The wood extractives in alkaline peroxide bleaching of groundwood from Norway spruce

Ekman, Rainer; Holmblom, B.

doi:10.3183/npprj-1989-04-03-p188-191

Cited by 24 publications

(19 citation statements)

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“…Degradation of some colloidal substances during alkaline peroxide bleaching probably caused the decrease of particle size. 8,26 3.3. Determination of Lignin.…”

Section: Resultsmentioning

confidence: 98%

Influence of Alkaline Treatment and Alkaline Peroxide Bleaching of Aspen Chemithermomechanical Pulp on Dissolved and Colloidal Substances

Miao

Zhong

Qin

et al. 2014

Ind. Eng. Chem. Res.

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Dissolved and colloidal substances (DCS) will be released during mechanical pulping and following bleaching operations. The accumulation of DCS in paper machine systems can bring various negative impacts on papermaking operations. In present study, the influence of alkaline treatment and alkaline peroxide bleaching of aspen chemithermomechanical pulp on released DCS was evaluated based on general DCS properties, lignin content, and carbohydrate and organic extractives compositions. Results showed that both treatments could promote the DCS release by increasing the concentration and cationic demand of DCS samples. However, alkaline peroxide bleaching caused the decrease in turbidity and average particle size. The total amounts of dissolved lignin, carbohydrates, and organic extractives were also increased. The dissolved lignin-related substances and carbohydrates were the predominant components of DCS. In the extractives, alkaline peroxide bleaching mainly resulted in the release of some lignin-degraded substances and a slight degradation of unsaturated fatty acids and their esters.

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“…Degradation of some colloidal substances during alkaline peroxide bleaching probably caused the decrease of particle size. 8,26 3.3. Determination of Lignin.…”

Section: Resultsmentioning

confidence: 98%

Influence of Alkaline Treatment and Alkaline Peroxide Bleaching of Aspen Chemithermomechanical Pulp on Dissolved and Colloidal Substances

Miao

Zhong

Qin

et al. 2014

Ind. Eng. Chem. Res.

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“…[9] During peroxide bleaching of mechanical pulps the amount of lignans in TMP water is substantially decreased. [11,16] On the other hand, peroxide bleaching results in higher overall loss of fiber material, probably also due to lignin material leaching. [6,11] Recently it was shown that aromatic substances are released from spruce TMP fibers into water in considerable amounts (up to 10 mg/g TMP at alkaline conditions, with and without hydrogen peroxide).…”

Section: Introductionmentioning

confidence: 99%

Dissolved Lignin and Other Aromatic Substances in Thermomechanical Pulp Waters

Pranovich

Reunanen

Sjöholm

et al. 2005

Journal of Wood Chemistry and Technology

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Dissolved aromatic substances in water suspensions of unbleached and peroxide-bleached spruce thermomechanical pulp (TMP) were isolated by sorption on XAD-8 resin and fractionated into lignin and oligomeric aromatic substances (OAS). The fractions were characterized by chromatographic (GC and HP-SEC) and spectrometric (FT-IR, 13 C-NMR, GC-MS) methods, as well as by GC after direct on-line pyrolysis and thermally assisted hydrolysis and methylation. The dissolved lignin in unbleached TMP water was structurally similar to spruce milled-wood lignin (MWL), but its average molar-mass was lower and the mass distribution more narrow. The oligomeric aromatic substances included phenolic dimers, trimers, and tetramers that were structurally different from those of MWL. After peroxide bleaching the amount of dissolved semipolar (MTBE) extractives and oligomeric aromatic substances was We thank M.Sc Nina Å kerback for the FT-IR analyses of lignin samples. Thanks are due to Kenneth Sundberg for valuable comments on the manuscript.109 much lower. The amount of dissolved lignin from wood fibers was, on the contrary, much higher. The lignin released from TMP after bleaching was extensively oxidized and had a slightly higher average molar-mass than lignin released from unbleached TMP.

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“…The lignans are easily oxidized and degraded during PB as well, and in the lignin structure, carboxylic groups are formed via cleavage of aromatic rings. The amount of lipophilic extractives is not changed significantly by PB, but an oxidation of conjugated double bonds in ReA occurs (Ekman and Holmbom 1989a).…”

Section: Introductionmentioning

confidence: 99%

Selective purification of bleached spruce TMP process water by induced air flotation (IAF)

et al. 2013

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The environmentally benign closure of water systems in paper mills leads to the problem of accumulation of dissolved and colloidal wood substances (DCS) in process water. Notably, pitch affects the pulp and paper production negatively and increases the demand for additional treatment of the process water. In the present article, the purification of thermomechanical pulping process water from the alkaline peroxide bleaching stage has been investigated, with the induced air flotation (IAF) in focus. The following parameters were considered concerning the IAF efficiency to remove detrimental substances: concentration of cationic foaming agent, pH value, calcium concentration, and temperature. The amounts and characteristics of residual DCS were determined by gas chromatography and turbidity measurements. Residual concentrations of the foaming agent dodecyltrimetylammonium chloride were determined by electrospray ionization mass spectrometry. Up to 90% of pitch was removed, whereas hemicelluloses, which are important in preventing pitch problems, remained in the waters. Up to 70% of the pectic acids accounted for the high cationic demand of the process waters were removed by optimization of the IAF parameters. The presented separation process gives new opportunities to a selective purification of the process waters.

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The wood extractives in alkaline peroxide bleaching of groundwood from Norway spruce

Cited by 24 publications

References 0 publications

Influence of Alkaline Treatment and Alkaline Peroxide Bleaching of Aspen Chemithermomechanical Pulp on Dissolved and Colloidal Substances

Influence of Alkaline Treatment and Alkaline Peroxide Bleaching of Aspen Chemithermomechanical Pulp on Dissolved and Colloidal Substances

Dissolved Lignin and Other Aromatic Substances in Thermomechanical Pulp Waters

Selective purification of bleached spruce TMP process water by induced air flotation (IAF)

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