Premium
Two‐stage dilute acid‐catalyzed hydrolytic conversion of softwood sawdust into sugars fermentable by ethanologenic microorganisms
Author(s) -
Kim Kyoung Heon
Publication year - 2005
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2268
Subject(s) - sawdust , chemistry , xylose , hydrolysate , hydrolysis , softwood , pentose , sulfuric acid , hemicellulose , fermentation , food science , raw material , organic chemistry , pulp and paper industry , engineering
Abstract Softwood hemlock residues generated in a sawmill were tested as a feasible agricultural feedstock for the production of high‐value bio‐based products using the concept of two‐stage dilute acid hydrolysis. To convert the carbohydrate contained in the hemlock sawdust, two‐stage dilute‐acid catalyzed hydrolysis was conducted. In the first stage, sawdust was hydrolyzed at 190 °C for 150 s with 1.1wt% sulfuric acid and 46.0 wt% total solids. As a result, 69.3% mannose, 74.2% galactose, 67.7% xylose, and 17.4% glucose of their theoretical maximum yields were achieved, which reveals that hemicellulose was the major target in the first‐stage hydrolysis. After recovering soluble sugars by washing from the first‐stage hydrolysate with water, the washed first‐stage hydrolysate solids were hydrolyzed again in the second stage at more severe conditions, such as 2.6 or 3.5 wt% H 2 SO 4 , 205 or 210 °C, and 80–135 s. After the two stages, the highest overall yields from 100 g of dry hemlock sawdust were a total of 39.3 g of fermentable sugars (36.0 and 3.3 g of hexose and pentose sugars, respectively). These results indicate that hemlock sawdust could be used to produce fermentable sugars which can be converted into other value‐added bio‐based products. Copyright © 2005 Society of Chemical Industry