Influence of pre-treatment on torrefaction of Phyllostachys edulis

This study investigated the effects of different pre-treatments on structural changes in Phyllostachys edulis. Samples were pretreated with water, 15% ammonia water, 2% sulfuric acid, hydrothermal carbonization, and ball milling. Moreover, ultrasound was introduced. The influence of pre-treatment on the physiochemical property and composition of P. edulis were studied. Moreover, torrefaction characterization was performed and the distribution of torrefaction products of pretreated samples was determined. Results showed that pre-treatment effectively modified physiochemical structure and the torrefaction property of P. edulis. The pretreatment reduced the ash content and increased the bio-oil content of the torrefaction products. Compared with that of the raw material, the residual bio-char content of the pretreated samples decreased by 2-8%, and degradation temperature of bio-char fluctuated between 365°C and 321°C. The distribution of bio-oil contents, bio-char, and bio-gas in the torrefaction products significantly varied with pretreatments methods.