Ni/MgO-Al2O3 and Ni-Mg-O catalyzed SiC foam absorbers for high temperature solar reforming of methane

Ni catalyst supported on MgO-Al2O3 (Ni/MgO-Al2O3) prepared from hydrotalcite, and Ni-Mg-O catalyst are studied in regard to their activity in the CO2 reforming of methane at high temperatures in order to develop a catalytically activated foam receiver absorber for use in solar reforming. First, the activity of their powder catalysts is examined. Ni/MgO-Al2O3 powder catalyst exhibits a remarkable degree of high activity and thermal stability as compared with Ni-Mg-O powder catalyst. Secondly, a new type of catalytically activated ceramic foam absorber - Ni/MgO-Al2O3/SiC - and Ni-Mg-O catalyzed SiC foam absorber are prepared and their activity is evaluated using a laboratory-scale receiver reactor with a transparent quartz window and a sun-simulator. The present Ni-based catalytic absorbers are more cost effective than conventional Rh/gamma-Al2O3 catalyzed alumina and SiC foam absorbers and the alternative Ru/gamma-Al2O3 catalyzed SiC foam absorbers. Ni/MgO-Al2O3 catalyzed SiC foam absorber, in particular, exhibits superior reforming performance that provides results comparable to that of Rh/gamma-Al2O3 catalyzed alumina foam absorber under a high flux condition or at high temperatures above 1000 degrees C. Ni/MgO-Al2O3 catalyzed SiC foam absorber will be desirable for use in solar receiver reactor systems to convert concentrated high solar fluxes to chemical fuels via endothermic natural-gas reforming at high temperatures. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.