TITLE:
Modeling and Numerical Simulation of Ammonia Synthesis Reactors Using Compositional Approach
AUTHORS:
Diogo Silva Sanches Jorqueira, Antonio Marinho Barbosa Neto, Maria Teresa Moreira Rodrigues
KEYWORDS:
Cubic Equation of State, Adiabatic Converter, Autothermal Converter, Temkin-Pyzhev Expression
JOURNAL NAME:
Advances in Chemical Engineering and Science,
Vol.8 No.3,
July
23,
2018
ABSTRACT: Ammonia synthesis reactors operate in conditions of
high pressure and high temperature. Consequently, the flow inside these
reactors always presents interaction between components in the feed mixture. A
modeling accounts these interactions with pressure, temperature and the molar
fraction is essential to converter simulation more realistic. The compositional
approach based on cubic equations of state provides the influences of the
component of a gas mixture using mixing rules and binary interaction parameters.
This multicomponent description makes the model more robust and reliable for
properties mixture prediction. In this work, two models of ammonia synthesis
reactors were simulated: adiabatic and autothermal. The fitted expression of
Singh and Saraf was used. The adiabatic reactor model presented a maximum
relative error of 1.6% in temperature and 11.4% in conversion while the
autothermal reactor model presents a maximum error of 2.7% in temperature, when
compared to plant data. Furthermore, a sensitivity analysis in input variables
of both converter models was performed to predict operational limits and
performance of the Models for Ammonia Reactor Simulation (MARS).