Hydrogen, due to its abundance in the universe, is replacing fossil energy sources like coal, oil, etc., which are rapidly depleting. Hydrogen has energy per unit mass of fuel burned, or 120.7 kJ/g compared to any type of fuel (Haryanto et al., 2005). Additionally, fossil sources produce pollutants such as COx, NOx, SOx, CxHx, soot, ash and other organic compounds into the atmosphere when burned, which contributes to global warming. Hydrogen was discovered by Henry Cavendish in 1766 and named in 1783 by Antoine Lavoisier, its name coming from the words "hydro" and "genes" meaning "water" and "generator" because it burns to produce only water ( Song, 2003). It is present in combination with other elements like oxygen in water, carbon in hydrocarbons and must be extracted. Other sources can be various fossil and non-fossil resources such as coal, natural gas, liquefied petroleum gas, diesel, biomass and its derived fuels such as methanol, ethanol and biodiesel (Haryanto et al ., 2005). are used to provide energy for transportation and mobile applications in the form of electricity directly from chemical energy to power laptops, vehicles or other applications where cost is not a big problem like space technology, submarines, etc. They are energy efficient, clean, flexible in terms of fuel, they are not noisy, vibrations are not present and their operation is smooth, which ensures user comfort (Silveira et al., 2009). Additionally, the fuel used in fuel cells has a higher energy density than batteries (Park et al., 2007), which is necessary for portable applications such as laptops, medical and telecommunications devices and for military applications like remote sensors (<20W), silent power generation and battery charging (200W- 2kW) and mobile...... middle of paper ......ry disposal method or adding convective heat). Thus, the ultimate “success” of this technology will largely depend on modeling, understanding and controlling temperature excursions. In this work, ethanol is steam reformed in a non-isothermal tubular reactor which is coupled to ethanol combustion in a recuperative manner where heat is recovered. transferred from the exothermic reaction zone through the channel walls. A complete three-dimensional geometry is modeled, consisting of co-flow and counter-flow configurations. The authors investigated the design configurations based on steam ethanol reforming through one-dimensional models and experiments (Table 2), but a 3D model was needed to fully explore the different transport processes in the configurations and study variations in reactor performance. due to hydrodynamics and heat and mass transfer characteristics.