Ni/CeO2-ZrO2-a-Al2O3 Systems to obtain synthesis gas

FRANCISCO POMPEO; NORA NICHIO; DELIA GAZZOLI; OSMAR FERRETTI

Natal, Brazil.

Simposio; 8 International Natural Gas Conversion Symposium; 2007

In recent years, the obtention of hydrogen by means of methane, methanol and ethanol reforming has gained importance due to its application as a clean energy source, mainly in fuel cells[1-4]. Most metals of Group VIII have been studied for natural gas steam reforming (SR), partial oxidation of methane (POM), carbon dioxide reforming (DR) and mixed reforming (MR) which uses steam, carbon dioxide and oxygen. Nickel-based catalysts, though very interesting due to their low cost, need to be enhanced to increase their stability and coking resistance.  a-Al2O3 is an adequate support due its high thermal stability and mechanical resistance. The addition of CeO2 and/or ZrO2 aggregates it is known to affect metal dispersion decreasing sintering, to improve thermal stability and oxygen storage capacity.   The purpose of this paper is to study Ni supported catalysts (2 wt %) and to determine the modification effect of a commercial support, a-Al2O3 (BET area 10 m2/g), by adding CeO2 and/or ZrO2 oxides (1 to 5 % of total oxides). POM, DR and MR reactions were studied in an experimental equipment of conventional continuous flow, at atmospheric pressure, in the temperature range 400 - 700 ºC and GHSV= 3.105 ml/h.g. The composition of the feed mixtures was: POM, N2/CH4/O2 = 10/2/1; DR, N2/CH4/CO2 = 6/1/1; MR, N2/CH4/H2O/O2 = 10/2/1/1 (partial pressure of CH4 ~0.15 bar and C/O=1).