Aplicação do ácido peracético no branqueamento da polpa de eucalipto e o impacto na sua qualidade

• Autor(a) principal: Barros, Denise Pires de
• Data de Publicação: 2008
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2072
• topic: Ácido peracético; Eucalipto; Branqueamento; Polpa kraft; Qualidade; Peracetic acid; Eucalyptus; Bleaching; Kraft pulp; Quality; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA ORGANICA

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 impact of the last stage of bleaching with peracetic acid in refinery and physical-mechanical properties of the eucalyptus pulp. The evaluated sequences were D(EP)D/Paa, DHT(EP) D/Paa, D/QP/Paa and Z/ED/Paa. The use of peracetic acid, as final stage of bleaching in those sequences, was not economically viable in relation to the cost of chemical bleaching reagent, resulting in the decrease in pulp viscosity and not bringing environmental benefits when judged by the color, COD (Chemical Demand Oxygen) and AOX (Adsorbable Organic Halogens) of the effluent, regardless of the bleaching sequence. The bleaching sequence that presented best potential was Z/EDP, for which the conversion of DP final stages into D/Paa raised the bleaching cost in just $ 3.5/ tonne of pulp, what would be offset by reducing the investment by the elimination of a washing stage. The sequence D/QP/Paa stands out from the others by the better pulp quality. However, the sequence presented a high bleaching cost.