The adsorption process of HF on wood chips in a packed-bed reactor was studied. Two adsorption rate limiting mechanisms exist for this process, namely HF supply control and intrinsic adsorption control. In the initial period of this process, the adsorption rate is determined by the HF supply rate; after the initial period, the adsorption rate is determined by the intrinsic adsorption rate. Consequently, the HF loading profile for this adsorption process includes two distinct parts : an initial linear part and a following non-linear part, corresponding to the two different rate limiting mechanisms. This conceptual model of HF adsorption in the packed-bed reactor was supported by experimental observations from a bench-scale, packed-bed reactor. Based on this conceptual model, a mathematical model was developed to predict the HF loading for a given adsorption time under given operating conditions. To demonstrate its application, the mathematical model was used to analyze the effect of the heat dissipation rate of the reactor on the adsorption process.