The purpose of this study was to apply the sewage sludge from the wastewater treatment plant from Fideicomiso del Alto Río Blanco, Veracruz (FIRIOB). Physicochemical and microbiological characteristics were determined of the sludge, elemental analysis (C, H, O, N and S) heavy metal content. The Lower Heating Value (LHV) and the High Heating Value (HHV) were determined for evaluation as an energy source, thermogravimetry and differential scanning calorimetry to determine the behavior of the sludge when subjected to different temperatures. Data generated in the characterization of sludge were used in the simulation and this was carried out by Aspen Plus. Cold gas efficiency (η _CGE) of 88.79% was obtained by gasifying with oxygen in contrast to the 71.9% η _CGE by gasifying with air. Costs are reduced in sludge drying process to gasify with a content of 30% humidity with air and 10% humidity with oxygen. According to the characteristics of sludge and simulation results, it was concluded that the sludge from the wastewater treatment plant are suitable for use as a source of alternative energy.