Thermal degradation of cereal straws in air and nitrogen

Abstract

The termogravimetric behavior of four cereal straws (wheat, barley, oats, and rye) was examined at three heating rates (10, 20, and 50°C/min) in air and nitrogen atmospheres. The thermal degradation rate in active and passive pyrolysis zones, the initial degradation temperature, and the residual weight at 600 °C were determined for these straws in both atmospheres. Increasing the heating rate increased the thermal degradation rate, and decreased both the initial degradation temperature and the residual weight at 600 °C. The higher the cellulosic content of the straw, the higher the thermal degradation rate and the initial degradation temperature. Also, higher ash content in the straw resulted in higher residual weight at 600 °C. The thermal degradation rate in active pyrolysis zone was lower in air atmosphere than in nitrogen atmosphere, whereas the thermal degradation rate in passive pyrolysis zone and the residual weight at 600 °C were higher in nitrogen atmosphere than in air atmosphere.