Numerical Simulation of Ammonia Oxidation for Improved Nitric Acid Yield and Process Efficiency

Mir Ali Asghar Abdollahi¹ Aylin Zarrinbakhsh² Hamed Gharedaghi³ Shaghayegh dadashzadeh⁴ Amir Hatami⁵ Mohamad Reza Aghazadeh⁶

1) Urmia University Email:
2) Shohadaye Farhangi High School Email:
3) University of Tehran Email:
4) Sedigheh Kobra High School Email:
5) Urmia University Email:
6) Islamic Azad University Email:

IOI Code : XKBA-AZEFFD
Publication : 3rd International Conference on Recent Advances in Engineering, Innovation and Technology - Belgium(eitconf.com/3rd)
Abstract :
    This study investigates the ammonia oxidation process within nitric acid production using computational fluid dynamics (CFD). The primary goal is to model the flow dynamics and chemical reactions in an ammonia oxidation reactor. A detailed mesh independence analysis was conducted, identifying an optimal mesh configuration for accurate simulations. The CFD model was validated by comparing simulated mass fractions with reference data, revealing close alignment between simulated and empirical results. The analysis included the distribution of key species like ammonia, nitric oxide, nitrogen dioxide, and oxygen along the reactor length, as well as temperature and NO mass fraction contours on the catalyst surface. The findings highlight non-uniformities in temperature distribution and NO formation across the reactor, which have implications for catalyst performance and reactor efficiency. According to the results, the mass fraction of NO varies by 0.024, and the temperature varies by 75 K across the catalyst surface. This variation indicates a non-uniform flow distribution that adversely affects the reactor’s performance.

Keywords : cfd nitric acid production nitrogen oxide yield discrete ordinates model