水洗脱毒酸性蒸汽爆破玉米秸秆制备乙醇(英文)

Ethanol Production from Detoxified Acid Steam Exploded Corn Stover by Washing

研究了水洗对酸性蒸汽爆破玉米秸秆抑制物脱除、酶水解性能和水解液发酵性能的影响。结果表明,固液比为1∶7.5(g∶mL,下同)的水洗能脱除50%以上的碳水化合物降解产物和70%以上的木质素降解产物,明显提高水解糖液发酵性能和降低发酵所需的酵母用量。蒸汽爆破预处理物料经固液比为1∶7.5的水洗,酶解、固液分离、蒸发浓缩后经酿酒酵母在用量为OD6003.84下发酵48 h,170.69 g/L葡萄糖被转化为80.67 g/L乙醇,乙醇产率为173 g/kg(以绝干预处理物料计,下同)。在固液比为1∶7.5的水洗后的带渣发酵中,106.64 g/L葡萄糖被转化为54.5 g/L乙醇,其乙醇产率为162.17 g/kg,其酵母用量为1.0×107cfu/mL(以酶解渣计)。

The effects of water-washing on inhibitors removal,enzymatic hydrolysis and fermentation of acid steam-exploded corn stover were investigated.The results revealed that the washing process （solidto-liquid ratio of 1 ∶ 7.5,room temperature） removed more than 50 ％ of the carbohydrate degradation products and more than 70 ％ of lignin degradation products.The washing process obviously enhanced the fermentability of the concentrated enzymatic hydrolysate and decreased yeast inoculum in fermentation.The concentrated hydrolysate containing 170.69 g/L glucose,which was hydrolyzed,solid-liquid separation and concentrated from washing pretreated corn stover at solidto-liquid ratio of 1 ∶ 7.5（g∶ mL）,was fermented by Saccharomyces cerevisiae with a low initial yeast inoculation of OD600 3.84 for 48 h.80.67 g/L ethanol and 93.66 ％ of ethanol yield were obtained,respectively.The corresponding ethanol production was 173.00 g based on 1 000 g dry pretreated corn stover.The whole enzymatic hydrolysate of the washed substrate at a substrate loading of 350 g/L with a yeast inoculum of 1.0 × 107 cfu/mL hydrolysate was fermented for 48 h.54.50 g/L ethanol was formed from 106.64 g/L glucose,and the corresponding ethanol production was 162.17 g based on 1 000 g pretreated dry corn stover.