Thermal degradation of Pinus halepensis pine-needles using various analytical methods

The analytical methods of DSC, TG, DI-MS, Py-GC-FID, Py-GC-MSD were used to study the thermal degradation of Pinus halepensis pine-needles. As was shown by DSC measurements endotherm peaks could be attributed to the desorption of high volatility compounds, moisture, softening and/or melting of the waxy constituents of pine-needles; as well as to the degradation of hemicellulose and cellulose. Exotherm peaks could be attributed to the pyrolysis of lignin and char recombination. These results were reconfirmed by DTG curve. In addition, the DI-MS measurements showed, through the presence of certain mass peaks, the existence of volatile degradation products which can be related to the degradation pathways observed by DSC and TG. Py-GC-FID proved that the evolution of organic degradation products commences at 200-250 degrees C and has its maximum evolution rate between 350 and 450 degrees C. Py-GC-MSD analysis of the flash pyrolysis products at 400 degrees C identified a number of organic compounds and CO2. (C) 1997 Elsevier Science B.V.