Porous radiant burner technology in lean combustion systems

A pilot-scale porous burner utilising an alumina-based porous medium has been studied. The system uses a preheated mixture of CO, CO2, and O-2, to which propane (<2% vol., as LPG) is added. The inlet temperature of the mixture has been controlled by an external heat exchanger and set to approximately 400 degreesC. Stable combustion is achieved within the bed. A maximum bed temperature of 1200 degreesC and an exit gas temperature of 1030 degreesC have been recorded. Measured NO, concentrations were < 5ppm. The numerical model PBM has been used to model the combustion kinetics in the porous medium. The model accounts for detailed chemical kinetics and includes radiant, conductive, and convective bed heat transfer. A low temperature gas-phase kinetic scheme with 505 elementary reactions and 90 species has been used, the numerical results were in reasonable agreement with the measured temperature inside the porous medium. In summary, the technology demonstration system has been successful in demonstrating the concept of using porous radiant burner (PRB) technology to enhance the efficiency of power and heat systems by making it possible to reburn very lean mixtures at atmospheric pressure. The good agreement between the numerical results and the experiment enhances the credibility of numerical methods and encourages further development of the PBM code. Integration of the PRB concept in ultra lean technology systems is currently being examined.