Study of Combustion Property of Biomass Char/Coal Char Blended Char Based on Isothermal Thermo-Gravimetry in O2/N2 Atmospheres

Kinetics of biomass char (BC)/coal char (CC) blends at five mass ratios in 30%O2-70% N2 atmosphere were studied using the isothermal thermo-gravimetric method. The combustion reaction process was simulated by using random pore model (RPM), unreacted core model (URCM) and volumetric model (VM). The results show that the combustion property of the blended char was in relationship with the biomass char blending ratio and the isothermal combustion temperature. When increasing the biomass char (BC) share and the combustion temperature, the combustion rate can be increased apparently with more less time. It can also be described by the kinetics calculation that the RPM model is the optimized model to represent the combustion process. For each biomass char (BC)/coal char (CC) ratio in the mixture, the activation energy and pre-exponential factor were determined using the Arrhenius equation.