Auto-thermal combustion of lean gaseous fuels utilizing a recuperative annular double-layer catalytic converter

The results of the investigations on the auto-thermal combustion of lean gaseous fuels in a recuperative annular double-layer catalytic converter were reported in the current contribution. Several modifications were proposed to improve the stationary and transient behaviour of the converters. The miniaturized recuperative converter exhibited reduced resistances to the mass and heat transfer and attractive bifurcation changes of a very low combustible content, that is, the histeresis for T-in and C-in and isola for mf(in) and h(g). It was revealed that the utilization of an adiabatic recuperative converter led to an autothermal operation for T-in = 300 K and C-in = 177 ppmv of propane. The inlet fuel mass flow rate range to apply was wider than earlier reported in the literature, that is, 0.63-2.94 x 10(-6) kg s(-1) for C-in = 200 ppmv. Transient experiments showed that recuperative converter was able to transfer short-time inlet disturbances of parameters due to the energy accumulation and temporal reversed recuperation counteracting to extinction or to destructive overheating of the catalysts. Stability analysis was performed showing location of folds, stable and unstable branches of solutions for the different parameters of the recuperative converter. A two-dimensional process model was developed.