A promising copper based oxygen carrier produced using industriallyrelevant manufacturing equipment has been aged in IFPEN's 10 kW th Chemical Looping Combustion pilot plant. Methane combustion was performed at 900°C for 160h with an OC/fuel ratio of 1.2. While full methane conversion to CO 2 and water was achieved in the early stage of the experiment, fast deactivation was observed. The oxygen carrying particles were thoroughly characterized at various stages of the ageing experiment, from which a pathway leading to deactivation is proposed.
Direct evidence for cobalt oxidation under water treatment at 230 °C was revealed using in situ XRD, even in the presence of small amounts of H2. Oxidation kinetics was proved to be particle size dependent. The resulting Co3O4 showed a firmly smaller coherent domain size than the initial calcined catalyst.
The adsorption properties of several branched paraffins from C4 to C6 on MFI type zeolite were investigated.
A temperature-programmed-equilibration method was used for this study, and the analysis of the desorption
rates as a function of temperature showed two desorption peaks. The interpretation of this phenomenon
is discussed, and it is revealed that the high-temperature desorption occurs in conditions close to equilibrium
while low-temperature desorption is subject to diffusional limitations. Furthermore, an XRD study shows
that the phase transition in the crystal structure can be lowered by 70 K when 3-methylpentane is adsorbed.
This property shows that the low-temperature desorption peak is not due to a change of symmetry in the
structure of the zeolite. Modeling of the high-temperature peak provided adsorption isosteric enthalpy and
entropy variations. These values are consistent with literature data. For the first time, adsorption isosteric
entropy variations of sorption are calculated for branched alkanes in silicalite-1.
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