Optimization ofsaccharification yield of wood-cellulosic material for bio-ethanol production through mechanical treatment

木材纤维素材料的细破碎机（研磨机）的原型已经被构造成具有彼此独立旋转的甩刀和旋转筛。将竹子分批送入细粉碎机，然后用加压热水（亚临界水）处理粉碎的材料以改变其结构，然后用酶水解成葡萄糖。随着筛孔直径的增加，细粉碎比能从500 kJ/kg显著降低到250 kJ/kg，而200°C时的葡萄糖产率从38%降低到35%。最佳转子转速为1500 rpm，筛孔直径为4 mm。此外，测试了6 mm和8 mm的筛孔直径以降低比能量需求，并且酸性水解显示，由于产生的材料太大，这样的大孔显著降低了葡萄糖产率。在2400 rpm的转子速度下的试验显示，产生更细的材料并且净能量需求没有增加。这意味着需要进一步开发细破碎机以在降低的能量需求下增加葡萄糖产量。附加实验的结果部分得到了在细破碎机中拍摄的高速视频电影的支持。

A prototype of a fine-crusher (grinder) of wood-cellulosic materials has been constructed with flail-knives and a rotary sieve rotating independently of each other. Pieces of bamboo in batches were fed into the fine-crusher, the crushed material was then treated with pressurized hot water (sub-critical water) to modify its structure and then hydrolyzed into glucose with an enzyme. With an increase in the diameter of the pores of the rotary sieve, the specific energy requirement for fine-crushing decreased remarkably from 500 to 250 kJ/kg, whilethe estimated glucose yield at 200°C decreased negligibly from 38% to 35%. The best rotational speed of the rotor and the diameter of the sieve pores were 1500 rpm and 4 mm, respectively. Additionally, sieve pore diameters of 6 mm and 8 mm was tested to reduce the specific energy requirement, and the acidic hydrolysis showed that such large pore significantly decreased the glucose yield due to too large material produced.A trial at a rotor speed of 2400 rpm showed that finer material was produced and the netenergy requirement did not increase, which implied that further development of the fine-crusher was needed to increase glucose yield at the reduced energy requirement. The results of the additional experiments were partly supported by high-speed video movies taken in the fine-crusher.