Kinetic studies and predictions for xylo-oligosaccharide production by acidic hydrolysis of xylan with various acids

• Kinetic models of xylan degradation process with various acids were established. • Activation energy analysis confirmed that organic acids are preferable for XOS. • XOS with yield of 47.2% can be achieved from xylan by lactic acid hydrolysis. Acidic hydrolysis of xylan for xylooligosaccharide production has already been intensively investigated allowing for its high efficiency and simple manufacturing procedure. For the purpose of gaining insight into the relationship between the degradation process of xylan and yields of xylooligosaccharides, in this study, four acids (sulfuric, maleic, lactic and acetic) with different pKa values were employed to hydrolyze xylan and different kinetic models were established by further analyzing the hydrolysis process from the perspective of reaction rate and activation energy. All results confirmed that weaker organic acids were more suitable for the production of xylooligosaccharides, providing a higher generation rate of xylooligosaccharides and a lower xylose formation rate. A xylooligosaccharides’ yield of 47.2% could be achieved by lactic acid hydrolysis based on prediction of kinetic models. This study provides a convenient and convincing method for the selection of acid catalysts on xylooligosaccharides production from xylan.