◽

Pulp Fibers ◽

Paper Properties ◽

Peroxide Bleaching ◽

Initial Ph ◽

The Relationship ◽

Temperature Time

The adsorption of xylan on pulp fibers improves the strength properties of paper. However, the optical properties are decreased significantly. The objective of our research was to bleach hardwood kraft pulp with adsorbed birch xylan by hydrogen peroxide and study the effect of bleaching parameters on paper properties. The bleaching parameters studied included bleaching temperature, time, initial pH as well as MgSO4 dosage. The optical properties (whiteness, brightness, opacity) and physical properties (tensile index, tearing index, bulk) of handsheets made from the pulp bleached with different process variables were measured. The results showed that better optical properties were obtained with higher bleaching temperature, longer bleaching time, and more MgSO4 dosage. Bleaching from an initial pH of 11 provided the highest brightness value. On the other hand, strength properties were improved with decreasing of the bleaching temperature, and increasing the initial pH and MgSO4 dosage. The relationship between strength properties and bleaching time varied depending on bleaching temperature. According to the results, both good mechanical properties and optical properties could be achieved when the operating parameters were controlled properly. Therefore hydrogen peroxide bleaching was proved to be a suitable method for bleaching hardwood kraft pulp with adsorption of birch xylan.

Download Full-text

Application of a Catalyst in Peroxide Bleaching of Eucalyptus Kraft Pulp

Holzforschung ◽

10.1515/hf.2000.068 ◽

2000 ◽

Vol 54 (4) ◽

pp. 407-412 ◽

Cited By ~ 8

Author(s):

L. Kühne ◽

J. Odermatt ◽

T. Wachter

Keyword(s):

Hydrogen Peroxide ◽

Kraft Pulp ◽

Pulp Bleaching ◽

Selective Catalyst ◽

Peroxide Bleaching ◽

Softwood Pulp ◽

Kraft Pulp Bleaching ◽

Eucalyptus Kraft Pulp ◽

Softwood Kraft Pulp

Summary A binuclear [Mn(III)Mn(IV)(μ-O)2(μ-CH3COO)L](ClO4−)2 complex with L = 1,2 Bis-(4,7-dimethyl-1,4,7-triazacyclonon-1-yl)-ethane, described as a selective catalyst in hydrogen peroxide bleaching of softwood pulps, was tested in hardwood kraft pulp bleaching. The catalyst application gave rise to a higher consumption of peroxide which resulted in higher pulp brightness. The delignification improvement caused by the catalyst was shown to be much lower compared to catalysed peroxide bleaching of softwood kraft pulp. In contrast to the results of softwood pulp bleaching no selectivity improvements could be found when using the catalyst in bleaching of eucalyptus kraft pulp.

Download Full-text

Effect of ultrasonic pre-treatment of thermomechanical pulp on hydrogen peroxide bleaching

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/42/1/012018 ◽

2012 ◽

Vol 42 ◽

pp. 012018

Author(s):

E Loranger ◽

A Charles ◽

C Daneault

Keyword(s):

Hydrogen Peroxide ◽

Thermomechanical Pulp ◽

Peroxide Bleaching ◽

Pre Treatment

Download Full-text

Kraft pulp bleaching with a P-stage catalyzed by both bicarbonate and TAED

TAPPI Journal ◽

10.32964/tj18.7.409 ◽

2019 ◽

Vol 18 (7) ◽

pp. 409-414

Author(s):

N. DAS ◽

S.K. BOSE ◽

R.C. FRANCIS

Keyword(s):

Hydrogen Peroxide ◽

Sodium Bicarbonate ◽

Sodium Hydroxide ◽

Sodium Carbonate ◽

Kraft Pulp ◽

Kraft Pulps ◽

Pulp Bleaching ◽

Peroxide Bleaching ◽

Kraft Pulp Bleaching ◽

Peroxide Activation

Peroxide bleaching of softwood and hardwood (eucalypt) kraft pulps was performed in solutions of sodium bicarbonate (NaHCO3), sodium carbonate (Na2CO3), and sodium hydroxide (NaOH). The conventional P stage (hydrogen peroxide + sodium hydroxide; H2O2 + NaOH) was the most effective brightening system without an additional activator. However, peroxide activation by bicarbonate anion (HCO3–) was obvious in all cases where NaHCO3 or Na2CO3 was used. When N,N,N’,N’-tetraacetylethylenediamine (TAED) was added to the bleaching system, Na2CO3 as the alkali source afforded equal or slightly higher bleached brightness compared to NaOH usage for both the softwood and hardwood pulps. This outcome is attributed to simultaneous peroxide activation by HCO3 and TAED. When applied to the eucalypt pulp, the H2O2/Na2CO3/TAED bleaching system also decreased the brightness loss due to thermal reversion.

Download Full-text

DMD Pretreated H2O2 Bleaching Technologyof Massion Pine Dissolving Pulp

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.332-334.399 ◽

2011 ◽

Vol 332-334 ◽

pp. 399-402

Author(s):

Min Du ◽

Xin Ping Li ◽

Cai Xia Ma

Keyword(s):

Hydrogen Peroxide ◽

Dissolving Pulp ◽

Bleaching Process ◽

Peroxide Bleaching ◽

Optimum Parameters ◽

Pre Treatment ◽

Time Of Reaction

Dimethyldioxirane (DMD) pre-treatment of Massion Pine dissolving pulp has been studied in order to improve the effect of hydrogen peroxide bleaching. The influence of the dosage of acetone and peroxymonosulfate (PMS), the ratio of acetone to PMS, temperature and time of reaction were studied. The optimum parameters of DMD pre-bleaching process were at the 0.7% dosage of acetone and PMS while the ratio of the two was 3:4, and pretreated at 60°C for 100 minute. Pretreated with DMD at this condition, the brightness of final pulp increased 11.14% and the content of α-cellulose increased 9.62% compared with the pulp which bleached by hydrogen peroxide without DMD pretreatment.

Download Full-text

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

TAPPI Journal ◽

10.32964/tj11.7.37 ◽

2012 ◽

Vol 11 (7) ◽

pp. 37-46 ◽

Cited By ~ 1

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.

Download Full-text

Selected Kefir Water from Malaysia Attenuates Hydrogen Peroxide-Induced Oxidative Stress by Upregulating Endogenous Antioxidant Levels in SH-SY5Y Neuroblastoma Cells

Antioxidants ◽

10.3390/antiox10060940 ◽

2021 ◽

Vol 10 (6) ◽

pp. 940

Author(s):

Muganti Rajah Kumar ◽

Swee Keong Yeap ◽

Han Chung Lee ◽

Nurul Elyani Mohamad ◽

Muhammad Nazirul Mubin Aziz ◽

...

Keyword(s):

Oxidative Stress ◽

Hydrogen Peroxide ◽

Neuroblastoma Cells ◽

Annexin V ◽

Morphological Features ◽

Lower Percentage ◽

Total Phenolic ◽

Neuroprotective Effects ◽

Antioxidant Power ◽

Pre Treatment

Kefir, a fermented probiotic drink was tested for its potential anti-oxidative, anti-apoptotic, and neuroprotective effects to attenuate cellular oxidative stress on human SH-SY5Y neuroblastoma cells. Here, the antioxidant potentials of the six different kefir water samples were analysed by total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant power (FRAP), and 2,2′-diphenyl-1-picrylhydrazyl radical (DPPH) assays, whereas the anti-apoptotic activity on hydrogen peroxide (H2O2) induced SH-SY5Y cells was examined using MTT, AO/PI double staining, and PI/Annexin V-FITC assays. The surface and internal morphological features of SH-SY5Y cells were studied using scanning and transmission electron microscopy. The results indicate that Kefir B showed the higher TPC (1.96 ± 0.54 µg GAE/µL), TFC (1.09 ± 0.02 µg CAT eq/µL), FRAP (19.68 ± 0.11 mM FRAP eq/50 µL), and DPPH (0.45 ± 0.06 mg/mL) activities compared to the other kefir samples. The MTT and PI/Annexin V-FITC assays showed that Kefir B pre-treatment at 10 mg/mL for 48 h resulted in greater cytoprotection (97.04%), and a significantly lower percentage of necrotic cells (7.79%), respectively. The Kefir B pre-treatment also resulted in greater protection to cytoplasmic and cytoskeleton inclusion, along with the conservation of the surface morphological features and the overall integrity of SH-SY5Y cells. Our findings indicate that the anti-oxidative, anti-apoptosis, and neuroprotective effects of kefir were mediated via the upregulation of SOD and catalase, as well as the modulation of apoptotic genes (Tp73, Bax, and Bcl-2).

Download Full-text