Fernando E. Felissia

The influence of pulping and washing conditions on the properties of Eucalyptus grandis unbleached kraft pulps treated with chelants.

The influence of different addition points of a chelating agent and a counter-ion exchange on the properties of Eucalyptus grandis unbleached kraft pulps is studied. Seven pulps were considered: two laboratory kraft pulps with or without the inclusion of the chelant DTPMPA (diethylene triamine penta (methylene phosphonic acid)), a mill kraft pulp and four mill pulps after Ca(+2) or Na(+) counter-ion exchange followed, or not, by washing with DTPMPA addition. The laboratory pulps required lower beating energy than the industrial pulps for achieving 30 degrees SR, and the corresponding handsheets also showed better strength and optical properties, as well as a more homogeneous and smooth surface. The counter-ion exchange decreases the mechanical resistances and increases brightness. However, the effects of Ca(+2) are deeper than those of Na(+). DTPMPA added to pulping causes a decrease in calcium content whereas as a washing additive does not have a relevant impact on the mechanical and optical properties.

Alternatives of Small-Scale Biorefineries for the Integrated Production of Xylitol from Sugarcane Bagasse

Fil: Clauser, Nicolas Martin. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Quimicas y Naturales. Instituto de Materiales de Misiones; Argentina

Scaling in Alkaline Spent Pulping Liquor Evaporators

This chapter discusses the fouling that occurs in evaporators used to concentrate the black liquor in kraft pulp mills. Initially, the chemical nature of black liquors and the location of the recovery process within the framework of the kraft mill are briefly described. It includes an explanation about the different types of fouling and how they evolved over time due to changes that were made in the pulping process and due to evaporation technologies. It also describes the nature of the deposits and various proposals for mitigation. Finally, a series of case studies is presented.