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Oxalate formation during hydrogen peroxide-reinforced oxygen delignification
Journal of Industrial and Engineering Chemistry, 2018Abstract The effects of different process parameters (alkali dosage, hydrogen peroxide dosage, temperature, reaction time, and oxygen pressure) on oxalate formation during hydrogen peroxide-reinforced oxygen delignification (OP) of Eucalyptus kraft pulp were investigated in the present study.
Yingying Liu +4 more
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Oxygen delignification kinetics: CSTR and batch reactor comparison
AIChE Journal, 2007AbstractIn the past, oxygen delignification studies were mostly performed in batch reactors, whereby the caustic and dissolved oxygen concentrations are changing during the reaction. Also the lignin content and cellulose degradation of the pulp are only established at the end of an experiment when the sample is removed from the reactor.
Yun Ji +2 more
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On the role of carbohydrates in oxygen delignification
Nordic Pulp & Paper Research Journal, 2005The long-term trend regarding wood is an increase in price. Because wood contributes to a large part of production costs, the efficient utilisation of wood is greatly desired to reduce production costs for kraft pulp producers. During the 1990s, the development of improved modified kraft cooking began, which led to higher yields. There was also a trend
Helena Wedin +2 more
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Lignocellulosic fiber charge enhancement by catalytic oxidation during oxygen delignification
Journal of Colloid and Interface Science, 2007A series of one-stage oxygen delignification treatments with a softwood (SW) kraft pulp were studied employing 0.0-0.5% of a bismuth ruthenium pyrochlore oxide catalyst. The results demonstrated that a 0.09-0.18% charge of catalyst in an oxygen stage provided a 52.2-116.0% increase of carboxylic acid groups in the cellulosic component of kraft pulps ...
Dongcheng, Zhang +3 more
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Holzforschung, 2011
AbstractOxidation of softwood and hardwood kraft lignins was observed under conditions of oxygen delignification (90°C and 110°C; 0.6 and 0.9 MPa) as a function of time by means of a number of analysis techniques and quantitative information was obtained on the degradation and formation of various compounds and structures.
Kuitunen, S. +7 more
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AbstractOxidation of softwood and hardwood kraft lignins was observed under conditions of oxygen delignification (90°C and 110°C; 0.6 and 0.9 MPa) as a function of time by means of a number of analysis techniques and quantitative information was obtained on the degradation and formation of various compounds and structures.
Kuitunen, S. +7 more
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Pulp delignification with oxygen and copper(II)-polyimine complexes
Holzforschung, 2013Abstract Ten Cu(II)-polyimine complexes were tested as potential catalysts in oxygen delignification of softwood kraft pulps. The ligands were chosen from the terpyridine and the phenanthroline families, including several neocuproines. One diamine-phenanthrene (daphen) was also investigated.
Gueneau, Basile +3 more
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Modelling oxygen delignification in pulp processing operations
2005A mathematical model of oxygen delignification for pulp processing operations has been developed to predict the kappa number (lignin content) and pulp strength (CED viscosity) as a function of system operation variables. The model incorporates a set of appropriate chemical reaction kinetics chosen from those available in the literature and gas ...
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Xylan deposition onto eucalypt pulp fibers during oxygen delignification
Holzforschung, 2011Abstract A novel alternative was investigated for elevating the xylan content of eucalyptus pulp through xylan deposition in the course of the oxygen delignification stage. The pH in the range of 10–13 was the only variable evaluated, while the other variables were kept constant in a range similar to industrial practice.
Muguet, M.C.S. +3 more
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Oxygen Delignification Chemistry and Its Impact on Pulp Fibers
Journal of Wood Chemistry and Technology, 2003Abstract Two southern pine kraft pulps with kappa numbers of 30.0 (SW1-0) and 48.0 (SW2-0) were oxygen delignified by 30–60% by varying the reaction temperature (78–110°C) and charge of sodium hydroxide (1.6–4.4%). O-bleachability was found to be correlated to the incoming kappa number and charge of sodium hydroxide employed. In general, a lower charge
Rallming Yang +3 more
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Mass transfer and kinetics in oxygen delignification
2020ABSTRACT MASS TRANSFER AND KINETICS IN OXYGEN DELIGNIFICATION Doğan, Ismail Ph.D., Department of Chemical Engineering Supervisor : Prof. Dr. Hayrettin Yücel Co-Supervisor : Prof. Dr. Güniz Gürüz November 2004, 147 pages In this study, the kinetic analysis of oxygen delignification of Turkish southern hardwood Kraft pulp was carried out.
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