Syngas production from chemical-looping steam methane reforming: The effect of channel geometry on BaCoO3/CeO2 monolithic oxygen carriers

Abstract

Chemical-looping steam methane reforming (CL-SMR) is a promising technology to achieve the co-production of syngas and hydrogen. The performance of oxygen carriers in the partial oxidation of methane stage is crucial for the composition of syngas products. In this study, the performance of BaCoO3/CeO2 monolithic oxygen carrier for syngas production was investigated. The result of characterizations suggested that the oxygen carriers maintain the ideal crystal structures, the macroporous layer of BaCoO3/CeO2 adhered to monolith achieved a good energy supply and a high gas-solid contact area. To determine the reaction heat of partial oxidation of methane, the standard enthalpy of formation of BaCoO3 was measured by DSC, the obtained value was −957.794 kJ/mol. Based on the experimental result, a kinetic model of partial oxidation of methane was established, the obtained value of A and Ea were 75.902 and 74.772 kJ/mol, respectively. The effect of geometry on reaction performance was investigated by numerical simulation. It suggested increasing number of channel faces could improve the uniformity of reaction, the uniform reaction along the channel was beneficial to control the extent of reaction. Monolithic oxygen carriers need a proper geometry design to find a compromise between the heat storage for temperature control and reaction surface area.