Thermal decomposition of surrogate wastes

Results on the thermal behavior characteristics during the decomposition of cellulose and cellulose-polystyrene mixtures in a controlled environment are presented. Thermogravimetry analysis (TGA) tests were conducted on the decomposition of cellulose and mixtures of cellulose-polystyrene (100% cellulose, 90% cellulose-10% polystyrene and 50% cellulose-50% polystyrene) in nitrogen and air environments. These tests were performed at a heating rate of 50°C/min. The TGA tests were followed by addition of air at the end of the thermal decomposition process to further destruct the residual char remaining from the material. Differential scanning calorimetry (DSC) was also used to measure the heat flow into the sample during pyrolysis (endothermicity) and during combustion of the solid residue (exothermicity). The TGA results provided mass evolution of the samples versus temperature while the DSC data provided heat flow into and out of the sample during the process of pyrolysis and combustion. TGA results also showed that all samples contained moisture in addition to the fixed carbon. The temperature dependency and mass loss characteristics of the materials were obtained. This information was used to obtain Arrhenius kinetic parameters and therefore the overall decomposition rates under defined conditions of pressure, temperature, surrounding chemical environment, heating rate of the material, and material´s chemical composition. The thermal decomposition of these materials can be related to their chemical composition