Kinetics for Steam and CO2 Reforming of Methane Over Ni/La/Al2O3 Catalyst

Abstract

Kinetic studies of mixed (steam and dry) reforming of methane on Ni/La/Al2O3 and Ni/La-Co (1, 3 wt%)/Al2O3 catalysts were performed in an atmospheric fixed-bed reactor. Kinetie parameters for the mixed reforming over these catalysts were obtained under reaction conditions free from heat and mass transfer limitations. Variables for the mixed reforming were the reaction temperature and partial pressure of reactants. The fitting of the experimental data for the rate of methane conversion, r(CH4), using the power law rate equation r(CH4) = k(Pr-CH4)(alpha)(P-CO2)(beta)(P-H2O)(gamma) showed that the reaction orders alpha, beta, and gamma are steady and obtained values equal to alpha (sic) 1, beta (sic) 0, and gamma (sic) 0. In other words, among CH4, CO2, H2O, and H-2, only CH4 reaction orders were not zero and they were affected by the promoters. The apparent activation energy on catalysts Ni/La/Al2O3, Ni/La-Co (1)/Al2O3 and Ni/La-Co (3)/Al2O3 is 85.2, 93.8, and 99.4 kJ/mol, respectively. The addition of Co to Ni/La/Al2O3 was increased the apparent activation energy of the mixed reforming reaction. And the Ni/La-Co (3 wt%)/Al2O3 catalyst showed the highest reforming activity and apparent activation energy. The Co promoters can increase the apparent activation energy of mixed reforming of methane.