Catalytic partial oxidation of methane on rhodium and platinum: Spatial profiles at elevated pressure

Abstract

Under pressure : Spatially resolved species and temperature profiles inside foam monoliths have been investigated. This has been done under catalytic partial oxidation conditions of methane over Rh- and Pt-coated catalysts at pressures up to 1.1 MPa. Our results show that the Rh catalyst is governed by mass transfer limitations, while the Pt is kinetically controlled. Catalytic partial oxidation (CPO) of methane is a potential technology for conversion of methane into synthesis gas, because the process operates autothermally with millisecond residence times and at high temperatures ( > 800 ° C) with no external heating. In an industrial setting, it is required to operate the process at elevated pressure. In this work we present spatially resolved data on the effect of pressure on CPO of methane on Rh- and Pt-coated foams from 0.1 to 1.1 MPa total pressure. There is little effect of pressure over Rh on rate at constant mass flow rate, which can be explained by mass transfer limitations. At constant linear inlet velocity the oxidation zone is extended with increasing pressure, again in accordance with mass transfer limitations. On Pt increasing pressure at constant mass flow rate leads to faster oxygen consumption and higher H 2 production because of higher operating temperature and longer residence times. Catalyst deactivation was not observed for Rh, but initial deactivation was observed for Pt.