Production of high quality pulp from bagasse by using non- conventional pulping and bleaching methods

Abstract

The most important parameters that affect the ASAM pulp properties are the methanol charge, chemical charge, alkali ratio and cooking time . That methanol concentration at which pronounced improvements of the delignification process occured is considered to be the optimum methanol charge. This optimum concentration depends on the type of the supporting alkali. For ASAM I cooks (NaOH is the supporting alkali), the optimum methanol charge was 15%. For . ASAM II and mixture (Na2C03 and NaOH + Na2C03, respectively) 20%

methanol was optimum . After determination of the optimum methanol charge cooking experiments have been achieved at different reaction times and that time at which a favourable yield to kappa number relationship exists and no deterioration of the pulp properties , especially the viscosity , occurs, is considered to be the appropriate cooking time. This time was 120 min for ASAM I and 150 min for both ASAM II and mixture. It has been also found that the delignification rate is very fast in the initial cooking stage for all ASAM alternatives, then slowed down gradually . It was obvious that ASAM delignification can be extended without deterioration of the viscositiy .