Investigations into Laccase-Mediator Delignification of Kraft Pulps

Holzforschung ◽  
1999 ◽  
Vol 53 (5) ◽  
pp. 498-502 ◽  
Author(s):  
J. Sealey ◽  
A.J. Ragauskas ◽  
T.J. Elder
Keyword(s):  
Bond Dissociation Energy ◽  
Dissociation Energy ◽  
Kraft Pulp ◽  
Substituent Effects ◽  
Computational Results ◽  
Kraft Pulps ◽  
Bond Dissociation ◽  
Structure Activity ◽  
Softwood Kraft Pulp

SummaryThe structure activity effects of 1-hydroxy benzotriazole and phthalimide derivatives as mediators for laccase were studied. Using a softwood kraft pulp it was shown that the N-hydroxy unit is a key component of 1-hydroxybenzotriazole for efficient laccase mediator delignification to occur. It was also found that the 1-hydroxybenzotriazole structure was very sensitive to substituent effects with respect to laccase-mediator delignification. Computational results from PM3 indicate that the bond dissociation energy, and electronic factors of the radical may contribute to the efficiency of the mediator for LMS delignification.

Substituent Effects on the C−H Bond Dissociation Energy of Toluene. A Density Functional Study

1996 ◽  
Vol 61 (2) ◽  
pp. 746-750 ◽  
Author(s):  
Yun-Dong Wu ◽  
Chui-Ling Wong ◽  
Kyle W. K. Chan ◽  
Guo-Zhen Ji ◽  
Xi-Kui Jiang
Keyword(s):  
Bond Dissociation Energy ◽  
Dissociation Energy ◽  
Density Functional ◽  
Substituent Effects ◽  
Functional Study ◽  
Density Functional Study ◽  
Bond Dissociation

Optimization of elemental chlorine-free bleaching for a softwood kraft pulp • part 2: economic analysis of chemical and steam consumption

TAPPI Journal ◽  
2010 ◽  
Vol 9 (9) ◽  
pp. 47-53 ◽  
Author(s):  
BRIAN N. BROGDON
Keyword(s):  
Chlorine Dioxide ◽  
Previous Investigation ◽  
Kraft Pulp ◽  
Energy Costs ◽  
Alkaline Extraction ◽  
Stage Versus ◽  
Kraft Pulps ◽  
Steam Consumption ◽  
Elemental Chlorine ◽  
Softwood Kraft Pulp

Our previous investigation [1] re-analyzed the data from Basta and co-workers (1992 TAPPI Pulping Conference) to demonstrate how oxidative alkaline extraction can be augmented and how these changes affect chlorine dioxide consumption with elemental chlorine-free (ECF) sequences. The current study manipulates extraction delignification variables to curtail bleaching costs with a conventional U.S. Southern softwood kraft pulp. The economic advantages of ~0.35% to 0.65% H2O2 peroxide reinforcement in a 70°C (EOP)-stage versus 90°C (EO)-stage are predisposed to the brightness targets, to short or long bleach sequences, and to mill energy costs. Minimized bleaching costs are generally realized when a 90°C (EO) is employed in D0(EO)D1 bleaching, whereas a 70°C (EOP) is economically advantageous for D0(EOP)D1E2D2 bleaching. The findings we disclose here help to clarify previous ECF optimization studies of conventional softwood kraft pulps.

Sign in / Sign up

Export Citation Format

Share Document