The literature on biomass pyrolysis regarding kinetics, models (single particle and reactor), and experimental results is reviewed from an engineering point of view. Predictions of existing single particle models derived from a detailed description of the transport phenomena and literature data on measured intrinsic chemical kinetics are presented. The main conclusions from the literature and modeling studies can be summarized as follows: (1) the available knowledge on kinetics and transport phenomena has not been integrated properly for reactor design, (2) complex two-dimensional single particle models do not provide more accurate, or otherwise better, information for engineering calculations than do the simple one-dimensional models, and (3) single particle models predict (for all available kinetics) that the influence of the particle size on the liquid yield is limited. This effect can be explained with the effective pyrolysis temperature, a parameter that represents the particle's average temperature at which the conversion is essentially taking place.