title: Integrated biorefinery based on hydrothermal and alkaline treatments: investigation of sorghum hemicelluloses.
abstract: An integrated process based on hydrothermal pretreatment (HTP) and alkaline post-treatment was proposed to treat sweet sorghum stem. The structural features of the alkali-soluble hemicelluloses (ASHs) obtained from the un-pretreated and hydrothermally pretreated materials were comprehensively investigated by HPAEC, GPC, NMR, FT-IR, and TGA techniques. The ASH with the highest yield (60.6%) was obtained from the HTP residue performed at 130 °C for 1.0 h. All the results indicated that the ASHs had a more linear structure with increasing the pretreatment temperature (110-170 °C). The molecular weights of the ASHs were decreased with increasing the pretreatment temperature, suggesting that C-O bonds in the ASHs were gradually cleaved, especially at the higher temperatures (≥ 170 °C). Interestingly, the integrated process yielded more homogeneous ASHs than hemicelluloses obtained from the un-pretreated material. Based on the spectral analyses, the structure of the ASHs was assumed to be L-arabino-4-O-methyl-D-glucurono-D-xylan.
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, College of Material Science and Technology, Beijing Forestry University, Beijing 100083, China.
authors.forename: Shao-Long
authors.initials: SL
authors.lastname: Sun
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, College of Material Science and Technology, Beijing Forestry University, Beijing 100083, China.
authors.forename: Jia-Long
authors.initials: JL
authors.lastname: Wen
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, College of Material Science and Technology, Beijing Forestry University, Beijing 100083, China.
authors.forename: Ming-Guo
authors.initials: MG
authors.lastname: Ma
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, College of Material Science and Technology, Beijing Forestry University, Beijing 100083, China.
authors.forename: Xian-Liang
authors.initials: XL
authors.lastname: Song
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, College of Material Science and Technology, Beijing Forestry University, Beijing 100083, China. Electronic address: rcsun3@bjfu.edu.cn.
authors.forename: Run-Cang
authors.initials: RC
authors.lastname: Sun
mesh_terms: D000468:Alkalies / Q000737:chemistry; D005591:Chemical Fractionation; D009682:Magnetic Resonance Spectroscopy; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification; D011134:Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification; D012995:Solubility; D045868:Sorghum / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000468:Alkalies; D010936:Plant Extracts; D011134:Polysaccharides; C007916:hemicellulose
keywords: Alkaline treatment; Hemicelluloses; Hydrothermal pretreatment; Nuclear magnetic resonance (NMR); Structural feature; Sweet sorghum stem