直接精馏法提取纤维素乙醇

Extraction of ligno-cellulosic bio-ethanol by direct distillation

采用直接精馏法研究了高固含量(质量分数)、高黏度的玉米秸秆发酵醪液的精馏工艺,设计了带搅拌桨的不锈钢筛板-填料精馏塔,确定了固含量为11.56%的发酵醪液的幂律模型本构方程,进而得到塔釜中发酵醪液的黏度和搅拌桨转速的关系。在进料量为2.7 L/h、进料体积分数为10%左右、进料温度为30℃、操作压力为常压的条件下,考察了进料位置、回流比、搅拌桨转速等操作条件对纤维素乙醇精馏的影响。实验结果表明:第27块塔板进料、操作回流比5.0、搅拌桨转速36 r/min为最佳操作条件,塔顶乙醇收率可达到99%以上。

The distillation process of corn stover fermentation slurry with high solid loading and high viscosity was studied by direct distillation, and the steel tray-packing distillation column with mixing propeller was designed. The power law module of fermentation slurry with solid loading （mass fraction） of 11.56% was given, and the relation between viscosity of fermentation slurry and rotational speed of mixing impeller was established. The effect of feed location, reflux ratio, rotational speed of mixing propeller on ligno-cellulosic bio-ethanol distillation was observed at feed flow rate 2.7 L/h, feed volume fraction about 10% , feed temperature 30 ~C and normal pressure. The results show that under the optimum conditions of 27th feed plate, reflux ratio 5.0 and rotational speed of mixing impeller 36 r/rain , the overhead ethanol yield can reach above 99%.