蔗渣浆的压力过氧化氢漂白

对烧碱-蒽醌(Soda-AQ)法蔗渣浆分别进行了螯合预处理(Q)和常压过氧化氢(P)、压力过氧化氢(PO)漂白的研究,探讨了单段PO漂白蔗渣浆的可行性.正交试验结果表明,PO漂白蔗渣浆优化的漂白条件为漂白温度100℃、时间80min、压力0.6MPa、NaOH用量0.4%.PO漂白浆的白度较高,达84.0%ISO,特性黏度为825.3mL/g,比QP漂白浆的白度高9.9%ISO;PO漂白浆的物理强度性能也较好,浆料的抗张指数为66.67N.m/g,撕裂指数为9.34mN.m2/g,耐破指数为4.31 kPa.m2/g,耐折度为39次.PO漂白废水的化学耗氧量、生化耗氧量及色度较低,漂白废水可全部逆流回用,大大减少了污染排放.

Pressured Hydrogen Peroxide Bleaching of Bagasse Pulp

Two shot bleaching sequences,namely QP(chelating pretreatment and hydrogen peroxide bleaching) and PO(pressured hydrogen peroxide bleaching),were performed for Soda-AQ bagasse pulp,and the possibility of single-stage PO for bagasse pulp was discussed.Then,orthogonal tests were carried out and the optimal PO conditions were determined,that is,a temperature of 100 ℃,a duration of 80 min,an oxygen pressure of 0.6 MPa and a NaOH dosage of 0.4%.It is found that the viscosity of the PO-bleached pulp reaches 825.3 mL/g and the brightness is up to 84.0% ISO,which is 9.9% ISO higher than that of the pulp with QP sequence,and that the PO-bleached pulp is a kind of high-strength pulp with a tensile index of 66.67 N·m/g,a tear index of 9.34 mN·m2/g,a burst index of 4.31 kPa·m2/g and a folding endurance of 39 times.Moreover,it is indicated that PO helps to greatly reduce the pollution discharge because PO effluent can be totally countercurrent reused in the bleaching stage due to its low chemical oxygen demand,biochemical oxygen demand and chroma.