Straw Blasting The Bleaching Of Pulp Green

The shortage of material for paper making will last for years. Non-wood fiber especially wheat straw will be important component of materials for paper making. Steam explosion pulping is a new kind of method for pulp making, with its high yield, good physical properties, low energy consumption and low pollution discharges. But the low level of brightness limit its usage. Few researchers focus their eyesight on the bleaching of wheat straw pulp. In this paper, the bleachablity of exploded pulp from wheat straw was studied.The research showed that exploded pulp could be bleached with OQP bleaching.Through the study of bleaching on wheat straw, it was found that oxygen delignification conditions, namely pulp consistency 5%, NaOH charge 14%, MgSO₄ 0.5%, O₂ pressure 0.8MPa, 140°C and 2 hours, resulted in better effect of delignification and small loss of fiber.The Optimal process conditions of H₂O₂ bleaching are: consistency 10%, H₂O₂ 3%, Na₂SiO₃ 3%, MgSO₄ 0.5%, the brightness reached 30%SBD.Pressurized/high temperature peroxide bleaching of wheat straw pulp was carried out, The optimal process conditions of H₂O₂ bleaching are: consistency 10%, H₂O₂ 3%, Na₂SiO₃ 3%, MgSO₄ 0.5%, the brightness reached 30%SBD. The research showed that the effect of transition metal ions on hydrogen peroxide bleaching of non-wood pulps was notable. Pretreatment to decrease the contents of Cu²⁺ and Mn²⁺ is unavoidable. The mechanism of action is studied.