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Low environmental impact bleaching sequences for attaining high brightness level with eucalyptus SPP pulp

The alternatives used for minimizing the usage of chlorine dioxide in bleaching sequences included a hot acid hydrolysis (Ahot) stage, the use of hot chlorine dioxide (Dhot) and ozone stages at medium consistency and high consistency (Zmc and Zhc), in addition to stages with atmospheric hydrogen peroxide (P) and pressurized hydrogen peroxide (PO). The results were interpreted based on the cost of the chemical products, bleaching process yields and on minimizing the environmental impact of the bleaching process. In spite of some process restrictions, high ISO brightness levels were kept around 90 % brightness. Additionally, the inclusion of stages like acid hydrolysis, pressurized peroxide and ozone in the bleaching sequences provided an increase in operating flexibility, aimed at reducing environmental impact (ECF Light). The Dhot(EOP)D(PO) sequence presented lower operating cost for ISO brightness above 92 %. However, this kind of sequence was not allowed for closing the wastewater circuit, even partially. For ISO brightness level around 91%, the AhotZhcDP sequence presented a lower operating cost than the others

Brazilian Journal of Chemical Engineering, 2009, vol. 6, núm.1, p.11 - 22

Associação Brasileira de Engenharia Química

Author: Costa, M.M.
Santos, C.A.
García, J.C.
Barberà, L.
Vilaseca Morera, Fabiola
Pèlach Serra, Maria Àngels
Mutjé Pujol, Pere
Colodette, J.L.
Date: 2009
Abstract: The alternatives used for minimizing the usage of chlorine dioxide in bleaching sequences included a hot acid hydrolysis (Ahot) stage, the use of hot chlorine dioxide (Dhot) and ozone stages at medium consistency and high consistency (Zmc and Zhc), in addition to stages with atmospheric hydrogen peroxide (P) and pressurized hydrogen peroxide (PO). The results were interpreted based on the cost of the chemical products, bleaching process yields and on minimizing the environmental impact of the bleaching process. In spite of some process restrictions, high ISO brightness levels were kept around 90 % brightness. Additionally, the inclusion of stages like acid hydrolysis, pressurized peroxide and ozone in the bleaching sequences provided an increase in operating flexibility, aimed at reducing environmental impact (ECF Light). The Dhot(EOP)D(PO) sequence presented lower operating cost for ISO brightness above 92 %. However, this kind of sequence was not allowed for closing the wastewater circuit, even partially. For ISO brightness level around 91%, the AhotZhcDP sequence presented a lower operating cost than the others
Format: application/pdf
ISSN: 0104-6632
Document access: http://hdl.handle.net/10256/8610
Language: eng
Publisher: Associação Brasileira de Engenharia Química
Collection: Reproducció digital del document publicat a: http://dx.doi.org/10.1590/S0104-66322009000100002
Articles publicats (D-EQATA)
Is part of: Brazilian Journal of Chemical Engineering, 2009, vol. 6, núm.1, p.11 - 22
Rights: Attribution-NonCommercial 3.0 Spain
Rights URI: http://creativecommons.org/licenses/by-nc/3.0/es/
Subject: Cel·lulosa
Cellulose
Paper -- Blanqueig
Paper -- Bleaching
Title: Low environmental impact bleaching sequences for attaining high brightness level with eucalyptus SPP pulp
Type: info:eu-repo/semantics/article
Repository: DUGiDocs

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