Totally Chlorine Free Bleaching of Eucalyptus globulus Dissolving Pulps Delignified with Peroxyformic Acid and Formic Acid

Holzforschung ◽  
2002 ◽  
Vol 56 (1) ◽  
pp. 60-66 ◽  
Author(s):  
S. Abad ◽  
B. Saake ◽  
J. Puls ◽  
J. C. Parajó
Keyword(s):  
Hydrogen Peroxide ◽  
Formic Acid ◽  
Eucalyptus Globulus ◽  
Molar Mass ◽  
Oxygen Delignification ◽  
Operational Conditions ◽  
Bleached Pulp ◽  
Target Values ◽  
Dissolving Pulps ◽  
Peroxyformic Acid

Summary Eucalyptus globulus wood samples were delignified in two-stage treatments carried out in media made up of formic acid, water and hydrogen peroxide under selected operational conditions. The pulps were subjected to Totally Chlorine Free (TCF) bleaching sequences. Alkaline treatments, oxygen delignification, ozone stages and treatments with peroxyacids were assayed in order to reach the target values for dissolving pulps. Under the best conditions, a fully bleached pulp (91.6% ISO brightness) with SCAN viscosity of 649 ml/g and favourable molar mass distribution was obtained.

Kinetics of Formation of Peroxyformic Acid

1996 ◽  
Vol 61 (10) ◽  
pp. 1457-1463 ◽  
Author(s):  
Vladimír Mošovský ◽  
Zuzana Cvengrošová ◽  
Alexander Kaszonyi ◽  
Milan Králik ◽  
Milan Hronec
Keyword(s):  
Hydrogen Peroxide ◽  
Kinetic Model ◽  
Formic Acid ◽  
Oxidation Kinetics ◽  
Oxidation Process ◽  
Aqueous Hydrogen Peroxide ◽  
Kinetics Of Formation ◽  
Peroxyformic Acid ◽  
Kinetics Of

Oxidation kinetics of formic acid with aqueous hydrogen peroxide (30-70%) has been studied at 45 °C with 0-0.1 M H2SO4 as a catalyst. A kinetic model has been suggested which satisfactorily describes the oxidation process of formic acid to peroxyformic acid.

Comparative Studies of Hemicelluloses Solubilized during the Treatments of Maize Stems with Peroxymonosulfuric Acid, Peroxyformic Acid, Peracetic Acid, and Hydrogen Peroxide. Part 2. Spectroscopic and Thermal Characterizations

Holzforschung ◽  
2000 ◽  
Vol 54 (5) ◽  
pp. 492-496 ◽  
Author(s):  
Runcang Sun ◽  
J. Tomkinson ◽  
Z. C. Geng ◽  
N. J. Wang
Keyword(s):  
Hydrogen Peroxide ◽  
Peracetic Acid ◽  
Molar Mass ◽  
Gel Permeation Chromatography ◽  
Spectroscopic Techniques ◽  
Average Molar Mass ◽  
Alkaline Peroxide ◽  
Peroxyformic Acid ◽  
Thermal Stability Of ◽  
Obvious Feature

Summary Ten hemicellulosic preparations, obtained by treatments of the water-extracted maize stems with peroxymonosulfuric acid, peroxyformic acid, peracetic acid, and 2% hydrogen peroxide under the conditions given, respectively, were investigated by gel permeation chromatography and spectroscopic techniques such as Fourier transform infrared and carbon-13 nuclear magnetic resonance. Under an optimum extracting condition (2% H2O2, 45°C, 12 h, pH 11.5–12.0), the hemicelluloses obtained represented 63.3–64.7 % of the original hemicelluloses and had high weight-average molar mass between 69060 and 54740 g mol−1. The most obvious feature was found that the alkaline peroxide treatment of the stems under the conditions used did not affect the overall structure of the hemicelluloses. The thermal stability of the hemicelluloses was found to increase slightly with increasing molar mass. All the hemicellulosic preparations were, however, to varying degree thermally unstable at temperature above 180°C.

The Effect of Microwave Treatment on the Hydrogen Peroxide Bleaching of Soda-AQ Wheat Straw Pulp

2011 ◽  
Vol 236-238 ◽  
pp. 1307-1312
Author(s):  
Chao Jun Wu ◽  
Chuan Shan Zhao ◽  
Jun Li ◽  
Ke FU Chen
Keyword(s):  
Hydrogen Peroxide ◽  
Wheat Straw ◽  
Fiber Length ◽  
Weighted Average ◽  
Microwave Treatment ◽  
Arithmetic Average ◽  
Peroxide Bleaching ◽  
Bleached Pulp ◽  
Infra Red ◽  
Wheat Straw Pulp

In this paper, the effect of microwave treatment on the hydrogen peroxide bleaching of Soda-AQ wheat-straw pulp was investigated. The results showed that microwave treatment could increase the brightness of the hydrogen peroxide bleached pulp. The fiber coarseness of microwave enhancing peroxide bleached pulp was higher than that of the peroxide bleached pulp. However, the arithmetic average fiber length, the length weighted average fiber length and weight weighted average fiber length of the former was lower than that of the latter. Fourier transform infra-red spectroscopy (FTIR) and X-ray diffraction (XRD) spectra showed that CrI(%) crystallinity of microwave enhancing peroxide bleached pulp was similar as that of the peroxide bleached pulp but all higher than that of the Soda-AQ wheat-straw pulp. N·O′KI infra-red crystalline index of microwave enhancing peroxide bleached pulp were lower than that of the peroxide bleached pulp. The FTIR spectra of lignin showed that the microwave treatment had some influences on the methoxyl and phenolic group in lignin.

The effect of hydrogen peroxide concentration and solid loading on the fractionation of biomass in formic acid

2014 ◽  
Vol 111 ◽  
pp. 374-384 ◽  
Author(s):  
K. Dussan ◽  
B. Girisuta ◽  
D. Haverty ◽  
J.J. Leahy ◽  
M.H.B. Hayes
Keyword(s):  
Hydrogen Peroxide ◽  
Formic Acid ◽  
Solid Loading

scholarly journals Deposition of xylan isolated from Pennisetum purpureum on fibres of Eucalyptus globulus and characterisation of the composition of the surface xylans by immunolabelling and enzymatic peeling

Holzforschung ◽  
2018 ◽  
Vol 72 (11) ◽  
pp. 915-922 ◽  
Author(s):  
Tarja Tamminen ◽  
Atte Mikkelson ◽  
Matti Siika-aho ◽  
Kristiina Kruus ◽  
Jaakko Pere ◽  
...  
Keyword(s):  
Eucalyptus Globulus ◽  
Potential Method ◽  
Pennisetum Purpureum ◽  
Composition Gradient ◽  
Elephant Grass ◽  
Oxygen Delignification ◽  
High Quality ◽  
Enzymatic Peeling ◽  
Cold Caustic Extraction ◽  
Hydrolysis Of

AbstractAdsorption of xylan on pulp is a potential method to improve its properties, especially refinability for high quality printing and writing (P&W) paper grades. In this study, elephant grass [Pennisetum purpureum(Schumach.)] xylan was used for this purpose. The xylan was extracted using cold caustic extraction (CCE) fromP. purpureumbrown pulp, produced by the Soda-AQ process (kappa 20). Xylan resorption was accomplished during the oxygen delignification phase of eucalypt [Eucalyptus globulus(Labill.)] pulp to avoid problems induced by the colour of the lignin-contaminated deposited xylan. Immunolabelling and enzymatic peeling methodologies were compared for the analysis of the spatial distribution of xylan in the fibre wall. The labelling appeared unevenly as faint and brighter patches on fibre surfaces. Increased labelling of xylan was detected on the samples with precipitatedP. purpureumxylan. The enzymatic peeling method using a total hydrolysis enzyme mixture yielded a composition gradient as a function of time, showing clear xylose (Xyl) enrichment in the very beginning of the reaction, reflecting hydrolysis of fibre surfaces. Pure xylanase and endoglucanase hydrolyses yielded different product patterns and kinetics compared to total hydrolysis, but interpretation of those results in terms of xylan localisation was not straightforward.

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