The biomass-to-liquid Fischer-Tropsch (FT) process is an industrial process that converts bio-syngas in hydrocarbons ranging from C-1-C-100. Bio-syngas, a syngas mixture produced from biomass, is characterized by a H-2/CO molar ratio in the range 1.0-1.5. An iron-based catalyst supported on silica for CO hydrogenation with 30g/g of metal was prepared, characterized by BET, SEM, TEM, TPR, XRD and tested at different temperatures and H-2/CO ratios in a FT bench scale plant using a Packed Bed Reactor (PBR). The experimental results demonstrated that this catalyst is also suitable for low H-2/CO ratios, since by increasing the inlet H-2/CO ratio, the CO conversion increases, the product selectivity remains largely unchanged, and the catalyst shows a satisfactory stability as a function of time of stream (TOS). Based on the collected data, a rigorous multi-scale simulation of reactor behaviour was developed in order to support the experimental tests and predict the reactor yield and conversion. The elaborated kinetic model is based on the hypothesis that both FT and Water Gas Shift (WGS) reactions are active on the catalyst, and the calculated results agree with the obtained experimental data.