杨木NS-AQ法高得率化学浆强化氧脱木素的效果

Reinforced Oxygen Delignification of NS-AQ High-Yield Chemical Pulp of Aspen

研究了H2 O2 强化 (Op)及用尿素浸渍后的H2 O2 强化 (Opu)氧脱木素对杨木NS AQ法高得率化学浆氧脱木素效果的影响。结果表明 ,H2 O2 使氧脱木素的反应选择性提高 ,H2 O2 用量 2 % ,浆的卡伯值下降 2 0 % ,粘度提高 8 5% ,白度提高 6 8个百分点 ,返黄值由 1 1 3下降到 0 4 3。Opu与Op比较 ,白度提高 4 7个百分点 ,返黄值由 0 4 3下降到 0 2 1。但脱木素选择性较差 ,在卡伯值相当的情况下 ,粘度和得率有所下降。光谱分析表明 ,Op对木素的氧化性高于Opu 。

The effect of H2O2 reinforcement (Op) and H2O2 reinforcement after urea impregnation (Opu) on the oxygen delignification efficiency of the NS-AQ high-yield chemical pulp of aspen was studied. The results indicated that the reaction selectivity of oxygen delignification is raised by adding H2O2, the kappa number of the oxygen delignified pulp decreases by 20%, intrinsic viscosity increases by 8.5%, and brightness increases by 6.8 points, and yellowing value decreased from 1.13 to 0.43 under the charge of H2O2 2%. Comparing with Op, the brightness of Opu increases 4.7 points, yellowing value decreases from 0.43 to 0.21. But the selectivity of delignification of Opu is lower than Op, the intrinsic viscosity and yield of Opu are lower at the same kappa number. The results of chromatographic analysis showed that the power of oxidizing lignin of Op is higher than Opu, and the residual lignin of pulp treated with Op contains more oxy-radical than the pulp treated with Opu.