Recent developments in the stabilization of hydrogen peroxide bleaching of pulps: An overview

Wuorimaa, Anna; Jokela, Reija; Aksela, Reijo

doi:10.3183/npprj-2006-21-04-p435-443

Cited by 44 publications

(32 citation statements)

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“…and Ca 2? (Burton 1986;Lapierre et al 1995;Wuorimaa et al 2006). Manganese can effectively be removed from pulps by using chelating agents such as EDTA and DTPA (Granholm et al 2009;Granholm et al 2010a, b;Lapierre et al 1995).…”

Section: Introductionmentioning

confidence: 95%

Sorption of metal ions to untreated, alkali-treated and peroxide-bleached TMP

Granholm

Pranovich

et al. 2010

Cellulose

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Knowledge about how different metal ions are bound to pulp fibers is very important for optimal metal management in pulping processes. A column chromatographic method was used to assess the differences in affinity of 14 metal ions to untreated, alkali-treated and peroxide-bleached thermomechanical pulp (TMP). A method of competition between cations in the column chromatographic experiments was used in the sorption experiments, with an excess of each metal ion compared to the total capacity of the pulp studied. The method is very sensitive and even small differences in affinities can be detected. By combining the results from sorption experiments with four different metal ion mixtures the following order of affinity was obtained: types of pulps showed the same affinity order. Lead and copper ions were clearly most strongly bound to the pulp fibers. Within the alkali and alkaline earth metal groups the differences in affinity were quite small. The sorption of metal ions to pulp fibers takes place mainly by complexation, where the divalent metal ions are coordinated to functional groups (acid groups) in the fiber phase. Protonation constants and concentrations of acid groups were determined by potentiometric titration. A model with two carboxyl groups and two phenolic hydroxyl groups satisfied best the experimental data. By treatment with alkali and peroxide new acid groups were created and the total binding capacity of hydrogen ions increased from 137 leq/g for untreated pulp to 187 and 228 leq/g for alkali-treated and peroxide-treated pulp, respectively.

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Section: Introductionmentioning

confidence: 95%

Sorption of metal ions to untreated, alkali-treated and peroxide-bleached TMP

Granholm

Pranovich

et al. 2010

Cellulose

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“…MgSO 4 is commonly added during peroxide bleaching as a stabilizer, since Mg deactivates the harmful effect of Fe, Cu and Mn, in the presence of the pulp (Wuorimaa et al 2006). For this study, we preferred not to add any extra Mg to perceive if different results would be obtained, depending on the Mg complexed and removed from the pulp.…”

Section: Bleaching Sequencementioning

confidence: 99%

“…However, the presence of transition metals, such as iron (Fe), manganese (Mn) and copper (Cu), affects the efficiency of the oxidizing agent because they catalyze the degradation of hydrogen peroxide. These metals are in the process as impurities of chemicals used in the bleaching, washing waters and wood itself and the control of its presence is very important to minimize hydrogen peroxide degradation and maximize bleaching efficiency (Wuorimaa et al 2006). On the other hand, the presence of magnesium (Mg) in the bleaching step is important to stabilize the metal ions that increase peroxide degradation (Colodette et al 1989;Abbot and Brown 1990).…”

Section: Introductionmentioning

confidence: 99%

Pre-treatment of the paper pulp in the bleaching process using biodegradable chelating agents

Pinto¹,

Ascenso

Barros

et al. 2013

Int. J. Environ. Sci. Technol.

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The aim of this work was to study the application of two biodegradable chelating agents, pyridine-2,6-dicarboxylic acid (PDA) and methylglycinediacetic acid (MGDA), in the treatment of the pulp, prior to hydrogen peroxide bleaching. Such compounds must remove transition metals (Mn, Fe and Cu) from pulp, that catalyze the degradation of hydrogen peroxide, and Ca, which is also problematic due to the formation of precipitates that accumulate in the equipment. Computer simulations were first performed to study the best conditions for metal complexation, and optimum pH was defined as 5-5.5 for PDA and 6.5-7 for MGDA. Metals removal from the pulp, as well as the subsequent bleaching process (Q-P1-Paa-P2), were tested experimentally, and performances were compared to ethylenediaminetetracetic acid (EDTA). PDA removed both Mn and Ca efficiently, leaving most Mg in the pulp after first chelation stage, while MGDA had a lower Ca removal, even using a higher pH and concentration. Residual hydrogen peroxide and kappa number after peroxide stages showed a similar bleaching efficiency between the studied compounds and EDTA.

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“…2). Hydroxyl-acrylate in peroxide bleaching has been reported to be an effective stabilizer in peroxide bleaching (Yonghao 2005;Wurorimaa et al 2006). Poly-hydroxyl acrylic acid is an effective stabilizer due to its metal binding ability and possibly due to its radical scavenging ability.…”

Section: Resultsmentioning

confidence: 99%

“…Polyvinylpyrrolidone maleic acid-styrene or propenes, co-polymers of butadiene-maleic acid, and grafted polymers are examples of polymeric stabilizers that have been reported in the literature. Hydroxyacrylate in peroxide bleaching has been reported to be an effective stabilizer for peroxide bleaching (Ni 2005;Wurorimaa et al 2006). The results show that silicate and PHAS have the highest peroxide stabilizing efficiency in terms of brightness and residual peroxide (Hamalainen et al 2007).…”

Section: Deinking Of Different Furnishes Of Recycled Mow Onp and Ommentioning

confidence: 99%

Deinking of Different Furnishes of Recycled MOW, ONP, and OMG Pulps in Silicate-Free Conditions Using Organic Complex of PHASS

2012

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Sodium silicate causes problems in papermaking such as deposit formation, decreased retention, and lower sheet strength. Due to these problems, chemical deinking of different recycled papers furnishes including 100% ONP, 80% ONP, and 20% OMG, and a combination of 70% ONP/ 20% OMG/ 10% MOW was accomplished using an organic complexing agent which included poly-hydroxyl acrylic acid and sodium salt (PHAAS) in silicate-free conditions. PHAAS was utilized at four levels of 0.3, 0.5, 0.7, and 1% (based on oven-dry weight of recycled paper) rather than sodium silicate. The optical and physical properties of deinked pulp were compared to control pulp (conventional deinking containing 2% sodium silicate). The results showed that the paper brightness was improved and the yellowness, dirt count, and dirt area were decreased significantly by increasing PHAAS charge up to 0.9%. Also, in different recycled paper furnishes above mentioned, using different charges of PHAAS had different effects on paper opacity. Using different charges of PHAAS (especially 0.7 to 0.9%) decreased paper caliper, increased paper air resistance, increased freeness, and gave similar or slightly better paper tear indices. Differences of tear indices were not significant at confidence level of 99%. Based on the present research, the use of 0.7 to 0.9% PHAAS in place of sodium silicate is advisable because of the better quality of final papers compared to conventional deinking process.

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Recent developments in the stabilization of hydrogen peroxide bleaching of pulps: An overview

Cited by 44 publications

References 0 publications

Sorption of metal ions to untreated, alkali-treated and peroxide-bleached TMP

Sorption of metal ions to untreated, alkali-treated and peroxide-bleached TMP

Pre-treatment of the paper pulp in the bleaching process using biodegradable chelating agents

Deinking of Different Furnishes of Recycled MOW, ONP, and OMG Pulps in Silicate-Free Conditions Using Organic Complex of PHASS

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