Abstract

The objective of this study was to investigate the carbonization induced by microwave treatment (MWT) of spruce (Picea sp.) wood, which was treated in a domestic microwave oven at 2.45 GHz. Structural changes were observed by elemental analysis, thermal analysis, and by IR and Raman spectroscopy. The degradation of the samples was completed within 3 min. The carbonization was comparable to that caused by heat treatment at ca. 420°C. In the MWT samples, a graphitic layer was not detected, which behaves as a sensitizer for MW irradiation and sometime elevates the temperature drastically. This study shows that MWT leads to a carbonaceous material, and that the carbonization levels off with the loss of heat-inducing functional groups, such as O-H, CO-OH, C=O, upon MW irradiation. MWT is better suited as a kind of controlled and short pretreatment method before carbonization. Its suitability for porous absorbents should be investigated.