Among the renewable energies available, biomass constitutes an auspicious option, due to its environmental-friendly character allied to its significant energy supply. As a path to maximize biomass energy efficiency, gasification has been reported as an adequate technology. Numerical models that can predict and optimize the experimental conditions as well as the equipment design for biomass gasification are imperative, towards a cost-saving and sustainable performance. This work shows the experimental and numerical results of thermal gasification of Portuguese peach stone. Assays were performed using a thermal gasification pilot plant with a bubbling fluidized bed at temperatures ranging from 750 degrees C to 850 degrees C with mass flow rates of 30 kg/h to 60 kg/h. A homemade comprehensive two-dimensional CFD model is proposed to optimize the operating conditions of the biomass gasification process. The numerical model results were compared with experimental data and good agreement was found. A parametric study was performed in order to understand the influence of moisture content, steam to biomass ratio and equivalence ratio in the composition of the producer gas. The results of the study showed a negative impact of moisture and equivalence ratio over conversion efficiency and producer gas quality, and a positive impact for steam to biomass ratio which promotes higher calorific values and overall efficiency for the process. (C) 2017 Elsevier Ltd. All rights reserved.