Effect of Porosity on Combustion Performance in Packed Bed Porous Media

Abstract

This study investigates the effect of packed bed material porosity and air-to-fuel ratio on the combustion stabilization of a premixed gaseous mixture. An experimental work was carried out in a single-layer concept of a packed bed on a constant cross-sectional area tubular burner. Two types of materials, Alumina (Al2O3) and Zirconia (ZrO2), with different porosities, namely 0.36, 0.4, 0.44, and 0.46, were tested. The results showed that porosity has a significant effect on the position of the reaction zones. As porosity decreases, the reaction zone moves downstream of the packed bed. The excess air ratio does not affect the position of the reaction zone but has an impact on the temperature distribution inside the porous medium. The packed bed material affects the volume of the reaction zone and the temperature distribution inside the porous media, where Zirconia has a reaction zone volume higher than Alumina. The concentration of NOx was reduced with increasing porosity. Zirconia media exhibits a lower level of NOx emission compared to Alumina. For an excess air ratio of 1.6, the maximum NOx values were 22.5 and 17.5 ppm for Alumina and Zirconia, respectively.