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), extractives and carbonyl groups in the...

Steam explosion has been proposed for a wide range of lignocellulosic applications, including fractionation of biomass, pre-treatment of biomass for ethanol production, or as an alternative to conventional mechanical pulping. Nevertheless, a steam explosion process could also be used as pretreatment before chemical pulping, expecting a reduction in cooking time due to the open structure of the ...

Background The species of the genus Eucalyptus are the most planted for the fiber crop in the world. They are mainly utilized for timber, pulp and paper production. Brazil, helped by the favorable weather conditions, appears as a big producer and exporter of eucalyptus derivates. In 2002, the Brazilian network research of the Eucalyptus Genome (Genolyptus) was established with the goal of integ...

The extraction of hemicelluloses prior to pulping is an attractive process to be incorporated in the pulp and paper mills to generate valuable by-products such as xylose and xylo-oligomers in addition to core products. This paper investigates the impact of xylan extraction by dilute acid on cooking conditions, pulp yield and properties during kraft and soda-AQ pulping of Eucalyptus grandis wood...

In this study, multifunctional alkaline pulping was suggested to produce different pulp grades at one mill site, ranging from high-yield paper pulp to high-purity dissolving pulp. In all process modifications, sulfur was successfully replaced by anthraquinone. Autohydrolysis and alkaline pre-extraction were applied to Eucalyptus globulus wood chips, followed by kraft and soda-AQ pulping. Alkali...

Pulp concentration was increased, during preparation of microfibrillated cellulose (MFC), in an effort to improve the efficiency of cellulase pretreatment. It was hypothesized that increased pulp concentration could possibly increase the interactions between cellulase and cellulose, therefore improving the cellulase pretreatment efficiency and benefiting MFC and its film properties. Results sho...

Background Eucalyptus spp. is a genus widely planted in many tropical and subtropical regions of the world as a major source in the production of pulp and paper. Aiming to meet the demand required by the world market papermaker, with the need for greater productivity in forests, as well as higher quality of wood, reducing the amount of lignin and extractive, is that proteomics emerges as an add...

The delignification efficiency of different laccase enzymes was examined on the eucalyptus Kraft pulp. The laccase enzyme from Trametes versicolor showing the highest delignification efficiency was selected and used in the elemental chlorine-free bleaching sequence for improving the pulp bleachability. An appreciable reduction in chlorine dioxide consumption was also obtained. Further reduction...

Background Brazil stands on the international scenario by having one of the largest natural forest heritage and extensive sustainable planted forests. Brazilian planted forestry is based mainly on fast growing eucalyptus and pines, with the pulp, paper and steel industries as the major consumers. Introduced commercially in Brazil in the early twentieth century, the eucalypts have experienced in...