Recently, the synthetic natural gas (SNG) has been available for large consumers in the Brazilian domestic market. The SNG is a suitable fuel with potential use to several processes and facilities of the steel industry. This paper investigates the injection of SNG into charcoal blast furnaces as a substitute for granular charcoal charged from the top and pulverized charcoal injections with potential increase of productivity and decrease of specific CO₂ emissions. In order to study the effect of replacement of granular charcoal and injection of pulverized charcoal the well known Blast Furnace Five Fluid Model (BF-FFM) is applied to describe detailed phenomena within the process. This model treats the blast furnace as a five-phase reactor, accounting for gas, lump solids (raw iron ore, sinter, pellets and granular charcoal), hot metal, pulverized charcoal, and molten slag. The model is based on conservation equations for mass, momentum, energy and chemical species numerically solved based on the finite volume method (FVM). The SNG has high amount of H₂ and strongly affects the inner conditions of the reactor and only a comprehensive model with detailed chemical reaction rates can properly predict the inner parameters of the process and hence furnish useful information to design smooth operational conditions. The simulation results obtained in this study indicated that smooth operations using SNG up to 25 N m³/t of pig iron could be achieved simultaneously by increasing the productivity up to 58% and with a decrease of 40 kg/thm on the granular charcoal charged.