In situ pretreatment during distillation improves corn fiber conversion and ethanol yield in the dry mill process
In situ pretreatment during distillation improves corn fiber conversion and ethanol yield in the dry mill process
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蒸馏过程中的原位预处理可提高干磨过程中的玉米纤维转化率和乙醇产量
DOI：
10.1039/c8gc03447h
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发表时间：
2019-03-07
期刊：
影响因子：
9.8
通讯作者：
Jin, Mingjie
中科院分区：
文献类型：
--
作者：
Li, Xiujuan;Xu, Zhaoxian;Jin, Mingjie
生物乙醇是目前市场上的主要生物燃料，在美国和中国，生物乙醇主要是通过干磨工艺从玉米淀粉中生产的。与淀粉相反，存在于玉米粒中的玉米粒纤维（主要是纤维素和半纤维素）在传统方法中保持未转化。目前，正在开发转化玉米纤维以提高乙醇产量的技术。在这项工作中，在蒸馏过程中开发了一种原位酸预处理方法，并将其集成到干磨工艺中。将预处理的釜馏物在发酵期间加入纤维素酶的情况下再循环至液化步骤，或者使用纤维素酶水解，然后再循环至液化步骤，或者使用纤维素酶水解，然后进行C6/C5糖共发酵。结果表明，与传统干磨工艺相比，预处理酒糟的C6/C5糖共发酵使乙醇产率提高了3.8%-6.3%，纤维素转化率为52.7%-77.5%。回收40%的全釜馏物或水解物导致总乙醇产率增加4.6%-7.9%，纤维素转化率为56.0%-69.2%。这项工作表明，将预处理和蒸馏集成在一个步骤中是通过节省能源和资本支出将玉米纤维转化为乙醇的有效方法。
Bioethanol is currently the major biofuel in the market, which is mostly produced from corn starch through the dry-mill process in the US and China. In contrast to the starch, the corn kernel fiber (mostly cellulose and hemicellulose) present in corn grain remains unconverted in the traditional process. Currently, technologies are being developed to convert corn fiber to boost the ethanol yield. In this work, an in situ acid pretreatment method was developed during distillation and was integrated into the dry-mill process. The pretreated stillage was either recycled to the liquefaction step with the addition of cellulase during fermentation or hydrolyzed using cellulase and then recycled to the liquefaction step or hydrolyzed using cellulase followed by C6/C5 sugar co-fermentation. As a result, C6/C5 sugar co-fermentation of the pretreated stillage improved the ethanol yield by 3.8%-6.3% compared to the traditional dry mill process, with cellulose conversion of 52.7%-77.5%. Recycling of 40% whole stillage or hydrolysate resulted in a 4.6%-7.9% increase in the total ethanol yield, with cellulose conversion of 56.0%-69.2%. This work demonstrated that integrating pretreatment and distillation in a single step is an efficient way to convert corn fiber into ethanol by saving energy and capital expenditure.