Selectivity Improvement During Oxygen Delignification by Adsorption of Polymeric Additives, 2002 International Pulp Bleaching Conference Proceedings

Steven Violette and Adriaan van Heiningen

Pulp-strength loss during oxygen delignification is caused by cellulose depolymerization resulting from attack by radicals generated during delignification reactions. The objective of the present research was to investigate the use of radical-scavenging polymeric additives that adsorb on the cellulose surfaces where protection from these radicals is needed. Among the polymers tested were starch, carboxymethylcellulose, galactomannan, xylan, and glucomannan. The highest increases in lignin-cellulose selectivity were observed for guar galactomannan as the adsorbed additive, with significant improvements at charges as low as 0.3% on pulp. At 2.0% guar on pulp, the selectivity improvement was about 30%. The change in cellulose degree of polymerization (DP) is expressed as the number of polymer chain scissions, and the kappa number and cellulose DP changes are corrected for alkali extraction in the absence of oxygen. This method of analysis provides a fundamental understanding of the mechanism of oxygen delignification. Polymer adsorption on pulp was measured by sugar analysis using high performance anionic exchange chromatography (HPAEC). Selectivity measurements were related to the adsorbed amount of polymer additive.

Author: Violette, S., van Heiningen, A.
Selectivity Improvement During Oxygen Delignification by Ads
Selectivity Improvement During Oxygen Delignification by Adsorption of Polymeric Additives, 2002 International Pulp Bleaching Conference Proceedings
32.00

New Releases

TAPPI PRESS Catalog eBook 2024


Experience the Power of Publications in the 2024 TAPPI Press Catalog


Open


 

Kraft Recovery Boilers, Third Edition  


Sponsored by the Recovery Boiler Program R&D Subcommittee of the American Forest & Paper Association (AF&PA) and published by TAPPI Press.


Purchase


 

Handbook For Pulp and Paper Technologists (The SMOOK Book), Fourth Edition

The best-selling text to introduce the entire technology of pulp and paper manufacture.

Purchase

 

Guidelines for Safe Assessment and Operation of Yankee Dryers  


A project of the Yankee Dryer Safety & Reliability Committee.

Purchase

 

Check our newest additions.


TAPPI Press offers some of the most in-depth resources and references for the forest products and related industries. 

See More

   
 

Available for Purchase – Conference Proceedings


TAPPI maintains a record of key conference papers, presentations, and other conference publications, available for purchase in a variety of formats.

See More