authors |
Freire, CSR; Silvestre, AJD; Neto, CP |
nationality |
International |
journal |
JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY |
author keywords |
Eucalyptus kraft pulp; ECF bleaching; lipophilic extractives; sterols; fatty acids; long-chain aliphatic alcohols; beta-sitosterol |
keywords |
CHLORINATED COMPOUNDS; PITCH DEPOSITS; CHEMICAL-COMPOSITION; WOOD EXTRACTIVES; MILL; TCF; GLUCURONOXYLAN; COMPONENTS; AOX |
abstract |
The composition of E. globulus kraft pulp lipophilic extractives and their behaviour during an ECF (DEDED) bleaching sequence were investigated. Sterols; fatty acids, including several alpha- and omega-hydroxyfatty acids; and long-chain aliphatic alcohols are the major lipophilic extractives of the unbleached pulp. During the bleaching, about 80% of the aliphatic extractives are removed from pulp (ca. 70% of the sterols, 70% of the fatty acids, and 90% of the long-chain aliphatic alcohols). The decrease of sterols is mainly due to the degradation of beta-sitosterol by chlorine dioxide, while the decrease of fatty acids and alcohols is essentially assigned to their extraction and elimination with the alkaline filtrates. The major chemical transformations in pulp extractives composition and structure occur in the last bleaching stages. |
publisher |
TAYLOR & FRANCIS INC |
issn |
0277-3813 |
year published |
2005 |
volume |
25 |
issue |
1-2 |
beginning page |
67 |
ending page |
80 |
digital object identifier (doi) |
10.1081/WCT-200058241 |
web of science category |
Materials Science, Paper & Wood |
subject category |
Materials Science |
unique article identifier |
WOS:000229998600006
|