Isolation and structural characterization of sugarcane bagasse lignin after dilute phosphoric acid plus steam explosion pretreatment and its effect on cellulose hydrolysis

• Published in: Bioresource technology Vol. 154; pp. 274 - 281
• Main Authors: Zeng, Jijiao, Tong, Zhaohui, Wang, Letian, Zhu, J.Y., Ingram, Lonnie
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.02.2014; Elsevier
• Subjects: Bagasse; Biological and medical sciences; Biomass; Biotechnology - methods; Cellulase - metabolism; Cellulose; Cellulose - chemistry; Cellulose - metabolism; Cellulose hydrolysis; Ethanol; Ethanol - chemistry; Ethyl alcohol; Extraction; Food industries; Fundamental and applied biological sciences. Psychology; Glucose - biosynthesis; Hydrolysis; Lignin - chemistry; Lignin - isolation & purification; Lignin structure; Magnetic Resonance Spectroscopy; Molecular Weight; Nuclear magnetic resonance (NMR); Phosphoric Acids - chemistry; Pretreatment; Saccharum - chemistry; Soluble lignin; Steam; Steam explosions; Use and upgrading of agricultural and food by-products. Biotechnology; Cellulose hydrolysis; Lignin structure; Soluble lignin; Nuclear magnetic resonance (NMR); Phosphoric acid; Lignin; Cellulose; Solubility; Hydrolysis; Sugar cane(by product); Bagasse; Thermal explosion; Pretreatment; Nuclear magnetic resonance
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2013.12.072

•The structure of lignin after phosphoric pretreatment was elucidated.•Lignin reserved basic structure and molecular weight after pretreatment.•Lignin after pretreatment contained relatively lower β-O-4 linkages.•The removal of ethanol extracted lignin increased ∼22% glucose yield. The structure of lignin after dilute phosphoric acid plus steam explosion pretreatment process of sugarcane bagasse in a pilot scale and the effect of the lignin extracted by ethanol on subsequent cellulose hydrolysis were investigated. The lignin structural changes caused by pretreatment were identified using advanced nondestructive techniques such as gel permeation chromatography (GPC), quantitative 13C, and 2-D nuclear magnetic resonance (NMR). The structural analysis revealed that ethanol extractable lignin preserved basic lignin structure, but had relatively lower amount of β-O-4 linkages, syringyl/guaiacyl units ratio (S/G), p-coumarate/ferulate ratio, and other ending structures. The results also indicated that approximately 8% of mass weight was extracted by pure ethanol. The bagasse after ethanol extraction had an approximate 22% higher glucose yield after enzyme hydrolysis compared to pretreated bagasse without extraction.