Effect of Hydrogen Peroxide and Anthraquinone on the Selectivity and Hexenuronic Acid Content of Mixed Tropical Hardwood Kraft Pulp during Oxygen Delignification

Chong, Yin Hui; Daud, Wan Rosli Wan; Leh, Cheu Peng

doi:10.15376/biores.8.2.2547-2557

Cited by 2 publications

(2 citation statements)

References 7 publications

(7 reference statements)

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“…Thus, it can be seen that the selectivity curves of the two bleaching stages showed the same trend whereby the Op-stage method was improved by shifting towards the left (lower kappa number). Based on our previous results (Chong et al 2013a), the maximum bleaching selectivity of the Op-stage (0.71) was higher than that of the O-stage (0.53). These selectivity curves are used as reference lines for the following research to observe the effect of pre-treatment on tropical mixed hardwood kraft pulp after an ordinary or improved O-stage.…”

Section: Selectivity Of Oxygen Delignification With and Without Additmentioning

confidence: 66%

Application of Photo, Peracetic Acid, and Combination Pre-treatments in Improving Totally Chlorine-Free Bleaching Selectivity

Chong¹,

Daud²,

Poh³

et al. 2015

BioResources

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The application of totally chlorine-free bleaching (TCF) is well recognised for its environmental compatibility. However, its application is restricted in comparison to a chlorine-based bleaching sequence. TCF bleaching produces pulp with relatively lower brightness and strength properties. Oxygen delignification (O-stage) is commonly used as a first bleaching stage; therefore its selectivity influences TCF bleaching performance. In this study, the selectivity of the O-stage and hydrogen peroxidereinforced O-stage (Op-stage) on tropical hardwood kraft pulp were 0.53 and 0.71, with 37.8% and 55.5% kappa number (Kn) reductions, respectively. The addition of photo pre-treatment prior to the O-stage and Op-stage improved the Kn reduction to 53.7% and 59.2%; consequently the selectivity was enhanced to 1.0 and 0.73, respectively. The Fourier transform infrared spectra showed that photo pre-treatments improved the selectivity by protecting the cellulose from carbonyl-induced degradation. This protective effect was more prominent in the O-stage than the Op-stage. However, the combination of peracetic acid and photo treatment did not further increase bleaching selectivity in either stage. In short, blue light and UV irradiation treatment with or without the prior addition of peracetic acid to ordinary or hydrogen peroxidereinforced oxygen delignified pulp displayed a similar bleaching effect on the resultant pulp.

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Section: Selectivity Of Oxygen Delignification With and Without Additmentioning

confidence: 66%

Application of Photo, Peracetic Acid, and Combination Pre-treatments in Improving Totally Chlorine-Free Bleaching Selectivity

Chong¹,

Daud²,

Poh³

et al. 2015

BioResources

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“…The selectivity of the medium consistency oxygen delignification stage improved by offering a greater effect on KaNo reduction, but induced more serious cellulose degradation (Chong et al, 2013). Reaction selectivity is commonly calculated as the ratio of the change in KaNo to the change in pulp viscosity during medium consistency oxygen delignification.…”

Section: Table 1 Typical Conditions In Industrial Medium Consistency Oxygen Delignificationmentioning

confidence: 99%

Improving Reaction Selectivity with NaOH Charges and Reaction Time in the Medium Consistency Oxygen Delignification Process

Irawan

Darmawan

Roesyadi

et al. 2020

IJTech

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As more delignification is targeted, fiber degradation becomes a main issue in the pulping process. Sodium hydroxide (NaOH) is highly related to pulp quality in the medium consistency oxygen delignification process. Accordingly, the purpose of this research was to study the effect of NaOH charges and reaction time on reaction selectivity during the pulping process through medium consistency oxygen delignification. This research used Eucalyptus pelita and Acacia mangium pulp with a kappa number (KaNo) of 17-18. The medium consistency oxygen delignification process condition included a temperature of 80°C and oxygen pressure of 1 bar, while the reaction times were 20, 40, 60, 80, and 100 min. The NaOH charges were 5, 10, 15, 20, and 25 kg/t of pulp. The analysis parameters used were KaNo and viscosity. The variation in reaction time did not show a significant change in KaNo. The increase in reaction time and NaOH charge variations, meanwhile, can reduce pulp viscosity. Higher NaOH values significantly increased the delignification degree, and the higher NaOH charges and reaction times together lowered the degree of polymerization (DP). The variation in reaction time indicated that with a longer reaction time, the lower the DP, and with a higher NaOH charge and longer reaction time, the lower the reaction selectivity.

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Effect of Hydrogen Peroxide and Anthraquinone on the Selectivity and Hexenuronic Acid Content of Mixed Tropical Hardwood Kraft Pulp during Oxygen Delignification

Cited by 2 publications

References 7 publications

Application of Photo, Peracetic Acid, and Combination Pre-treatments in Improving Totally Chlorine-Free Bleaching Selectivity

Application of Photo, Peracetic Acid, and Combination Pre-treatments in Improving Totally Chlorine-Free Bleaching Selectivity

Improving Reaction Selectivity with NaOH Charges and Reaction Time in the Medium Consistency Oxygen Delignification Process

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