Simulation Study of Ammonia Synthesis Loop Reactor-Separator System

The Ammonia recovery is not extremely efficient so the recycled gas typically contains 4.0% mol fraction of Ammonia (Appl.M,2003). Some specific energy is consumed just to recycle small amount of Ammonia back to the Reactor. Thus, the objectives of the project is to simulate and study the Ammonia synthesis loop using iCON® Process Simulation software as well as to investigate the best operating conditions of Ammonia Reactor-Separator System in order to minimize the fraction of unrecovered Ammonia in the recycled gas. The scope of this work focuses on the synthesis and development of the flowsheet for the Ammonia synthesis loop process in PETRONAS‟s iCON® Process Simulation software. The simulated Ammonia synthesis is achieved in Ammonia Reactor at temperature of 250 oC and pressure of 135 atm with 25% reaction conversion. From the simulation, about 6.5% mol fraction of Ammonia is predicted in the recycled gas. The effects of inlet temperature and pressure of Ammonia Reactor-Separator towards the amount of unrecovered Ammonia in the recycled gas were studied. Based on the result, minimum fraction of unrecovered Ammonia in the recycled gas favored at low temperature and high pressure at the inlet stream of Ammonia Separator. The best operating conditions for the inlet stream of Ammonia Separator is deduced at -5.0 oC and 140 kg.f/cm2 respectively. Meanwhile changing the inlet temperature and pressure of Ammonia Reactor does not give significant changes on the fraction of unrecovered Ammonia in the recycled gas. Comparisons of the simulation result are also made with the real plant data from literature.