Effect of Preheating the Reactants

3 Effect of the reactant preheating temperature on H2 yield (a) and CH4 conversion (b). 

Both CH4 conversion and adiabatic temperature are significantly affected by the 02 CH4 and H20 CH4 feed ratios. The CH4 conversion increases with the 02 CH4 ratio up to the value 0.6, at which total conversion is reached. For values greater than 0.6, the adiabatic temperature continues to increase although the CH4 conversion remains at 100%. This is due to the oxidation reaction of H2 and CO to H2O and CO2 favored by the excess O2 supply. On the other hand, on increasing the H20 CH4 ratio at a fixed 02 CH4 value, the adiabatic temperature decreases. 

In conclusion, thermodynamic analysis can provide the optimal operating conditions to achieve the best ATR performance. It has been found that preheating the reactants promotes H2 production. This effect is more pronounced at higher H20 CH4 ratios and at 02 CH4 molar ratios ranging from 0.1 to 0.7. Employing 

The aim of this section is to demonstrate that the feasibility of a distributed hydrogen system based on methane ATR is the result of a combination between optimized engineering (design and operation) and catalyst (formulation and support structures and geometry). 

A fast-start capability is a key requirement for a compact fuel processor, especially crucial for specific cases such as on-board automotive application. A possible means for the fast start-up of an ATR reactor is starting by feeding to the reactor a mixture with an O2 C molar ratio typical of a rich combustion. The goal of this mode is to raise the reactor temperature quickly and simultaneously avoid catalyst oxidation. Then the reactor will move to the ATR mode through the addition of steam and by decreasing the 02 C feed ratio to the desired value. 

---