Experimental Determination of Moisture Diffusivity of Birch

Birch is one of the renewable biomass resources. The high moisture content of raw materials increases the cost of transportation and pelletization. Drying is an effective approach to reduce the moisture content of biomass before storage and other operations to a safe and manageable level. Moisture diffusion in wood could affect the drying process significantly. In this study, the drying process of Birch materials was modeled by Fick's second law. Results from the experiment were utilized to determine the moisture diffusivity with parameter estimation. It showed that the diffusion coefficients of Birch increased from 1.2 x10(-7)to 9.6 x10(-7) m(2) h(-1) with the temperature ranging of 20-60 degrees C. The trend of moisture diffusion coefficients followed Arrhenius equation with respect to temperature. For high-temperature drying, this model can help to terminate the drying process in a timely manner, thus conserving energy consumption.