Application of heat interchange systems to enhance the performance of ammonia reactors

A rigorous heterogeneous model for adiabatic ammonia reactors is used to explore the application of internal heat exchange theory to cross the adiabatic reaction equilibrium values and to improve the conversion in ammonia reactors. The mathematical model is developed for adiabatic ammonia converters and the resulting two-point boundary value differential equation for the catalyst particles is solved using the orthogonal collocation method. Two simple configurations of reactors with heat interchangers are implemented. An industrial ammonia reactor having three adiabatic beds with Montecatini Edison catalyst and interstage cooling is used as the basis for comparison. The comparison shows that an increase of 13.37% of the overall ammonia conversion is possible. The results presented in this study reveal the potential application of energy optimization and integration in the ammonia industry. (C) 2000 Elsevier Science S.A. All rights reserved.