A STABLE, NOVEL CATALYST IMPROVES HYDROGEN PRODUCTION

S. IRUSTA, J.MÚNERA, C. CARRARA, E.A. LOMBARDO, L.M. CORNAGLIA

Rio Janeiro - Brasil

Congreso; EMPROMER: 2nd MERCOSUR CONGRESS ON CHEMICAL ENGINEERING; 2005

The membrane reactors employed for the dry reforming reaction were based on different membrane types. This reaction taken as a source of H2, was performed in the present work using a wellknown catalyst, Rh/La2O3, together with a novel one, Rh/La2O3-SiO2, in a hydrogen-permeable membrana reactor. The catalysts were characterized by DRX, TPR, FTIR, LRS, H2 and CO chemisorption. The effect of the operation variables upon the performance of the membrane reactor was also studied. The novel Rh(0.6%)/La2O3(27%)-SiO2 catalyst proved to be the best formulation. Operating at 823 K, both methane and CO2 conversions were 40% higher than the equilibrium values, producing 0.5 mol H2/mol CH4. This catalyst, tested at W/F three times lower than the Rh(0.6%)/La2O3, showed a similar performance. In all cases, the activity of the Rh catalysts remained constant after 100 hours on stream at 823 K. The presence of tiny amounts of graphite only detectable through LRS did not endanger membrane stability. The incorporation of the promoter (La2O3) to the silica support induced a parallel increase in the metal dispersión (CO adsorption). The concentration of surface Rh atoms slightly increased with lanthanum addition. The better performance of Rh(0.6%)/La2O3(27%)-SiO2 was related to the high dispersion and reaction rate of this formulation.