Microwave Drying of Wood Strands

Characteristics of microwave drying of wood strands with different initial moisture contents and geometries were investigated using a commercial 10 small microwave oven under different power inputs. Temperature and moisture changes along with the drying efficiency were examined at different drying scenar ios. Extractives were analyzed using gas chromatography=mass spectrometry (GC=MS). The results showed that the microwave drying process consisted of three distinct periods (warm-up period, evaporation period, and heating-up per- 15 iod) during which the temperature, moisture change, and drying efficiency could vary. Most of the extractives were remnant during microwave drying. It was observed that with proper selections of power input, weight of drying material, and drying time, microwave drying could increase the drying rate, save up to 50 % of energy consumption, and decrease volatile organic compound (VOC) 20 emissions when compared with the conventional drying method.