| 摘要: |
| 【目的】优化小麦和玉米秸秆的亚临界水处理条件，并考察最优条件下处理残渣的酶解和发酵特性。【方法】采用亚临界水法分别处理小麦和玉米秸秆，以水可溶部分的总还原糖含量为响应值，通过中心组合设计优化处理温度和时间，并研究最优条件下2种原料处理后的残渣的同步酶解和发酵生产乙醇过程。【结果】小麦和玉米秸秆的最优亚临界水处理条件分别为：194 ℃，0 min和190 ℃，0 min；在此条件下，处理后小麦秸秆中的木质素、纤维素和半纤维素含量分别比处理前减少44.9%，4.9%和74.7%，处理后的玉米秸秆对应的3种成分含量分别比处理前减少34.2%，7.2%和69.5%。小麦秸秆的残渣酶解-发酵率优于玉米秸秆，小麦秸秆处理后残渣的酶解率为35%，约为处理前(6.9%)的5倍；玉米秸秆处理后残渣的酶解率为28.8%，约为处理前(9%)的3倍；小麦和玉米秸秆处理后的残渣在35 ℃下分别发酵(残渣质量分数为11%)，最终获得的乙醇质量浓度分别为12.8和10.4 g/L。【结论】亚临界水预处理能有效去除小麦和玉米秸秆中的半纤维素和木质素，保留90%以上的纤维素，提高了酶解 发酵过程的效率。 |
| 关键词: 亚临界水 小麦秸秆 玉米秸秆 乙醇 预处理 |
| DOI： |
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| 基金项目:陕西省农业科技创新项目（2010NKC-11）；陕西省自然科学基金项目（2010JQ3012）；国家教育部回国人员科研启动基金第41批项目 |
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| Optimization of wheat and corn straw pretreating process with subcritical water and investigation on bioethanol production |
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JIA Yuze, LÜ Xin
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Northwest A&F University
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| Abstract: |
| 【Objective】The research optimized the subcritical water pretreatment conditions for wheat and corn straw,and then the enzymolysis and fermentation of residuals from the pretreatment with optimal conditions were investigated.【Method】Subcritical water was employed for wheat and corn straw pretreatment and the pretreatment temperature and time were optimized by Central Composite Design for the highest total reducing sugar content in water-soluble materials,and the enzymolysis and fermentation of the residuals after pretreatment under the optimal conditions were investigated.【Result】The optimal subcritical water pretreatment temperature and time for wheat straw were 194 ℃ and 0 min and those for corn straw were 190 ℃ and 0 min,respectively.With the optimal conditions,the contents of lignin,cellulose and hemicellulose for pretreated wheat straw decreased by 44.9%,4.9% and 74.7%,respectively;while those for pretreated corn straw decreased by 34.2%,7.2% and 69.5%,respectively.Enzymolysis and fermentation rates of wheat straw were better than that of corn straw.The enzymolysis rate for pretreated wheat straw was 35%,which was 5 times more than the untreated materials (6.9%);while the enzymolysis rate for pretreated corn straw was 28.8%,which was 3 times more than untreated materials (9%).The final ethanol concentrations from residuals of wheat and corn straw fermented at 35 ℃ with mass fraction of 11% were 12.8 and 10.4 g/L,respectively.【Conclusion】Subcritical water pretreatment was effective to remove hemicelluloses and lignins while reserved more than 90% celluloses for wheat and corn straw,simultaneously enhanced their enzymolysis and fermentation. |
| Key words: subcritical water wheat straw corn straw ethanol pretreatment |
