Synthesis Gas Production from Methane with SrFeCo_0.5O<i>_y</i> Membrane Reactor

Abstract

Partial oxidation of methane to synthesis gas was investigated in a reactor consisting of an oxygen-permeable SrFeCo0.5Oy membrane tube and a Ni/γ-Al2O3 catalyst bed located after the membrane tube. In this reactor, part of methane reacted with oxygen that permeated through the membrane from air, and the resultants (H2O, CO2) and the rest of methane were transported to the catalyst bed where they were converted to syngas. When a reactor of membrane surface area 4.6 cm2 was run at 900 °C with a methane feeding rate of 26.8 mL/min, the throughput conversion of methane was ∼98%, the CO selectivity ∼98%, H2/CO ∼1.8, syngas generation rate 16 mL/min/cm2. Under the reactor conditions, the layered phase Sr4(Fe,Co)6O13 in the membrane gradually decomposed to a perovskite phase SrFe1-xCoxO3-δ with high oxygen permeability and spinel phase [(CoFe)]2CoO4 with catalytic activity toward the oxidation of methane. The Ni-based reforming catalyst exhibited desirable activity and stability in the membrane reactor, which may be attributed to the absence of the “hot spots” in the catalyst.