Experimental and numerical investigation of a propane-fueled, catalytic mesoscale combustor

Small-scale thermochemical devices driven by hydrocarbon-fueled combustors have attracted increased attention for portable power generation applications due to their superior power density compared to state of the art Li-ion batteries. A combined experimental and numerical investigation is presented for the performance characteristics of a mesoscale, propane-fueled, catalytic combustor, to be used in an integrated, gas-turbine-based, mesoscale (ca. 100W(el)) power generation system. Experiments in an optically accessible reactor led to a global reaction rate for the total oxidation of propane on platinum, valid over the pressure range 1 bar <= p <= 7 bar. Parametric numerical studies were subsequently carried out in a single catalytic channel, using a 2D elliptic code with the aforementioned validated kinetic scheme and all relevant heat transfer mechanisms. The predictions identified favorable materials and operating conditions for the burner under consideration. A subscale monolithic honeycomb reactor was finally constructed, based on the findings of the parametric study. The reactor met the set goals for power output as a function of mass throughput. However, heat losses to the environment were responsible for measuring reduced combustor efficiency at certain operating conditions. A continuum model for the entire monolithic structure complemented the experiments and provided the 2D temperature field. Computed exhaust gas temperatures of the monolith were in good agreement with the measurements. (C) 2010 Elsevier B. V. All rights reserved.