A stable, novel catalyst improves hydrogen production

JOHN MÚNERA, SILVIA IRUSTA, CARLOS CARRARA, EDUARDO LOMBARDO, LAURA CORNAGLIA

Río de Janeiro, Brasil

Congreso; ENPROMER, (Segundo Congreso de Ingeniería Química y Cuarto de Ingeniería de Procesos del MERCOSUR); 2005

Universidade Federal do Rio de Janeiro y otras

he 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 well known catalyst, Rh/La2O3, together with a novel one, Rh/La2O3-SiO2, in a hydrogen-permeable membrane 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 dispersion (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.