Biomass gasification process is simulated in order to determine the influence of the operating parameters on the quality of the gas produced. Furthermore, the hydrogen required to enrich the syngas is also established. The modeling and simulation showed that the gas obtained by gasification at atmospheric pressure is mainly composed of H2 and CO; however, the molar ratio H2/CO is not favorable for synthesizing fuels such as methanol. This shows the need to enrich the syngas with additional hydrogen. For the case study developed, for each 100 kg / hr of biomass waste gasified, the amount of additional hydrogen required ranges between 2 to 6 kg / hr in order to obtain a molar ratio H2/CO close to 2. Using palm fiber, the amount of hydrogen required would be 4 kg / hr. This additional hydrogen could be derived from solar energy using thermoelectric modules with an effective area of solar radiation close to 400 m2 per kg of biomass. The simulation was performed using ASPEN PLUS®.