Kinetic Studies on Thermal Degradation of Nonwood Plants
Keywords:Bagasse, rice straw, rice hulls, pyrolysis, combustion, TGA, DTA
AbstractThermal analysis of nonwood plants (bagasse, rice straw, and rice hulls) was carried by using differential thermal (DT) and thermogravimetric (TG) analysis under oxidizing and inert atmospheres. Degradation patterns were different, depending on the kind of material and on the pyrolytic atmosphere. Thermal curves of rice straw and hulls were very similar, but bagasse showed a different curve. Degradation of bagasse is similar to hardwood. The rate of thermal degradation of nonwood plants is faster than wood because of their porous structure. Kinetic studies were based on weight loss obtained from TG analysis. A dual mechanism concept, similar to wood, was found for nonwood plants. Two values of activation energy were obtained with a transition temperature at 335 C. Rice straw and hulls have low values of activation energy due to their porous structure and presence of high percentage of silica, while activation energies of bagasse are close to that of hardwood. The presence of inorganic impurities in the cellulosic material has an effect on the kinetics of thermal decomposition.
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