桉木硫酸盐法制浆及氧脱木素优化工艺的能耗评价

Evaluation of Energy Cost on the Integrated Eucalyptus Kraft Pulping and Oxygen Delignification Process

以速生桉木为考察对象,对桉木在不同工艺条件下硫酸盐法制浆(KP)及氧脱木素过程(OD)中的能耗进行了综合研究。结合桉木硫酸盐法制浆、硫酸盐浆氧脱木素过程的数学模型,给出了达到特定纸浆脱木素程度的工艺参数计算模式;并在能耗评价过程中,引入了制浆和氧脱木素两个工段的热量回收系数(φKP和φOD);由此,使得本文的计算过程、结果更加接近企业的生产实践。研究结果表明:蒸煮段、氧脱木素工段的木素脱除量越大,或者热量回收系数越小,两个工段的能耗越高。获得相同木素含量的纸浆,联合KP-OD的工艺与单独使用KP工艺的能耗有很大差异,并受φKP和φOD的交互影响:当φOD高于0.85或当φKP较低时,联合KP-OD工艺在能耗上的优势更显著;在此条件下,采用先蒸煮至高卡伯值的KP-OD要比低卡伯值KP-OD工艺的能耗低。随制浆过程中技术的进步,各工段的能量回收系数不断提高,先蒸煮后氧脱木素及高卡伯值KP-OD工艺的能耗优势将更加明显。

In this paper, the energy consumptio cation （OD） for eucalyptus was investigated. B n of different processes of kraft ased on the models for Kappa pulping （KP） and oxygen delignifinumber in kraft pulping section and oxygen delignification, the models for process conditions which can suit for the given delignification degree were concluded in this paper; the coefficients of energy recycle at blowing out and oxygen delignification plant （ φKpand φOD ） were also taken into account, which makes the calculation and results of the energy cost be close to the reality in pulp mills. The results showed that, the higher the degree of delignification in KP and OD sections was, or the lower φand φOD was, the lower the energy cost would be. When the target Kappa numbers was the same, the en- ergy cost of KP-OD combination and KP had an obvious difference, which was affected by both φKpand φOD- The advantage of KP-OD combination was obvious when φOD 〉 0. 85 or φ was comparatively low, and the energy cost of KP-OD combination with high end Kappa number at pulping section was lower than that with low end Kappa number. With the development of pulping technologies, the coefficient of energy recycle is becoming much higher, and the advantages of KP-OD combination and KP-OD combination with high end Kappa number at pulping section will be more obvious.