scholarly journals Optimization of Full ECF Bleaching Sequences Using Novel Models

10.5772/7665 ◽  
2010 ◽  
Author(s):  
Sandeep Jain ◽  
Gerard Morth
Keyword(s):  
Ecf Bleaching

Application of pure, thermostable, alkali-tolerant xylanase in bleaching of oxygen-delignified pine kraft pulp

TAPPI Journal ◽  
2015 ◽  
Vol 14 (11) ◽  
pp. 689-694
Author(s):  
QINGZHI MA ◽  
QI WANG ◽  
CHU WANG ◽  
NIANJIE FENG ◽  
HUAMIN ZHAI
Keyword(s):  
Intrinsic Viscosity ◽  
Chlorine Dioxide ◽  
High Purity ◽  
Kraft Pulp ◽  
Alkaline Media ◽  
Industrial Scale ◽  
Elemental Chlorine ◽  
Effect Of Oxygen ◽  
Alkaline Tolerant ◽  
Ecf Bleaching

The effect of oxygen (O2)-delignified pine kraft pulp pretreatment by high-purity, thermostable, and alkaline-tolerant xylanases on elemental chlorine free (ECF) bleaching of O2-delignification kraft pulp was studied. The study found that xylanase pretreatment preserved the intrinsic viscosity and yield of O2-delignified pulp while causing about 7% of delignification with high delignification selectivity. The xylanases with high purity, higher thermostability (75°C~80°C) in highly alkaline media (pH 8.0~9.5) could be applied on an industrial scale. Pulp pretreatment by the high-purity, thermostable, and alkaline tolerant xylanases could improve pulp brightness or reduce the chlorine dioxide (ClO2) consumption. In a D0ED1D2 bleaching sequence using the same amount of ClO2, the xylanase-pretreated pulp obtained a higher brightness (88.2% vs. 89.7% ISO) at the enzyme dose of 2 U/g pulp; or for the same brightness as control (88.2% ISO), the ClO2 dosage in the D0 stage was reduced by 27%, which represents a 16% savings in total ClO2 used for bleaching.

scholarly journals Enzyme and Alkali-Aided ECF Bleaching of Kraft Bamboo Pulp

BioResources ◽  
2015 ◽  
Vol 10 (4) ◽  
Author(s):  
Yingying Du ◽  
Chengrong Qin ◽  
Xiannan Huang ◽  
Shaungxi Nie ◽  
Xueping Song
Keyword(s):  
Bamboo Pulp ◽  
Ecf Bleaching

Initiating ECF bleaching sequences of eucalyptus kraft pulps with Z/D and Z/E stages

Holzforschung ◽  
2010 ◽  
Vol 64 (1) ◽  
Author(s):  
Juan C. García ◽  
Francisco López ◽  
Antonio Pérez ◽  
M. Angels Pèlach ◽  
Pere Mutjé ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Chlorine Dioxide ◽  
Ecological Impact ◽  
Substantial Reduction ◽  
Reference Sequence ◽  
Kraft Pulps ◽  
Eucalyptus Kraft Pulp ◽  
The Impact ◽  
Ecf Bleaching ◽  
Ozone Bleaching

Abstract Ozone bleaching is a common practice in pulping, and also of eucalyptus, where it is usually applied in combination with bleaching sequences based on oxygen, hydrogen peroxide, or chlorine dioxide. Ozone has been proven to be a highly efficient and competitive bleaching chemical in terms of delignification efficiency, low costs, and reducing ecological impact. The objective of the present work was to evaluate technology with ozone/alkaline extraction (Z/E) and ozone/chlorine dioxide (Z/D) for bleaching of eucalyptus kraft pulp. Primarily, the impact of these bleaching steps on refinability and quality of pulp should be investigated. As reference, the sequence D*(EP)D (hot chlorine dioxide, extraction in presence of hydrogen peroxide, chlorine dioxide) was selected, which is considered as the state-of-the-art bleaching in elemental chlorine free (ECF) bleaching technology. Various bleaching sequences with ozone in their first step (Z/D(EP)DP, Z/D(EP)DD, Z/EDP, Z/EDD and A*Z/EDP) were found to provide kraft pulps of similar brightness and in similar yield as the reference sequence D*(EP)D. The kappa number, viscosity, and the contents of glucose and xylose, and hexenuronic acid of the pulps were also similar. In addition, the Z sequences resulted in a substantial reduction of the total chlorine dioxide consumption (more than 30.3% in all cases). The A*Z/EDP sequence, which proved to be the most efficient, yielded 87.5% ClO2 reduction. The studied bleaching sequences also resulted in substantially improved brightness reversal with regard to the reference sequence. The sequence A*Z/EDP was also the most efficient as regards the removal or organochlorines (OX) from the pulp and their reduction in the effluents (AOX). Ozone bleaching sequences improved paper strength, especially with the A*Z/EDP sequence.

Behavior of Eucalyptus Kraft Pulp Extractives Components across ECF Bleaching and Their Impact on Brightness Reversion

2011 ◽  
Vol 31 (2) ◽  
pp. 103-120 ◽  
Author(s):  
Célia R. A. Maltha ◽  
Luiz C. A. Barbosa ◽  
Marco A. B. Azevedo ◽  
Jorge L. Colodette
Keyword(s):  
Kraft Pulp ◽  
Brightness Reversion ◽  
Eucalyptus Kraft Pulp ◽  
Ecf Bleaching

Effect of incorporation of ozone prior to ECF bleaching on pulp, paper and effluent quality

2019 ◽  
Vol 236 ◽  
pp. 134-145 ◽  
Author(s):  
Daljeet Kaur ◽  
Nishi K. Bhardwaj ◽  
Rajesh Kumar Lohchab
Keyword(s):  
Effluent Quality ◽  
Pulp Paper ◽  
Ecf Bleaching

Lipophilic Extractives inEucalyptus globulusKraft Pulps. Behavior during ECF Bleaching

2005 ◽  
Vol 25 (1-2) ◽  
pp. 67-80 ◽  
Author(s):  
C. S. R. Freire ◽  
A. J. D. Silvestre ◽  
C. Pascoal Neto
Keyword(s):  
Ecf Bleaching

scholarly journals Lipophilic Extractives from Eucalyptus globulus Pulp during Kraft Cooking Followed by TCF and ECF Bleaching

Holzforschung ◽  
2001 ◽  
Vol 55 (3) ◽  
pp. 260-264 ◽  
Author(s):  
A. Gutiérrez ◽  
J. Romero ◽  
J.C. del Río
Keyword(s):  
Gas Chromatography ◽  
Chlorine Dioxide ◽  
Eucalyptus Globulus ◽  
Gas Chromatography Mass Spectrometry ◽  
Chemical Analyses ◽  
Wood Extractives ◽  
Elemental Chlorine ◽  
Kraft Cooking ◽  
Ecf Bleaching ◽  
Paper Pulps

SummaryThe chemical composition of lipophilic extractives in paper pulps fromEucalyptus globuluswood during kraft cooking followed by TCF (“totally chlorine free”) and ECF (“elemental chlorine free”) bleaching sequences has been determined by gas chromatography and gas chromatography-mass spectrometry. The chemical analyses revealed that the composition of the lipophilic extractives in pulp after kraft cooking and TCF bleaching with hydrogen peroxide was similar to that ofE. globuluswood extractives, sitosterol and sitosterol esters being the predominant compounds. In contrast, the presence of these compounds was almost negligible in pulp after ECF bleaching with chlorine dioxide and only the saturated sterol stigmastanol, in both free and esterified forms, survived the bleaching.

Bleach boosting effect of xylanase A from Bacillus halodurans C-125 in ECF bleaching of wheat straw pulp

2013 ◽  
Vol 52 (2) ◽  
pp. 91-98 ◽  
Author(s):  
Xiao-qiong Lin ◽  
Shuang-yan Han ◽  
Na Zhang ◽  
Hui Hu ◽  
Sui-ping Zheng ◽  
...  
Keyword(s):  
Wheat Straw ◽  
Bacillus Halodurans ◽  
Wheat Straw Pulp ◽  
Ecf Bleaching
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