The isobaric lean catalytic combustion in a high-pressure recuperative reactor in view of gas turbine technologies is examined. A new type of the T/P bifurcation diagram is revealed and elucidated. It is found that the reactor thermally stabilizes at higher pressures. The elevated P to 0.5 MPa extends bifurcation isola for mfin, i.e. each fold is improved by approximately 15%. The thermal and concentration hysteresis bifurcation diagrams are also improved, i.e. the ignition temperature was decreased from 490 to 475 K and the extinction concentration from 177 to 157 ppmv, respectively. The pressure drops are alleviated by the factor of P/P0 slightly corrected for the gas thermal expansion effect. It is also revealed, that the intra-phase mass transfer resistances are reduced at elevated pressures. The fuel conversion pressure dependences are provided for some types of high-pressure reactors.

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 × 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.Le résultats d'investigation d'auto-thermique combustion du pauvre gazeux combustible dans un convertisseur catalytique récupéré deux-couché aété reporté au présent travail. Plusieurs modifications aété proposé pour améliorer stationnaire et non-stationnaire conduite du convertisseur. Le convertisseur miniaturisé recuperé affiche réduit résistancesá masse et chaud transfert et attractive bifurcation pour trés bas contenu du combustible, that is, histeresis pour T in et C in et isola pour mf in and h g . On a découvré que l'utilization du convertisseur adiabatique recuperé conduitá l'operation autothermique pour T in = 300 K et C in = 177 ppmv du propane. Les limites des mf in pour appliquer aété supérieurá ceux-ci rapporté dans la littérature, that is, 0.63-2.94 × 10 −6 kg s −1 pour C in = 200 ppmv. Le non-stationnaire expérience a indiqué que convertisseur recuperé aété capableá transfert court-temps perturbations des parametres de l'entrée graceá l'accumulation de l'énergie et intermittente recuperation renversé interféreáéteindre ouá destructif surchauffe du cataliseur. L'analyse de stabilité présente arcs, stable et non-stableétat pour les parametres du convertisseur recuperé. Un modèle bidimensionnel du procédé aété développé.

This report was prepared as an account of work sponsored by an agency of the United 9tates gov�rnn1e[)�.

No abstract