An efficient pretreatment for the selectively hydrothermal conversion of corncob into furfural: The combined mixed bail milling and ultrasonic pretreatments

摘要

A mixed ball milling of corncob and the solid acid catalyst (SO42-/SiO2-Al2O3/La3+) followed by the ultrasonic pretreatment has been developed for the selectively catalytic hydrothermal conversion of corncob into furfural. Results showed that the combined mixed ball milling and ultrasonic pretreatment (MU) was an efficient mechariocatalytical approach to destroy the complex structure of corncob, and most of the hemicelluloses could be released from the corncob cell wall during the subsequent hydrothermal reaction. In comparison with the ultrasonic pretreatment, ball milling played a more important role in the deconstruction of corncob and the depolymerization of polysaccharides. The existence of the solid acid catalysts (SO42-/SiO2-Al2O3/La3+) during the ball milling and ultrasonic pretreatments had the significant influences on the successful conversion of corncob into furfural due to the solid-solid reaction of the solid acids and the dewaxed corncob during the pretreatment process, which was in favor of the furfural production. A highest furfural yield of 197.76 mg/g could be obtained at 190 degrees C for 30 min from the MU-pretreated corncob. (C) 2016 Elsevier B.V. All rights reserved.