Simulation study of the effect of feed moisture on autothermal reforming in short contact time catalytic micro channels

• A 1D-model was associated with the detailed gas and surface reaction mechanisms.
• Sensitivity of CH4 conversion and syngas yield to feed moisture was investigated.
• For a wet feed, syngas production is more suitable at small pores and low pressures.
• In a “fuel rich feed”, feed moisture can effectively enhance the syngas yield.
• In a “fuel lean feed”, H2 and CO selectivities are more sensitive to feed moisture.

In this work, a set of cylindrical rhodium coated micro channels with diameter range of 0.2–0.8 mm and a length of 1 cm is considered to simulate the behavior of the autothermal reforming reactions of methane to synthesis gas. A one-dimensional heterogeneous model is used to describe the flow field. Gas phase reactions are modeled by GRI 3.0 mechanism, and a 38-step detailed surface mechanism over a rhodium catalyst is considered for catalytic reactions. The effect of feed moisture content on product selectivity and yield, minimum required preheat temperature, length of the reforming and oxidation zones, and reactor thermal efficiency is studied at two different operating pressures of 1 and 20 atm, methane to oxygen feed ratios of 1.2–2.5, and pore diameters of 0.2–0.8 mm. Moreover, the simulation results are compared with the experimental data of Michael et al. [13].