Thermal modification kinetics and chemistry of poplar wood in dry and saturated steam media

This research work presents a modelling strat-egy to analyse thermal conversion rates of two thermalwood modification processes based on time-temperaturesuperposition method. It gathers in a single study differentoriginal and bibliographic experimental works analysingthe dry mass variation that occurs during thermal andhydro-thermal wood modification processes. The mass losskinetic was successfully modelled using a modifiedArrhenius approach. The time-temperature superpositionmethod allowed to define for each wood modificationprocess a master curve and its time shift depending on thetreatment temperature. The analysis of ventilated oven andsaturated steam treatments pointed out the existence of acontinuous single kinetic for the ventilated oven whichbecame more complex for saturated steam since a secondkinetic stage appeared. This kinetic difference was sus-tained by infrared spectra chemical analysis which showedthat hemicelluloses degraded much faster in presence ofsteam while lignin degradation occurred in both conditions.