Effect of Torrefaction on the Properties of Corn Stalk to Enhance Solid Fuel Qualities

This study presents the effects of torrefaction on the basic characteristics of corn stalks. Corn stalks were torrefied in a horizontal tubular reactor at temperatures ranging from 150 °C to 400 °C, for torrefaction periods varying from 0 min to 50 min. The torrefied corn stalk products were characterized in terms of their elemental composition, energy yield, ash content, and volatile fraction. The gaseous products were also analyzed. Thermogravimetric analysis (TGA) of the samples was carried out in order to obtain the apparent activation energy for the torrefaction of corn stalks. The weight loss data according to the degradation temperature were analyzed using three different methods. The energy and mass yield were found to decrease with an increase in the temperature, whereas the higher heating value (HHV) increased. From this work, it was found that the compounds with oxygen were emitted at a temperature lower than that for hydrocarbon gases and the temperatures of 290–330 °C were the optimum torrefaction temperatures for corn stalks.