Identification of volatile degradation products produced during wood mild pyrolysis is important to have better insight on thermodegradation mechanisms. Previous studies have shown that thermodesorption coupled to GC-MS is an attractive tool to characterize and quantify products formed during wood thermodegradation indicating an higher susceptibility of hardwoods to thermodegradation compare to softwoods. The aim of this study is to give better insights on wood thermodegradation pathways during wood heat treatment with special emphasis on the kinetics of thermodegradation. For this purpose, one hardwood species (beech) and one softwood species (Sylver fir) have been subjected to thermal treatment directly in the thermal desorption glass tube of the thermodesorber under helium at temperatures of 210 and 230°C for different times ranging from 10 to 80 minutes and volatiles compounds formed analysed by gas chromatography coupled to mass spectroscopy. Starting from these results, it’s was possible to visualize the different products formed as a function of time allowing determination of the kinetic curves of formation of the main degradation products. Making the assumption that acetic acid is representative of hemicelluloses degradation and vanillin representative of lignin degradation, it was possible using Arrhenius equation to determine a mean activation energy of formation of this two products leading to indirect informations on lignin and hemicelluloses stability for each wood species.

Download document (1.7 Mb)
free for the members of IRG. Available if purchased.

Purchase this document