Pyrolysis and Combustion Characteristics of Biomass and Waste-Derived Feedstock

The trend for material and energy recovery from wastes along with the need to reduce greenhouse gases has led to an increased interest in the thermal exploitation of biomass and/or wastes. In this work, the pyrolysis and combustion behavior of 10 biomass and waste materials was investigated in a nonisothermal thermogravimetric analyzer (TA Q600) at ambient pressure and 150-250-(mu)m particle size. The effect of the heating rate (5, 20, 50, and 100 °C/min) was also considered. The independent parallel first-order reaction model was elaborated for the kinetic analysis of the pyrolysis results. The thermal degradation of the biomass/waste samples was modeled assuming three or four parallel reactions. At increased heating rates, enhanced pyrolysis rates were achieved. As a result, a slight decrease in total weight loss was observed, accompanied by a systematic increase in pyrolysis starting temperature and an almost linear increase in maximum pyrolysis rate from 5% to 90%/min. Increased combustion reactivity was found for olive kernel and willow, followed by forest residue. The catalytic effect of mineral matter on char oxidation was pronounced in the MBM (meat and bone meal) sample, leading to a reaction rate decrease and shifting the DTG curve to lower temperatures between 300 and 400 °C.