This paper deals with the characterization of brewer’s spent grain (BSG) and the optimization of the phosphoric acid pretreatment for this feedstock. The influence of temperature and acid concentration on BSG was studied, and the optimal conditions were found to be 155 °C and 2% H₃PO₄. The use of both pretreatment and enzymatic hydrolysis together recovered 92% of total sugars in BSG, mainly solubilized in the prehydrolysate (63%). Escherichia coli SL100 fermented this mixed sugar solution containing hemicellulosic sugars and starchy glucose without previous detoxification with an ethanol yield of 0.40 g/g. Considering also the glucose released from the cellulosic structure and converted to ethanol by a simultaneous saccharification and fermentation process, an overall ethanol yield of 17.9 g of ethanol per 100 g of raw BSG was achieved. Thereby, the process configuration proposed in this work allowed 69% of the total sugars in the BSG to be converted to ethanol.

中文翻译：

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稀磷酸预处理啤酒厂废粮中的乙醇生产

本文探讨了啤酒糟的特性（BSG），以及该原料的磷酸预处理的优化。研究了温度和酸浓度对BSG的影响，发现最佳条件为155°C和2％H ₃ PO ₄。预处理和酶促水解的使用一起回收了BSG中总糖的92％，主要溶解在预水解物中（63％）。大肠杆菌SL100对这种混合糖溶液进行了发酵，该溶液含有半纤维素糖和淀粉状葡萄糖，无需事先进行解毒，乙醇收率为0.40 g / g。还考虑到从纤维素结构释放的葡萄糖并通过同时糖化和发酵过程转化为乙醇，每100克生BSG的总乙醇产量为17.9克乙醇。因此，这项工作中提出的工艺配置允许将BSG中总糖的69％转化为乙醇。