Two-Step Decomposition Behavior of Rice Straw as Treated by Semi-Flow Hot-Compressed Water

• OGURA Mai

  Graduate School of Energy Science, Kyoto University

• PHAIBOONSILPA Natthanon

  Graduate School of Energy Science, Kyoto University

• YAMAUCHI Kazuchika

  Graduate School of Energy Science, Kyoto University

• SAKA Shiro

  Graduate School of Energy Science, Kyoto University

Bibliographic Information

Other Title

• 半流通型２段階加圧熱水処理による稲わらの分解挙動

Abstract

Decomposition behavior of rice (Oryza sativa) straw, as one of the monocotyledonous angiosperms, was investigated under the two-step semi-flow hot-compressed water at 230°C/10 MPa/15 min (1st stage) and 270 °C/10 MPa/30 min (2nd stage). Prior to the hot-compressed water treatment, cold-water extraction at 20°C/10 MPa/30 min was performed. It was consequently found that some inorganic constituents and free neutral sugars such as xylose, arabinose, glucose and mannose, which would not be chemically bonded with the plant cell wall, were recovered in the cold-water extractives. On the other hand, in the 1st stage, hemicellulose, pectin and para-crystalline cellulose, whose crystalline structure is somewhat disordered, were selectively hydrolyzed, as well as lignin being partially decomposed. In addition, protein was found to be hydrolyzed and formed into various amino acids. Hydrolysis of crystalline cellulose was, however, observed in the 2nd stage. Some additional decomposition of lignin and protein was revealed at this stage as well. In total, 97.9% of oven-dried extractives-free rice straw sample could be solubilized into cold and hot-compressed water. Various products in the water-soluble portion were primarily recovered as saccharides (hydrolyzed products of the polysaccharides), which were partially isomerized and then dehydrated and fragmented. The 2.1% of residue after the treatment was composed mainly of lignin and a trace of silica.

Journal

• Journal of the Japan Institute of Energy

  Journal of the Japan Institute of Energy 92 (4), 319-326, 2013

  The Japan Institute of Energy

Keywords

• Rice straw
• Monocotyledonous angiosperm
• Lignocelluloses
• Hot-compressed water
• Hydrolysis

Details

• CRID: 1390282679335586944
• NII Article ID: 130004541059
• DOI: 10.3775/jie.92.319
• ISSN: 18826121
• ISSN: 09168753
• Text Lang: ja
• Data Source:
  • JaLC
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed