杂多酸盐对H_2O_2脱木质素的催化效应

CATALYTIC EFFECT OF HETEROPOLY ACIDS ON DELIGNIFICATIONOF KRAFT PULP WITH HYDROGEN PEROXIDE

对4种杂多酸盐———Na4[PMo11VO40]、Na5[PMo10V2O40]、Na7[P2Mo17VO62]和Na8[P2Mo16V2O62]催化的硫酸盐浆酸性H2O2脱木质素的效果进行了考察,并对Na5[PMo10V2O40]催化H2O2脱木质素的温度效应进行了探讨。结果表明,4种杂多酸盐对硫酸盐浆H2O2脱木质素均有较强的催化活性,但它们也加速了碳水化合物的降解。卡伯值降低率和粘度降低率随杂多阴离子负电荷数的增加而降低。Na5[PMo10V2O40]催化的H2O2脱木质素过程似乎呈现出"异常"的温度响应,在60℃左右卡伯值降低率最大。随着反应温度的升高,纸浆的粘度降低率增加。对于杂多酸盐Na5[PMo10V2O40]催化的H2O2脱木质素工艺,温度定为60℃最佳。

Delignification of kraft pulp with acidic hydrogen peroxide catalyzed by four heteropoly acids--Na4\PMo11VO40\],Na5\PMo10V2O40\],Na7\17VO62\] and Na8\P2Mo16V2O was investigated,and effects of temperature on hydrogen peroxide delignification catalyzed by Na5\PMo10V2O40\] were studied.Results indicated that all four heteropoly acids have catalytic activity for delignification of kraft pulp,but they also accelerate carbohydrate degradation.Decreases of Kappa number and viscosity of pulp decreased as electric charge number of heteropoly acids increased.The temperature response of hydrogen peroxide delignification catalyzed by Na5\PMo10V2O40\] was seemingly 'abnormal',because decrease of Kappa number at about 60 ℃ was maximal.Viscosity of pulp decreased almost linearly with increase of reaction temperature.Optimum temperature is 60 ℃ for hydrogen peroxide delignification catalyzed by Na5\PMo10V2O.