Heat transfer and thermodynamic analysis of synthesis gas
production processes in chemical reactors with integrated heat
exchangers by steam reforming
Heat transfer and thermodynamic analysis are performed using computational fluid dynamics and chemical kinetics to investigate the synthesis gas production processes in chemical reactors with integrated heat exchangers by steam reforming. The change of thermal energy in the reactor is fully described in order to analyze the influences of fluid velocity, solid thermal properties, and flow arrangement on the thermal behavior of the reactor. The evolution of energy is discussed in terms of reaction heat flux, and thermodynamic analysis of the oxidation and reforming processes is performed in terms of enthalpy changes. The results indicate that while the net sensible enthalpy change is always positive in the reactor, the net enthalpy change for the endothermic and exothermic reactions is positive and negative, respectively. The wall thermal conductivity plays a significant role in determining the efficiency and operation of the autothermal system. The parallel flow design is advantageous for purposes of avoiding localized hot spots and enhancing heat transfer. The change in enthalpy is vital to the endothermic and exothermic reactions. The thermal behavior of the reactor system depends upon the thermal properties of the walls. The change in flow arrangement significantly affects the reaction heat flux in the reactor. The endothermic reforming reaction can proceed efficiently and rapidly if the wall thermal conductivity is high. The reaction heat flux for the endothermic and exothermic processes is negative and positive, respectively. The wall heat conduction effect accompanying temperature changes is of great importance to the autothermal design and self-sustaining operation of the reactor.
Keywords: Hydrogen; Steam; Carbon; Methanol; Air; Copper