CHEMICAL CELLULOSE FROM STEAM-EXPLODED WOOD BY PERACETIC-ACID TREATMENT

Water and alkali-extracted steam-exploded yellow poplar (Liriodendron tulipifera) fibre was purified (delignified) with acetic acid and hydr ogen peroxide, aqueous alkali and alkaline peroxide in a multi-stage p rocess (adopted from the Finnish Pulp and Paper Research Institute). T he effects of the different parameters involved in this treatment (tem perature of bleaching, the acid concentration, the peroxide charge, an d the reaction time) were investigated using the measures of brightnes s, molecular weight, and sugar composition. The results indicated that steam-exploded wood may be a useful raw material for chemical cellulo se. Molecular weights (DP(w)) were between 300 and 550, or approximate ly 40 to 50% of unbleached cellulose from steam-exploded wood. Glucose contents exceeded 90% and residual hemicellulose content (based on xy lose content) was approximately 1.7%. Final brightness level of 75% Mg O standard was obtained with approximately 13% H2O2 consumption on ini tial fibre solids.