Effects of Tween-80 and Alkali Pretreatment on the Content of Lignin of Straw and Enzymatic Hydrolysis

The effects of alkali pretreatment conditions on the content of lignin,cellulose of straw by addition of tween-80 at 1‰ were studied,the crystallinity of straw before and after pretreatments was estimated by X-ray diffraction(XRD),effects of different pretreatments on variations of composition and enzymatic hydrolysis of cellulose were seen from the results.The results show that the content of lignin was 6.5%(41.9% lower than the untreated sample) and the content of ash was merely 6.9% by pretreatment(4% NaOH by addition of Tween-80 at 1‰,30 ℃),this pretreatment was applied to get rough feed;the content of lignin was 2.8%(74.5% lower than the untreated sample) by alkaline pretreatment(4% NaOH by addition of Tween-80 at 1‰,121℃),the maximum yield of reducing sugars from rice straw was 393.9 mg per g and the ratio of conversion of cellulose was 59.3%(increasing 2.4 times than the untreated sample).XRD showed that after the low concentration of alkali pretreated rice straw in relatively mild conditions,crystalline of cellulose was destroyed weaker than amorphous area,therefore it was not enough to decrease the crystallinity index(CrI) of cellulose.