3-5-1 Pyrolysis behaviors of Japanese cedar heartwood and sapwood focusing on extractives

Abstract

Wood consists of heartwood and sapwood, and the extractives content of heartwood is higher than sapwood to increase the resistance against the deterioration caused by microorganisms. Such difference may affect the pyrolysis behaviors of the major components (cellulose, hemicellulose and lignin), but this has not been fully clarified. Pyrolysis behaviors of heartwood and sapwood samples were studied using pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS) and thermogravimetric analysis (TGA). The successive extractions with n-hexane, methanol, and acetone/water (70/30, v/v) were also conducted to study the chemical compositions of the extractives and the influences of the removal of extractives on the pyrolytic reactivity of the major components. Extractives were found to accelerate the pyrolysis of major components especially in the heartwood. The majority of the heartwood extractives directly evaporated without suffering from the degradation reactions, while not for those in the sapwood.