预处理苎麻秆和红麻秆糖化发酵生产燃料乙醇

Pretreatment of ramie and kenaf stalk for bioethanol production

摘要:

苎麻和红麻是我国传统纤维作物，皮部纤维在造纸、纺织等工业具有广泛用途，但剥皮后剩余的茎秆部分并没有被有效利用。由于其中含有较多纤维素，可望被生物转化生产燃料乙醇。比较了几种不同化学预处理方法对苎麻秆和红麻秆纤维素酶解性能的改善效果，进而选择碱法预处理后原料，进行半同步糖化发酵产乙醇实验。结果表明，苎麻秆和红麻秆经4% NaOH和0.02%蒽醌-2-磺酸钠盐 (AQSS)，在170 ℃下处理1 h，继而在固形物底物浓度18%时发酵168 h，发酵液中乙醇浓度达到51 g/L。采用少量多次补料至20%的底物浓度，乙醇浓度都能达到63 g/L，纤维素转化率分别为77%和79%。红麻秆经5.2% NaHSO3和0.2% H2SO4，在170 ℃下处理1 h，补料至20%的底物浓度时，乙醇浓度可达到65 g/L，纤维素转化率为72%。

Abstract:

Ramie and kenaf were traditional fiber crops in China, but their stalk after decorticating has not been used effectively. The stalk contains a lot of cellulose, and can therefore be used for the production of bioethanol. We studied the effects of different chemical pretreatment on enzymatic digestibility of ramie stalk and kenaf stalk. Ramie and kenaf stalks pretreated with alkali were chosen to produce ethanol using quasi-simultaneous saccharification and fermentation (Q-SSF) process. The results show that for the stalks pretreated with 4% NaOH and 0.02% anthraquinone-2-sulfonic acid sodium salt (AQSS) as catalyzer at 170 ℃ for 1 h, the ethanol concentration could reach 51 g/L after fermentation for 168 h at 18% of solid substrate concentration. By fed-batch to 20% of solid substrate concentration, the ethanol concentration could reach 63 g/L, 77% and 79% of the cellulose conversion could get for ramie stalk and kenaf stalk, respectively. For kenaf stalk pretreated with 5.2% NaHSO3 and 0.2% H2SO4 at 170 ℃ for 1 h, the ethanol concentration and cellulose conversion could reach to 65 g/L and 72%, respectively.