Kinetic and Reaction Engineering Studies of Dry Reforming of Methane over a Ni/La/Al2O3 Catalyst

Kinetic studies of CO 2 reforming of methane over a highly active Ni/La/α-Al 2 O 3 catalyst were performed in an atmospheric microcatalytic fixed-bed reactor. The reaction temperature was varied between 700 and 900 °C, while partial pressures of CO 2 and CH 4 ranged from 16 to 40 kPa. From these measurements kinetic parameters were determined; the activation energy amounted to 90 kJ/mol. The rate of CO 2 reforming was described by applying a Langmuir−Hinshelwood rate equation. The developed kinetics was interpreted with a two-phase model of a fluidized bed. The predictions for a bubbling-bed reactor operated with an undiluted feed (CH 4:CO 2 = 1:1) at 800 °C showed that, on an industrial scale, significantly longer contact times ( H mf = 7.8 m, m cat / V STP = 31.8 g·s·mL - 1 ) are necessary for achieving thermodynamic equilibrium ( X CH 4 = 88.2%, X CO 2 = 93.6%). The performance of the reactor was strongly influenced by the interphase gas exchange: the highest space time yields were obtained for small particles ( d p = 80 μm).