Thermogravimetric analysis and pyrolytic kinetic study on coal/biomass blends

Three biomass and one lignite were co-pyrolyzed in a thermogravimetric analyzer to investigate the pyrolysis performance of each material, as well as their mixtures. The lignite was blended with biomass at the percentage of 10%, 20%, 35% and 50% respectively. The results show that the initial volatile releasing temperature and the first maximum peak temperature of co-pyrolysis increase with increasing amount of lignite in blends. The position of the second maximum peak is shifted to lower temperature as the percentage of biomass is raised. Co-pyrolysis of coal/biomass blends produces more char than the summation of individual lignite and biomass pyrolysis. The pyrolysis of demineralization and devolatilization rice straw show that the alkali and alkaline earth metals promote pyrolysis of the blends at lower temperature, while Si inhibits the pyrolysis rate. Both volatile and mineral matter in biomass interact with lignite in co-pyrolysis. The synergistic effects in the copyrolysis of biomass and coal are suggested.