爆炸冲击波联合碱预处理提高玉米秸秆糖化率的研究

STUDY ON DIGESTBILITY ENHANCEMENT OF CORN STOVER BY SHOCKWAVE COMBINED WITH ALKALI PRETREATMENT

采用爆炸冲击波联合碱处理的方法来提高玉米秸秆的酶解糖化效率。选择爆炸初始压力、碱用量和碱处理温度及时间等主要影响因素,进行单因素和正交试验以获得最优的处理工艺条件。预处理后的秸秆中分别加入2 mg/g(酶/秸秆)的纤维素酶和半纤维素酶,进行酶水解反应5 d,采用高效液相色谱(HPLC)测定其中葡萄糖和木糖浓度从而计算糖化率。结果表明,对糖化率影响程度从大到小依次为碱处理温度、碱用量、碱处理时间和爆炸初始压力。当采用最优实验条件:初始压力550 kPa、碱浓度为8%NaOH、碱处理温度为100℃、碱处理时间为60 min,玉米秸秆糖化率可达0.643。爆炸冲击波-碱联合处理玉米秸秆比单纯使用碱处理时,糖化率可提高8%~12%。

Shockwave and alkali treatment were combined to enhance the digestibility of corn stover.Initial shock pressure,hydroxide concentration,alkali treatment temperature,and alkali treatment time were investigated to determine their effects on digestibility.Orthogonal experiments were conducted to find the optimal conditions for digestibility.After performing shock and alkali pretreatment adding 2 mg/g(enzyme/straw)cellulase and hemicellulase respectively,the corn stover was enzymatically hydrolyzed for 5 days,and then the sugar concentration were measured with HPLC for calculating the digestibility.The results show that alkali treatment temperature has the greatest effect on digestibility followed by hydroxide concentration,alkali treatment time and initial shock pressure.A maximum digestibility of 0.643 is found under the following conditions:550 k Pa of initial shock pressure,8% OH-,100℃ of alkali treatment temperature,and 60 minutes of caustic treatment time.The digestibility of corn stover treated with shockwave and alkali can be increased by 8%-12% compared with that treated with alkali alone.