Production of xylo-sugars from corncob by oxalic acid-assisted ball milling and microwave-induced hydrothermal treatments

A feasible approach for the production of xylose and xylooligomer from corncob was developed using oxalic acid-assisted ball milling, followed by the microwave-induced hydrothermal treatment. Parameters such as milling time, the amount of oxalic acid, hydrothermal treatment time and temperature were evaluated. Results showed that most of hemicelluloses in the cell wall could be released and degraded into xylose and xylooligomer after ball milling for 60 min in the presence of trace oxalic acid and then treated by the hydrothermal treatment under microwave. The maximum yield of xylo-sugars (xylose and xylooligomer) was 86.10% under the ball milling pretreatment of corncob for 60 min with 15-mM oxalic acid and followed by the hydrothermal treatment at 130 degrees C for 30 min. Under this optimal treatment condition given, the production of by-products such as acetic acid and furfural was limited. (C) 2015 Elsevier B.V. All rights reserved.