A simple method is proposed for the estimation of the effective lateral dispersion of fuel in a fluidized-bed combustor. The method is based on a combination of a model for drying and devolatilization of the fuel and cross-sectional measurements of the water concentration above the bottom bed during steady-state operation. By correlation of the drying of the fuel particles and the measured moisture concentrations above the bed, the effective lateral dispersion coefficient of the fuel particles is determined. This coefficient was estimated to be on the order of 0.1 m(2)/s, which is considerably higher than that predicted by most of the expressions given in the literature.