硫酸盐浆卡伯值对后续氧脱木素的影响

The Effect of Kappa Number of Eucalyptus Kraft Pulp on Subsequent Oxygen Delignification

中文关键词:  硫酸盐蒸煮  氧脱木素  高卡伯值  得率  脱木素动力学

Key Words:kraft pulping  oxygen delignification  high kappa number  yield  delignification kinetics

中文摘要:

      制备了卡伯值分别为39.9、27.3及13.4的硫酸盐桉木浆（分别表示为KP-A、KP-B及KP-C)，在一定的氧脱木素工艺条件(温度、氧压、活性碱用量及反应时间)下考察硫酸盐浆卡伯值对后续氧脱木素的影响,并建立了脱木素动力学模型。研究发现,硫酸盐浆的初始卡伯值越高,其脱木素动力学的活化能越低,整体反应速率越高；反应初期,KP-A的脱木素速率是KP-B和KP-C的1.25倍,当反应时间大于30 min后,KP-A的脱木素速率是KP-B和KP-C的2倍和6倍以上。KP-A经两段氧脱木素后的卡伯值与KP-C的相近,但得率和黏度分别比KP-C的高3.4%和3.6%,己烯糖醛酸(HexA)含量则比KP-C的低28.5%。

Abstract:

      Eucalyptus kraft pulps (KPs) with three kappa number of 39.9, 27.3 and 13.4 were prepared, namely KP-A, KP-B and KP-C respectively. The effect of kappa number of eucalyptus KP on subsequent oxygen delignification (OD) and corresponding kinetic parameters were investigated under certain OD conditions including temperature,oxygen pressure, NaOH dosage and reaction time. The result showed that the activation energy decreased with the increase of initial kappa number of the eucalyptus KP while the variation trend of reaction rate went to the opposite side. At the initial reaction stage, the OD rate of KP-A was 1.25 times higher than that of the other two pulps.When the reaction time was over 30 min, the OD rate of KP-A was twice and 6 times higher than KP-B and KP-C respectively. Kappa number of KP-A was similar to that of KP-C after two stages of OD.However, the yield and viscosity of the former were 3.4% and 3.6% higher than the latter respectively. HexA content was lower than the latter pulp by 28.5%．