Comparative evaluation of spherical radial flow reactor, spherical axial flow reactor, and tubular reactor in ammonia production by using CFD simulation

Computational fluid dynamics (CFD) simulations have been conducted to analyze and compare three configurations of an ammonia synthesis packed bed reactor by simultaneously solving for mass, energy, and momentum conservation in two-dimensional geometry. Since total pressure plays a direct role in species concentrations in gaseous equilibrium reactions, as well as tubular reactors' drawbacks like high pressure-drop and low production capacity, two types of spherical packed bed reactors (axial flow and radial flow) were evaluated in this study as an alternative to tubular reactors. In addition, the tubular reactor (TR) results have been justified by experimental data to validate the proposed model's precision. In the spherical axial flow (SAF) and spherical radial flow (SRF) reactors, nitrogen conversion is enhanced by 32.2% and 26% compared to the TR with the same catalyst weight, respectively. The design parameters of SAF packed beds were examined since they performed better under the same conditions. Also, the SAF production capacity is 1.71 times that of a TR with the same output conversion rate. Finally, by adjusting the inlet temperatures of 640 K, 655 K, and 670 K from the first to third reactors, the SAF has the most efficient performance.