Characterisation and model fitting kinetic analysis of coal/biomass co-combustion

• Co-combustion characters of biomass, anthracite and their blends were studied.
• The new model considering double parallel reactions in combustion was built up.
• Biomass can improve the combustion characteristic of anthracite.
• Reasonable utilization of biomass in industrial production is important.

The combustion behaviors of biomass, coal and their blends were studied by thermogravimetric analysis. Combustion parameters such as ignition, burnout, peak rate, ignition index, and combustibility index were analyzed. The kinetic parameters were optimized based on experimental results by a double parallel reactions random pore model (DRPM) proposed in this paper. The results show that the combustion characteristic temperature of the biomass is lower and maximum rate of combustion is higher than that of anthracite coal. With the increase of biomass content, ignition temperature and burnout temperature of blends tended to decrease, while the ignition index and combustibility index increased. Compared with the original RPM model, the DRPM model could not only describe the combustion process with a single peak rate, but also the combustion of biomass-coal blends with two rate peaks. The combustion activation energies of blends were extracted by DRPM model in the present study.