Geometric parameters effect on the reaction zone of premixed CH_۴ catalytic combustion in a fibrous porous medium

Flameless catalytic heaters are thermal systems in which the chemical energy of gaseous fuel converts into heat with zero NOx and low CO (≤ ۱۰ ppm) emissions. Hence, they are called green heaters in the industry. These heaters benefit from a fibrous porous medium as support for catalyst nanoparticles. Pore structure has a significant effect on transport phenomena inside the porous medium. With the dramatic growth of computers, it is possible to study the impact of geometric detail on combustion phenomena. This study investigates the effect of fiber orientation and diameter on the temperature distribution and the reaction zone of CH۴ catalytic combustion in the fibrous medium. As the fiber axis angle increases from ۱۰° to ۹۰°, the reaction zone moves ۲۴.۱% toward the reactor inlet, the maximum temperature increases by ۶۹.۷ °C, and its distribution becomes more non-uniform. Moreover, as the diameter of the fibers increased from ۵ µm to ۱۰ µm, the reaction site moved ۲۹.۸% toward the end of the reactor, the maximum temperature increased by ۳۴.۹ °C, and its distribution became slightly more uneven. The results showed how the diameter and orientation of fibers influence the performance of porous catalytic reactors. This issue should be considered, especially to increase the life of catalytic burners.

Keywords:

Catalytic Combustion , Fibrous Porous Medium , Fibers Orientation , Fibers Diameter