Kinetics of Adsorbable Organic Halogen Formation During the First Chlorine Dioxide Bleaching Stage of Eucalyptus Kraft Pulp

Zhu, Huixia; Yao, Shuangquan; Lei, Jiang; Wang, Shuangfei; Qin, Chengrong

doi:10.15376/biores.11.4.8820-8830

Cited by 4 publications

(3 citation statements)

References 21 publications

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“…Song et al constructed the kinetics of laccase-aided chlorine dioxide bleaching and discussed the effects of laccase dosage, hydrogen peroxide dosage, and reaction temperature on the AOX content . Other researchers developed kinetic models of the first or second chlorine dioxide bleaching stage to analyze the factors influencing the reaction rate of AOX. − These studies have shown that AOX emissions can be predicted by the kinetic model of AOX formation, and the AOX emission can be decreased by adjusting the operating conditions based on the kinetic model. Barroca found that the amount of chlorine dioxide presented a nonlinear relationship with the decrease in the light absorption coefficient based on a kinetic model of AOX formation .…”

Section: Introductionmentioning

confidence: 99%

Optimizing Bleaching Operating Conditions Based on Mathematical Programming to Reduce AOX Emissions

Yin

Chen

Ma³

et al. 2022

ACS Omega

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This study describes the optimization of a eucalyptus elemental chlorine-free (ECF) bleach plant to reduce adsorbable organic halogen (AOX). The correlations between operating conditions of each stage and pulp quality indices as well as the AOX content in wastewater are analyzed, taking an ECF bleaching technology (D0EpPD1) as an example. The calculation models of pulp quality indices and AOX content in wastewater are established. Then, an optimization model aiming at minimizing AOX emission is structured. The model shows a good simulation effect because the errors between the calculated and experimental values are within 6.3%. By analyzing the impact of various operating conditions on AOX emissions, it was found that chlorine dioxide reduced in the D0 stage has the greatest impact on AOX. The optimization results show that AOX can be reduced from 90.84 to 79.58 kg/h, a decrease of 12.5%. The verification experiment results based on the optimized operating conditions showed that the experimental results are in good agreement with the calculated results of the optimization model, and the effect of reducing AOX based on the optimization model is obvious.

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Section: Introductionmentioning

confidence: 99%

Optimizing Bleaching Operating Conditions Based on Mathematical Programming to Reduce AOX Emissions

Yin

Chen

Ma³

et al. 2022

ACS Omega

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“…Among these, bleaching is the central step [ 11 ]. Elemental chlorine-free (ECF) bleaching using chlorine dioxide is the primary bleaching method employed in mainstream bleaching technology [ 12 ]. This is because of the excellent selectivity of chlorine dioxide for the delignification of lignin [ 13 , 14 ].…”

Section: Introductionmentioning

confidence: 99%

Effects of the Preferential Oxidation of Phenolic Lignin Using Chlorine Dioxide on Pulp Bleaching Efficiency

Liu

Deng

Liang

et al. 2022

IJMS

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Chlorine dioxide is widely used for pulp bleaching because of its high delignification selectivity. However, efficient and clean chlorine dioxide bleaching is limited by the complexity of the lignin structure. Herein, the oxidation reactions of phenolic (vanillyl alcohol) and non-phenolic (veratryl alcohol) lignin model species were modulated using chlorine dioxide. The effects of chlorine dioxide concentration, reaction temperature, and reaction time on the consumption rate of the model species were also investigated. The optimal consumption rate for the phenolic species was obtained at a chlorine dioxide concentration of 30 mmol·L−1, a reaction temperature of 40 °C, and a reaction time of 10 min, resulting in the consumption of 96.3% of vanillyl alcohol. Its consumption remained essentially unchanged compared with that of traditional chlorine dioxide oxidation. However, the consumption rate of veratryl alcohol was significantly reduced from 78.0% to 17.3%. Additionally, the production of chlorobenzene via the chlorine dioxide oxidation of veratryl alcohol was inhibited. The structural changes in lignin before and after different treatments were analyzed. The overall structure of lignin remained stable during the optimization of the chlorine dioxide oxidation treatment. The signal intensities of several phenolic units were reduced. The effects of the selective oxidation of lignin by chlorine dioxide on the pulp properties were analyzed. Pulp viscosity significantly increased owing to the preferential oxidation of phenolic lignin by chlorine dioxide. The pollution load of bleached effluent was considerably reduced at similar pulp brightness levels. This study provides a new approach to chlorine dioxide bleaching. An efficient and clean bleaching process of the pulp was developed.

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“…Some research about modeling, optimization of pulp bleaching had been done to reduce pollutant generation and bleaching costs in our previous work (Yin et al, 2018;Ma et al, 2020). At present, most of the studied focus on how to reduce AOX emissions theoretically in view of generation mechanism (Zhu et al, 2016(Zhu et al, , 2017Dai et al, 2016), and there are few studies on controlling AOX emissions by mathematical model. People payed more attention to control the bleaching reaction for reducing AOX production (Kaur et al, 2018;Zhang et al, 2018b), without considering reducing the components that may produce AOX from the source.…”

Section: Introductionmentioning

confidence: 99%

Study on Measurement Model of Lignin Content in Pulp After Alkaline Extraction

Chen

Yin

et al. 2021

Journal of Environmental Engineering and Landscape Management

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Because kappa number cannot accurately represent the lignin content in the pulp after alkaline extraction, lead to the excessive dosage of bleaching chemicals added and the pollutant content increases. In order to accurately determine the dosage of bleaching agent, reduce pollutant emissions, a prediction model of lignin content of pulp was established by analyzing the correlation between lignin content and alkaline extraction conditions in this paper. The results show that the established soft sensor model can accurately measure lignin content, it is helpful to determine the amount of bleaching agent more accurately, reduce pollutant generation after pulp bleaching.

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Kinetics of Adsorbable Organic Halogen Formation During the First Chlorine Dioxide Bleaching Stage of Eucalyptus Kraft Pulp

Cited by 4 publications

References 21 publications

Optimizing Bleaching Operating Conditions Based on Mathematical Programming to Reduce AOX Emissions

Optimizing Bleaching Operating Conditions Based on Mathematical Programming to Reduce AOX Emissions

Effects of the Preferential Oxidation of Phenolic Lignin Using Chlorine Dioxide on Pulp Bleaching Efficiency

Study on Measurement Model of Lignin Content in Pulp After Alkaline Extraction

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