Oxidative reforming of ethanol over CeO2-SiO2 based catalysts in a fluidized bed reactor

Abstract

The Pt-Ni/CeO2-SiO2 catalyst, obtained by impregnation of high-surface area SiO2 (400m2g−1) with cerium nitrate hexahydrate and double activated by Nickel and Platinum, was used in the oxidative steam reforming (H2O/C2H5OH=4, O2/C2H5OH=0.5, T=500°C) of ethanol and the performances of packed (PBR) and fluidized bed reactors (FBR) were compared. In the fixed bed reactor, a faster deactivation and lower hydrogen yields with TOS were observed: fluidized bed operation reduced carbon formation rate (CFR) of almost 4 times. The stability of the Pt-Ni/CeO2-SiO2 catalyst was investigated at different operating conditions (WHSV=4.1–20.5h−1) and, independently from contact time, the catalyst, after a partial deactivation, reached a plateau performance with no more variation in ethanol conversion and hydrogen yield. Coke selectivity, in fact, decreases with TOS and the carbon formation rate remained unchanged at steady conditions. The dependence of plateau ethanol conversion and CFR on contact time was also investigated.