Influence of the Methane Combustion Kinetic Model on the Operating Conditions of an Autothermal Catalytic Reactor

LOPEZ, EDUARDO; SCHBIB, SUSANA; GIGOLA, CARLOS; BUCALA, VERONICA

INDUSTRIAL & ENGINEERING CHEMICAL RESEARCH

AMER CHEMICAL SOC

Lugar: Washington; Año: 2001 vol. 40 p. 5199 - 5205

0888-5885

This work focuses on the study of the influence of the methane combustion kinetics on the operation of an autothermal catalytic reactor for heat generation (domestic scale). The feed (methane and air) is preheated by means of a direct heat exchange by recycling a fraction of the hot gases leaving the catalytic combustor (recycle monolithic reactor). Two kinetic models are proposed to represent the reaction. The kinetic parameters were adjusted using experimental data obtained from methane combustion over a laboratory catalyst (Pd on γ-Al2O3 wash-coated cordierite monolith). Experiments were carried out for different feed temperatures (310-500 °C), total flow rates [250-750 cm3/min (STP)], and inlet methane concentrations (0.8-1.6%). A heterogeneous unidimensional steady-state model was employed to analyze the autothermal reactor performance. Using the best-fitted reaction rate expressions, conservative operating conditions are estimated to guarantee reactor stability, almost complete methane conversion (i.e., minimal unburned hydrocarbon emissions), and a high heat generation rate.