Abstract
Biomass, as a renewable resource, has attracted much attention due to its abundant reserves and wide range of applications. In this study, three different biomass feedstocks, eucalyptus wood powder, rice bran and bagasse, were selected, and their structural and morphological evolutions and resistivity changes were analyzed in detail under three pyrolysis conditions, namely, 500℃, 700, ℃ and 900℃. The results showed that with the increase of pyrolysis temperature, the number of microporous structures of biomass charcoal firstly increased and then collapsed and blocked, and some functional groups on the surface weakened and decreased with the increase of pyrolysis temperature, all of which formed stable aromatic compounds with C = C and C = O as the main structures. From the XRD and Raman spectroscopy analysis, It can be seen that the degree of graphitization of biochar increases gradually with the rise of pyrolysis temperature, and the ball milling treatment to a certain extent can change the crystal structure of the charcoal material. meanwhile, the resistivity of the biochar material decreases gradually with the increase of pyrolysis temperature. 900℃pyrolysis of the eucalyptus biochar could reach a resistivity of 0.0196 Ω/cm at 27.3 MPa, which is much better than that of the biochar prepared at low temperature, and the smaller particle size can be obtained under the same ball milling conditions. The current research provides a guidance to facile method to prepare biochar and sustainable utilization of biomass.