Ecf Bleaching
Mostrando 1-8 de 8 artigos, teses e dissertações.
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1. Wood basic density effect of Eucalyptus grandis in the paper making
ABSTRACT The basic density is the main technical property of the wood due to the fact of the easy determination and correlation with the others wood properties. In this article, it was evaluated wood chips from a five-years-old Eucalyptus grandis in three different silvicultural treatments for pulp and paper production. First, a conventional kraft pulping wa
Matéria (Rio J.). Publicado em: 16/09/2019
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2. 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 result
Brazilian Journal of Chemical Engineering. Publicado em: 2009-03
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3. Application of peracetic acid in the eucalyptus pulp bleaching and its quality impact / Aplicação do ácido peracético no branqueamento da polpa de eucalipto e o impacto na sua qualidade
In the productive sector of cellulose the demands on the quality of the final product are too great, once the market is very competitive and globalized. The main objectives of this paper were the establishment of appropriate conditions to implement the peracetic acid as the last stage of elemental chlorine-free (ECF) bleaching sequence and assessing the impa
Publicado em: 2008
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4. The impact of kappa number composition on eucalyptus kraft pulp bleachability
Consumption of chemicals during ECF bleaching of kraft pulp correlates reasonably well with kappa number, which measures with KMnO4 the total amount of oxidizable material in the pulp. However, the method does not distinguish between the oxidizable material in residual lignin and other structures susceptible to oxidation, such as hexenuronic acids (HexAs), e
Brazilian Journal of Chemical Engineering. Publicado em: 2007-03
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5. Métodos alternativos para aproveitamentos das hemiceluloses da madeira de eucalipto na indústria de celulose kraft / Alternative methods for using eucalyptus wood hemicelluloses in the kraft cellulose industry
The search for a better use of wood in the pulp industry has fuelled interest in a more rational use of its components, particularly hemicelluloses. This study investigates the impacts of alkaline leaching and self-hydrolysis of wood chips for hemicellulose removal, as well as re-adsorption into the fibers during kraft pulping of dissolved wood solids presen
Publicado em: 2007
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6. Treatability of effluents from eucalyptus kraft pulp bleaching with acid hydrolysis/hot chlorine dioxide technologies / Tratabilidade dos efluentes de branqueamento de polpa kraft de eucalipto com tecnologias de hidrólise ácida/dióxido de cloro à quente
The aim of this study was to evaluate the impact of D, D*, A/D* and AD technologies on characteristics and treatabilities of eucalyptus kraft pulp ECF bleaching effluents, of low and high COD, and a full brightness 89-90% ISO. Two samples of eucalyptus kraft pulp pre-delignified in oxygen, a well washed one with COD 6,4 kg/t.a.s. and another not well washed
Publicado em: 2006
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7. Uso de ozônio como pré e pós-tratamento de efluentes da indústria de celulose kraft branqueada / Pre and post ozone treatment of bleached kraft pulp mill effluents
This work evaluated the combination of ozone and activated sludge for treatment of bleached kraft pulp effluents. Ozonation was done before and after biological treatment. First the influence of pH, temperature and hydrogen peroxide dose on ozonation was assessed in order to optimize treatment efficiency, which was evaluated in terms of COD, BOD5, lignin, bi
Publicado em: 2006
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8. A utilização de perácidos na deslignificação e no branqueamento de polpas celulósicas
Peracids are strong oxidant species and their use is being largely studied in the delignification and cellulose pulp bleaching. Some of them has already an industrial application, specially in non-conventional bleaching sequences like ECF (Elemental chlorine free) and TCF (Totally chlorine free). This review presents the main aspects of the structure, proper
Química Nova. Publicado em: 2001-12