Acid post-hydrolysis of xylooligosaccharides from hydrothermal pretreatment for pentose ethanol production. (1st December 2016)

• Record Type: Journal Article
• Authors: Nakasu, P.Y.S.; Ienczak, L.J.; Costa, A.C.; Rabelo, S.C.
• Is Part Of: Fuel. Volume 185(2016)
• Page Start: 73
• Page End: 84
• Publication Date: 2016-12-01
• Subjects: DPH detoxified post-hydrolysate -- HH hemicellulosic hydrolysate -- HPH hemicellulosic post-hydrolysate -- XO xylooligosaccharide; Sugarcane bagasse -- Pentose ethanol -- Hydrothermal pretreatment -- Post-hydrolysis -- Xylooligosaccharides; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2016.07.069
• Languages: English
• ISSNs: 0016-2361

Abstract

Graphical abstract: Highlights: The acid post-hydrolysis of a hydrothermal hemicellulosic hydrolysate was studied. The performances of three acids: oxalic, maleic and sulfuric acid was compared. The C5-rich post-hydrolysates were fermented with a wild-type yeast. Sulfuric acid showed the best kinetic of post-hydrolysis of xylooligosaccharides. Acid post hydrolysis increases overall ethanol yield from sugarcane bagasse. Abstract: Hydrothermal pretreatment solubilizes about 65% of the hemicelluloses in sugarcane bagasse. However, nearly 80% of the xylose recovered from the hemicellulosic hydrolysate is present as xylooligosaccharides (XO's), which cannot be directly fermented into pentose (C5) ethanol. In this work a kinetic study of the post hydrolysis process considering the use of three acids – sulfuric, oxalic and maleic – was performed. Xylose and furfural post-hydrolysis profiles showed the reaction time in which xylose peaked with minimum furfural production. Among the three studied acids, sulfuric acid showed the fastest kinetics of post-hydrolysis with XO's being fully hydrolyzed in less than 1 h reaction time. C5 fermentation experiments showed that the detoxified post-hydrolysates fermented with ethanol yields ranging from 0.10 to 0.31 g ethanol g −1 reducing sugars. Most samples were fermented from 48 to 72 h of experiment with productivities ranging from 0.02 to 0.43 g ·L −1 ·h −1 .