Combustion characteristics of Turkish hazelnut shell biomass, lignite coal, and their respective blends via thermogravimetric analysis

Thermal behavior and combustion kinetic of coal, hazelnut shell, and coal/hazelnut shell blends at the proper ratio were investigated with thermogravimetric analysis (TG). Four mass ratios (20, 30, 40, 50 mass%) of coal/biomass blends were prepared and oxidized under dynamic conditions from temperature 298 to 1,173 K at different heating rates. TG analysis indicated that the combustion of blended samples divided into two stages namely devolatilization and char oxidation combined with coal combustion step. The influence of biomass blends on thermal and kinetic behavior of coal was studied under non-isothermal conditions. It was found that the thermal degradation temperature of coal was higher than that of blended samples due to the molecular structure strength. Ozawa-Flynn-Wall model was applied to deal with non-isothermal TG data for the evaluation of the activation energy corresponding to the combustions of coal, hazelnut shell, and coal/hazelnut shell blends. The average activation energy changed in the range of 90.9-215.3 kJ mol(-1), respectively, depending on blending ratio.