Nitric-acid hydrolysis of <em>Miscanthus giganteus</em> to sugars fermented to bioethanol [electronic resource]

• Ngôn ngữ: eng
• Ký hiệu phân loại: 668.5 Perfumes and cosmetics
• Thông tin xuất bản: Washington, D.C. : Oak Ridge, Tenn. : United States. Dept. of Energy. Office of Science ; Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2015
• Mô tả vật lý: Size: p. 304-314 : , digital, PDF file.
• Bộ sưu tập: Metadata
• ID: 263690
• Chủ đề: 1. 09 biomass fuels; 2. 59 basic biological sciences; 3. Dilute-nitric-acid hydrolysis; 4. Miscanthus giganteus; 5. Two-step process

Tóm tắt

 <
 em>
 Miscanthus giganteus<
 /em>
  (<
 em>
 M. giganteus<
 /em>
 ) is a promising feedstock for the production of bioethanol or biochemicals. Using only dilute nitric acid, this work describes a two-step process for hydrolyzing hemicellulose and cellulose to fermentable sugars. Primary variables were temperature and reaction time. The solid-to-liquid mass ratio was 1:8. No enzymes were used. In the first step, <
 em>
 M. giganteus<
 /em>
  was contacted with 0.5 wt.% nitric acid at temperatures between 120 and 160�C for 5 to 40 min. The second step used 0.5 or 0.75 wt.% nitric acid at temperatures between 180 and 210�C for less than 6 min. Under selected conditions, almost all hemicellulose and 58% cellulose were transferred to the liquid phase. Small amounts of degradation products were observed. The xylose solution obtained from the nitric-acid hydrolysis was fermented for 96 h and the glucose solution for 48 h to yield 0.41 g ethanol/g xylose and 0.46 g ethanol/g glucose. To characterize residual solids and the liquor from both steps, nuclear-magneticresonance (NMR) spectroscopy was performed for each fraction. In conclusion, the analytical data indicate that the liquid phase from Steps 1 and 2 contain little lignin or lignin derivatives.