Numerical analysis of a catalytic radiant burner: Effect of catalyst on radiant efficiency and operability

In this paper we study a new class of porous direct-fired radiant burners which burn part of the fuel catalytically. The burner consists of a multiple-layer porous medium, with one layer that is partially coated with an oxidizing catalyst. Simulations are performed to investigate the effect of platinum catalyst loading, location of catalyst layer, and its thickness on burner performance for single layer and bilayer porous media. Significant efficiency gains are found, but only when the catalyst was placed on the downstream edge of the porous medium. The porous medium was generally not hot enough to cause significant deterioration of the catalyst. Only a thin layer of catalyst is required for efficiency improvements. Enlarging the catalytic zone into cold temperature regions has almost no effect on burner performance. Heat release due to the catalyst occurs inside the porous medium, thus resulting in a higher radiant efficiency.