Kappa number and viscosity in oxygen delignification of kraft-pulp Eucalyptus pellita in comparison with prediction data

The quality of pulp after delignification process is measured by the lignin content (Kappa Number) and viscosity (pulp strength). In this study, Eucalyptus Pellita was treated in Kraft process followed with oxygen delignification. The resulting pulp was then analyzed in term of Kappa number and viscosity. The aim of this work was to develop kinetic empirical model of oxygen delignification reaction and compare the Kappa number and viscosity obtained from experimental data with those from kinetic model. The experimental data was collected by varying the operating conditions of oxygen pressures, temperatures, alkali concentrations and heating times. The Kappa number decreased with the increasing of alkali concentration, oxygen pressure, temperature, and heating time, as well as for the viscosity. The value of both Kappa number and viscosity obtained from kinetic model were close enough to that obtained from experiment. Therefore, the kinetic model could be used to predict the optimum condition in oxygen delignification of kraft-pulped.