THE ROLE OF TRANSITION-METAL SPECIES IN DELIGNIFICATION WITH DISTILLED PERACETIC-ACID

Citation
Xz. Zhang et al., THE ROLE OF TRANSITION-METAL SPECIES IN DELIGNIFICATION WITH DISTILLED PERACETIC-ACID, Journal of wood chemistry and technology, 18(3), 1998, pp. 253-266
Citations number
17
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Materials Science, Paper & Wood
ISSN journal
0277-3813
Volume
18
Issue
3
Year of publication
1998
Pages
253 - 266
Database
ISI
SICI code
0277-3813(1998)18:3<253:TROTSI>2.0.ZU;2-H
Abstract
An acid-washed, oxygen-delignified, softwood kraft pulp was delignifie d with peracetic acid (Pa) at initial pH 2.5, 4.8 and 7.0. The inclusi on of 5 ppm on pulp of Mn2+, Fe3+, Cu2+, V5+, or Co2+ caused wasteful decomposition of Pa while Ni2+ had no effect. None of the cations caus ed a significant decrease in kappa number while Co2+ at all pHs and Fe 3+ at pH 2.5 resulted in lower viscosities. In pulp-free solutions, Co 2+ and V5+ catalyzed Pa decomposition much more aggressively than the other cations. The kinetic data supported a previous free-radical mech anism for Co2+ and a similar type mechanism appears to be partially re sponsible for Pa decomposition by vanadium (V).