Fuel grade bioethanol reforming in a fluidized bed reactor over highly durable Pt-Ni/CeO2-SiO2 catalysts

Abstract

In this work, oxidative steam reforming reaction has been investigated in a fluidized bed reactor (FBR) under a fuel grade bioethanol feeding over a 2Pt-10Ni/CeO2-SiO2 catalyst. In a process intensification view, the selection of raw feeds produced from bioethanol paves the way towards a cheaper production of bio-hydrogen. The employed catalyst was prepared by the sequential wet impregnation method and was tested alone as well as in the presence of the bare support as filler of the FBR. Very long durability tests (hundreds of hours) were performed at 500°C under a stream with a water to ethanol ratio of 4 and oxygen to ethanol ratio of 0.5. When the catalyst was tested along with the support, a stable behaviour was recorded for 100 h of time-on-stream (TOS), corresponding to complete ethanol conversion and H2 yield values above 50%. However, for higher TOS, a gradual catalyst deactivation was observed and, after 400 h, hydrogen yield was below 10%. Conversely, the catalyst alone displayed complete conversion form more than 200 hours and, after a partial deactivation, a new stationary condition was reached with no more activity loss. Both the spent catalysts were characterized by several techniques, finding that the presence of the filler promote methane decomposition and coke deposition on catalyst surface. On the other hand, a very low carbon formation rate was recorded over the 2Pt-10Ni/CeO2-SiO2 catalyst, which was shown to be a very promising formulation in comparison with data available in the recent literature.