Devolatilization of a single wet wood particle in a hot atmospheric fluidized bed is studied through a mathematical model and experiments. A typical tropical woody biomass, "Casuarina Equisetifolia", is used in the study. A three-dimensional (3D) transient model with detailed consideration of (i) fuel anisotropy, (ii) fuel moisture, (iii) shrinkage during drying and devolatilization, (iv) heat generation, and (v) variable properties with a suitable reaction scheme is developed to determine the devolatilization time (τd) and char yield (Yc) of cubic/cuboidal wood particles at various initial fuel moisture contents and bed temperatures. Experiments are conducted for 10, 15, 20, and 25 mm cube-shaped wood particles at bed temperatures of 1023, 1123, and 1223 K. The model predictions agree well with the measured data (present experiments and those reported in the literature) within ±10% for the devolatilization time and ±11% for the char yield, supporting the validity of the overall structure of the model. A sensitivity analysis is carried out using the 3D model to identify the important parameters influencing the devolatilization time and char yield and the level of confidence (degree of uncertainty) in using them as model inputs. The important parameters considered include the initial wood particle density, thermal conductivity, external surface heat-transfer coefficient, and various kinetic schemes available in the literature. Invariably, the relative influence of the parameters on the devolatilization time and char yield is found to be predominant in larger particle sizes. The initial particle density of wood has the strongest influence on the devolatilization time, followed by the thermal conductivity and specific heat capacity. The devolatilization time increases considerably with an increase in the initial wood density and decreases moderately with an increase in the thermal conductivity of wood, while the char yield remains negligibly influenced by the initial density and thermal conductivity of wood. The devolatilization time decreases considerably when the external surface heat-transfer coefficient is varied from 100 to 500 W m -2 K-1, beyond which the influence is negligible. The prediction of the devolatilization time and char yield is found to be very sensitive to the reaction kinetic parameters (rather than the wood properties), and hence due care must be taken in adopting the right kinetic parameters available in the literature to model. © 2010 American Chemical Society.