Experimental Determination and Modeling of Drying Process of Woody Biomass

Abstract

Birch is a kind of readily available woody biomass resource, which can be used to crush and manufacture fuel particles and animal bedding. One of the important aspects during the production system is the drying of biomass prior to storage or processing. Moisture migration in wood is a particularly important factor in determining the drying process. The objectives of this study are to investigate the drying characteristics of Birch and develop a model to simulate moisture diffusion in Birch during the drying process. Experiments were conducted in a controlled environment chamber. Different temperatures and relative humidity were set to simulate the different drying conditions. The mechanism of moisture movement in Birch samples during the drying process was represented by a diffusion model according to Fick's second law. A computer program in Matlab software was developed to simulate the infinite element model. Moisture diffusivity of Birch was determined by minimising the sum of squares of the residuals between experimental results and numerically predicted data. Results showed that the moisture diffusion coefficients of Birch ranged from 1.2×10-7m2/hr to 9.6×10-7m2/hr with temperature varying from 20°C to 60°C. And the trend of diffusion coefficient versus temperature was in accordance with the Arrhenius equation.