Microwave-Assisted Per Acetic Acid to Pretreat Beech Biomass for Subsequent Thermal Conversion

Abstract

Microwave-assisted per acetic acid (PAA, 15% v/v) pretreatment effectively destroyed the structure of beech wood, and increased its cellulose crystallinity. The FTIR peaks originated from lignin decreased or disappeared, indicating that the pretreatment was effective at removing lignin. According to the TG analysis, the peak of hemicellulose disappeared for the pretreated biomass, indicating the removal of hemicellulose by the microwave-assisted pretreatment. Besides, the char yield of pretreated beech wood was only 10.1 %, which was much lower than raw beech wood. Therefore, the pretreatment can decrease catalyst deactivation by coke deposition, which a major obstacle for thermal conversion.